Six Degrees of Freedom Control with Each Hand?

For some time man has made six degree of freedom inputs to a pair of dextrous manipulators using both hands simultaneously by the use of the master/slave concept. The advent of the microprocessor has the potential to make the master/slave concept redundant by replacing the master with a mathematical model. All spacecraft to date, including the space shuttle, that were flown in six degrees of freedom were controlled by using both hands, the left hand controlling translation and the right rotation. Almost inevitably the same principle was applied to the CANADARM. At the instigation of NASA the development of a device whereby both translation and rotation could be combined allowing full control with one hand was developed. The development and testing of the device, and the extension of its application into spaceflight control are described. Also the concept of an adaptable workstation for multi-maniipulator and spacecraft flight control is discussed

The Early English passion play

This discussion challenges the common understanding that biblical drama in England was dominated by ‘mystery plays’, narrowly understood to be cycles of short pageants, by drawing attention to the evidence for large-scale Passion Plays comparable with those better known from France and Burgundy. In so doing, it makes no apology for standing on the shoulders of Peter Meredith's work on the N-Town manuscript, and with John Tailby on the texts and documents illustrating the variety of staging of religious drama across Europe, as well as Meg Twycross's work on devisor Felsted of London, all of which demonstrate that this material has been available in the public domain for some years. Just as the N-Town Plays were still believed in some quarters to come from Coventry as late as the mid-twentieth century, although Francis Douce knew they did not almost 150 years earlier, so too the domination of modern understandings about English mystery plays has remained wedded to the model of four ‘cycles’ promulgated in the 1970s, despite the accumulation of evidence to the contrary. Peter Meredith's edition of The ‘Passion Play’ from the N. Town Manuscript is now all but unobtainable, and the volumes of Records of Early English Drama are the chosen bedtime reading of few, so here we revisit some texts and records to explore afresh one aspect of an already shifted paradigm

The free energy difference between 3-point water models

This paper describes precise calculations to determine the free energy differences between 3-point models of liquid water, using the method of thermodynamic integration and molecular dynamics. For the three models considered in this study the order of thermodynamic stability at 300 K and 1 atm pressure is SPC/E > SPC > TIP3P. The magnitudes of these stabilities are quantified and an estimate of the precision of the values is made

Global imbalances: the perspective of the Bank of England.

In 2009, demand in the world’s major economies fell, relative to its pre-crisis trend, by around USD 2.5 trillion or 5 per cent of GDP. The financial crisis damaged virtually every country. Global imbalances helped to fuel the financial crisis. And today they threaten the sustainability of the recovery in global demand. Global imbalances are a reflection of today’s decentralised international monetary and financial system. All the main players around the world are rationally pursuing their own self interest. But the financial crisis has revealed that what makes sense for each player individually does not always make sense in aggregate. These actions had collective consequences. The main lesson from the crisis is the need to find better ways of ensuring the right collective outcome. Improved financial regulation will help to intermediate the flows associated with global imbalances. But the global economy will remain vulnerable to the risks associated with imbalances if they are not tackled at source. Two principles should underpin the way ahead. First, discussions should focus on the underlying disagreement about the right speed of adjustment to the real pattern of spending and hence the reduction in these imbalances. This discussion should be informed by countries’ ability to follow that path in a sustainable way. Second, many policies, in addition to changes in exchange rates, will be needed to reduce imbalances. If agreement is not reached on these two principles, at best there will be a weak world recovery; at worst, the seeds of the next financial crisis will be sown.

Our side of the mirror : the (re)-construction of 1970s’ masculinity in David Peace’s Red Riding

