Holographic d-wave superconductors

We construct top down models for holographic d-wave superfluids in which the order parameter is a charged spin two field in the bulk. Close to the transition temperature the condensed phase can be captured by a charged spin two field in an R-charged black hole background (downstairs picture) or equivalently by specific graviton perturbations of a spinning black brane (upstairs picture). We analyse the necessary conditions on the mass and the charge of the spin two field for a condensed phase to exist and we discuss the competition of the d-wave phase with other phases such as s-wave superfluids.Comment: 58 pages, 7 figure

Childhood predictors of criminal offending: results from a 19-year longitudinal epidemiological study of boys

Objective: To examine the relative contribution of hyperactivity, conduct, and emotional problems in predicting criminal offending. Method: In all, 173 boys aged 6 to 8 years (assessed for hyperactivity, conduct, and emotional problems) were followed up 19 years later by examining criminal offense histories. Results: Significant main effects for total and violent convictions were found, the strongest being for violent criminal offenses. Conduct problems predicted general offending (irrespective of the type of conviction), whereas emotional problems were the single best predictor of violent convictions. Hyperactivity was not a significant predictor in the models. Conclusion: The findings provide insight into the developmental mechanisms that mediate criminal behavior by showing that childhood emotional problems independently contribute to the risk of violent offending in later

Team-oriented process programming

Team-oriented process programming promises to provide significant support for the planning, directing, and controlling of software engineering projects. In this paper we apply process programming to software engineering teams and show how this can provide powerful new capabilities for the management of software projects. We identify key issues which must be addressed to apply process programming to teams, and present our vision for team-oriented process programming

Graph models for reachability analysis of concurrent programs

Reachability analysis is an attractive technique for analysis of concurrent programs because it is simple and relatively straightforward to automate, and can be used in conjunction with model-checking procedures to check for application-specific as well as general properties. Several techniques have been proposed differing mainly on the model used; some of these propose the use of flowgraph based models, some others of Petri nets.This paper addresses the question: What essential difference does it make, if any, what sort of finite-state model we extract from program texts for purposes of reachability analysis? How do they differ in expressive power, decision power, or accuracy? Since each is intended to model synchronization structure while abstracting away other features, one would expect them to be roughly equivalent.We confirm that there is no essential semantic difference between the most well known models proposed in the literature by providing algorithms for translation among these models. This implies that the choice of model rests on other factors, including convenience and efficiency.Since combinatorial explosion is the primary impediment to application of reachability analysis, a particular concern in choosing a model is facilitating divide-and-conquer analysis of large programs. Recently, much interest in finite-state verification systems has centered on algebraic theories of concurrency. Yeh and Young have exploited algebraic structure to decompose reachability analysis based on a flowgraph model. The semantic equivalence of graph and Petri net based models suggests that one ought to be able to apply a similar strategy for decomposing Petri nets. We show this is indeed possible through application of category theory

Children’s views of their teacher’s role in helping them learn mathematics

This paper reports on data from 183 nine-to eleven-year old children attending six Waikato schools. An analysis is provided of children’s responses to a question about their teacher’s role in helping them learn mathematics. Four major roles were identified, including mentor, classroom manager, transmitter of information, and arbiter of decisions. The implications for students’ mathematics learning of viewing their teacher in each of these roles are then discussed. The importance for teachers of recognising the ways they are perceived by their students is also considered

THE INFLUENCE OF TECHNOLOGICAL PROGRESS ON THE LONG RUN FARM LEVEL ECONOMICS OF SOIL CONSERVATION

The complementary interaction between topsoil depth and technical progress for winter wheat in the Palouse region was found to strengthen the long run payoff to conservation tillage. Nonetheless, conservation tillage was found to be competitive with conventional tillage only if its current yield disadvantages were eliminated. Conservation tillage was relatively more competitive on shallower topsoils and for longer planning horizons. Short-term subsidies coupled with research directed towards reducing the cost and yield disadvantages of conservation tillage in the Palouse were advocated to maintain long-term soil productivity.Land Economics/Use, Research and Development/Tech Change/Emerging Technologies,

RURAL-TO-URBAN WATER TRANSFERS: MEASURING DIRECT FOREGONE BENEFITS OF IRRIGATION WATER UNDER UNCERTAIN WATER SUPPLIES

Irrigation water from a southeastern Colorado county has been sold to distant municipalities. The county's junior water right delivered limited and uncertain water supplies which were used on relatively poor soils. The ability of water markets to allocate water to the highest-valued use was addressed by assessing the direct foregone benefits of the transfer using deterministic and discrete stochastic sequential (DSSP) programming models. Crop mix predicted by the DSSP followed observed regional patterns. The DSSP was thus used to derive regional water demand from which foregone value was estimated. Direct regional foregone agricultural benefits were relatively low-due to uncertain water supplies and unproductive soils-indicating the market selected a low-valued supply for transfer.Resource /Energy Economics and Policy,

System identification, time series analysis and forecasting:The Captain Toolbox handbook.

CAPTAIN is a MATLAB compatible toolbox for non stationary time series analysis, system identification, signal processing and forecasting, using unobserved components models, time variable parameter models, state dependent parameter models and multiple input transfer function models. CAPTAIN also includes functions for true digital control

Students' perspectives on the nature of mathematics

This paper reports on one small component of a much larger study that explored the perspectives of students towards mathematics learning. Students were asked “What do you think maths is all about?” Some students responded in terms of mathematical content. Others commented on learning in general, or on problem-solving in particular. Some students talked about the usefulness of mathematics for everyday life. An overwhelming number of students answered the question by talking about the importance of mathematics for the future