A systematic optimization approach for the calibration of parallel kinematics machine tools by a laser tracker

Parallel kinematics machine has attracted attention as machine tools because of the outstanding features of high dynamics and high stiffness. Although various calibration methods for parallel kinematics machine have been studied, the influence of inaccurate motion of joints is rarely considered in these studies. This paper presents a high-accuracy and high-effective approach for calibration of parallel kinematics machine. In the approach, a differential error model, an optimized model and a statistical method are combined, and the errors of parallel kinematics machine due to inaccurate motion of joints can be reduced by this approach. Specifically, the workspace is symmetrically divided into four subspaces, and a measurement method is suggested by a laser tracker to require the actual pose of the platform in these subspaces. An optimized model is proposed to solve the kinematic parameters in symmetrical subspaces, and then arithmetical mean method is proposed to calculate the final kinematic parameter. In order to achieve the global optimum quickly and precisely, the initial value of the optimal parameter is directly solved based on the differential error model. The proposed approach has been realized on the developed 5-DOF hexapod machine tool, and the experiment result proves that the presented method is very effective and accurate for the calibration of the hexapod machine tool.     

油罐清洁连体作业服的开发和工效学评价

根据油罐清洁环境和工作要求,以满足防护性为前提,通过功能性结构设计达到服装的合体性与舒适性.利用现有面料设计制作新型油罐清洁连体作业服,特别是腰部、膝部等大幅活动部位以及衣袖裤脚的收口处.通过人体工效学实验检验,5 cm最大打开量的腰部弹性折裥可使新型服装在直立或直身下蹲时保持合体性,轻度弯腰达2.5 cm平均打开量,弯腰抱膝等大幅动作时拉伸服装达4.6 cm的平均量.脚口和袖口的三角插片与拉链收口设计同常规橡筋收口服装在该处的皮肤覆盖程度无显著差异,并可提高舒适性.新型连体服装在所有的实验设计部位的人体活动限制均小于现有连体服,使人体肢体活动更加灵活.为提供集功能性、防护性与合体性、舒适性为一体的油罐清洁连体作业服提供参考.     

当代官场小说权利追逐过程中人性的异化

从官场人物在向“物欲”妥协过程中灵魂被撕扯的痛苦和看守精神家园付出的物质代价两个方面，论述了人性在人的物质需求与精神需求的碰撞冲突中被异化的过程。     

Prevalence and predictors of posttraumatic stress in women undergoing an ovarian cancer investigation.

This study assessed posttraumatic stress disorder (PTSD) in women being investigated for an ovarian cancer diagnosis to determine prevalence and factors predicting PTSD in these patients. Participants (N = 75) were recruited from the Princess Margaret Hospital in Toronto, Ontario, after their initial clinic appointment and given a prediagnostic assessment that included measures of PTSD, depression, stress and pain. One month later, patients received an identical postdiagnostic assessment. No cases of clinical PTSD were detected, although 13.6% of participants were identified with subsyndromal PTSD. Multiple regression analyses showed that those participants reporting significant baseline depressive symptoms, definitively diagnosed with ovarian cancer, and with shorter treatment wait times were more likely to have a significant increase in PTSD symptoms. Supportive interventions aimed at reducing PTSD symptoms, launched prior to an ovarian cancer diagnosis, might optimally be directed at patients with baseline depressive symptoms and those with shorter treatment wait times. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Interaction-dominant dynamics in human cognition: Beyond 1/?α fluctuation.

It has been suggested that human behavior in general and cognitive performance in particular emerge from coordination between multiple temporal scales. In this article, we provide quantitative support for such a theory of interaction-dominant dynamics in human cognition by using wavelet-based multifractal analysis and accompanying multiplicative cascading process on the response series of 4 different cognitive tasks: simple response, word naming, choice decision, and interval estimation. Results indicated that the major portion of these response series had multiplicative interactions between temporal scales, visible as intermittent periods of large and irregular fluctuations (i.e., a multifractal structure). Comparing 2 component-dominant models of 1/fα fluctuations in cognitive performance with the multiplicative cascading process indicated that the multifractal structure could not be replicated by these component-dominant models. Furthermore, a similar multifractal structure was shown to be present in a model of self-organized criticality in the human nervous system, similar to a spatial extension of the multiplicative cascading process. These results illustrate that a wavelet-based multifractal analysis and the multiplicative cascading process form an appropriate framework to characterize interaction-dominant dynamics in human cognition. This new framework goes beyond the identification of 1/fα power laws and non-Gaussian distributions in response series as used in previous studies. The present article provides quantitative support for a paradigm shift toward interaction-dominant dynamics in human cognition. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Review of Emotion, character, and responsibility.

Reviews the book, Emotion, character, and responsibility by John Sabini and Maury Silver (see record 1999-02229-000). In this compilation of previously published essays, Sabini and Silver take on one of the more vexing issues in contemporary psychology of emotion—the relationship between emotions (which are typically experienced as unchosen) and responsibility. The book examines such human emotional experiences as sympathy, sincerity, loyalty and duty, shame, guilt, and embarrassment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Gender differences in personality traits across cultures: Robust and surprising findings.

Secondary analyses of Revised NEO Personality inventory data from 26 cultures (N =23,031) suggest that gender differences are small relative to individual variation within genders; differences are replicated across cultures for both college-age and adult samples, and differences are broadly consistent with gender stereotypes: Women reported themselves to be higher in Neuroticism, Agreeableness, Warmth, and Openness to Feelings, whereas men were higher in Assertiveness and Openness to Ideas. Contrary to predictions from evolutionary theory, the magnitude of gender differences varied across cultures. Contrary to predictions from the social role model, gender differences were most pronounced in European and American cultures in which traditional sex roles are minimized. Possible explanations for this surprising finding are discussed, including the attribution of masculine and feminine behaviors to roles rather than traits in traditional cultures. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Using Hybrid Automata to Support Human Factors Analysis in a Critical System

A characteristic that many emerging technologies and interaction techniques have in common is a shift towards tighter coupling between human and computer. In addition to traditional discrete interaction, more continuous interaction techniques, such as gesture recognition, haptic feedback and animation, play an increasingly important role. Additionally, many supervisory control systems (such as flight deck systems) already have a strong continuous element. The complexity of these systems and the need for rigorous analysis of the human factors involved in their operation leads us to examine formal and possibly automated support for their analysis. The fact that these systems have important temporal aspects and potentially involve continuous variables, besides discrete events, motivates the application of hybrid systems modelling, which has the expressive power to encompass these issues. Essentially, we are concerned with human-factors related questions whose answers are dependent on interactions between the user and a complex, dynamic system.In this paper we explore the use of hybrid automata, a formalism for hybrid systems, for the specification and analysis of interactive systems. To illustrate the approach we apply it to the analysis of an existing flight deck instrument for monitoring and controlling the hydraulics subsystem.