• Journal of the Korea Institute of Information and Communication Engineering
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• v.2 no.4
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• pp.553-558
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• 1998

We present in this paper the ture union bound of the performance of chip level detection for coded DS/CDMA system operating in Rician fading channels such as LEO satellite mobile radio where the maximum doppler frequency is very high. The main objective of this paper is to calculate the exact doe union bound of BER performance of different performance of different quadrature detectors and to find a optimum spreading factor as a function of fade rate. The rationale of using multiple chip detection is to reduce the effective fade rate or variation. We considered chip level differential detection, chip level maximum likelihood sequence estimation, noncoherent detection and coherent detection with perfect channel state information as a reference.

• Journal of Korean Institute of Industrial Engineers
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• v.21 no.1
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• pp.17-32
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• 1995

The objective of this study is to develop a general design and performance evaluation model for the system designers in the initial design phase of the integrated automatic manufacturing system based on the RAM(Reliability, Availability and Maintainability) and life cycle cost(LCC). The methodology proposed in this research includes the following two stages. First, a deterministic approach to the solution of optimal work station arrangement for the initial system configuration is considered under the assumption that the system availability is one(no failure and maintenance), and then a stochastic simulation model based on RAM and LCC is developed. Using the results of these two stage simulation, a system performance index(SPI) was developed for the performance evaluation of the proposed system. Also a computer program is developed.

• School Mathematics
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• v.1 no.1
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• pp.187-216
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• 1999

The purpose of this study is to develop mathematics performance assessment items for the 8th graders and to analyze their performance ability. First, five-themes were selected : 'Calculator', 'Cut and Paste', 'Rule finding', 'Place Assignment', 'My thinking'. Then, the assistance of Mathematics education specialists and Teachers, 10 P. A. items consisting of two subtasks and their evaluation rubric were developed. Then, items were revised by the results of pilot test. And, final version of items were administrated to the 8th graders of three regions(Seoul, Chongiu, Chungp$\acute{y}$ong). Through analyzing the performance ability of the subjects assessment items, the following conclusion were obtained: They were very insufficient in the ability to find some patterns in the given problem situation and to describe logically the patterns in terms of mathematical terminology. It is believed because they were familiar with the objective test to take one or short answer.

• Journal of the Korean Operations Research and Management Science Society
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• v.34 no.1
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• pp.101-121
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• 2009

The research literature presents that Total Quality Management (TQM) has been successfully embraced by firms for strategic and operational management in the last decades. However few studios analyze the role of TQM practices in the R&D environment. The objective of this study is to evaluate TQM practices implemented in manufacturing-based R&D organizations with respect to R&D performance. Our research model is primarily based on Malcolm Baldrige Criteria for Performance Excellence framework, including three moderating variables (industry type, organization size, quality management system certification), to propose hypotheses on the relationships between leadership practice, management practice and R&D performance. Results of canonical correlation analysis using data from 130 R&D organizations show that in aggregate leadership practice is positively related to management practice which is, in turn, positively related to R&D performance. These relationships are, however, affected by the moderating variables. Our results imply that TQM practices can be strategically adopted in the R&D organization.

• Structural Engineering and Mechanics
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• v.37 no.5
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• pp.543-560
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• 2011

In structural engineering there are randomness inherently exist on determination of the loads, strength, geometry, and so on, and the manufacturing of the structural members, workmanship etc. Thus, objective and constraint functions of the optimization problem are functions that depend on those randomly natured components. The constraints being the function of the random variables are evaluated by using reliability index or performance measure approaches in the optimization process. In this study, the minimum weight of a space truss is obtained under the uncertainties on the load, material and cross-section areas with harmony search using reliability index and performance measure approaches. Consequently, optimization algorithm produces the same result when both the approaches converge. Performance measure approach, however, is more efficient compare to reliability index approach in terms of the convergence rate and iterations needed.

