71,224 research outputs found

    Parallel eigenanalysis of finite element models in a completely connected architecture

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    A parallel algorithm is presented for the solution of the generalized eigenproblem in linear elastic finite element analysis, (K)(phi) = (M)(phi)(omega), where (K) and (M) are of order N, and (omega) is order of q. The concurrent solution of the eigenproblem is based on the multifrontal/modified subspace method and is achieved in a completely connected parallel architecture in which each processor is allowed to communicate with all other processors. The algorithm was successfully implemented on a tightly coupled multiple-instruction multiple-data parallel processing machine, Cray X-MP. A finite element model is divided into m domains each of which is assumed to process n elements. Each domain is then assigned to a processor or to a logical processor (task) if the number of domains exceeds the number of physical processors. The macrotasking library routines are used in mapping each domain to a user task. Computational speed-up and efficiency are used to determine the effectiveness of the algorithm. The effect of the number of domains, the number of degrees-of-freedom located along the global fronts and the dimension of the subspace on the performance of the algorithm are investigated. A parallel finite element dynamic analysis program, p-feda, is documented and the performance of its subroutines in parallel environment is analyzed

    Hot-bench simulation of the active flexible wing wind-tunnel model

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    Two simulations, one batch and one real-time, of an aeroelastically-scaled wind-tunnel model were developed. The wind-tunnel model was a full-span, free-to-roll model of an advanced fighter concept. The batch simulation was used to generate and verify the real-time simulation and to test candidate control laws prior to implementation. The real-time simulation supported hot-bench testing of a digital controller, which was developed to actively control the elastic deformation of the wind-tunnel model. Time scaling was required for hot-bench testing. The wind-tunnel model, the mathematical models for the simulations, the techniques employed to reduce the hot-bench time-scale factors, and the verification procedures are described

    The Relationship Between Employee Perceptions of the Employment Game and Their Perceptions of Cooperative Knowledge Behavior in High Tech Firms

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    The relationship between knowledge sharing and organizational performance for high technology start-up companies is not well understood. Using game theory and the concept of competitive advantage through human resource management, I examine employee perceptions of the employment game relating to cooperative knowledge behavior and firm performance as an entry point into researching organizational knowledge utilization. I draw upon classical game theory to develop four measures of perceptions critical to game playing and apply these to organizational situations via a survey instrument. I propose that perceptions of the employment game held by organization members are determinants of cooperative knowledge sharing and subsequently firm performance. I analyze survey data gathered from high-tech workers using both regression and path analysis techniques. The results from this study offer new insights into methods for measuring both the connections between knowledge work and firm performance and the perceptions critical for fostering collaborative knowledge work in high tech firms. Results of the study show a significant relationship between the game theory construct of reciprocity, knowledge building behavior and firm performance. The mediation model was weakly supported but shows potential usefulness for further research in the field of strategic human resource management

    Feasibility study of an Integrated Program for Aerospace vehicle Design (IPAD). Volume 1B: Concise review

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    Reports on the design process, support of the design process, IPAD System design catalog of IPAD technical program elements, IPAD System development and operation, and IPAD benefits and impact are concisely reviewed. The approach used to define the design is described. Major activities performed during the product development cycle are identified. The computer system requirements necessary to support the design process are given as computational requirements of the host system, technical program elements and system features. The IPAD computer system design is presented as concepts, a functional description and an organizational diagram of its major components. The cost and schedules and a three phase plan for IPAD implementation are presented. The benefits and impact of IPAD technology are discussed

