Consistency of Markov chain quasi-Monte Carlo on continuous state spaces

The random numbers driving Markov chain Monte Carlo (MCMC) simulation are usually modeled as independent U(0,1) random variables. Tribble [Markov chain Monte Carlo algorithms using completely uniformly distributed driving sequences (2007) Stanford Univ.] reports substantial improvements when those random numbers are replaced by carefully balanced inputs from completely uniformly distributed sequences. The previous theoretical justification for using anything other than i.i.d. U(0,1) points shows consistency for estimated means, but only applies for discrete stationary distributions. We extend those results to some MCMC algorithms for continuous stationary distributions. The main motivation is the search for quasi-Monte Carlo versions of MCMC. As a side benefit, the results also establish consistency for the usual method of using pseudo-random numbers in place of random ones.Comment: Published in at http://dx.doi.org/10.1214/10-AOS831 the Annals of Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical Statistics (http://www.imstat.org

Distribution of human waste samples in relation to sizing waste processing in space

Human waste processing for closed ecological life support systems (CELSS) in space requires that there be an accurate knowledge of the quantity of wastes produced. Because initial CELSS will be handling relatively few individuals, it is important to know the variation that exists in the production of wastes rather than relying upon mean values that could result in undersizing equipment for a specific crew. On the other hand, because of the costs of orbiting equipment, it is important to design the equipment with a minimum of excess capacity because of the weight that extra capacity represents. A considerable quantity of information that had been independently gathered on waste production was examined in order to obtain estimates of equipment sizing requirements for handling waste loads from crews of 2 to 20 individuals. The recommended design for a crew of 8 should hold 34.5 liters per day (4315 ml/person/day) for urine and stool water and a little more than 1.25 kg per day (154 g/person/day) of human waste solids and sanitary supplies

Differential Entropy on Statistical Spaces

We show that the previously introduced concept of distance on statistical spaces leads to a straightforward definition of differential entropy on these statistical spaces. These spaces are characterized by the fact that their points can only be localized within a certain volume and exhibit thus a feature of fuzziness. This implies that Riemann integrability of relevant integrals is no longer secured. Some discussion on the specialization of this formalism to quantum states concludes the paper.Comment: 4 pages, to appear in the proceedings of the joint meeting of the 2nd International Conference on Cybernetics and Information Technologies, Systems and Applications (CITSA 2005) and the 11th International Conference on Information Systems Analysis and Synthesis (ISAS 2005), to be held in Orlando, USA, on July 14-17, 200

Gold-free GaAs/GaAsSb heterostructure nanowires grown on silicon

Growth of GaAs/GaAsSb heterostructurenanowires on silicon without the need for gold seed particles is presented. A high vertical yield of GaAsnanowires is first obtained, and then GaAsₓSb₁ˍₓ segments are successfully grown axially in these nanowires. GaAsSb can also be integrated as a shell around the GaAs core. Finally, two GaAsSb segments are grown inside a GaAsnanowire and passivated using an AlₓGa₁ˍₓAs shell. It is found that no stacking faults or twin planes occur in the GaAsSb segments.Part of this work was funded by the Swedish Foundation for Strategic Research SSF, the Swedish Research Council VR, and the Knut and Alice Wallenberg Foundation

Results from the Scottish report card on physical activity for children and youth

The Active Healthy Kids Scotland Report Card aims to consolidate existing evidence, facilitate international comparisons, encourage more evidence-informed physical activity and health policy, and improve surveillance of physical activity. Application of the Active Healthy Kids Canada Report Card process and methodology to Scotland, adapted to Scottish circumstances and availability of data. The Active Healthy Kids Scotland Report Card 2013 consists of indicators of 7 Health Behaviors and Outcomes and 3 Influences on Health Behaviors and Outcomes. Grades of F were assigned to Overall Physical Activity, Sedentary Behavior (recreational screen time), and Obesity Prevalence. A C was assigned to Active Transportation and a D- was assigned to Diet. Two indicators, Active and Outdoor Play and Organized Sport Participation, could not be graded. Among the Influences, Family Influence received a D, while Perceived Safety, Access, and Availability of Spaces for Physical Activity and the National Policy Environment graded more favorably with a B. The Active Healthy Kids Canada process and methodology was readily generalizable to Scotland. The report card illustrated low habitual physical activity and extremely high levels of screen-based sedentary behavior, and highlighted several opportunities for improved physical activity surveillance and promotion strategies

Social Identity and Social Exchange: Identification, Support, and Withdrawal from the Job

Integrating insights from the social exchange perspective and the social identity perspective on the psychological relationship between the individual and the organization, we propose that evaluations of the support received from the organization and its representatives, and organizational identification interact in predicting withdrawal from the job. Specifically, the relationship of support with withdrawal is proposed to be weaker the stronger employees identify with the organization. This prediction was confirmed in two samples focusing on different operationalizations of support and withdrawal. Sample 1 concerned the interaction of organizational support and organizational identification in predicting turnover intentions, Sample 2 concerned the prediction of absenteeism from supervisor support and organizational identification. We conclude that the present study yields promising first evidence that may lay the basis for further integration of social exchange and social identity analyses of organizational behavior.Organizational behavior;Organizational identification;Organizational support;Social identity

Conformal entropy for generalised gravity theories as a consequence of horizon properties

We show that microscopic entropy formula based on Virasoro algebra follows from properties of stationary Killing horizons for Lagrangians with arbitrary dependence on Riemann tensor. The properties used are consequence of regularity of invariants of Riemann tensor on the horizon. Eventual generalisation of these results to Lagrangians with derivatives of Riemann tensor, as suggested by an example treated in the paper, relies on assuming regularity of invariants involving derivatives of Riemann tensor. This assumption however leads also to new interesting restrictions on metric functions near horizon.Comment: 9 pages, appendix adde