(COMPUTER INFO-GALLERYVOLUME - 4(2015-16)

Students Assignments as

IT Encyclopedia

PREFACEThis book is intended to make the new-comers (students) to the Department of

Computer Science (UG), who does not have the ideas regarding the basics of the

Computer and its terminologies. It can also help the students from computer backdrop, to

make a review regarding IT terminologies and concepts. Already 3 Volumes has been

launched during 2012-15.

The thought of publishing this book arises as a sparkle to make the Student’s

Assignments, in an organized manner. I had an idea that, if the topics given to the students

to prepare their Assignments are non-repetitive, then they may do it without copying

others’ content. Then, I thought why not we club it together in the form of a book, which

will help other students also. That is how this book got emerged. This is 4th Volume for the

academic year 2015-16 with some other useful contents to make the students very well

equipped in the foundation level especially for the students who come into the area of

Autonomous.

The copy of this book will be maintained in the Department Library and also the

e-content of this has been posted in our college website. I hereby deliver my heartfelt

thanks to the most respected Correspondent Sir, the honorable Principal Sir, and the

beloved H.O.D. (CS) Prof .P.Ramesh sir, who gave me the freedom, to conduct an activity

of this kind. I thank my colleagues and my senior facultymembers who have given me a

moral support. I also thank my dear students for their co-operation. I hereby assure that the

Department of Computer Science (UG) will always find ways for the betterment of the

students.

Thanking You,

INFO- GALLERY IN-CHARGE

( R.Sundar Raj)

��DEX

Topic No. TOPIC Page No.

01 ASYMMETRIC DIGITAL SUBSCRIBER LINE (ADSL) 0102 ADWARE 0303 ACCELERATED GRAPHICS PORT (AGP) 0504 APPLICATION PROGRAMMING INTERFACE (API) 0705 BASE STATION 0906 BATCH FILE 1107 BLIND CARBON COPY (BCC) 1308 BETA SOFTWARE 1509 BING SEARCH ENGINE 1710 BITTORRENT 1911 BINARY LARGE OBJECT (BLOB) 2112 BLOG 2313 BOOT DISK 2514 BUFFER 2715 BURNING A DISC 2916 CAPTCHA 3117 CACHE MEMORY 3318 COMPUTER AIDED DESIGN (CAD) 3519 CHARGE COUPLED DEVICE (CCD) 3720 COMMON GATEWAY INTERFACE (CGI) 3921 CHIPSET 4122 CHARACTER LARGE OBJECT (CLOB) 4323 CLOCK CYCLE 4524 CLONE SOFTWARE 4725 CLOUD COMPUTING 4926 CLUSTER 5127 COMPUTER DAEMON 5328 DATA TRANSFER RATE 5529 DATA TYPES 5730 DATA DEFINITION LANGUAGE (DDL) 59

Topic No. TOPIC Page No.

31 DIAL-UP CONNECTION 6132 DIALOG BOX 6333 DIGITAL SIGNATURE 6534 DIRECT 3D 6735 DIRECT MEMORY ACCESS (DMA) 6936 DOMAIN NAME SYSTEM (DNS) 7137 DONGLE (ADAPTER) 7338 EMOTICON 7539 ENCAPSULATED POST SCRIPT (EPS) 7740 EXPANSION CARD FOR PRINTERS 7941 FILE ALLOCATION TABLE (FAT) 8142 FLAT FILE 8343 GEOGRAPHIC INFORMATION SYSTEMS (GIS) 8544 GNUTELLA NETWORK 8745 GOOGLE DRIVE 89

BESTWISHES

To all of your present and future innovations for

the betterment of our students and the Institution

H.O.D Principal Correspondent

Assignment Contributions

Class : I B.Sc (CS) - 'A'

S.No Name Topic No. page No.01 ANANDHI .B .M 01 0102 PRIYA .P 02 0303 HARIHARAN .E 03 0504 MUHAMUDHA SHILFA .M 04 0705 VINOTHAN .S 05 09

Under the guidance of : Mr. A.R.karthekeyan

Class : I B.Sc (CS) - 'B'

S.No Name Topic No. page No.06 NANDHA KUMAR ARASU .V 06 1107 PRAVIN RAJA .L 07 1308 PRABHU .A 08 1509 LOGESHWARAN .V 09 1710 SANJOY .S .M 10 19

Under the guidance of : MS. V.MANIMEKALAI

Class : I B.Sc (CS) - 'C'

S.No Name Topic No. page No.11 SREEMATHI .S 11 2112 SURESH KUMAR .P 12 2313 DHARSHNE .M 13 2514 MUTHUMANIKANDAN .B 14 2715 CHAITHRA .B.R 15 29

Under the guidance of : MS. P.THENMOZHI

Class : II B.Sc (CS) - 'A'

S.No Name Topic No. page No.16 HARSHINI .U.D 16 3117 BHAVANIVETHA .C 17 3318 PRIYADHARSHINI .S .M 18 3519 HARIHARAN .P 19 3720 KARUPPUSAMY .P 20 39

Under the guidance of : MS. R.PUSHPALATHA

Class : II B.Sc (CS) - 'B'

S.No Name Topic No. page No.21 HEMA .J 21 4122 MYTHILI .R 22 4323 SIVAKUMAR .G. C 23 4524 DHARANI SREE .S 24 4725 KARTHIKEYAN .M 25 49

Under the guidance of : MS. R.SAVEETHA

Class : II B.Sc (CS) - 'C'

S.No Name Topic No. page No.26 PAVITHRA .P 26 5127 JITHIN JOY 27 5328 BALAKUMAR .V 28 5529 NAVIN KUMAR .S 29 5730 MEENAPRIYA .N 30 59

Under the guidance of : MR. D.GOPINATH

Class : III B.Sc (CS) - 'A'

S.No Name Topic No. page No.31 NAVEEN KUMAR .R 31 6132 ANANDHARAJ .P 32 6333 KEERTHANA .V 33 6534 VIMALA .M 34 6735 RAMYA .P 35 69

Under the guidance of : MS. S.GOWTHAMI

Class : III B.Sc (CS) - 'B'

S.No Name Topic No. page No.36 MEENA .S .P 36 7137 PRASANTH .S 37 7338 ARTHI .T 38 7539 SURESH .E 39 7740 DEEPIKA .K 40 79

Under the guidance of : MS. K.GOMATHY

Class : III B.Sc (CS) - 'C'

S.No Name Topic No. page No.41 MANIKANDAKARTHI .G 41 8142 VIGNESH .K 42 8343 SANDHIYA .C 43 8544 SNEHA .M 44 8745 DINESH BALAJI .S 45 89

Under the guidance of : MR. T.VELUMANI

01. ASYMMETRIC

Introduction

Asymmetric digsubscriber line (DSL) tecenables faster data transmisvoice band modem. The 'Abandwidth between downlo1.5 to 9 Mbps when receiviwhen sending data (upstrereceive Internet access in a direction for the download

Overview

ADSL works by utilizcall. A special filter, callsubscriber's telephone lineservices to be used at the sconnection are that, firstly,be uploaded than downloaavoid overloading of their buses such as file sharing whcommunication is full-dup

�

IC DIGITAL SUBSCRIBER LINE

digital subscriber line (ADSL) is a typtechnology, a data communications techmission over copper telephone lines than a 'A' in ADSL refers to the unequal distribunloads and uploads. ADSL supports data riving data ( downstream rate) and from 16 stream rate). ADSL as a service for co a relatively passive mode: able to use the

ad from the internet.

ilizing frequencies that are not used by a voialled a micro filter or DSL filter, is inne to allow both ADSL and regular voicee same time. The marketing reasons for anly, most uses of internet traffic will requireloaded Secondly internet service providersir backbone connections, have traditionally which generate a lot of uploads. Currently,uplex. Full-duplex ADSL communication

E (ADSL)

type of digitalechnology that a conventional

ribution networkta rates of from16 to 640 Kbps

r consumers tohe higher speed

voice telephone installed on aice (telephone)

r an asymmetricire less data toers, seeking to

lly tried to limittly, most ADSLtion is usually

achieved on a wire pair cancelling duplex (ECD), o

Operation

The total maximum reported by DSL modems a

ADSL initially exnamely CAP and DMT. CAup until 1996, deployed However, DMT was choseG.992.2 (also called G.dminstallations of ADSL are b

Purpose

ADSL is designdownloads large amounts uploads relatively less often

In other respecassociates with DSL, includof voice and data support,physical distance. Since thdownload speed, the telenecessity, hence ADSL.

�

ir by either frequency-division duplex (FD), or time-division duplex (TDD).

m capacity derived from summing the bis and is sometimes termed sync rate.

existed in two versions (similar CAP was the de facto standard for ADSL d in 90 percent of ADSL installations osen for the first ITU-T ADSL standards, .dmt and G.lite respectively). Therefore

re based on the DMT modulation scheme.

igned to support the typical home user whts of data from Web sites and online n

ften.

pects, ADSL possesses all of the characluding high-speed service, an "always on" rt, and availability and performance that i

e the typical home user in fact does preelephone companies chose to make a v

(FDD), echo-

bits-per-bin is

ar to VDSL),SL deployments

s at the time.s, G.992.1 andre, all modern

.

who frequently networks but

racteristics onen" combinationat is limited byprefer a higher virtue out of

Adware is free softwadware programs are toolbarsyour Web browser. They inyour hard drive and better or

Adware is software thcontrols on the internet. Adwto display advertisements oadvertising websites, and col

Adware, or advertisiautomatically renders adverThe term is sometimes uadvertisements known as m

Adware has been crituser’s personal information

authorization or knowledgprompted an outcry from coElectronic Privacy Informa

�

02. ADWARE

ftware that is supported by advertisemebars that sit on your desktop or work in con include features like advanced searching or organization of your bookmarks and shortc

that is installed together with software odware is the name given to programs that

s on your computer, redirect your searchcollect marketing-type data about you.

tising-supported software, is any software vertisements in order to generate revenue fs used to refer to software that displays malware.

riticized because it usually includes code ion and passes it on to third parties, witho

dge. This practice has been dubbed spyw computer security and privacy advocates, i

rmation Center.

ments. Commonconjunction withg of the Web orrtcuts.

or via activexat are designedrch requests to

re package thate for its author.lays unwanted

de that tracks athout the user’s

yware and hass, including the

�

Two mainways of ways in which Adware can get onto your computer

Via freeware or shareware: Adware can be included within somefreeware or shareware programs-as a legitimate way of generatingadvertising revenues that help to fund the development and of thefreeware or shareware program.Infected websites: A visit to an infected website can result inunauthorized installation of Adware on your machine. Hackertechnologies are often used. For instance, your computer can bepenetrated via browser vulnerability, and Trojans that are designed forstealthy installation can be used. Adware programs that work in this wayare often called Browser Hijackers.

Anti-Adware

Anti-adware refers to any software utility that scans your system andremoves adware, spyware, key loggers, Trojans, and other malicious code fromyour computer. Some of these programs are undetectable to anti-virus softwareand many users now use an anti-adware utility in addition to anti-virus softwareto protect their system.

Difference Between Spywares, Malwares, Adwares &Trojan

Spywaresare the programs which are used to monitor/Log the activityperformed on a computer. These are used to spy on someone either forlegal or illegal purpose.

Example: Key logger applications.

Malwares are the program with malicious intention. It can be damagingyour computer, spying on you or any other malicious taskAdwares are the programs which delivers ads to your computer(generally in POP-UP’s form). They consume your network.

Trojan is a program which is used to gain access to a computer byinstalling a program on infected PC to open some backdoor.

03. ACCELERWhat is AGP?

The Accelerated Grapoint-to-point channel for attassist in the acceleration of 3

It was originally desigcards.

History

The AGP slot first aSocket 7 Intel P5Pentium ansupport with the i440lx Slot

The first Socket 7 ch5591/5592, and the ALI Alad

FIC demonstrated theas the FIC PA-2012 based oby the epox P55-VP3 also market.

Early video chipsets feV2200, 3dfxvoodoo BansheATI Rage series, Matrox Mil

�

ERATED GRAPHICS PORT (AGP

raphics Port (often shortened toAGP) isr attaching a video card to a computer systemf 3D computer graphics.

signed as a successor to PCI-type connect

t appeared on x86-compatible system boaand Slot 1P6Pentium II processors. Intel intot 1 chipset on August 26, 1997. chipsets to support AGP were the viaapladdin V.

the first Socket 7 AGP system board in Nod on the VIA Apollo VP3 chipset, followedlso based on the VIA VP3 chipset which

ts featuring AGP support included the Renshee, nvidiariva 128, 3Dlabs PERMEDIA Millennium II, and S3 virge GX/2.

GP)

) is a high-speedtem, primarily to

ections for video

boards based on introduced AGP

aapollo VP3, sis

November 1997ed very quickly

ich was first to

Rendition VeriteIA 2, Intel i740,

6

Versions

AGP and PCI: 32-bit buses operating at 66 and 33 MHz respectively

Specification Voltage Clock SpeedTransfers/clock Rate (MB/s)

PCI 3.3/5 V 33 MHz — 1 133

PCI 2.1 3.3/5 V 33/66 MHz — 1 266

AGP 1.0 3.3 V 66 MHz 1× 1 266

AGP 1.0 3.3 V 66 MHz 2× 2 533

AGP 2.0 1.5 V 66 MHz 4× 4 1066

AGP 3.0 0.8 V 66 MHz 8× 8 2133

AGP 3.5* 0.8 V 66 MHz 8× 8 2133

Power consumption

AGP power provisioning

Slot Type 3.3 V 5 V 12 V 3.3 V Aux 1.5 V 3.3 V 12 V Total power

AGP 6 A 2 A 1 A 0.375 mA 2 A - - 48.25 W

AGP Pro110 7.6 A 9.2 A 50 to 110 W

AGP Pro50 7.6 A 4.17 A 25 to 50 W

Legacy useBy 2010 few new motherboards had AGP slots. No new motherboard

chipsets were equipped with AGP support, but motherboards continued to beproduced with older chipsets with support for AGP.

Graphics processors of this period use PCI-Express, a general-purpose (notrestricted to graphics) standard that supports higher data transfer rates and full-duplex.

7

04 .APPLICATION

API Stands for "Appreferred to as an "Applicacommands, functions, and psoftware for a specific opera

API in Object Oriented La

Object API is a descrilanguage- usually it isclass methods.

For example:

In Java if the class Scin text-based programsThe API can be conexposed by the classes

API Libraries and Framew

An API is usually represcribes the expeimplementation of this

7

ON PROGRAMMING INTERFACE

pplication Program Interface," though it lication Programming Interface." An API d protocols which programmers can use werating system.

d Language

scription of how object works in a given ot is expressed as a set of classes with an ass

Scanner is to used(a class that reads inputsms)onceived of as a totality of all the metses called an interface.

ework

related to a software library. The API xpected behavior while the library ithis set of rules.

7

CE (API)

it is sometimesPI is a set of

e when building

n object-orientedassociated list of

uts from the user

ethods publicly

PI describes and is an actual

8

API can also be related to a software framework. The overall program flowof control can be out of the control of the caller, and in the hands off theframework inversion of the control or a similar mechanism.

