• Steel and Composite Structures
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• 제27권5호
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• pp.633-646
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• 2018

This study investigated the seismic performance of a hybrid damper composed of a steel slit plate and friction pads, and an optimum retrofit scheme was developed based on life cycle cost. A sample hybrid damper was tested under cyclic loading to confirm its validity as a damping device and to construct its nonlinear analysis model. The effectiveness of the optimum damper distribution schemes was investigated by comparing the seismic fragility and the life cycle costs of the model structure before and after the retrofit. The test results showed that the damper behaved stably throughout the loading history. Numerical analysis results showed that the slit-friction hybrid dampers optimally distributed based on life cycle cost proved to be effective in minimizing the failure probability and the repair cost after earthquakes.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 2008년도 추계학술대회 및 정기총회
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• pp.448-452
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• 2008

Organization wishes to develop newer and more complex system according as social structure is more complex and a technology develops more. Therefore, field of system engineering in development of new system is realized by all-important essential boundary. However cost of SE have considered restrictively being not about SE cost having applied SE. About this problem, this study provides COSYSMO as model for SE cost estimation, as the application example, estimate SE cost for smart UAV system applying COSYSMO in PRICE Trueplanner.

• 산업경영시스템학회지
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• 제23권58호
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• pp.17-27
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• 2000

In FMS where tool movement policy is adopted, a mathematical model has been developed which determines the selection of a tool type for each operation and tool loading-part assignment simultaneouly. The objective is to minimize the total cost of operation including machining time cost, tool cost, tool replacement and loading time cost, and tool change time cost. Due to the complexity of the problem, an approximate solution procedure has been developed utilizing the special structure of the model. Tool selection was determined first to allocate one tool type to each operation considering more than one tool type alternatives for each operation. Tool loading-part assignment was determined to minimize tile total number of tool changes due to part mix based on the tool selection.

• 한국국방경영분석학회지
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• 제25권2호
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• pp.144-157
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• 1999

In this paper, we consider a new preventive replacement policy for the system which deteriorates while it is in operation with an increasing failure rate. The system is subject to two types of failure. A type 1 failure is repairable while a type 2 failure is not repairable. In the new policy, a system is replaced at the age of $t_p$ or at the instant the$\textsc{k}^{th}$ type 1 failure occurs, whichever comes first. However, if a type 2 failure occurs before a preventive replacement is performed, a failure replacement should be made. We assume that a type 1 failure can be rectified with a minimal repair. We also assume that a replacement takes a non-negligible amount of time while a minimal repair takes a negligible amount of time. Under a cost structure which includes a preventive replacement cost, a failure replacement cost and a minimal repair cost, we develop a model to find the optimal ($\textsc{k},t_p$) policy which minimizes the expected cost per unit time in the long run while satisfying a system availability constraint.

• 에너지공학
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• 제1권1호
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• pp.87-96
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• 1992

열교환기의 설치비 및 연간 비용에 주된 영향을 미치는 유틸리티의 소비와 열 교환 장치 수의 최소화를 목적으로 하여 경험법칙을 기초로 한 열교환망 합성 방법을 제안하였다. 본 연구에서 제안하는 열교환망 합성 알고리즘의 특징은 축소된 부문제 생성 기법과 부문제의 해를 구하는 방법에 있으며, 제안한 방법을 문헌에 실린 열교환망 합성 문제에 적용한 결과 이전의 결과보다 열교환장치 및 흐름의 분기등이 감소한 결과를 얻음으로써 본 방법의 우수성을 확인할 수 있었다.

• 산업공학
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• 제18권2호
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• pp.184-192
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• 2005

In recent research there has been intense interest in understanding how real option valuation (ROV) approaches might usefully complement conventional discounted cash flow (DCF) techniques. However, investment decision makers in a real world have been worried about adopting the ROV approaches mainly because of difficulty in technically understanding the theory of the ROV approaches as indicated by many researchers. With this difficulty in mind, we propose the opportunity cost model as another discrete-time model to value a deferral option. The main advantage of observing a real options value in terms of the opportunity cost concept is to provide a technique for practitioners to estimate a wide range of real options values without sticking to a financial option modelling. The fundamental ground for developing the opportunity cost model proposed in this paper lies in the work of dissecting the structure of the real options value into three categories: capital gain, expected opportunity loss, and expected opportunity gain. At the end of the paper, we will present a short illustrative example to demonstrate the applicability of the model.

• 대한산업공학회지
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• 제21권4호
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• pp.555-570
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• 1995

We consider a preventive replacement policy for a cold-standby system with N components, in which only one component is in operation at a time. If the component in operation fails, a standby component is immediately switched into operation. If all components fail, the system fails. The system is inspected at random poins in time to determine whether it is to be replaced or not. If the number of failed components at the time of inspection exceeds a threshold value r, the system is replaced. Otherwise the decision is put off until the next inspection point arrives. Under the cost structure which includes a replacement cost, a system down-time cost and a holding cost of the components, we develop an efficient procedure to find the optimal control values N and r, which minimize the expected cost per unit time.

• 한국군사과학기술학회지
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• 제13권3호
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• pp.431-437
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• 2010

It's strongly needed to minimize the logistics response time for supporting military operations in wartime. In this paper, we suggest the ILP formulation for minimizing logistics response time in wartime. Main structure of this formulation is based on the traveling purchaser problem(TPP) which is a generalized form of the well-known traveling salesman problem(TSP). In the case of general TPP, objective function is to minimize the sum of traveling cost and purchase cost. But, in this study, objective function is to minimize traveling cost only. That's why it's more important to minimize traveling cost(time or distance) than purchase cost in wartime. We find out optimal solution of this problem by using ILOG OPL STUDIO(CPLEX v.11.1) and do the sensitive analysis about computing time according to number of operated vehicles.

• International Journal of Internet, Broadcasting and Communication
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• 제13권2호
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• pp.52-59
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• 2021

In this paper, we propose a system that allows small business owners focusing on the restaurant business to easily understand the management situation, and to manage the operation and management centering on the cost of food materials and profits and losses. In general, the metadata structure is different depending on the POS system, so it is necessary to first develop a standardized metadata model for a food material cost management system for small business owners in various industries. For that reason, the system proposed in this paper was applied to the cost management app by referring to the development of a data model using the metadata standard. In addition, in order to implement a cost profit/loss management system for small business owners in the restaurant industry, it was designed to support standardized metadata models from various types of POS systems, and is a hybrid app that can support a smart environment. Interface) was configured.

• Composites Research
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• 제19권1호
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• pp.43-48
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• 2006

High performance fiber reinforced cement composites have better performances than traditional cement based materials, therefore, have been expected as new construction applications such as the materials for construction & bridge structure, repair and rehabilitation applications, anti-collapse applications, anti-noise applications etc. However, they have lots of the problems such as material design, fabrication method and structural analysis. Also, the most serious problems of High performance fiber reinforced cement composites have been expensive initial cost, lack of long-term exposure data. As a result, it is needed that the efforts for lowering the initial cost and accumulation of long-term exposure. There has been hardly assessment results of life cycle cost for HPFRCC in construction field, but some papers showed that total life cycle cost could be profitable if the initial cost could be reduced.