The Effect of Surface Roughness on Contact Fatigue Behavior Using Mesoscopic Approach

The effect of surface roughness on the contact fatigue was investigated in this study. To accomplish this goal, contact analysis based on the influence functions and the rectangular patch solutions was performed to obtain the subsurface stress. Mesoscopic multiaxial fatigue criterion is then applied to predict fatigue damage. Rainbow counting method and damage rule were used to evaluate the fatigue life under random loadings caused by the rough surface contact. As a result of the fatigue analysis, the relationship among the fatigue life, the crack initiation depth, and the surface roughness were revealed. It is observed that the fatigue life has hardly changed and a crack is initiated at subsurface for the surface with the surface roughness below a critical value. However, if the surface roughness exceeds the critical value, fatigue life is remarkably reduced and the site of crack initiation moves to the near surface.     

Early withdrawal from mental health treatment: Implications for psychotherapy practice.

[Correction Notice: An erratum for this article was reported in Vol 46(2) of Psychotherapy: Theory, Research, Practice, Training (see record 2009-08897-009). The fourth author’s name was mistakenly left out of the author byline and table of contents. The correct author listing for this article is presented in the erratum.] Despite more than 50 years of research on client attrition from therapy, obstacles to the delivery and success of treatments remain poorly understood, and effective methods to engage and retain clients in therapy are lacking. This article offers a review of the literature on attrition, highlighting the methodological challenges in effectively addressing the complex nature of this problem. Current interventions for reducing attrition are reviewed, and recommendations for implementing these interventions into psychotherapy practice are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A line-space analysis of light-field representations

We study how to build optimal light-field or plenoptic models. We quantify geometric errors in light-field representations and show how geometric error bounds directly affect rendering artifacts. Artifacts depend on how the light-field is parameterized, stored, reconstructed and rendered. We present the rendering artifacts and relate them to the presence of geometric errors in the four most common light-field implementations.We show how to optimize a light-field model. We take an arbitrary bounded object and construct the best possible representation using each of the four parameterizations. The best representation has the least geometric error bounds. We use two geometric errors, a positional and a directional error. We also quantify pixelation artifacts. Our analysis is useful to decide how to build a light-field model. It helps select a parameterization, build an optimal representation, and choose the samplings of the parameter spaces so that geometric errors and rendering artifacts are minimized.     

Possible amotivational effects following marijuana smoking under laboratory conditions.

Human participants earned money by responding on a progressive-ratio (PR) schedule (initial value $50) or received money without responding on a fixed-time (FT) schedule. During the session, participants could terminate the PR schedule and initiate an FT 200-s schedule. In Experiment 1, increases in monetary value produced increased number of responses, time spent, and money earned in the PR component. In Experiment 2, marijuana smoking produced potency-related reductions in the number of responses, time spent, and money earned in the PR component, effects that can be interpreted as amotivational. Increasing the monetary value of the reinforcer diminished the acute marijuana effects on PR responding, suggesting that marijuana exerted an effect primarily on reinforcers of a smaller magnitude. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Rehabilitation psychology and public health: Commonalities, barriers, and bridges.

Purpose: Those in rehabilitation and those in public health have worked to find a place in their respective disciplines. In this article, the author attempts to outline some of the commonalities inherent in the two areas, the barriers to joint work, and the bridges that may be able to allow a more comfortable interaction between the two. Conclusion: Practical realities in modern society have created the need for a closer bond among rehabilitation psychology, disability, and public health. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Microcomputer-based software to perform lease versus buy analysis

The primary purpose of this paper is to present a computerized lease-versus-buy program utilized by the Defense Contract Audit Agency to monitor defense contractor data processing hardware procurement. The main points of the paper shall pertain to the financial elements incorporated into the software, reports generated, and the resulting lease-versus-buy decision. Discussion of the lease-versus-buy process shall relate primarily to the procurement of data processing equipment. The approach taken in the lease-versus-buy decision process for procuring data processing equipment is basically no different from the methodology used in acquiring other types of capital equipment. Hence, the proposed microcomputer-based program used to performed lease-versus-buy analysis for data processing equipment is suitable for industrial equipment procurement, as well.     

Risk aversion in rats (Rattus norvegicus) under varying levels of resource availability.

Five male Wistar rats chose between a certain prospect and an uncertain prospect having equal expected value under varying levels of resource (water) availability. In contrast to results found with granivorous birds and common shrews (Sorex araneus), the rats did not switch from risk aversion (choosing the certain prospect) to risk preference (choosing the uncertain prospect) as resource availability varied from surplus to deficit, even though deficits were maintained for extended periods of time. Rather, Ss displayed an approximately constant level of risk aversion throughout. Explanations for these differences are offered in terms of procedural differences between this and earlier studies and in terms of differential behavioral patterns of relatively large organisms with large internal resource stores relative to their daily resource requirements. (15 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)