• Journal of Mechanical Science and Technology
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• 제14권11호
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• pp.1296-1304
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• 2000

A program of steady-state and transient performance analysis for a 200kW-class small turboshaft engine with free power turbine was developed. An existing turbojet engine was used for the gas generator of the developed turboshaft engine, which was modified to satisfy performance requirements of this turboshaft engine. To verify the accuracy of steady-state performance program for this engine: the program was applied to the gas turbine test unit of the same type, and the analysis results were compared with experimental results. The developed transient performance analysis program using the CMF (Constant Mass Flow) method was utilized to analyze the cases of step increase and ramp increase of the fuel.

• Proceedings of the Korea Society for Simulation Conference
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• 한국시뮬레이션학회 2005년도 춘계학술대회 논문집
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• pp.50-55
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• 2005

웹 서비스와 웹 프로세스(Web Processes)는 다양한 시스템 상에서 이종의 소프트웨어 컴포넌트들을 효과적으로 통합할 수 있는 기술이다. 웹 서비스의 활용이 증대함에 따라 성능(performance), 비용(cost) 등 005(Quality of Service)는 서비스 제공자들 간의 차별화를 위한 요건으로 그 중요성이 증가하고 있다. 본 논문에서는 웹 서비스 성능 분석 도구인 sPAC(Web Service Performance Analysis Center)을 소개하여, 웹 서비스 조합시 성능의 만족 여부를 미리 고려할 수 있음을 보인다. sPAC은 1) 그래픽 기반 웹 프로세스 구성 환경을 제공, 2) 경부하(light load) 조건에서의 성능 테스트를 위해 웹 서비스를 호출, 3) 웹 프로세스에 대한 시뮬레이션 모델을 자동 생성 하여, 과부하(heavy load) 조건에서 시뮬레이션 기반의 성능 분석 수행, 4) 웹 서비스의 성능 분석 결과와 평가 데이터의 보고서 생성을 제공한다.

• Journal of Information Technology Services
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• 제6권1호
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• pp.65-81
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• 2007

Recently, the affiliates of the Ministry of Information and Communication have been conducting a performance evaluation study on IT policy projects, based on the performance evaluation model of the U.S. Office of Management and Budgets, with regard to investment in computerization. The performance evaluation model for the policy project could provide the objective information required for the planning, development, and operation of the policy project. However, the performance of the most policy project is likely to be evaluated using the subjective evaluation criteria of evaluators. Therefore, this case study evaluates the relative efficiency using DEA (Data Envelopment Analysis) in order to improve the performance evaluation method of the digital pioneer' project implemented by the Korea IT Industry Promotion Agency. The improvement value of inefficient Decision Making Units (DMUs) was measured by a static efficiency analysis. The measured value will suggest a objective viewpoint of the performance between DMUs to evaluators. In doing so, it will show an appropriate direction for the policy project to be evaluated successfully.

• International conference on construction engineering and project management
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.738-746
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• 2009

The purpose of this study is to develop the web-based system for work performance analysis(WPAS). The need of work performance analysis system has already been suggested in many previous researches on the computerization of the performance measurement in the construction site by using the indicators such as time, cost and quality. However, they had focused on measuring or analyzing the result when the project would be over. The WPAS suggests three indicators - work reliability, work effectiveness and work efficiency - to manage the performance of the construction site. It can help the manager more easily recognize the status of on-going work in the construction site by measuring and analyzing the work reliability rate, the work effectiveness and work efficiency every day. This research includes the procedures for WPAS measurement process, database structure of WPAS which was analyzed by the IDEF0 and the data flow diagram. Finally, this research introduces the result of WAPS's case studies and validation in the Korean construction site.