API In Design

API’s proposed the concept of information hiding in 1972. Principle of

information hiding is that one may divide software into modules, each ofwhich has a specified interface.Software architecture is dedicated to creating and maintaining high levelsoftware structures which typically include modules.API are designed in the real world, one must also understand the structuresof software engineering organization.

API in Documentation

Professional-level documentation for an API should strive to include the followingparts:

Reference documentation:A description of the function and objects in the API

Overview and concepts:A narrative description of the different parts of the API and howthey interact. Major frame works in the API, such as its GUI,network and file system frameworks should have their ownseparate section.

SDK tools documentation:Documents that describe how to install and use build, compile, anddeploy tools

License information:Documents that describe the API license

9

Introduction

The term "base stationside of the road that relay cemade within their area, retransmitting it to the other.

A base station is thewired phones. It's what allophone.

The base station, a wi

A 1980s cons

The term base stationcomputer networking and otin surveying it is a GPScommunications it is a transanother and/or to a wider are

In a computer networkthe network, possibly connec

9

05. BASE STATION

tion" was first used to refer to the towers y cell phone calls. These stations handle all

receiving information from one end of r.

the interface between wireless phones anallows you to use your cell phone to call

wireless system, uses microwave radio com

onsumer-grade Citizens' band radio (CB) base station

on is used in the context of mobile telepho other wireless communications and in lan

PS receiver at a known position, while ransceiver connecting a number of other dearea.

ork it is a transceiver acting as a router fornecting them to a local area network and/or

9

rs you see on the all cellular callsof the call and

and traditionalcall your home

ommunication.

phony, wirelessland surveying:ile in wireless

r devices to one

for computers in/or the internet.

10

Land surveying

In the context of exteran accurately-known fixed lofor nearby portable GPS rece

Computer networking

In the area of wirelereceiver/transmitter that servalso be the gateway between

Wireless communications

In radio communicatioinstalled at a fixed locate Teof one of the following:

Media

Close-up of a base City, Mexico. There are thre120-degree segment of the hlinks the site with the telepho

10

ternal land surveying, a base station is a GPSd location which is used to derive correctionreceivers.

reless computer networking, a base statioerves as the hub of the local wireless netwen a wired network and the wireless networ

s

ations, a base station is a wireless communicTerrestrial Trunked ion and used to commu

e station antenna in Mexicothree antennas: each serves ae horizon. The microwave dishphone network.

10

GPS receiver ation information

ation is a radioetwork, and mayork.

nications stationmunicate as part

11

06. BATCH FILE

Meaning

A batch file is a kind of script file in DOS, OS/2 and Windows. It consists ofa series of commands to be executed by the command line interpreter stored ina plain text file. A batch file may contain any command the interpreter acceptsinteractively and use constructs that enable conditional branching and loopingwithin the batch file, such as "if", "for", "go to" and label similar to Job ControlLanguage (JCL) and other systems on mainframe and minicomputer systems, batchfiles were added to ease the work required for certain regular tasks by allowing theuser to set up a script to automate them. When a batch file is run, the shell program(usually COMMAND.COM or cmd.exe) reads the file and executes its commands,normally line-by-line.

Unix-like operating systems (such as Linux) have a similar but moreflexible type of file called a shell script. The filename extension .bat is used inDOS and Windows. Windows NT and OS/2 also added .cmd. Batch files for otherenvironments may have different extensions,e.g. .btm in 4DOS, 4OS2 and 4NT related shells. The detailed handling of batchfiles has changed. Some of the detail in this article applies to all batch files whileother details apply only to certain versions.

DOS

In MS-DOS, a batch file can be started from the command line by typing itsname followed by any required parameters and pressing the "enter" key. WhenMS-DOS loads, the fileAUTOEXEC.BAT is automatically executed. So anycommands that need to be run to set up the MS-DOS environment for use could beplaced in this file. Computer users would have the autoexec file set up the systemdate and time, initialize the MS-DOS environment, load any resident programs ordevice drivers, or initialize network connections and assignments.

In MS-DOS the extension ".bat" identified a file containing commandswhich could be executed by the command interpreter COMMAND.COM line byline as if it was a list of commands to be entered, with some extra batch-file-specific commands for basic programming functionality, including a GOTOcommand for changing flow of line execution.

12

Early windows

Microsoft Windows was introduced in 1985 as a GUI-based alternative totext-based operating systems and was designed to run on MS-DOS. In order tostart it, the win command was used, which could be added to the end ofthe AUTOEXEC.BAT file to allow automatic loading of Windows. In the earlierversions, one could run a .bat type file from Windows in the MS-DOSPrompt. Windows 3.1x and earlier, as well as Windows 9x invokedCOMMAND.COM to run batch files.

OS/2

The IBM OS/2 operating system supported DOS-style batch files. It alsoincluded a version of REXX, which was a more advanced batch-file scriptinglanguage. IBM and Microsoft started developing this system, but during theconstruction of it broke up after a dispute; as a result of this, IBM referred to theirMS-DOS-like console shell without mention of Microsoft, naming it just DOS,although this seemingly made no difference with regard to the way batch filesworked from COMMAND.COM. OS/2's batch file interpreter also supports anEXTPROC command. This passes the batch file to the program named on theEXTPROC file as a data file. The named program can be a script file.

Windows NT

Unlike Windows 9x and earlier, the Windows NT family of operatingsystems does not depend on MS-DOS. Windows NT introduced an enhanced 32-bit command interpreter (cmd.exe) which could execute scripts with either the.CMD or .BAT extension. Cmd.exe added additional commands, and implementedexisting ones in a slightly different way, so that the same batch file (with differentextension) might work differently with cmd.exe and COMMAND.COM. In mostcases, operation is identical if the few unsupported commands are not used.Cmd.exe's extensions to COMMAND.COM can be disabled for compatibility.Microsoft released a version of cmd.exe for Windows 9x and ME calledWIN95CMD to allow users of older versions of Windows to use certain cmd.exe-style batch files.

As of Windows 8, cmd.exe is the normal command interpreter for batchfiles; the older COMMAND.COM can be run from within a cmd.exe window in32-bit versions of Windows able to run 16-bit programs.

13

07. BLI

Definition of blind carbon c

BCC Stands for "Blindperson, you type the recipimessage to more than one p"Cc:" and "Bcc:" fields. "Cc"Blind Carbon Copy." A carto one or more recipients. Bfield) and the Cc'd recipienWhen a message is blind carecipients can see the addres

Blind carbon copyingwithout the main recipient kand then forwarding the senetiquette to use Bcc when e-mail addresses from beingfor spamming purposes. Howsent a message, use carbon c

13

LIND CARBON COPY (BCC)

n copy

lind Carbon Copy." When you send an e-macipient's address in the "To:" field. Whene person, you have the option to enter ad"Cc" stands for "Carbon Copy," while "Bccarbon copy, or "Cc's" message is an e-mail. Both the main recipient (whose address iients can see all the addresses the message carbon copied, neither the main recipient resses in the "Bcc:" field.

ing is a useful way to let others see an e-t knowing. It is faster than sending the ori sent message to the other recipients. It en copying a message to many people. Thiing captured by someone in the list who mowever, if it is important that each recipie

n copy (Cc) instead.

13

-mail to only onehen you send aaddresses in the"Bcc" stands forail that is copieds is in the "To:"age was sent to.nt nor the Bcc's

e-mail you sentoriginal message It is also goodhis prevents the might use thempient knows who

14

Advantages of blind carbon copy

1. To send an email to the second person without the first person knowing2. Sending through a Mailing List or Newsletter3. Protecting the second person by not sharing their email address to the first

Person

Benefits

There are a number of reasons for using this feature:

• Bcc is often used to prevent an accidental "Reply All" from sending a replyintended for only the originator of the message to the entire recipient list.

• To send a copy of one's correspondence to a third party (for example, acolleague) when one does not want to let the recipient know that this isbeing done (or when one does not want the recipient to know the thirdparty's e-mail address, assuming the other recipient is in the To: or Cc:fields).

• To send a message to multiple parties with none of them knowing the otherrecipients. This can be accomplished by addressing a message to oneself andfilling in the actual intended recipients in the Bcc: field. However, this doesnot ensure that the Bcc: addresses will be hidden from other Bcc: addressesin all implementations.

• To prevent the spread of computer viruses, spam, and malware by avoidingthe accumulation of block-list e-mail addresses available to all Bcc:recipients, which often occurs in the form of chain letters.

Disadvantages of blind carbon copy

In some cases, use of Blind Carbon Copy may be viewed as mildlyunethical. The original addressee of the mail (To: address) is left under theimpression that communication is proceeding between the known parties, and isknowingly kept unaware of others participating in the primary communication. Arelated risk is that by (unintentional) use of 'reply to all' functionality by someoneon Bcc, the original addressee is (inadvertently) madeaware of this participation.For this reason, it is in some cases better to separately forward the original e-mail.

15

0

Definition of beta software

A pre-release of softwunder real conditions. Beta vare generally fairly close in design changes often occur a

Advantages and disadvanta

The Beta version of errors, bugs and crashes can it helps to enhance the softproduct/software is launcheAnother advantage of the safeedback. Imagine a companusers, and then paying thecompany.

Also, even if the comwould always be a considerasoftware globally would tak

15

08. BETA SOFTWARE

re

ftware that is given out to a large group ota versions have gone through alpha testingin look, feel and function to the final prodr as a result.

ntages of beta software

of any software is made available globaan be reported by real time users. This is adoftware performance and make it failure freched on a larger scale with a high perfo same is that it provides a fast and less co

pany employing so many testers as there arethem. This would sum up to a huge am

ompany does appoint so many testers, the deration and a point of concern. Many peotake very less time, and the varied dimensi

15

p of users to trying in house and

roduct. However,

bally so that its advantageous ase free when theerformance rate. costly software are beta versionamount for the

he time durationpeople using thensions of testing

16

would be highly fruitful. Allof renting a disk space on the

About beta software

Find beta releases all apps, music players, etc.

development and to comparethrough multiple phases: egg

As products develop, and release candidate. Usag

IBM as early as the 1950s.cycle before, but let’s delve a

The pre-alpha phase

The pre-alpha phase first round of testing. Of cotesting products in an iterati

the pre-alpha phase refers toThis phase encapsula

collection, requirements asoftware engineering. That’

gives an idea of how mucdevelopment.

16

All the costs that the company has to bear the internet and good popularity of the prod

all over the place: operating systems, videc. The term “beta” refers to a produc

pare it to the life cycle of insects, which tggs, larva, pupa, and adult.

p, they go through a similar cycle: pre-alphsage of the “alpha/beta” labeling can be t

0s. It may have heard about the softwaree a little deeper into what these terms mean

se is the portion of development that occuf course, a properly managed project will rative manner, so I suppose it’s more accura

to everything that happens before official tulates many different activities: market r analysis and documentation, software at’s probably a load of mumbo-jumbo, buuch work is involved even before a p

16

ar would be thatroduct.

ideo games, webduct’s stage of

h typically goes

lpha, alpha, beta,e traced back to

are developmentean.

ccurs before theill constantly beurate to say that

al testing begins.t research, datare design, and but hopefully it product begins

17

09. B

Bing (known previouSearch) is a web search engin

Features

Interface features

Daily changing of bacplaces in the world, sports. The backgroelement(s) shown in thVideo homepage for Hto the daily backgrounSublinks – On certaisection links within tincluding Google).Enhanced view whereBing.On certain sites, searchOn certain sites, Binresults page.

17

. BING SEARCH ENGINE

ously as Live Search, Windows Live Seargine from Microsoft.

background image. The images are mostly rld, though it sometimes displays animalsground image also contains information the image.r HTML5 enabled browsers on occasional eund images.

rtain search results, the search result pagn the article (this is also done on other se

here third party site information can be v

rch from within the website on the results pBing will display the Customer Service n

17

Search, and MSN

ly of noteworthyals, people, andtion about the

al events, similar

age also shows search engines,

e viewed inside

ts page. number on the

18

Media features

Video thumbnail Preview– where, by hovering over a video thumbnail, thevideo automatically starts playing.Advanced filters or advanced (query) operators– allow users to refine searchresults based on properties such as image size, aspect ratio, color or blackand white, photo or illustration, and facial features recognitionVideo search with adjustable setting for length, screen size, resolution, andsource

Integration with Hotmail

With Hotmail’s "Quick Add" feature, users can insert derivatives of Bingsearch results such as restaurant reviews, movie times, images, videos, andmaps directly into their e-mail messages.

Integration with Facebook

Bing's search results can display one's Facebook friends when a Facebookaccount is linked with Bing via Facebook Connect.Users have the option to send messages to their friends in the search results.As part of the changes announced May 10, 2012 the "sidebar" column of thenew three-column search results display will include recommendations fromFacebook and the ability to interact with others from the same page.For the previous year, search results had included Facebookrecommendations using the "like" button, but most users did not want this;the new display makes this feature separate from search results in general.

Integration with Apple

Apple's search results have now been integrated with Bing's web searchengine.On June 10, 2013, Apple announced that it will be dropping Google as itsweb search engine and include Microsoft's Bing.This feature is only integrated with ios 7 and higher and for users with aniphone 4S or higher as the feature is only integrated with Siri, Apple'spersonal assistant.

19

Definition of bittorrent

BitTorrent is a peer-tothe bandwidth required to traacross multiple systems, thecomputer. For example, if asystem will locate multiple the file from several compdownload speeds than uploasignificantly increase the file

In order to use the Biis a software program that allows you to search for fiprogress downloads. Most have been paused or stoppelarge files.

About bittorrent

BitTorrent Inc. is an InThe design distributed technedge, and keep creators andthan 170 million people usmuch as 40% of the world's I

It is used to build anations to create better ways

19

10. BITTORRENT

r-to-peer (P2P) file sharing protocol desigo transfer files. It does this by distributingthereby lessening the average bandwidth f a user begins downloading a movie file, tle computers with the same file and beginmputers at once. Since most ISPs offer load speeds, downloading from multiple cfile transfer rate.

BitTorrent protocol, you need a BitTorrentat accesses the BitTorrent network. The cr files and begin downloading torrents, wst BitTorrent clients allow you to resumeped. This can be especially helpful when

n Internet technology company based in Schnologies that scale efficiently, keep intelnd consumers in control of their content anuse our products every month. Our proto's Internet traffic on a daily basis.

a better Internet. To work with people, iys to move information. Better ways for cre

19

signed to reduceing file transfersth used by eache, the BitTorrentgin downloadingffer much fastere computers can

rent client, whiche client program, which are in-me torrents thaten downloading

n San Francisco.telligence at thet and data. More

rotocols move as

e, industries andr creators to make

20

money. New ways for fans to engage, on their terms. Ways to sustain the stuff weshare. The Internet promised us this much. And we promise to make good on it.We believe in an Internet of options, not rules.

Bittorrent DNA

BiTorrent DNA is a disruptively effective content delivery technology. Itsignificantly reduces bandwidth costs for popular files while dramaticallyimproving the performance and scalability of websites. BitTorrent DNA enableswebsites to seamlessly add the speed and efficiency of patented BitTorrenttechnology to their current content delivery infrastructure, requiring no changes totheir current Content Delivery Network (CDN) or hardware in the origininfrastructure.

Businesses can benefit from the efficiencies of peer-assisted contentdelivery while improving the end-user experience.

