System dynamics simulation of the thermal dynamic processes in nuclear power plants

Mohamed El-Sefy,Mohamed Ezzeldin,Wael El-Dakhakhni,Lydell Wiebe,Shinya Nagasaki 한국원자력학회 2019 Nuclear Engineering and Technology Vol.51 No.6

A nuclear power plant (NPP) is a highly complex system-of-systems as manifested through its internalsystems interdependence. The negative impact of such interdependence was demonstrated through the2011 Fukushima Daiichi nuclear disaster. As such, there is a critical need for new strategies to overcomethe limitations of current risk assessment techniques (e.g. the use of static event and fault tree schemes),particularly through simulation of the nonlinear dynamic feedback mechanisms between the differentNPP systems/components. As the first and key step towards developing an integrated NPP dynamicprobabilistic risk assessment platform that can account for such feedback mechanisms, the current studyadopts a system dynamics simulation approach to model the thermal dynamic processes in: the reactorcore; the secondary coolant system; and the pressurized water reactor. The reactor core and secondarycoolant system parameters used to develop system dynamics models are based on those of the PaloVerde Nuclear Generating Station. These three system dynamics models are subsequently validated,using results from published work, under different system perturbations including the change in reactivity,the steam valve coefficient, the primary coolant flow, and others. Moving forward, the developedsystem dynamics models can be integrated with other interacting processes within a NPP to form thebasis of a dynamic system-level (systemic) risk assessment tool.

BSC기반의 중소병원 경영성과예측 시스템다이내믹스 모델개발

정희태 ( Hee Tae Chung ),김윤신 ( Yoon Sin Kim ),곽상만 ( Sang Man Kwak ),이용균 ( Yong Kyoon Lee ) 한국시스템다이내믹스학회 2007 한국시스템다이내믹스 연구 Vol.8 No.2

Recently, balanced scorecard is widely used in the public sector as well as in the private sector. Balanced scorecard system of a particular hospital is a very useful tool in the sense that it shows various measures for the management including the traditional financial measures. However, since it does not show the impact of action items, managers have to analyze his potential decisions. On the other hand, a system dynamics model for the management of a hospital can be used to predict future management status. In this paper, a balanced scorecard system with a system dynamics model is developed for a small sized hospital, and the feasibility and applicability of the system have been tested. It turns out the combination of the balanced scorecard and system dynamics technique can be comprised each other. The balanced scorecard system can take advantage of the data forecasted by the system dynamics model including the implementation of action items taken today. On the other hand, the key performance indicators and action items from the balanced scorecard system provide guidelines the scope and direction of the system dynamics model. The additional efforts of developing a system dynamics model are well compensated by the additional colorful functionalities of the system. This paper also covers the future research areas for the combined system to be more effectively developed.

시스템 다이나믹스를 이용한 SCM 물류 흐름 분석

백종관,신현준 한국경영컨설팅학회 2007 경영컨설팅연구 Vol.7 No.4

본 연구의 목표는 시스템 다이나믹스(System Dynamics)라는 최근에 많이 사용되기 시작한 분석기법을 이용해 공급망(SCM;Supply Chain Management)의 물류 흐름을 분석하는 것이다. 새롭게 부각되고 있는 분석 툴인 시스템 다이나믹스를 통해 시스템을 분석하는 방법을 익히고 시스템 다이나믹스를 이용해 SCM에서의 RFID 영향에 대한 분석을 수행한다. 간단한 SCM 모형을 만들고 SCM에서 RFID가 얼마나 재고를 줄일 수 있으며 재고 정책에 어떤 영향을 미치는지에 대해 시스템다이나믹스를 이용해 분석하였다. 또한, 모의 실험(시뮬레이션)을 통한 분석과의 차이점을 이해하고 장단점을 분석하고 새로운 분야에 대한 적용 방법을 연구한다. 공급망에 대한 시스템 다이나믹스를 이용한 연구를 통해 공급망의 효율성을 높이고 미래를 예측하며 중요한 정책을 수립하는데 도움을 줄 수 있다. 또한 국가 공급망에 적용되어 기간산업의 물류및 정보 흐름의 일관성을 확보하고 이를 통해 공급망 관리 체계의 효율성을 향상시킴으로써 국가경제에도 긍정적인 영향을 줄 수 있을 것으로 기대한다. We suggest system dynamics for the analysis of SCM(supply chain management) logistics. System dynamics is a widely using method for analyzing complex systems. This paper provides a pity tutorial on the system dynamics method and uses the system dynamics method for analyzing a impact of RFID(Radio Frequency IDentification) on the performance of SCM. We suggest a simple SCM model for a test and analyze the effect of RFID on the inventory policy of the SCM model. And we compare the system dynamics method and the discrete event simulation, and discuss advantages/disadvantages of system dynamics

