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4.1 Introduction

I'll now look at what these components do in the communication system, using the mobile phone system as an example.


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3.2 Looking into the 'means of conveying a message'

The diagram in Figure 6 shows that, for communication to take place, there needs to be some means of conveying the message between the sender and the recipient. I am now going to look at the essential components of 'means of conveying a message'. In other words, I shall treat 'means of conveying a message' as a system and look at
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1.6.2 Different types of sound

Sounds come in four categories.

  • Sound effects. Many UIs contain a range of warning beeps and reassuring sounds confirming that operations have been completed. These can include naturalistic sounds, such as the sound of a piece of screwed-up paper dropping into a waste paper basket.

  • Music. Many composers use computer systems to compose music, and programs such as games make extensive use of music. Short sequences of musical
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1.6.1 The role of sound

The use of sound is becoming increasingly common, particularly for the following types of application.

  • Applications where the eyes and attention are required away from the screen. Relevant examples include flight decks, medical applications, industrial machinery and transport. If you are a runner, you may have a heart rate monitor that allows you to monitor how fast your heart is beating. This is often indicated by an auditory beep, which speeds
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Acknowledgements

Except for third party materials and otherwise stated (see terms and conditions), this content is made available under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 Licence

Figure 1 ENIAC Computer. Photo © Science Photo Library

Rozin, D. ‘Wooden Mirror’,
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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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6 A look to the future

So what will computers do for you next? Perhaps they will be the key to solving transport problems. Driverless cars, controlled by computers, are under development. If these ever come to fruition perhaps they could help to reduce the number of road traffic accidents by automatically reducing their speed when they come too close to another car. Or perhaps journeys could be made faster and less frustrating because cars will use communicating computers to analyse traffic density and move along t
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3.2 What does a processor look like?

So what do these devices that are manufactured in such vast quantities look like? Processors are manufactured as integrated circuits. Essentially they are circuits, around the size of a fingernail, which contain many millions of electronic components manufactured as one very complex circuit. Figure 4(a) shows how a processor manufactured as an integrated circuit is packaged so it can be used as a component in an electronic circuit. The pins of the package are connected to the integrated circu
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Further reading

There is not a lot published on distributed development paradigms. The book by Coulouris et al. [2] indirectly introduces some of the paradigms introduced in this course. Lynch's book [3] on distributed algorithms is full of algorithms which are message passing based. The book by Patzer and 14 others [4] is a good practical introduction to many of the technologies detailed in this course. One of the few current books on JavaSpaces has been writt
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Keep on learning

Study another free course

There are more than 800 courses on OpenLearn for you to
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Conclusion

This free course provided an introduction to studying Computing and ICT. It took you through a series of exercises designed to develop your approach to study and learning at a distance and helped to improve your confidence as an independent learner. 


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5.1 Introduction

The final approach to developing distributed systems is based on a radical view of such systems. The approach is based on work carried out by two American academics, Nicolas Carriero and David Gelerntner. These two academics developed a language known as Linda in the 1980s. The language, and its associated technology, has always been thought of highly by other academics within the distributed systems area, but has never taken off in terms of commercial use. However, in the late 1990s Sun deve
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Acknowledgements

The following material is Proprietary (not subject to Creative Commons) and used under licence (see terms and conditions).

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

Course image: Seika in Flickr made available under Creative Comm
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References

Brown, M. and J. Honeycutt (1998) Using HTML 4. Indianapolis, IN: QUE.
Choi, S., D.O. Stahl and A.B. Whinstone (1997) The Economics of Electronic Commerce. Indianapolis, IN: Macmillan.
Coulouris, G., J. Dollimore and T. Kindberg (2001) Distributed Systems Concepts and Design. Harlow: Addison-Wesley.
Gamma, E., R. H
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2.5.5 Email providers

These are sites which provide free email facilities; often they provide other facilities such as sending anonymous mail and constructing mailing lists. Such sites are valuable to users who are too impecunious to be able to afford conventional mailing software and to frequent travellers who can access such sites anywhere in the world. Their main disadvantage is that they tend to be slow compared with conventional mailing utilities such as Microsoft Outlook and Eudora.


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2.5.1 Anonymous remailers

An anonymous remailer is a website which enables you to send an email anonymously to some recipient. The main reason for this is to do with something known as spam. This term describes unsolicited email which tries to sell the recipient something.

Spam

Throughout the
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2.4 Auction sites

These are sites on the web which run conventional auctions. There are two types of auction: those that are carried out in real time, where participants log in to an auction site using a browser at a specified time and bid for an article until the highest price is reached and no other bids are forthcoming. The other type of site – and the most common – is where an item is offered for sale and a date advertised after which no more bids are accepted. Such sites make a profit from two sources
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2.1 An example – supply chain management

Before looking at the wide variety of e-commerce application areas that have flourished over the last decade in more detail, it is worth looking at one which may not be familiar to a reader, but which saves companies huge amounts of resources. The application involves a supply chain. A supply chain is a set of relationships between a number of companies who have a symbiotic relationship with each other in that one company supplies commodities or services to other companies which, in tu
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Exploring children's difficulties with language and literacy
What happens if children aren’t making progress with language and literacy, and what sort of learning impairments might be the cause? How can the study of children’s thinking help us to understand these learning difficulties? This album offers insights into some of the problems faced by children with the developmental disorders dyslexia, poor comprehension and specific language impairment. In the main audio tracks, educators, therapists and researchers explore why children might have languag
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Learning to change
This free course, Learning to change, is for people who are thinking about making changes in their lives, such as returning to study or taking a different direction at work. It will help you build on what you already know; consider the choices open to you; use your skills and qualities to achieve change; and make plans for the future. First published on Mon, 08 Apr 2013 as Author(s): Creator not set

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