The BitTorrent Certified program includes a Software Development Kit(SDK) for consumer electronics manufacturers; ensuring compatibility betweenconsumer electronics products, and the BitTorrent ecosystem of services andsoftware. Compatible devices are eligible for the BitTorrent Certified logoendorsement, which allows manufacturers to leverage the BitTorrent brand forpackaging and promotional materials.

Advantages of bittorrent:

Highly EfficientMakes sharing easierPrevents tampered or broken files from being sharedAbility to download and upload large files in a shorter amount of timeFree uploading and downloading

Disadvantages of bittorrent:

If the seeder leaves the swarm too early, no one is able to use the fileSeeder can only seed one or two files at a timeThe computer's performance drops drastically while using the programOld or unpopular files are hard to findTorrent files are too flaky due to excessive popularity

21

11. BINA

A Binary Large OBjesingle entity in a dtypically images, audio or oexecutable code is stored as a

"Blobbing" originallydatabase to another without the responsibility for error chterm arose from the image container and putting it in awere grasping.

21

ARY LARGE OBJECT (BLOB)

Bject (BLOB) is a collection of binary daa database management system.

r other multimedia objects, though someas a blob. Database support for blobs is not

lly meant moving large amounts of daut filters or error correction. This is fast br checking and filtering on the new host for ge of somebody grabbing fistfuls of maten another without regard to what was in th

21

data stored as aBlobs are

metimes binaryot universal.

data from onet because it putsfor the data. Theaterial from one the "blob" they

22

The data type and defidefined in traditional compularge to store practically at defined in the 1970s and 19became cheap. This definitio

Blobs were originallyStarkey at DEC, who describor whatever" from "the 1958Terry McKiever, a marketiacronym and invented the baan alternative backronym, Bi

22

definition was introduced to describe data puter database systems, particularly becau

at the time the field of database systems w 1980s. The data type became practical whition gained popularity with IBM's DB2.

lly just big amorphous chunks of data invcribes them as "the thing that ate Cincinna58 Steve McQueen movie", referring to Theting person for Apollo, felt that it neebackronym Basic Large Object. Then Info

, Binary Large Object.

22

ta not originallycause it was toos was first beingwhen disk space

invented by Jimnnati, Cleveland,The Blob. Later,eeded to be an

Informix invented

23

12. BLOG

A blog (a truncation of the expression weblog) is a discussion orinformational site published on the consisting of discrete entries ("posts") typicallydisplayed in reverse chronological order (the most recent post appears first). Until2009, blogs were usually the work of a single individual occasionally of a smallgroup, and often covered a single subject. More recently "multi-author blogs"(MABs) have developed, with posts written by large numbers of authors andprofessionally edited. MABs and other media outlets, and similar institutionsaccount for an increasing quantity of blog traffic.

The rise of and other systems helps integrate MABs and single-author blogsinto societal new streams. Blog can also be used as a verb, meaning to maintain oradd content to a blog.

The emergence and growth of blogs in the late 1990s coincided with theadvent of web publishing tools that facilitated the posting of content by non-technical users. Majority are interactive, allowing visitors to leave comments andeven message each other via on the blogs, and it is this interactivity thatdistinguishes them from other static websites. In that sense, blogging can be seenas a form of indeed, bloggers do not only produce content to post on their blogs,but also build social relations with their readers and other bloggers. However, thereare high-readership blogs which do not allow comments.

Many blogs provide commentary on a particular subject; others function asmore personal; others function more as a part of a particular individual orcompany. A typical blog combines text, images, and links to other blogs, and othermedia related to its topic. The ability of readers to leave comments in an interactiveformat is an important contribution to the popularity of many blogs. Most blogs areprimarily textual, although some focus on art, photographs videos or music andaudio is another type of blogging, featuring very short posts. In education, blogscan be used as instructional resources.

On 16 February 2011, there were over 156 million public blogs in existence.On 20 February 2014, there were around 172 and 75.8 million blogs in existenceworldwide. However, Blogger does not offer public statistics.

24

The Difference Between a Bl

Software that providecalled a CMS or "Contenprograms are considered asrequired to create and maintsimple as writing an article, categories.

While some CMS problogging tool provides an indegree, intuitive manner whcomposition presentable andwhat you want to write, anmanagement.

Word Press is one sucfeatures. Through its Adminand presentation of your wecompose a blog post, push Word Press goes to great paibeautiful, and the html codestarting out, read Getting Stahow to get Word Press set performing basic tasks withexisting ones.

24

n a Blog and CMS?

ides a method of managing your website tent Management System". Many bloggas a specific type of CMS. They provid

intain a blog, and can make publishing on le, giving it a title, and organizing it under

programs offer vast and sophisticated fea interface where you can work in an easywhile it handles the logistics involved innd publicly available. In other words, you gand the blogging tool takes care of the re

such advanced blogging tool and it provideinistration Panels, you can set options for

weblog. Via these Administration Panels, ysh a button, and be published on the interpains to see that your blog posts look good,de it generates conforms to web standards.

Started with Word Press, which contains inet up quickly and effectively, as well as inithin Word Press, like creating new po

24

ite is commonlyogging softwareide the featuresn the internet aser (one or more)

features, a basicsy and, to some

in making youru get to focus on rest of the site

ides a rich set of for the behaviors, you can easilyternet, instantly!od, the text looksrds. If you're justs information ons information onposts or editing

25

13. BOOT DISK

A boot disk is removable digital data storage medium from which one canload and run a utility program. The computer must have a built-in program whichwill load and execute a program from a boot disk meeting certain standards.

Uses of Boot disks

• Operating system installation• Hardware or software troubleshooting• Customizing an operating environment• Software demonstration• Administrative access in case of lost password is possible with an

appropriate boot disk with some operating systems• Games• While almost all modern computers can boot from a hard drive containing

the operating system and other software, they would not normally be calledboot disks are the most common forms of media used, but other media, suchas magnetic or paper tape drives, , and more recently can be used. Thecomputer's must support booting from the device in question.

The process of booting

The term boot comes from the idea of lifting oneself by one's own thecomputer contains a tiny program (bootstrap loader) which will load and run aprogram found on a boot device. This program may itself be a small programdesigned to load a larger and more capable program, i.e., the full operating system.To enable booting without the requirement either for a device or to write to theboot medium, it is usual for the boot program to use some system as a temporarystorage. As an example, any computer compatible with this is able with built-insoftware to load the contents of the first 512 bytes of a floppy and to execute it if itis a viable program; boot floppies have a very simple loader program in thesebytes. The process is vulnerable to abuse; data floppies could have a virus writtento their first sector which silently infects the host computer if switched on with thedisk in the drive.

26

Boot floppies

Bootable floppies for PCscommonly available floppy making it impractical for loato the availability of other hi

Booting from a disk

A modern PC is conficertain order. If a computer floppy drive, the user may special key when the compuF12), and then changing theof the final stage of the boot results in a list of bootable dmade.

Modern Apple compupresses the C key while the m

26

or PCs usually contain or miniature versionspy disk can hold only 1.4 of data in its staloading large. The use of boot floppies is i

r higher-capacity options.

onfigured to attempt to boot from variouster is not booting from the device desiredy have to enter the BIOS setup function puter is first turned on (such as Delete, F

the boot order. More recent BIOS permit thot process by pressing a function key (usua

e devices being presented, from which a sel

puters will boot from an appropriate dise machine is starting.

26

ons of. The moststandard format,

is in decline, due

ous devices in aired, such as then by pressing a, F1, F2, F10 ort the interruptionsually F11). Thisselection may be

disk if the user

27

14. BUFFER

A buffer is a temporary holding area for data while it's waiting to betransferred to another location. It is usually located in the RAM. The concept of thebuffer was developed in order to prevent data congestion from an incoming to anoutgoing port of transfer.

There are common uses for the buffer that help improve a device's overallperformance. Nearly all hard disks make use of a buffer to facilitate easy retrievalof data. Any type of memory handling and data storage service will make use ofsome sort of buffer as well.

Even the CPU's most basic tasks need to use buffers to operate in the formof registers, where data like operands and operators are stored before they areprocessed. When a user downloads a video or audio file, a certain percentage of thedownloaded file is placed in the buffer and then played. As the clip is played, thedevice continuously downloads the file and places it in the buffer. Because of this,there is less chance that the video or audio file will stall when network congestionoccurs, unless of course the download rate is so slow that the play speed catches upwith it. As another example, when printing a document, when the print commandis invoked by the system or the application, the print data is sent to the buffer andis then transferred to the printer. From there, the printer accesses the information.This frees the computer up to do other tasks while the print command is beingperformed.

One disadvantage to this system is that any data in the buffer during devicefailure is lost. A buffer is a data area shared by hardware devices or programprocesses that operate at different speeds or with different sets of priorities. Thebuffer allows each device or process to operate without being held up by the other.

In order for a buffer to be effective, the size of the buffer and the algorithmsfor moving data into and out of the buffer need to be considered by the bufferdesigner. Like, a buffer is a "midpoint holding place" but exists not so much toaccelerate the speed of an activity as to support the coordination of separateactivities.

28

This term is used botbuffering sometimes impliesso that it can be edited or othor database.

Intention of a buffer

The purpose of mosmanipulate before transferriand data too are relatively slthen the buffer to a disk. Ththe disk file with the content

This is much more effitime you make a change to ta buffer, not on the disk, all o

28

oth in programming and in hardware. In lies the need to screen data from its final i

r otherwise processed before being moved to

ost buffers is to act as a holding areaferring it to the main memory. Because

slow, many keep track of data changes inThen when you save the file, the word procents of the buffer.

efficient than accessing the file on the disto the file. Note that because your changes ll of them will be lost if it fails during an ed

28

In programming,l intended place to a regular file

rea, enabling touse the processs in a buffer androcessor updates

disk where eaches are initially in editing session.

29

1

Even with a world fuand car audio systems that pCDs. In addition to playing,audio and video formats, Remedia. This is a necessary feCDs. Maybe your home ent

inputs for digital media, butcar doesn’t have a USB slot

Or maybe you want to burnlisten to the CD without ruin

Before you can burn a CD:

First, make sure yCD-R (Compact Ddiscs. All modern Second, have a suCD-R. They are m

need the complexiThird, insert a disc

29

15. BURNING A DISC

full of iPods, MP3 players, digital home at play music from USB flash memory; peong, downloading and converting a wide vari RealPlayer can also record, or burn CD-R

ry feature for those who still want or need tntertainment system doesn’t have the lates

but there is a CD, DVD or Blue ray player.lot to plug in flash memory or an iPod, only

urn music to a blank CD, so you can let uining the original.

D:

re your computer is connected to a drive tht Disc-Record) or CD-RW (Compact Discrn disc drives will read and write both CDs supply of blank CD-R or CD-RW discs. I

re more reliable for playing. Just starting o

exity of Re-Writable. Use quality, brand namisc in the CD/DVD drive.

29

e media serverspeople still burnvariety of digital-R and CD-RWd their music ontest and greatest

yer. Maybe yournly a CD player.

let your children

that can recordisc-Re Writable)

CDs and DVDs.. I suggest usingg out, you don’t

name discs.

30

How Long Will Auto M anufacturers Include CD Players in Cars? Here’s a

Guess.

The death of the factory in-dash cassette player was a long one. Delco andMotorola units first started appearing in new models in about 1970. The last newmodel car to come with a factory cassette player was the 2010 Lexus SC430. Formost of that time, the in-dash cassette player co-existed with the factory CD player,which was first included in the 1984 S-Class Mercedes. But ever since the cassetteplayer disappeared from new models, so has the CD playeras more and morepeople prefer to plug their smart phones than lug around stacks of compact discs. Itwasn’t that long ago that many of us spent hours burning mix CDs just for the car.

My limit was six–maybe 75 songs–because I had a six-pack changer and onceloaded, I rarely bothered to swap out an old disc for a new one.

According to a survey of automotive experts, the factory CD player shouldbe gone by 2019. That’s just three years away. If you’re shopping for a new, you

may have encountered CD players as options. Some models–especially thoseaimed at Millennial–don’t even offer a CD player because market research shows

that the majority of buyers for those vehicles will never use it.

Term Description

CD-R CD-Recordable. Write Once, Read Many. (WORM)

CD-RW CD-Rewritable. Write Many, Read Many.

ISO-9660DOS compatible file system (8.3 character file names) for CD's.Requires extensions like "Rock Ridge" to fully support UNIX/Linux

Rock RidgeISO-9660 extension to allow long file names, UNIX symlinks and fileprotection (rwx). Windows readable.

JolietMicrosoft extension to ISO-9660. Creates MS/Windows 95 like 8.3 filenames with translation to 64 character names.

MultisessionAllows adding/writing files at a later time. Session must be closedbefore it is readable.

DAOBurn entire audio CD at once in a single burn. It's the only way to avoiddelays between tracks

31

What is CAPTCHA?

Well, since you askestands for "CompletelyAutoTuring test to tellComputersApart". Since the dawn of people have tried to abuseboth sport and profit. As theprofitable, the scale of abuautomated software (sometimas bots). To prevent botregistrations, fake sweepstaresponded by testing users to

Applications of CAPTCHA

CAPTCHAs have several alimited to:

Preventing Comment programs that submitsearch engine ranks of called comment spamcomments on a blog. enter a comment, and Protecting Website services. Up until a fespecific type of attacaccounts every minuteto ensure that only hushould be protected automated scripts.Protecting Email Addraddresses posted in cl

31

16. CAPTCHA

ked, CAPTCHAutomatedPublicters andHumans of the Internet,use websites forthe abuse becamebuse grew usingtimes referred to

bots from overrunning sites with spamstakes entries, and other nefarious thing

rs to see if they were human or not.

HA

l applications for practical security, inclu

ent Spam in Blogs- Most bloggers are it bogus comments, usually for the purp

of some website (e.g., "buy penny stocks hpam. By using a CAPTCHA, only humag. There is no need to make users sign u

nd no legitimate comments are ever lost!te Registration- Several companies offea few years ago, most of these services sutack: "bots" that would sign up for thousaute. The solution to this problem was to use humans obtain free accounts. In general,ed with a CAPTCHA in order to prev

Addresses From scrapers- The Web in se clear text. CAPTCHAs provide an effectiv

31

pam, fraudulentings, publishers

cluding but not

re familiar withrpose of raising

ks here"). This ismans can enter up before they

ffer free email suffered from ausands of emailuse CAPTCHAsral, free servicesrevent abuse by

search of emailctive mechanism

32

to hide your email address from Web scrapers. The idea is to require users tosolve a CAPTCHA before showing your email address. A free and secureimplementation that uses CAPTCHAs to obfuscate an email address can befound atOnline Polls- In November 1999, http://www.slashdot.org released anonline poll asking which was the best graduate school in computer scienceAs is the case with most online polls, IP addresses of voters were recorded inorder to prevent single users from voting more than once. However, studentsat Carnegie Mellon found a way to stuff the ballots using programs thatvoted for CMU thousands of times. CMU's score started growing rapidly.

The next day, students at MIT wrote their own program and the pollbecame a contest between voting "bots." MIT finished with 21,156 votes,Carnegie Mellon with 21,032 and every other school with less than 1,000.Can the result of any online poll be trusted? Not unless the poll ensures thatonly humans can vote.

