.


:




:

































 

 

 

 


High-Definition Television




High-definition television (HDTV) is a television system that has more lines per picture than present systems, and thus produces much sharper images. At present American TV has 525 lines per image and European TV 625, while high definition systems may have more than 1000. Many observers feel that the battle for high definition TV markets will be the next great world economic battle.

Digital HDTV can provide sharper, clearer pictures and sound with very little interference or other imperfections. Of perhaps greatest importance, digital television sets will potentially be able to send, store and manipulate images as well as receive them, thereby merging the functions of the television set and the computer.

HDTV potentially offers a much better picture quality than standard television. HDs greater clarity means the picture on the screen can be less blurred or fuzzy. It also brings such benefits as smoother motion, richer and more natural colours, and the ability to allow a variety of input devices to work together. With HDTV the lack of imperfections in the television screen often seen on traditional television is another reason why many prefer high definition to analog. Problems such as snow caused from a weak signal, double images from ghosting or multi-path and picture sparkles from electromagnetic interference do not occur with HDTV broadcasts. The colours will generally look more realistic, due to greater bandwidth. The visual information is about 2-5 times more detailed overall. The gaps between scanning lines are smaller or invisible.

However there are some reasons why the best HD quality is not usually achieved. The main problem is a lack of HD input. Many cable and satellite channels and even some high definition channels are not broadcast in true HD. Also image quality may be lost if the television is not properly connected to the input device or not properly configured for the inputs optimal performance. Moreover viewers will have to upgrade their TVs in order to see HDTV broadcasts, incurring household expense in the process. Adding a new aspect ratio makes for computer confusion if their display is capable of one or more ratios but must be switched to the correct one by the user. All these moments have led to slower undertake of the technology as many people wait to see what becomes the ultimate de-facto standard.

 

16. Make questions to the text.

 

17. Find the sentences containing:

a) the main idea of the text;

b) specifying information (technical characteristics of HDTV, potential of HDTV, picture quality, why people prefer high definition to analog, problems facing HDTV operators, reasons for slower undertake of this technology).

 

18. Sum up the text using the key words, word combinations and the topical sentences.

 

19. Express your attitude to the facts given in the text. You may use the following phrases:

 

1. It is full of interesting information .

2. I find the text rather / very cognitive .

3. Ive learnt a lot .

4. I dont agree with it .

 

 

Part C

 

20. Look through the following text, define the information presented in it and entitle the text.

 

Text C

 

Audio broadcasting, in which an analog audio signal is converted into a digital signal before being transmitted, is also known as digital audio broadcasting (DAB) and high-definition radio. Digital radio reception is virtually free of static and fading, pops, and hisses; overall, adjacent stations do not interfere within one another, audio clarity and volume are improved, and weather, noise, and other interference cease to be a factor. Digital radio can be land based (or terrestrial) or transmitted via satellite. In either case, a special receiver is required to decode the multiplexed signal; the receiver may contain a small display that provides information about the audio content (such as the name of the artist or title of the music).

The land-based technology was first deployed in Great Britain in 1995, and has since become established throughout Europe. The first satellite-based digital radio system was World Space, which orbited the first of its three geostationary earth orbit (GEO) satellites in 1998. Each satellite transmits three overlapping signal beams carrying more than 40 channels of programming; most of world (except mainly North America and Australia) is covered. In metropolitan areas where tall buildings, overpasses, and other obstacles can interfere with the signals when, for example, the receiver is in a moving vehicle, a network of ground-based repeaters retransmit the signals. The receiver also buffers the signal briefly so that if it loses the satellite signal it can use one from a repeater to maintain a continuous broadcast.

 

21. Look through the text and say how digital radio works.

22. Say where the presented information can be used.

 

 

UNIT IV

COMPUTER SECURITY

 

Part A

Word List

abuse /q'bju:s/
account /q'kaunt/ - , ;
authorize /'O:TqraIz/ ,
back up  
client /'klaIqnt/ , () -
confidential /"kPnfI'denSql/ ,
confirm /kqn'fq:m/
consent /kqn'sent/ , ,
damage /'dxmIdZ/ , , ,
entice /In'taIs/ ; ,
firewall /'faIqwO:l/ (), , ( ), ( )
harm /hQ:m/ , , , (in; to); ,
host /hqust/
identify /aI'dentIfaI/ , ;
malicious /mq'lISqs/ ,
monitor /'mPnItq/ ,
penetrate /'penItreIt/ ,
pertinent /'pq:tInqnt/
pop-up   -, ( -), ,
secure /sI'kjuq/ ,
share /Seq/
sophisticated /sq'fIstIkeItId/ ( , , . .)
spyware /'spaIweq/ ( )
surreptitious /"sArqp'tISqs/ ,
threat /Tret/ ,
vulnerable /'vAlnqrqbl/ ;
worm /wq:m/ (, )

1. Translate the following words which may have some similarity with the words in Russian but often differ in meaning.

Regular, share, provider, online banking, identity, data, security, pretend, transfer, release, prevent, safe, spam, prevent, software, cracker, virus, directory, infect, surf, confidential.

