Analytical model for approximating node throughputs in wireless mesh networks

This paper describes an analytical model and an associated algorithm for assessing the throughputs of each host in wireless mesh networks (WMNs). It provides a framework for studying WMNs, particularly when the performance and parameters in multiple protocol layers have to be jointly evaluated and optimized. From the point of the implementation, a simple recursive formula with N ? 1 iterations is used to obtain the throughput performance of N node WMNs. The produced expressions offer insights into understanding the performance of the individual nodes without referring to a specific medium access control layer or physical layer technology. The model serves as a general tool for capturing the characteristics of the WMNs. Using the model, the complexity of cross‐layer studies is reduced, thus allowing researchers to focus on the modelling of other associated layers. The paper explains the rationale behind the model and provides examples of scenarios for which it is suitable. It is validated using discrete event simulations in the OPNET network simulator. Copyright © 2012 John Wiley & Sons, Ltd.     

Dual agency, dual relationships, boundary crossings, and associated boundary violations: a survey of military and civilian psychiatrists

We hypothesized that psychiatrists with high dual-agency potential (military and health maintenance organization [HMO] psychiatrists) were more likely than non-HMO civilian psychiatrists to engage in dual relationships, report pressures to do so, participate in other general boundary-crossing activities, and report associated counter-therapeutic outcomes (boundary violations). Ninety military and 191 demographically matched civilian psychiatrists reported the number of boundary-crossing activities (including dual relationships) and associated counter-therapeutic outcomes in the preceding year with adult patients. Military and HMO psychiatrists reported greater external pressures than non-HMO civilian psychiatrists to engage in dual relationships; however, all three groups were similar in their reported numbers of dual relationships. The reported boundary-crossing activities and dual relationships studied here are not necessarily associated with reported boundary violations. The relative risk of a particular boundary crossing associating with harm to a patient likely depends on the therapeutic context and should be determined on a case-by-case basis.     

Social Comparison of Power: Interpersonal Versus Intergroup Effects.

The authors investigated why people change power distributions. Social comparison theory predicts that people strive to be positively distinct in power from comparison others. However, if equal-power others are categorized as in-group members and different-power others as out-group members, people may try to make their group more powerful than the out-group. Seventy participants performed a decision-making task in a hierarchical structure. Another person had equal or more power; a third had equal or less power than the participant. Participants indicated they shared group membership more with equal-power than unequal-power others. However, power differences increased more with equally than with less powerful others. Thus, group differentiation does not necessarily suppress interpersonal comparison and involves striving for interpersonal positive distinctiveness. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An adaptive spatial–spectral total variation approach for Poisson noise removal in hyperspectral images

Poisson distributed noise, such as photon noise, is an important noise source in multi- and hyperspectral images. We propose a variational-based denoising approach that accounts the vectorial structure of a spectral image cube, as well as the Poisson distributed noise. For this aim, we extend an approach initially developed for monochromatic images, by a regularisation term, which is spectrally and spatially adaptive and preserves edges. In order to take the high computational complexity into account, we derive a split Bregman optimisation for the proposed model. The results show the advantages of the proposed approach compared with a marginal approach on synthetic and real data.