• 항공우주시스템공학회지
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• 제14권6호
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• pp.79-84
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• 2020

Cooler driver electronics (CDE) for maintaining low temperature of the satellite payload IR sensor consists of a compressor that has a pulsation current load condition when it is operated. This pulsation current produces large voltage fluctuation, which affects both load and regulated bus stability. Thus, CDE power conditioning system consists of a primary bus, infrared power distribution unit for battery charging and protection, reverse current protection diode, and battery, which is used as a buffer. In this study, the operational mode analysis is performed by each part with equivalent impedance modeling verified through system level simulation. From this mode analysis, the safety margin for state of charge and open circuit voltage of the battery is determined for satisfying the minimum operational voltage of the CDE load.

• Earthquakes and Structures
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• 제8권4호
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• pp.859-887
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• 2015

Structural health monitoring (SHM) has gained in popularity in recent years since it can assess the performance and condition of instrumented structures in real time and provide valuable information to the asset's manager and owner. Operational modal analysis plays an important role in SHM and it involves the determination of natural frequencies, damping ratios and mode shapes of a constructed structure based on measured dynamic data. This paper presents the operational modal analysis and seismic response characterization of the Tsing Ma Suspension Bridge of 2,160 m long subjected to different earthquake events. Three kinds of events, i.e., short-distance, middle-distance and long-distance earthquakes are taken into account. A fast Bayesian modal identification method is used to carry out the operational modal analysis. The modal properties of the bridge are identified and compared by use of the field monitoring data acquired before and after the earthquake for each type of the events. Research emphasis is given on identifying the predominant modes of the seismic responses in the deck during short-distance, middle-distance and long-distance earthquakes, respectively, and characterizing the response pattern of various structural portions (deck, towers, main cables, etc.) under different types of earthquakes. Since the bridge is over 2,000 m long, the seismic wave would arrive at the tower/anchorage basements of the two side spans at different time instants. The behaviors of structural dynamic responses on the Tsing Yi side span and on the Ma Wan side span under each type of the earthquake events are compared. The results obtained from this study would be beneficial to the seismic design of future long-span bridges to be built around Hong Kong (e.g., the Hong Kong-Zhuhai-Macau Bridge).

• Earthquakes and Structures
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• 제19권1호
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• pp.45-57
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• 2020

This paper presents the experimental application of a new method for seismic vulnerability assessment of buildings recently introduced in literature, the SMAV (Seismic Model Ambient Vibration) methodology with reference to their operational limit state. The importance of this kind of evaluation arises from the civil protection necessity that some buildings, considered strategic for seismic emergency management, should retain their functionality also after a destructive earthquake. They do not suffer such damage as to compromise the operation within a framework of assessment of the overall capacity of the urban system. To this end, for the characterization of their operational vulnerability, a Structural Operational Index (IOPS) has been considered. In particular, the dynamic environmental vibrations of the two considered strategic buildings, the fire station and the town hall building of a small town in the South of Italy, have been monitored by positioning accelerometers in well-defined points. These measurements were processed through modern Operational Modal Analysis techniques (OMA) in order to identify natural frequencies and modal shapes. Once these parameters have been determined, the structural operational efficiency index of the buildings has been determined evaluating the seismic vulnerability of the strategic structures analyzed. his study aimed to develop a model to accurately predict the acceleration of structural systems during an earthquake.

• 디지털융복합연구
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• 제12권11호
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• pp.23-32
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• 2014

이 연구의 주요 목적은 공공 문화예술기관의 운영역량 분석을 통해 향후 공공 문화예술기관의 활성화 방안 을 제시해 보는 것이었다. 이 연구의 분석 결과를 요약하면 다음과 같다. 첫째, 기존에 공공 문화예술기관의 운영 역량 변수는 (1)예술성, (2)공연의 편의성, (3)조직관리이고, 성과변수는 (4)운영성과인 것으로 나타났다. 둘째, 공공 문화예술기관별로 예술성은 큰 차이가 없으나 공연의 편의성, 조직관리, 운영성과는 차이가 있는 것으로 나타났다. 따라서 향후 진정한 문화예술산업의 발전을 위해서는 기관별로 예술성의 콘텐츠 차별화를 통해 운영성과 및 산업의 활성화를 도모해 나가야 할 것이다. 셋째, 공공 문화예술기관의 운영역량 순위는 예술성이 가장 높으며, 다음은 운영성과, 조직관리, 공연의 편의성 순으로 나타났다. 따라서 공공 문화예술기관의 운영효과를 위한 시스템 개선은 공연의 편의성, 조직관리, 예술성 순으로 역량 개선이 이루어져 나가야함을 시사하고 있다.

