• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.259-260
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• 2006

City Train Technology that is large and complex system and consists of mechanical, electronic, electric, materials, computer, communication, civil/track etc. is very important area of railway industry, national fundamental industry. The standardization of city train system as a public transportation method and foundation of national economy is very important in order to do effective operation and to get fundamental technology, and the information system of the standards is required to operate the city train system effectively. By building data base of city train system design knowledge using computer-aided system engineering tool-Cradle, the system development issues and the design solutions are used by all engaged persons, and are managed by modeling and documentation. And this system will support architecture design consistently and effectively by applying this system to formalize early development process, to system requirements and configuration management, to system interface analysis and management and to system behavior analysis etc.. This study is for construction of data base of system design knowledge through making data base of many kinds of standards using CASE tool based on System Engineering Process, and introduces a model to support concurrent engineering for all engineers involved in system development allowing access to standard DB through Web from anywhere and at anytime.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1993년도 가을 학술발표회논문집
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• pp.240-247
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• 1993

The precise prediction of reserved carrying capacity of bridge as a system is extremely difficult especially when the bridges are highly redundant and significantly deteriorated or damaged. This paper is intended to propose a new approach for the evaluation of reserved system carrying capacity of bridges in terms of equivalent system-strength, which may be defined as a bridge system-strength corresponding to the system reliability of the bridge. This can be derived from an inverse process based on the concept of FOSM form of system reliability index. It may be emphasized that this approach is very useful for the evaluation of the deterministic system redundancy and reserve strength which are measured in terms of either probabilistic system redundancy factor and reserve factor or deterministic system redundancy factor and reserve factor. The system reliability of bridges is formulated as a parallel-series model obtained from the FAM(Failure Mode Approach) based on the major failure mechanisms. AFOSM and IST methods are used for the reliability analysis of the proposed models. The proposed approach and method for the system redundancy and reserve safety/strength are applied to the safety assessment of actual RC and steel box-girder bridges. The results of the evaluation of reserved system safety or bridge system-strength in terms of the system redundancy and the system safety/strength are significantly different from those of element reliability-based or conventional methods.

• 한국정밀공학회지
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• 제18권10호
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• pp.69-75
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• 2001

Systems engineering has been utilized in system development primarily for large-scale projects or commercial large-scale systems during the last several decades. We can understand why it would be useful to apply systems engineering to the development of a relatively small system. However, it is difficult to effectively carry out a project due to the complexity in applying the methods of systems engineering. To apply systems engineering to the development of a small system, the system engineering processes should be tailored. We established a requirements driven system design process(RDSDP) that can effectively carry out the system design far a small system. RDSDP is a system design process that treats all the requirements thoroughly and effectively. This is applied by the designer according to a standardized and systematized process during the first phase in design, in which system specifications are made. By using RDSDP, we can affect a reduction of the number of redesign phases in the process of the system design, shorten the period for to make specification, which will then cause the system to succeed in the actual application.

• 전산구조공학
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• 제10권4호
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• pp.251-265
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• 1997

해양계선시스템(offshore mooring system)의 거동을 구분적선형시스템(piecewise-linear system)을 이용하여 분석하였다. 계선시스템의 복원력을 유도하고 거기에 상응하는 근사치 구분적선형시스템의 복원력을 구하여 두 시스템의 복원력을 비교하였다. 다양한 파력 하에서의 계선시스템의 응답거동을 분석하였다. 시스템의 비선형정도 및 매개변수의 영향에 대하여 집중적으로 연구하였다. 시스템의 응답거동의 특성은 포인케어맵(Poincare map)을 통하여 확인하였다. 구분적선형시스템을 이용하여 분석한 결과, 계선시스템은 일반 조화, 열조화 및 복잡한 비선형거동인 chaos를 포함한 다양한 응답거동을 갖음을 알아냈다. 여러 값의 매개변수를 적용하여 시스템의 응답거동에 미치는 영향을 알아냈으며, 매개변수지도를 통하여 응답거동의 영역을 확인하였다.

• KSBB Journal
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• 제13권4호
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• pp.411-417
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• 1998

The possibility of application of membrane type immobilized adsorbent to the fed-batch or perfusion culture system with anchorage-independent cells as well as batch system was investigated. The improvement in cell density and cell viability due to the combination of immobilized adsorbent with each culture system was evaluated for the investigation, and the optimum culture system employing immobilized adsorbent system was suggested based on the results. It was observed that the system with immobilized adsorbent showed better cell growth and cell viability than that without immobilized adsorbent in every operation system of batch, fed-batch, and perfusion. In case of batch system, 200% improvement of maximum cell density was observed in the system where ammonium chloride was added on purpose. And 50% improvement of maximum cell density was observed in the fed-batch system where ammonium ion accumulates significantly, while small increase in maximum cell density was observed in the perfusion system where dilution of waste byproducts exists. Especially, the fed-batch system showed the most significant improvement on cell growth because both compensation of nutrient and removal of ammonium ion occurred simultaneously in the system. Therefore a combined system of immobilized adsorbent and fed-batch operation could be suggested as an optimum system with in situ removal of ammonium ion.

