• Nuclear Engineering and Technology
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• v.37 no.1
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• pp.109-117
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• 2005

Limiting conditions for operations (LCOs) are evaluated dynamically using the tool of system dynamics. The LCOs de-fine the allowed outage times (AOTs) and the actions to be taken if the repair cannot be completed within the AOT. System dynamics has been developed to analyze the dynamic reliability of a complicated system. System dynamics using Vensim software have been applied to LCOs assessment for an example system, the auxiliary feed water system of a reference nuclear power plant. Analysis results of both full power operation and shutdown operation have been compared for a measure of core damage frequency. The framework developed in this study has been shown to be very flexible in that it can be applied to assess LCOs quantitatively under any operational context of the TS in FSAR.

• Journal of Korean Clinical Nursing Research
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• v.14 no.2
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• pp.71-81
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• 2008

Purpose: The objective of this study was to determine the cause-effect and dynamic change mechanism among factors that affect calculation of the nursing workforce in the hemodialysis room and to establish a system dynamics model and create a strategic simulation to be used to increase efficiency in the clinical situation. Method: The system dynamics approach was adapted to build a simulation model for calculating the nursing workforce. The model was built using Vensim 5.0b DSS. Results: The results were as follows for Scenario A: The highest level of nursing service quality, patient satisfaction, and nurse satisfaction, and the lowest level of turnover intention is maintained when the ratio of patients to nurse is 3.5:1 compared to all other situations. Scenario B: At the ratio of patients to nurse 4.0:1 nursing service quality, patient satisfaction, and nurse satisfaction dropped slightly, and turnover intention also rose slightly. However with time the results showed improvement. Conclusion: In terms of economic efficiency in the hemodialysis room, the ratio of patients to nurse for the best nursing workforce should not exceed 4.0:1.

• Journal of Korean Academy of Nursing
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• v.35 no.2
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• pp.323-335
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• 2005

Purpose: The purpose of this study was to examine the problems and relevant variables for effective Organizational Socialization of new nurses, to produce a causal map, to build up a simulation model and to test its validity. Method: The basic data was collected from Sep. 2002 to July 2003. The Organizational Socialization process of new nurses was analyzed through a model simulation. The VENSIM 5.0b DSS program was used to develop the study model. Result: This Model shows interrelation of these result variables: organizational commitment, job satisfaction, job performance, intention of leaving the work setting, decision making ability, and general results of Organizational Socialization. The model's factors are characteristic of organization and individual values, task-related knowledge and skills, and emotion and communication that affects new nurses' socialization process. These elements go through processes of anticipatory socialization, encounter, change and acquisition. The Model was devised to induce effective Organizational Socialization results within 24 months of its implementation. The basic model is the most efficient and will also contribute to the development of knowledge in the body of nursing. Conclusion: This study will provide proper direction for new Nurse's Organizational Socialization. Therefore, developing an Organizational Socialization Process Model is meaningful in a sense that it could provide a framework that could create effective Organizational Socialization for new nurses.

• Journal of Navigation and Port Research
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• v.35 no.4
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• pp.343-349
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• 2011

The forecasting of container volume which is the basis of port logistics facilities expansion has a great influence on development of an port. Based on this importance, various previous studies have presented methodology on container volume forecasting. The results of many previous studies pointed out the limitations of future forecasting based on past container volume and emphasized that more various factors should be considered to compensate this. Taking notice of this point, this study forecasted future container volume by using ARIMA model, time series analysis and System Dynamics (SD) method, a dynamic analysis technique and performed the comparative review with the forecast of the Ministry of Land, Transport and Maritime affairs. Recently with rapid changes in economic and social environment, the non-linear change tendency for forecasting container traffic is presented as a new alternative to the country.

• Journal of The Korean Society of Agricultural Engineers
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• v.55 no.2
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• pp.9-20
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• 2013

Many studies have reported additional treatment is needed to use wastewater for agricultural purpose. Economic considerations should be taken into account to establish infrastructure for agricultural reuse because of a large amount of water use in irrigation and relatively low water quality requirement. The objective of this study was to conduct economic analysis of wastewater reclamation and reuse systems for agriculture. A system dynamics approach considering complexity and dynamics in the wastewater reuse systems was used for the economic analysis, which are related with social, environmental, and economic problems. Sensitivity and benefit cost analysis for wastewater reuse systems was conducted through the established economic assessment model. The result of sensitivity analysis showed that water resources development and installation cost were the most sensitive for total benefits and costs, respectively. The scenario-based test of the organized economic assessment model shows marginal cost ranges and enables decision-makers to decide reasonable cost for the wastewater reuse systems for agriculture.

• Korean System Dynamics Review
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• v.4 no.2
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• pp.95-130
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• 2003

The purpose of this study is to find what causes make public projects hold off, going beyond the planned deadline and budget. Using System Dynamics(SD) and their derivative Urban Dynamics(UD) models, it intends to analyze major feedback loops based on VENSIM and to simulate them with STELLA software, all of which are interrelated with various causes of project delay. To prevent or ameliorate project delay, first of all it advises to focus on endogenous delaying factors not exogenous ones. These factors either reinforce or balance certain loops in complex causal structure, In the case example on the Cremation Building Project in Cheongju, Residents’ participation demand make negotiation put off and delayed negotiation reinforces administrative-expediency planning in order to observe a time limit, on the other hand, once building consensus, it increase both the level of planning performance and public trust. In the meantime, the real planning process used to neglect residents opinions and manage public grievance only through compensation, he a result of simulation, visible fruit of negotiation in the initial phase seems to be not satisfactory owing to funds and time consumed, but after reaching an mutual agreement among stakeholders, planning performance is effective and strategic than administrative-expediency planning viewed in both financial and time angle. It proposes to devise specific tools schematizing project implementation. In order to upgrade the quality of project management, it recommends for planners to adopt key concepts based on SD/UD diagrams and causal loops, which would contribute to enriching Planning abbots.

