• Proceedings of the Korea Society for Simulation Conference
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• 2000.04a
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• pp.7-11
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• 2000

본 연구에서는 다품종 수주생산형 장치산업에서 대 Lot의 분할생산, Lot간 setup을 포함하는 Loss time의 감축, 납기현실화, 선별적 수주정책 등 다양한 수주 및 생산정책을 평가하는 확정적 시뮬레이션 모형을 개발하였다. 평가기준으로는 수주일부터 생산일까지의 대기일과 납기준수율을 사용하였다. 사례연구로 A화학공장의 1999년도 수주데이타를 입력자료로 사용하여 모형의 타당성을 보이고 납기단축 및 납기준수율 제고를 위한 효과적인 대안을 도출하였다.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.7 no.1
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• pp.10-21
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• 2008

User travel behavior is based on the existence of complete traffic information in deterministic user optimal principle by Wardrop(1952). According to deterministic user optimal principle, users choose the optimal route from origin to destination and they change their routes arbitrarily in order to minimize travel cost. In this principle, users only consider travel time as a factor to take their routes. However, user behavior is not determined by only travel time in actuality. Namely, the models that reflect only travel time as a route choice factor could give irrational travel behavior results. Therefore, the model is necessary that considers various factors including travel time, transportation networks structure and traffic information. In this research, more realistic deterministic optimal traffic assignment model is proposed in the way of route recognizance behavior. This model assumes that when users decide their routes, they consider many factors such as travel time, road condition and traffic information. In addition, route recognizance attributes is reflected in this suggested model by forward searching method and backward searching method with numerical formulas and algorithms.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.18 no.4
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• pp.337-347
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• 2009

Generally, finite element models used in structural analysis have some uncertainties of the geometric dimensions, applied loads and boundary conditions, as well as in material properties due to the manufacturability of aluminum intensive body. Therefore, it is very important to refine or update a finite element model by correlating it with dynamic and static tests. The structural optimization problems of automotive body are considered for mechanical structures with initial stiffness due to preloading and in operation condition or manufacturing. As the mean compliance and deflection under preloading are chosen as the objective function and constraints, their sensitivities must be derived. The optimization problem is iteratively solved by a sequential convex approximation method in the commercial software. The design variables are corrected by the strain energy scale factor in the element levels. This paper presents an updated method based on the sensitivities of structural responses and the residual error vectors between experimental and simulation models.

• Journal of Korea Water Resources Association
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• v.35 no.3
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• pp.331-344
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• 2002

This study is aimed at the development of a deterministic runoff model which can be used for flood runoff. The model is formulated by the watershed runoff model. Based on the assumptions that runoff system is nonlinear, the proposed watershed runoff model is the conceptual model. In the model structure, the conceptual model divides the runoff system into a surface structure and a subsurface structure corresponding to the surface flow, and inter flow and ground water flow respectively. The lag time effect of surface can be represented by the sub-tank of surface structure in the conceptual model. The parameter calibration of inter flow and ground water flow in the subsurface structure of the conceptual model is performed by separating the components with numeric filter The runoff coefficient($\alpha$$_2$) is expressed as the function of antecedent precipitation index(API). The parameters with the surface flow can be calibrated with the runoff coefficient($\alpha$$_1$ and $\alpha$/$_{11}$) in the conceptual model. In the conceptual model, an algorithm is developed to calibrate the parameters automatically based on efficiency criteria. The comparative study shows that simulated value from the conceptual model well agreed to observed value.

• KDI Journal of Economic Policy
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• v.16 no.4
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• pp.27-45
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• 1994

경기변동(景氣變動)에 대한 중요한 판단자료인 산업생산지수(産業生産指數)는 음력에 따르는 구정, 추석 등의 기간 및 시점변동으로 계절적 요인이 불규칙하게 나타나게 되고, 이로 인하여 지수(指數)의 분석에 혼란이 야기되고 있다. 산업생산지수(産業生産指數)의 계절변동(季節變動)은 일차적으로 근로일수(勤勞日數)에 그 원인이 있는 것으로 판단된다. 본고(本稿)에서는 통상의 계절조정방법 대신에 근로일수를 고려하여 1일당 생산을 기준으로 산업생산을 분석하였다. 근로일수(勤勞日數)는 확정적(確定的)(deterministic)인 성격을 가지고 있어 계절성(季節性)의 변동에 대한 예측(豫測)이 가능할 뿐 아니라, 1일당 생산을 고려할 경우 각 관측치의 시간적 길이를 동일하게 함으로써 생산과 재고의 관계를 설정하는 것이 용이해진다. 생산(生産)과 재고변화(在庫變化)만을 이용한 간단한 오차수정모형(error correction model)을 설정하여 생산의 표본외구간(標本外區間) 예측(豫測)(out of sample forecasting)을 수행한 결과, 근로일수(勤勞日數)로 조정하였을 경우 예측력이 현저히 개선됨을 확인할 수 있었다.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.1038-1041
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• 2009

