DTU 

Semester 1 

8860063407 

Shruti_0802@yahoo.co.in 

Unit 1 FIT 

FIT _Unit 1 FIT Unit 1 

FIT _Unit 1 Unit 

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 Prepared By Shruti Khatri 

Hello All 

Just felt like sharing my own experiences as an engineering student. I don’t know how many of you were or are introverts even today, but honestly, I had been an extreme introvert before my college years who only knew what books are but nothing actually about the outer world. My graduation brought enormous amount of changes individually. Its only few fortunate students who get to hold the most prestigious positions for their campus as an organization. Probably, I was equally opportunate to be considered in that list where, I was the placement cell member, the lead technical fest organizer, lead cultural fest organizer, Class representative, Stream representative (for all engineering years of Information technology branch),college anchor for all 4 years, an emotional counselor for my friends, lead reception committee organizer, an all time debate/extempore, jam session winner and yes, among the first 5 class toppers academically. 

I never say that I was always fearless for the stage. No ...infact I had been very very reserved as a child who hesitated to open even to her parents, who never shared a word with others, who never thought that she can ever do anything for herself, who thought dreaming and fulfilling those dreams is an impossible act only seen in the television world but not in reality, who found herself ugly to stand in the crowd and yet smile, who even got suicidal feelings inside and who always thought God is un­fare, unkind and biased. 

But, yes, things changed for the better, and here I am... 

Yes, I do face failures, I do have goof ups. But I know now.....This is not the end ..but a beginning to correct my failures,,,, to be brave, ,,,to understand life and love it even with all my failures and rise to achieve my ambitions, my family ,my friends and yes, “myself”. Bring God to your life and you least have to worry about where your life is moving. He loves you more than you love yourself. 

Have a happy Reading!!..:­) 

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Data 

Definition: 

(1) In computing, data is information that has been translated into a form that is more convenient                                 to move or process. Relative to today's computers and transmission media, data is information                           converted into binary digital form. 

2) In computer component interconnection and network communication, data is often                     distinguished from "control information," "control bits," and similar terms to identify the main                         content of a transmission unit. 

3) In telecommunications, data sometimes means digital­encoded information to distinguish it                     from analog­encoded information such as conventional telephone voice calls. In general,                     "analog" or voice transmission requires a dedicated continual connection for the duration of a                           related series of transmissions. Data transmission can often be sent with intermittent connections                         in packets that arrive in piecemeal fashion. 

4) Generally and in science, data is a gathered body of facts. 

Topic 1: Information 

Definition: 

It is Data that (1) has been verified to be accurate and timely, (2) is specific and organized for a                                       purpose, (3) is presented within a context that gives it meaning and relevance, and (4) that can                                 lead to an increase in understanding and decrease in uncertainty. 

The value of information lies solely in its ability to affect a behavior, decision, or outcome. A piece of information is considered valueless if, after receiving it, things remain unchanged. 

Topic 2: Difference Between Data And Information 

Data Information Raw facts & figures Processed data Meaningless Data with meaning No Context Data with context No value added to data Value added through­ 

Summarization Analysis Organization Is un­certain Decreases un­certainty and brings 

understanding 

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Topic 3: Introduction to information representation in digital media, text, images, graphics, animation, audio, video etc. 

Multimedia 

Definition: 

Multimedia means that computer information can be represented through audio, video, and                       animation in addition to traditional media (i.e., text, graphics/drawings, images). Multimedia is                       the field concerned with the computer controlled integration of text, graphics, drawings, still and                           moving images (Video), animation, audio, and any other media where every type of information                           can be represented, stored, transmitted and processed digitally. 

A Multimedia Application is an application which uses a collection of multiple media sources e.g. text, graphics, images, sound/audio, animation and/or video. 

What is HyperText and HyperMedia? 

Hypertext is a text which contains links to other texts. The term was invented by Ted Nelson around 1965. 

Hypermedia 

HyperMedia is not constrained to be text­based. It can include other media, e.g., graphics, images, and especially the continuous media – sound and video. 

