Stochastic relaxation,Gibbs distributions and the Bayesian restoration of images*

We make an analogy between images and statistical mechanics systems. Pixel gray levels and the presence and orientation of edges are viewed as states of atoms or molecules in a lattice-like physical system. The assignment of an energy function in the physical system determines its Gibbs distribution. Because of the Gibbs distribution, Markov random field (MRF) equivalence, this assignment also determines an MRF image model. The energy function is a more convenient and natural mechanism for embodying picture attributes than are the local characteristics of the MRF. For a range of degradation mechanisms, including blurring, non-linear deformations, and multiplicative or additive noise, the posterior distribution is an MRF with a structure akin to the image model. By the analogy, the posterior distribution defines another (imaginary) physical system. Gradual temperature reduction in the physical system isolates low-energy states (‘annealing’), or what is the same thing, the most probable states under the Gibbs distribution. The analogous operation under the posterior distribution yields the maximum a posteriori (MAP) estimate of the image given the degraded observations. The result is a highly parallel ‘relaxation’ algorithm for MAP estimation. We establish convergence properties of the algorithm and we experiment with some simple pictures, for which good restorations are obtained at low signal-to-noise ratios.     

Leglislators,Social Policy and Action: The Case of ‘Dying with Dignity’

This paper describes a process of policy formation through the parliamentary committee system. The nature of a Victorian investigatory committee and its function as a medium for public consultation regarding complex social and ethical issues is explored. The Public Inquiry into ‘Options for Dying with Dignity’ is discussed as a case study. The Inquiry led to benchmark Australian legislation through the Medical Treatment Act 1988, as well as promoting significant changes in terminal palliative care.     

Gender differences in the use of high-variance strategies in tournament competition

We report on a series of experiments in which participants first completed a simple game of chance and then competed in a tournament based on a multiple cue probability learning task. The results show that men made riskier choices in the simple game of chance, but women adopted the high-variance strategy more frequently in the tournament. However, after controlling for differences in forecasting skill, we find no significant differences in the rates at which men and women adopted a high-variance strategy. Although altering the difficulty of the forecasting task produces differences in the rate at which participants selected the high-variance strategy, it did not produce a significant difference in the rate at which men and women selected the strategy. Thus, this paper suggests that although women are more risk-averse than men, women are no less likely to adopt a high-variance strategy in a tournament competition.     

The Fairness of Decision Rules

Prior work on resource allocation has generally considered only a small number of allocation rules, usually reflecting equity or equality. We use a scenario study to examine the effect of eight different allocation rules (past performance, future performance, rank, random draw, chance meetings, business need, personal need, and political reasons) on recipient reactions to the gain or loss of three different kinds of resources in an organizational setting. We find evidence that allocations based on past performance and random draw rules lead to the highest fairness perceptions and the lowest expectations that the decisions made will lead to intragroup conflict. However, fairness judgments are also influenced by a variety of other factors, such as the type of resource being allocated and whether the recipient is advantaged or disadvantaged relative to others in the workgroup (what we term the “egocentric interaction”). We discuss how our results might influence managers’ allocation decisions.     

A collaborative student affairs and faculty health assessment and intervention initiative

The authors describe a collaborative partnership forged between faculty and student affairs staff to improve student health at a large urban university. They examine skills and reward structures of each constituency and the stages of the collaboration in the context of 2 theoretical models. A comprehensive data collection and dissemination process in the campus community provided goals for the initial stage of the partnership, leading to implementation of campus initiatives that use the reciprocal skills of each stakeholder. Outcomes of the collaboration included (1) a working relationship between faculty and student affairs staff, (2) increased dialogue with high-level administrators, (3) more coordinated campus efforts to decrease high-risk drinking, (4) use of outcome measures for implementing and evaluating health programs, and (5) an opportunity for interdisciplinary research. The authors offer suggestions for implementing the process on other campuses.     

Comparison of ergonomic risk assessment outputs from Rapid Upper Limb Assessment and the Strain Index for tasks in automotive assembly plants

This paper compares the ergonomic risk assessment of a task for the upper extremities as determined by Rapid Upper Extremity Assessment (RULA) and the Strain Index (SI). The ergonomic risk to the upper extremities of 244 automotive assembly plant tasks were evaluated using RULA and SI. The outcomes of each tool were compared for each task. Results from this study provide practical insight into the methods used in each tool. This study compared only the ergonomic risk outputs from each tool; it does not pursue the question of which tool best predicts injury. The kappa score was 0.11, indicating little agreement between the outputs of the two tools. This is supported by the lack of monotonicity with a gamma score of 0.1. These results indicate that the risk assessment outcome of these two ergonomic assessment tools for the upper extremities do not agree.     

ASSESSMENT OF INTERPERSONAL FUNCTIONS: DEVELOPING MEASURES TO AID THE FUNCTIONAL FAMILY THERAPIST

One of the cornerstones of the functional family therapy model proposed by Alexander and Parsons (1982) is the assessment of interpersonal functions, which has traditionally been accomplished through intuition and clinical judgment. In this study, 109 college freshmen were recruited to evaluate the test-retest reliability of a videotaped scenario measure and a questionnaire designed to assess interpersonal functions. Subjects responded to both measures during an initial assessment phase and then again, during a second assessment phase, 2 weeks later. Pearson product-moment correlations and average agreement percentages indicate that both measures have adequate reliability. There were no sex differences, nor were subjects' responses related to a measure of social desirability.     

The Geometry of Terrorism

Terrorism in its purest form is self‐help by organized civilians who covertly inflict mass violence on other civilians. Pure sociology explains terrorism with its social geometry—its multidimensional location and direction in social space. Here I build on the work of Senechal de la Roche (1996) and propose the following geometrical model: Pure terrorism arises intercollectively and upwardly across long distances in multidimensional space. Yet because social distance historically corresponded to physical distance, terrorism often lacked the physical geometry necessary for its occurrence: physical closeness to civilians socially distant enough to attract terrorism. New technology has made physical distance increasingly irrelevant, however, and terrorism has proliferated. But technology also shrinks the social universe and sows the seeds of terrorism's destruction .