무인모니터링 시스템을 활용한 논습지에 도래하는 조류 개체군 동태 연구

남형규,김명현,권순익,어진우,송영주 한국습지학회 2018 한국습지학회지 Vol.20 No.2

본 연구는 무인모니터링 시스템을 활용하여 논에 도래하는 조류의 현황과 개체군 변동 특성을 확인하기 위해 수행되었다. 무인모니터링 시스템을 이용한 조사와 전문가에 의한 현장 조사를 비교하여 개체군 변동 특성의 유사성을 파악하였고, 무인모니터 링 시스템 조사를 통해 확인된 조류의 개체군 변동을 시공간적으로 평가하였다. 무인모니터링 시스템을 활용한 조사는 철원, 당진, 부안, 해남 4곳에서 2014년 1월 1일부터 2016년 12월 31일까지 06:00부터 20:00까지 14시간 동안 10분 단위로 촬영하였다. 전문가에 의한 현장 조사는 2016년 1월부터 12월까지 당진에서 월 1회 수행되었다. 무인모니터링 시스템을 활용하여 조사기간 동안 한 대의 무인모니터링 시스템에서 총 91,980장의 이미지를 획득하였다. 획득한 이미지 자료를 분석하여 백로류, 도요물떼새 류, 오리기러기류의 동정 및 개체군 변동을 확인하였다. 무인모니터링 시스템과 현장 조사를 비교해보면 수조류 군집 변동 패턴이 현장 조사 결과와 유사한 것을 확인 할 수 있었다. 특히 백로류의 개체군 변동의 유사성이 가장 높게 나타났다. 무인모니터링 시스템을 이용하여 지역별 백로류의 개체군 변동 특성을 확인한 결과 지역에 따라 개체군 변동 특성이 다르게 나타나는 것을 확인할 수 있었다. 또한 무인모니터링 시스템은 월 단위, 일 단위, 분 단위와 같이 다양한 시간 스케일에서 개체군 변동 특성을 확인 할 수 있는 장점을 가지는 것으로 나타났다. 무인모니터링 시스템을 이용한 장기적인 자료 축적은 논습지를 활용하는 수조류 군집의 세부적인 장기변동 특성뿐만 아니라 미래 예측에도 유용하게 이용될 것으로 기대된다. This study was conducted to identify the characteristics of bird population dynamics using unmanned monitoring system in rice paddy. We compared the similarity of population dynamics of birds between unmanned monitoring system and field survey, and evaluated the spatial and temporal patterns of population dynamics of birds using the unmanned monitoring system. The monitoring using the system was conducted from January 1, 2014 to December 31, 2016 in Cheolwon, Dangjin, Buan, and Heanam. The images from the system were obtained at 10-min intervals from 6:00 to 20:00. The field survey was conducted once a month in Dangjin from January to December 2016. Total 91,980 images were obtained from the unmanned monitoring system. We extracted the number of individuals for herons, shorebirds, and waterfowl from the images. The population dynamics of waterbirds using the unmanned monitoring system were similar to that in field survey. Especially, population dynamics of herons was more similar than other waterbirds. It was identified that the population dynamics of herons using the unmanned monitoring system was different among the Cheolwon, Dangjin, Buan, and Heanam. Furthermore, the unmanned monitoring system was available on various time scale such as month, day, and minute. It is expected that long-term data storage using the unmanned monitoring system can be used to identify in detail and forecast the population dynamics of birds in rice paddy.

