• Journal of Korea Multimedia Society
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• v.19 no.11
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• pp.1900-1908
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• 2016

Recent times have seen the introduction of modeling technologies using implicit surface and marching cubes algorithm in the field of computer graphics. Implicit surface modeling is used to express characters or fluid. This study presents a calculation method for the density of curve skeletal primitives using parametric curve and implements an implicit surface modeling tool by utilizing Maya API. Skeletal primitives can be assembled and utilized in character modeling using the implemented modeling tool. Results could be obtained more effectively compared to existing particle-based methods.

• Korean Journal of Computational Design and Engineering
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• v.3 no.3
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• pp.168-176
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• 1998

This paper deals with an application on the mould machining of air intake hose product by using 3-dimensional parametric modeling techniques. The detailed domain is the 3-dimensional product with similar shapes and different sizes which needs too much working time for preparation of modeling or machining due to making a trial and errors repeatedly. Decision making rules for selection of modeling order and technique, and for calculation of cutting conditions, and for determination of sequence and method concerning machining operations are required by interview of expert engineers in the field. The developed expert system of modeling and machining is programmed by using a user programming language under the CAD/CAM software of the Personal Designer. The developed system that aids a mould engineer who is working in the modeling and machining section which deal with air intake hose product provides strong and useful capabilities.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.47 no.8
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• pp.566-573
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• 2019

In order to obtain high-quality images by motion compensation in the airborne synthetic aperture radar (SAR), accurate motion sensing in image acquisition section is necessary. Especially, reducing relative position error and discontinuity in motion sensing is important. To overcome the problem, we propose a pre-parametric error modeling (P-PEM) algorithm which is a real-time motion sensing algorithm for the airborne SAR in this paper. P-PEM is an extended version of parametric error modeling (PEM) method which is a motion sensing algorithm to mitigate the errors in the previous work. PEM estimates polynomial coefficients of INS error which can be assumed as a polynomial in the short term. Otherwise, P-PEM estimates polynomial coefficients in advance and uses at image acquisition section. Simulation results show that the P-PEM reduces relative position error and discontinuity effectively in real-time.

• Korean Institute of Interior Design Journal
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• v.25 no.6
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• pp.70-78
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• 2016

This paper aims to describe a case study of parametric interior design based on BIM (Building Information Modeling). As the practical use of BIM-based design grows, its influence expands into the field of interior architecture design. BIM makes possible to check various design plan, reach decision making in an effective way, and change design plan in an efficient method. Therefore, BIM is also promising field in interior architecture design. However, compared to other fields in architecture, engineering, and construction (AEC) industry, there have been less research and projects on BIM in the field of interior architecture. For increasing the feasibility of adapting BIM in interior architecture design, this paper describes a case study-projecting images for designing interior panels using parametric modeling. This process needs elaborate, delicate, and precise steps for harmonious output. For continuous use of building, users look forward to the design which variable and changeable according to user's preference and environment. Therefore, demand for parametric design in the interior design part such as panel pattern design for various decoration is growing. Treated process in this paper deals with an advanced phase which much effective in decreasing time consumption and useless part of process. Finally, this paper suggests the possibility of using BIM in the interior design process and field where BIM can be applied.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.11
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• pp.6751-6755
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• 2013

Background: Research on cancers with a high rate of mortality such as those occurring in the stomach requires using models which can provide a closer examination of disease processes and provide researchers with more accurate data. Various models have been designed based on this issue and the present study aimed at evaluating such models. Materials and Methods: Data from 330 patients with gastric cancer undergoing surgery at Iran Cancer Institute from 1995 to 1999 were analyzed. Cox-Snell Residuals and Akaike Information Criterion were used to compare parametric and semi-parametric Cox models in modeling transition rates among different states of a multi-state model. R 2.15.1 software was used for all data analyses. Results: Analysis of Cox-Snell Residuals and Akaike Information Criterion for all probable transitions among different states revealed that parametric models represented a better fitness. Log-logistic, Gompertz and Log-normal models were good choices for modeling transition rate for relapse hazard (state $1{\rightarrow}state$ 2), death hazard without a relapse (state $1{\rightarrow}state$ 3) and death hazard with a relapse (state $2{\rightarrow}state$ 3), respectively. Conclusions: Although the semi-parametric Cox model is often used by most cancer researchers in modeling transition rates of multistate models, parametric models in similar situations- as they do not need proportional hazards assumption and consider a specific statistical distribution for time to occurrence of next state in case this assumption is not made - are more credible alternatives.

