Video image processing with the Sonic architecture

Current industrial video-processing systems use a mixture of high-performance workstations and application-specific integrated circuits. However, video image processing in the professional broadcast environment requires more computational power and data throughput than most of today's general-purpose computers can provide. In addition, using ASICs for video image processing is both inflexible and expensive. Configurable computing offers an appropriate alternative for broadcast video image editing and manipulation by combining the flexibility, programmability, and economy of general-purpose processors with the performance of dedicated ASICs. Sonic is a configurable computing system that performs real-time video image processing. The authors describe how it implements algorithms for two-dimensional linear transforms, fractal image generation, filters, and other video effects. Sonic's flexible and scalable architecture contains configurable processing elements that accelerate software applications and support the use of plug-in software     

Speeding drivers' attitudes and perceptions of speed cameras in rural England

There is evidence that excessive speed leads to an increased frequency and severity of road traffic accidents, but it is not clear how speeds may be reduced. To increase understanding of why drivers exceed the speed limits, the views of a sample of road users who had been prosecuted for exceeding the speed limit in the rural county of Norfolk England were sought. Respondents were categorised into a four group driver typology comprising conformers (those who report they never exceed limits) deterred drivers (those put off speeding by the presence of cameras), manipulators (those who slow only at camera locations) and defiers (those who exceed limits regardless of cameras), and the consistency of opinions was compared between the groups. Speeding was perceived as widespread and normal, and many drivers resented camera enforcement. Indeed, some respondents considered that cameras in themselves caused dangerous driving. For many drivers, the prosecution experience resulted in distress, anger and anti-camera sentiments, predominantly because they expressed the belief that they were more skilled than other drivers. It was also apparent that many respondents displayed a lack of awareness of the link between speed and collisions. Conformers were the least likely to state that the prosecution had deterred them from further speeding behaviour, possibly because they perceived themselves as already law-abiding. The deterred drivers were most likely to express intentions to avoid further speeding and their speeding incident was found to be most likely to be accidental. Manipulators and defiers tended to report that they had deliberately chosen to infringe the speed limits. Manipulators often acknowledged that their style of driving was dangerous; however, they failed to link this to their own behaviour. It was evident that many defiers and manipulators did not perceive speeding as a serious traffic law violation. Possible implications for road safety initiatives are discussed and recommendations are given for specifically targeting different driver types.     

Scenario-Based Methods for Evaluating Collaborative Systems

Evaluating collaborative systems remains a significant challenge. Most evaluation methods approach the problem from one of two extremes: focused evaluation of specific system features, or broad ethnographic investigations of system use in context. In this paper, we develop and demonstrate a middle ground for evaluation: explicit reflections on scenarios of system use coupled with analysis of the consequences of these use scenarios, represented as claims. Extending prior work in scenario-based design and claims analysis, we develop a framework for a multi-perspective, multi-level evaluation of collaborative systems called SWIMs: scenario walkthrough and inspection methods. This approach is centered on the capture, aggregation, and analysis of users’ reflections on system support for specific scenarios. We argue that this approach not only provides the contextual sensitivity and use centricity of ethnographic techniques, but also sufficient structure for method replication, which is common to more feature-based evaluation techniques. We demonstrate with an extensive field study how SWIMs can be used for summative assessment of system performance and organizational contributions, and formative assessment to guide system and feature re-design. Results from the field study provide preliminary indications of the method’s effectiveness and suggest directions for future research.     

The effects of a nitrification inhibitor on leaching losses and recovery of mineralized nitrogen by a wheat crop after ploughing-in temporary leguminous pastures

