Development of Simplified DNBR Calculation Algorithm using Model-Based Systems Engineering Methodology

Awad, Ibrahim Fathy,Jung, Jae Cheon The Korean Society of Systems Engineering 2018 시스템엔지니어링학술지 Vol.14 No.2

System Complexity one of the most common cause failure of the projects, it leads to a lack of understanding about the functions of the system. Hence, the model is developed for communication and furthermore modeling help analysis, design, and understanding of the system. On the other hand, the text-based specification is useful and easy to develop but is difficult to visualize the physical composition, structure, and behaviour or data exchange of the system. Therefore, it is necessary to transform system description into a diagram which clearly depicts the behaviour of the system as well as the interaction between components. According to the International Atomic Energy Agency (IAEA) Safety Glossary, The safety system is a system important to safety, provided to ensure the safe shutdown of the reactor or the residual heat removal from the reactor core, or to limit the consequences of anticipated operational occurrences and design basis accidents. Core Protection Calculator System (CPCS) in Advanced Power Reactor 1400 (APR 1400) Nuclear Power Plant is a safety critical system. CPCS was developed using systems engineering method focusing on Departure from Nuclear Boiling Ratio (DNBR) calculation. Due to the complexity of the system, many diagrams are needed to minimize the risk of ambiguities and lack of understanding. Using Model-Based Systems Engineering (MBSE) software for modeling the DNBR algorithm were used. These diagrams then serve as the baseline of the reverse engineering process and speeding up the development process. In addition, the use of MBSE ensures that any additional information obtained from auxiliary sources can then be input into the system model, ensuring data consistency.

정보시스템 운영감리가 정보시스템 품질에 미치는 영향

주양근,김동수,이혜경,김희완 한국지식정보기술학회 2014 한국지식정보기술학회 논문지 Vol.9 No.6

Information systems have recently become an important management tool for business strategies. The Information system audit also has attracted attention because of the convergence of IT technology. The effective utilization of the system in the business following implementation of system is more important than a proper establishment of information system. People are taking advantage of the information system audit as a means of increasing the comprehensiveness of the information system. This study was performed to activate the information system operation audit and to verify that information system operation audit affects the quality of information system. We measured effects of operation audit on the quality of information system, and we analyzed how the quality of information system affects the user satisfaction. The results of the study demonstrate that the quality of information system contributes to the user satisfaction via the information system operation audit. This study verifies that the information system operation audit improves the quality of the information system but also enhances user satisfaction. Therefore, this paper suggests that information systems operations audit improves the integrity of the information system, thus the activation of operation audit leads to stable operation and user satisfaction of information system.

모델기반 시스템공학을 응용한 대형복합기술 시스템 개발

박중용,박영원,Park, Joong-Yong,Park, Young-Won 제어로봇시스템학회 2001 제어·로봇·시스템학회 논문지 Vol.7 No.8

Large-scale Multi-disciplinary Systems(LMS) such as transportation, aerospace, defense etc. are complex systems in which there are many subsystems, interfaces, functions and demanding performance requirements. Because many contractors participate in the development, it is necessary to apply methods of sharing common objectives and communicating design status effectively among all of the stakeholders. The processes and methods of systems engineering which includes system requirement analysis; functional analysis; architecting; system analysis; interface control; and system specification development provide a success-oriented disciplined approach to the project. This paper shows not only the methodology and the results of model-based systems engineering to Automated Guided Transit(AGT) system as one of LMS systems, but also propose the extension of the model-based tool to help manage a project by linking WBS (Work Breakdown Structure), work organization, and PBS (Product Breakdown Structure). In performing the model-based functional analysis, the focus was on the operation concept of an example rail system at the top-level and the propulsion/braking function, a key function of the modern automated rail system. The model-based behavior analysis approach that applies a discrete-event simulation method facilitates the system functional definition and the test and verification activities. The first application of computer-aided tool, RDD-100, in the railway industry demonstrates the capability to model product design knowledge and decisions concerning key issues such as the rationale for architecting the top-level system. The model-based product design knowledge will be essential in integrating the follow-on life-cycle phase activities. production through operation and support, over the life of the AGT system. Additionally, when a new generation train system is required, the reuse of the model-based database can increase the system design productivity and effectiveness significantly.

