• 한국수자원학회:학술대회논문집
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• 한국수자원학회 1992년도 수공학연구발표회논문집
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• pp.479-489
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• 1992

A mathematical model for a long range water supply planning is develoted as a dynamic capacitated facility location problem, in which operation costs and two types of fixed costs are considered. The fixed costs are for water supply systems such as dams and reservoirs and for water conveyance systems of waterways or conduits from each water supply points. A Spreadsheet model is developed to support the efficiency of user interface and to implement a heuristic solution procedure. The proposed solution procedure utilizes SOLVER tool and it has been applied to a system with fictitious data but with reality and applicability in mind. As a result of the mathematical analysis, not only the most economic construction timings of surface water supply facilities and distribution systems but also the most economical water supply operating patterns are identified.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 2004년도 춘계공동학술대회 논문집
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• pp.475-478
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• 2004

Tool costs can comprise a significant part of the total operating costs of Flexible Manufacturing Systems. We address the problem of determining the optimal processing times of individual operations and routing mix in FMSs with multiple routes for each part type in order to minimize tool cost, subject to meeting a throughput constraint for each part type. The problem is formulated as a nonlinear program superimposed on a closed queueing network of the FMSs under consideration. Numerical examples reveal the potential of our approach for significant saving in tool costs.

• 대한산업공학회지
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• 제2권1호
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• pp.93-100
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• 1976

Given a fixed production process and facility capacity, the ability to respond to market fluctuations in terms of changes in production, work force, and inventory is the major task of production management. The costs involved are primarily payroll (regular and overtime), inventory carrying, and hiring and firing. The magnitude of these costs is usually a significant portion of the operating costs of the firm and consequently a small percentage saving due to astute aggregate scheduling can mean substantial absolute saving. At least three demonstrably optimal techniques have been developed for solving this aggregate scheduling problem. These three optimal are apparently LDR, PPP, and SDR. By combining these three different approaches, another optimal solution was obtained by me. I call this CDR (Combined Decision Rule). This approach appears to be useful. This approach may be generalizable to aggregate scheduling involving a short term resources.

• 드라이브 ㆍ 컨트롤
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• 제9권2호
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• pp.46-53
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• 2012

This paper explains how eliminating contamination from the manufacturing processes will lead to better product quality and hence the need for reworking, a trouble free commissioning period and greatly improved production efficiency. All of these will reduce costs and energy usage. It will also ensure that the product is delivered to the customer in a condition that will ensure improved reliability and longer life, again reducing both energy and other operating costs. Correctly designing the contamination control measures will achieve and maintain the level of fluid cleanliness that is required by the end user. The filter is critical to cleanliness management and should be selected with the same degree of thought and consideration as for other major components. This paper explains the role that Cleanliness Management plays in the reducing the carbon footprint of systems and processes by making them perform more efficiently for longer periods. It also examines two differing ways of selecting filters to incorporate the features of newer designs, and shows how significant savings in the costs of ownership can be achieved using these approaches.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2003년도 가을 학술논문집
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• pp.636-641
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• 2003

본 연구에서는 처분원가산정과 관련한 원가대상의 비율을 분석하였다. 분석결과에 따르면, 총 원가에서 운영비의 비율이 가장 높은 것으로 나타났다. 처분원가는 원가구성 측면에서 일반적인 제품원가 구조와는 많은 차이가 있다. 제품원가는 직접재료비, 직접노무비, 제조간접비로 구분되는 반면에 처분원가인자는 크게 기술적 인자와 비기술적 인자로 구성된다.