 

2. Read the following words in each line and define their part of speech. Translate the words into Russian.

 

1) administer, administrator, administration, administrative;

2) prevent, preventive, prevention;

3) define, definition, definite, indefinite;

4) protect, protection, protective, protector;

5) provide, provision, provider;

6) serve, server, service;

7) detect, detection, detector, detected, detectable;

8) spy, spyware, anti-spyware, espionage;

9) safe, safety, safely;

10) suspect, suspicion, suspected;

11) secure, security, insecure, secured.

3. Match the following terms with their definitions.

1) spyware a) freeware of deliberately poor quality with some, but generally not all, of the features of a software application, intended to entice those who download the freeware to buy the complete application;  
2) nagware b) copyrighted software given away for free by the author. The author retains the copyright, which means that you cannot do anything with it that is not expressly allowed by the author. Usually, the author allows people to use the software, but not sell it;  
3) adware c) malicious software that has been designed (programmed) specifically to damage or disrupt a computer system. The most common forms of malware are computer viruses, worms, and Trojan horses;  
4) malware d) software characterized by frequent updates, fixes, and patches;
5) software e) any software that covertly gathers user information through the user's Internet connection without his or her knowledge, usually for advertising purposes;
6) freeware f) the term given to software that routinely issues a pop-up window or other form of visual interface asking the user to register a product, purchase an application or take another form of action;  
7) baitware g) a general term used to describe a collection of computer programs, procedures and documentation that perform some tasks on an operating system;  
8) dribbleware   h) any software package which automatically plays, displays, or downloads advertisements to a computer after the software is installed on it or while the application is being used. Some types of it are also spyware and can be classified as privacy-invasive software.  

 

4. Translate the following sentences paying attention to the words in bold type.

1. Unfortunately when something is shared, it is open to abuse.

2. Your goal is to prevent others from accessing your data remotely.

3. You can also set the firewall to ask for your confirmation before granting access to an unknown program.

4. The leading threats to the security of your computer come from four types of malicious software.

5. Spyware tracks your online activity.

6. A good antivirus program will continually monitor all of your file transfers.

7. Password will prevent unauthorized parties from opening your desk or laptop and looking through your files.

8. It is a software program that is designed to search through your hard drive, CDs and floppy disks for any known or potential viruses.

9. One of the biggest mistakes that many PC users make is that they fail to back up pertinent information.

5. Complete the following sentences filling in one of the words given below:

worm, by default, antivirus software, phished, hacker, password, virus, updated, attacked

 

1. Unless your computer is used exclusively on a mountain top in Outer Mongolia and never exchanges information of any sort with any other computer, anywhere, it is likely to be by a virus program soon.

2. With very few exceptions, a computer without is just like a car without brakes - it simply isnt safe.

3. Even if you arent running a web server ‑ be sure to keep your system with the latest patches ‑ the security of your system depends on it!

4. is a program or piece of code that is loaded onto your computer without your knowledge and runs against your wishes. Viruses can also replicate themselves.

5. Windows XP doesnt ask for any login information or make you authenticate yourself in any way in order to access the system.

6. Whatever you do, NEVER make your from a word that appears in a dictionary.

7. The term refers to individuals who gain unauthorized access to computer systems for the purpose of stealing and corrupting data.

8. A is a special type of virus that can replicate itself and use memory, but cannot attach itself to other programs.

9. The golden rule to avoid being is to never click the links within the text of the e-mail. Always delete the e-mail immediately.

6. Read the text and arrange the following items of the outline in accordance with the text.

1. Computers have become widely used because of significant changes in computer technologies.

2. You must protect your PC.

3. Threats you face working in the internet.

4. Firewalls as one of the first means of protecting your PC.

5. Back up your stuff to be on the safe side.

6. Types of malicious software.

7. Antivirus software and its function.

8. Good passwords can make your PC more secure.

Computer Security

Computer technology has changed a lot over the past 20 years. People who would normally never touch a computer now utilize such a device almost every day to get their work done. They use e-mail and surf the web regularly.

When you are connected to the Internet you are sharing a vast network with hundreds of millions of other users. This shared network provides resources that
15 years ago were never thought possible. Unfortunately when something is shared, it is open to abuse. On the Internet this abuse comes from hackers and virus creators. Their sole intent is to cause chaos and/or harm to your computer system and millions of other computer systems all over the world. 20 years ago this may not have been as much of a problem, but in todays world of online banking and identity theft, this can be a huge problem.