• 한국안전학회지
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• 제22권1호
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• pp.7-12
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• 2007

There are two kinds of design process for sprinkler system. one is pipe schedule system and the other is hydraulically designed system. We have inefficient results when we design by hydraulically designed system because the design process for sprinkler system is restricted by domestic fire code. Therefore, it is essential to do an introduction of hydraulically designed system which is based on engineering for enhancing reliability and efficiency of sprinkler system. This study presents points at issue by comparing and studying design standards of sprinkler system from Korea, Japan and NFPA, and presents improvement plans of national fire safety code of sprinkler system by processing, comparing and analyzing designs according to piping schedule and hydraulically designed system about domestic objects. Installation standards of sprinkler system have to be applied not by object buildings but by hazard classification. It is hard to design an efficient sprinkler system for fire control when water supply requirement of sprinkler systems allocated according to a size of a building because the same purpose but other buildings may request more water requirement or less. We should sublate the pipe schedule system from national fire safety code and need to introduce the hydraulically designed system. The pipe schedule system presents easy access because it is based on the forecasted engineering calculations but it is applied to only small buildings like NFPA due to its low reliability.

• 전기학회논문지P
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• 제53권2호
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• pp.89-93
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• 2004

Supervisory Control And Data Acquisition(SCADA) of electric power system refersto the system that displays, monitors and executes the control commands for remote electric power system. KNR's existing electric power control system is built on UNIX platform such that it costs more for system construction, and people with UNIX skills can only be an operator who controls and manages the system. Moreover, since the system is mainly operated in local offices, system operators must communicate with local operators to investigate the cause of the accident and react the accident every time the system fails. As a new integrated SCADA system is constructed, establishment of small-unit electric power control system, that alters local electric power control system in designated stations, is required. In this study, the electric power control system, which accommodates all functions of UNIX-based SCADA system and facilitates operation and even maintenance for local operators, is to be developed. In order to develop small-unit electric power control system, the industrial automation program, "Cimon", is used. The small-unit electric power control system that accommodatesRTU and newly installed electronic switchboard is being developed and tested at Chulam station of KNR.

• 동력기계공학회지
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• 제13권4호
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• pp.68-73
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• 2009

The mathematical model has a different response character with the real system because this mathematical model has the modeling errors and the imprecise value of system's parameters. Therefore to find the value of system parameters as possible as near by real value in the model is necessary to design the controlled system. This study concern about the identification method to estimate the parameter for the magnetic bearing system with RCGA(Real Coded Genetic Algorithm). Firstly, we will get the mathematical model from the current amplifier circuit and the magnetic bearing system. Secondly we will get the step response data in this circuit and system. Finally, we will estimate the unknown parameter's value from the data.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.261-264
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• 1997

A contactless eddy current type braking system is developed to take advantages of the recent brake system which uses hydraulic force can show high efficiency in a certain velocity region, but not in a high velocity region, and has initial response delay time and pressure build-up time which make stopping distance longer. These are the limits of mechanical brake system of a contact type, which makes a concept brake system required. So, in this paper, the contactless brake system .of a inductive current type is chosen instead of hydraulic brake system. This brake system can be used almost forever for being no wear and contributed to lightening weight of a vehicle. Besides, the contactless brake system can be used as that of electric or solar car with anti-lock brake system. The analysis of induced electromotive force and braking torque obtained with theoretical approximate model, the design of a braking system and a nonlinear controller, and the results of simulation of the ABS, experiment are included.

• 한국군사과학기술학회지
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• 제21권5호
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• pp.675-683
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• 2018

In this paper, we have proposed a design and verification methods of electrical system and power loads for unmaned aeriel vehicles(UAVs) through electrical load analysis. In order to meet a UAV system requirement and electrical system specifications, we have designed an electrical power system for efficient power supply and distribution and have theoretically analyzed the power loads according to the power consumption and power bus design of UAV. Using electrical system rig, the designed electrical power system has been experimentally verified. Also, we have performed several flight tests to verify the UAV electrical system and power loads. It is concluded that the proposed design and verification method of electrical system for UAV system.