• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.12-16
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• 2007

A dynamic model of proton exchange membrane fuel cell(PEMFC) system is designed to understand the performance of the PEMFC in residential power generator(RPG) over various balance of plant(BOP) options. In particular, since the performance of PEMFC system should be optimized for given operating ranges, it is necessary to design suitable BDP components which can support the operating ranges. The objective of this study is to develop a dynamic system model for the study of PEMFC performance over various BOP options. Therefore, a dynamic model is composed of a PEMFC stack model, a water management system model, a thermal management system model and a fuel/air supply model and the model is integrated under SIMULINK(R)environment. Basic simulation results will be presented.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.121-126
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• 2003

The objective of this research is to evaluate of seismic performance for reinforced concrete bridge piers with lap splices of longitudinal reinforcement steels using predicting of nonlinear hysteric behavior. For the purpose, enhanced analytical trilinear hystretic model has been proposed to simulate the force-displacement hysteretic curve of RC bridge piers under repeated reversal loads. The moment capacity and corresponding curvature in the plastic hinge have been determined, and the enhanced hysteretic behavior model by five different kinds of branches has been proposed for modeling the stiffness variation of RC section under cyclic loading. The strength and stiffness degradation index are introduced to compute the hysteretic curve for various confinement steel ratios, In addition, the modified curvature factor has been introduced to forecast of seismic performance of longitudinal steel lap spliced and retrofitted specimens. The results of this research will be useful to predict of seismic performance for longitudinal steel with lap spliced and its retrofitted specimens.

• Journal of Agricultural Extension & Community Development
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• v.15 no.4
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• pp.599-619
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• 2008

The study is to develop indicators for woman famers center using focus group meeting and AHP(Analytic Hierarchy Process), which is a method to derive relative weights for each evaluation indicators. The results of this study are as follows. We determined such as the three indicators that planning establishment(seven), promotion process of work(six), performance of work(nine). We analysed the weights of this indicators by AHP. The relative weights of performance of work was 0.5269, planning establishment 0.2554 and promotion process of work marked 0.2177. It was suggested that further research should be carried out to develop more objective assessment indicators.

• Journal of Korean Institute of Industrial Engineers
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• v.37 no.4
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• pp.408-414
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• 2011

The objective of this paper is to define local optimization algorithms (LOA) to solve Resource-Constrained Project Scheduling Problem (RCPSP) and analyze the performance of these algorithms. By representing solutions with activity list, three primitive LOAs, i.e. forward and backward improvement-based, exchange-based, and relocation-based LOAs are defined. Also, combined LOAs integrating two primitive LOAs are developed. From the experiments with standard test set J120 generated using ProGen, the FBI-based LOA demonstrates to be an efficient algorithm. Moreover, algorithms combined with FBI-based LOA and other LOA generate good solutions in general. Among the considered algorithms, the combined algorithm of FBI-based and exchangebased shows best performance in terms of solution quality and computation time.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1990.04a
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• pp.151-162
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• 1990

Occupational disease among typists such as Carpal Tunnel Syndrome(CTS) and tendonitis has increased along with rapid expansion of office automation. During typing, the posture can be defined as forearm pronation, ulnar abduction, wrist extension and finger flexion. The CTS results from awkward posture between forearm-wrist-hand and the keyboard arrangement. Therefore, ergonomic principles should be emphasized in keyboard design. The objective of the study is to improve keyboard design by analyzing anatomical posture of forearm and hand during typing. An experimental study was performed to investigate relationships between a keyboard and typing performance. Results showed that typing performance is dependent to angles and slopes of a keyboard. Statistical analysis indicated that the suggested ergonomic keyboard improved typing speed significantly(17%).

• Journal of Auto-vehicle Safety Association
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• v.8 no.4
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• pp.18-23
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• 2016

The objective of this study is to present the inspection standards of motorcycle brake system affecting motorcycle traffic accident. The inspection standards of motorcycle brake system recommended by CITA (International Motor Vehicle Inspection Committee) are studied. The brake performance for preventing the traffic accident is assessed by the brake efficiency. Considering the KMVSS (Korean Motor Vehicle Safety Standards) and the inspection standards of CITA, United Kingdom and Japan, the brake performance in the inspection standards of motorcycle is suggested. It is recommended that the efficiency of independent front and rear brakes are 40% and 27%, respectively. It is recommended that the efficiency of combined front and rear brakes is 50%.

• The Journal of Information Systems
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• v.12 no.2
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• pp.109-128
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• 2003

This study is intended to suggest an ideal direction of the information systems policy for the local small business firms. In an effort to accomplish this objective, this paper tried to identify the current states of the information systems and measure the level of the information systems of local small business firms based on the maturity stage and the development level. The study then explored the evidence how the maturity stage and the development level affect the business performance of the local small business firms. The research found out that the organizational factor such as the support of CEO and the financial factor such as IS investment took major roles to improve the business performance. Based on the research findings of this study, the paper suggested the desirable solution of the information system policy to deal with the problems the local small business firms need to overcome.

• Journal of information and communication convergence engineering
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• v.8 no.6
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• pp.618-622
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• 2010

The damages from DDoS attacks are increasing as DDoS attacks are taking various forms. This has resulted not only in decreased reliability of organizations and corporations but also in the threat of national security. Organizations and corporations are making significant efforts in developing a system through which they can appropriately correspond to DDoS attacks. However, the studies on objective index for evaluating the performance of DDoS correspondence are lacking. The majority of the existing studies have been on the information protection & management system on a large scale. Accordingly, the scope of this thesis will be limited to DDoS correspondence to propose correspondence index for quantitatively measuring and managing them. The statistical techniques such as SMART technique and factor analysis will be utilized accordingly.

• Speech Sciences
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• v.11 no.2
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• pp.51-67
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• 2004

The objective of this study was to investigate the effects in auditory performance and vocal development of Onomatopoeia and Mimetic Word Productive Training Program in prelingually deafened children with cochlear implantation. The effects were measured with Lip-profile (Listening progress profile: LiP), the number of utterances, vocal developmental level and phonetic inventory. Subjects were four children with cochlear implants who were able to detect speech sounds and environmental sounds. The Onomatopoeia and Mimetic word Productive Training Program was made up of 3 steps with 24 Onomatopoeia and Mimetic words. This study was pre and post design. The results of the study were as follows: First, after Onomatopoeia and Mimetic word Productive Training Program was treated, LiP score was significantly higher. Second, after this program was treated, the number of utterances and emergence of both canonical and postcanonical utterances were increased. Emergence of vowel and consonant Features were increased and diversified. In conclusion, Onomatopoeia and Mimetic Word Productive Training Program appeared to facilitate efficient auditory performance and vocal development.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.10
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• pp.939-944
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• 2004

The numerical methods including the performance analysis and the noise prediction of the centrifugal compressor impeller are coupled with the optimization design skill, which consists of response surface method, statistical approach, and genetic algorithm. The flow-field Inside of a centrifugal compressor is obtained numerically by solving Wavier-Stokes equations. and then the propagating noise is estimated from the distributed surface pressure by using Ffowcs Williams-Hawkings formulation. The quadratic response surface model with D-optimal 3-level factorial experimental design points is constructed to optimize the impeller geometry for the advanced centrifugal compressor. The statistical analysis shows that the quadratic model exhibits a reasonable fitting quality resulting in the impeller blade design with high performance and low far-field noise level. The influences of selected design variables, objective functions, and constraints on the impeller performance and the impeller noise are also examined as a result of the optimization process.