• Title/Summary/Keyword: Parametric Model

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A Macro Parametric Data Representation far CAD Model Exchange using XML (CAD 모델 교환을 위한 매크로 파라메트릭 정보의 XML 표현)

  • 양정삼;한순흥;김병철;박찬국
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.27 no.12
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    • pp.2061-2071
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    • 2003
  • The macro-parametric approach, which is a method of CAD model exchange, has recently been proposed. CAD models can be exchanged in the form of a macro file, which is a sequence of modeling commands. As an event-driven commands set, the standard macro file can transfer design intents such as parameters, features and constraints. Moreover it is suitable for the network environment because the standard macro commands are open, explicit, and the data size is small. This paper introduces the concept of the macro-parametric method and proposes its representation using XML technology. Representing the macro-parametric data using XML allows managing vast amount of dynamic contents, Web-enabled distributed applications, and inherent characteristic of structure and validation.

Development of a Parametric Simulation Model by a Model Integration Method for Production System with Robots (모델 접속 기법에 의한 로봇 응용 생산시스템의 파라메트릭 시뮬레이션모델 개발)

  • Kuk, Kum-Hoan
    • Journal of the Korean Society for Precision Engineering
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    • v.12 no.5
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    • pp.136-148
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    • 1995
  • In this study, a model integration method is pressented as a new method for development of a parametric simulation model. This method enable us to integrate the special simulation models for each production subsystem into a large simulation model. Not only this large simulation model but also each special simulation model for each production subsytem can be used independently. Using this integration method man can reduce the development time and cost for simulation model development. To show the usefulness of this method, a simulation model for a production system with robots is developed by this model integration method. This simulation model is realized by the integration of two special simulation models, one model for a machining subsystem and the other model for a transport subsystem. The modeled production system consists of the robotic cells for machining and a transport subsystem which enable the material flow among the robotic cells. The flow of workpiece in each robotic cell is not fixed. All machines in a robotic cell are only served by robots.

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Optimization of a twin-skeg container vessel by parametric design and CFD simulations

  • Chen, Jingpu;Wei, Jinfang;Jiang, Wujie
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.8 no.5
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    • pp.466-474
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    • 2016
  • The model tests results for the original lines of an 10000TEU container vessel show that the delivered power is higher and could not satisfy the requirement of energy saving effects and design targets. In this paper, the lines optimization of the 10,000 twin-skeg container vessel was carried out by parametric modeling and CFD simulations. At first, the CFD methods for twin-skeg hull form were validated by the comparison with the experimental results. Then more than one hundred parameters were adopted for the establishment of the fully parametric model. Based on the parametric model of the twin-skeg container vessel, the preliminary optimization was carried out by tight coupling of FRIENDSHIP-FRAMEWORK with potential flow of SHIPFLOW. Then several important parameters related to the after part of twin-skeg vessel were investigated by viscous flow computation. The final optimized variant PM11, which the total resistance was reduced by about 8.3% in model scale, is obtained within the constraints of general arrangement. And the model tests for variant PM11 was carried out in CSSRC, which shows that the resistance of optimized variant PM11 is decreased by about 8.6%.

Energy Analysis of System Constraints using SysML Parametric Diagram (SysML Parametric 다이어그램을 이용한 시스템 제약사항의 소모전력 분석)

  • Lee, Jae-Wuk;Hong, Jang-Eui
    • Journal of Convergence Society for SMB
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    • v.2 no.2
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    • pp.13-19
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    • 2012
  • Various quality requirements have increased in developing embedded systems. One of those requirements in mobile embedded system is to reduce energy consumption because of limited power supply. Especially as the complexity of embedded software is increased, the interests of the software energy consumption analysis is also increased. In recent years, some studies has been carried out model-based analysis because it can be able to reflect energy consumption requirements in design phase. In this paper, we proposes a model-based energy analysis technique using SysML parametric diagram. The proposed technique designs software activity model using characteristics of parametric diagram, and then energy consumption value by the execution of the model is derived. Our technique has merit that can perform tradeoffs analysis for energy quality property between different implementations.

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Semiparametric mixture of experts with unspecified gate network

  • Jung, Dahai;Seo, Byungtae
    • Journal of the Korean Data and Information Science Society
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    • v.28 no.3
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    • pp.685-695
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    • 2017
  • The traditional mixture of experts (ME) modeled the gate network using a certain parametric function. However, if the assumed parametric function does not properly reflect the true nature, the prediction strength of ME would become weak. For example, the parametric ME often uses logistic or multinomial logistic models for the network model. However, this could be very misleading if the true nature of the data is quite different from those models. Although, in this case, we may develop more flexible parametric models by extending the model at hand, we will never be free from such misspecification problems. In order to alleviate such weakness of the parametric ME, we propose to use the semi-parametric mixture of experts (SME) in which the gate network is estimated in a non-parametrical way. Based on this, we compared the performance of the SME with those of ME and neural networks via several simulation experiments and real data examples.

