2.2 Scotland Having enjoyed political independence until 1707, the survival of many of Scotland's institutions – notably its systems of law, religion and education – after Union with England contributed to the preservation of its singular identity. The different way in which Scotland began to be incorporated into the UK, through monarchical ascent (of James I of Scotland to the English throne) rather than by conquest (as was the case in Wales and Ireland), may account for the lesser impact the develo
2.1 England England played a dominant role in the medieval history of Britain, and the history of the UK is undoubtedly the history of the political and cultural power of England in comparison to Scotland, Wales and Ireland. In the making of the UK, each component nation played a different role: the English and Scottish kingdoms, the incorporation of Wales into the English Crown, and the subjugation of Ireland. The making of the UK was complex and fraught with violent confrontations, particularly virule
5.3.2 Productivity difference The preceding discussion has only considered what would happen if all women undertake less investment in human capital than men. If men and women invest to the same extent, human capital theory suggests that no wage differences would be observed. What happens, however, if there are differences in skill levels both between genders and within gender groups? To consider this we will also make the additional assumption that firms do not know when recruiting workers who are the most productive. Ho
4.3 Summary In this section we have tried to sketch some of the main lines of division in social constructions of social issues. The distinction between the natural and the social in constructing the causes that underlie social issues is a profound and recurrent one. A ‘social’ orientation involves the construction of social causes and conditions as the explanations for social issues. However, it is also important to bear in mind that such an orientation will itself be complicated by differences of p
3.6 Summary Three explanations of poverty developed by social scientists have been considered. The first sees poverty as natural or inevitable, the second focuses on the behaviour of poor people, while the third analyses poverty as the result of economic or political processes. Considering these explanations makes it possible to draw some conclusions about the social science approach to social problems: It relies on arguments making causal claims, rather than ass
4.2.2 ATM layer The primary functions of the ATM layer are associated with the routing and switching of ATM cells. Because ATM cells are packets, the switches are packet switches and the switching operation can be called forwarding, but by convention, because the ATM layer provides a connection-oriented service, the term ‘forwarding’ is generally not used. The path cells take and the resources allocated to them depend on their service category. This is determined when a virtual connection is
3.5 Internet protocol (IP) At the time of writing (2002), two versions of IP are available: versions 4 and 6. In this section I shall describe version 4, which is abbreviated to IPv4, as it is the more widely available version. Version 6 may eventually replace version 4 because it has some additional features that may prove essential for multiservice networks. IPv4 is the main TCP/IP protocol in the internetwork layer of the TCP/IP reference model. It supports a connectionless service between hosts in an interne
2.2 Vertical communication Figure 6 shows the OSI view of adjacent layers. The interface between two layers in the same system is called a service access point (SAP). One of the features of a service access point is that it has an identifier, or an address, which allows each communication between adjacent layers to be uniquely identified. The processes that communicate across the interface are called entities. These are typically software routines, but may also be hardware components. The notation in Figu
Acknowledgements The content acknowledged below is Proprietary (see terms and conditions). This content is made available under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 Licence Course image: S
6.7 Summary This section has looked at simulations, in which digital models of key aspects of the real world can be manipulated by programs. The examples included models of the world's climate, the early cosmos, stock markets, biological evolution and fantasy worlds and personalities. I've offered the view that simulation has far reaching implications for science, politics and society and will invite you to question that view in the final section.
5.5.5 Summary In this section I've briefly considered the very contentious question of what digital representations mean, but this debate must be left to another course. I have also described some of the devices that take digital information back into the analogue world of sight and sound, presenting it in a form that is meaningful to human eyes and ears.
5.5.4 Loudspeakers Speakers also produce an analogue output. The audio program inside the boundary converts the digital encoding of the sound to a series of electrical pulses that are sent to the speaker, where they cause a cone of stiffened paper (or some synthetic material) to vibrate in and out. This makes the air vibrate in the characteristic sound wave.
5.5.2 Printers Colour models were dealt with in Subsection 4.7. You probably also own a printer. Many computers now come with them as part of a package. There are two main types in use today: inkjets and lasers. InkJet printers work, as their name suggests, by firing tiny droplets of ink at the p
5.1 As to the meaning ... And this song is considered a perfect gem, And as to the meaning, it's what you please. This short section is devoted to rounding off the discussion so far. In Section 1 I remarked that a digital picture of some set of interesting features of the world is of no value unless we can examine it in some way – in other words, take it back acros
4.12 Sound and music Second only to vision, we rely on sound. Music delights us, noises warn us of impending danger, and communication through speech is at the centre of our human lives. We have countless reasons for wanting computers to reach out and take sounds across the boundary. Sound is another analogue feature of the world. If you cry out, hit a piano key or drop a plate, then you set particles of air shaking – and any ears in the vicinity will interpret this tremor as sound. At first glance, the p
4.2.4 Keyboards Every computer comes with a keyboard. They are still the main way of taking text across the boundary into the computer. The one I'm using to type this course has 109 keys. Under each key is a pressure sensor that detects when the key has been pressed and sends an electronic signal into the computer. There, a small program called the BIOS (Basic Input/Output System) translates the signal into the appropriate numeric code. Other software stores that code in a suitable place in the memory.
3.10 A final word – analogue and digital worlds So there we have it. On the one hand is our world, an analogue world – a world of light and sound, of taste and touch. On the other side of the boundary is the computer's digital world – a bleak world of binary numbers. Before I leave the topic, though, I should point out that some of the points I've made may be controversial. For a start, it's not entirely clear whether the world we inhabit is fundamentally analogue. Quantum theory tells us, for instance, that quantiti
3.6 A world of numbers Although we may not all enjoy it, using numbers to count and do arithmetic seems to be a natural human activity. For computers, however, there is nothing but numbers. They were designed from the first to handle numbers and that is still all they do. The cleverness of modern software may make it appear that they do much more, but this is an illusion. The interior world of the computer, the territory inside the boundary, is a world of numbers and nothing else. Some of you may have
3.4 Discrete things In contrast to analogue quantities, which change continuously, discrete quantities change in a series of clear steps. Again, an example should make this clear. In Subsection 3.2, I considered the case of an analogue volume control. A discrete volume control is shown in Author(s):
2.7 Manipulation As I suggested above, we can change a digital version of some aspect of reality in any way we want. I've used the simple example of tinkering with a digital photograph, but the possibilities for transformation go far beyond this. We can set up elaborate replicas of real-world systems and inspect them in detail. We can establish digital models and run them forward in time to see what might happen in the future. We can even create completely imaginary digital worlds and then explore them as if
