• Title/Summary/Keyword: Choice Modeling

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The Application of CFD for Ship Design (선박설계를 위한 계산유체역학의 활용)

  • Kim Wu-Joan;Van Suak-Ho
    • Journal of computational fluids engineering
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    • v.8 no.2
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    • pp.42-48
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    • 2003
  • The issues associated with the application of CFD for ship design are addressed. Doubtlessly at the moment, CFD tools are very useful in evaluating hull forms prior to traditional towing tank tests. However, time-consuming pre-processing is an obstacle in the daily application of CFD tools to improve hull forms. The accuracy of computational modeling without sacrificing the usability of CFD system is also to be assessed. The wave generation is still predicted by using potential panel methods, while velocity profiles entering into propeller plane is solved using turbulent flow solvers. The choice of turbulence model is a key to predict nominal wake distribution within acceptable accuracy. The experimental data for CFD validation are invaluable to improve physical and numerical modeling. Other applications of CFD for ship design than hull form improvement are also given. It is certain that CFD can be a cost-effective tool for the design of new and better ships.

Evaluating Modified IKONOS RPC Using Pseudo GCP Data Set and Sequential Solution

  • Bang, Ki-In;Jeong, Soo;Kim, Kyung-Ok
    • Proceedings of the KSRS Conference
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    • 2002.10a
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    • pp.82-87
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    • 2002
  • RFM is the sensor model of IKONOS imagery for end-users. IKONOS imagery vendors provide RPC (Rational Polynomial Coefficients), Ration Function Model coefficients for IKONOS, for end-users with imagery. So it is possible that end-users obtain geospatial information in their IKONOS imagery without additional any effort. But there are requirements still fur rigorous 3D positions on RPC user. Provided RPC can not satisfy user and company to generate precision 3D terrain model. In IKONOS imagery, physical sensor modeling is difficult because IKONOS vendors do not provide satellite ephemeris data and abstract sensor modeling requires many GCP well distributed in the whole image as well as other satellite imagery. Therefore RPC modification is better choice. If a few GCP are available, RPC can be modified by method which is introduced in this paper. Study on evaluation modified RPC in IKONOS reports reasonable result. Pseudo GCP generated with vendor's RPC and additional GCP make it possible through sequential solution.

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The Experiment of Architectural Design Education by means of BIM (BIM을 이용한 건축디자인 교육의 실험연구)

  • Kim, Yong-Il;Yang, Kwan-Mok
    • Journal of the Korean Institute of Educational Facilities
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    • v.19 no.5
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    • pp.37-43
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    • 2012
  • Results of experiments conducted in university-based design studio suggests that Building information Modeling invites the adoption of a dramatically different design process, traditional design process and BIM-aided design process. Experiment method is used the actual experiment by students. In contrast to traditional design process rooted in successive refinement of abstractions and dependence on tacit knowledge, the studio BIM-aided design process depends on a complete and comprehensive date base and alterative solutions by complete analysis for helping choice of finial result. BIM viewed as provocateur of design education provides great potential for the critical analysis of how architectural design is taught. The results reflect new ways of teaching and addressing BIM methods and process in the design studio project.

Modeling of Policy Making for Big Data (빅데이터를 위한 정책결정 설계)

  • Lee, Sangwon;Park, Sungbum;Kim, Sunghyun;Chae, Seong Wook
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2015.01a
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    • pp.281-282
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    • 2015
  • Data, by itself, will not reveal the optimal policy choice. Nor will data alone tell us what problems to focus on or how to direct resources. It should be recognized upfront that data-driven policy making cannot provide all the answers to the challenges of good governance. Policy decisions always depend on a combination of facts, analysis, judgment, and values. In this paper, we research on factors to design an organizational policy making for Big Data.

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The Application of CED for Ship Design (선박설계를 위한 계산유체역학의 활용에 대하여)

  • Kim Wu-Joan
    • Proceedings of the KSME Conference
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    • 2002.08a
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    • pp.5-8
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    • 2002
  • The issues associated with the application of CFD for ship design are addressed. It is quite certain that the CFD tools are very useful in evaluating hull forms a prior to traditional towing tank tests. However, the time-consuming pre-processing is an obstacle in the daily application of CFD tools to improve hull forms. The accuracy of computational modeling without sacrificing the usability of CFD system is also to be assessed. The wave generation is still predicted by using potential panel methods, while velocity profiles entering into propeller plane is solved using turbulent flow solvers. The choice of turbulence model is a key to predict nominal wake distribution within acceptable accuracy. The experimental data for CFD validation are invaluable to improve physical and numerical modeling. Other applications of CFD for ship design than hull form improvement are also given. It is certain that CFD can be a cost-effective tool for the design of new and better ships.

