Performance Analysis and Optimization of Asynchronous Circuits

Analytical techniques are developed to determine the performance of asynchronous digital circuits. These techniques can be used to guide the designer during the synthesis of such a circuit, leading to a high-performance, efficient implementation. Optimization techniques are also developed that further improve this implementation by determining the optimal sizes of the low-level devices (CMOS transistors) that compose the circuit

Agrippa's trilemma: scepticism and contemporary epistemology

Take any belief of yours – even one about which you feel supremely confident. The Sceptic will ask: why do you think it is true? You might take yourself to have a very good reason to believe what you do. But the sceptic will also want to know why you think that this second thing is true as well. You might offer yet a third reason for believing that, but the sceptic won't stop. He will want, again, to know why you believe that third thing. How will you choose to answer the sceptic's constant questioning? You might just keep going on, offering yet more and more reasons every time the sceptic questions you. Or you might argue in a circle, so that you defend your original belief by an argument which eventually appeals again to that very belief. Or you might argue that your original belief can eventually be defended by appeal to a set of assumptions for which you do not have any further reasons. But are any of those options really acceptable, or should you give up your original belief? If the latter, then since the sceptic could question any of your beliefs in this way, does that mean that you should give up all of your beliefs? Are you open to blame and criticism just for believing anything at all? The Pyrrhonian sceptic tries to convince us that the answers to these questions are “yes”. In this work, I explicate the sceptical strategy in detail and consider philosophical attempts to evade its dire conclusion. My development of Scepticism draws on the ideas of Sextus and three of his scholars, Barnes, Bailey and Machuca, as well as BonJour and Oakley. A number of philosophers have criticized Scepticism on the grounds that it presupposes a nonordinary definition of “knowledge”. The sceptic tries to show that our common-sense belief that we know all sorts of things about the world is really a giant error, but the only way he manages to do it, according to these philosophers, is by starting with a definition of “knowledge” vastly removed from our usual one. This strategy is the dominant way of criticizing Scepticism in contemporary epistemology. It is deployed by John Greco, Alvin Goldman, Mark Kaplan and many others. Against these philosophers, I urge that the sceptic's using the word “know” in a non-ordinary way does not harm the substance of his arguments at all. A number of philosophers have argued that the sceptic's standards for right or justified belief should be rejected. I argue that the standard which the Pyrrhonian lays down is not at all ridiculous. All he asks of us is that we have some reason, no matter how weak, for believing that P rather than -P – a reason which might convince someone who did not already believe that P. And so the sceptic lays down a standard which it may be very difficult to give up. What's more, I argue, by discussing the views of Michael Williams and Michael Huemer, that it is far from clear that there is anything in the neighbourhood that is particularly plausible as an ethics of belief. These two broad anti-sceptical gambits are the currently dominant ones. In showing them to be unsatisfactory, I show that the sceptic still has us firmly in his net

Getting It: On Jokes and Art

“What is appreciation?” is a basic question in the philosophy of art, and the analogy between appreciating a work of art and getting a joke can help us answer it. We first propose a subjective account of aesthetic appreciation (I). Then we consider jokes (II). The difference between getting a joke and not, or what it is to get it right, can often be objectively articulated. Such explanations cannot substitute for the joke itself, and indeed may undermine the very power of the joke to evoke an appropriate response. Sometimes the discourse of art critics can have a similar effect. We therefore explore the analogy between getting jokes and appreciating works of art (III), and find it unexpectedly strong. Finally (IV), we consider Wittgensteinian grounds for thinking as we do, considering the language game of joke-telling, the relevance of seeing aspects, and giving reasons

Out-of-home food outlets and area deprivation: case study in Glasgow, UK

BACKGROUND: There is a popular belief that out-of-home eating outlets, which typically serve energy dense food, may be more commonly found in more deprived areas and that this may contribute to higher rates of obesity and related diseases in such areas. METHODS: We obtained a list of all 1301 out-of-home eating outlets in Glasgow, UK, in 2003 and mapped these at unit postcode level. We categorised them into quintiles of area deprivation using the 2004 Scottish Index of Multiple Deprivation and computed mean density of types of outlet (restaurants, fast food restaurants, cafes and takeaways), and all types combined, per 1000 population. We also estimated odds ratios for the presence of any outlets in small areas within the quintiles. RESULTS: The density of outlets, and the likelihood of having any outlets, was highest in the second most affluent quintile (Q2) and lowest in the second most deprived quintile (Q4). Mean outlets per 1,000 were 4.02 in Q2, 1.20 in Q4 and 2.03 in Q5. With Q2 as the reference, Odds Ratios for having any outlets were 0.52 (CI 0.32–0.84) in Q1, 0.50 (CI 0.31 – 0.80) in Q4 and 0.61 (CI 0.38 – 0.98) in Q5. Outlets were located in the City Centre, West End, and along arterial roads. CONCLUSION: In Glasgow those living in poorer areas are not more likely to be exposed to out-of-home eating outlets in their neighbourhoods. Health improvement policies need to be based on empirical evidence about the location of fast food outlets in specific national and local contexts, rather than on popular 'factoids'

High frequency oscillator comprising cointegrated thin film resonator and active device

A cointegrated high frequency oscillator including a thin film resonator and activedevices formed on the same semiconductor substrate and by a process which is compatible with formation of both the thin film resonator and the active devices. The processes utilized in formation of the thin film resonator are adapted to microelectronic processing techniques such that the steps of formation of the active devices and the thin film resonator can be intermixed to the degree necessary to allow, for example, the metallization layers to serve as elements both of the active devices and the thin film resonator

Performance Analysis and Optimization of Asynchronous Circuits Produced by Martin Synthesis

We present a method for analyzing the timing performance of asynchronous circuits, in particular, those derived by program transformation from concurrent programs using the synthesis approach developed by Martin. The analysis method produces a performance metric (related to the time needed to perform an operation) in terms of the primitive gate delays of the circuit. Because the gate delays are functions of transistor sizes, the performance metric can be optimized with respect to these sizes. For a large class of asynchronous circuits -- including those produced by the Martin synthesis -- these techniques produce the global optimum of the performance metric. A CAD tool has been implemented to perform this optimization

Automated Compilation of Concurrent Programs into Self-Timed Circuits

No abstract available

The nature and correlates of paid and unpaid work among service users of London Community Mental Health Teams

Aims Little is known about how the rates and characteristics of mental health service users in unpaid work, training and study compare with those in paid employment. Methods: From staff report and patient records, 1353 mental health service users of seven Community Mental Health Teams in two London boroughs were categorised as in paid work, unpaid vocational activity or no vocational activity. Types of work were described using Standard Occupational Classifications. The characteristics of each group were reported and associations with vocational status were explored. Results: Of the sample, 5.5% were in paid work and 12.7% were in unpaid vocational activity, (including 5.3% in voluntary work and 8.1% in study or training). People in paid work were engaged in a broader range of occupations than those in voluntary work and most in paid work (58.5%) worked part-time. Younger age and high educational attainment characterised both groups. Having sustained previous employment was most strongly associated with being in paid work. Conclusions: Rates of vocational activity were very low. Results did not suggest a clear clinical distinction between those in paid and unpaid activity.The motivations for and functions of unpaid work need further research