• Proceedings of the KSRS Conference
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• v.2
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• pp.615-618
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• 2006

By introducing Web Services, distributed GIS services from different vendors can be dynamically integrated into a GIS application using the interoperable standard SOAP protocol. However, it is debatable whether SOAP can really meet the performance requirements of GIS. This paper presents an experimental evaluation of the performance of different SOAP variants: standard SOAP, SwA/MIME, and SOAP/MTOM. The objective of this paper is to demonstrate that SOAP performance in communicating large volumes of GIS data could be effectively improved by recent standards. Moreover, SOAP/MTOM is identified to be the fastest and the most efficient messaging protocol.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.281-286
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• 2005

The main objective of the research work presented in this article is to present a systematic approach for designing a multilayer feed-forward artificial neural network based self-tuning power system stabilizer (ST-ANNPSS). In order to suggest an approach for selecting the number of neurons in the hidden layer, the dynamic performance of the system with ST-ANNPSS is studied and hence compared with that of conventional PSS. Finally the effect of variation of loading condition and equivalent reactance, Xe is investigated on dynamic performance of the system with ST-ANNPSS. Investigations reveal that ANN with one hidden layer comprising nine neurons is adequate and sufficient for ST-ANNPSS. Studies show that the dynamic performance of STANNPSS is quite superior to that of conventional PSS for the loading condition different from the nominal. Also it is revealed that the performance of ST-ANNPSS is quite robust to a wide variation in loading condition.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2001.04a
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• pp.361-367
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• 2001

This research aims at evaluating the seismic performance of the R/C bridge piers, which were seismically designed in accordance with the seismic provision of limited ductile behavior of Eurocode 8. Pseudo dynamic test for six(6) circular RC bridge piers has been carried out so at to investigate their seismic performance subjected to experted artificial earthquake motions. The objective of this experimental study is to investigate the hysteretic behavior of reinforced concrete bridge piers. Important test parameters are confinement steel ratio, input ground motion, etc. The seismic behavior of circular concrete piers under artificial ground motions has been evaluated through displacement ductility, energy analysis, capacity spectrum. It can be concluded that RC bridge piers designed in the seismic code of limited ductile behavior of Eurocode 8 have been determined to show good seismic performance even under expected artificial earthquakes in moderate seismicity region.

• The KSFM Journal of Fluid Machinery
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• v.6 no.2 s.19
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• pp.41-46
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• 2003

The hydraulic design optimization and performance analysis of mixed-flow pumps for waterjet marine vehicle propulsion has been carried out using mean streamline analysis and three-dimensional computational fluid dynamics (CFD) code. In the present study, the conceptual design optimization has been formulated with a non-linear objective function to minimize the fluid dynamic losses, and then the commercial CFD code was incorporated to allow for detailed flow dynamic phenomena in the pump system. Newly designed mixed-flow model pump has been tested in the laboratory. Predicted performance curves by the CFD code agree very well with experimental data for a newly designed mixed-flow pump over the normal operating conditions. The design and prediction method presented herein can be used efficiently as a unified hydraulic design process of mired-flow pumps for waterjet marine vehicle propulsion.

• Journal of Information Technology Applications and Management
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• v.23 no.2
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• pp.113-141
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• 2016

This study identifies and validates the factors that affect sales performance of salespersons in the business software industry. In the study, in order to measure the dependent variable (performance of the salesperson) more comprehensively, multiple items are utilized and both outcome and behavior indicators are used. Independent variables are identified based on the classification of Verbeke et al. [(2011] including sales related knowledge, degree of adaptiveness, role ambiguity, and work engagement. Results of the hypotheses testing show that 'sales related knowledge' and 'work engagement' are statistically significant factors, but 'degree of adaptiveness' and 'role ambiguity' are not. This study has a few limitations and future research direction to overcome the limitation is suggested : use of both perceptions of the salesperson and objective measures in measuring the related variables; study including cognitive ability; analyses of the factors across various types of software companies; and analyses of the factors on the team level.