• Title/Summary/Keyword: Resizing Algorithm

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A Study on the design Optimization of Thickness of Machiningcenter Bed under Dynamic Loading by using Genetic Algorithm (유전적 알고리듬을 적용하여 머시닝센터 베드두께의 동하중을 고려한 최적설계에 관한 연구)

  • 조백희
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.8 no.1
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    • pp.67-73
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    • 1999
  • This paper presents resizing design optimization method by utilizing genetic algorithm(GA), which consists of three basic operators : reproduction, crossover and mutation. The fitness and penalty function for resizing optimization problem are defined, and the flowchart of the developed computer program along with the descriptions of each modules is presented. Also, modelling for flexible-body dynamic analysis is presented. The model is composed of bodies, joints, and force elements such as translational spring-damper-actuator. The design objects si to determine the wall thickness for minimum weight under dynamic displacement constraint.

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Development of Drift Design Method of High-rise buildings considering Material Properties of Shear Walls and Design Variable Linking Strategy (RC 전단벽의 재료 물성과 부재 그룹핑을 고려한 고층건물 변위조절설계법 개발)

  • 서지현;박효선
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2004.04a
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    • pp.487-494
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    • 2004
  • Resizing techniques have been recognized as practical methods for drift design of high-rise building since sensitivity analysis and iterative structural analysis are not required in implementation. In the techniques, the amount of material of a memberin a building for resizing is determined in terms of cross-sectional areas and sectional inertia moments as design variables. In this study, five drift design methods are developed by considering design variable linking strategy and fomulating resizing algorithm in terms of material properties of shear walls as a design variable. The developed methods are applied to the drift design of 20-story frame-RC shear wall structure, and then evaluated in the view points of practicality and efficiency.

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Stiffness Design Method of Steel Structures using Resizing Techniques (재분배기법을 이용한 강구조물의 강성설계법)

  • Ahn, Sun A;Park, Hyo Seon
    • Journal of Korean Society of Steel Construction
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    • v.10 no.1 s.34
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    • pp.63-72
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    • 1998
  • The stiffness design method is presented as a drift control model of steel structures and applied to design of space trusses subjected to stress and displacement constraints. The stiffness design method is developed by integrating the resizing techniques for an effective drift control algorithm with the strength design process according to the commonly used design specifications such as allowable stress design. In the resizing technique the amount of material to be modified depends on the member displacement participation factors and is determined by an optimization technique. Using the stiffness design method, a structural design model for steel structures is proposed and applied to two verifying examples. As demonstrated in the examples, the displacement of the structures can be effectively controlled without expensive computational cost.

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SFMOG : Super Fast MOG Based Background Subtraction Algorithm (SFMOG : 초고속 MOG 기반 배경 제거 알고리즘)

  • Song, Seok-bin;Kim, Jin-Heon
    • Journal of IKEEE
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    • v.23 no.4
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    • pp.1415-1422
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    • 2019
  • Background subtraction is the major task of computer vision and image processing to detect changes in video. The best performing background subtraction is computationally expensive that cannot be used in real time in a typical computing environment. The proposed algorithm improves the background subtraction algorithm of the widely used MOG with the image resizing algorithm. The proposed image resizing algorithm is designed to drastically reduce the amount of computation and to utilize local information, which is robust against noise such as camera movement. Experimental results of the proposed algorithm have a classification capability that is close to the state of the art background subtraction method and the processing speed is more than 10 times faster.

Control Method of Wind Induced Vibration Level for High-rise buildings (초고층 건물의 풍가속도응답 조절 기법)

  • Kim Ji-Eun;Seo Ji-Hyun;Park Hyo-Seon
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2005.04a
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    • pp.375-382
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    • 2005
  • In this paper, a practical control method of wind-induced vibration of high-rise buildings is presented in the form of resizing algorithm. In the structural design process for high-rise buildings, the lateral load resisting system for the building is more often determined by serviceability design criteria including wind-induced vibration level. Even though many drift method have been developed in various forms, no practical design method for wind induced vibration has been developed so far. Structural engineers rely upon heuristic or experience in designing wind induced vibration. The performance of the proposed method is evaluated by comparing wind-induced vibration levels estimated both from approximate techniques and wind tunnel test.

