• Korean System Dynamics Review
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• v.16 no.2
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• pp.5-32
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• 2015

Last year, a disastrous accident happened on the sea. Car ferry Se-wol which was on its way from In-cheon to Je-ju sank in the middle of the western sea. 304 passengers were drowned at the sea in the accident. There were no passengers who were waiting on board ship rescued in the accident. This study is to review the pattern of decision making in the middle of saving a life, right after Se-wol was about to sink. The starting point of this study is decision making on the rescue by rescue corps with no expert knowledge at the initial stage. When it comes to saving victims, there was no expert on rescue on the sea. Failure in rescue at Se-wol disaster lets us find a vicious circle of positive feedback loop. Experts with no experience act like well-qualified persons. Unqualified persons(leaders) have no expertise. Those who pretend to be expert occupy the important post in the hierarchy. It means we could not accumulate expertise of know-how in rescue division. That's why a vicious circle of positive feedback is formed in areas of disasters. It is necessary to train experts in Government Organizations to weaken the vicious circle of positive feedback.

• Korean System Dynamics Review
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• v.10 no.2
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• pp.53-79
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• 2009

The main purpose of this study is to find what steps are needed for a system for CO2 emissions trading to be formulated as government policy, using System Thinking approach. First, this paper analyzed Korean newspapers to consider the social issue regarding CO2 emissions trading. There were more articles related to international issues than domestic ones before 2008. This trend, however, became reversed from January 2008, which means that consideration of CO2 emissions trading has been discussed as a domestic social issue from 2008. Second, it analyzed speeches by former president Roh Moo-Hyun and current president Lee Myung-bak. In particularly, President Lee Myung-bak declared "Low Carbon and Green Growth" as a new growth engine and a Korea's vision of the future national development. Third, it examined which government agencies, including departments and committees, are pursuing policies regarding climate change, global warming, and CO2 emissions trading. Most policy has originated in the Ministry of Environment, although policy alternatives have been proposed in other agencies including the Ministry of Knowledge Economy. The study concludes that the political consideration has played a major role in the policy agenda-setting process of the CO2 emissions trading in Korea.

• The Journal of the Korea Contents Association
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• v.12 no.4
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• pp.468-475
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• 2012

Construction cost of tunnel is decided on construction area, site conditions, and construction methods. However, there is few research on developing models to estimate early construction costs. Therefore, this paper presents a model for early estimation tool for NATM tunnel using system thinking. The effect factors for tunnel construction cost were defined and the causal map is developed. Then empirical case analysis were performed to identify the cost difference due to tunnel length, excavation volume, and rock quality. The proposed model would be an alternative to estimate early construction cost of NATM tunnel.

• Korean System Dynamics Review
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• v.14 no.4
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• pp.143-163
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• 2013

This study is firstly aiming at diagnosing the present problems of evaluating the performance, especially in the field of disaster and safety management, of LGA (Local Government Authorities) in Korea. The study also deals with developing alternatives to solve a series of barrier factors revealed during the evaluation process using System Dynamics. This paper therefore presents literature review including the official documents published by the government and the performance evaluation studies of LGA. Moreover the authors analyze the current practice of the CELG (Combined Evaluation of Local Governments) as performance management, address and map a series of barrier factors in the CELG process to elaborate the CLDs (Causal-Loop Diagrams) and find solutions using system thinking with the CLDs. According to the analysis results, the core barrier factors to overcome is lack of proactive indicators/indices in the current practice of the CLEG. The authors therefore recommend to develop more proactive indicators that leads to avoid difficulties in measuring the LGA output, as well as to lessen the burden in competition for rankings and goal of the displaced.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.12
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• pp.502-512
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• 2019