David Peace and the late Gordon Burn are two British novelists who have used a mixture of fact and fiction in their works to explore the nature of fame, celebrity and the media representations of individuals caught up in events, including investigations into notorious murders. Both Peace and Burn have analysed the case of Peter Sutcliffe, who was found guilty in 1981 of the brutal murders of thirteen women in the North of England. Peace’s novels filmed as the Red Riding Trilogy are an excoriating portrayal of the failings of misogynist and corrupt police officers, which allowed Sutcliffe to escape arrest. Burn’s somebody’s Husband Somebody’ Son is a detailed factual portrait of the community where Sutcliffe spent his life. Peace’s technique combines reportage, stream of consciousness and changing points of views including the police and the victims to produce an episodic non linear narrative. The result has been termed Yorkshire noir. The overall effect is to render the paranoia and fear these crimes created against a backdrop of the late 1970s and early 1980s. Peace has termed his novels as “fictions of the facts”. This paper will examine the way that Peace uses his account of Sutcliffe’s crimes and the huge police manhunt to catch the killer to explore the society that produced the perpetrator, victims and the police. The police officers represent a form of “hegemonic masculinity” but one that is challenged by the extreme misogyny, brutality, misery and degradation that surround them. This deconstruction of the 1970s male police officer is contrasted with the enormously popular figure of Gene Hunt from the BBC TV series Life on Mars

Optimizing the ratio of captures to trapping effort in a black rat Rattus rattus control programme in New Zealand

The ratio of captures to unit effort is an important cost/benefit measure for volunteer pest control programmes. We describe an experiment designed to investigate the use of pre-feeding and trap pulsing as possible means of increasing this ratio. In 20 traps locked-open and pre-fed with non-toxic pellets for five days, the same number of black rats was caught over the next 5 days as in 20 non pre-fed traps set for the whole 10 days (32 rats each). Allowing for successful traps being unavailable for an average of half a night each, the capture rate in the pre-fed traps was 47% over five days, more than double that in the non pre-fed traps set for twice as long (total 19% in 10 days)

A Bayesian spatial random effects model characterisation of tumour heterogeneity implemented using Markov chain Monte Carlo (MCMC) simulation

The focus of this study is the development of a statistical modelling procedure for characterising intra-tumour heterogeneity, motivated by recent clinical literature indicating that a variety of tumours exhibit a considerable degree of genetic spatial variability. A formal spatial statistical model has been developed and used to characterise the structural heterogeneity of a number of supratentorial primitive neuroecto-dermal tumours (PNETs), based on diffusionweighted magnetic resonance imaging. Particular attention is paid to the spatial dependence of diffusion close to the tumour boundary, in order to determine whether the data provide statistical evidence to support the proposition that water diffusivity in the boundary region of some tumours exhibits a deterministic dependence on distance from the boundary, in excess of an underlying random 2D spatial heterogeneity in diffusion. Tumour spatial heterogeneity measures were derived from the diffusion parameter estimates obtained using a Bayesian spatial random effects model. The analyses were implemented using Markov chain Monte Carlo (MCMC) simulation. Posterior predictive simulation was used to assess the adequacy of the statistical model. The main observations are that the previously reported relationship between diffusion and boundary proximity remains observable and achieves statistical significance after adjusting for an underlying random 2D spatial heterogeneity in the diffusion model parameters. A comparison of the magnitude of the boundary-distance effect with the underlying random 2D boundary heterogeneity suggests that both are important sources of variation in the vicinity of the boundary. No consistent pattern emerges from a comparison of the boundary and core spatial heterogeneity, with no indication of a consistently greater level of heterogeneity in one region compared with the other. The results raise the possibility that DWI might provide a surrogate marker of intra-tumour genetic regional heterogeneity, which would provide a powerful tool with applications in both patient management and in cancer research

Efficient Groundness Analysis in Prolog

Boolean functions can be used to express the groundness of, and trace grounding dependencies between, program variables in (constraint) logic programs. In this paper, a variety of issues pertaining to the efficient Prolog implementation of groundness analysis are investigated, focusing on the domain of definite Boolean functions, Def. The systematic design of the representation of an abstract domain is discussed in relation to its impact on the algorithmic complexity of the domain operations; the most frequently called operations should be the most lightweight. This methodology is applied to Def, resulting in a new representation, together with new algorithms for its domain operations utilising previously unexploited properties of Def -- for instance, quadratic-time entailment checking. The iteration strategy driving the analysis is also discussed and a simple, but very effective, optimisation of induced magic is described. The analysis can be implemented straightforwardly in Prolog and the use of a non-ground representation results in an efficient, scalable tool which does not require widening to be invoked, even on the largest benchmarks. An extensive experimental evaluation is givenComment: 31 pages To appear in Theory and Practice of Logic Programmin