Examples Hypermedia Applications 

1) The World Wide Web (WWW) is the best example of a hypermedia application. 2) Powerpoint 3) Adobe Acrobat 

Key Issues for Multimedia Systems 

The key issues multimedia systems need to deal with 

are: 

1) How to represent and store temporal information. 2) How to strictly maintain the temporal relationships on playback/retrieval. 3) What process are involved in the above. 4) Data has to be represented digitally. So, require Analog–Digital Conversion, Sampling 

etc. 5) Large Data Requirements — bandwidth, storage. 

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A Brief Look at Multimedia Data: 

Input Format 

Text and Static Data 

1) Source: keyboard, speech input, optical character recognition,data stored on disk. 2) Stored and input character by character: 

– Storage of text is 1 byte per character (text or format character). – For other forms of data (e.g. Spreadsheet files). May store format as text (with 

formatting) others may use binary encoding. 3) Format: Raw text or formatted text e.g HTML, Rich Text Format(RTF), Word or a 

program language source (C, Pascal, etc..) 4) Not temporal — BUT may have natural implied sequence e.g.HTML format sequence, 

Sequence of C program statements. 5) Size: Not significant w.r.t. other Multimedia data. 

Graphics 

1) Format: constructed by the composition of primitive objects such as lines, polygons, 

circles, curves and arcs. 2) Input: Graphics are usually generated by a graphics editor program (e.g. Illustrator) or 

automatically by a program (e.g.Postscript). 3) Graphics are usually editable or revisable (unlike Images). 4) Graphics input devices: keyboard (for text and cursor control),mouse, trackball or 

graphics tablet. 5) Graphics standards : OpenGL, PHIGS, GKS 6) Graphics files usually store the primitive assembly 7) Do not take up a very high storage overhead. 

Images 

1) Still pictures which (uncompressed) are represented as a bitmap (a grid of pixels). 2) Input: digitally scanned photographs/pictures or direct from a digital camera. 3) Input: May also be generated by programs “similar” to graphics or animation programs. 4) Stored at 1 bit per pixel (Black and White), 8 Bits per pixel (Grey Scale, Colour Map) or 

24 Bits per pixel (True Colour) 5) Size: a 512x512 Grey scale image takes up 1/4 Mb, a 512x512 24 bit image takes 3/4 Mb 

with no compression. 6) This overhead soon increases with image size . 7) Compression is commonly applied. 

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Audio 

1) Audio signals are continuous analog signals. 2) Input: microphones and then digitised and stored 3) CD Quality: Audio requires 16­bit sampling at 44.1 KHz 

Even higher audiophile rates (e.g. 24­bit, 96 KHz) 4) 1 Minute of Mono CD quality (uncompressed) audio requires 5 Mb. 5) 1 Minute of Stereo CD quality (uncompressed) audio requires 10 Mb. 6) Usually compressed (E.g. MP3, AAC, Flac, Ogg Vorbis). 

Video 

1) Input: Analog Video is usually captured by a video camera and then digitised. 2) There are a variety of video (analog and digital) formats 3) Raw video can be regarded as being a series of single images. There are typically 25, 

30 or 50 frames per second. 4) Typical PAL digital video takes 720 *576 pixels per colour frame. 5) Digital video clearly needs to be compressed for most times. 

Topic4, 5: Need & Value of Information: Why Data & Information Are Valuable! 

Information is the lifeblood of any organization. Damaged or lost data can cause disruptions in                             normal business activities leading to financial losses, law suits, etc. Information systems, which                         comprise hardware, software, data, applications, communication and people, help an                   organization to better manage and secure its critical corporate, customer and employee data.                         Information systems also improve integration and work processes...the benefits go on and on. 

Factors affecting the value of information in organizations 

Completeness 

If information is not complete, bad decisions would be made. For example, if you were choosing                               a car, and had no information about safety on any of the models you were contemplating, you                                 could make a really skull­crushing decision. 

