• 한국국방경영분석학회지
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• 제25권1호
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• pp.37-54
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• 1999

In this paper, we proposed a modeling method of continuous combat simulation by using VENSIM. VENSIM is a CASE tool for developing continuous simulation. It provides a simple and flexible way of building simulation models from causal loop or influence diagram. As a case model, we developed "a prototype model of battle"incorporating infantry, artillery, air defense weapon, aircraft, and guerrilla engagement.ngagement.

• Steel and Composite Structures
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• 제4권4호
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• pp.281-301
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• 2004

The paper begins by presenting a unified variational approach to the lateral-torsional buckling (LTB) analysis of doubly symmetric prismatic and tapered thin-walled beams with open cross-sections, which accounts for the influence of the pre-buckling deflections. This approach (i) extends the kinematical assumptions usually adopted for prismatic beams, (ii) consistently uses shell membrane theory in general coordinates and (iii) adopts Trefftz's criterion to perform the bifurcation analysis. The proposed formulation is then applied to investigate the influence of the pre-buckling deflections on the LTB behaviour of prismatic and web-tapered I-section simply supported beams and cantilevers. After establishing an interesting analytical result, valid for prismatic members with shear centre loading, several elastic critical moments/loads are presented, discussed and, when possible, also compared with values reported in the literature. These numerical results, which are obtained by means of the Rayleigh-Ritz method, (i) highlight the qualitative differences existing between the LTB behaviours of simply supported beams and cantilevers and (ii) illustrate how the influence of the pre-buckling deflections on LTB is affected by a number of factors, namely ($ii_1$) the minor-to-major inertia ratio, ($ii_2$) the beam length, ($ii_3$) the location of the load point of application and ($ii_4$) the bending moment diagram shape.

• 산업경영시스템학회지
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• 제30권3호
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• pp.37-43
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• 2007

We use influence diagrams to describe event trees used in safety analyses of low-probability high-risk incidents. This paper shows how the branch parameters used in the event tree models can be updated by a bayesian method based on the observed counts of certain well-defined subsets of accident sequences. We focus on the analysis of the shared branch parameters, which may frequently often in the real accident initiation and propagation to more severe accident. We also suggest the way to utilize different levels of accident data to forecast low-probability high-risk accidents.

• 대한안전경영과학회지
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• 제12권3호
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• pp.1-11
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• 2010

Establishing a framework, to explain the path to safety accidents considering major safety management factors such as physical conditions including on-site activities and workplace, as well as human factors as to labor, supervisors, or managers, would be effective as the basis to control project's risks by preventing disasters. Therefore, this study aimed to clarify the mechanism in safety management and disaster occurrence. In order to accomplish the purpose, it identified and classified the factors related to accidents, reviewed the causal relationships among them, and suggested the influence diagram. The results of this research are expected to contribute to reinforcing the preventive management, and facilitating the development of integrated site control system based on safety risks.

• 한국정보기술학회 영문논문지
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• 제9권1호
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• pp.67-76
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• 2019

Recently, with the advent of the software-based society, many organizations have been providing software developing education, such as coding, to Computer Science majors and non-Computer Science majors. When implementing a program, teachers can let students draw a variety of diagrams, such as flowcharts, UML diagrams, and ERD diagrams ahead. As the importance of computational thinking is increasingly emphasized, abstracting algorithms into diagrams is considered an important educational element. In this paper, we examined the visual literacy and abstract/concrete way of thinking of novice programmers in order to analyze factors affecting the abstraction process of drawing diagrams, and how they influence students' ability to understand diagrams and ability to draw. If we understand what factors influence the abstraction process in this study, we can suggest educational alternatives for future strategies in which teachers will teach students.

• 한국시스템다이내믹스연구
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• 제4권2호
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• pp.153-171
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• 2003

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 span 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 desperately 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 (actors 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 KBPCO. Based on our analysis, we could demonstrate how simulation model can be applied to the real electric power generation in Korea.

• 한국경영과학회지
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• 제26권2호
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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.