  • PDF

Analysis of body sliding along cable

  • Kozar, Ivica;Malic, Neira Toric
    • Coupled systems mechanics
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    • v.3 no.3
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    • pp.291-304
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    • 2014
  • Paper discusess a dynamic engineering problem of a mass attached to a pendulum sliding along a cable. In this problem the pendulum mass and the cable are coupled together in a model described by a system of differential algebraic equations (DAE). In the paper we have presented formulation of the system of differential equations that models the problem and determination of the initial conditions. The developed model is general in a sense of free choice of support location, elastic cable properties, pendulum length and inclusion of braking forces. Examples illustrate and validate the model.

Development of intregrated process control system for plasma etching utilizing neural network and genetic algorithm

  • Koh, Taek-Beom;Cha, Sang-Yeob;Woo, Kwang-Bang;Moon, Dae-Sik;Kwak, Kyu-Hwao;Chang, Ho-Seung
    • 제어로봇시스템학회:학술대회논문집
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    • 1995.10a
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    • pp.252-258
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    • 1995
  • The purpose of this study is to provide the integrated process control system, utilizing neural network modeling, to search for the appropriate choice input, and to keep the process output within the desired rang in the real etch process.

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Dynamic Interaction of Performance Information and Word-of-Mouth in Film Industry (영화공급사슬 내 성과정보와 입소문 효과의 동적상호작용에 대한 연구)

  • Lee, Wonhee
    • Korean Management Science Review
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    • v.32 no.2
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    • pp.125-143
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    • 2015
  • When studying the film industry, researchers have seldom addressed the dynamic interaction between marketing information and word of mouth in the motion picture industry mainly because of the limitation of traditional research methodologies. This study explores integration and competition among important variables influencing on audience's choice on movie selection, particularly by using a new method of agent-based modeling including competitive environment. Decision process of moviegoer composed of transition probability based on multinomial logit model, considering marketing and box-office information, critique, and word of mouth from other moviegoers. After validating the fitness of market share among released movies, this study conducted a set of simulation experiments considering several variables such as market size, change of weight between variables, and movie performance under competition. Propositions are derived from the simulation results is also suggested for future research.

Bootstrap simulation for quantification of uncertainty in risk assessment

  • Chang, Ki-Yoon;Hong, Ki-Ok;Pak, Son-Il
    • Korean Journal of Veterinary Research
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    • v.47 no.2
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    • pp.259-263
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    • 2007
  • The choice of input distribution in quantitative risk assessments modeling is of great importance to get unbiased overall estimates, although it is difficult to characterize them in situations where data available are too sparse or small. The present study is particularly concerned with accommodation of uncertainties commonly encountered in the practice of modeling. The authors applied parametric and non-parametric bootstrap simulation methods which consist of re-sampling with replacement, in together with the classical Student-t statistics based on the normal distribution. The implications of these methods were demonstrated through an empirical analysis of trade volume from the amount of chicken and pork meat imported to Korea during the period of 1998-2005. The results of bootstrap method were comparable to the classical techniques, indicating that bootstrap can be an alternative approach in a specific context of trade volume. We also illustrated on what extent the bias corrected and accelerated non-parametric bootstrap method produces different estimate of interest, as compared by non-parametric bootstrap method.

A Study of Data Mining Techniques in Bankruptcy Prediction (데이터 마이닝 기법의 기업도산예측 실증분석)

  • Lee, Kidong
    • Journal of the Korean Operations Research and Management Science Society
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    • v.28 no.2
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    • pp.105-127
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    • 2003
  • In this paper, four different data mining techniques, two neural networks and two statistical modeling techniques, are compared in terms of prediction accuracy in the context of bankruptcy prediction. In business setting, how to accurately detect the condition of a firm has been an important event in the literature. In neural networks, Backpropagation (BP) network and the Kohonen self-organizing feature map, are selected and compared each other while in statistical modeling techniques, discriminant analysis and logistic regression are also performed to provide performance benchmarks for the neural network experiment. The findings suggest that the BP network is a better choice among the data mining tools compared. This paper also identified some distinctive characteristics of Kohonen self-organizing feature map.