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Adaptive Watermarking Using Wavelet Transform & Spread Spectrum Method (확산스펙트럼 방식과 웨이브렛 변환을 이용한 적응적인 워터마킹)

  • 김현환;김두영
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.4 no.2
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    • pp.389-395
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    • 2000
  • Digital Watermarking is a research area which aims at hiding secret information in digital multimedia content such as images, audio, and video. In this paper, we propose a new watermarking method with visually recognizable symbols into the digital images using wavelet transform, spread spectrum method and multilevel threshold value in considering the wavelet coefficients. The information of watermark can be extracted by subtracting wavelet coefficients with the original image and the watermarked image. The results of this experiment show that the proposed algorithm was superior to other similar watermarking algorithms. We showed Watermarking algorithm in JPEG lossy compression, resizing, LSB(Least Significant Bit) masking, and filtering.

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Topology Optimization Technique using Strain Energy Distributions induced by the Mode Shapes associated with Natural Frequencies (구조물의 자유진동모드로 유발되는 변형에너지 분포를 이용한 위상최적화기법)

  • Lee, Sang-Jin;Bae, Jung-Eun;Park, Gyeong-Im
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2006.05a
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    • pp.1015-1018
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    • 2006
  • In this paper, new topology optimization technique is proposed. It mainly uses the strain energy distributions induced by the mode shapes associated with natural frequencies of the structure and so we can implicitly consider the dynamic characteristics of the structure in the topology optimization process. The strain energy to be minimized is employed as the objective function and the initial volume of structures is adopted as the constraint function. The resizing algorithm devised from the optimality criteria method is used to update the hole size of the cell existing in each finite element. The cantilever beam problem is adopted to test the proposed techniques. From numerical test, it is found to be that the optimum topology of the cantilever produced by the proposed technique has a hugh increase of natural frequency value and the technique is very effective to maximize the fundamental frequency of the structure.

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Topology Optimization of Plane Structures with Multi-Frequency Cases (다진동수를 고려한 평면구조물의 위상최적화)

  • Lee, Sang-Jin;Bae, Jung-Eun;Park, Gyeong-Im
    • Proceeding of KASS Symposium
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    • 2006.05a
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    • pp.233-238
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    • 2006
  • This paper provides a new topology optimization technique which is intended to maximize the fundamental frequency with simultaneous consideration of other natural frequencies in the form of multi-frequency problems. The modal strain energy is considered as the objective function to be minimized and the initial volume of structures is used as the constraint function. The resizing algorithm based on the optimality criteria is adopted to update the hole size existing inside the material. From numerical tests, the proposed technique is found to be very effective to maximize the fundamental frequency of the structure and it can also successfully consider several higher mode effects into the optimum topology of structure through the introduction of weights.

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Low-Power Backlight Control and Its Acceleration Based on Image Resizing for Mobile LCD Displays (모바일 LCD 디스플레이의 저전력 Backlight 제어 및 영상 크기 조절을 이용한 가속화 기법)

  • Lee, Kyu-Ho;Bae, Jin-Gon;Kim, Jae-Woo;Kim, Jong-Ok
    • Journal of the Institute of Electronics and Information Engineers
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    • v.52 no.7
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    • pp.100-106
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    • 2015
  • In this paper, we propose a fast algorithm for low-power image enhancement method for mobile LCD. In the proposed fast algorithm, the spatial resolution of the input image is significantly reduced, and the image characteristics are analyzed on the reduced resolution image to find a dimming rate adaptive to the image content, thereby saving power. The proposed fast adaptive dimming and image enhancement algorithm is implemented as an application that runs on an Android device. Image quality evaluation and running time analysis experiments on the device indicate that the proposed fast algorithm jointly minimizes the quality degradation and power consumption, reducing the required computation load by over 95%.