• Journal of KIBIM
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• v.2 no.2
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• pp.37-45
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• 2012

Modular bridge construction enabling better productivity of design and construction by standardized members and robotic construction becomes an important issue in construction industry. Modular structures needs accurate information delivery between design, fabrication and construction processes. BIM (Building Information Modeling) based parametric modeling was proposed for the modular bridge substructure. Considering ranges of parameters of the modular bridge, fixed value, variables and relations were defined and these parametric models were applied to design, analysis and fabrication. Experience from development of new structures can be embedded in the 3D models, and the models provide efficient and precise knowledge delivery.

• International Journal of Aeronautical and Space Sciences
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• v.16 no.3
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• pp.370-379
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• 2015

Handling constantly evolving configurations of aircraft can be inefficient and frustrating to design engineers, especially true in the early design phase when many design parameters are changeable throughout trade-off studies. In this paper, a physics-based design framework using parametric modeling is introduced, which is designated as DIAMOND/AIRCRAFT and developed for structural design of transport aircraft in the conceptual and preliminary design phase. DIAMOND/AIRCRAFT can relieve the burden of labor-intensive and time-consuming configuration changes with powerful parametric modeling techniques that can manipulate ever-changing geometric parameters for external layout of design alternatives. Furthermore, the design framework is capable of generating FE model in an automated fashion based on the internal structural layout, basically a set of design parameters describing the structural members in terms of their physical properties such as location, spacing and quantities. The design framework performs structural sizing using the FE model including both primary and secondary structural levels. This physics-based approach improves the accuracy of weight estimation significantly as compared with empirical methods. In this study, combining a physics-based model with parameter modeling techniques delivers a high-fidelity design framework, remarkably expediting otherwise slow and tedious design process of the early design phase.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.8
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• pp.727-731
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• 2000

This paper presents a new practical autopilot design approach to acceleration control for tail-controlled STT(Skid-to-Turn) missiles. The approach is novel in that the proposed parametric affine missile model adopts acceleration as th controlled output and considers the couplings between the forces as well as the moments and control fin deflections. The aerodynamic coefficients in the proposed model are expressed in a closed form with fittable parameters over the whole operating range. The parameters are fitted from aerodynamic coefficient look-up tables by the function approximation technique which is based on the combination of local parametric models through curve fitting using the corresponding influence functions. In this paper in order to employ the results of parametric affine modeling in the autopilot controller design we derived a parametric affine missile model and designed a feedback linearizing controller for the obtained model. Stability analysis for the overall closed loop sys-tem is provided considering the uncertainties arising from approximation errors. the validity of the proposed modeling and control approach is demonstrated through simulations for an STT missile.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.23 no.4
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• pp.417-424
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• 2010

This study proposes a parametric modeling method for efficient preliminary design of FCM(Free Cantilever Method) bridge. The method is capable of automatic fitting of cross section according to variation of span length of box girder which has variational section. Parameters for forming longitudinal geometry of box girder are defined, then implicit and explicit constraints, and functional relations among them are defined by applying statistics of parameters used in FCM bridge designs. The constraints and relations are applied to a sample bridge for verifying applicability of parametric modeling. In addition, material quantity of the sample model generated by parametric modeling is estimated and compared to the quantity of the real designed model to check the accuracy of the automatically designed parametric model.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.23 no.57
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• pp.87-92
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• 2000

This paper describes a three dimensional parametric modeling system for transmission gears of tractor. In conventional design and manufacturing, information about three dimensional shapes has been described in engineering drawings. However drawing based design presents several problems; 1) communication errors between the designer and the modeller or manufacturer. 2) time taken and costs incurred in the design process. To solve these problems the system of parametric design based modeling has been proposed. Developed system in this paper consists of four steps; 1) parametric design of transmission gears with a solid modeler. 2) evaluation of gear geometry and strength. 3) dynamic simulation for gear interference check. 4) gear stress analysis with a CAE software. The proposed system has been tested in the fields and found to be a useful system.