• Title/Summary/Keyword: parametric modeling

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Parametric modeling for the dielectric function of $Cd_{0.77}Mg_{0.23}Te$ alloy film

  • Ihn, Yong-Sub;Kim, Tae-Jung;Kim, Young-Dong
    • Journal of Korean Vacuum Science & Technology
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    • v.6 no.4
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    • pp.149-152
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    • 2002
  • We performed the modeling of the dielectric functions of C $d_{0.77}$M $g_{0.23}$Te by using parametric semiconductor model. Parametric model describes the analytic dielectric function as the summation of several energy-bounded Gaussian-broadened polynomials and provides a reasonably well parameterized function which can accurately reproduce the optical constants of semiconductor materials. We obtained the values of fitting parameters of the Mg composition 0.23 in the parametric model. From these parameters we could remove interference oscillations to obtain the dielectric function of C $d_{0.77}$M $g_{0.23}$Te alloy film for full 0.5-6.0 eV energy range.y range.

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Parametric Analysis and Design Engine for Tall Building Structures

  • Ho, Goman;Liu, Peng;Liu, Michael
    • International Journal of High-Rise Buildings
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    • v.1 no.1
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    • pp.53-59
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    • 2012
  • With the rise in CPU power and the generalization and popularity of computers, engineering practice also changed from hand calculations to 3D computer models, from elastic linear analysis to 3D nonlinear static analysis and 3D nonlinear transient dynamic analysis. Thanks to holistic design approach and current trends in freeform and contemporary architecture, BIM concept is no longer a dream but also a reality. BIM is not just providing a media for better co-ordination but also to shorten the round-the-clock time in updating models to match with other professional disciplines. With the parametric modeling tools, structural information is also linked with BIM system and quickly produces analysis and design results from checking to fabrication. This paper presents a new framework which not just linked the BIM system by means of parametric mean but also create and produce connection FE model and fabrication drawings etc. This framework will facilitate structural engineers to produce well co-ordinate, optimized and safe structures.

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 Geometric Constraint Solver for Parametric Modeling

  • Jae Yeol Lee;Kwangsoo Kim
    • Korean Journal of Computational Design and Engineering
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    • v.3 no.4
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    • pp.211-222
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    • 1998
  • Parametric design is an important modeling paradigm in CAD/CAM applications, enabling efficient design modifications and variations. One of the major issues in parametric design is to develop a geometric constraint solver that can handle a large set of geometric configurations efficiently and robustly. In this appear, we propose a new approach to geometric constraint solving that employs a graph-based method to solve the ruler-and-compass constructible configurations and a numerical method to solve the ruler-and-compass non-constructible configurations, in a way that combines the advantages of both methods. The geometric constraint solving process consists of two phases: 1) planning phase and 2) execution phase. In the planning phase, a sequence of construction steps is generated by clustering the constrained geometric entities and reducing the constraint graph in sequence. in the execution phase, each construction step is evaluated to determine the geometric entities, using both approaches. By combining the advantages of the graph-based constructive approach with the universality of the numerical approach, the proposed approach can maximize the efficiency, robustness, and extensibility of geometric constraint solver.

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A Translator for Parametrized Building Component Interoperability among Open BIM Support Software (개방형 BIM 지원 소프트웨어간 파라메트릭 건축부재 정보의 호환성 향상을 위한 변환기)

  • Kim, In-Han;Lee, Ji-Ah;Park, Seung-Hwa
    • Korean Journal of Computational Design and Engineering
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    • v.15 no.6
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    • pp.467-475
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    • 2010
  • Due to the needs of design optimization and productivity for modernized Korean traditional house, standardization of Korean traditional building components is proceeding by BIM (Building Information Modeling). Currently, most of BIM software support object-based parametric modeling. By means of parameterized Korean traditional building components, the shape and assembly relation can be controlled. Although IFC(ISO/PAS 16739), which is an international standard in the AEC field, has been developed for information exchange among BIM software, IFC and other existing common data formats cannot be exchangeable parametric information. For the exchangeable parametric information within IFC, the authors defined meta-data by using Pset(Property-Set). The authors analyzed results about interoperability test in Revit $Architecture^{TM}$, $ArchiCAD^{TM}$ and Digital $Project^{TM}$. In order to solve found problems, the authors developed a translator to improve interoperability among BIM software.

