• 한국정밀공학회지
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• 제14권4호
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• pp.46-55
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• 1997

This paper presents the development of intelligent performance management of computer communication networks for larger-scale integrated systems and the demonstration of its efficacy using computer simula- tion. The innermost core of the performance management is based on fuzzy set theory. This fuzzy perfor- mance manager has learning ability by using principles of neuro-fuzzy model, neuralnetwork, genetic algo- rithm(GA). Two types of performance managers are described in this paper. One is the Neuro-Fuzzy Per- formance Manager(NFPM) of which learning ability is based on the conventional gradient method, and the other is GA-based Neuro-Fuzzy Performance Manager(GNFPM)with its learning ability based on a genetic algorithm. These performance managers have been evaluated via discrete event simulation of a computer network.

• 한국공작기계학회논문집
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• 제12권1호
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• pp.92-100
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• 2003

Using a quarter car model, an analytic method for performance estimation of a vehicle suspension system with respect to frequency response, RMS response and performance index is presented. From frequency response function, compromization of response performance to the whole frequency range is verified and from RMS response and performance index, sensitivity of ride md handling characteristics are examined. Using a full car model, sweet area(stable ride area) are determined and performance sensitivity is estimated according to the change of feedback gains. In order to esimate the output sensitivity, response we is displayed using a 3-dimensional contour plot. Design data n suggested for optimal design parameter esimation, which maximize the performance of the given suspension system.

• 한국유통학회지:유통연구
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• 제4권1호
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• pp.71-92
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• 1999

The basic purpose of this study is to investigate how the traits of the buyer-seller transaction-relationship relate to relationship performance, including relationship performance explicitly in the proposed model. The traits examined include relational norm, formalization, market uncertainty, and relationship investment. It is hypothesized that relational norm and formalization have positive impacts on relationships performance while market uncertainty has a minus impact. In addition, it is hypothesized that relational norm has a positive moderating impact on the effect of relationship investment--the investment and efforts for maintaining a relationship to relationship performance. A mail-survey to the manufacturers of machinery and equipment about their relationships with the parts suppliers was performed. Data provided a strong support for the hypotheses. As hypothesized, relationship performance and formalization generally had positive impacts on relationship performance and formalization generally had positive impacts on relationship performance while market uncertainty showed negative impacts. Also, there is a good evidence for the positive moderating effect of relational norm to the impact of relationship investment on relationship performance.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 추계학술대회 논문집
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• pp.1063-1066
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• 1996

On the prediction of driving performance, an acceleration performance is normally simulated in stall starting condition which is the engine status of full-throttle and high-speed. The lack of transient engine torque data makes the difficulty of predicting an acceleration performance on engine-idle start condition. A experimental equation of transient engine torque is derived from vehicle performance test data. It is applied to simulation the accleration performance prediction on idle starting condition.

• Asia pacific journal of information systems
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• 제13권1호
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• pp.119-140
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• 2003

The business value of IT has been the focus of the academic and business field in recent years, along with the massive IT investment. Unfortunately, those studies have not been able to demonstrate strong linkages between the IT investment and performance. The impact of IT investment on performance is an important research topic that needs to consider the role of key contextual factors and intermediate factors. This study develops an integrated model for IT investment, with the mediating effects of production/coordination performance towards firm performance. In addition, the model is moderated by some factors like ISP(Information Systems Planning), Business Planning alignment, top management support, IT education and training, and process innovation. The empirical result, based on the moderating regression analysis, indicates that the relationship between IT Investment and production/coordination performance is significantly positive depending on moderating factors. However, production/coordination performance is partially related to firm performance.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2017년도 추계 학술논문 발표대회
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• pp.32-33
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• 2017

In order to improve the flow performance of high performance concrete, use of high performance water reducing agent and low viscosity type water reducing agent is a study of suitable range of use due to side effects. in this study, we aimed at reducing viscosity and yield value using high performance water reducing agent and low viscosity type water reducing agent, and this was evaluated using a rheometer. as a result of analysis of viscosity and yield value, it was found that the high performance water reducing agent has higher reduction effect than the low viscosity type water reducing agent. however, the larger the viscosity lowering effect is, the lower the usable range is, compared to general high performance water reducing agents, and it was found that sufficient consideration for this judgment of appropriate quantity is necessary.

