• 무역상무연구
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• 제19권
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• pp.139-166
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• 2003

The purpose of this paper is to examine whether the international electronic payment system through IDENTRUS can be active in the future or not. For this purpose, we have reviewed the various aspects of the typical systems : their types, operational mechanisms and actual limitations in real trade. Then we have proceeded to examine the distinguished features of IDENTRUS in terms of operational procedures and characteristics by comparing to other systems. Specially as the preconditions of activation, the possibilities of cost down, time reduction, risk hedging and operational efficiency have been studied. Thus we are not sure that the IDENTRUS will have a position as a main stream in the future electronic payment system, but this system would contribute positively to the establishment of electronic payment system if some functional additions will follow.

• 한국경영과학회지
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• 제23권4호
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• pp.33-51
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• 1998

The industrial operation is one of the three basic modes of shipping operation with liner and Tramp operations. Industrial operators usually control vessels of their own or on a time charter to minimize the cost of shipping their cargoes. Such operations abound in shipping of bulk commodities, such as oil, chemicals and ores. This work is concerned with an operational optimization analysis of the fleet owned by a major oil company. a typical industrial operator. The operational optimization problem of the fleet of a major oil company is divided Into two phase problem. The front end corresponds to the optimization problem of the transportation of crude oil. product mix. and the distribution of product oil to comply with the demand of the market. The back end tackles the scheduling optimization problem of the fleet to meet the seaborne transportation demand derived from the front end. A case study reflecting the practices of an international major oil company is demonstrated to make clear the underlying ideas.

• 산업경영시스템학회지
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• 제21권48호
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• pp.241-251
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• 1998

The purpose of this study is to evaluate the relative importance of seven JIT operational techniques in Domestic industries. These techniques are used to improve manufacturing effectiveness and efficiency such as : Setup time reduction, Kanban, Multi-functional worker, U type layout, Andon(line stop), Atonomation, and Smoothing production. The new analytic hierarchy process(AHP) model is used in order to evaluate the relative importance of the seven JIT operational techniques which are used to increase the manufacturing effectiveness and efficiency. To aggregate the multi-divisions priorities, in this paper, we suggest a way which decision maker can exclude outlier matrix from group by using the concept of the compatibility in AHP.

• 한국신뢰성학회지:신뢰성응용연구
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• 제4권2호
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• pp.91-104
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• 2004

In this paper we consider the concurrent spare part(CSP) requirements problem of new equipment system. When a part fails, the part is replaced and the repair of failed part is impossible and cannibalization is allowed. We assume that the failure of a part knows a Poisson process. The operational availability concept in CSP is defined, and derive a formula to calculate the operational availability using expected machine operating time during CSP period. A mathematical model is derived for making an CSP requirement determination subject to the constraint of satisfying any given operational availability limitation and an heuristic solution search procedure is derived. An illustrative example is shown to explain the solution procedure.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.1061-1064
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• 2009

The objective of this study is to find the optimal operational planning of the hybrid cooling system, which is combined by ice storage system and the absorption chiller. The optimization technique used in this study is dynamic programming. The objective function is summed cost during a day including charge and discharge periods of ice storage system and operation time of absorption chiller. Assuming that initially ice storage tank is stored fully and the cooling load is perfectly predicted for the operational planning. This method provides the most efficient and economic combination of equipment operational planning for cooling with respect to energy consumption cost.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1995년도 추계학술발표회논문집(1)
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• pp.423-428
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• 1995

Simulation models have been developed to predict the overall behavior of the CANDU plant systems during normal operational transients. For real time simulation purpose, simplified thermal hydraulic models are applied with appropriate system control logics, which include primary heat transport system solver with its component models and secondary side system models. The secondary side models are mainly used to provide boundary conditions for primary system calculation and to accomodate plant power control logics. Also, for the effective use of simulation package, hardware oriented basic simulation network has been established with appropriate graphic display system. Through validation with typical plant power maneuvering cases using proven plant performance analysis computer code, the present simulation package shows reasonable capability in the prediction of the dynamic behavior of plant variables during operational transients of CANDU plant, which means that this simulation tool can be utilized as a basic framework for full scope simulation network through further improvements.

• Computers and Concrete
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• 제12권1호
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• pp.79-90
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• 2013

In this study, dynamic characteristics such as natural frequencies, mode shapes and damping ratios of RC frame is determined for different construction stages using Operational Modal Analyses method under ambient vibration. Full scaled, one bay and one story RC frames are selected as an application for different construction stages such as plane, brick in-filled and brick in-filled with plaster. The RC frame is vibrated by natural excitations with small impact effects and the response signals are measured using sensitive accelerometers during ambient vibration tests. Measurement time-frequency span and effective mode number are determined by considering similar studies in literature. Sensitive seismic accelerometers are used to collect signals obtained from the experimental tests. To obtain experimental dynamic characteristics, output-only system identification technique is employed namely; Enhanced Frequency Domain Decomposition technique in the frequency domain. It is demonstrated that the ambient vibration measurements are enough to identify the most significant modes of RC frames.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 추계학술대회 논문집 전력기술부문
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• pp.134-136
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• 2002

In April of 2000, the Korea Power Exchange(KPX) was introduced into Korea electricity market. The purpose of this paper is to describe how the system operator indicates operational risks between the transmission planning and the supply and demand growth to make the market "work" and manage the power system in real time. This paper describes the experiences of kpx about the indication of operational risks including, for example, contingency analysis, voltage profile and fault capacity of three-phase short current.

• 산업경영시스템학회지
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• 제28권1호
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• pp.97-104
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• 2005

Considered is the concurrent spare part(CSP) requirements problem of new equipment system. In the considered system, when a part fails, the part cannot be repaired and should be replaced. In addition, cannibalization is allowed. It is assumed that the failure of a part follows a Poisson process. The operational availability concept in CSP is defined, and a formula is derived to calculate the operational availability using expected machine operating time during CSP period. The problem is formulated as the operational availability maximization problem with available budget constraint and a heuristic solution search procedure is developed. An illustrative example is shown to explain the solution procedure.

• 대한안전경영과학회지
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• 제8권3호
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• pp.103-114
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• 2006

A cross docking operation involves multiple trucks (known as inbound trucks) that deliver items from suppliers to a distribution center and multiple trucks (known as outbound trucks) that ship items from the distribution center to customers. Based on customer demands, an inbound truck may have its items transferred to multiple outbound trucks. Similarly, an outbound truck can receive its consignments from multiple inbound trucks. A unique characteristic of a cross docking system is the absence or prohibition of long term storage of items at the distribution center. Items delivered to the distribution center from suppliers are shipped to customers as soon as possible without being placed in storage in the distribution center. The objective of this paper is to develop the optimal operational strategy for finding the best truck docking sequence for both inbound and outbound trucks in order to minimize total operation time where a temporary storage area is not available in a cross docking system.