    HOW TO INCREASE EMPLOYEE’S DISCIPLINARY IN FACULTY MEDICINE OF DIPONEGORO UNIVERSITY

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    Human Capital plays an important role in organization. It is the heart of the organization strategy. Many factors embeded in it. Public Service employees as government human capital instead of the contract employees. The quality of the Public Service Employee has recently become a major issue. It is widely known that Public Service employee is lacking of disciplin. The issue discuss most in Public service employee’s disciplinary is absentheeism. This study presents factors that influence the Public Service employee’s disciplinary in Faculty of Medicine of Diponegoro University. This research purposes will support the decision – making process to increase the Faculty of Medicine of Diponegoro University employee’s disciplinary, this study proposing some models analyzed by SEM. The study population is administration staffs in Faculty of Medicine of Diponegoro University for both Public Service employees and contract employees. The respondents are 120 employees whose given some questionaires related to the study. The result of the data analysis shows that the human capital is influenced by knowledge sharing, empowerment and workplace environment. Whilst human capital influences employee’s disciplinary positively

    Productivity, Growth, and Internationalisation: The Case of German and British High Techs

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    International engagement is often expected to improve firm performance. Especially for small technology-oriented firms, export activities may be important, being regarded as one way to amortise these firms? high product research and development costs. This paper examines the relationship between international business activities and firm performance using a sample of about 200 young high-tech firms in Germany and the UK that were contacted by two surveys in 1997 and 2003. I find out that the performance enhancing effects of internationalisation that were still observed in 1997 are in fact restricted to an early stage of the firms? life cycles and disappear when technology-oriented firms become mature. The results are in line with many other studies: Firms exhibiting superior performance are or will become exporters. --High technology industries,internationalisation,firm growth,productivity,switching

    Optimizing compilation with preservation of structural code coverage metrics to support software testing

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    Code-coverage-based testing is a widely-used testing strategy with the aim of providing a meaningful decision criterion for the adequacy of a test suite. Code-coverage-based testing is also mandated for the development of safety-critical applications; for example, the DO178b document requires the application of the modified condition/decision coverage. One critical issue of code-coverage testing is that structural code coverage criteria are typically applied to source code whereas the generated machine code may result in a different code structure because of code optimizations performed by a compiler. In this work, we present the automatic calculation of coverage profiles describing which structural code-coverage criteria are preserved by which code optimization, independently of the concrete test suite. These coverage profiles allow to easily extend compilers with the feature of preserving any given code-coverage criteria by enabling only those code optimizations that preserve it. Furthermore, we describe the integration of these coverage profile into the compiler GCC. With these coverage profiles, we answer the question of how much code optimization is possible without compromising the error-detection likelihood of a given test suite. Experimental results conclude that the performance cost to achieve preservation of structural code coverage in GCC is rather low.Peer reviewedSubmitted Versio

    Apollo experience report: Guidance and control systems - Digital autopilot design development

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    The development of the Apollo digital autopilots (the primary attitude control systems that were used for all phases of the lunar landing mission) is summarized. This report includes design requirements, design constraints, and design philosophy. The development-process functions and the essential information flow paths are identified. Specific problem areas that existed during the development are included. A discussion is also presented on the benefits inherent in mechanizing attitude-controller logic and dynamic compensation in a digital computer

    The role of organizational and individual variables in aircraft maintenance performance

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    Aviation maintenance has been identified by the FAA as an area where better efficiency is needed to cope with ever increasing workloads. However, aviation maintenance has also been identified as one of the major causes of accidents. Consequently, if further efficiencies are to be achieved, they cannot come at the cost of reduced safety margins. The present study employed a safety climate approach to assist in the development of a model that can help to explain morale, psychological health, turnover intentions, and error in the aviation maintenance environment. An instrument called the Maintenance Environment Survey was developed and administered to 240 personnel responsible for maintenance of a large military helicopter fleet. Data collected through the survey were used to develop a structural model that predicted 45 per cent of the variance in psychological health, 67 per cent of the variance in morale, 27 per cent of the variance in turnover intentions, and 44 per cent of the variance in self-reported maintenance errors. The model shows the pathways through which organizational level and individual level variables can influence work outcomes and leads to suggestions for interventions that can help to improve maintenance efficiency
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