To examine the problem structure of balanced regional development policy and identify the causes of the gap between the capital and non-capital areas, this study examined the causal structure in terms of the concentration and distribution of functions in the metropolitan area and non-capital area and explored the policy leverage. As a research method, the causal map was drawn using System Dynamics techniques and policy leverage was derived through an exploration of the feedback structure. In particular, the causes of the problems in balanced regional development policies were approached by system accidents rather than by single-circuit accidents, and causality analysis was performed among the variables constituting balanced regional development policies based on system accidents. In particular, it singled out 31 variables, developed 13 feedback loops, and confirmed four major policy leverages, including relocation of the capital function, local decentralization policies, consistent development, and investment practices centered on the Non­Capital Area. Subsequently, a follow-up study by computer simulation is needed by modeling the structure of the system to identify the ripple effect of the policies of the Capital Area on the Non­Capital Area.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.35 no.8
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• pp.157-168
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• 2019

Modular Construction is regarded as having enhanced safety compared to traditional construction since most of modular manufacturing process in plants. Unlike general consideration for safety in modular construction, several industrial accident data and studies have pointed out that the accident rate of modular construction is not enough less as much as the practitioners have expected. It means that there is a clear need for improvement of safety management in modular construction. To enhance safety, it is necessary to identify the type and cause of accident through accident cases in order to prevent safety accident in advance. In this consideration, this study analyzed the types and causes of accidents through root cause analysis procedure with accident cases of U.S. OSHA. The classification was carried out in the order of process type, accident type and cause of accident. By following the classification criteria in this study, the causal factor was derived and the root cause map was created. Based on the analysis results, cross-analysis was conducted and it is shown that activity characteristics of modular construction are related to safety accidents. In addition, prevention methods to reduce safety accident by major activity are presented in terms of organizational, educational and technical aspects. This study contributes that the result can be used as the basic safety management in the manufacturing and construction process of modular construction.

• Journal of The Korean Association For Science Education
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• v.39 no.5
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• pp.599-611
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• 2019

The purpose of this study is to analyze the systems thinking level of pre-service teachers using rubrics of evaluating systems thinking. For this purpose, systems thinking level model, which can be applied to education or science education, was selected through literature analysis. Eight pre-service teachers' systems thinking were investigated through the systems thinking analysis tool used in domestic research. The systems thinking presented by the pre-service teachers were transformed into the box type causal map using Sibley et al. (2007). Two researchers analyzed the systems thinking using rubrics of evaluating systems thinking. For data analysis, quantitative analysis was performed through correlation analysis using SPSS. In addition, the qualitative analysis of the box type causal map was conducted and the consistency with the quantitative analysis results was verified. The results indicated that the correlation between the 5-Likert systems thinking measurement instrument and the rubrics score was highly correlated with the Pearson product-moment of .762 (p <.05). In the hierarchical correlation of the systems thinking level, the STH model was analyzed with a very high correlation with the Pearson product-moment of .722~.791, and 4-step model was analyzed .381~.730. The qualitative analysis suggested the concept to be included in the low level of system thinking, the higher the level, the less the concept that is presented properly. In conclusion, the level of systems thinking can be derived as a result of research that there is clearly, a hierarchical part. Based on the results of this study, it is necessary to develop a systems thinking level model applicable to science education and develop and validate items that can measure the level of systems thinking.

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.799-810
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• 2009

