4.2 Representing text

Study note: You will need to refer to the Reference Manual while you are working through this section.

Please click on the 'View document' link below to read the Reference Manual.

3.4 Input and output considerations

CCDs are not inherently able to detect colour, only brightness. So it is necessary to rely on the fact that any colour of light can be made up from the three primary colours of light: red, blue and green. (Note that the three primary colours of light are different from the three primary colours of pigments.) Each CCD in the array is therefore overlaid with a red, blue or green filter and so detects the brightness of, respectively, the red light, the blue light or the green light falling on it
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6.1 Networks

Next I'll be looking more closely at the ‘network’ block in Figure 8, and in particular at the links that must be present before communication can take place. I'll introduce you to just a few of the forms that these links can take; links may be physical ones, such as cables, or they
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3.1 Introduction

Generally, when we talk about communication between humans, we mean one person conveying information to another person. Figure 6 shows a basic model, or representation, of a communication system for getting a message from the sender to the recipient. The diagram shows the sender (User
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4.9 Ethical, social and political aspects

The introduction of identity cards has proved controversial in several countries, for example France (where identity papers have long been a requirement) and Australia. Generally the issues have related to the questions like: ‘What are these cards actually for?’, ‘Whose interests do they serve?’ and ‘What use will be made of the underlying database of identity data?’ Opponents of identity schemes have pointed out that totalitarian regimes have always found identity systems very us
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6.1 Introduction

Section 5 discussed the ISMS planning and documentation process in general and also went into the details of Stages 1, 2 and 8 of the ISMS documentation task. In this section, we shall discuss Stage 3 of the ISMS documentation task and see how to define a systematic approach to risk assessment. We shall also look at the asset identification task. The remaining two tasks, risk assessment and risk treatment, are outside the scope of this unit.


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5.2 The Standard's approach to planning an ISMS

The Standard describes the planning of an ISMS, which it refers to as the ‘Plan activity’, as follows.

The Plan activity … is designed to ensure that the context and scope for the ISMS have been correctly established, that all information security risks are identified and assessed, and that a plan for the appropriate treatment of these risks is developed. It is important that all stages of the Plan activity a
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1 Why is information security important?

This unit introduces you to information security and its management.

A succinct definition of information security might run as follows:

Information security is the collection of technologies, standards, policies and management practices that are applied to information to keep it secure.

But why is it important to secure information? And how should its security be managed? To s
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11.3 Controlling cookies in Internet Explorer

It's important to remember that you have the ability to control cookies.

This exercise will take you through setting a level of security on cookies using Microsoft Internet Explorer version 6, while the next page deals with Mozilla Firefox version 1 (you do not have to be online to do this exercise).

Using Internet Explorer

  • Open your browser.

  • On the top menu bar of the browser choose Tools > Internet Options.

  • <
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4.1 What is a search engine?

Search sites are powered by a search engine: a program that can search for web pages that match your query, and then return a list of hits. The list of hits arrives at your browser as a web page, complete with links to the pages the search engine has found. A website such as the Open University may provide its own search engine which searches only its own web pages, but the big search sites claim to search the entire Web. This is a stunning claim: Google claims to search over four billion web
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3.6 Tracing your family tree

In order to show some of the possibilities provided by the Internet, we have gone straight to searching for material online. A careful family historian would take a more measured approach, starting with the evidence to hand within their own family, and researching offline materials as well. Tracing your family tree involves repeating these steps:

  • start with what you know

  • record it

  • decide what to pursue next

  • <
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2.6 Finding images on the Web

As with websites, one of the easiest ways of searching for images is to use a search engine such as Google. You will see that above the Google search box are some words that allow you to select what you are searching for: web, images, groups, news, and more.

2.3 Searching for information on the Web

What do you do if you don't know the URL of the website you are looking for, or haven't been able to browse to it? The Web is not like a library – it isn't carefully organised and catalogued, and it is growing all the time. Luckily, there are search sites that can help you find what you want.

2.3.1 Portals

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2.2 Browsing for information on the Web

One way to find what you are looking for on the Web is to start from sites that you know are likely to have useful ‘links’ on them, like the main Open University pages or the Open University Library pages. These opening pages are known as home pages and are a bit like the contents page of a book. The home page usually gives you some information about the content of the website, often with links to other pages of information held on that site and on sites elsewhere. By clicking on a link
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Learning outcomes

By the end of this unit you should be able to:

  • use search engines confidently to locate information and images on the Web;

  • critically address resources that you locate on the Web;

  • describe some of the processes underlying search engines.


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7.2 An overview of RFID

The technology behind RFID is relatively straightforward and has been in use in some form for many years. You may have even used it yourself or seen it in use – for example in a ‘proximity card’ entry system in buildings, and in pet identification where a microchip is inserted just below an animal's skin. But you are likely to hear a lot more about it in the future and increasingly to see it deployed. This is because, at the time of writing (early 2005), the technology is receiving a st
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7.3 Using flowcharts to describe a task

Application programs are designed to perform specific tasks. These tasks range from the relatively simple to the extremely complex. In this section you will look at what is involved in planning a program to perform some simple tasks.

In order to write a program, the task the program will perform has to be first written as a list of actions. The actions have to be given in an order that will ensure the task is carried out successfully.

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2.7 Digitisation of the news

Into the digital era

Remember that this paper was written in 1995, at which time digital techniques were just beginning to take over in electronic newsgathering. Taylor therefore concludes his paper with comments on the nature and impact of changing to digital techniques.


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Acknowledgements

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Grateful acknowledgement is made to the following for permission to reproduce material:

Ince, D. Developing Internet Applica
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6.3 Summary

This section examined how computers can be used to control machines. It used the household washing machine as a case study and explored how the microcomputer contained in such a machine is programmed to:

  • provide an interface for the user to operate the machine;

  • control the way the machine carries out the operations chosen by the user.

The washing machine case study also illustrated the necessity of building safety fea
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