• Korean System Dynamics Review
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• v.12 no.4
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• pp.125-156
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• 2011

The information service management models developed thus far have put their focuses mostly on technical dimensions of information systems (IS), finding their rationale from the goods-dominant logic (GDL) that IS as goods has value in itself. Information systems, however, is nothing more than a mechanism by which value is delivered to the users. According to the service-dominant logic (SDL), value is created and determined not at the time serve is made by the providers but at the time it is consumed by the users. The users therefore should be regarded as active value creators not as passive consumers of the value delivered by the providers. Based on the service-dominant logic, DISQM (Dynamic Information Service Quality Model) is developed. DISQM's backbone is designed in causal loop diagrams referring to and reinterpreting in systems thinking the 'Parasuraman, Zeithaml & Berry's GAP Model' and 'SERVQUAL' as an operational tool for the GAP Model, and the main IS success constructs are mapped onto the model exploiting the 'DeLone & MacLean's IS Success Model'. With VENSIM simulation software, this paper also shows how DISQM works in computer-simulation settings. After confirming DISQM's validity with the base simulation run, two scenarios are developed for the exemplary purpose and tested in terms of IS quality, service quality, and net benefits from the service for the public information service. Implications from the simulation runs are also discussed.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.30 no.4
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• pp.65-75
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• 2022

This study aims to forecast of Air Passenger Demand between South Korea and North Korea using the system dynamics analysis methodology that is based on the system thinking. System dynamics is not only a tool that makes the systematic thought to a model but also a computer program-based analysis methodology that mathematically models the system varying according to time variation. This study analyzed the causal relationship based on the interrelation among variables and structured them by considering various variables that affect aviation cooperation from the perspective of Air passenger demand forecasting. In addition, based on the causal relationship between variables, this study also completed the causal loop diagram that forms a feedback loop, constructed the stock-flow diagram of Inter-Korean model using Vensim program. In this study, Air passenger demand was using by the simulation variable value into System Dynamics. This study was difficult to reflect the various variables constituting the North Korea environment, and there is a limit to the occurrence of events in North Korea.

• Proceedings of the Korean Society of Computer Information Conference
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• 2020.01a
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• pp.117-120
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• 2020

본 논문은 인공지능 메이커 교육과 관련한 요소를 논문 네트워크 키워드 분석과 다양한 빅데이터를 종합하여 핵심용어를 선정 후 인공지능 메이커 교육을 시스템 다이내믹스의 Vensim프로그램으로 인과지도(Casual Loop Diagramming)를 구조분석(모델의 구조)하여 예측 결과를 토대로 향후 미래 상황 추출 및 정책 결정 연구에 영향을 기여한다. 연구 결과 인공지능 교육 정책은 추후 인공지능 교육과 메이커 교육을 융합한 교육 관련 산업이 증대할 것으로 예측되며 교육 경쟁력 향상과 창의적 인재 양성, OTT를 이용한 인공지능 교육 콘텐츠 향상으로 학습에 활용성이 증대하게 된다. 또한 인공지능 교육 정책은 프로그래밍 교육으로 연결되어 성장기 학습자들의 사고력과 정서 발달에 도움 되며 다양한 교재 및 기기 등장으로 인한 학습에 다양성 역시 증가할 것으로 예측된다. 학교 차원에서는 교수·연구 지원 활동이 증가하여 수업 전문성을 가진 교사가 늘어나 학교 교육의 질은 확대되고 학부모는 인공지능 교육 정책에 긍정적으로 된다. 시스템 다이내믹스는 구조가 형태를 결정짓는다는 세계관에 기초하여 피드백 루프와 동태적 형태 유형을 파악하며 다양한 가능성이 존재하게 된다. 이는 추후 다양한 연구를 통해 인공지능 교육 정책 인과지도의 확대로 연결될 수 있음을 암시하며 본 논문을 통해 인공지능 교육 연구 확산에 시발점이 되었으면 한다.

• Journal of Korean Academy of Nursing
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• v.45 no.2
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• pp.280-292
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• 2015

Purpose: In this study a system dynamics methodology was used to identify correlation and nonlinear feedback structure among factors affecting unplanned extubation (UE) of ICU patients and to construct and verify a simulation model. Methods: Factors affecting UE were identified through a theoretical background established by reviewing literature and preceding studies and referencing various statistical data. Related variables were decided through verification of content validity by an expert group. A causal loop diagram (CLD) was made based on the variables. Stock & Flow modeling using Vensim PLE Plus Version 6.0b was performed to establish a model for UE. Results: Based on the literature review and expert verification, 18 variables associated with UE were identified and CLD was prepared. From the prepared CLD, a model was developed by converting to the Stock & Flow Diagram. Results of the simulation showed that patient stress, patient in an agitated state, restraint application, patient movability, and individual intensive nursing were variables giving the greatest effect to UE probability. To verify agreement of the UE model with real situations, simulation with 5 cases was performed. Equation check and sensitivity analysis on TIME STEP were executed to validate model integrity. Conclusion: Results show that identification of a proper model enables prediction of UE probability. This prediction allows for adjustment of related factors, and provides basic data do develop nursing interventions to decrease UE.