• International conference on construction engineering and project management
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.616-617
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• 2015

Demand is increasing for large, high-rise, and complex buildings, which is leading to advances in the development of high-performance structural systems. In this context, precast concrete (PC) technology has received a large amount of attention owing to its benefits in terms of schedule reduction, high quality, and easy installation. In addition, advanced methodologies that improve the PC performance by the addition of various materials have recently been reported. Research on analyzing the effects of such high-performance PC on the construction process and productivity is very limited. This makes it difficult for decision-makers to apply PC to particular projects. Thus, the aim of this research was to analyze the work productivity of the high-performance PC slab installation process by using a construction simulation tool to resolve critical issues. In this study, a real construction project that adopted PC slab installation work was analyzed, and a sensitivity analysis was performed to confirm the reliability of the analysis results.

• Journal of Information Technology Applications and Management
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• 제29권6호
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• pp.63-80
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• 2022

In this paper, we study structural changes and performance gains in condition-based maintenance process redesign when mobile IoT technology is embedded into urban railway rolling stock. We first develop condition-based maintenance To-Be process model in accordance with the IoT deployment scheme. Secondly, we draw upon theoretical framework of redesign process analysis to develop performance evaluation method suitable to predictive maintenance shift from As-Is ordinary maintenance practice. Subsequently, To-Be process performance evaluations are conducted adopting both the quantitative and qualitative method for time, cost, and dependability dimensions. The results ascertain the considerable benefits captured through detection abnormality prior to actual rolling stock failure occurrence, and details of performance improvements and enhancement of standardization level is revealed. The procedures and results presented in this paper offers useful insights in the fields of IoT economic analysis, condition based maintenance, and business process redesign.

• Culinary science and hospitality research
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• 제22권6호
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• pp.52-60
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• 2016

This study attempts to measure the financial performance of the food distribution company. In order to achieve the goal, this study have measured the ratios of ROE, ROA applying the DuPont analysis, which have been demonstrated with tables to show the change periodically. DuPont analysis is based on analysis of Return on Equity (ROE) & Return on Investment (ROI). The return on equity disaggregate performance into three components: Net Profit Margin, Total Asset Turnover, and the Equity Multiplier. The return on investment consists of Assets Turnover (Operating Income${\times}$Total Assets) and Profit Margin (EBIT${\times}$Operating Income). From the study it if found that Hyundae Green Food's Financial performance is high followed by Foodmerce and then Dongwon home food and Lotte Food. The four companies are significant at their level. In conclusion, ROE & ROI is the most comprehensive measure of profitability of a firm. It considers the operating and investing decisions can be made as well as the financing and their leverage-related decisions.

• Proceedings of the KSME Conference
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• 대한기계학회 2001년도 춘계학술대회논문집E
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• pp.649-654
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• 2001

This paper describes aerodynamic preliminary design performance prediction and flow analysis for centrifugal compressor of the marine middle engine turbocharger. The performance characteristics of turbocharger compressor are investigated at various operating conditions using mass flow rate and revolution speed, and computational flow analysis for impeller and diffuser at design point are performed. Preliminary design results correspond to actual compressor geometric values comparatively by applying modified slip factor. Performance prediction and flow analysis results show good agreement with experiments. Therefore, this will provide the performance prediction in preliminary design, and help to increase the design capability for optimized impeller.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.478-479
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• 2009

The HEMU-400X(High-speed Electric Multiple Unit 400km/h eXperimental) project starts in 2007. It is required to analysis and simulate the train performance throughout the project life cycle for a successful completion of the project. This paper is devoted to the development of a train performance analysis model for the high-speed electric multiple unit 400km/h experimental. The model consist of running resistance model, train model, traction model and braking model. So, this paper represents the results of the train performance analysis.

• Proceedings of the KSME Conference
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1595-1600
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• 2007

It is necessary a simple helicopter design and performance analysis program for a stage of helicopter conceptual design. To meet that needs, we have developed a program which is simply used to estimate helicopter configuration and performance. The program developed by this study is composed of Requirement, Mission profile Analysis, Size, Aerodynamic, Trim, Propulsion, Weight, and Performance modules, and each modules carry out operations for a given flight condition. In this study, we validate this analysis program in 9,500 1bs and 22,000 1bs helicopters and estimate design configuration and performance of 16,000 1b helicopter. And We can use this program to optimization process for Helicopter MDO framework.