북한체제 붕괴의 중장기 예측 연구

이동규(Dong Kyu Lee)(李東奎),서인석(In Seok Seo)(徐寅錫),양기근(Gi Geun Yang)(梁奇根) 위기관리 이론과 실천 2011 Crisisonomy Vol.7 No.1

북한체제 변화에 대한 연구는 체제안정론적 입장과 체제붕괴론적 입장으로 구분되는데, 본 연구에서는 체제붕괴론적 입장에서 체제의 붕괴가 언제 일어나는지, 어느 정도인지에 대한 것이다. 왜냐하면 북한의 경제난과 대외문제를 고려할 때 현재는 체제붕괴론에 더 무게가 실리기 때문이다. 이러한 맥락에서 System Dynamics를 활용한 시뮬레이션 분석은 북한체제의 붕괴시점에 대한 연구방법으로 적합한 것으로 간주된다. 특히, 관련된 중요 요인의 인과적 연쇄반응을 고려한 전체적인 시스템은 북한체제의 거시적인 변수와 미시적인 변수 모두를 고려할 수 있다는 측면에서 매우 유용하다. 본 논문에서는 지금까지 System Dynamic 분석방법을 통해서 북한붕괴시스템에 대한 체제강화의 영향에 대해 고찰해 보았다. 본 연구는 북한의 붕괴에 대해 다양한 논쟁이 이루어지고 있으나 다루지 못하였던 붕괴의 시점에 대해 다루었다는 점에서 의의가 있다. This paper is study of North Korea's System Collapse visual point that discussion has not existed. These discussion is very important when consider East Asian international situation and Korea's future circumstance. Study about North Korea system change has parted by Stability of System situation and System Collapse situation. So, In this study, it is a thing whether collapse of system occurs when, is some measure in System Collapse situation. when consider North Korea's economic difficulty and international issues, because more weight loads to System Collapse present. Simulation analysis that utilize System Dynamics in these veins counts as a thing which is suitable by method of study for North Korea Regime's System Collapse visual point. In this paper, have investigated about effect of System strengthening for North Korea Collapse system through System Dynamic analytical method.

A Review of Solid Waste Management using System Dynamics Modeling

( Kanchan Popli ),( Gamal Luckman Sudibya ),( Seungdo Kim ) 한국환경과학회 2017 한국환경과학회지 Vol.26 No.10

Solid waste management is currently a topic of concern, particularly in the protection of humans and the environment from toxic pollutants and hazardous materials. The importance of solid waste management is recognized at international, national, and community levels. Different agendas have been prioritized and assigned to improve quality of life, productivity, and health, and reduce the burden of pollution. Suitable management of solid waste requires appropriate technology that is affordable, socially accepted, and environmentally friendly. The use of a smart management system involving system dynamics can save energy, money, and labor. System dynamics is a computer-based approach that aids in predicting the behavioral patterns of variables, and correlating dependent and independent variables. The inclusion of system dynamics-based models in solid waste management has recently become more common. In this review, we used system dynamics to determine methods to disentangle solid waste management systems and analyzed different studies on solid waste management using system dynamics in different countries in detail. We also discussed the various software packages that are available for system dynamics and their usefulness for waste management. This review may help in understanding current solid waste management practices using system dynamics.

ANALYZING DYNAMIC FAULT TREES DERIVED FROM MODEL-BASED SYSTEM ARCHITECTURES

Dehlinger, Josh,Dugan, Joanne Bechta Korean Nuclear Society 2008 Nuclear Engineering and Technology Vol.40 No.5

Dependability-critical systems, such as digital instrumentation and control systems in nuclear power plants, necessitate engineering techniques and tools to provide assurances of their safety and reliability. Determining system reliability at the architectural design phase is important since it may guide design decisions and provide crucial information for trade-off analysis and estimating system cost. Despite this, reliability and system engineering remain separate disciplines and engineering processes by which the dependability analysis results may not represent the designed system. In this article we provide an overview and application of our approach to build architecture-based, dynamic system models for dependability-critical systems and then automatically generate dynamic fault trees (DFT) for comprehensive, tool-supported reliability analysis. Specifically, we use the Architectural Analysis and Design Language (AADL) to model the structural, behavioral and failure aspects of the system in a composite architecture model. From the AADL model, we seek to derive the DFT(s) and use Galileo's automated reliability analyses to estimate system reliability. This approach alleviates the dependability engineering - systems engineering knowledge expertise gap, integrates the dependability and system engineering design and development processes and enables a more formal, automated and consistent DFT construction. We illustrate this work using an example based on a dynamic digital feed-water control system for a nuclear reactor.