Preventing Dictionary Attacks- CAPTCHAs can also be used to preventdictionary attacks in password systems. The idea is simple: prevent acomputer from being able to iterate through the entire space of passwords byrequiring it to solve a CAPTCHA after a certain number of unsuccessfullogins. This is better than the classic approach of locking an account after asequence of unsuccessful logins, since doing so allows an attacker to lockaccounts at will.Search Engine Bots- It is sometimes desirable to keep web pagesunindexed to prevent others from finding them easily. There is an html tag toprevent search engine bots from reading web pages. The tag, however,doesn't guarantee that bots won't read a web page; it only serves to say "nobots, please." Search engine bots, since they usually belong to largecompanies, respect web pages that don't want to allow them in. However, inorder to truly guarantee that bots won't enter a web site, CAPTCHAs areneeded.Worms and Spam- CAPTCHAs also offer a plausible solution againstemail worms and spam: "I will only accept an email if I know there is ahuman behind the other computer." A few companies are already marketingthis idea.

33

1

Definition

Cache memory also ccomputer can access moretypically integrated directlyconnect with the CPU.

Cache memory levels expla

Cache memory is fas"levels" that describe its clos

Level (L1) cache is embedded in the proceLevel 2 (L2) cacheisthe CPU or on a sepainterconnecting the cathe main system bus.

33

17. CACHE MEMORY

o called CPU memory is random access mre quickly than it can access regular RAtly with chip or placed on a separate tha

plained

fast and expensive. Traditionally, it is closeness and accessibility to the microproce

is extremely fast but relatively small, arocessor chip (CPU).he is often more capacious than L1; it may

parate chip or with a high-speed alternativ cache to the CPU, so as not to be sloweds.

33

s memory that ar RAM. This isthat has a inter

s categorized asrocessor:

, and is usually

ay be located onative system bused by traffic on

34

Level 3 (L3) cacheisthe performance of L1but is usually double t

Specialized caches

In addition to instructiprovide specialized functionspecialized cache because instruction caching from caching, referring to each specialized cache.

Other specialized mecaches include the transllook side buffer) whose funis to record to translations.

Still other caches aretechnically speaking, mecaches at all. For example, leverage RAM or to promuch the same kind of caching as memory cachewith CPU instructions. If dafrequently accessed from diis cached into or flash-based

Increasing cache size

L1, L2 and L3 caccombination of processor anthree levels of memory cacmeans for increasing cachespecific motherboard with dwith the right amount of inte

34

he is typically specialized memory that worf L1 and L2. It can be significantly slower tle the speed of RAM.

ction and data caches, there are other cacheions in a system. By some definitions, the se of its shared design. Other definitm datach as a

memorynslationfunction.

are not,memoryle, mayprovideof datahes do data is disk, ited storage technology for faster access and

caches have been implemented in the r and recently, the trend has been toward con

aching on the CPU itself. For this reasonche size has begun to shift from the acq different and bus architectures to buying

ntegrated L1, L2 and L3 cache.

34

orks to improver than L1 or L2,

ches designed tohe L3 cache is anitions separate

nd response.

e past using aconsolidating allson, the primaryacquisition of ag the right CPU

35

18. COMPUTER AIDED DESIGN (CAD)

Definition

CAD (computer-aided design) software is used by architects, engineers,drafters, artists, and others to create precision drawings or technical illustrations.CAD software can be used to create two-dimensional (2-D) drawings or three-dimensional (3-D) models.

Computer-aided design/computer-aided manufacturing is software used todesign products such as electronic circuit boards in computers and other devices.

Computer-Aided Design is a leading international journal that providesacademia and industry with key papers on research and developments in theapplication of computers to design.

Computer-Aided Design is a leading international journal that providesacademia and industry with key papers on research and developments in theapplication of computers to design.

Computer-Aided Design invites papers reporting new research, as well asnovel or particularly significant applications, within a wide range of topics,spanning all stages of design process from concept creation to manufacture andbeyond. Examples of relevant topics include but are not limited to:

Why CAD Software?

This technology makes product design more efficient by automatingprocesses that were once manual, such as traditional drafting. With 3D CAD,designers can also do solid modeling, creating three-dimensional representations oftheir products.

But CAD isn't just about convenience or bells and whistles.

Broadly speaking, CAD software helps you explore concept design ideas,create product designs, carry out simulations and analyses, and performengineering calculations. In other words, CAD tools assist you with the

36

experimentation, exploratiteration needed to make thyour design's potential. searching goal? better produced more efficiently acost so that you get your pmarket faster.

We’re proud of the

PTC invented and first parametric CAD modelingnearly 30 years ago. Todadevelopment professionals use our flagship CAD softwa

CAD is used as follows:

1. To produce detailed ethe physical componen

2. To create conceptual of assembly and the m

3. To prepare environmeare used in photograpnew structures are bui

CAD systems exist todWindows, Linux and Maccomputer mouse, but a pe

Most U.S. universities using protractors and compaof CAD software. Becauuniversities and manufacturetools. These tools have alsefficient, lowering these train

36

ration, and the most of. The overer productsy and at lessr products to

the fact that

st launcheding softwareday, productls worldwidetware suite.

d engineering designs through 3-D and 2-Dnents of manufactured products.al design, product layout, strength and dyn manufacturing processes themselves.mental impact reports, in which computer-raphs to produce a rendering of the appearauilt.

today for all of the major computer platformac OS X. The user interface generally pen and digitizing graphic tablet can a

es no longer require classes for producing hpasses. Instead, there are many classes on dause hardware and software costs areturers now train students how to use thealso modified design work flows to makraining costs even further.

36

2-D drawings of

ynamic analysis

ter-aided designsarance when the

forms, includingly centers on an also be used.

g hand drawingsn different typesare decreasing,these high-levelake them more

37

19. CHARG

Definition

A charge-coupled devstores and displays the data foin the image is converted intto a color in the color spectrube a separate value for each commonly included in digiastronomical telescopes, scain for robots, in optical photographs, and in the enha

Architecture

The CCD image sarchitectures. The most comfull-frame, frame-transfer, aof these architectures

In a full-frame devicelectronic shutter. A mechanimage smears as the device i

37

RGE COUPLED DEVICE (CCD)

device (CCD) is a light-sensitive integrateta for an image in such a way that each (pic into an electrical charge the intensity of wctrum. For a system supporting 65,535 colch color that can be stored and recovered. CCDigital still and video cameras. They are

scanners, and readers. The devices have aal character recognition (OCR), in the hancement of images, especially in meteor

sensors can be implemented in sevemmon is their approach to the problem of s

r, and interline. The distinguishing characte

vice, all of the image area is active, ananical shutter must be added to this type of e is clocked or read out.

37

)

rated circuit that(picture element)f which is relatedcolors, there will. CCDs are nowre also used ine also found usee processing ofeorology.

everal differentof shuttering. arecteristic of each

and there is no of sensor or the

38

With a frame-transfer mask (typically aluminum). area to the opaque area or sThat image can then be readis integrating or exposing innot require a mechanical shustate broadcast cameras. Therequires twice the silicon recosts roughly twice as much.

CDs containing gridsdevices. Most common typeallows devices, and zero videtectors, the sensitivity is li

One other consequencoften appears on CCD-baseinfrared blockers.

Cooling reduces the alight intensities, even for observatories often cool ththerefore to negligible levels

38

fer CCD, half of the silicon area is covered). The image can be quickly transferred fr

r storage region with acceptable smear of aad out slowly from the storage region while in the active area. Frame-transfer deviceshutter and were a common architecture fo

The downside to the frame-transfer archite real estate of an equivalent full-frame devch.

ids of are used in and video cameras asypes of CCDs are sensitive to near-infrared video-recording/photography For normal s limited to 1.1μ m.

ence of their sensitivity to infrared is that ased digital cameras or camcorders if they

e array's, improving the sensitivity of thefor ultraviolet and visible wavelengths. their detectors with to reduce the darkels.

38

ed by an opaque from the imagef a few percent.

hile a new imageices typically do

re for early solid-itecture is that itdevice; hence, it

as light-sensingred light, whichal silicon-based

at infrared fromhey do not have

the CCD to lowhs. Professionalark current, and

39

20. COMMON

Definition

The common gatewayWeb user's request to an appto the user. When the user highlighted word or enterinrequested page. However, win, it usually needs to be protypically passes the form infothe data and may send backfor passing data back and focommon gateway interface (

What Is CGI?

As you traverse the vacross documents that madocuments could consist of,registration information, imaimage, counters that displayutilities that allow you to cases, you'll find that theseInterface, commonly known

39

ON GATEWAY INTERFACE (CG

ay interface (CGI) is a standard way for a application program and to receive data baer requests a Web page (for example, by ering a Web site address), the server se

r, when a user fills out a form on a Web pag processed by an application program. Thinformation to a small application program ack a confirmation message. This method forth between the server and the applicatioe (CGI).

e vast frontier of the World Wide Web, ymake you wonder, "How did they do of, among other things, forms that ask fomage maps that allow you to click on variolay the number of users that accessed the do search databases for particular informaese effects were achieved using the Comm

n as CGI.

39

GI)

r a Web to pass a back to forwardby clicking on asends back theage and sends itThe Web serverm that processesd or conventiontion is called the

, you will comeo this?" These

for feedback orrious parts of thee document, and

rmation. In mostmmon Gateway

40

One of the Internet's wThat is, it's trivial in design,can write rudimentary scripdemanding that you have toway, CGI is easy the samepoach an egg.

CGI Applications

CGI turns the Web from a siwhole new interactive meapplications. Let's take a lodesigned using CGI.

Generally, forms are can be used to collect informmore complex manner to procan be presented with a formas well as an option to searchCGI program can process thuser's selection criteria.

40

t's worst-kept secrets is that CGI is astoundgn, and anyone with an iota of programmicripts that work. It's only when your ne to master the more complex workings of me way cooking is easy: anyone can toas

simple collection of static hypermedia docmedium, in which users can ask quest look at some of the possible application

re used for two main purposes. At their siformation from the user. But they can alsoprovide back-and-forth interaction. For exarm listing the various documents available rch for particular information within these this information and return document(s) t

40

undingly simple.ming experienceneeds are moreof the Web. In aoast a muffin or

documents into aestions and runions that can be

r simplest, formslso be used in axample, the userle on the server,se documents. As) that match the

41

21. CHIP SET

Introduction

A chipset is a group of integrated circuits (microchips) that can be usedtogether to serve a single function and are therefore manufactured and sold as aunit. For example, one chipset might combine all the microchips needed to serve asthe communications controller between a processor and memory and other devicesin a compute.

In a computer system, a chipset is a set of electronic components inan integrated circuit that manages the data flow betweenthe processor, memory and peripherals. It is usually found on the motherboard.Chipsets are usually designed to work with a specific family of microprocessors.Because it controls communications between the processor and external devices,the chipset plays a crucial role in determining system performance.

Intel ICH7 Southbridge on Intel D945GCPE Desktop Board

Computer

In computing, the term Chipset commonly refers to a set ofspecialized chips on a computer's motherboard or an expansion card. In personalcomputers, the first chipset for the IBM PC AT of 1984 was the NEATchipset developed by Chip sandChipSandTechnologies for the INEL80286 CPUTechnologies for the Intel80286 CPU.

Move towards Processor Integration In Pcs

Traditionally in x86 computers, the processor's primary connection to therest of the machine is through the motherboard chipset's north bridge. The northbridge is directly responsible for communications with high-speed devices (systemmemory and primary expansion buses, such as PCI e, AGP and PCI cards, being

42

common examples) and cprocessor. This connection bknown as the front side bus (

Requests to resourceoffloaded to the south bridgethe processor and the sou"everything else", generallylargest being hard disk and communications. The connenot have a common name, bthe chipset

The Best Chip Set Manufac

A list of top chipsare best companies in their fipurchase the chipset then thbrands we are looking it to pthese are the companies andlooking at. As easy as buyincan be, there is a definite swith building our own PC.monitor, keyboard, mouse, aour desk. The computer itsesound card, network card, poto put it all in.

Some Mother board maintegrated. If we are carefumachine for less money thatour hardware, we can also se

42

conversely any system communication n between the processor and North Bridge is (FSB).

rces not directly controlled by the nortdge, with the north bridge being an intermesouth bridge. The south bridge traditio

rally lower-speed peripherals and board fud storage connectivity) such as USB, paranection between the north bridge and sout

e, but is usually a high-speed interconnect

nufacures

ipset manufactures. theseir field . If we are looking these the companies andto purchase a chipset thenand brands we should beying a prebuilt computere satisfaction that comesPC. Beyond the obviouse, and speakers that sit ontself requires a CPU, motherboard, RAM, , power supply, hard disk drive, power supp

may also have those separate expansion reful, we may even be able to build our hat it would cost for a pre-built model. Whe sell the individual components to help offs

42

on back to thee is traditionally

orth bridge arermediary betweentionally handles

rd functions (thearallel and serialouth bridge doesct proprietary to

, graphics card,pply, and a case

n cards alreadyour own customhen we upgrade

ffset our costs.

43

22. CHARACTER LARGE OBJECT (CLOB)

A Character Large Object (or CLOB ) is a collection of character datastored in a database usually stored in a separate location that is referenced in thetable itself. Database provide a construct explicitly named CLOB, and the majorityof other database systems support some form of the concept, often labeled as text,memo or long character fields. Lobs usually have very high size-limits, of the orderof 2GB or more.

How to Dataset with Sql Server?

The Dataset contains the copy of the data we requested through the SQLstatement. We can use Dataset in combination with SqlDataAdapter class . TheSqlDataAdapter object allows us to populate in a Dataset. We can use Fill methodin the SqlDataAdapter for populating data in a Dataset.

Search Tables in a Dataset Sql Server

The DataSet contains DataTableCollection and their DataRelationCollection.The DataTableCollection contains zero or more objects. The Dataset maycomprise data for one or more members, corresponding to the number of rows. TheSqlDataAdapter object allows us to populate DataTables in a DataSet.

44

CLOB Data Type - Conversion Details

In Oracle, you can specify a string literal in SQL INSERT statement to insertdata into a CLOB column. You can also insert an empty value usingEMPTY_CLOB() function, and you can insert NULL.

BLOBs and CLOBs

Caché SQL supports the ability to storeBLOBs (Binary Large Objects) and CLOBs(Character Large Objects) within the database.BLOBs are used to store binary information,such as images, while CLOBs are used to storecharacter information.

BLOBs and CLOBs can store up to 4Gigabytes of data (the limit imposed by theJDBC and ODBC specifications).

The operation of the Blobs and CLOBsis identical in every respect except how theyhandle character encoding conversion (such as Unicode to multiyear) whenaccessed.

Overview of CLOB

CLOB (Character Large Object) is a large collection of character data stored ina database table. Different database servers handles CLOB differently. But thereare some common characteristics like:

CLOB stores character data, which requires a specific encoding schema. Forregular ASCII characters, the database default encoding schema is fine. Soyou don't need to worry.CLOB data is usually large. Many database servers offer very highmaximum sizes like 4 GB.Operations on CLOB data is usually restricted. For example, LIKE may notbe used on CLOB data.CLOB data is usually not directly stored inside the table. It is stored indifferent storage areas and its reference address is stored inside the table.