Systematic Development of Parametric Translators by Measuring Semantic Distance between CAD Data Models (CAD 데이터 모델들간의 의미거리 계산을 통한 파라메트릭 번역기의 체계적 개발)

  • Kim, Jun-Hwan;Mun, Du-Hwan
    • Korean Journal of Computational Design and Engineering
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    • v.14 no.3
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    • pp.159-167
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    • 2009
  • For the robust exchange of parametric CAD model data, it is very important to perform mapping rightly and accurately between different CAD models. However, data model mapping is usually performed on a case-by-case basis. This results in the problem that mapping quality fluctuates very widely depending on the abilities of developers. In order to solve this problem, the concept of symantic distance is adapted and applied to the translation of parametric CAD model data in order to measure the difference between different CAD models quantitatively in a computer-interpretable form and systematize the mapping process.

ML estimation using Poisson HGLM approach in semi-parametric frailty models

  • Ha, Il Do
    • Journal of the Korean Data and Information Science Society
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    • v.27 no.5
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    • pp.1389-1397
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    • 2016
  • Semi-parametric frailty model with nonparametric baseline hazards has been widely used for the analyses of clustered survival-time data. The frailty models can be fitted via an auxiliary Poisson hierarchical generalized linear model (HGLM). For the inferences of the frailty model marginal likelihood, which gives MLE, is often used. The marginal likelihood is usually obtained by integrating out random effects, but it often requires an intractable integration. In this paper, we propose to obtain the MLE via Laplace approximation using a Poisson HGLM approach for semi-parametric frailty model. The proposed HGLM approach uses hierarchical-likelihood (h-likelihood), which avoids integration itself. The proposed method is illustrated using a numerical study.

Generic Modeling System (Generic Modeling System 개발 및 응용사례)

  • 조유정;임기수;나재일;이장열
    • CDE review
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    • v.3 no.3
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    • pp.36-45
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    • 1997
  • This paper presents the research on the development of Generic modeling system as a 3D CAD customizing system for the elevator design. This system enables to create a generic model which gives birth to many models. The generic model is expressed as a non-scale model or a standard model in this paper. Using the parametric design techniques, all their relationships are explicitly represented in the tables, not represented in implicit embedded coding. Owing to this method, designers can easily extend the generic model to contain more model families. All parametric relations are stored in relational database. A designer can retrieve various models from a generic model automatically, by using some key input values.

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A Comparison on the Reproducibility of Parametric Bodies Used in the Virtual Garment System

  • Choi, Hee Eun;Nam, Yun Ja;Kim, Hye Suk
    • Fashion & Textile Research Journal
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    • v.16 no.2
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    • pp.266-274
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    • 2014
  • Parametric bodies reproduce the actual shape of human body parts and should be convenient for general users to change size to judge the visual fit of clothes on-line. In this study, three parametric bodies(i.e. I, C, D ) were compared to verify the accuracy of the provided body dimensions and reproducibility to a target model. To compare reproducibility, the 20s female standard virtual model developed for an apparel industry by Korean agency for technology and standards is used. The investigation of existing parameters showed that the numbers and kinds of parameters provided by each program were different with some errors in notation; in addition, some of virtual body dimensions went beyond the maximum allowable error. The result of changing each parametric body to the 20s female standard body showed that D, C, I in order produced better reproducibility for body dimensions. There were different levels of protrusion and concavity in the virtual cross sections and virtual longitudinal sections despite the small differences in body dimensions and cross sectional areas; in addition, some parametric body was not bilateral symmetry. The results of this study can be used as basic information in the standardization of a virtual model used in a virtual garment program.

Survival Analysis of Patients with Breast Cancer using Weibull Parametric Model

  • Baghestani, Ahmad Reza;Moghaddam, Sahar Saeedi;Majd, Hamid Alavi;Akbari, Mohammad Esmaeil;Nafissi, Nahid;Gohari, Kimiya
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.18
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    • pp.8567-8571
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    • 2016
  • Background: The Cox model is known as one of the most frequently-used methods for analyzing survival data. However, in some situations parametric methods may provide better estimates. In this study, a Weibull parametric model was employed to assess possible prognostic factors that may affect the survival of patients with breast cancer. Materials and Methods: We studied 438 patients with breast cancer who visited and were treated at the Cancer Research Center in Shahid Beheshti University of Medical Sciences during 1992 to 2012; the patients were followed up until October 2014. Patients or family members were contacted via telephone calls to confirm whether they were still alive. Clinical, pathological, and biological variables as potential prognostic factors were entered in univariate and multivariate analyses. The log-rank test and the Weibull parametric model with a forward approach, respectively, were used for univariate and multivariate analyses. All analyses were performed using STATA version 11. A P-value lower than 0.05 was defined as significant. Results: On univariate analysis, age at diagnosis, level of education, type of surgery, lymph node status, tumor size, stage, histologic grade, estrogen receptor, progesterone receptor, and lymphovascular invasion had a statistically significant effect on survival time. On multivariate analysis, lymph node status, stage, histologic grade, and lymphovascular invasion were statistically significant. The one-year overall survival rate was 98%. Conclusions: Based on these data and using Weibull parametric model with a forward approach, we found out that patients with lymphovascular invasion were at 2.13 times greater risk of death due to breast cancer.