• 한국항공운항학회지
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• 제26권4호
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• pp.142-148
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• 2018

In recent years, Korea's aviation industry has been developing rapidly due to the emergence of low-cost airlines. In order to survive in such competition, airlines are making various efforts to save the operation cost as much as possible. Fuel costs account for more than 25% of operating costs. For airlines, reducing aircraft fuel costs is an important part of improving profitability. In this study, analyzing the difference weight between flightplan and W&B Manifest for calculated the fuel that was unnecessarily loaded. As a method to calculate the unnecessary fuel was used by Airbus company flight planning program.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.1840-1845
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• 2005

The SoC and digital technology development recently enabled the emergence of information devices and control devices because the SoC present many advantages such as lower power consumption, greater reliability, and lower cost. It is required to use an embedded operating system for building control systems. So far, the Real-Time operating system is widely used to implement a Real-Time system since it meets developer's requirements. However, Real-Time operating systems reveal a lack of standards, expensive development, and license costs. Embedded Linux is able to overcome these disadvantages. In this paper, the implementation of control system platform using Real-Time Embedded Linux is described. As a control system platform, we use XScale of a Soc and build Real-Time control platform using RTAI and Real-Time device driver. Finally, we address the feasibility study of the Real-Time Embedded Linux as a Real-Time operating system for mobile robots.

• 제어로봇시스템학회논문지
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• 제3권4호
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• pp.373-380
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• 1997

In order to implement the real-time operating systems for robot controller, this paper proposes a systematic method for implementing the real-time kernel under the DOS environment. So far, we designed the robot control software and its own operating system simultaneously. Though robot operating systems have simple structure, it allows the developer to have a surplus time and effort to implement complete robot systems. In addition to this, in most cases of this type, operating systems does not support multitasking function, thus, low level hardware interrupts are used for real-time execution. Subsequently, some kinds of real-time tasks are hard to implement under this environment. Nowadays, the operating systems for robot controller requires multitasking functions, intertask communication and task synchronization mechanism, and rigorous real-time responsiveness. Thus, we propose an effective and low costs real-time systems for robot controller satisfying the various real-time characteristics. The proposed real-time systems are verified through real implementation.

• 한국물환경학회지
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• 제22권5호
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• pp.905-912
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• 2006

In this paper, simulation methods of the system dynamics model developed by Das et al. (1997) for activated-sludge wastewater treatment plants are illustrated in an attempt to determine the operating rules and the policies related to capacity expansion of an activated-sludge wastewater treatment plant. For existing conditions, the analyses were performed by varying activated-sludge return rate to observe changes in effluent water quality and treatment efficiency. The effluent water quality is also analyzed for various average daily inflow conditions and activated-sludge return rates. As a result, without expanding the aeration tank, maximum average daily inflow that can satisfy the effluent water quality standard of BOD $0.02kg/m^3$ was determined as $2,840m^3/hr$, subject to 100% of activated-sludge return rate while other factors remain constant. When the activated-sludge return rate is less than 100%, expansion of the aeration tank is necessary and minimum sizes of the aeration tank to satisfy the effluent water quality standard were determined for various activated-sludge return rates. In addition, the total operating and maintenance as well as unit treatment cost regression equations for activated-sludge wastewater treatment plants are suggested by using the cost data that are obtained from Water and Wastewater Division, Ministry of Environment. The regression analyses showed that the economies of scale phenomena exist in the operating and maintenance costs of activated-sludge wastewater treatment plants.

• 대한토목학회논문집
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• 제43권5호
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• pp.651-657
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• 2023

국내외 철도사업에서 철도의 신규 건설과 더불어 기존선의 개량을 통한 증속, 고속화 사업도 큰 비중을 차지고 있다. 특히 해외의 개발도상국은 경제수준을 고려할 때 고속철도의 건설은 막대한 규모의 예산소요와 수요를 고려할 때 한계가 있어, 기존 철도의 선형개량을 통한 증속사업이 실현가능성이 높은 것으로 판단하고 있다. 본 연구에서는 선형개량을 통향 기존선의 증속사업의 효율적 기획과 분석을 위하여, 기존에 신규 철도 건설사업 분석에 활용되고 있는 지능형 철도선형계획 프로그램(ei-Rail)에 선형개량사업 분석 기능을 추가할 수 있는 방법론을 개발하였다. 수치지도 또는 기존의 위성사진 자료를 기반의 베이스 맵에 기존의 철도선형을 입력하고, 목표속도등 선형개량사업의 목표를 입력하면, 사업의 비용과 도면, 증속효과 분석 결과 등을 자동적으로 제시함으로써, 철도선형개량 사업의 기획과 분석을 효율적으로 수행할 수 있는 도구로 활용될 수 있도록 하였다.