45

23. CLOCK CYCLE

DefinitionThe speed of a computer processor, or CPU, is determined by the clock

cycle, which is the amount of time between two pulses of an oscillator. Generallyspeaking, the higher number of pulses per second, the faster the computerprocessor will be able to process information. The clock speed is measured in Hz,typically either megahertz (MHz) or gigahertz (GHz).

For example, a 4GHz processor performs 4,000,000,000 clock cycles persecond. Computer processors can execute one or more instructions per clock cycle,depending on the type of processor. Early computer processors and slowerprocessors can only execute one instruction per clock cycle, but faster, moreadvanced processors can execute multiple instructions per clock cycle, processingdata more efficiently.

Machine CycleThe steps performed by the computer processor for each machine language

instruction received. The machine cycle is a 4 process cycle that includes readingand interpreting the machine language, executing the code and then storing thatcode.

Instruction CycleAn instruction cycle (sometimes called fetch-decode-execute cycle) is the

basic operation cycle of a computer. It is the process by which a computer retrievesa from its determines what actions the instruction requires, and carries out thoseactions. This cycle is repeated continuously by the CPU, from to when thecomputer is shut down.

46

In simpler CPUs, the instruction cycle is executed sequentially: eachinstruction is completely processed before the next one is started. In most modernCPUs, the instruction cycle is instead executed in, as: the next instruction startsbeing processed before the previous instruction is finished, which is possiblebecause the cycle is broken up into separate steps.

Clock Speed

It is also called clock rate, the speed at which. Every machine contains aninternal clock that regulates the rate at which instructions are executed andsynchronizes all the various computer components. It requires a fixed number of(or clock cycles) to execute each instruction. The faster the clock, the moreinstructions the CPU can execute per second. Clock speeds are expressed inmegahertz or gigahertz.

The internal of a CPU has as much to do with a CPU's performance as theclock speed, so two CPUs with the same clock speed will not necessarily performequally.

Whereas an Intel 80286 microprocessor requires 20 cycles to multiply twonumbers, an Intel 80486 or later can perform the same calculation in a single clocktick. (Note that clock tick here refers to the system's clock, which runs at 66 MHzfor all PCs.) These newer processors, therefore, would be 20 times faster than theolder processors even if their clock speeds were the same. In addition, somemicroprocessors are which means that they can execute more than one instructionper clock cycle.

47

24. CLONE SOFTWAREDefinition of Cloning Software

Clone Software that copies the entire hard disk to another hard disk or toanother computer via direct cable or the network. Cloning is used to back up thecomputer for a future system restore and to provide to interim storage for replacingthe hard disk.

Drive Copy

Advantages:

It’s also used to make a master copy of computer configuration for quick

installations on new machines.The cloned disk is copied verbatim (cloned again) to the new computermuch quicker than installing the OS and applications individually.See image file, reimaging, hosting server and clone. Clone is an easy to usefile backup utility. “Clone software – fast, easy, full hard disk backupsoftware”.

48

Clone can be configured to carry out auto mated backups of our critical data.Once we have configured clone we need to take no further action to ensureall our important data is backed up.

How it works?

Main features backup files and directories to a defined location-as many aswe like use the data and time, file size or archive attribute to determine if a fileshould be copied synchronize directories Run as a standard windows utility or as ascreen saver mode we can run our favorite screen saver as will backup to anymedia (including CD-RAW) that can be mapped to windows drive or UNC pathuse file filters to specify the type of the files we want to copy.

Working plan

Clone does not use any proprietary format for storing our files, we won’t

even need a copy of clone to restore our files, and windows explorer will do thejob.

It’s all carried out automatically. Clone copies files from one location to

another. Our file are copied “as is” making it very simple to recover after an

unforeseen loss of data.

Common uses

Reboot and restoreProvisioning new computerHard drive upgradeFull system backupSystem recoveryTransfer to another user

49

25. CLOUD COMPUTING

Origin of the term

The origin of the term cloud computing is unclear. The word "cloud" iscommonly used in science to describe a large agglomeration of objects thatvisually appear from a distance as a cloud and describes any set of things whosedetails are not inspected further in a given context. Another explanation is that theold programs that drew network schematics surrounded the icons for servers with acircle, and a cluster of servers in a network diagram had several overlappingcircles, which resembled a cloud.

Similar Concepts

Cloud computing is the result of the evolution and adoption of existingtechnologies and paradigms. The goal of cloud computing is to allow users to takebeneath from all of these technologies, without the need for deep knowledge aboutor expertise with each one of them. The cloud aims to cut costs, and helps the usersfocus on their core business instead of being impeded by IT obstacles.

Characteristics

Cloud computing shares characteristics with:

Client–server model— Client–server computing refers broadly to anydistributed application that distinguishes between service providers (servers)and service requestors (clients).

50

Grid computing — "A form of distributed and parallel computing, wherebya 'super and virtual computer' is composed of a cluster of networked, looselycoupled computers acting in concert to perform very large tasks."Mainframe computer — Powerful computers used mainly by largeorganizations for critical applications, typically bulk data processing such as:census; industry and consumer statistics; police and secret intelligenceservices; enterprise resource planning; and financial transaction processing.Utility computing — The "packaging of computing resources, such ascomputation and storage, as a metered service similar to a traditional publicutility, such as electricity."Peer-to-Peer— A distributed architecture without the need for centralcoordination. Participants are both suppliers and consumers of resources (incontrast to the traditional client–server model).

Infrastructure As A Service (IAAS)

In the most basic cloud-servicemodel - and according to the IETF(Internet Engineering Task Force) -providers of Bias offer computers–

physical or (more often) virtualmachines– and other resources. Iasirefers to online services that abstractuser from the detail of infrastructurelike physical computing resources,location, data partitioning, scaling,security, backup etc.

Cloud Clients

User’s access cloud computing using networked client devices, such as

desktop computers, laptops, tablets and smart phones and any Ethernet enableddevice such as Home Automation Gadgets. Some of these devices– cloud clients–rely on cloud computing for all or a majority of their applications so as to beessentially useless without it.

51

A cluster is a group of seand enable high availabilitprocessing.

In personal computer stostorage on a hard disk; it's mstored on a hard disk takes ube scattered among differenwith a file are kept track of in

Size of Cluster

The maximum numbeFAT table entry. Beginning allowing for a maximum of 6

The tradeoff in cluster itself) takes up the entire clthat's the cluster size. In fact4,096 or 8,192 bytes. Largereach with a FAT capable of s

51

26. CLUSTER

f servers and other resources that act like a ility and, in some cases, load balancing

storage technology, a cluster is the logica's managed by the computer's operating syss up one or more clusters of storage. A filerent locations on the hard disk. The clustf in the hard disk's file allocation table (FAT

ber of clusters on a hard disk depends onng with DOS 4.0, the FAT entries were 16 of 65,536 clusters.

ter size is that even the smallest file (and ev cluster. Thus, a 10-byte file will take up

fact, many operating systems set the cluster rger hard disks could be divided into up to foof supporting 512 megabytes of clusters.

51

a single systeming and parallel

ical unit of filesystem. Any filefile's clusters canusters associatedFAT).

on the size of a16 bits in length,

even a directoryp 2,048 bytes ifer size default ato four partitions,

52

Server ClusterA server cluster is a g

single system to provide higoccurs on one computer in aredistributed to another comensure that users have constaclusters are designed for appfrequently updated data. Typservers, database servers, and

Master Cluster

Master-cluster is a implementing node.js core cluproject. Also provides hot reloworker in development moderestarted when code is changed

Cluster SlavesThe command provid

master node.Note that if a slave is

and we ask to a node that hshow stale information. Hownetwork partitions) all the nogiven master.

Cluster Replicate

The command reconfinode receiving the commanmaster to slave.

Once a node is turnedto inform the other cluster nbetween nodes will propagat

52

a group of independent servers and workinghigh availability of services for clients. Wn a cluster, resources are redirected and thomputer in the cluster. You can use servstant access to important server-based resoapplications that have long-running in-meypical uses for server clusters include filend messaging servers.

a utility to facilitatecluster module in anyeloading of files on thede so that workers areged.

ides a list of slave nodes replicating from

is added, moved, or removed from a givent has not yet received the configuration uowever eventually (in a matter of seconds i nodes will agree about the set of nodes ass

nfigures a node as a slave of the specified and is an empty master, the node role is

ed into the slave of another master node, ther nodes about the change: heartbeat packegate the new configuration automatically.

52

ing together as a. When a failure the workload iserver clusters toresources. Servermemory state orfile servers, print

om the specified

ven master node,n update, it mays if there are no

associated with a

ed master. If theis changed from

, there is no needckets exchanged.

53

27. COMPUTER DAEMON

In computer a daemon or is that runs as a, rather than being under the directcontrol of an interactive user. Traditionally daemon names end with the letter d.For example, is the daemon that implements the system logging facility, and is adaemon that services incoming connections.

In a environment, the of a daemon is often, but not always, the process. Adaemon is usually either created by a process a child process and then immediatelyexiting, thus causing init to adopt the child process, or by the init process directlylaunching the daemon. In addition, a daemon launched by forking and exitingtypically must perform other operations, such as dissociating the process from anycontrolling. Such procedures are often implemented in various convenienceroutines such as daemon in UNIX.

Systems often start daemons at time and serve the function of responding tonetwork requests, hardware activity, or other programs by performing some task.Daemons can also configure hardware like on some system, run scheduled taskslike, and perform a variety of other tasks.

Terminology

The term was coined by the programmers of. They took the name from, animaginary being from a thought experiment that constantly works in thebackground, sorting molecules. Systems inherited this terminology. Maxwell'sDemon is consistent with Greek mythology's interpretation of a as a supernaturalbeing working in the background, with no particular bias towards good or evil.However, and some of its derivatives have adopted a as their rather than a Greekdaemon. The word daemon is an alternative spelling of demon, and is pronounced.In the context of computer software, the original pronunciation has drifted to forsome speakers.

Creation

In a strictly technical sense, a Unix-like system process is a daemon when itsparent process terminates and the daemon is assigned the process (process number1) as its parent process and has no controlling terminal. However, more commonly,

54

a daemon may be any background process, whether a child of the init process ornot.

On a Unix-like system, the common method for a process to become adaemon, when the process is started from the or from a startup script such as anscript or a script, involves:

• Dissociating from the controlling• Becoming a session leader• Becoming a leader• Executing as a by and (once or twice). This is required sometimes for the

process to become a session leader. It also allows the parent process tocontinue its normal execution.

• Setting the (/) as the current so that the process does not keep any directoryin use that may be on a mounted file system (allowing it to be unmounted).

• Changing the to 0 to allow open(), create(), and other operating system callsto provide their own permission masks and not to depend on the umask ofthe caller

• Closing all inherited files at the time of execution that are left open by theparent process, including 0, 1 and 2 for the (,and). Required files will beopened later.

• Using a, the, or asIf the process is started by a daemon, such or, the super-server daemon will

perform those functions for the process (except for old-style daemons notconverted to run under system and specified as Type=forkingand "multi-threaded"datagram servers under indented.

55

28. D

The data transfer rateinternal rate (moving data beand the external rate (movinsystem).

The measurable data tThe sustained data transfer raof the sustained internal and

The sustained rate ibecause it does not have theThe internal rate is further head switch time, and cylind

Media rateRate at which th

Sector overhead timeAdditional timeand other informvalidate data an

55

. DATA TRANSFER RATE

rate of a drive (also called throughput) co between the disk surface and the controller ing data between the controller on the driv

ta transfer rate will be the lower (slower) of r rate or sustained throughput of a drive wilnd sustained external rates.

e is less than or equal to the maximum the benefit of any cache or buffer memoryer determined by the media rate, sector oinder switch time. These are not applicable t

the drive can read bits from the surface of meme (bytes between sectors) needed for conformation necessary to manage the driv

and perform other support functions.

55

covers both theller on the drive)rive and the host

of the two rates.will be the lower

m or burst rateory in the drive.r overhead time,le to SSDs.

of the media.

ontrol structuresrive, locate and

56

Head switch timeAdditional time required to electrically switch from one head toanother and begin reading; only applies to multi-head drive and isabout 1 to 2 ms.

Cylinder switch timeAdditional time required to move to the first track of the next cylinderand begin reading; the name cylinder is used because typically all thetracks of a drive with more than one head or data surface are readbefore moving the actuator. This time is typically about twice thetrack-to-track seek time. As of 2001, it was about 2 to 3 ms.

As of 2010, a typical 7200 RPM desktop HDD has a "disk-to-buffer" datatransfer rate up to 1030 Mbit/s. This rate depends on the track location, so itwill be higher on the outer zones (where there are more data sectors pertrack) and lower on the inner zones (where there are fewer data sectors pertrack); and is generally somewhat higher for 10,000 RPM drives.Floppy disk drives have sustained "disk-to-buffer" data transfer rates that areone or two orders of magnitude lower than that of HDDs.The sustained "disk-to-buffer" data transfer rates varies amongst families ofOptical disk drives with the slowest 1x CDs at 1.23 Mbit/s floppy-like whilea high performance 12x Blue-ray disc drive at 432 Mbit/s approaches theperformance of HDDs.

Effect of file system

Transfer rate can be influenced by file system fragmentation and the layoutof the files. Defragmentation is a procedure used to minimize delay in retrievingdata by moving related items to physically proximate areas on the disk.

Effect of areal density

HDD data transfer rate depends upon the rotational speed of the disks andthe data recording density. Because heat and vibration limit rotational speed,increasing density has become the main method to improve sequential transferrates. Area l density (the number of bits that can be stored in a certain area of thedisk) has been increased over time by increasing both the number of tracks acrossthe disk, and the number of sectors per track.

57

Definition

In computer science anis a classification identifyingBoolean, that determines thebe done on values of that typtype can be stored.

Classes of data types

I. Primitive data typesMachine data types

All data in computers b(alternatives 0 and 1) on theusually a group of bits cainstructions is called a word(

Boolean type

The Boolean type reprevalues are possible, they aefficiency reasons. Many protype, instead interpreting (fo

Numeric types

Such as The integer daaccording to their ability to

57

29. DATA TYPE

e and computer programming, adata typeoing one of various types of data, such as rethe possible values for that type; the opera type; the meaning of the data; and the way

pess

rs based on digital electronics is represethe lowest level. The smallest addressable called a byte. The unit processed by mrd(as of 2011, typically 32 or 64 bits.

presents the values true and false. Althou are rarely implemented as a single bin

programming languages do not have an ex(for instance) 0 as false and other values as t

r data types, or "whole numbers". May to contain negative values (e.g. unsigned in

57

e or simplytypes real, integer orerations that canay values of that

resented as bitsle unit of data isy machine code

hough only twobinary digit for explicit booleanas true.

y be sub-typed in C and C++).

58

May also have a small number of predefined subtypes (such as short and long inC/C++); or allow users to freely define subranges such as 1..12

(e.g. Pascal/Ada).

Floating point data types, sometimes misleadingly called reals, containfractional values. They usually have predefined limits on both theirmaximum values and their precision. These are often represented as decimalnumbers.Fixed point data types are convenient for representing monetary values.They are often implemented internally as integers, leading to predefinedlimits.