It is in fact a horrifying moment when a computer user realizes that a virus has managed to penetrate his or her CPU system and destroyed years of data and hard work. In an effort to minimize the probability of having to experience such a stressful moment you must take care of your PC and protect it.

Start with the software changes. Your goal is to prevent others from accessing your data remotely. A combination of computer firewalls and antivirus PC security software can take your sensitive information from unprotected to secure with very little effort. A firewall can be considered your first line of defense when connected to the internet. In order for information that is behind a firewall to be sent or received from your computer, permission must be granted by the firewall. You can set up your firewall to always grant access to programs you trust and always block access to programs you do not trust. You can also set the firewall to ask for your confirmation before granting access to an unknown program.

It is important to be aware of the different types of viruses that exist and also to know how they work in order to be able to protect your PC.

The leading threats to the security of your computer come from four types of malicious software: viruses software designed to invade computers and to copy, damage or delete data; worms sophisticated viruses that can reproduce themselves and spread to other computers without your interaction; Trojans, named for the Trojan horse, viruses that pretend to be helpful programs while destroying your data, damaging your computer and stealing personal information; spyware software that tracks your online activity. Activity Spyware may bombard you with pop-up advertising, collect your personal information, or change the settings on your computer without your knowledge or consent.

Most computer users have now installed in their computers memory certain antivirus software protecting their computer from viruses that are transmitted over the internet and through file exchanges. A good antivirus program will continually monitor all of your file transfers.

Anti-virus is a vaccine. Its purpose is to protect your computer from unwanted harmful software implanted on your computer unknowingly. It is a software program that is designed to search through your hard drive, CDs and floppy disks for any known or potential viruses.

However, it is still advisable to fully scan your entire system for viruses once a week. You can schedule this scan to run automatically while you are asleep or away from home. You will also need to sign up for automatic updates to the antivirus program, as new viruses are released daily.

Another useful step is to use strong passwords. Set an administrative password even if you are the only user of your computer. This will prevent unauthorized parties from opening your desk or laptop and looking through your files. Passwords should be easy to remember but difficult to guess. Change them regularly, and use passwords that contain numbers and characters rather than easy to guess names and words. Whatever you do, NEVER make your password from a word that appears in a dictionary. Password cracking tools are everywhere, and if your password can be found in a dictionary or is a very common word, a password cracker can easily find it and use it against you. Use readily available utilities, like cracker, that will identify all insecure passwords quickly and easily. If you want to allow house guests or friends to use your computer, create a separate guest account that does not have administrator access. Check online at Microsoft.com for instructions on setting up accounts or ask a computer-savvy friend for help.

One of the biggest mistakes that many PC users make is that they fail to back up pertinent information. Make a hardcopy of this information and keep it in a secure location. To be on the safe side, make a rule for yourself to back up your stuff.

 

7. Match the letter of the correct answer to the following questions.

1. Why has internet become so widely used by people all over the world?

a) because those who would never touch a computer now utilize their computer for surfing in the Internet;

b) because it is possible to share a network with hundreds of millions of other users;

c) because Internet provides services and access to unlimited resources of the WWW.

2. What are the threats of work at the Internet connected with?

a) Internet is full of chaos;

b) You will have to change your PC software;

c) It is open to abuse of different kinds.

3. What are hackers and crackers aims?

a) to make Internet more effective;

b) to minimize the possibility of stressful moments connected with the consequences of their PC infection;

c) to harm your computer or get profit using the information stored at your computer.

4. What is the primary purpose of installing firewalls at your PC?

a) to give access to all programs trying to reach your CPU system;

b) to control the information sent from your computer;

c) to get maximum control of the information sent and received from your computer denying access to ambiguous programs.

5. What are the viruses spread for?

a) for their reproduction and improving the performance of users computers;

b) for getting access to other users computers in order to damage, destroy or steal personal information;

c) only for playing jokes.

6. Why is antivirus software often called a vaccine for your computer

a) because it helps you to update your computer;

b) it makes your computer friendly to viruses;

c) it serves for protecting your computer from any known harmful programs that can creep in without your knowledge.

7. What kind of passwords are better?

a) names and dates of birth as they are easy to remember;

b) short number codes;

c) a combination of numbers, characters and symbols as they are more difficult to devise.

 

8. Read the following sentences and say which of them are true or false.

1. People use Internet only for gaming.

2. There is nothing to care about getting connected to the Internet.

3. Some 20 years the problem of Internet security was not as much of a problem.

4. It is a great fun to find the results of your hard work destroyed or corrupted.

5. Installing firewalls, antivirus software and using good passwords are minimum things one should take care of to protect his PC.