The effect of a nitrification inhibitor on the accumulation of ammonium (NH ₄ ⁺ -N) and nitrate (NO ₃ ^- -N) in the profile was investigated in two field experiments in Canterbury, New Zealand after the ploughing of a 4-year old ryegrass/white clover pasture in early (March) and late autumn (May). Nitrate leaching over the winter, and yield and N uptake of a following wheat crop were also assessed.The accumulation of N in the soil profile by the start of winter was greater in the March fallow (76–140 kg N ha^–1) than in the May fallow treatment (36–49 kg N ha^–1). The nitrification inhibitor dicyandiamide (DCD) did not affect the extent of net N mineralization, but it inhibited nitrification when applied to pasture before ploughing, especially at its depth of incorporation (100–200 mm). Nitrification inhibition in spring was greater when DCD was applied in May rather than in March due to its reduced degradation over the winter.Cumulative nitrate leaching losses were substantial from the March fallow treatment in both years (about 100 kg N ha^–1). A delay in the cultivation of pasture and the application of DCD both reduced nitrate leaching losses. When leaching occurred early in the winter (in 1991), losses were less when pasture was cultivated in May (2 kg N ha^–1) than when DCD was applied to pasture cultivated in March (68 kg N ha^–1). When leaching occurred late in the winter (in 1992), similar losses were measured from pasture cultivated in May (49 kg N ha^–1) and from DCD-treated pasture cultivated in March (57 kg N ha^–1).Grain harvest yield and N uptake of the following spring wheat crop were generally unaffected by the size of the N leaching loss over the winter. This was due to the high N fertility of the soil after four years of a grazed leguminous pasture.     

Labor markets and regional transportation improvements: the case of high-speed trains An introduction and review

Labor market issues are reviewed in terms of mobility and policy resulting from transportation improvements. Research on Meso level regional adjustment versus micro level search processes are reviewed. A spatial interaction approach to assessing changes in regional access and regional industrial mix is outlined. Hypotheses with respect to transportation and labor markets are discussed. Empirical evidence of the impact of high-speed rail on labor markets and their structure is reviewed. Conclusions are drawn and new research questions are identified. Received: May 1996 / Accepted in revised form: February 1997     

Treatment implications of psychological assessment.

Presents some conceptual foundations and methods of enhancing the power of treatment decisions through psychological assessment. Individual articles discuss the identification of clients' behavior problems, a constructional approach to treatment, goal-centered and contextual assessment, the assessment of causal factors affecting clients' behavior problems, and the evaluation and refinement of ongoing therapy. The series proposes that treatment programs will be more effective if based on psychological assessment data and time-series assessment strategies, implemented throughout the assessment-treatment process. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Fast feedback control of a high temperature fusion plasma

One of the most promising approaches to achieving fusion of the light elements, as a potential large-scale energy source for the next century, is based on the magnetic confinement of an ionised high temperature plasma. Most of the current research in magnetic confinement makes use of toroidal plasma configurations in experiments known as tokamaks. Theoretical results have predicted that the characteristics of a tokamak plasma can be made more favourable to fusion if the cross-section of the plasma is appropriately shaped. However, the accurate generation of such plasmas, and the real-time control of their position and shape, represents a demanding problem involving the simultaneous adjustment of the currents through several control coils on time scales as short as a few tens of microseconds. In this paper, we present results from the first use of neural networks for the control of the high temperature plasma in a tokamak fusion experiment. This application requires the use of fast hardware, for which we have developed a fully parallel custom implementation of a multilayer perceptron, based on a hybrid of digital and analogue techniques. Our results demonstrate that the network is indeed capable of fast plasma control in accordance with the predictions of software simulations.     

Balance sheet of phosphorus,sulphur and potassium in a long-term grazed pasture supplied with superphosphate

A balance sheet of P, S and K was constructed for a long-term trial which investigates the effects of three rates of superphosphate (9% P, 11% S) on pasture production on border-strip irrigated land grazed with sheep. A balance sheet of the inputs and outputs of P, S and K to the trial over a 38 year period showed that of the nutrients applied in fertiliser, only 51–59% of the P and 15–31% of the S were retained in the soil. Small amounts were lost in animal products (4–19% of the applied nutrients) but major losses were attributed to runoff of P as particulate matter (dung and soil particles) during irrigation and leaching of sulphate-S during irrigation. Losses of K from the site were small and had no effect on total soil K content. The distribution of soil nutrients across the border-strips was also investigated. The results showed that the concentrations of total soil P and S and exchangeable K were significantly greater at the sides of the irrigation borders than in the main strip area of pasture. This was caused by deposition of a disproportionate amount of dung and urine (and therefore nutrients) on the levees where the sheep tended to camp. It was calculated that with increasing superphosphate rates greater amounts of P were transferred to the levees due to the increased amounts of P being recycled via the animals (as a result of increased herbage P concentration, pasture production and stocking rate).