II. Composite types

Composite types are derived from more than one primitive type. This can bedone in a number of ways. The ways they are combined are called data structures.Composing a primitive type into a compound type generally results in a new type,e.g. array-of-integer is a different type to integer.

III. Enumerations

The enumerated type. This has values which are different from each other, andwhich can be compared and assigned, but which do not necessarily have anyparticular concrete representation in the computer's memory; compilers andinterpreters can represent them arbitrarily. For example, the four suits in a deck ofplaying cards may be four enumerators named CLUB, DIAMOND,HEART,SPADE.

IV. Abstract data types

Any type that does not specify an implementation is an abstract data type.For instance, a stack can be implemented as an array memory containing , or asa linked list. Abstract types can be handled by code that does not know or "care"what underlying types are contained in them. Programming that is agnostic aboutconcrete data types is called generic programming.

59

30. DATA D

A data definition langdescription language (DDLsimilar to a computer planguage for defining daespecially database schemas.

A DDL is a langudefine data structures and For example, DDL commaused to add, remmodify tables within in a dconsidered a subset of SQLmay also define other types o

Four basic DDL commands

CREATEUSEALTERDROP

CREATE

Installing a database mancreate and manage many indsyntax, the CREATE commaand column definitions. The associated data type.

USEThe USE command al

within our DBMS. For exaand want to issue some comwould preface them

USE employe

59

DEFINITION LANGUAGE (DDL)

anguage or dataDL) is syntaxer programmingdata structures,as.

guage used tod modify data.mands can beremove, ora database. DDLs used in database app

SQL, the Structured Query Language. Howes of data, such as XML.

nds

anagement system(DBMS) on a computer independent databases. To build a new tabmand is used, followed by parameters for the DDL can also define the name of each co

allows us to specify the database we wishexample, if we're currently working in the commands that will affect the employeesm with the following SQL

oyees

59

L)

applications areowever, a DDL

ter allows us totable using SQLr the table name column and the

ish to work withe sales databasees database, weL command:

60

ALTEROnce we've created a

definition of it. The ALTER of a table w

DROPThe final command o

remove entire database objpermanently remove the pfollowingcommand:

Similarly, the command bedatabase:

Remember thatfrom your database. If we wcommand of the Data MLanguage in a nutshell.

ALTER TABLADD salary m

DROP TABL

DROP DATA

60

a table within a database, we may wish ER command allows us to make changes towithout deleting and recre

of the Data Definition Language, DROP,objects from our DBMS. For example, i personal_info table that we created,

below would be used to remove the enti

hat the DROP command removes entire de want to remove individual records, use Manipulation Language. That's the Da

ABLE personal_infory money null

BLE personal_info

TABASE employees

60

sh to modify thes to the structurecreating it.

ROP, allows us to, if we want to, we'd use the

ntire employees

re data structuresse the DELETEData Definition

61

31. DIAL-UP CONNECTION

Definition

A dial-up connection uses a standard phone line and analog modem toaccess the Internet at data transfer rates (DTR) of up to 56 Kbps. A dial-upconnection is a connection from an end user to an Internet service provider (ISP)that can be created over a conventional telephone line without any specialarrangement with the telecommunications carrier.

Dial-up Internet access is a form of Internet access thatuses the facilities ofthe public switched telephone network (PSTN) to establish a connection to anInternet service provider (ISP) by dialing a telephone number on a conventionaltelephone line.

Many remote areas depend on Internet dial-up connections becausebroadband and cable are rare in remote areas with low population numbers. ISPsoften provide free dial-up connections, a viable alternative for budget-conscioussubscribers.

Leased Line

A leased line is a private bidirectional or symmetric telecommunications linebetween two or more locations provided in exchange for a monthly rent.Sometimes known as a private circuit or data line in the UK.A leased line is adedicated, fixed-bandwidth, symmetric data connection.

A leased line is a telephone line that has been leased for private use. In somecontexts, it's called a dedicated line. A leased line is usually contrasted with aswitched line or dial-up line.

Used to provide point-to-point dedicated network connectivity.Analog leased line can provide maximum bandwidth of 9.6 Kbps.Digital leased lines can provide bandwidths :64 Kbps, 2 Mbps (E1), 8 Mbps (E2), 34 Mbps (E3) ...

62

ISDN

Integrated Services for standards for simultaneous dnetwork services over the tranetwork. ISDN supports data

Two types of user access are

Basic Access- Consis64Kbps user chanchannel) and one signally channel (D providing service at 14

Primary access - Cothirty 64Kbps user chchannels) and a 64 K2.048Mbps (One 6Synchronization).

Advantages

While the sound of a conanybody who had to use can't recognize it.High speed internet conndated and slower dial up cWe had a really quick diaa very slow one in the pasOne of the benefits of dianeed is a dial-up account the Internet.This can be useful if youspeed Internet services.

62

for Digital Network (ISDN) is a set of coms digital transmission of voice, video, data, traditional circuits of the public switched teata transfer rates of 64 Kbps (64,000 bits pe

are defined.

sists of twohannels (Be 16KbpsD channel)t 144 Kbps.

Consists ofchannels (B Kbps signally channel (D channel) provid 64 Kbps channel is used for F

onnecting modem is permanently etched inse a dial up connection, most children grow

nnections such as DSL,T1, and WiFi havep connections obsolete.dial up connection and I was really excited past.dial-up service is that if you have a land linnt and the modem built into your computer

ou are frequently in areas where you canno.

62

mmunicationta, and other telephone per second).

viding service atFraming and

into the brain ofrowing up today

ve made the out

ed because I had

line, all that youter to connect to

nnot access high

63

Definition

The graphical control (also called dialogue box osmall window that communithe user and prompts theDialog boxes are classifie"modeless", depending on winitiated the dialog. The typeuser interaction. The simplemessage and may require ausually by clicking "OK", proceed by clicking "OK""termination notice" sometimread in the event of either anof an application or the opeand must close.") Although tit is also criticized by usabiwhich is to protect against better alternatives exist.

Modeless

Non-modal or modeinformation is not essential twork continues elsewhere. Aeither separate from the mapplication, and items in thfunctions of the application. of this type where possible, of operation. An example me.g. the background and textwindow whatever color it is,

63

32. DIALOG BOX

rol element dialog boxx or just dialog) is aunicates information tothem for a response.ified as "modal" orn whether they block interaction with thepe of dialog box displayed is dependent upplest type of dialog box is the alert, whi

re an acknowledgment that the message h", or a decision as to whether or not an K" or "Cancel". Alerts are also used etimes requesting confirmation that the nor an intentional closing or unintentional cloperating system. (E.g., "Gedit has encounh this is a frequent interaction pattern for mability experts as being ineffective for its st errors caused by destructive actions, a

odeless dialog boxes are used when tal to continue, and so the window can be le

re. A type of modeless dialog box is a too main application, or may be detached fro the toolbar can be used to select certain. In general, good software design calls fo

le, since they do not force the user into a pa might be a dialog of settings for the curreext colors. The user can continue adding te is, but can change it at any time using the d

63

he software that upon the desired

hich displays a has been read,

an action shouldd to display a notice has beenclosing ("crash")untered an errorr modal dialogs,its intended use,, and for which

the requestede left open whiletoolbar which is from the mainrtain features or for dialogs to be particular mode

urrent document, text to the maine dialog.

64

Application modal

Modal dialog boxes temporarily halt the program: the user cannot continuewithout closing the dialog; the program may require some additional informationbefore it can continue, or may simply wish to confirm that the user wants toproceed with a potentially dangerous course of action (confirmation dialog box).Usability practitioners generally regard modal dialogs as bad design-solutions,since they are prone to produce mode errors. Dangerous actions should beundoable wherever possible; a modal alert dialog that appears unexpectedly orwhich is dismissed automatically (because the user has developed a habit) will notprotect from the dangerous action. A modal dialog interrupts the main workflow.This effect has either been sought by the developer because it focuses on thecompletion of the task at hand or rejected because it prevents the user fromchanging to a different task when needed.

Document modal

The concept of a document modal dialog has recently been used, mostnotably in OS X and Opera Browser. In the first case, they are shown as sheetsattached to a parent window. These dialogs block only that window until the userdismisses the dialog, permitting work in other windows to continue, even withinthe same application. In OS X, dialogs appear to emanate from a slot in their parentwindow, and are shown with a reinforcing animation. This helps to let the userunderstand that the dialog is attached to the parent window, not just shown in frontof it.

Both mechanisms have shortcomings

The Windows dialog box locks the parent window which can hide otherwindows the user may need to refer to while interacting with the dialog,though this may be mitigated since other windows are available through thetask bar.The OS X dialog box blocks the parent window, preventing the user fromreferring to it while interacting with the dialog. This may require the user toclose the dialog to access the necessary information, and then re-open thedialog box to continue.

65

3

History

In 1988, Shafi Goldwfirst to rigorously define thThey described a hierarchypresented the GMR signatueven an existential forgery ag

Definition

A digital signatureauthenticity of a digital mesrecipient reason to believe tthe sender cannot deny hrepudiation), and that the msignatures are commonly usein other cases where it is imp

Working

To create RSA signamodulusN that is the producthat e d ≡ 1 (mod φ (N)), whe

consists ofN ande, and the s

To sign a messagem,receiver checks that σ

e≡ m

prevent attacks, one can firstand then apply the RSA algobe proven secure in the soschemes were of a similar t

65

33. DIGITAL SIGNATURE

ldwasser, Silvio Micali, and Ronald Rives the security requirements of digital signa

rchy of attack models for signature schemature scheme, the first that could be prov against a chosen message attack.

re is a mathematical scheme for demoessage or documents. A valid digital sign

e that the message was created by a know having sent the message (authenticati

e message was not altered in transit (inteused for software distribution, financial tramportant to detect forgery or tampering.

gnature keys, generate an RSA key pair uct of two large primes, along with integershere φ is the Euler phi-function. The signee signer's secret key containsd.

m, the signer computesσ ≡ md (mod N). m (mod N). This basic scheme is not ve

irst apply a cryptographic hash function to tlgorithm described above to the result. This

so-called random oracle model. Most ear type: they involve the use of a trapdoor

65

vest became thenature schemes.

hemes, and alsoroved to prevent

monstrating theignature gives aown sender, thatation and non-ntegrity). Digitaltransactions, and

air containing agerse andd suchgner's public key

). To verify, the very secure. Too the message mhis approach can early signatureoor permutation,

66

such as the RSA function, or in the case of the Rabin signature scheme, computingsquare modulo compositen. A trapdoor permutation family is a family ofpermutations, specified by a parameter.

That is easy to compute in the forward direction, but is difficult to computein the reverse direction without already knowing the private key ("trapdoor").Trapdoor permutations can be used for digital signature schemes, where computingthe reverse direction with the secret key is required for signing, and computing theforward direction is used to verify signatures.

Applications of Digital Signatures

As organizations move away from paper documents with ink signatures orauthenticity stamps, digital signatures can provide added assurances of theevidence to provenance, identity, and status of an electronic document as well asacknowledging informed consent and approval by a signatory. The United StatesGovernment Printing Office (GPO) publishes electronic versions of the budget,public and private laws, and congressional bills with digital signatures.Universities including Penn State, University of Chicago, and Stanford arepublishing electronic student transcripts with digital signatures.

Authentication

Although messages may often include information about the entity sending amessage, that information may not be accurate. Digital signatures can be used toauthenticate the source of messages. When ownership of a digital signature secretkey is bound to a specific user, a valid signature shows that the message was sentby that user. The importance of high confidence in sender authenticity isespecially obvious in a financial context.

Integrity

In many scenarios, the sender and receiver of a message may have a need forconfidence that the message has not been altered during transmission. Althoughencryption hides the contents of a message, it may be possible to change anencrypted message without understanding it.

67

Definition

Direct3D is a grapMicrosoft Windows. Directapplication where performhardware acceleration if it iacceleration of the entire 3DDirect3D exposes the advaincluding Z-buffering,W-bu

Features in Direct 3d

Video mapping, hardwEven sprites providingties.Direct3D has supersed

Direct3D offers full emulation for features notprogrammed using Direct3Duser’s computer does not sup

Types of Devices:

There are four types of devic

67

34. DIRECT 3D

raphics application programming interfacrect3D is used to render three-dimensionarmance is important such as games. Dit is available on the graphics card allowing 3D rendering pipeline or even only partiavanced graphics capabilities of 3D graphbuffering.Stencil buffering.

rdware 3D rendering in 2D OVERLAV PLAing the use of 2D and 3D graphics in inte

seded the DIRECT DRAW FRAMEWORK

full vertex software emulation but no pnot available in hardware. For examplet3D requires pixel shaders and the video support that feature.

vices. They are:

67

rface (API) foronal graphics in

Direct3D usesing for hardwaretial acceleration.phics hardware,

PLANESnteractive media

RK.

pixel softwareple, if softwareeo card on the

68

HAL(Hardware Abstraction layer) device: For devices supportinghardware acceleration.Reference device:Simulates new functions not yet available in hardware. Itis necessary to install the Direct3D SDK to use this device type.Null reference device:Does nothing. This device is used when the SDK isnot installed and a reference device is requested.Pluggable software device:Performs software rendering. This device wasintroduced with DirectX 9.0

Moreover, devices contain a collection of resources; specific data usedduring rendering. Each resource has four attributes:

Type

Determines the type of resource: surface, volume, texture, cube texture,volume texture, surface texture, index buffer or vertex buffer.

POOL

Describes how the resource is managed by the runtime and where it isstored. In the Default pool the resource will exist only in device memory.Resources in the managed pool will be stored in system memory, and will be sentto the device when required. Resources in system memorypool will only exist insystem memory.

Format

Describes the layout of the resource data in memory. For example,D3DFMT_R8G8B8 format value means a 24 bits colourdepth (8 bits for red, 8bits for green and 8 bits for blue).

Usage

Describes, with a collection offlag bits, how the resource will be used by theapplication. These flags dictate which resources are used in dynamic or staticaccess patterns. Static resource values don’t change after being loaded, whereas

dynamic resource values may be modified.

69

35. DIR

Definition

Direct memory acceis a feature of computer syallows certain hardware subaccess main system memoindependently of the centralunit (CPU).

Without DMA, whentypically fully occupied for tthus unavailable to performtransfer, then it does other opreceives an interrupt from thfeature is useful at any timetransfer, or when the CPUrelatively slow I/O data trans

Many hardware sysgraphics cards, network cardata transfer in multi-core transfer data to and from dewithout DMA channels. DMor moving of data withinoperations, such as large codedicated DMA engine. ATechnology.

Modes of operation

• Burst mode

An entire block of datDMA controller is granted bytes of data in the data bloc

69

IRECT MEMORY ACCESS (DMA

ccess (DMA )r systems thatsubsystems tomory (RAM)

tral processing

hen the CPU is using programmed inpur the entire duration of the read or write oprm other work. With DMA, the CPU firsr operations while the transfer is in progress the DMA controller when the operation

ime that the CPU cannot keep up with thCPU needs to perform useful work while

ansfer.

systems use DMA, including disk drivcards and sound cards.DMA is also used re processors. Computers that have DMA devices with much less CPU overhead thMA can also be used for "memory to mem

thin memory. DMA can offload expen copies or scatter-gather operations, from An implementation example is the I/O

data is transferred in one contiguous sequed access to the system bus by the CPU, ilock before releasing control of the system

69

A)

put/output, it is operation, and isfirst initiates theess, and it finallyn is done. This the rate of datale waiting for a

rive controllers,ed for intra-chipA channels can than computersemory" copyingensive memorym the CPU to aI/O Acceleration

uence. Once the, it transfers allm buses back to

70

the CPU, but renders the CPU inactive for relatively long periods of time. Themode is also called"Block Transfer Mode" .