6. Malicious software makes the operation of your PC more effective.

7. Spyware implanted at your computer lets you keep track of other users online activities.

8. Worms are viruses that remain resident in one computer.

9. To provide greater safety passwords should be as simple as possible.

10. There is always sense to make hardcopy of your most important information.

9. Think of the tips you would give to a beginner on the ways to secure his PC while working at the Internet.

 

Part B

 

10. Read the title of the following text. Make your predictions about the contents of the text.

 

What is Spyware?

 

In simplest terms, spyware is a type of malware that watches what users do with their computer and sends this information to the creator (or occaisionally a hacker) over the internet. Generally, different types of spyware collect different information about a user. Less harmful programs attempt to track what websites a user visits, sending this information to an advertisement agency. More malicious programs may try recording what a user types to intercept passwords or credit card numbers, sometimes referred to as keyloggers. Other spyware programs simply launch pop-ups with advertisements. This type of malware may also be referred to as adware.

Originally, spyware just referred to malicious software that spied on (or monitored) the user, sending information back to its creator. More recently users have come to use the term spyware regarding any software that does any sort of spying to benefit a third party. This includes adware and keyloggers, amongst other types of malware that monitors the user or allows full or partial control of a computer systems operation to a remote user without the consent of the machine user (such as Trojan horses).

Unlike viruses and worms, spyware does not usually self-replicate. Spyware may exploit known weaknesses in computer security or be installed by free software (freeware), infecting computers for commercial gain. Spyware typically does this by displaying unsolicited pop-up advertisements (sometimes to coercing the user into buying an anti-spyware product created by the same person(s) that made the spyware), theft of personal details (such as stealing usernames, passwords, and credit card numbers), monitoring of Web-browsing activity (for marketing purposes), or simply routing HTTP requests to advertising sites.

Spyware is currently one of the major security threats to computers running Microsoft Windows OSs. As Microsofts internet browser, Internet Explorer, is closely tied in with the OS, when a security vulnerability is exploited through Internet Explorer, the operating system itself may be exploited. Due to the fact that Microsoft Windows series of OSs are widely used, the vulnerabilities found in windows systems are often exploited as there is usually more chance of finding an unpatched system running Windows at random than finding, for example, an unpatched OS/2 system. To prevent this, use an alternative browser like Firefox or any other one.

Notes:

1OS Operating System .

2HTTP - HyperText Transfer Protocol .

 

11.Read the text and find out the topical sentences of the paragraphs.

12.Write out key words and phrases revealing the contents of the text.

13.Divide the text into logical parts. Entitle each part.

14.Find 1 or 2 sentences which can be omitted as inessential in each logical part.

15.Find the paragraph in the text which describes the ways of coercing into consenting installation of a program.

16.Sum up the text using the key words and word combinations and the topical sentences.

17. Say which facts presented in the text youve already been familiar with. Do you consider the information presented in the text useful?

18. Using internet, find some information on anti-spyware programs and present it in class.

Part C

19. Look through the following text and title it.

Text C

 

What else is left now that you have a virus scanner and an application to help keep track of the spyware that can affect your machine? A firewall of course! A firewall is a device or a program that helps stop other users from getting into your computer. Every user should know at least something about firewalls, as they can be the extra layer of security that protects you while youre online. If you were infected with a trojan horse program, there is a chance that it can let someone take complete control of your PC as though they were sitting at their keyboard! These programs work by opening up a port on your computer and then allowing anyone with the client to connect to it and gain control of your computer.

Imagine you were doing some home banking over the internet and someone was watching the whole time. To make matters worse, some of these applications have a mechanism thats built into them that lets the thief delete the server portion of the trojan, which means that you would never even know that it was there.

One way to help stop this from occurring is by using the anti-virus software that can find and delete trojan programs for you. When you use firewall software, it asks you if you want to allow a program to access the internet in the first place. This will stop such trojan programs from talking to whomever controlled them. Another thing these firewalls can do is prevent inbound traffic to your machine. The trojan programs have both inbound and outbound traffic to and from your PC as commands are sent to your PC. Worms that spread over the internet use outbound traffic to scan and send themselves out to other hosts. This is only one of the many features a firewall provides to you, and I highly recommend using one.

If you have Windows XP, you should have installed Service Pack 2, which fixed a number of security flaws, but also put something called the security center on your machine. This helpful new application checks to see what it can do to protect you, and the new XP firewall that comes bundled is turned on by default!

 

20. Find the following information in the text:

what is meant by firewall;

examples of grave consequences caused by malicious software;

ways of combating virus programs.

 

21. Think of the tips you would give your friend to make his computer secure.

22. Devise your ABC rules for unsophisticated PC users. Include tips that refer not only to software but hardware security as well.

 

UNIT V





:


: 2016-10-06; !; : 406 |


:

:

, , .
==> ...

1833 - | 1485 -


© 2015-2024 lektsii.org - -

: 1.651 .