현재 수자원 분야에서는 기후변화와 이에 대비한 안정적인 물공급을 위한 수자원 계획이 요구되는 시점이다. 따라서, 신뢰성있는 장기간의 유량자료를 확보하기 위하여 추계학적 기상모의자료를 이용하여 유역의 장기간에 걸친 공간적인 유량자료를 생성하고자 하였다. 본 연구에서는 한강유역에 대하여 추계학적인 방법을 이용하여 장기간의 기상자료(강수량, 최대/최소 온도, 일사량, 상대습도, 풍속)를 생성하였다. 기상모의생성을 위하여 WXGEN(Sharply와 Williams, 1990)을 이용하였다. 기상모의 발생순서는 우선 강수량을 독립적으로 모의생성하였다. 이후 최대/최소 온도, 일사량, 상대습도는 약한 상관성을 가진다는 가정으로 모의생성한 후, 해당일의 강수유무를 기준으로 값을 조정하였다. 마지막으로 풍속은 독립적으로 모의생성하였다. 모의생성된 장기간의 기상자료를 장기유출모형인 SWAT-K의 입력자료로 활용하여 한강유역에 대하여 장기간의 유량자료를 모의 분석하였다. 이러한 연구는 추계학적 방법과 확정론적 방법의 연계적용으로 수자원 설계 및 계획에 적극 활용될 수 있을 것이다.

• Journal of Korean Society of Transportation
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• v.22 no.7 s.78
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• pp.155-159
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• 2004

Recently, there are many trials about Artificial neural networks : ANNs structure and studying method of researches for forecasting traffic volume. ANNs have a powerful capabilities of recognizing pattern with a flexible non-linear model. However, ANNs have some overfitting problems in dealing with a lot of parameters because of its non-linear problems. This research deals with the application of a variety of model selection criterion for cancellation of the overfitting problems. Especially, this aims at analyzing which the selecting model cancels the overfitting problems and guarantees the transferability from time measure. Results in this study are as follow. First, the model which is selecting in sample does not guarantees the best capabilities of out-of-sample. So to speak, the best model in sample is no relationship with the capabilities of out-of-sample like many existing researches. Second, in stability of model selecting criterion, AIC3, AICC, BIC are available but AIC4 has a large variation comparing with the best model. In time-series analysis and forecasting, we need more quantitable data analysis and another time-series analysis because uncertainty of a model can have an effect on correlation between in-sample and out-of-sample.

• Journal of the Korean Society for Library and Information Science
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• v.45 no.2
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• pp.309-324
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• 2011

The purpose of this study is to develop evaluation indicators for academic libraries in Korea. The evaluation model developed in this research consists of three elements:(1) Confirmation of evaluation methods, procedures and criteria,(2) Development of qualitative and quantitative evaluation indicators, and(3) Assessment of the applicability and feasibility of those indicators. Evaluation indicators were developed to measure a basic state, a common use of library resources, specialized services, and user satisfaction for academic libraries. To test the feasibility and applicability of those evaluation indicators, a pilot assessment of academic libraries was conducted in 2010.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.1
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• pp.87-98
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• 2012

The Ministry of Education, Science and Technology has been implementing the government's recognition project regarding the program accrediting organizations in Higher Education. This research is to establish an evaluation model for the government's recognition process of the program accrediting organizations, and develop the evaluation categories, items and indices for the model. The research has set the concept for the government's recognition regarding the program accrediting organizations and designed an evaluation model for such organizations. The evaluation model embraces a preliminary evaluation process, assessing an eligibility of the accrediting organizations for the higher education based on the formalities set forth for the government recognition organization accrediting process. It also includes the main evaluation process, which assess the eligibility based on the evaluation standards stipulated in the associated legislation and regulations. In addition, through in-depth verification processes by experts, this research finalized 2 evaluation domains, 5 evaluation categories, 24 evaluation items and 33 evaluation indices.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.8
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• pp.2899-2905
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• 2010

To be applicable under electronic health record system in order to ensure semantic interoperability of clinical information, the development principle for clinical information model to reflect objective and function is required. The aim of this study is to develop the development principles for clinical information model and evaluate the Clinical Contents Model. In order to develop the principle, from November 2008 to March 2009, the surveys about 1) definition, 2) function and 3) quality criteria were done, and 4) the components of advanced model were analyzed. The study was processed in 3 levels. Firstly in the development level, key words and key words-paragraph were driven from the references, and the principles were drawn based on the clinical or functional importance and frequency. In the application level, the 3 experts of clinical information model assessed 30 Clinical Contents Models by applying it. In the feedback level, the Clinical Contents Model in which errors were found was modified. As the results, 18 development principles were derived with 3 categories which were structure, process and contents. The Clinical Contents Models were assessed with the principles, and the 17 models were found that they did not follow it. During the feedback process, the necessity of the advanced education of the principle and the establishment of the regular quality improvement strategy to use it is raised. The proposed development principle supports the consistent model-development between clinical information model developers, and could be used as evaluation criteria.