2.4 Pulse spreading and bandwidth

Activity 3

Calculate the maximum signalling rate given by the Nyquist rate for the 1550 nm window, assuming that it runs from 1450 nm to 1610 nm.

Answer

Using the
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Activity answers

Study Note: As outlined in the text I have not provided answers to all Activities. This is for two reasons:

  1. For some activities only you can devise the answer and any I gave would be distracting or unhelpful.

  2. For others in-text answers are given.


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4.5 Torture

The question of torture is also raised in the play. Herrenvolk claims that he does not do the torture; it is some Uzbekistan outfit that does it. He actually gives them a justification by saying, in a rather glib way, that it is a lot easier to open a human being than an encrypted laptop. Of course, the question is, is it ever ‘right’ to exploit this as a means of finding things out? I suspect most of us would say ‘no’.


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3.3 Magnetic tape recorders

Experiments showed that the use of paper tape coated with iron oxide particles significantly improved the signal-to-noise ratio and enabled a lower tape speed to be used. A plastic-based version of this magnetic tape, developed by the German company BASF, led to the development of a commercial tape recorder with audio characteristics that could nearly match those of the gramophone record, but not at an economical price. Secret work on tape recorders was undertaken by the Germans throug
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1 Capturing sound

Have you ever listened carefully to a recording of your own voice?

In this first activity, I want you to make a short recording of your voice.

Activity 1 (Optional)

Note: This optional activity requires the use of a
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7.2.4 Trap 4: words and wordiness

I have seen some effective rich pictures with lots of words in them but they are quite rare in my experience. More often, lots of words make the rich picture less rich. Part of the later use of a rich picture might include looking for patterns. Words inhibit your ability to spot patterns.

If you do use speech bubbles, use what people say, not your interpretation, unless the bubble is about some general attitude. Examples might be ‘Aaagh!’, ‘Help!’, ‘Oops!’ – the sort of th
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3.2 Learning by experience

It's a familiar idea but it implies two activities: learning and experiencing. Both activities need to happen if I am to say that learning from experience has happened. Experiencing seems to have two components. The first is the quality of attention that allows me to notice the experience and its components. The second is memory. Calling experience to mind allows me to examine the experience and to think about it in ways that were not possible at the time. Learning is what I take away from th
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3.1 What are you hoping to learn?

Anticipations and preconceptions are an important determinant of how people learn, so before you read on, I would like to you to record some of what you are experiencing now as you begin the course.

It's important to get these impressions noted down now, because new ideas and new impressions will quickly overlay the experience. What you are experiencing now will be re-interpreted as new understandings emerge. You are also likely to form some judgements about your expectations. So before
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2 Part 1 Starting the unit

Welcome to T306_2 Managing complexity: a systems approach – introduction. As I write, I experience a sense of excitement. For me, as for you, this is the beginning of the unit. These are the first few sentences I'm writing and so, although I have a good idea of how the unit is going to turn out, the details are by no means clear. Nevertheless, the excitement and anticipation I, and maybe you, are experiencing now is an important ingredient in what will become our experiences of the u
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1.2.7 Key points

Diagrams can be helpful in clarifying your thinking because:

  • they can summarise complex situations, allowing you to appreciate the complexity while seeing the individual components and the connections between the components;

  • they can give you new insights into a situation by making you think carefully about the components and connections and by helping you to learn more effectively.


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Learning outcomes

After reading this unit you should be able to:

  • appreciate diagrams as a powerful aid to thinking and acting;

  • distinguish between systems diagrams and diagrams helpful in systems work;

  • demonstrate sufficient skills to ‘read’ and ‘draw’ a wide range of diagrams, following given conventions, that help improve your understanding of a situation;

  • select diagrams suited to the needs of the situation you are investigating and the purp
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13 Products for markets

Japanese car companies came to dominate in many countries in the 1980s, and this was in part attributable to their marketing research and emphasis on designing products for particular market segments. An example is the car firm Nissan, which researches national preferences for various car attributes in different countries. For instance, it is reputed to have provided its cars with softer suspensions in Germany, firmer steering in the UK, and noisier exhausts in Italy. There are other reasons
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12.1 Gathering data

In this section I will review some of the approaches and methods used by companies for identifying and exploiting marketing opportunities.

All over the world, producer companies have increasingly learned to keep a careful watch on emerging consumer requirements and changing user needs and wishes. They have not only learned to listen to what consumers say, but to watch what they do. Techniques used in market research to gather consumers’ views on products include both quantitative meth
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9.1.5 Immersion

Click on the 'View document' link below to read Jordan on 'Immersion'.

View document16.1KB PDF document<
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9.1.2 Limits

Second, decide the limits and the variations to the user trip or trips that you are going to take. It is usually a good idea to extend the trip into activities that both precede and succeed the immediate use of the product you are investigating since this may lead you into devising an improved, more integrated overall solution. Similarly, variations on a basic trip – different times of day, different weather conditions, different requirements – will probably bring to light a wider range o
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8.1.2 Feedback

A second important principle is providing feedback to the user – for example, when you press a button it moves and clicks, or you hear some other sound or you see a light to indicate the action has been registered by the machine.

Here's another short video clip from Phillip Joe at IDEO, this time on feedback.

8.1.1 Visibility

Recall that a key usability design feature identified by Donald Norman – from his analysis of using everyday objects such as doors – was visibility. An everyday object such as a door, or a control such as a button on a product should appear to be obvious about how it is used, and indeed it should perform that obvious function. For example, is it obvious how you insert a disc into a player? Is it obvious how you switch the machine on, adjust volume, and so on?


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6 Inclusive design

This section reveals the importance of designing things to suit all potential users.

Inclusive design (or universal design) means designing products so that they can be used easily by as many people as wish to do so. This may sound an obvious goal, but the fact is that many people – some estimates suggest as many as one-fifth of all adults – have difficulty carrying out ordinary tasks with everyday products.

Many elderly and disabled people cannot carry out – certainly with
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