• Journal of the Korean Data Analysis Society
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• 제20권6호
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• pp.3003-3014
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• 2018

본 논문은 건설기업 미청구공사 정보의 가치관련성이 해당 건설기업의 효율성 정도에 따라 차별화되는지에 대하여 연구하였다. 미청구공사는 국내 건설기업의 IFRS 도입에 따라 재무상태표의 자산에 표시되는 계정으로서 매출채권적인 성격을 가지는 항목이기는 하지만 추정된 진행률에 연동되어 계산된다는 점 등에서 그 자산성에 의심이 가는 항목이다. 본 논문에서는 미청구공사의 가치관련성이 해당 건설기업의 경영효율성에 따라 차별화된다는 가설을 설정하고 이를 검정하였으며, 검정결과는 다음과 같다. 첫째, 미청구공사는 기업가치와 유의적인 관계가 있는 것으로 나타나 기존 선행연구의 결과들과 일관된 모습을 보였다. 둘째, 미청구공사의 가치관련성은 경영효율성의 정도가 높은 기업에서 더욱 높게 나타나는 것으로 확인되었다. 결국 이 논문은 미청구공사가 단순히 가치관련성을 가진다는 점뿐만 아니라 기업의 효율적 운영정도에 따라 차별화 될 수 있다는 것에 대한 증거를 함께 제시하였다는 점에서 선행연구와 차별화된 연구라고 할 수 있다.

• 한국주거학회논문집
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• 제25권3호
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• pp.131-143
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• 2014

The purpose of this study is to develop an operation manual of resident-driven community program by evaluating community program operation to realize a sustainable apartment complex and vitalize a community. To achieve this purpose, 8 community experts, who are in charge of 42 complexes of 7 autonomous districts among 25 districts in Seoul were interviewed from September 2013 to December 2013. Main results of the study are as follows. 1) Operational problems and improvements are deduced from evaluating operation process of community programs. It is found that smooth cooperation of main operators including a community vitalization association, a resident representative meeting and a control office is the most important. 2) Operation guideline for representative programs are suggested based on analysis of operational characteristics of 3 types of community programs; communication, recycling and environment management, according to program operation elements; material element, programming element, human element and finance element. 3) An operation manual of resident-oriented community program is presented after considering evaluation of operation processes and analysis of 3 types of operational elements of community programs.

• 경영과학
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• 제21권2호
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• pp.111-122
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• 2004

Measuring performance of corporate information system has become one of the core issues in that development of the information system requires substantial amount of investments and the system works as a crucial leverage to enhance competitive edge. Most of the previous researches for performance of the information system have narrow and limited focus on such as the effect of user satisfaction and productivity. This paper suggests a model to measures the comprehensive performance which is classified as user scope (user involvement and satisfaction), operational scope (task productivity, task innovation, customer satisfaction, management control) and efficiency scope (financial performance), and to represent the relationship among the scopes by the path analysis model. Followings are conclusions from statistical hypothesis test of the model: (i) user involvement through user satisfaction has positive effect on all the performances in the operational scope, (ii) task innovation and customer satisfaction in the operational scope has statistically significant impact on financial performance but task productivity and management control do not. This conclusion indicates that task productivity and management control has the long term effect in nature, and evaluation of the information system has managerial implication when it Is measured in comprehensive performance which includes internal operational performances as well as financial performance.

• The Journal of Asian Finance, Economics and Business
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• 제7권2호
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• pp.301-308
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• 2020

This study focuses on determining the impacts of organizational culture on the accounting information system and the operational performance of small and medium-sized enterprises in Ho Chi Minh City. The paper is organized in five parts: introduction, literature review, research methodology, research results, and conclusion and policy implications. Based on the samples of 353 respondents working in small and mediumsized enterprises in Ho Chi Minh City, the research employs both qualitative and quantitative methods to find the answers for research questions. Group discussion, which yields final observed variables of the factors of organizational culture is used for qualitative method. Statistics, assessment of the reliability of Cronbach's Alpha scale, exploratory factor analysis (EFA), confirmatory factor analysis (CFA) and structural equation modeling (SEM) are used for quantitative procedure. The results show that mission, involvement and inconsistency in organizational culture positively affect the accounting information system of small and medium-sized firms in Vietnam. In addition, mission, involvement, adaptability and consistency in organizational culture are found to have positive impacts on the firm operational performance. Another finding of the study is that the accounting information system has a positive effect on operational performance of small and medium-sized firms in Vietnam.

• The Journal of Asian Finance, Economics and Business
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• 제9권5호
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• pp.541-552
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• 2022

This research examines the effects of organizational learning and network involvement, as well as many contextual factors, on power generation businesses' innovation capability and operational success in Vietnam. This research also aims to attest to the moderating roles of top management support and company age, and firm possession type in the power generation industry. This study applied the exploratory factor analysis (EFA) and PLS-SEM approach for data analysis. In this research, we have tested hypotheses with data collected from 132 top managers and other key personnel from power generation companies in Vietnam. The results also attest to the moderating role of top management support on the two relationships between organizational learning - innovation capability and network involvement - innovation capability. Another important finding is that the company age has a negative impact on operational performance but shows a positive moderating role in the relationship between innovation capability and operational performance. This study highlights the central roles of organizational learning and innovation capability in impacting the organizational performance of power generation companies. These companies play a key role in supporting the development of industries in practice. This research also emphasizes the moderating roles of top management support and company age and possession type in practice.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1991년도 하계학술대회 논문집
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• pp.809-812
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• 1991

Two control strategies are proposed for two arm robots; i.e. position-position control and position-force control. For the proof of these control strategies, the stability analysis is conducted with robot dynamics included. First, the closed form dynamic equation of the robot is derived, then it is transformed into the operational space for further analysis. Finally, Liapunov method is applied to the dynamic equation in operational space.