• 제목/요약/키워드: empirical modeling

검색결과 982건 처리시간 0.026초

객체지향 기반의 정보시스템 개발 프로젝트에서의 기능점수 예측 기법에 관한 연구 (Estimating the Function Point for the Object Oriented Information Systems)

  • 정승렬;이석준
    • 한국정보시스템학회지:정보시스템연구
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    • 제16권1호
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    • pp.111-133
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    • 2007
  • The purpose of this study is to present a new function point estimation approach for the Object-Oriented information systems. In order to fulfill this purpose, we first review the literature on Function Point Analysis of IFPUG, Unified Modeling Language, and Unified Process. Then, we derive a method and rules for estimating Function Points based on Use Cases and Class Diagrams. To analyze the appropriateness of the proposed approach, we conduct the empirical testing. 143 use cases are collected from production, marketing, distribution, sales, and other areas from the Object-Oriented systems development projects. We compare our new approach with the existing methods that are usually used for traditional systems development projects. The results show that our proposed approach is more appropriate for the Object-Oriented environment.

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NMG 염색법과 화상처리를 이용한 도정도 모델링 (Modeling of Milling Degree for Milled Rice using NMG Dying and Image Processing)

  • 윤두현;김의웅;김훈
    • Journal of Biosystems Engineering
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    • 제31권6호
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    • pp.524-528
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    • 2006
  • This study was performed to develop experimental model for milling degree and whiteness from analysis the CBB (colored bran balance) index using NMG dying and image processing. The endosperm layer increased and the pericarp, aleurone layer and CBB index decreased as the milling degree and whiteness increased. So, CBB index was closely linked to milling degree and whiteness. A empirical CBB index model was developed according to the milling degree and whiteness. The model were found to fit adequately to all test data with a coefficient of determination of 0.99, and therefore the CBB model proved to be quite applicable.

신제품 개발을 위한 통합 고객만족도 평가모델에 관한 실증적 연구 - 자동차 산업을 중심으로 - (An Empirical Study on the Integrated Customer Satisfaction Evaluation Model for New Product Development - Focused on Automobile Industry -)

  • 김동남;조재림
    • 품질경영학회지
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    • 제32권4호
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    • pp.113-124
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    • 2004
  • Customer satisfaction is becoming an increasingly salient topic in many firms and in academic research. One main rationale behind this interest is that customer satisfaction is believed to be associated with fruitful customer re-visit from the firm's point of view. Some country already had index models which can measure the degree of customer satisfaction. But, such models are ordinary models which used generally the scope of nation-wide /industry. Therefore, we needs some modifications to measure customer satisfaction for specific product & service and to provide the valuable feedback to specific firms. In this Perspectives, this study will evaluate the customer satisfaction index about automobile company and analyze it's result for valuable feedback. This study will present a model for an integrated customer satisfaction evaluation system which used structural equation modeling. Through this study, we anticipate that it will offer the measuring method about customer satisfaction and some guideline for product design process.

단순 비선형 모델을 이용한 자동차 충격흡수기의 동특성 모델링 기법 연구 (Dynamic Modeling of Automotive Shock Absorbers Using Simple Nonlinear Models)

  • 한형석;서정원;노규석;허승진;김기훈
    • 한국자동차공학회논문집
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    • 제11권5호
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    • pp.156-162
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    • 2003
  • The shock absorber is a part having a direct influence on the ride comfort, stability and dynamic load prediction of a vehicle. Thus, a rationally modeled shock absorber should be required in the dynamic analysis of vehicles. This thesis presents a modified model, based on Worden's hyperbolic tangent function, in order to fit experimental data on the velocity-damping force of a shock absorber. The hyperbolic tangent function correctly indicates the characteristics of a shock absorber, and has the advantage of containing physical causality. To evaluate the method, comparative evaluations of the linear model, the 5th polynomial model and Worden's model were carried out. The function presented in this paper is not only simple but also makes it possible to estimate the function coefficients easily and visually. In addition, it has the advantage of containing physical causality. Lastly, it effectively models the damping force of a shock absorber.

신경망을 이용한 현가시스템의 모델링 및 고장 진단에 관한 연구 (A Study on Modeling and Fault Diagnosis of Suspension Systems Using Neural Network)

  • 이정호;박기홍;허승진
    • 한국자동차공학회논문집
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    • 제11권1호
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    • pp.95-103
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    • 2003
  • Driving safety of a vehicle is largely influenced by the damper and the tire. Developed in this research is a fault diagnosis algorithm for the two components so that the driver can be promptly informed when fault occurs in one or both of them. To this end, the damper and the tire were modeled using the neural network from their experimental data, and fault diagnosis was made using frequency responses of the damping force and the dynamic wheel force. The algorithm was tested via experiments, and it demonstrated successful diagnostic performance under various driving conditions.

