• Title/Summary/Keyword: Convex Modeling

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Study on the Airfoil Shape Design Optimization Using Database based Genetic Algorithms (데이터베이스 기반 유전 알고리즘을 이용한 효율적인 에어포일 형상 최적화에 대한 연구)

  • Kwon, Jang-Hyuk;Kim, Jin;Kim, Su-Whan
    • Journal of Advanced Marine Engineering and Technology
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    • v.31 no.1
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    • pp.58-66
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    • 2007
  • Genetic Algorithms (GA) have some difficulties in practical applications because of too many function evaluations. To overcome these limitations, an approximated modeling method such as Response Surface Modeling(RSM) is coupled to GAs. Original RSM method predicts linear or convex problems well but it is not good for highly nonlinear problems cause of the average effect of the least square method(LSM). So the locally approximated methods. so called as moving least squares method(MLSM) have been used to reduce the error of LSM. In this study, the efficient evolutionary GAs tightly coupled with RSM with MLSM are constructed and then a 2-dimensional inviscid airfoil shape optimization is performed to show its efficiency.

Adaptive Video-Dissolve Detection Method Based on Correlation Between Two Scenes

  • Won, Jong-Un;Park, Jae-Gark;Chung, Yoon-su;Park, Kil-Houm
    • Proceedings of the IEEK Conference
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    • 2002.07c
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    • pp.1519-1522
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    • 2002
  • In this paper, we propose a new adaptive dissolve detection method based on the analysis of a dissolve modeling error that is the difference between an ideally modeled dissolve curve without any correlation and an actual variance curve with a correlation. The dissolve modeling error is determined based on a correlation between two scenes and variances for each scene. First, Candidate regions are extracted by using the characteristics of a parabola that is downward convex, then the candidate region will be verified based on a dissolve modeling error. If a dissolve modeling error on a candidate region is less than a threshold that is defined by a dissolve modeling error with a target correlation, the candidate region should be a dissolve region with a correlation less than the target correlation. The threshold is adaptively determined based on the variances between the candidate regions and the target correlation. By considering the correlation between neighbor scenes, the proposed method is able to be a semantic scene-change detector. The proposed algorithm was tested on various types of data and its performance proved to be more accurate and reliable when compared with other commonly used methods

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Analytic Outage Cost and Marginal Cost Evaluation in Generation Planning (전원계측에서의 공급지장비와 자계비용의 해석적 추정에 관한 연구)

  • Bong-Yong Lee;Chung-Hoon Kim;Young-Moon Park
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.32 no.2
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    • pp.33-42
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    • 1983
  • Outage cost inclusion in operational simulation is very important subject in generation planning. Conventional discretized one in probabilistic simulation has unavoidably insufficient modeling and costly computation time. Now that the analytic operational simulation is possible, the outage cost inclusion is desired. With this inclusion the objective function of operational simulation becomes convex, so that analytic manipulation is easier. The derivation of outage cost is made in this paper, and the effects is evaluated. Further marginal cost is mentioned.

Intelligent Digital Controller Using Digital Redesign

  • Joo, Young-Hoon
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.3 no.2
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    • pp.187-193
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    • 2003
  • In this paper, a systematic design method of the intelligent PAM fuzzy controller for nonlinear systems using the efficient tools-Linear Matrix Inequality and the intelligent digital redesign is proposed. In order to digitally control the nonlinear systems, the TS fuzzy model is used for fuzzy modeling of the given nonlinear system. The convex representation technique also can be utilized for obtaining TS fuzzy models. First, the analog fuzzy-model-based controller is designed such that the closed-loop system is globally asymptotically stable in the sense of Lyapunov stability criterion. The simulation results strongly convince us that the proposed method has great potential in the application to the industry.

A Study on the Transplantation Methods of Large Trees - The Case of Celtis Sinensis in Chonan and Ginkgo biloba in Andong - (대형 수목의 이식공법 - 천안시 팽나무와 안동시 은행나무 사례 -)

  • 임재홍;이재근;김학범
    • Journal of the Korean Institute of Landscape Architecture
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    • v.30 no.4
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    • pp.92-104
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    • 2002
  • This study investigates, analyzes, and summarizes Dansplantation techniques and methods through practical methodology centering on fieldwork in order to present effective planting methods for large trees that have important significance. The conclusions are as follows : 1. The transplantation process of a large tree generally consists of the stages of digging up a tree, manufacturing a carrier frame, loading the tee on a vehicle, transporting, transplanting the tree, installing a strut and maintaining and managing the new transplant. In addition, planting a tree on a mounted place includes the primary procedures of trimming out the root, and preparing for transplanting the tree on a mounted place, as well as the secondary work of trimming out the root, transplanting a tree on a mounted place, maintenance and management. 2. In order to decide on a transplantation method for a large-sized tree, a structure calculation has to be performed first. That is, one must calculate the weight of the tree and the allowable stress of the strut (H-beam, etc.) fhst and then decide on the upper method through computer modeling based upon this structural calculation. 3. As a result of the analysis of a transplanted tree using the life soil method, it was confirmed that large quantities of feeder roots had developed around the root within a short time after the transplantation. The life soil method has proven to be very effective for transplantation of large-sized trees. 4. As for the production method of an H-beam strut frame, it was found that the manufacturing process and disassembly process were simple and proper; therefore, the H-beam frame is an appropriate structure to be used in the transplantation of large trees. 5. The concavo-convex method, which consists of filling the life soil in the concavo-convex area around the root, was found to be a method that promotes the growth of feeder roots within a short period of time and saves the supply of water at the same time.