• Cycle stealing mode

The cycle stealing mode is used in systems in which the CPU should not bedisabled for the length of time needed for burst transfer modes. In the cyclestealing mode, the DMA controller obtains access to the system bus the same wayas in burst mode, usingBR (Bus Request)and BG (Bus Grant) signals, whichare the two signals controlling the interface between the CPU and the DMAcontroller.

However, in cycle stealing mode, after one byte of data transfer, the controlof the system bus is de-asserted to the CPU via BG. It is then continually requestedagain via BR, transferring one byte of data per request, until the entire block ofdata has been transferred. By continually obtaining and releasing the control of thesystem bus, the DMA controller essentially interleaves instruction and datatransfers.

The CPU processes an instruction, then the DMA controller transfers onedata value, and so on. On the one hand, the data block is not transferred as quicklyin cycle stealing mode as in burst mode, but on the other hand the CPU is not idledfor as long as in burst mode. Cycle stealing mode is useful for controllers thatmonitor data in real time.

• Transparent mode

The transparent mode takes the most time to transfer a block of data, yet it isalso the most efficient mode in terms of overall system performance. The DMAcontroller only transfers data when the CPU is performing operations that do notuse the system buses.

It is the primary advantage of the transparent mode that the CPU never stopsexecuting its programs and the DMA transfer is free in terms of time.

The disadvantage of the transparent mode is that the hardware needs todetermine when the CPU is not using the system buses, which can be complex.

71

36. DOMThe Domain Name

system for computers, servprivate network. It associateeach of the participating enwhich can be easily memorifor the purpose of computer

The Domain Name Symost Internet services becauDomain Name System distriand mapping those names servers for each domain.

Domain Name Syntax

The definitive descriptioRFC 1035, RFC 1123, and parts, technically called labe

71

MAIN NAME SYSTEM (DNS)e System (DNS) is a hierarchical distribrvices, or any resource connected to the

ates, various information with domain namentities. Most prominently, it translates dorized by humans, to the numerical IP adder services and devices worldwide.

System is an essential component of the fucause it is the Internet's primary directoryistributes the responsibility of assigning des to IP addresses by designating autho

ptions of the rules for forming domain namnd RFC 2181. A domain name consists of bels.

71

tributed naminghe Internet or aames assigned to domain names,ddresses needed

e functionality ofory service. Theg domain namesthoritative name

names appear in of one or more

72

Label

A label may contain zreserved for the root zone. Tcharacters in its textual repre

Host name

Although domain namable in an octet, host namcharacters allowed in their laof characters a through z, A known as the LDH rule (lette

Name servers

The Domain Name Sywhich uses the client–serveservers. Each domain has ainformation about that domait. The top of the hierarchy iwhen looking up (resolving)

72

in zero to 63 characters. The null label, of l. The full domain name may not exceed thepresentation.

ames may theoretically consist of any charaames use a preferred format and chara

r labels are a subset of the ASCII character A through Z, digits 0 through 9, and hypheetters, digits, hyphen).

System is maintained by a distributed datrver model. The nodes of this database s at least one authoritative DNS server tmain and the name servers of any domains y is served by the root name servers, the seg) a TLD.

72

of length zero, isthe length of 253

aracter representaracter set. Theer set, consistinghen. This rule is

database system,se are the namer that publishes

ns subordinate to servers to query

73

37.

A dongle is a small piprovide it with additional fusimilar devices meant to pdevices.

The CD-based parts requires a coded dongle be Some professional digital aurequired the presence of theorder to run.

Steinberg's Cubase ranfrequently send data to theelectronics inside the cartridg

To ensure compatibilioccupy the single cartridge accommodate them. Some exhost the different dongles unpirates were able to circumbinary to accept simulatedperformance.

Copy protection circumventi

Some unlicensed gamgames to pass along their auon the Nintendo Entertainme

73

37. DONGLE (ADAPTER)

l piece of hardware used to connect to ano functionality. The term "dongle" is also as provide additional forms of wireless co

ts catalog used by Volkswagen Group usebe plugged into a host computer's port in audio workstation packages on the Atari the supplied dongle in the computer's car

range and C-Lab's Creator and Notatothe dongle, which sends a response determridge.

ility with MIDI and other audio expansion ge port, some dongles had a pass-throughe expanders were also designed with backpl unique to a specific set of packages. Eventuumvent the dongle scheme by modifying ted dongle responses, at the expense of

vention

ame cartridges have a "daisy chain" that alr authorization, for instance to circumvent thment System.

73

nother device to associated with connectivity to

used since 1989 in order to run.ri TOS platformcartridge port in

tator packagestermined by the

on units that alsogh connector to

kplane sockets tontually, softwareg the program'sof stability and

t allows licensedt the 10NES chip

74

Small peripheral applications

A Chrome cast plugged into the HDMI port of a TV. The wire attached tothe other end is the USB power supply. Small devices that plug into otherequipment to add functionality are often referred to as dongles. for example theinfrared remote control adapters available for smart phones, or digital mediaplayers such as Chrome cast MHL.

A dongle enables adaptation to legacy standards such as HDMI viaconversion circuitry contained in the dongle itself. MHL dongles often allow USBconnections and/or device charging as well.

Dongle used in Different Fields

• Very short cables that connect relatively large jacks to smaller plugsallowing cables to be easily installed and removed from equipment withlimited space available for connectors.

• Smartphone (portable CD players before 2000)• PersCassette adapters enable cassette-radios to allow AUX in, like with

iPod/MP3 playeronal FM transmitters allow content from a portable mediaplayer, portable CD player, Smartphone, portable cassette player, or otherportable audio system to be heard on an FM radio.

• IDE/PATA connectivity can be re-channeled with some dongles:• Floppy disk drives have been emulated on solid-state "dongles" to ensure

legacy recognition, allowing SD cards to serve software to old Commodore64 and AppleII era computers.

• Allows SD cards to be recognized as "hard drives" on old DOS computers• Can be used in many video games.• USB host connectivity grants more flexibility to computer-based devices

• Older cars that "externalized" their CD players and changers from the headunit can now use "emulators" that allow USB and SD cards with MP3s andother audio files to be recognized as "tracks" to the CD control unit circuitry.

• The alternative term 'Pig-tail' is favored by some in the IT industry, due tothe appearance of a full-sized connection element, with a short, thin wireextending, somewhat reminiscent of the rear of porcine animals.

75

38. EMOTICON

By plenty of measures, 2015 has been a banner year for emojis or emoticons.A Welsh professor declared them the fastest growing language in the UK. TheNew York Times used one in a headline, and a grid of them graced the cover ofThe New Yorker. To cap it all, last month the Oxford Dictionaries declared thetears-of-joy emoji the “word” of the year.

It now feels hard to imagine online communication without emojis, even iftheir explosion in popularity among English speakers only dates to October 2011,when Apple’s iOS 5 update bestowed the little icons upon millions of iPhones.

(Gmail launched emoji support several years earlier, as did a number of third-partyemoji apps, but neither of these developments paved the way for their mainstreamadoption in the way that putting them on the iPhone’s virtual keyboard did.)

The very first emojis appeared on a handset sold by the company J-Phone(now Softbank) in 1997, but high prices kept it out of the hands of average citizens.The direct ancestors of the emoji we know and use today debuted in Japan in 1999.

“The emoji boom is over here in Japan,” says Shigetaka Kurita, the man

widely credited withcreating the adorable little runes. “They’re still around,

they’re still pervasive, but they aren’t a fad anymore,” he says in his Tokyo office.

He ventures that when Obama mentioned emojis on the White House lawn.

Understanding the rise and fall of emojis in their homeland requires a littlehistory. When Japanese telecom leader DoCoMo introduced proto-emojis in 1999,they were a core feature of the company’s i-mode service, the nation’s first to bring

the internet to mobile phones. In comparison to modern standards, the crude dot-matrix designs are something like digital versions of the primitive single-celledorganisms that once emerged from the primordial ooze.

Emojis help to add nuance to quick fire messaging Emojis were such aphenomenon, in fact, that they nearly sank the Japanese launch of the iPhone in2008. A collection of the new emoji, made by Emojipedia. By the time Google andApple began “localising” the emoji for use on Western computers and phones a

decade later, display technology had leapfrogged the old screens upon whichKurita’s first emojis dwelled.

76

The resulting demand Western designers to “fill in

the horror of Japanese emoji

Signs of the times: Emojis pa

The Oxford Dictionary

emoji, a decision that provoinclined. In fact, this additio“app” and “tweet” the year b

In 2008 the word was

are all words that once upon

without.So what’s next for

hashtags #stormtrooper, #Cemoticon automatically showcan now download the new “

and lots of very cold-looking

In 2016, Apple users bacon strips, champagne, a pand the introduction of Mrs Cl

76

nd for crisper graphics and more detailed iml in the blanks” with their interpretations, o

oji specialists.

jis past and present

nary word of the year for 2015 was the “

ovoked howls of derision from the non-teition was very telling: the word of the year before that.

was “bailout” – in reference to bailing out on a time we had no need for, but nowadays

for emojis? Fans of Star Wars can curre

#C3PO and #BB8 on Twitter and have ow up next to the word. Scandinavians andw “Nordic Emoji”, which includes long-haiing people.

ers can hope for 38 new emojis to play w a pregnant woman, a groom to go along wrs Claus.

76

d imagery forced, occasionally to

e “tears of joy”

-technologicallyear in 2010 was

ut a bank. Theseays we can’t live

urrently use the

ve a Star Warsnd scandi-lovershaired rock gods

with, including with the bride–

77

39. ENCAPSULATED POST SCRIPT (EPS)

Encapsulated PostScript (EPS) is a DSC-conforming PostScript documentwith additional restrictions which is intended to be usable as a graphics file format.In other words, EPS files are more-or-less self-contained, reasonably predictablePostScript documents that describe an image or drawing and can be placed withinanother PostScript document. Simply, an EPS file is a PostScript program, saved asa single file that includes a low-resolution preview "encapsulated" inside of it,allowing some programs to display a preview on the screen. At minimum, an EPSfile contains a Bounding Box DSC comment, describing the rectangle containingthe image described by the EPS file. Applications can use this information to layout the page, even if they are unable to directly render the PostScript inside.EPS,together with DSC's Open Structuring Conventions, form the basis of earlyversions of the Adobe Illustrator Artwork file format.

Identification

There are different ways in which EPS previews are handled, there is no oneway to identify an EPS file. A Windows-format EPS file containing a TIFF orWMF preview must start with the four bytes containing, in hexadecimal, C5 D0D3 C6. These bytes comprise the first four bytes of a 30-byte header, whoseremaining fields are six unsigned 32-bit integers and a 16-bit checksum. (Oftentwo zero bytes follow the header.) EPS files having "DOS" WMF or TIFFpreviews are widespread on all platforms. In all other cases an EPS file must startwith a line where a, b, c and d are all single digit numbers. A Mac-format EPS fileis accompanied by a resource fork. The preview is a PICT resource with ID 256.An EPS file on the Mac is expected to have a file type code of "EPSF", whether ornot it has a preview. An EPSI file will contain a line starting in the DSC prolog. Inmany cases they are not present at all.

Previews in Eps

EPS files also frequently include a preview picture of the content, for on-screen display. The idea is to allow a simple preview of the final output in anyapplication that can draw a bitmap.

78

Without this previewPostScript (PS) data inside machines until recently.

When EPS was firsPostScript were Apple MaciPostScript, which presentedimage while also including turned out to be easy to solvas forks) that are logically redata fork and a standard Mcould be moved about togetpreview often contains a bitmwhole image, providing very

Neither of these techsystem, however. When facbased versions of their proencoded into the header sectthey used the WMF (Windowprovide vector previews, simEPS files have a particular dpreview are all in the same not understand the format weformat known as an EPSI incallows for black-and-white Unfortunately, with several limited portability. An applicwill typically show an empcorrectly.

78

ew the applications would have to directde the EPS, which was beyond the capabi

first implemented, the only machines acintoshes. These machines could not direced Adobe with the problem of how to provg the actual PS version for the printer. On

solve, as the Mac file system includes two referred to as one file. By placing the Po Mac PICT resource in the resource fork,gether invisibly as if they were one file. Witmap it could also contain a vector represe

ery high quality previews.

echnologies is commonly used on any otfaced with the same problems on Microsoprograms, Adobe chose to instead includection of the PostScript. Sometimes, thoughdows Metafile) format instead. WMF has th similar to PICT on the Mac. Both of thear disadvantage: because the PostScript date file, they will cause printing errors if a

well enough to extract only the PostScript includes an ASCII-encoded preview bitmapte previews only. It is mainly used on U

ral different ways of representing the previplication which is unable to interpret a EPS

pty box on screen, but it will be able to

78

ectly render theabilities of most

s widely usingrectly render therovide a previewOn the Mac thiswo parts (knownPostScript in therk, both imagese. While a PICTresentation of the

other operatingosoft Windows-lude a TIFF fileugh more rarely,s the potential tothese PC formatdata, header and a program doespt data. A fourthap. This format

UNIX systems.view, they havePS file's preview to print the file

79

40. EXPAN

Expansion Card

Expansion card referreinterface adapter, or card, anslot on a desktop computcapabilities, such as graphiboards.

Types of Expansion Cards

Interface card (ASCSI, Serial, andModemMPEG DecoderNetwork cardSound cardVideo cardVideo capture ca

79

PANSION CARD FOR PRINTERS

rred to as an add-on card, expansion board,, an expansion card is a PCB that fits intoputer. An expansion card is used to ghics card. Expansion cards sometimes ca

ds

(ATA, Bluetooth, EIDE, Fire wire, IDE, Paand USB)

er

card

79

S

rd, internal card,to an expansion

give computer called daughter

, Parallel, RAID,

80

The purpose of add

motherboard is to add or Expansion cards are a way to

Expansion of Cards

An expansion cfunctionality to cMany differentsound cards, vide

Related Tags

Categories : Hardw

Synonyms : Printed

Etched

Computer Function And A

An expansion card is

capabilities. Expansion cards

Eg: Computer’s V

80

dding an expansion card or board to

r expand some sort of functionality to ty to upgrade a computer.

card is an electronic card board is usedto computers.

rent classes of expansion card are availabideo graphics card, network cards and so on

rdware Motherboards Electronics

ted Wiring Board (PWB),

ed Wiring Board (EWB)

nd Accesories

is a card which you can install to expand a

rds are inserted into expansion slots on the m

Video Card.

80

o a computer’s

o the computer.

sed to add extra

ilable, including on.

d a computer’s

he motherboard.

81

41. FILE A

A File Allocation Tmap of the basic units of login. When you write a new clusters that are not necessscattered over the disk.