Le Corbusier의 주거건축에 나타나는 Dom-Ino시스템과 비례체계에 관한 연구

조성현(Cho Sung-Hyun),김철규(Kim Chul-Kyu) 한국주거학회 2004 한국주거학회 논문집 Vol.15 No.4

The purpose of this paper is to study on the architectural value in Dom-Ino system. Dom-Ino system by Le Corbusier is a structural system for effective production in terms of physical reproductivity and a modeling system from the view of formal composition. It creates planar grid with a fixed ratio, manipulates the user group, and becomes the basic construction method. Form comes out of geometrical proportion system, and grid-based plan provides regularity and order to elevation planning. Production requires standardization. Indoor space is maintained by uniformed and integrated service facilities. Dom-Ino system was a transitional step of the Modulor system which was created by Le Corbusier in 1945 and composes of and equivalent proportional system. The fact that the numerical proportion system is the one of appropriate design methods implys a progressive concept that architectural configurations are controlled by the technology of that time. And also the system is one of the object type of Corbusier's housing architecture.

공시제도의 안정적 발전을 위한 감정평가사의 전문성강화방안 - 미국 감정평가사 자격등급제의 시사점을 중심으로 -

정수연 한국부동산연구원 2009 부동산연구 Vol.19 No.2

Accurate real estate appraisals are a pre-requisite for a stable real estate assessment system, and accurate appraisals depend on the professional skill of the appraisers themselves. In the Korean real estate market, there have been long-standing issues regarding the trustworthiness of appraisals, thereby weakening one of the foundations of the real estate assessment system. Most policies seeking to address this problem have focused on the ethics of appraisers rather than on raising their level of professional expertise. Proposals for raising the professionalism of real estate appraisers generally concentrate on appraiser education. However, merely improving education cannot guarantee the stability of the real estate assessment system. The “Real Estate Assessment System for Non-Residential Real-Estate” will soon be introduced, making it more important than ever to establish a system for strengthening the professional aptitude of appraisers. This paper proposes the establishment of a body for licensing, certification, and assessing the professional competence of real estate appraisers as a suitable measure for actively improving their professional expertise. This paper cites recent examples from the U.S., which has strict licensing requirements for real estate appraisers, and considers lessons that the Korean real estate assessment system can learn from the U.S. 공시제도의 안정성은 정확한 평가가 전제되어야 가능하며, 정확한 평가는 감정평가사의 전문성에 기반한다. 오랜기간, 감정평가사의 평가에 대한 신뢰도에 대하여 논란이 있어왔고, 평가신뢰도의 저하가 공시제도의 안정성을 저해한다는 지적도 있어왔다. 그러나 평가의 정확성을 제고하기 위한 방안들은 주로 감정평가사의 윤리를 강조하는 것으로 치우쳐왔고 감정평가의 전문성을 강화하는 방안의 수립은 상대적으로 미약하였다. 기존에 제안되었던 감정평가의 전문성강화방안들은 감정평가사 교육을 강화하는 것을 주요 내용으로 하고 있다. 그러나 교육을 강화하는 것만으로는 공시제도의 안정성을 담보하기에는 부족하며, 비주거용부동산 공시제도의 도입을 앞둔 지금은 보다 적극적인 감정평가 전문성강화제도가 필요한 시점이다. 본 연구는 보다 적극적인 전문성강화방안으로서 자격등급제를 제안하고자 하였다. 이를 위하여 미국의 감정평가사 자격등급제도와 평가전문성관리메카니즘을 검토하였다. 가장 최근의 자료들을 통하여 미국의 강화된 감정평가사 자격제도를 고찰함으로써 우리나라의 감정평가사 전문성강화에 시사점을 얻고자 하였다.

구분적선형시스템을 이용한 해양 구조물의 거동분석

마호성 한국전산구조공학회 1997 한국전산구조공학회논문집 Vol.10 No.4

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. A piecewise-linear system is utilized to model the offshore mooring system. The approximated piecewise-linear restoring force is obtained to be compared with the analytically derived restoring force of a mooring system. Two systems are compared to verify the applicability of the piecewise-linear system to evaluate responses of the mooring system. Using the piecewise-linear system, the response behaviors of mooring systems are examined under various excitations. Nonlinearity of the system and effects of both system and excitation parameters are intensively examined. System responses are identified mainly by observing Poincare maps. The mooring system is found to have various types of responses such as regular harmonic, subharmonic and complex nonlinear behaviors, including chaos by utilizing a piecewise-linear system. Various values of parameters are applied to determine the effects of parameters upon system responses. Response domains are determined by establishing parametric maps.

