• 대한교통학회:학술대회논문집
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• 대한교통학회 1995년도 제27회 학술발표회
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• pp.84-98
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• 1995

Network-based model were developed to predict short term future traffic volume based on current traffic, historical average, and upstream traffic. It is presumed that upstream traffic volume can be used to predict the downstream traffic in a specific time period. Three models were developed for traffic flow prediction; a combination of historical average and upstream traffic, a combination of current traffic and upstream traffic, and a combination of all three variables. The three models were evaluated using regression analysis. The third model is found to provide the best prediction for the analyzed data. In order to balance the variables appropriately according to the present traffic condition, a heuristic adaptive weighting system is devised based on the relationships between the beginning period of prediction and the previous periods. The developed models were applied to 15-minute freeway data obtained by regular induction loop detectors. The prediction models were shown to be capable of producing reliable and accurate forecasts under congested traffic condition. The prediction systems perform better in the 15-minute range than in the ranges of 30-to 45-minute. It is also found that the combined models usually produce more consistent forecasts than the historical average.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2005년도 동계학술발표대회 논문집
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• pp.281-287
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• 2005

This study investigates the pressure drop and heat transfer characteristics of heat exchanger according to the combination of fin configuration and fin pitch of each row by the similitude experiments with the finned-tube geometry scaled as large as four times Finned-tube heat exchanger has 2 rows, and fin geometry consists of two cases, louver-louver and louver-slit. Fin pitch is varied with three types in each case, 6-6 mm, 8-8 mm and 8-6 mm. Results show that total heat transfer can be occurred evenly at each row by varying the fin pitch of 1st row and 2nd row. Heat transfer rate and pressure drop characteristics change according to the combination for fin geometry and fin pitch.

• Tribology and Lubricants
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• 제22권2호
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• pp.66-72
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• 2006

Leakage reduction through annular type labyrinth seals of steam turbine is necessary for enhancing their efficiency and the precise prediction method of seal leakage is needed. In this study, numerical analysis for leakage prediction of the combination-type-staggered-labyrinth seal has been carried out using FLUENT 6 which is commercial CFD (Computational Fluid Dynamics) code based on FVM (Finite Volume Method) and SIMPLE algorism. The present CFD results are verified with the theoretical analysis based on Bulk-flow concept which has been mainly used in predicting seal leakage. Comparing with the result of Bulk-flow model analysis, the leakage result of CFD analysis shows good agreement within 7.1% error.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 B
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• pp.771-772
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• 2006

Recently, Interior Permanent Magnet Synchronous Motor(IPMSM) is widely used in the industry applications such as power train for hybrid vehicles and compressor motors of air-conditioner due to its high power density and wide speed range. In designing motors, pole slot combination should be chosen properly according to the use of the motor and driving method in the initial design stage, accordingly there have been many researches about pole slot combination. As a part of the studies, this paper presents a comparison of characteristics of concentrated winding IPMSM, such as back-emf, Total Harmonic Distortion(THD) and core losses for each pole slot combination. By comparing the characteristics of each model, this paper can be a guide or reference in determining pole slot combination in the initial design stage.

• Journal of Information Processing Systems
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• 제15권6호
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• pp.1489-1502
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• 2019

This work introduces a novel unweighted combination method (UCSS) for business failure perdition (BFP). With considering features of BFP in the age of big data, UCSS integrates the quantitative and qualitative analysis by utilizing soft set theory (SS). We adopt the conventional expert system (ES) as the basic qualitative classifier, the logistic regression model (LR) and the support vector machine (SVM) as basic quantitative classifiers. Unlike other traditional combination methods, we employ soft set theory to integrate the results of each basic classifier without weighting. In this way, UCSS inherits the advantages of ES, LR, SVM, and SS. To verify the performance of UCSS, it is applied to real datasets. We adopt ES, LR, SVM, combination models utilizing the equal weight approach (CMEW), neural network algorithm (CMNN), rough set and D-S evidence theory (CMRD), and the receiver operating characteristic curve (ROC) and SS (CFBSS) as benchmarks. The superior performance of UCSS has been verified by the empirical experiments.

• 디자인학연구
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• 제16권2호
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• pp.57-66
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• 2003

정보처리기술을 활용한 칼라 감성 시뮬레이션이 상품개발 지원시스템으로서 개발, 활용되기 시작하고 있다. 칼라배색 등을 결정하기 위한 시뮬레이션 시스템에서는 감성평가실험을 통해 구축한 데이터베이스를 이용하여 배색후보들을 제시하는 것이 일반적이다. 그러나 이들 방법에서는 시스템 이용자(디자이너나 사용자)의 취향이나 선호도, 혹은 이용자 상호간의 감성적차이(gap) 등을 고려하여 최종 배색후보를 결정해 가는 과정까지는 지원하고 있지 않다. 이와 같은 점에 주목하여 본 연구에서는 시스템이 초기 배색 후보군을 생성한 다음, 디자이너가 다양한 배색 시뮬레이션을 함으로써 목적으로 하는 최종 배색후보를 결정해 가는 과정을 지원하는 칼라배색시뮬레이터를 제안하였다. 이 시뮬레이터는 디자이너가 시스템과의 커뮤니케이션에 의해 디자이너의 취향과 선호도에 맞는 배색을 탐색할 뿐만 아니라 검색자가 최적이라고 판단하기 용이한 환경을 제공함으로써 시스템이 검색자의 판단을 지원하는 디자인지원시스템의 성격을 가진다. 칼라 배색시뮬레이터는 디자이너의 사고과정을 모델화 한 이중매핑 모델(Dual Mapping Model)에 기초로 두고 구성되었으며, 칼라컨셉설정$\longrightarrow$배색후보군 생성$\longrightarrow$배색 시뮬레이션$\longrightarrow$최종배색 후보의 순위결정 등의 4단계에 걸친 조작으로 칼라 디자인과정을 지원하게 된다.