Development of a Spatial Subdivision Technique using BIM for Space Syntax Analysis of a Korean Traditional House (BIM을 이용한 전통 한옥의 공간구문 분석을 위한 공간분할기법 개발)

  • Jeong, Sang Kyu
    • KIEAE Journal
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    • v.10 no.3
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    • pp.57-62
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    • 2010
  • To effectively use Building Information Modelling (BIM) dealing with semantic information including the entities of building components, the information about building components should be standardized. Like standardized modern buildings. in the past, Korean traditional houses were built according to strict procedures and formats. Therefore, if the Korean traditional house are modelled by using BIM,. not only the Korean traditional house of good quality will be built quickly and cheaply, but also spaces in the existing Korean traditional house will be easily analyzed. However, when analyzing spaces of the Korean traditional house using Space Syntax, some problems are caused in dividing outdoor space such as yard with unclear boundaries, unlike indoor space with clear boundaries surrounded by walls. These comes from the fact that researchers have subjectively divided a space in the house into convex spaces as units for Space Syntax analysis. Therefore, this study aims to develop an objective and rational spatial subdivision technique for Space Syntax analysis of a Korean traditional house modelled by using BIM. We could objectively and reasonably divide a Korean traditional house space into convex spaces by recognizing the building components in the house modelled in the form of Industry Foundation Classes(IFC). Depending on the connection of convex spaces allocated in the spatial subdivision technique, j-graph in Space Syntax could be drawn and the measurements of spatial configurations could be determinded. Through the developed technique, the social properties including the cultural and philosophical aspects of Korean people was identified by measuring the spatial configurations of Korean traditional house. The developed technique will serve as useful means to help architects to find an appropriate purpose of each space for sustainable architecture on the basis of the spatial and social relationships in buildings or urban systems.

Multiresolution Mesh Editing based on the Extended Convex Combination Parameterization (확장 볼록 조합 매개변수화 기반의 다중해상도 메쉬 편집)

  • 신복숙;김형석;김하진
    • Journal of Korea Multimedia Society
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    • v.6 no.7
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    • pp.1302-1311
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    • 2003
  • This paper presents a more stable method of multiresolution editing for a triangular mesh. The basic idea of our paper is to embed an editing area of a mesh onto a 2D region and to produce 3D surfaces which interpolate the editing-information. In this paper, we adopt the extended convex combination approach based on the shape-preserving parameterization for the embedding, which guarantees no self-intersection on the 2D embedded mesh. That is, the result of the embedding is stable. Moreover, we adopt the multi-level B-spline approach to generate the surface containing all of 3D editing-information, which can make us control the editing area in several levels. Hence, this method supports interactive editing and thus can produce intuitive editing results.

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3D Spatial Information Acquisition for Construction Operation and Maintenance on a Construction Site (효율적인 건설공사와 유지관리를 위한 건설현장에서의 3차원 공간 정보 획득)

  • Kim, Chang-Wan
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • 2004.11a
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    • pp.188-193
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    • 2004
  • 3D spatial-modeling can be used in various safety-enhancement applications and for as-built data acquisition in project-control systems. The objective of the research reported herein was to provide spatial-modeling methods that represent construction sites in an efficient manner and to validate the proposed methods by testing them in an actual construction environment. Algorithms to construct construction-site scenes and to carry out coordinate transformations in order to merge data from different acquisition locations are presented. Field experiments were conducted to establish performance parameters and validation for the proposed methods and models. Initial experimental work has demonstrated the feasibility of this approach.

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A Photogrammetric Approach to Create 3-Dimensional Models of Irregular-shaped Curves (부정형 곡선의 3차원 모델 제작에 대한 사진측량적 접근)

  • Chang, Ji Hong
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.10 no.6
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    • pp.545-551
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    • 2017
  • It is very important to effectively obtain the information related to the human body shape for user-centered design. The human body shape is a huge combination of various irregular curves and is typically obtained by a 3-D Scanner. 3-D scanners show high reliability; however, they are expnsive equipment with limited mobility. 3-D models of irregular-shaped curves were created by a photogrammetric approach and the errors between the original curve and the models were evaluated. 3-D models were created based on 160, 80, 40, 20, 10, and 5 marking points evenly located on the original curve. In the case of convex curve, low levels of residuals were observed in the models from 160, 80, 40, and 20 marking points (0.13% max). In the combination of convex and concave curves, relatively low levels of residuals were observed in the models from 160, 80, and 40 marking points (0.29%). It is possible to conclude that marking points should be placed at every 5% of overall length of a convex curve and at every 2.5% of overall length of a curve with convex and concave curve in order to maintain low levels of errors. A photogrammetric approach can be used as an alternative for the 3-D scanners with advantages of low cost and mobility.

Video-Dissolve Detection using Characteristics of Neighboring Scenes (이웃 장면들의 특성을 이용한 비디오 디졸브 검출)

  • 원종운;최재각;박철현;김범수;곽동민;오상근;박길흠
    • Journal of KIISE:Information Networking
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    • v.30 no.4
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    • pp.504-512
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    • 2003
  • In this paper, we propose a new adaptive dissolve detection method based on the analysis of a dissolve modeling error which is the difference between an ideally modeled dissolve curve with no correlation and an actual dissolve curve including a correlation. The proposed dissolve detection method consists of two steps. First, candidate dissolve regions are extracted using the characteristics of a downward convex parabola, then each candidate region is verified based oil the dissolve modeling error. If the dissolve modeling error for a candidate region is less than a threshold defined by the target modeling error with a target correlation, the candidate region is determined as a resolve region with a lower correlation than the target correlation. The threshold is adaptively determined based on the variances between the candidate regions and the target correlation. By considering the correlation between neighbor scenes, the proposed method is able to be a semantic scene-change detector. The proposed method was tested on various types of data and its performance proved to be more accurate and reliable regardless of variation of variance of test sequences when compared with other commonly use methods.