구체축열시스템과 외기전담공조시스템이 통합 적용된 오피스건물에서 냉방에너지 소비량 특성

이윤선,이겨레,임재한 한국건축친환경설비학회 2019 한국건축친환경설비학회 논문집 Vol.13 No.2

Thermally activated building system (TABS) has been regarded as one promising technology for energy saving and green-house gas reduction due to the efficiency improvement of a cooling/heating equipment, and feasibility of combining other promising technologies such as ground source heat pumps or cooling towers. TABS can be achieved by running hot/cold water through pipes embedded in a building’s construction. Compared to conventional HVAC systems, TABS delivers higher water temperatures for cooling, and lower water temperatures for heating due to large heat exchange areas. Furthermore, water systems have less transport energy and ductwork spaces compared to existing air systems, due to high thermal capacitance of water. Because of the surface condensation problems in hot and humid weather conditions, TABS needs to be integrated with dehumidification system such as variable air volume (VAV) system or dedicated outdoor air system (DOAS). This study aims to evaluate the cooling energy consumption characteristics of thermally activated building system (TABS) integrated with DOAS in office building compared to the TABS with VAV system. In this study, the design cooling load in office building was firstly evaluated and indoor thermal environment was discussed by considering the surface condensation risk. Finally the cooling energy consumption of TABS with DOAS was compared with TABS and VAV system operation. When the total cooling energy consumption during the cooling period is compared, it is found that the integrated operation of TABS with DOAS is 24% more energy-efficient than integrated operation of TABS with VAV. Night-time electric energy consumption accounts for 34% of the total cooling energy consumption.

가변풍량제어시스템과 냉복도밀폐시스템의 적용에 의한 데이터센터의 냉방에너지 절감 효과 분석

박병윤,정용호 한국건축친환경설비학회 2013 한국건축친환경설비학회 논문집 Vol.7 No.2

In order to keep the data center server room temperature condition, cooling energy consumption has been rapidly increased as the increasing internal heat gain from the server devices. And the cooling units for server systems are fully operated to satisfy the indoor temperature condition, it results in the excessive energy consumption. There are many wastes of cooling energy which is caused by the structural problems in data center server room. For example, a leakage by the electric cable hole, mixing or recirculation of hot air from the hot aisle to the cold aisle, short circulation of the CRAC(Computer Room Air Conditioning),and others. So there are many strategies to reduce the waste of cooling energy in data center. In this study, cold aisle containment system and variable air volume system were proposed among the various strategies to reduce the energy cosumption. To verify the effectiveness of the energy saving system, test bed which is same with exist server room was set up in IDC(Internet Data Center) building and comparative experiments were carried out in actual conditions. As the result, in case of setting server room temperature 30℃, the server device inlet temperature exceeded 27℃ class 1 condition of the ASHRAE standard. But in case of setting server room temperature below 26℃, the range of inlet temperature of server system was 18~26℃ by cold aisle containment system. In case of variable air volume system and setting server room temperature 26℃, total energy saving was 19.8% to conventional cooling system. After all, variable air volume system and cold aisle containment system were proved to be the effective solution for energy saving cooling system.

도시철도 신호시스템의 절체에 따른 주파수 간섭 연구

정락교(Jeong, Rag-Gyo),김백현(Kim, Baek-Hyun),정의진(Joung, Eui-Jin) 한국산학기술학회 2010 한국산학기술학회논문지 Vol.11 No.2

철도신호시스템은 열차들의 운행간격과 열차진로를 제어하는 기능을 담당함으로써 열차를 안전하고 효율적 으로 운영하는 데 있어 핵심적인 역할을 수행한다. 철도신호시스템의 고장은 열차운행중지를 비롯하여 열차충돌이나 탈선등과 같은 치명적인 사고로 직결될 수 있기 때문에 시스템의 신뢰성과 안전성이 매우 중요하다. 현재까지 철도신 호시스템에서는 기존의 지상신호방식이 많이 사용되어 왔으나, 지상에 설치된 신호기 현시상태를 기관사가 육안으로 확인하여 열차속도를 제어함에 따른 기관사의 인적오류 등의 사고 위험이 있다. 아울러 시스템의 수명이 다 되어 시 스템절체의 필요성이 있다. 이에 따라 최근에는 컴퓨터 및 통신기술을 이용하여 열차속도제어 정보를 차량으로 송신 하여 차량에서 열차속도를 제어하는 차상신호방식이 도입 및 적용되어 효과를 나타내고 있다. 수명이 다 된 신호시스 템을 교체하기 위하여 승객을 위한 운행서비스를 하면서 새로운 방식으로 절체하는 것이 필요하다. 이에 본 논문에서 는 열차를 운영하면서 기존의 시스템과 새로운 시스템을 혼용하여 사용하면서 절체과정의 절차와 시스템 검증을 위 한 일련의 과정 중 간섭 문제에 대하여 특정한 기능을 부가하여 해결된 사례를 시험평가를 통해 검증하였다. The railway signalling system plays an essential role in the safe and efficient train operation as serving control functions of train operation intervals and train routes. The reliability and safety of the system are very important because the failure of the railway signalling system can lead to train collision or derailment as well as train operation stop. Until now, in railway signalling system the conventional wayside signal mode has been used generally. There are, however, the risk of accidents such as human mistakes caused by that the driver identifies the signal lamp status and controls train speed with the naked eye. It is also necessary to refurbish the obsolete system. Thereby, It is being effective that the onboard signal mode has been recently introduced and applied in order to transmit the speed control information to train by using the computer and communication equipment. It is necessary to switch over the system in a way while providing passengers with an operation service to replace the obsolete signal system. In this paper, we verify the cases through trial assessment which are solved by the way of adding specific functionalities in the problems of interference among the procedure of switch-over processes and a serial of processes for system verification while a train is operated in the new system in parallel to the existing system.

