• 상하수도학회지
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• 제31권6호
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• pp.529-537
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• 2017

Membrane filtration process is an advanced water treatment technology that has excellently removes turbidity and microorganisms. However, it is known that it has problems such as low economic efficiency and the operating stability. Therefore, this study was to evaluate on the economical feasibility and operational stability comparison of membrane and sand filtration process in Im-sil drinking water treatment plant. For the economic analysis of each process, the electricity cost and chemical consumption were compared. In the case of electric power consumption, electricity cost is $68.67KRW/m^3$ for sand filtration and $79.98KRW/m^3$ for membrane filtration, respectively. Therefore, membrane filtration process was about 16% higher than sand filtration process of electricity cost. While, the coagulant usage in the membrane filtration process was 43% lower than the sand filtration process. Thus, comparing the operation costs of the two processes, there is no significant difference in the operating cost of the membrane filtration process and the sand filtration process as $85.94KRW/m^3$ and $79.71KRW/m^3$ respectively (the sum of electricity and chemical cost). As a result of operating the membrane filtration process for 3 years including the winter season and the high turbidity period, the filtrated water turbidity was stable to less than 0.025 NTU irrespective of changes in the turbidity of raw water. And the CIP(Clean In Place) cycle turned out to be more than 1 year. Based on the results of this study, the membrane filtration process showed high performance of water quality, and it was also determined to have the economics and operation stability.

• 한국수자원학회논문집
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• 제44권12호
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• pp.1001-1013
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• 2011

이웃한 상수도시스템의 공급 가능지역이 중첩될 경우, 이들 시스템을 연계함으로써 경제성과 수질 조건을 만족시키는 조건별 용수공급체계를 구축하는 것이 필요하다. 용수수요 조건별 경제적 급수구역과 최적 펌프운영율을 산정하기 위하여 관망수리해석 모형(EPAnet)과 네트워크 최적화모형(KModSim)을 연계 하는 최적 네트워크모형을 개발하였다. 개발된 최적 네트워크 모형을 사등가압장, 구천댐 그리고 연초댐의 3개 상수원이 존재하는 거제지역 상수도시스템에 적용하고 2007년 운영 결과와 비교하는 방법으로 모형을 검정하였다. 최적 네트워크 모형의 적용성을 검토하기 위하여, 2011년 용수자료를 이용하여경제적급수구역변경에따른펌프운영및 수질의 적정성을평가 하였다. 평가결과본 모형은 수량, 경제성 그리고 수질을 모두 만족하는 최적해를 구하는 것으로 나타나 송배수계통간의 최적 설계 혹은 최적연계운영율을 구하기 위한 모형으로 활용이 가능하다.

• 전기학회논문지
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• 제59권12호
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• pp.2131-2134
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• 2010

In this paper, the on-line system schemes for coordinated control system of multiple FACTS were presented to enhance the voltage stability around the metropolitan areas. In order to coordinated control system of FACTS devices, MFC on-line system calculates the optimal set point(Vref, Qrev) of FACTS devices using the coordinated control algorithm with real time network data which is transferred from SCADA/EMS system. If the system is unstable after contingencies, the new operation set-point of FACTS would be determined using bus sensitivity from tangent vector at voltage instability point. Otherwise, we would determine the new operation set-point of FACTS for considering economical operation, like as active power loss minimization using Optimal Power Flow algorithm. As the test, MFC(Multiple FACTS Coordinated control) on-line system will be installed in Korea power system.

• 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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• 제8권2호
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• pp.43-50
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• 2002

By reason of development of anesthesia, advent of new surgical operation type and change of hygiene criterion and economical index is increasing recently request about alteration of existing unit or new surgical operation-unit type. The purpose of this study is to provide of architectural planning program for the type decision and the scale computation of operating-unit in healthcare facilities. As a result of this study, presented program of six type according to surgical operation process including space and time side.

