Genetic algorithm based neural classifiers for factor subset extraction

A clear understanding of risk factors is important to develop appropriate prevention and control strategies for infection caused by such pathogens as Salmonella Typhimurium. In this study, there are 91 risk factors that nonlinearly contribute to the Salmonella Typhimurium infection and many of them are not of significance. It is very important to automatically extract a factor subset with those important risk factors. This paper proposes a genetic algorithm for factor subset extraction in conjunction with neural and statistical classifiers to classify case and control status in Salmonella Typhimurium infection. The results show that the proposed approach is able to find an appropriate factor subset and the proposed neural classifiers outperform the traditional statistical classifiers. A statistical analysis is conducted by varying the parameters in the genetic algorithm based neural classifier to minimise the prediction error and determine the optimal system configuration.     

Characterizing communication networks in a web-based classroom: Cognitive styles and linguistic behavior of self-organizing groups in online discussions

In this study, we explore the cognitive style profiles and linguistic patterns of self-organizing groups within a web-based graduate education course to determine how cognitive preferences and individual behaviors influence the patterns of information exchange and the formation of communication hierarchies in an online classroom. Network analysis was performed on communication data collected from 1131 student messages posted in 19 asynchronous online discussion forums to determine centrality, clique membership, and core-periphery structure in the communication networks. The social network data were examined in relation to the students' cognitive style profiles, which were assessed using the Kirton Adaption-Innovation Inventory (KAI) (32 and 33). The cognitive style composition of small cliques (dyadic and triadic) was found to be highly heterogeneous, often with large cognitive gaps between clique members, which suggests that web-based environments may mask cognitive style differences that have been shown to create conflict in face-to-face interactions. In addition, the cognitive style mean of the students in the core of the network was found to be significantly more adaptive than that of the periphery group. To further characterize the nature of the communicative interactions, automated linguistic analysis was used to analyze the students' writing samples. Interestingly, students in the core of the social network demonstrated a significantly higher usage of several language features associated with individuals who actively promote enhanced group performance and cohesion. For our sample, the linguistic behaviors of students in the core of the social network, coupled with their more adaptive cognitive style preferences, suggest that these students may inherently place greater value on fostering group cohesion than those in the periphery.     

Pulsed-Laser Deposition of Barium Titanate Thin Films

Barium titanate (BaTiO₃) thin films have been deposited on single-crystal magnesia (MgO) substrates by pulsed-laser ablation. Temperature dependence of capacitance measurements show a peak of 110°C, indicative that a ferroelectric phase transition has occurred at this temperature. This value is lower than that determined for single-crystal BaTiO₃, but consistent with that found for BaTiO₃ thin films produced by other methods. It has been demonstrated that the microstructure of the films can be varied by changes in the deposition parameters. Optimizing these variations permits the formation of thin films with controlled microstructures and properties.     

Optimized Synthesis of Salicylate-based Poly( anhydride-esters)

Summary The synthesis of a salicylate-based poly(anhydride-ester) was optimized to improve the overall efficiency and quality of the polymer. First, a new approach for the preparation of the polymer precursor minimizes the overall number of synthetic steps and increases the overall yield. Second, the melt-polymerization apparatus was modified to include dynamic mixing, which yields polymer with increased molecular weights on both the milligram and gram scale. Received: 2 October 2002/Accepted: 6 January 2003 Correspondence to Kathryn E. Uhrich     

Using team cognitive work analysis to reveal healthcare team interactions in a birthing unit

Cognitive work analysis (CWA) as an analytical approach for examining complex sociotechnical systems has shown success in modelling the work of single operators. The CWA approach incorporates social and team interactions, but a more explicit analysis of team aspects can reveal more information for systems design. In this paper, Team CWA is explored to understand teamwork within a birthing unit at a hospital. Team CWA models are derived from theories and models of teamwork and leverage the existing CWA approaches to analyse team interactions. Team CWA is explained and contrasted with prior approaches to CWA. Team CWA does not replace CWA, but supplements traditional CWA to more easily reveal team information. As a result, Team CWA may be a useful approach to enhance CWA in complex environments where effective teamwork is required.

Practitioner Summary: This paper looks at ways of analysing cognitive work in healthcare teams. Team Cognitive Work Analysis, when used to supplement traditional Cognitive Work Analysis, revealed more team information than traditional Cognitive Work Analysis. Team Cognitive Work Analysis should be considered when studying teams.     