When you read a ficlusters and places it as an this is a long Web page, it your hard disk.

DOS 5.0 and later versthe 16-bit FAT entry limit bWith 32-bit FAT entry (FAhard disk that can be supportlikely to take advantage of FA

Unused (0x0000)Cluster in use by a fileBad cluster (0xFFF7)Last cluster in a file (0

There is no organizatifirst available location on thethe first cluster used by the in the file, or an indication (links and end of file indicato

Example of File Allocation

A version of the file aand Windows 98. FAT32 incalso reduces the size of each(up to 2 terabytes) and better FAT32 and NTFS each use

81

E ALLOCATION TABLE (FAT)

n Table (FAT) is a table that maintains a logical storage on a hard disk that a file haw file to a hard disk, the file is stored inessarily next to each other; they may be

a file, the operating system reassembles an entire file where you want to read it. Foit may very well be stored on more than o

versions provide for support of hard disks uit by supporting separate FATs for up to fFAT32) support in Windows 95 OSR2, thorted is two. However, personal computer uf FAT32 with 5 or 10 gigabyte drives.

fileF7)

(0xFFF8-0xFFFF)

ation to the FAT folder structure, and files the volume. The starting cluster number is e file. Each cluster contains a pointer to thn (0xFFFF) that this cluster is the end of tators are shown below.

on Table

le allocation table (FAT) available in Windoincreases the number of bits used to addresach cluster. The result is that it can suppotter storage efficiency (less slack space). FAuse different cluster sizes depending on th

81

)

s and provides a has been stored in one or morebe rather widely

es the file from For example, ifn one cluster on

s up to two witho four partitions., the largest sizeer users are more

les are given ther is the address of

the next clusterf the file. These

ndows 95 OSR 2ress clusters andport larger disks FAT12. FAT16, the size of the

82

volume, and each file systemThe smaller the cluster size, unused space within a cluste

With the advent of Winclude the NTFS. NTFS is introduced with first versionof FAT’s deficiencies, it pro

file system is inherently mdamage in the event of a sysrecoverable via the chkdsk.e

Some FAT source code and

OS.ZIP - This is my

FAT32.HTML - This is an

FAT12.ASM - Example o

FAT16.ASM - Example o

FAT32.ASM - Example o

82

stem has a maximum number of clusters ize, the more efficiently a disk stores informster cannot be used by other files.

f Windows XP in October 2001, support waFS is a completely different file system from

ion of Windows NT in 1993. Designed to provides for greatly increased privacy and

more resilient than FAT, being less liksystem crash and it being more likely that ak.exe utility.

nd information:

my OS package! It contains three boot secto

an excerpt from the FAT32API.HLP file fro

le of a FAT12 boot sector.

le of a FAT16 boot sector.

le of a FAT32 boot sector.

82

s it can support.rmation because

was extended tom FAT that wasto address manynd security. The

likely to sufferat any damage is

ctor sources.

from Microsoft.

83

A flat file databasesystem as an ordinary "flat fiit, the file must be read completion of the database othe host's file system. In thisno structure for indexing anthe records. A flat file can be

Data transfer operations

Flat files are used notools in DB and CMS systtransfer tools to remote servbecome known as informatio

In recent years, this lawhich not only contain but transfer information are maiexpensive to modify. One crito perform mass data transfethat of flat files, which is gethis problem consists in XMLto flat files), which has nInterchange, which is often u

It is advisable that trabecause defining the comprethe file contents are readilycommunicating systems toproperties such as positioncircumstances where the shsystems becomes a problemIn order to successfullycommunication, format, valXML file data source), it is a

83

42. FLAT FILE

seis a database which is stored on its ht file". To access the structure of the data and in its entirety into the computer's me operations, the file is again written out inhis stored mode the database is "flat", whichand there are usually no structural relation be a plain text file or a binary file.

ns

not only as data storageystems, but also as dataervers (in which case theytion streams).

latter implementation has been replaced wiut also describe the data. Those still usinainframes employing specific procedures criticism often raised against the XML fosfer operations is that file size is significan generally reduced to the bare minimum. TML file compression (a solution that applie nowadays gained EXI standards (i.e., En used by mobile devices).

transfer data be performed via EXI rather pression method is not required, because libily available, and because there is no neeto preliminarily establish a protocol deion, alignment, type, and format. Howe sheer mass of data and/or the inadequaem, the only viable solution remains the uslly handle those problems connected

validation, control and much else (be it a is advisable to adopt a Data Quality Firewal

83

host computera and manipulatememory. Upon

in its entirety toich means it hasonships between

with XML files,sing flat files toes which are too format as a wayantly larger than. The solution tolies equally well Efficient XML

er than flat files libraries readingeed for the twodescribing data

wever, in thosequacy of legacy use of flat files.ted with data a flat file or anall.

84

Terminology

"Flat file database" may be defined very narrowly, or more broadly. Thenarrower interpretation is correct in database; the broader covers the term asgenerally used.

Strictly, a flat file database should consist of nothing but data and, if recordsvary in length, delimiters. More broadly, the term refers to any database whichexists in a single file in the form of rows and columns, with no relationships orlinks between records and fields except the table structure. Terms used to describedifferent aspects of a database and its tools differ from one implementation to thenext, but the concepts remain the same.

FileMaker uses the term "Find", while MySQL uses the term "Query"; butthe concept is the same. FileMaker "files", in version 7 and above, are equivalentto MySQL "databases", and so forth. To avoid confusing the reader, one consistentset of terms is used throughout this article.

However, the basic terms "record" and "field" are used in nearly every flatfile database implementation.

• Data types:Each column in a database table such as the one above is ordinarilyrestricted to a specific data type. Such restrictions are usually established byconvention, but not formally indicated unless the data is transferred toa relational database system.

• Separated columns:In the above example, individual columns are separatedusing whitespace characters. This is also called indentation or "fixed-width"data formatting. Another common convention is to separate columns using oneor more delimiter characters. More complex solutions are markup andprogramming languages.

• Relational algebra:Each row or record in the above table meets the standarddefinition of a tuple under relational (the above example depicts a series of 3-tuples). Additionally, the first row specifies the field names that are associatedwith the values of each row.

• Database management system:Since the formal operations possible with atext file are usually more limited than desired, the text in the above examplewould ordinarily represent an intermediary state of the data prior to beingtransferred into a database management system.

85

43. GEOGRAP

A Geographic InSystem (GIS) is a system deand present all types of spatiGIS Techniques and Techno

Modern GIS technodigitized data creation metcreation is digitization, wherdigital medium through thcapabilities. With the wide aavenue through which geogra

Relating Information from

GIS uses patio-tempoinformation. Just as a relatimany different tables using and/or extent in space-timincreasingly also temporallz representing, and respectiv

Data Capture

The current trend for (GIS) is that accurate mappiwhile in the field. Depictedused.

GIS Uncertainties

GIS accuracy dependsreferenced. Land surveyors accuracy utilizing the deriveimagery powerful computersand expectations of GIS to se

85

APHIC INFORMATION SYSTEM

Information System or Geographical designed to capture, store, manipulate, anaatial or geographical data.hnology

nologies use digital information, for wethods are used. The most common me

here a hard copy map or survey plan is tran the use of a CAD program, and gee availability of heads-up digitizing is becomgraphic data is extracted.

om Different Sources

poral allocation as the key index variablelational database containing text or numbng common key index variables, the key iime. Any variable that can be located rally, can be referenced using a GIS antively.

for geographical information systempping and data analysis are completedcted hardware technology) is mainly

nds upon source data, and how it is encodrs have been able to provide a high level

rived positions. High-resolution digital terraers and Web technology are changing the qo serve society on a grand scale.

85

MS (GIS)

l Informationnalyze, manage,

r which variousmethod of data

transferred into ageo-referencing

coming the main

ble for all othermbers can relatey is the locationd spatially, and

IS and x, y, and

coded to be datavel of positionalerrain and aeriale quality, utility,

86

Cartographic Modeling

The term "cartographicoined by in his PhD dissertawhich has the term in the titrefers to a process where sevsame area are produced, proc

Address Geocoding:

Geocoding is interpoladdresses or any other spatiaas a road centerline file withhistorically been interpolateroad segment. These are ususoftware will then place a dosegment of centerline. In thipositioned space as opposeincreasingly used to provide

Future of GIS

As discussed above, mactive GIS market has resulhardware and software comresult in a much wider apbusiness, and industry. It is will include the additional examine the variations in Eadvances in computer hardwto more and more GIS adopcoupled with the multimedpresentation of information aretention. The GIS of the futhe common man.

86

hic modeling" was probablyertation and later in his book title. Cartographic modelingseveral thematic layers of therocessed, and analyzed.

polating spatial locations (X,Y coordinateatially referenced data such as individual adith address ranges. The individual address lated, or estimated, by examining address rausually provided in the form of a table or dot approximately where that address belo

this case, the result of the geocoding will osed to an interpolated point. This approde more precise location information.

, many disciplines can benefit from GIS tesulted in lower costs and continual improvomponents of GIS. These developments application of the technology throughout is quite likely that the future GIS systemsal dimension of time, giving researchers n Earth processes over days, months anddware, software and remote sensing technoopting multimedia to represent data. Theseedia technologies will result in a powerfn and ideas to stimulate interest and enhanc future will also be more users friendly and

86

ates) from streetl addresses, suchss locations haves ranges along aor database. Theelongs along theill be an actuallyproach is being

IS techniques. Anrovements in thets will, in turn,out government,ms of the futurers the ability toand years. Thenology will leadese GIS systemserful and richerance informationand accessible to

87

44. GNUTELLA NETWORK

Its substantial user base and open architecture make it a good large-scale,if uncontrolled, test bed. We captured the network's topology, generated traffic,and dynamic behavior to determine its connectivity structure and how well (if atall) Gnutella's overlay network topology maps to the physical Internetinfrastructure. Our analysis of the network allowed us to evaluate costs andbenefits of the peer-to-peer (P2P) approach and to investigate possibleimprovements that would allow better scaling and increased reliability in Gnutellaand similar networks. A mismatch between Gnutella's overlay network topologyand the Internet infrastructure has critical performance implications

Developed in a 14 days “quick hack” by Nullsoft (winamp)

Originally intended for exchange of recipes

Evolution of Gnutella

Published under GNU General Public License on the Nullsoft web serverTaken off after a couple of hours by AOL (owner of Nullsoft)This was enough to “infect” the Internet

Gnutella protocol was reverse engineered from downloaded versions of theoriginal Gnutella softwareThird-party clients were published and Gnutella started to spread

BASED ON MESSAGE FLOODING

Typical values C=4, TTL=7One request leads to messagesHooking up to the Gnutella systems requires that a new peer knows at least oneGnutella host(gnutellahosts.com:6346; outside the Gnutella protocol specification)Neighbors are found using a basic discovery protocol (ping-pong messages)

88

Gnutella: Protocol Message Types

TYPE DESCRIPTIONCONTAINED

INFORMATION

Ping Announce Availability And ProbeFor Other Servents

None

Pong Response To A Ping

Ip Address And Port # OfResponding Servent;

Number And Total Kb OfFiles Shared

Query Search RequestMinimum Network

Bandwidth Of RespondingServents ;Search Criteria

Query HitReturned By Servents That Have

The Requested File

Ip Address. Port# AndNetwork Bandwidth OfResponding Servent ;

Number Of Result AndResult Set

PushFile Download Requests ForServents Behind A Firewall

Servents Identifier ;IndexOf Requested File ;Ip

Address And Port To SendFile .

CONNECTIVITY IN GNUTELLA

Follows a power-law distribution: P(k) ~ k-g

k number of links a node is connected to, g constant (e.g. g=2)distribution independent of number of nodes Npreferential attachmentlow connected nodes follow a constant distribution (?): more robust.

89

4

Google Drive is a synchronization service creallows users to store files files, and edit documents,presentations with collaboraencompasses Google, an officollaborative editing spreadsheets, presentations,launched on April 24, 2012 a2014.Client

For Google Drive toGoogle Drive storage, the Guser's computer. The client cone side to be propagated to Sundar Pichai of Google saibe tightly integrated with ChStorage

Google offers all usersstorage space that is shared services: Google Drive, GmPicasa Web Albums). Users account through a paid monadditional storage. Documenformats (including .gdoc, .count towards this quota. Inresolution less than 2048 x 2than 15 minutes also doquota. Uploaded files in MDocument formats (with posbe converted to Google's pcan be stored without countiAs of 13 March 2014, storag

89

45. GOOGLE DRIVE

a file storage andcreated by Google. Ites in the cloud, sharets, spreadsheets, andorators. Google Drive

office suite that permitsof documents,

ns, drawings, forms, and more. Googl2 and had 240 million monthly active users

to synchronize files between the user's ce Google Drive 'client' software must be runt communicates with Google Drive to cau to the other so they both normally contain tsaid that the Google Drive online storage Chrome OS version 20.

sers an initial 15 GB of onlinered across three of its most-used

mail, and Google+ Photos (akars can upgrade their free 15 GBonthly subscription plan to getents using Google Docs native

, .gslides, and .gsheet) do not. In Google+ Photos, photos ofx 2048 pixels and videos shorter

do not count towards this Microsoft Office and Openossible formatting changes) can

s proprietary formats, and thusnting against the storage quota.

rage plans offered by Google:

Storage

15 GB

100GB

1 TB

10 TB

20 TB

30 TB

89

gle Drive wasers as of October

r's computer ande running on thecause updates onn the same data.e service would

e Price

Free

$1.99 permonth

$9.99 permonth

$99.99 permonth

$199.99 permonth

$299.99 permonth

90

Ownership and LicensingGoogle has one unified set of terms of service and privacy policy for all its

products. According to CNET, unlike competing servicesDrop box and OneDrive, Google has broad rights to reproduce, use, and create derivative works fromcontent stored on the Google Drive, via a license from its users. This license isperpetual even after the user removes the material.Google Drive for Education

Google Drive for Education was announced on September 30, 2014. It wasmade available for free to all Google Apps for Education users. It includesunlimited storage and support for individual files up to 5TB in size.Popularity

On November 12, 2013, Google announced that Google Drive had 120million active users, a figure that the company was releasing for the first time. OnJune 25, 2014 at the Google I/O conference, Sundar Pichai announced that GoogleDrive now had 190 million monthly active users, and that it was being used by58% of the Fortune 500 companies as well as by 72 of the top universities.Data safety and privacy

Some of the issues that have to be considered to see if Google Drive is"enterprise-ready" include:

• Encryption of data in transit and storage• Service Level Agreements (regarding electronic discovery and incident

management)• Audit trails for users and administrators• Data segregation and data isolation

PresentationsPresentations created in Google Slides can be up to 100 MB – which is

about 400 slides. Uploaded presentation files that are converted into Google Slidesformat can be up to 50 MB.Spreadsheets

All the limits on spreadsheets have been removed in the newer version ofGoogle Sheets. In the older version, there could have been a maximum of 256columns per sheet and 200 sheets per workbook, with 400,000 cells in all.

Uploaded spreadsheet files that are converted to Google Sheets formatcannot be larger than 20 MB, and need to be under 400,000 cells and 256 columnsper sheet.

We express our sincere gratitude

for all those who have helped us, for

the successful launch of this book,

which is our new attempt .