Slope Displacement Data Estimation using Principal Component Analysis (주성분 분석기법을 적용한 사면 계측데이터 평가)

  • Jung, Soo-Jung;Kim, Yong-Soo;Ahn, Sang-Ro
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.03a
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    • pp.1358-1365
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    • 2010
  • Estimating condition of slope is difficult because of nonlinear time dependency and seasonal effects, which affect the displacements. Displacements and displacement patterns of landslides are highly variable in time and space, and a unique approach cannot be defined to model landslide movements. Characteristics of movements are obtained by using a statistical method called Principal Component Analysis(PCA). The PCA is a non-parametric method to separate unknown, statistically uncorrelated source processes from observed mixed processes. In the non-parametric approaches, no physical assumptions of target systems are required. Instead, since the "best" mathematical relationship is estimated for given data sets of the input and output measured from target systems. As a consequence, non-parametric approaches are advantageous in modeling systems whose geomechanical properties are unknown or difficult to be measured. Non-parametric approaches are consequently more flexible in modeling than parametric approaches. This method is expected to be a useful tool for the slope management of and alarm systems.

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Automation in Site Planning of Apartment Complex - Through Rhino Grasshopper's Parametric Modeling and Optimization - (아파트 최적 배치 자동화 - Rhino Grasshopper를 활용한 parametric model의 최적화를 중심으로 -)

  • Sung, Woo-Jae;Jeong, Yo-Han
    • Journal of KIBIM
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    • v.10 no.3
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    • pp.22-32
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    • 2020
  • Apartment building site planning is one of time consuming and labor-intensive tasks in architectural design field, due to its complexity in zoning regulations, building codes, local restrictions, and site-specific conditions. In other words, the process can be seen as a very complicated mathematical function with layers of variables and parameters, which ironically can be automated using computational methods on parametric tools. In this paper, a practical method of automating site planning of an apartment complex has been proposed by utilizing parametric approaches in Rhino 3D and Grasshopper. Two primary parameters, building heights and positions, determine the efficacy of building layouts under all regulatory standards, thus testing out numerous combinations of the two will produce some successful layout alternatives. For this, equation solver has been used for iterating the parametric model to sort out meaningful results among others. It also has been proven that the proposed process significantly reduced the time in site planning down to less than an hour on most cases, and many successful alternatives could be obtained by using multiple computers. Post evaluation processes such as day light and view shed analysis helped sort out the best performing ones out of functioning alternatives.

Reliability Analysis Using Parametric and Nonparametric Input Modeling Methods (모수적·비모수적 입력모델링 기법을 이용한 신뢰성 해석)

  • Kang, Young-Jin;Hong, Jimin;Lim, O-Kaung;Noh, Yoojeong
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.30 no.1
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    • pp.87-94
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    • 2017
  • Reliability analysis(RA) and Reliability-based design optimization(RBDO) require statistical modeling of input random variables, which is parametrically or nonparametrically determined based on experimental data. For the parametric method, goodness-of-fit (GOF) test and model selection method are widely used, and a sequential statistical modeling method combining the merits of the two methods has been recently proposed. Kernel density estimation(KDE) is often used as a nonparametric method, and it well describes a distribution function when the number of data is small or a density function has multimodal distribution. Although accurate statistical models are needed to obtain accurate RA and RBDO results, accurate statistical modeling is difficult when the number of data is small. In this study, the accuracy of two statistical modeling methods, SSM and KDE, were compared according to the number of data. Through numerical examples, the RA results using the input models modeled by two methods were compared, and appropriate modeling method was proposed according to the number of data.

Information Modeling for BIM Based Design of Precast Concrete Platform (BIM 기반의 설계를 위한 프리캐스트 콘크리트 승강장의 정보모델링)

  • Jeong, Ji-Sook;Lee, Kwang-Myong;Park, Ki-Hyun;Park, Young-Shik
    • Journal of KIBIM
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    • v.4 no.1
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    • pp.1-7
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    • 2014
  • The construction method using PC(Precast Concrete) has been widely used because the method can shorten the construction period and improve construction quality. In this paper, through the analysis of present design process for PC railway platform, design parameters on the geometry and properties were extracted and 3D information models for PC railway platform were constructed by the parametric modeling technique. Furthermore, the interface module was developed to link 3D models to the structural analysis/design sheet and database program using VBA(Visual Basic Application). This information model could be used in various areas including structural analysis and design, 2D drawing, quantity estimation and 4D simulation including clash detection.

3D Tunnel Modeling by Parametric Representation of Geometry (매개변수식 기하 표현법에 의한 3차원 터널 모델링)

  • 이형우;신대석
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.15 no.1
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    • pp.33-42
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    • 2002
  • A method of automatic 3D tunnel modeling is proposed. The proposed method used the parametric representation of geometry and a hierarchical and relational data structure. These two bases provide the generalization and extension for 3D tunnel modeling. Especially, these two fundamentals ion the basis iota representing the characteristics of the tunnel structure for analysis. The constant-curvature characteristic is exploited to generate 3D mesh on the tunnel surface. This is attributed to the advantage that any 2D automatic mesh generation algorithm can be applied to 3D mesh modeling.