Application of a reliability model generator to a pressure tank system

A number of mathematical modelling techniques exist which are used to measure the performance of a given system, by assessing each individual component within the system. This can be used to determine the failure frequency or probability of the system. Software is available to undertake the task of analysing these mathematical models after an individual or group of individuals manually create the models. The process of generating these models is time consuming and reduces the impact of the model on the system design. One way to improve this would be to generate the model automatically. In this work, the procedure to automatically construct a model, based on Petri nets, for systems undergoing a phased-mission is applied to a pressure tank system, undertaking a four phase mission.     

A Study of Gimlet Use in Reference Transactions

The focus of this research study is a web-based reference tracking tool called Gimlet. Surveys were sent to State University of New York at Oswego (SUNY Oswego) librarians and to librarians and staff in the United States and abroad. Results indicated that SUNY Oswego librarians find Gimlet a useful and convenient tool that helps them feel productive while generating informative statistics. Respondents outside SUNY Oswego found Gimlet easy to administer and customize, but required improved functionality to generate reports. The reports are valuable to librarians and administrators for evaluating programs. Although Gimlet is user friendly, a library's needs vary according to customizable options and in the generating of reports.     

Detecting memory leaks in managed languages with Cork

A memory leak in a managed language occurs when the program inadvertently maintains references to objects that it no longer needs. Memory leaks cause systematic heap growth that degrade performance and can result in program crashes after perhaps days or weeks of execution. Prior approaches for detecting memory leaks rely on heap differencing or detailed object statistics which store state proportional to the number of objects in the heap. These overheads preclude their use on the same processor for deployed long‐running applications. This paper introduces Cork as a tool that accurately identifies heap growth caused by leaks. It is space efficient (adding less than 1% to the heap) and time efficient (adding 2.3% on average to total execution time). We implement this approach of examining and summarizing the class of live objects during garbage collection in a class points‐from graph (CPFG). Each node in the CPFG represents a class and edges between nodes represent references between objects of the specific classes. Cork annotates nodes and edges with the corresponding volume of live objects. Cork identifies growing data structures across multiple collections and computes a class slice to identify leaks for the user. We experiment with two functions for identifying growth and show that Cork is accurate: it identifies systematic heap growth with no false positives in 4 of 15 benchmarks we tested. Cork's slice report enabled us to quickly identify and eliminate growing data structures in large and unfamiliar programs, something their developers had not previously done. Copyright © 2009 John Wiley & Sons, Ltd.     

Psychometric adequacy and comparability of the short and full forms of the Personality Assessment Inventory.

The 160-item short form of the Personality Assessment Inventory (PAI) was developed for situations in which respondents complete only the 1st half of the test. The present study evaluates the adequacy and comparability of the full and short forms of the PAI in terms of a wide range of psychometric characteristics. In all, 421 participants completed the full form as part of a neuropsychological evaluation. Results indicated slightly lower internal consistency reliability of the short compared with the full form. Group-level agreement of short and full form scales ranged from adequate to excellent. However, within-subject agreement was somewhat more variable. Low levels of within-subject agreement were strongly associated with elevated validity scale scores. The factor structures of the full and short forms showed high congruence for a 3-factor solution. These findings suggest that many scales of the short form have adequate comparability with their respective full form scales. However, low levels of reliability across less impaired ranges of the latent trait, diminished content coverage, and altered validity detection may limit the utility of some of the short form scales. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A Randomized Trial Comparing the Effects of Self-Help Materials and Proactive Telephone Counseling on Teen Smoking Cessation.

We conducted a 2-arm randomized trial to test the efficacy of self-help materials with or without proactive telephone counseling to increase cessation among teen smokers. Teen smokers (N = 402) recruited from 11 shopping malls and 1 amusement park in the southeastern United States were randomized to 1 of 2 groups: written self-help material plus video; or written self-help material, video, and telephone counseling. Cessation rates based on 7-day point-prevalent abstinence for the self-help and counseling arms were 11% and 16%, respectively (p = .25), at 4 months postbaseline and 19% and 21%, respectively (p = .80), at 8 months postbaseline. Sustained abstinence, reflecting 7-day abstinence at both time points, in the self-help and counseling arms was 7% and 9% (p = .59). Results suggest that minimal self-help cessation approaches that target youth have comparable success to that shown among adult smokers. However, refinements in telephone-counseling approaches may be needed to achieve the success observed in adult populations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)