• Title/Summary/Keyword: Co-works

Search Result 667, Processing Time 0.029 seconds

Schema Analysis on Co-Evolutionary Algorithm (공진화에 있어서 스키마 해석)

  • Byung, Jun-Hyo;Sim, Kwee-Bo
    • Proceedings of the Korean Institute of Intelligent Systems Conference
    • /
    • 1998.03a
    • /
    • pp.77-80
    • /
    • 1998

  • The theoretical foundations of simple genetic algorithm(SGA) are the Schema Theorem and the Building Block Hypothesis. Although SGA does well in many applications as an optimization method, still it does not guarantee the convergence of a global optimum in GA-hard problems and deceptive problems. Therefore as an alternative scheme, there is a growing interest in a co-evolutionary system, where two populations constantly interact and cooperate each other. In this paper we show why the co-evolutionary algorithm works better than SGA in terms of an extended schema theorem. Also the experimental results show a co-evolutionary algorithm works well in optimization problems.

  • PDF

3D imaging of fracture aperture density distribution for the design and assessment of grouting works (절리 암반내 그라우팅 설계 및 성과 판단을 위한 절리틈새 밀도 분포의 3차원 영상화 연구)

  • Kim, Jung-Yul;Kim, Yoo-Sung;Nam, Ji-Yeon
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • 2004.03b
    • /
    • pp.113-120
    • /
    • 2004

  • Grouting works in fractured rocks have been performed to reinforce the underground and/or to block ground water flow at the foundation site of dam, bridge and so on. For the efficient grouting design, a prior knowledge of the fracture pattern of underground area to be grouted in very important. For the practical use, aperture sizes of open fractures that will be filled up with grouting materials will be kind of valuable information. Thus, the main purpose of this study is to develop a new technique (so called "GenFT") enable to form a three dimensional image of fracture aperture density distribution from Televiewer data. For this, the study is to focus on dealing with (1) estimating aperture size of each fracture automatically from Televiewer time image, (2) mapping extension of fracture planes on a given section, (3) evaluating aperture density distribution on the section by using both aperture size and fracture face mapping result of each fracture, (4) developing an algorithm that can transfer the previous results to any arbitrary(vertical and/or horizontal) section around the borehole. Since 3D imaging means "a strategy used to form an image of arbitrarily subdivided 2D sections with aperture density distribution", it will help avoid ambiguities of fracture pattern interpretation and hence will be of practical use not only for the design and assessment of grouting works but also for various engineering works. Examples of fields experiments are illustrated. It would seem that this technique might lead to reflecting future trend in underground survey.

  • PDF

A Design of digital PWM controller for automotive brake solenoid valve (자동차 제동 솔레노이드 밸브용 디지털 PWM 컨트롤러 설계)

  • Kim, Dong-hyeon;Shin, Changsik;Seo, Jin-ho;Shin, Kyung-wook
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
    • /
    • 2014.05a
    • /
    • pp.152-155
    • /
    • 2014

  • This paper describes a design of digital PWM controller for automotive brake solenoid valve which is used in ABS/ESC SoC. The PWM controller which consists of 12 channels supports both direct control and PI control. Six channels in direct control mode make consistent PWM signals according to duty ratio setting, and the others in PI control mode make PWM signals with constant current depending on current setting. The PWM controller also has functions including solenoid valve open detection, Dither and PWM phase shift. The PWM controller having 44,779 gates is fabricated using a 0.18um CMOS process, and test results show that all the functions are correct.

  • PDF