ERP시스템품질이 사용자만족도에 미치는 영향

여인수 ( In Soo Yeo ) 아시아.유럽미래학회 2007 유라시아연구 Vol.4 No.1

본 연구의 목적은 국내의 ERP시스템을 도입하여 사용하고 있는 기업들을 대상으로 정보시스템 품질(시스템품질, 정보품질, 서비스품질)이 정보시스템을 사용하는 사용자의 만족도에 어떠한 영향을 미치는지를 검증하고자 하였다. 이를 위하여 선행연구를 검토하였고, 이를 근거로 하여 연구모형을 제시하였다. 그리고 3가지 가설을 설정하고 모형의 타당성을 검토하기 위하여 설문을 통한 실증적인 분석을 실시하였다. 그 결과를 요약하면 다음과 같다. 첫째, ERP시스템의 시스템품질(시스템의 용이성, 유연성, 신뢰성)이 사용자의 만족도에 영향을 미치는지를 검증하였다. 검증결과 시스템의 용이성과 신뢰성이 사용자 만족도에 영향을 미치는 반면 시스템의 유연성은 영향을 미치지 않았다. 이는 ERP시스템을 이용하는 사용자들이 시스템을 쉽게 접근하여 사용하고, 인터페이스의 용이성과 산출결과나 사용용어에 대한 이해가 쉬울수록 사용자 만족도가 높다는 것을 의미하며, 시스템의 신속성과 일관성이나 데이타 손실에 대한 대책과 부정유출에 대한 대책, DB의 체계적이고 충분한 정보가 있으면 있을수록 사용자만족도가 높다는 것을 의미한다. 둘째, ERP시스템의 정보품질(정보의 정확성, 적시성, 유용성)이 사용자의 만족도에 영향을 미치는지를 검증하였다. 검증결과 정보의 정확성, 정보의 적시성과 정보의 유용성이 모두 사용자 만족도에 유의적으로 영향을 미치는 것으로 나타났다. 이는 ERP시스템을 이용하는 사용자들이 요구사항과의 일치성, 산출정보의 이해가능성등 정확성이 높으면 높을수록 사용자만족도가 높은 것으로 나타났으며, 산출정보의 적시성, 최신성, 충분성등 적시성이 높으면 높을수록 사용자만족도가 높은 것으로 나타났다. 또한 산출정보의 형태와 문제해결, 의사결정의 유용성이 높으면 높을수록 사용자만족도가 높은 것으로 나타났다. 셋째, ERP시스템의 서비스품질(서비스의 원활성, 응답성,확신성)이 사용자의 만족도에 영향을 미치는지를 검증하였다. 검증결과 원활성과 확신성은 사용자 만족도에 정(+)의 영향을 미치는 반면 응답성은 영향을 미치지 않았다. The purpose of this study is how the information system has been efficiently utilizing in ERP System in Korea and analyzing the actual status of utilizing ERP system quality, and verifying whether ERP system quality variables (system quality, information quality, service quality), have influence on the end user satisfaction of the information system. Subsequently, we first selected the quality-variable of the information system according to system quality, information quality, and service quality through careful consideration of preceding researches and texts, and then sorted the system`s accomplishments by users`` satisfaction. This study`s sample was a production company. Information was gathered through survey, and only 193 of 216 answers were used in the study. By utilizing collected sample, we established hypothesis and used empirical analysis to prove it. This study``s major results are like this: Accoding to the result of this study, ERP system quality variables (system quality, information quality, service quality) have a significantly positive relationship users` satisfaction. First, Reliability and Accessibility in the system`s quality, affects users` satisfaction. Second, Accuracy, Timeliness, Usefulness in the Information`s quality, affects users` satisfaction. Third, Assurance, Responsiveness in the Service`s quality, affects users` satisfaction.