4.2.3 Lens system

The function of the lens system is to project an image onto the CCD light sensor. A well-designed system ensures that the image is sharp – in focus – and bright. To achieve this, what is needed is a good-quality glass lens (or rather a series of lenses) and accurate focusing. The brightness of the image depends upon the size of the lens. The bigger the lens, the brighter the image, but bigger lenses are more difficult to make and therefore more expensive. Also, of course, bigger lenses me
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Acknowledgements

Acknowledgements

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Grateful acknowledgement is made to the following sources for permis
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8 CASE tools

Computer Assisted Software Engineering (CASE) tools were developed to support the professional system developer and improve their productivity in the complex task of developing large information systems.

The benefits that may accrue from the use of such tools are many. From a developer’s viewpoint, they provide support for modelling aspects of the system using a variety of notations and techniques: from diagrams to mathematics and text, producing prototype code, and even verif
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8.2 Example of a university registration data model

Here is a statement of the data requirements for a product to support the registration of and provide help to students of a fictitious e-learning university.

A UK-based e-learning university needs to keep details of its students and staff, the courses that it offers and the performance of the students who study its courses. The university is administered in four geographical regions (England, Scotland, Wales and Northern Ireland).

Information about each student should be initially
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8.1 Introduction

One type of data model is an entity–relationship data model.

Experience has shown that data can be best described by relationships between entities. An entity is anything of interest about which data is recorded, such as roads, weather stations, trucks and weather station readings in the IceBreaker project in the book MRP. In general, there will be many relationships (or associations) linking the entities. A trivial example is the fact that a given weather reading
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7.2 Exercises

Exercise 5

Draw an activity diagram for the main success scenario for the check out guest use case.

Answer

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6.12 Self-assessment questions

SAQ 1 Actors

  • (a) Explain why the actors in a use case diagram do not represent actual individuals.

  • (b) Suggest a guideline that will help you decide whether or not to include
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5.1 More information about modelling techniques

The four remaining diagramming techniques are described in separate sections below, which you should now study:

Diagramming Technique Section
Use case modelling Use Cases and Activity Diagrams
Activity diagrams Use Cases and Activity Diagrams
Entity–
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Learning outcomes

This is what you should have achieved when you have completed your study of this unit:

  • Understand the concept of e-government, and the associated benefits and drawbacks.

  • Understand how a relational database differs from a flat database, including the function and construction of a joining table.

  • Understand some of the basic principles of XML.

  • Understand the basic principles of biometric identification and verification systems


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4.1.2 The network

The network is a communication channel in that it conveys data from the transmitter to the receiver. The network may also manipulate data in some way, and it may also store or retrieve data.

In a mobile phone system, the network conveys the message from User l's handset to User 2's. It will also store the identity of User 1 and the duration of the call. This data is used to work out the amount to charge User 1, which is a form of manipulation of data. A network can be very comple
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1.6 Implementation

Implementation involves the construction of a database according to the specification of a logical schema. This will include the specification of an appropriate storage schema, security enforcement, external schema, and so on. Implementation is heavily influenced by the choice of available DBMS, database tools and operating environment. There are additional tasks beyond simply creating a database schema and implementing the constraints – data must be entered into the tables, issues relating
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4 Supply and demand: Kiran's story

The first six months have just flown by. I've really enjoyed working with the two or three schools that I chose following my conversation with my friend who is a student. I feel that I have established a good reputation for reliability as well as keeping the classes moving forward in their work. My family
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6 Communicating and OpenLearn

A variety of software tools are available to help you communicate with others to rework content and to enable your learners to work with each other. As well as Compendium, the mind mapping tool described in Activity 3, FlashMeeting enables video-conferencing through a web browser, and the Comments allow asynchronous discussion
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1.1 Teaching languages: language awareness

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5.2 Before the visit

In preparation for the visit the tutor will need to:

  • Telephone the school to agree a date and time with the mentor and school co-ordinator for the visit.

  • Write to the school confirming the visit. This letter should:

     

    1. set out the tasks and activities the mentor will need to do;

    2. request that a focus for the observation is agreed with the student teacher and mentor;


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4.12 The implications of gender differences in communication

Activity 20

0 hours 20 minutes

If it were true that men and women tend to communicate in very different ways, what might be the implications for health and social care in terms of:<
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2.8 ‘Difference’, power and discrimination

These first few sections have emphasised the point that differences are always produced in a social context, and that a key part of that context is power relationships. As pointed out earlier, a key element of Foucault’s social constructionist approach is that the way in which people are categorised in society (for example, by gender, ethnicity or age) involves an exercise of power that reflects the ideas and interests of dominant groups. One of the key arguments against essentialist views
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Learning outcomes

After studying this Unit you should be able to:

  • demonstrate your understanding of how social welfare policy started to evolve at a national level after World War II;

  • locate information relevant to social welfare through reference to a range of sources;

  • evaluate the reliability of information from different sources.


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Introduction

In this unit we explore questions of access to community services. To make what might be quite a dry task more challenging we use a fictionalised case study of two people for whom access to community services is particularly problematic. Jim and Marianne are both long-term heroin addicts. Additional problems associated with their addiction are homelessness and physical illness. Their situation raises both practical questions, about how services can be accessed, and moral questions, about enti
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1 Is grief a medical problem?

Grief is a fertile area for debate and controversy within health care professions, and its significance as something in need of medical attention has been debated by both health analysts and social commentators alike. Is it a ‘natural’ phenomenon that should be respected and acknowledged, but one that requires that the bereaved individual is left alone to experience it in their own way? Or should the bereaved person be assisted with intervention which relies on the presumption that grief
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