Accuracy 

It makes sense that accurate information is the best kind of information. Beware when you are                               searching for information... especially on the Internet. Any old idiot (like me) can say anything                             he or she likes. You must judge each piece of information based on 

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i) What you already know (but sometimes what you know might be wrong!) ii) The reputation of                                 the information source (have they usually been accurate in the past?) iii) Has the information                             been checked by others? (books are carefully edited by experts, webpages might not be) iv) Is                               the author biased? (Do they work for the company who makes the product they are praising? Are                                 they prejudiced?) v) Is the information up­to­date (timely)? Are you buying a computer with a                             1998 magazine ad? 

Timeliness 

Information can be valuable one day, and useless the next. A newspaper article examining the                             chances of candidates in a Federal Election might be spot­on the day before the vote, and                               ridiculous the day after. All information has a "use by" date. Be very wary of consuming                               information that is out of date! 

With books, check the date of publication. Some topics rarely change with time (e.g. the themes in Shakespeare). Others change by the minute (e.g. what stock is good value). 

With webpages, check the "Last Updated" date, if there is one (be cautious if there isn't one and the issue is changing constantly.) Old webpages are sometimes only good for historical research. 

Consistency 

Beware if your source of information changes its mind at various places, or contradicts itself. It                               is the sign that it is untrustworthy. If a newspaper review of a film glows about it, then later pans                                       it, you can be sure the author is either confused or stupid. In either case, treat all the information                                     with the caution it deserves. 

Validity 

To be valuable, information should be unbiased, representative and verifiable. 

Bias can be conscious (e.g. advertisements) or unconscious (through prejudice or ignorance). 

If information neglects key topics or issues, it might not represent the full knowledge­base you                             need to know. If, for example, you visit an American website discussing world history, don't be                               surprised if it seems that America won both World Wars single­handedly ­ even though they                             started late in each of them. 

If information cannot be independently verified, it should be treated with utmost caution. In                           court, "hearsay" evidence is treated with near­contempt. Just because someone says something                       happened does not mean it really happened. There needs to be a way to investigate claims                               beyond what a single person (or organization) says. If you believed everything you were told                             without checking out the facts, you'd be a fool. 

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Appropriateness 

Information can be presented in different ways. Some ways may be meaningful and relevant, and formatted to suit the user’s needs , others may not. 

If you are searching for basic information on networks and you find a site that discusses intricate                                 technical specification of file servers that you simply don't understand ­ the information is                           worthless to you. It might be a pot of gold to someone else, but it has no value to you. 

Similarly, if you were researching the causes of the common cold and you found a book that                                 said, "Colds are caused by bugs, so be careful if your playmates sneeze near you", the                               information might be valid, but in an inappropriate form. 

Information might be presented in a fashion that is inappropriate to your needs. For example, if                               you were a security operative in a large retail chain, and you suspected an employee was stealing                                 money, you'd want detailed transaction records, and not a summary graph showing the store's                           sales over a month. 

On the other hand, if you were the CEO of the company and you wanted an indication of the                                     company's progress, a thousand cash register receipts would be useless. You'd need the                         information summarized or aggregated to be of any use to you. 

Uniqueness 

Sometimes, information is valuable if you are the only one who has it. A business that owns                                 unique intellectual property will guard it with all its might because it is valuable while they alone                                 possess it. Patents, marketing ideas, ad campaigns, new products etc all fall into this category.                             Once their secrets are known, they are worthless. That explains why organizations tend to be                             quiet about initiatives and new products until they are publicly released. 

Relevance 

If information is not relevant to the recipient, it is worthless. If you are not a gambler and you                                     hear a tip that a horse is a "dead certainty" at Randwick tomorrow, it is useless information. For a                                     puntser, however, the information might be pure gold. Information is not universally valuable: it                           is valuable only to a person who needs it and can use it. 

Topic 6: Quality Of Information: Information Quality Characteristics 

Since there is so much information out there, professionals have defined characteristics that are critical. Here are the key criteria used to determine the value of information: 

▪ ACCURATE ­ The information must be true, verifiable, and not deceptive. Accurate                         information is based on empirical data and can be validated by comparing sources or checking                             for internal consistency. 

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▪ CURRENT ­ The information must be applicable to the present time. Keeping information current requires a process of eliminating the old and adding the new. 