• 자원리싸이클링
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• 제16권2호
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• pp.12-16
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• 2007

Chalcopyrite 를 대상으로 광미 중에 함유된 Sulfide 물질의 부유선별에 의한 분리회수 과정에서 산화가 부유성에 미치는 영향을 고찰하였다. Zisman Plot에 의해 도출된 Chalcopyrite 의 임계계면장력은 약 15.5 dyne/cm인 것으로 파악되었으며 포수제의 농도가 증가함에 따라 그 값은 감소하여 Chalcopyrite의 부유성이 상승하는 것으로 관찰되었다. 초기 산화에 의한 Chalcopyrite의 부유성 상승은 $S_2^{2-}$의 $S^o$로의 전환에 기인하는 것으로 판단되었으며 형성된 $S^o$가 $S_4^{2-}$ 및 $S_2O_3^{2-}$로 재전환됨에 따라 Chalcopyrite의 부유성은 다시 감소하는 것으로 사료되었다. 산화된 Chalcopyrite의 환원 시 부유성은 상승하는 것으로 나타났으며 산화/환원 과정에서의 임계계면장력의 변화 양상은 원자간 Bond Energy의 변화에 의거한 Energy Diagram으로 해석되었다.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2002년도 추계공동학술대회논문집
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• pp.139-145
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• 2002

수로에서의 선박통항으로 인해 주변환경 렌 구조물에 미치는 영향을 평가하기 위하여 선박의 추진기로 인한 흐름을 다루었다. 제한수로에서의 수치모델은 Shield's diagram과 추진기의 운동량 이론을 사용하여 개발하였다. 프로펠러에 의한 추진기방정식은 분사를 정의하는 가장 정확한 수단으로 분사계수와 분사유속을 기초로 하여 수립하였다 추진기분사에 대해 접근한 방법은 적용 선박의 출력에 기초하였으며, 추진기 분사방정식의 주요함수에는 추진력, 프로펠러 직경, 그리고 선박의 속도를 도입하였다. 또한, 수로의 수심과 선박의 홀수도 초기이동한계입경의 계산에 필요하다. 추진기로부터 분사된 유속의 분포는 Gaussian 정규분포함수로 나타내었다 저면마찰속도와 진단응력은 Sternberg 공식으로부터 유도되었으며, 아울러 선박 추진기로 인해 수로저면에서 표사이동에 현저한 영향을 미치는 경우를 사례연구를 통해서 나타내었다.

• 디지털산업정보학회논문지
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• 제13권4호
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• pp.231-245
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• 2017

The purpose of this study is to analyze the trend line through scatter diagram analysis on correlation between SNS addiction tendencies and learning attitudes, figure out the knee point influencing learning attitudes negatively in detail, and examine influence among subareas. To address the goal, study questions are formulated as follows. First, this author did screening on the data of variables measured and analyzed descriptive statistics. Second, this researcher produced the trend line by drawing a scatter diagram in order to analyze correlation between SNS addiction tendencies, withdrawal symptoms, excessive communication, and excessive time wasting, and learning attitudes exploratorily. Third, to explore correlation between self-evaluation, learning participation, and developmental attitudes, the subfactors of learning attitudes related to SNS addiction tendencies, this author drew a scatter diagram and analyzed the threshold of positive and negative correlation. To verify the study questions, the SNS addiction tendency scale and learning attitude scale were applied to 301 university students in Chungcheong area. According to the study results, first, their learning attitudes are influenced by SNS addiction tendencies, excessive communication and excessive time wasting, and they are not influenced by withdrawal symptoms that much. Second, excessive communication, a factor of SNS addiction tendencies, and self-evaluation and developmental attitudes, factors of learning attitudes, show positive correlation to some extent and indicate negative correlation after the threshold. However, excessive communication and learning participation are found to show no correlation. Third, according to the results of examining correlation with learning attitudes by dividing them into excessive communication and excessive time wasting groups with the knee point of 1.40, as the symptom of excessive communication is found more, it influences self-evaluation, learning participation, developmental attitudes, and learning attitudes more negatively in general. The result of this study is expected to provide foundational material necessary to develop educational programs to prevent undergraduates' excessive SNS use and SNS addiction which can be used in the scenes of counseling or education.