A computer simulation approach to evaluating bowl versus inverted bowl assembly line arrangement with variable operation times

A computer simulation model was used to evaluate a bowl versus inverted bowl assembly line arrangement for normal and exponential distributions and variances equal to 1 and 16. The model was developed on the basis of a realistic case problem and applied to a six-station assembly line. The results show that the inverted bowl is superior to the bowl arrangement for a normal distribution in terms of the total elapsed time evaluation criterion; however, with an exponential distribution, the bowl was found better than the inverted bowl for the same criterion. On the basis of the average percentage of working time and the average time in the system evaluation criteria, the bowl was found superior to the inverted bowl for a normal distribution. Similar results were obtained for an exponential distribution with a variance equal to 1, but no definitive inference could be made with a variance equal to 16.     

Verbal working memory and language production: Common approaches to the serial ordering of verbal information.

[Correction Notice: An erratum for this article was reported in Vol 136(3) of Psychological Bulletin (see record 2010-07936-010). In the article “Verbal Working Memory and Language Production: Common Approaches to the Serial Ordering of Verbal Information” by Daniel J. Acheson and Maryellen C. MacDonald (Psychological Bulletin, 2009, Vol. 135, No. 1, pp. 50–68), the initial sentence of the text of the article (p. 50) contains an error. The first name of the researcher Andrew W. Ellis was listed incorrectly. The sentence should read as follows: Nearly 30 years ago, Andrew W. Ellis (1980) observed that errors on tests of verbal working memory (WM) paralleled those that occur naturally in speech production.] Verbal working memory (WM) tasks typically involve the language production architecture for recall; however, language production processes have had a minimal role in theorizing about WM. A framework for understanding verbal WM results is presented here. In this framework, domain-specific mechanisms for serial ordering in verbal WM are provided by the language production architecture, in which positional, lexical, and phonological similarity constraints are highly similar to those identified in the WM literature. These behavioral similarities are paralleled in computational modeling of serial ordering in both fields. The role of long-term learning in serial ordering performance is emphasized, in contrast to some models of verbal WM. Classic WM findings are discussed in terms of the language production architecture. The integration of principles from both fields illuminates the maintenance and ordering mechanisms for verbal information. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Rating formats and rater training redux: A context-specific approach for enhancing the effectiveness of performance management.

In this paper, we critically examine previous research on rating formats and rater training in the context of performance appraisal. Historically, the goal of this body of research has been to search for ways of maximizing the psychometric quality of performance evaluation data. Our central thesis is that there are a number of avenues for broadening this research. Accordingly, we propose a conceptual model that hopefully serves as a conceptual framework for future work in these 2 traditional performance appraisal research streams. For example, both rating formats and rater training research may be useful for facilitating and improving the feedback and employee development process, as well as reducing the potential existence of rater biases. In addition, format and training research may focus upon ways of enhancing both rater and ratee reactions to the appraisal system. A key feature of our model is the integration of national culture as a moderator of the relations between specific formats, training programs, and various outcomes. We consider both the national culture of raters and ratees, and focus specifically on comparisons between Western and East Asian cultures. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The use of visual search for knowledge gathering in image decision support

This paper presents a new method of knowledge gathering for decision support in image understanding based on information extracted from the dynamics of saccadic eye movements. The framework involves the construction of a generic image feature extraction library, from which the feature extractors that are most relevant to the visual assessment by domain experts are determined automatically through factor analysis. The dynamics of the visual search are analyzed by using the Markov model for providing training information to novices on how and where to look for image features. The validity of the framework has been evaluated in a clinical scenario whereby the pulmonary vascular distribution on Computed Tomography images was assessed by experienced radiologists as a potential indicator of heart failure. The performance of the system has been demonstrated by training four novices to follow the visual assessment behavior of two experienced observers. In all cases, the accuracy of the students improved from near random decision making (33%) to accuracies ranging from 50% to 68%.     

Design and initial operation of a 367-m2 rectangular ring laser

The design and operation of a proof-of-principle rectangular He-Ne ring laser resonator with a cavity perimeter of 77.0 m and an area of approximately 367 m2 are described. With unevacuated beam lines this device gave an Earth-induced Sagnac frequency of 1513 Hz, with a relative Allan deviation over 1000 s down to 3 parts per million. The Earth's rotation provided a bias that eliminated the lock-in susceptibility. The use of increased pressure in the plasma tube facilitated single-mode operation by increasing the homogeneous pressure-broadened linewidth.     

Use of accelerometers as an ergonomic assessment method for arm acceleration-a large-scale field trial

Ergonomists need easy-to-use, quantitative job evaluation methods to assess risk factors for upper extremity work-related musculoskeletal disorders in field-based epidemiology studies. One device that may provide an objective measure of exposure to arm acceleration is a wrist-worn accelerometer or activity monitor. A field trial was conducted to evaluate the performance of a single-axis accelerometer using an industrial population (n=158) known to have diverse upper limb motion characteristics. The second phase of the field trial involved an examination of the relationship between more traditional observation-based ergonomic exposure measures and the monitor output among a group of assembly-line production employees (n=48) performing work tasks with highly stereotypic upper limb motion patterns. As expected, the linear acceleration data obtained from the activity monitor showed statistically significant differences between three occupational groups known observationally to have different upper limb motion requirements. Among the assembly-line production employees who performed different short-cycle assembly work tasks, statistically significant differences were also observed. Several observation-based ergonomic exposure measures were found to explain differences in the acceleration measure among the production employees who performed different jobs: hand and arm motion speed, use of the hand as a hammer, and, negatively, resisting forearm rotation from the torque of a power tool. The activity monitors were found to be easy to use and non-intrusive, and to be able to distinguish arm acceleration among groups with diverse upper limb motion characteristics as well as between different assembly job tasks where arm monitors were performed repeatedly at a fixed rate.     

Second harmonic generation in ion-exchanged waveguides of semiconductor microcrystallite-doped glasses

Waveguides written in semiconductor microcrystalline-doped glasses using the ion-exchange method have been optically encoded for second harmonic generation of Nd:YAG radiation.<>     

Through the looking glass darkly? When self-doubts turn into relationship insecurities.

The authors argue that individuals regulate perceptions of their relationships in a self-protective way, finding virtue in their partners only when they feel confident that their partners also see virtues in them. In 4 experiments, the authors posed an acute threat to low and high self-esteem individuals' feelings of self-worth (e.g., guilt about a transgression, fears of being inconsiderate or intellectually inept). They then collected measures of confidence in the partner's positive regard and acceptance (i.e., reflected appraisals) and perceptions of the partner. The results revealed that low self-esteem individuals reacted to self-doubt with heightened doubts about their partners' regard, which then tarnished impressions of their partners. In contrast, high self-esteem individuals reacted to self-doubts by becoming more convinced of their partners' continued acceptance, using their relationships as a resource for self-affirmation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Posthyperventilation apnea associated with severe hypoxemia

We studied a 14-year-old girl who suffered fractures of her mandible and tegmen following a fall from a balance beam. Thirteen days after hospitalization, she developed severe, protracted, recurrent episodes of hyperventilation; subsequently, she suffered posthyperventilation apnea, which at times was prolonged and association with severe hypoxemia with an arterial oxygen pressure as low as 25 mm Hg. The patient was treated with added dead space and chlorpromazine hydrochloride (Thorazine). Postulated mechanisms for her disorder are discussed. The importance of close clinical and laboratory observation in similar cases is stressed.