• 전기학회논문지
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• 제57권10호
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• pp.1726-1730
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• 2008

In this paper, the application schemes for coordinated control system of multiple FACTS were presented to enhance the voltage stability around the metropolitan areas. In order to coordinated control of FACTS devices, f-V analysis method which is one of the indices for voltage stability was performed with real time network data which is transferred from SCADA/EMS system. If the system is unstable after contingencies, the new operation set-point of FACTS would be determined using bus sensitivity from tangent vector at voltage instability point. Otherwise, we would determine the new operation set-point of FACTS for considering economical operation, like as active power loss minimization using Optimal Power Flow algorithm. In simulation, the SCADA/EMS 2007's data are used for studying the coordinated control algorithm of multiple FACTS devices that is installed or will be installed in KOREA power system

• 대한기계학회논문집A
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• 제33권10호
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• pp.991-1004
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• 2009

Operating experience of the various components in the nuclear power plants has shown that a variety of degradation mechanisms can occur during operation. Therefore, the accurate lifetime evaluation and systematic management are very important for the safe as well as the economical operation of the nuclear power plants. In this paper, the characteristics of a total of 17 degradation mechanisms were reviewed and the plausible degradation mechanisms such as stress corrosion cracking, fatigue, irradiation embrittlement, and so on, were identified. Also, the lifetime evaluation technologies which have been developed for the application to the domestic nuclear power plants are described. In addition, a total of 48 aging management programs which have been established for the safe operation of the various components are explained.

• Journal of Advanced Marine Engineering and Technology
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• 제32권5호
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• pp.677-683
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• 2008

The electric propulsion system us closely related with the economical efficiency of ship operation. Fuel efficiency is mainly decided by propulsion system such as diesel engine, propulsion motor and steam turbine. The hybrid propulsion system for fishing boat consists of diesel engine and battery as propulsion power source. This paper is to design battery capacity according to power consumption with ship operation condition, and to test the power consumption of model ship in the circulating water channel. As a result. it can be known that the optimum ship operation condition affects the fuel efficiency.

• KEPCO Journal on Electric Power and Energy
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• 제2권2호
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• pp.269-272
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• 2016

Distribution management system or microgrid energy management system plays an important role in monitoring, operation and control of electrical distribution systems by utilizing IT infrastructure. Nowadays, the rapid increase of the distributed resources makes the conventional management system have some additional functionality for the reliable operation due to intermittent renewables and the efficient operation on the economical purpose. In this paper, the brief standard software functional requirements of microgrid energy management system are provided through survey of the recent commercial products of the major vendors, and furthermore the architectures of microgrid energy management system are provided in comparison with major suppliers' microgrid energy management system. The summary of investigation will be able to make the developers and researchers focus on the specific functionality in the real world.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2005년도 전력전자학술대회 논문집
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• pp.501-503
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• 2005

The improvement of load following operation of the thermal power plant is influenced to the electrical quality. Analysis of boiler, turbine, and governor system, and the study of control algorithm are preceded. The thermal power plant is operated by various control systems. In the case of faulty governor system, it takes long days to solve the problem and impossible to repair the mechanism without outage. A non-planned out-age is taken into consideration because of economical power production. In this paper, to clear the continuous swings of an old turbine governor system(YEOSU #1), the trend, the control logic, and the hydraulic mechanism are analyzed, and then the control circuit with ADAPT function and the 1st order lag circuit are inserted and modified. After that, the power plant comes to automatic governor control operation.

• 전기학회논문지
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• 제64권10호
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• pp.1493-1500
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• 2015

For efficient and economical train operation in low-density railway line, on-board oriented train control system, which reduces expensive wayside equipment, is being developed. In this paper, we discuss a tram signal priority strategy which enables efficient and safe train operation when the developing system is applied to train-tram railway environment. Based on the well-known transit signal priority strategies, we develop a tram signal priority algorithm and conduct simulations by using model-based systems engineering (MBSE) tool. Various considerations such as operation procedure, linkage to existing road traffic system, applicability with respect to crossroad types, and so on, are also dealt with.