▪ RELEVANT ­ Relevant information applies to the interests of the individuals who use it for the                                 decisions they are facing. It should reduce a person's uncertainties about work and education                           while facilitating choice and planning. 

▪ SPECIFIC ­ For information to be specific, it must contain concrete facts. General observations                             are often interesting and can provide a background for further analysis, but specific facts are                             essential to realistic planning and decision making. 

▪ UNDERSTANDABLE ­ People using information must be able to comprehend it before they                           can use it. Data must be analyzed and converted into words. The content of the message should                                 avoid ambiguities and be informative to the intended audiences. 

▪ COMPREHENSIVE ­ The information should include all the important categories within its scope of coverage. 

▪ UNBIASED ­ This characteristic is about the motivation or purpose for which the information                             is being produced and delivered. It is unbiased when the individual or organization delivering the                             information has no vested interest in the decisions or plans of the people who are receiving the                                 information. 

▪ COMPARABLE ­ The information presented should be of uniform collection, analysis, content, and format so that you can compare and contrast the various components.. 

These are some of the most important qualities that quality resources strive to achieve in making information useful for planning and decision­making. 

Topic 7: Compression 

Definition: 

Compression is the reduction in size of data in order to save space or transmission time. For data                                   transmission, compression can be performed on just the data content or on the entire                           transmission unit (including header data) depending on a number of factors. 

Explanation: 

Data compression squeezes data so it requires less disk space for storage and less bandwidth on a                                 data transmission channel. Communications equipment like modems, bridges, and routers use                     compression schemes to improve throughput over standard phone lines or leased lines.                       Compression is also used to compress voice telephone calls transmitted over leased lines so that                             more calls can be placed on those lines. In addition, compression is essential for                           videoconferencing applications that run over data networks. 

Most compression schemes take advantage of the fact that data contains a lot of repetition. For                               example, alphanumeric characters are normally represented by a 7­bit ASCII code, but a                         

compression scheme can use a 3­bit code to represent the eight most common letters. 

In addition, long stretches of "nothing" can be replaced by a value that indicates how much "nothing" there is. For example, silence in a compressed audio recording can be replaced by a 

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value that indicates how long that silence is. White space in a compressed graphic image can be replaced by a value that indicates the amount of white space. 

Compression has become critical in the move to combine voice and data networks. Compression                           techniques have been developed that reduce the data requirements for a voice channel down to 8                               Kbits/sec. This is a significant improvement over noncompressed voice (64 Kbits/sec) and older                         compression techniques yielding 32 Kbits/sec. 

Two important compression concepts are lossy and lossless compression: 

• Lossy compression: With lossy compression, it is assumed that some loss of information is                             acceptable. The best example is a videoconference where there is an acceptable amount of frame                             loss in order to deliver the image in real time. People may appear jerky in their movements, but                                   you still have a grasp for what is happening on the other end of the conference. In the case of                                       graphics files, some resolution may be lost in order to create a smaller file. The loss may be in                                     the form of color depth or graphic detail. For example, high­resolution details can be lost if a                                 picture is going to be displayed on a low­resolution device. Loss is also acceptable in voice and                                 audio compression, depending on the desired quality. 

• Lossless compression: With lossless compression, data is compressed without any loss of data.                           It assumes you want to get everything back that you put in. Critical financial data files are                                 examples where lossless compression is required. 

The removal of information in the lossy technique is acceptable for images, because the loss of                               information is usually imperceptible to the human eye. While this trick works on humans, you                             may not be able to use lossy images in some situations, such as when scanners are used to locate                                     details in images. 

Lossy compression can provide compression ratios of 100:1 to 200:1, depending on the type of                             information being compressed. Lossless compression ratios usually only achieve a 2:1                     compression ratio. Lossy compression techniques are often "tunable" in that you can turn the                           compression up to improve throughput, but at a loss in quality. Compression can also be turned                               downed to the point at which there is little loss of image, but throughput will be affected. 

When you send or receive information on the Internet as larger text files, either singly or with                                 others as part of an archive file, that may be transmitted in a zip, gzip, or other compressed                                   format. 

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