전 세계적으로 노령화 문제가 사회적 이슈로 대두되고 있는 가운데, 노인이 느끼는 전반적인 삶의 질 (Quality of Life, QoL) 이 하락하는 문제가 사회 전반에 걸쳐 중요한 문제로 인식되고 있다. 이에 다양한 형태로 발생하고 있는 노인들의 문제를 해결하기 위하여 노인학, 사회 복지학 등의 분야에서 많은 연구가 진행되고 있다. 이 중 노인의 사회적 관계 (Social Network, SN) 를 강화, 확장하여 노인의 삶의 만족도 향상을 추구하고자 하는 연구를 찾아볼 수 있다. 이러한 관점에서 노인의 사회적 관계를 인터넷을 이용해 개선함으로써, 노인의 삶의 질을 향상시키고자 하는 것이 본 연구의 궁극적인 목표이다. 이에 본 연구의 세부적인 목적은 현재 젊은 층을 중심으로 많이 사용되고 있는 SNS 를 노인들이 사용하지 않는 이유에 대한 분석, 노인을 위한 SNS 의 핵심적인 기능적, 서비스적 요소를 파악하는데 있다. 이를 위해 현재 인터넷을 잘 활용하고 있는 60 세 이상의 노인 22 명을 대상으로 개별 인터뷰, 참가자가 사용하는 서비스 분석, FGI 의 3 가지 방식으로 데이터를 수집하였다. 이후 수집한 데이터를 이용하여 정성적 분석 방법으로 Casual Network 를 도출하였으며, 정량적 분석 방법인 Laddering 분석으로 Hierarchical Map 도출하여 비교하였다. 또한 도출된 결과가 노인들만의 특징인지를 파악하기 위하여 대학생, 직장인 각 10 명씩을 대상으로 노인을 대상으로 한 연구 방식과 동일한 방법으로 데이터를 수집, 분석 하였다. 최종적으로 본 연구는 사회감성적 선택 이론 (Socioemotional Selectivity Theory, SST)를 바탕으로 인터넷에서의 Social Network 활동도 오프라인과 유사한 특징을 가지고 있으며, 현재 친하게 지내고 있는 사람들을 중심으로 SN 을 강화시키려 하는 강화형 타입과 새로운 SN을 생성하기 위하여 노력하는 확장형 타입으로 구분할 수 있었다. 추후 이러한 특징들을 반영하여 노인들을 위한 SNS 가 지녀야 할 기능적, 시스템적 요소를 제안하고, 추후 연구 및 SNS 개발과 관련한 계획을 정리하였다.

• Korean Chemical Engineering Research
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• v.59 no.1
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• pp.68-76
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• 2021

As hazardous chemicals are releasing in process industries such as chemical & petro-chemical plants, the importance of initial responses has been always emphasized. However, little attention of quantitative analysis of the consequence by different initial responses during releasing of the chemicals has been done. The main objective of current paper is to investigate the effects of initial responses for the release accidents of hydrofluoric acid. For this, a simplified equation that can easily calculate the effect distance by varying concentrations of hydrofluoric acid was firstly deduced. In addition, a causal loops for the initial response steps using the system dynamics technique was constructed during release of 50% hydrofluoric acid. The effect distances according to different scenarios of the initial actions were also quantitatively analyzed by applying the simplified equation to the causal map. As a result, the highest reduction rate on the maximum effect distance was obtained with 'start time of action after leak detection' being about 87% while the lowest was 'arrival time of professional response team' being about 50%, as expected. It is expected that the results gained from the current study can be helpful as of basics of the initial response to the workplace, dealing with the hydrofluoric acid.

• Journal of the Korean Operations Research and Management Science Society
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• v.26 no.2
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• pp.99-109
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• 2001

In this study, we tried to build a model which can deal with the efficient and effective operation of electric power industry, especially focused on the nuclear industry. Here, SD (System Dynamics) approach is used to visualize the underlying phenomenon of the nuclear power industry. SD is a methodology for studying and managing complex feedback systems, such as one finds in business and other social systems. The spend of SD applications has grown extensively and now encompasses work in corporate planning and policy design, public management and policy, biological and medical modeling, energy and the environment. Recently, according to the report from KEPCO (Korea Electric Power Corporation), they are considering delaying a new power plant construction. It may be based upon business fluctuation downsized from Korean economic crisis in 1997 and freezing of construction funds due to unstable foreign exchange rate. At this point, we need disparately a kind of strategic model that would contribute to cope with the current business situation, energy generation, production, and resulting pollution. Specifically, this model, using SD approach, starts with the detailed drawing of influence diagram, which describes those relevant key points on nuclear power generation systems in electric power industry of Korea. These include such factors as the operation of nuclear industry and parameters related to the decision making for business policy. Based upon the above-mentioned influence diagram drawn, we developed SD simulation model to evaluate and analyze strategic management of KEPCO. Based on our analysis, we could demonstrate how simulation model can be applied to the real electric power generation in Korea.