• ETRI Journal
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• 제44권1호
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• pp.117-124
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• 2022

In this paper, the performance of precoding-aided differential spatial modulation (PDSM) systems with optimal transmit antenna subset (TAS) selection is examined analytically. The average bit error rate (ABER) performance of the optimal TAS selection-based PDSM systems using a zero-forcing (ZF) precoder is evaluated using theoretical upper bound and Monte Carlo simulations. Simulation results validate the analysis and demonstrate a performance penalty < 2.6 dB compared with precoding-aided spatial modulation (PSM) with optimal TAS selection. The performance analysis reveals a transmit diversity gain of (N_T-N_R+1) for the ZF-based PDSM (ZF-PDSM) systems that employ TAS selection with N_T transmit antennas, N_S selected transmit antennas, and N_R receive antennas. It is also shown that reducing the number of activated transmit antennas via optimal TAS selection in the ZF-PDSM systems degrades ABER performance. In addition, the impacts of channel estimation errors on the performance of the ZF-PDSM system with TAS selection are evaluated, and the performance of this system is compared with that of ZF-based PSM with TAS selection.

• Nuclear Engineering and Technology
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• 제37권5호
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• pp.491-502
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• 2005

Reliable human performance is a prerequisite in securing the safety of complicated process systems such as nuclear power plants. However, the amount of available knowledge that can explain why operators deviate from an expected performance level is so small because of the infrequency of real accidents. Therefore, in this study, a database that contains a set of useful information extracted from simulated emergencies was developed in order to provide important clues for understanding the change of operators' performance under stressful conditions (i.e., real accidents). The database was developed under Microsoft Windows TM environment using Microsoft Access $97^{TM}$ and Microsoft Visual Basic $6.0^{TM}$. In the database, operators' performance data obtained from the analysis of over 100 audio-visual records for simulated emergencies were stored using twenty kinds of distinctive data fields. A total of ten kinds of operators' performance data are available from the developed database. Although it is still difficult to predict operators' performance under stressful conditions based on the results of simulated emergencies, simulation studies remain the most feasible way to scrutinize performance. Accordingly, it is expected that the performance data of this study will provide a concrete foundation for understanding the change of operators' performance in emergency situations.

• 한국IT서비스학회지
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• 제16권4호
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• pp.65-75
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• 2017

The purpose of this study is to investigate how software policy shows the moderating effects between organizational capability maturity and organizational performance. The software policy includes the proportions of development personnel and development budget that can affect organizational performance. It is important to empirically identify whether the ratios of budget and personnel, which are some of the main policy indexes of the organization can promote the causal relationship between organizational maturity and organizational performance. These personnel and budget may be assumed to affect the causal relationship between organizational capability maturity and organizational performance. The results of this study shows that the moderating effects of software policy are partially proved. The two policy indexes, personnel ratio and budget ratio, showed a moderating effect between process implementation and organizational performance, but did not show any moderating effect between quantitative management and organizational performance. This is because the companies participating in the survey are still in the early stages of quantitative process management and quantitative management does not show the differentiated results among the participating organizations. The significance of this study is as follows. In the academic aspect, the causal relationship between organizational maturity and organizational performance was examined empirically, and it was analyzed whether the two adopted policy indicators have a moderating effect between organizational maturity and organizational performance. On the practical side, the analysis suggested that the ratios of budget and personnel emphasized by the government or organization played a role of facilitating the organizational maturity and organizational performance.

• 한국정밀공학회지
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• 제11권4호
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• pp.138-147
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• 1994

Performance management of computer networks is intended to improve a given network performance in order for more efficient information exchange between subsystems of an integrated large-scale system. Improtance of performance management is growing as many function of the large- scale system depend on the quality of communication services provided by the network. The role of performance management is to manipulate the adjustable protocol parameters on line so that the network can adapt itself to a dynamic environment. This can be divided into two subtasks : performance evaluation to find how changes in protocol parameters affect the network performance and decision making to detemine the magnitude and direction of parameter adjustment. This paper is the second part of the two papers focusing on conceptual design, development, and evaluation of performance management for token bus networks. This paper specifically deals with the task of decision making which utilizes the principles of stochastic optimization and learning automata. The developed algorithm can adjuxt four timer settings of a token bus protocol based on the result of performance evaluation. The overall performance management has been evaluated for its efficacy on a network testbed.