Analytical Rapid Prediction of Tsunami Run-up Heights: Application to 2010 Chilean Tsunami

  • Choi, Byung Ho;Kim, Kyeong Ok;Yuk, Jin-Hee;Kaistrenko, Victor;Pelinovsky, Efim
    • Ocean and Polar Research
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    • 제37권1호
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    • pp.1-9
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    • 2015
  • An approach based on the combined use of a 2D shallow water model and analytical 1D long wave run-up theory is proposed which facilitates the forecasting of tsunami run-up heights in a more rapid way, compared with the statistical or empirical run-up ratio method or resorting to complicated coastal inundation models. Its application is advantageous for long-term tsunami predictions based on the modeling of many prognostic tsunami scenarios. The modeling of the Chilean tsunami on February 27, 2010 has been performed, and the estimations of run-up heights are found to be in good agreement with available observations.

R407C 및 R290 냉매에 대한 모세관내 유동특성 실험 및 모델링 (Experimentation and modeling on the flow of R407c and R290 through capillary tubes)

  • 김용찬;조일용;최종민
    • 설비공학논문집
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    • 제11권4호
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    • pp.492-498
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    • 1999
  • Mass flow rates of R407C and R290 through capillary tubes were measured with various capillary tube geometries and flow conditions. For all refrigerants tested in the present study, mass flow rate through the capillary tube was strongly dependent on the condensing pressure, subcooling and capillary length and diameter. The flow rate of R407C was 5~10[%] higher than that of R22 at the same condensing temperature and degree of subcooling, while flow rate for R290 was 40[%] lower than that for R22. Based on experimental results, an empirical correlation was developed using Pi theorem to predict the mass flow rate through capillary tubes. The predicted flow rates using the model were consistent with the experimental data within ${\pm}$10[%].

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Hydrodynamics of single-deadrise hulls and their catamaran configurations

  • Bari, Ghazi S.;Matveev, Konstantin I.
    • International Journal of Naval Architecture and Ocean Engineering
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    • 제9권3호
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    • pp.305-314
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    • 2017
  • Asymmetric planing hulls are often used on high-speed catamarans. In this study, a linearized potential-flow method is applied for modeling steady hydrodynamics of single asymmetric hulls and their catamaran setups. Numerical results are validated with available experimental data and empirical correlations. Parametric calculation results are presented for the lift coefficient and the center of pressure for variable hull geometry, spacings, and speed regimes. The lift coefficient is found to increase at smaller hull spacings and decrease at higher Froude numbers and higher deadrise angles.

MODELING OF THE BAINITE TRANSFORMATION KINETICS IN C-MN-MO-NI STEEL WELD CGHAZ

  • Sangho Uhm;Lee, Changhee;Kim, Joohak;JunhwaHong
    • 대한용접접합학회:학술대회논문집
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    • 대한용접접합학회 2002년도 Proceedings of the International Welding/Joining Conference-Korea
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    • pp.276-281
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    • 2002
  • A metallurgical model for bainite transformation kinetics in the coarse-grained heat affected zone(CGHAZ) on the basis of an Avrami-type equation was studied. Isothermal transformation tests were carried out to obtain the empirical equations for incubation time and Avrami kinetic constants for C-Mn-Mo-Ni steel. The effect of prior austenite grain size(PAGS) on the reaction rate of bainite was also investigated. Compared with experimental transformation behavior of bainite, the predicted behavior was in good agreement. It was also found that a smaller grain size retard the bainite reaction rate, contrary to the classical grain size effect and this is considered to be caused by constraint of grain size to bainite growth.

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REYNOLDS STRESS MODELING OF OPEN-CHANNEL FLOWS OVER BEDFORMS

  • Choi, Sung-Uk;Kang, Hyeong-sik
    • Water Engineering Research
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    • 제3권4호
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    • pp.247-258
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    • 2002
  • This paper presents a non-isotropic turbulence modeling of flows over bedforms. The Reynolds stress model is used for the turbulence closure. In the model, Launder, Reece, and Rodi's model and Hanjalic and Launder's model are employed f3r the pressure strain correlation term and the diffusion term, respectively. The mean flow and turbulence structures are simulated and compared with profiles measured in the experiments. The numerical solutions from two-equation turbulence models are also provided for comparisons. The Reynolds stress model yields the separation length of eddy similar to the other numerical results. Using the developed model, the resistance coefficients are also estimated for the flows at different Froude numbers. Karim's (1999) relationship is used to determine the bedform geometry. It is found that the values of the form drag and the skin friction are very similar to those obtained by the other turbulence models. meaning higher values of the form drag and lower values of the skin friction compared with the empirical formulas.

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