• Structural Engineering and Mechanics
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• 제62권4호
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• pp.507-517
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• 2017

Due to the discontinuous nature of uncertainty quantification in conventional evidence theory(ET), the computational cost of reliability analysis based on ET model is very high. A novel ET model based on fuzzy distribution and the corresponding combination rule to synthesize the judgments of experts are put forward in this paper. The intersection and union of membership functions are defined as belief and plausible membership function respectively, and the Murfhy's average combination rule is adopted to combine the basic probability assignment for focal elements. Then the combined membership functions are transformed to the equivalent probability density function by a normalizing factor. Finally, a reliability analysis procedure for structures with the mixture of epistemic and aleatory uncertainties is presented, in which the equivalent normalization method is adopted to solve the upper and lower bound of reliability. The effectiveness of the procedure is demonstrated by a numerical example and an engineering example. The results also show that the reliability interval calculated by the suggested method is almost identical to that solved by conventional method. Moreover, the results indicate that the computational cost of the suggested procedure is much less than that of conventional method. The suggested ET model provides a new way to flexibly represent epistemic uncertainty, and provides an efficiency method to estimate the reliability of structures with the mixture of epistemic and aleatory uncertainties.

• 한국건설관리학회논문집
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• 제8권4호
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• pp.194-202
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• 2007

건설공사의 초기 단계인 토공사의 경우 현장 토공계획에 부합하는 다양한 건설장비를 활용하여 수행된다. 이 경우 짧은 시간에 다종의 건설기계장비가 투입되며 많든 공사비가 소요되는 만큼 어느 공종보다도 토공관리자의 합리적인 계획 수립이 요구된다. 그러나 대부분의 경우 경험과 직관을 바탕으로 토공장비계획이 수립되어 공정관리 및 원가절감 차원에서 적절한지 검증이 어려우며, 계획수립에 요구되는 고려조건이 변경될 때마다 시간과 인력을 투입해야하는 실정이다. 이에 본 연구에서는 시스템 다이내믹스 기법을 활용하여 기계화 토공장비의 굴삭과 적재 및 운반단계를 대상으로 토공장비의 적정 조합모형을 구축한다. 연구의 결과로 도출되는 토공장비의 적정 조합모형은 토공계획을 담당하는 관리자가 토공장비계획을 함에 있어 짧은 시간에 합리적인 판단을 하도록 지원해줄 것으로 기대된다.

• 전자공학회논문지
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• 제53권2호
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• pp.62-69
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• 2016

본 논문에서는 대화력전의 목표달성에 대한 평가척도를 선정하고 평가척도의 최적값을 만족하는 청군의 타격자원의 합리적인 조합과 목표달성시간의 회귀식을 도출하고자 하였다. 또한 현실세계에서 회귀식을 도출하는 일련의 과정을 연구방법론적 관점에서 제시하고자 하였다. 이를 위해 현재 북한과 대한민국이 보유하고 있는 무기체계들의 정보를 이용하여 대화력전을 단순화한 시뮬레이션을 만들어 목표달성시간을 도출하였다. 시뮬레이션에서는 대화력전을 탐지, 결정, 타격의 세 단계로 나누었다. 탐지에는 난수를 활용한 확률을 적용했고 결정과 타격은 고정된 상수를 적용시켰다. 고정된 적에 대해서 목표달성시간을 도출하였으며 목표달성시간이 최단시간으로 나오는 것이 시뮬레이션의 최적값이라고 판단했다. 시뮬레이션의 목표달성시간을 바탕으로 미니탭의 반응표면분석법을 이용하여 고정된 홍군에 대한 청군 무기체계의 최적조합 및 회귀식을 도출하였다. 도출된 회귀식은 2-표본 t검정을 이용하여 검증하였다.

• Biomolecules & Therapeutics
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• 제2권1호
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• pp.23-27
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• 1994

Wound healing and antibacterial effects of solcoseryl-micronomicin combination gel on an open wound were studied in mice. A simple model was designed for assessing the effects. Using the model, we compared the efficacy of a combined topical gel of solcoseryl and micronomicin with those gels of solcoseryl or micronomicin alone. From the results of our experiment, the wound healing effect of open wounds by treatment with the combination gel was significantly enhanced when compared with those by treatment with solcoseryl gel or micronomicin gel alone. And the antibacterial effect of the combination gel was higher than those of solcoseryl gel or micronomicin gel alone.