불확실성과 성과간의 관계에서 역동적 긴장의 매개효과

김달곤(Kim, Dal-Gon),김재열(Kim, Jae-Yeol) 대한경영학회 2007 大韓經營學會誌 Vol.20 No.5

한국 시스템다이내믹스 연구경향분석: 7년의 성과와 반성, 그리고 제안

홍영교 한국시스템다이내믹스학회 2007 한국시스템다이내믹스학회 춘계학술대회 발표논문집 Vol.2007 No.-

This paper executes positives analysis about the thesis of 100 volumes which were published for 2000-2006 years through ``Korean system Dynamics Journal``, to grope and to see the academic developments o Korean System Dynamics. The summarized analysis results are same as follows. First, korean system Dynamics researches appear that quantitative researches are much more than qualitative ones. Second, the researches that aimed to solve problem are relatively much more than theory-oriented ones. Third, System Dynamics researches in the department of social science are more abundant than that of science and engineering. Based on these results, for establishing of Korean System Dynamics identity, we will work hard to study qualitative researches, increase the research domains and elevate the academic statue of system Dynamics.

이기종 분산 환경에서 동적 재구성이 가능한 통합 관리 및 모니터링 시스템

민법기 ( Bup-ki Min ),서용진 ( Yongjin Seo ),김현수 ( Hyeon Soo Kim ),국승학 ( Seunghak Kuk ),정용환 ( Yonghwan Jung ),김점수 ( Chumsu Kim ) 한국인터넷정보학회 2012 인터넷정보학회논문지 Vol.13 No.6

본 논문에서는 이기종 분산 컴퓨팅 환경에서의 관리 대상이 되는 시스템이나 애플리케이션들의 정보 모델을 동적으로 재구성하는 통합 관리/모니터링 시스템을 개발한다. 다양한 플랫폼 위에서 동작하는 하위 시스템들이 추가, 제거, 수정되는 상황에서 분산시스템을 효과적으로 관리하기 위해서는 분산 시스템의 형상과 통합 관리/모니터링 시스템의 정보가 일치해야 한다. 이에 시스템의 형상이 변화되었을 때, 시스템의 변경된 형상과 통합 관리/모니터링 시스템의 정보가 동기화되어야 하며, 동기화가 수행되는 동안 시스템은 정지 없이 모니터링 정보를 사용자에게 제공할 수 있는 가용성이 보장되어야 한다. 본 논문에서는 관리 대상인 하위 시스템에서 하드웨어나 소프트웨어의 형상의 변경이 있을 때 변경 내용을 통합 관리/모니터링 시스템에 통보하고, 통보된 정보를 바탕으로 관리 대상인 하드웨어 및 소프트웨어의 정보들을 동적으로 재구성 하는 방법을 제안한다. 이를 통해 어떤 이기종 분산 시스템도 통합 관리/모니터링 시스템에 반영하여 신뢰성 있는 통합 관리를 수행할 수 있을 것으로 기대된다. In this paper, we develop an integrated management/monitoring system that supports to dynamically reconfigure information models for systems or applications managed by heterogeneous distributed systems. When the subsystems on diverse platforms are added, removed, or modified, the altered configurations should conform to the configuration information of the integrated management/monitoring system. Further, upon the system configurations being changed, the altered system configurations should be synchronized with the information on the integrated management/monitoring system. Moreover, availability should be assured during synchronization to the extent that users can access the monitoring information with no system halting. This paper focuses on notifying the integrated management/monitoring system of any changes in hardware/software configurations on any subsystems under its management, and on dynamically re-configuring the information about hardware and software being managed based on the information notified. Finally, we expect that this research will be contributory to carrying out reliable integrated management by reflecting the information on any heterogeneous distributed systems in the integrated management/monitoring system.