• Title/Summary/Keyword: time like

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A K-means-like Algorithm for K-medoids Clustering

  • Lee, Jong-Seok;Park, Hae-Sang;Jun, Chi-Hyeok
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2005.10a
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    • pp.51-54
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    • 2005
  • Clustering analysis is a descriptive task that seeks to identify homogeneous groups of objects based on the values of their attributes. In this paper we propose a new algorithm for K-medoids clustering which runs like the K-means algorithm. The new algorithm calculates distance matrix once and uses it for finding new medoids at every iterative step. We evaluate the proposed method using real and synthetic data and compare with the results of other algorithms. The proposed algorithm takes reduced time in computation and better performance than others.

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A Numerical Study on Pyrolysis of Trichloroethane for Reactor geometry design (TCE 열분해 반응기의 형상 설계를 위한 수치해석적 연구)

  • La, Seung-Hyuck;Kang, Kyung-Tae;Kim, Sang-Young;Hwang, Jung-Ho
    • 한국연소학회:학술대회논문집
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    • 2002.06a
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    • pp.106-110
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    • 2002
  • Trichlorethane (TCE) is known as one of major carcinogens. TCE is difficult to be incinerated environmentally friendly, so pyrolysis is suggested for TCE treatment. In this study, we examined effects of cylinder-type pyrolysis reactor design parameters like existence of baffle inside reactor and reactor operating condition like heating reactor wall temperature and residence time numerically using CFX 4.3, a commercial computational fluid dynamic program.

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A Study on D-Optimal Design Using the Genetic Algorithm

  • Yum, Joon-Keun
    • Communications for Statistical Applications and Methods
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    • v.7 no.1
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    • pp.357-370
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    • 2000
  • This study has adapted a genetic algorithm for an optimal design for the first time. the models that was used a simulation are the first and second order response surfaces model, Using an genetic algorithm in D-opimal it is more efficient than previous algorithms to get an object function. Not like other algorithm without any restrictions like troublesome about the initial solution not falling into a local optimal solution it's the most suitable algorithm.

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SURFACES WITH CONSTANT GAUSSIAN AND MEAN CURVATURES N THE ANTI-DE SITTER SPACE ℍ31

  • Ugur Dursun
    • Honam Mathematical Journal
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    • v.46 no.2
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    • pp.249-266
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    • 2024
  • In this work, we study time-like and space-like surfaces invariant by a group of translation isometries of the half-space model ℋ31 of the anti-de Sitter space ℍ31 . We determine all such surfaces with constant mean curvature and constant Gaussian curvature. We also obtain umbilical surfaces of ℋ31.

Vibrational enhancement of evolutionary monochromatic neutron transport

  • Nassar H.S. Haidar
    • Nuclear Engineering and Technology
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    • v.56 no.7
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    • pp.2563-2569
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    • 2024
  • The monochromatic hyperbolic neutron density wave is conceived as a Rayleigh-like wave with mixed transverse and longitudinal components. It is proved for the first time that the absolute ratio of the longitudinal to transverse interfering components, varies, with increasing the frequency of this wave, from zero to 1. Such a limited variation is to be coined as vibrational enhancement of evolutionary one-speed neutron transport.

A Real-Time Collision-Free Trajectory Planning and Control for a Car-Like Mobile Robot (이동 로봇을 위한 실시간 충돌 회피 궤적 계획과 제어)

  • 이수영;이석한;홍예선
    • Journal of Institute of Control, Robotics and Systems
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    • v.5 no.1
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    • pp.105-114
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    • 1999
  • By using the conceptual impedance and the elasticity of a serial chain of spring-damper system, a real-time collision-free trajectory generation algorithm is proposed. The reference points on a trajectory connected by the spring-damper system have a mechanism for self-Position adjustment to avoid a collision by the impedance, and the local adjustment of each reference point is propagated through the elasticity to a real robot at the end of the spring-damper system. As a result, the overall trajectory consisting of the reference points becomes free of collision with environmental obstacles and efficient having the shortest distance as possible. In this process, the reference points connected by the spring-damper system take role of virtual robot as global guidance for a real robot, and a cooperative optimization is carried out by the system of virtual robots. A control algorithm is proposed to implement the impedance for a car-like mobile robot.

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An Implementation of YK2 Cipher System for Electronic Commerce Security (전자상거래 보안을 위한 YK2 암호시스템의 구현)

  • 서장원
    • The Journal of Society for e-Business Studies
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    • v.6 no.1
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    • pp.17-33
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    • 2001
  • EC(Electronic Commerce) which is done on the virtual space through Internet has strong point like independence from time and space. On the contrary, it also has weak point like security problem because anybody can access easily to the system due to open network attribute of Internet, Therefore, we need the solutions that protect the EC security problem for safe and useful EC activity. One of these solutions is the implementation of strong cipher system. YK2(Young Ku King) cipher system proposed in this paper is good solution for the EC security and it overcome the limit of current block cipher system using 128 bits key length for input, output, encryption key and 32 rounds. Moreover, it is designed for the increase of time complexity by adapting more complex design for key scheduling algorithm regarded as one of important element effected to encryption.

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Development of the real-time Imaging Processing Board Using FPGA (FPGA를 이용한 고속 영상처리보드의 개발)

  • 류형규;박홍민
    • Proceedings of the IEEK Conference
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    • 1998.10a
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    • pp.449-452
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    • 1998
  • In this study, the basic image-board and algorithm has been developed to extract a road lane by modeling the driving process. The high speed processing enables an image capture, processing and prompt decision making. In order to high speed processing ASIC like FPGA was designed and integrated in one board system. The algorithm enabling road driving must recognize a straight and bend edge separately. The high speed image processing board using FPGA can be used in real-time decision makeing system for road driving and in the machine vision under bad working environments like a coal mine. And it also can be used in the safety control system in subway and in image input system of CCTV and CATV by designing the board to meet various user's needs.

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The fashion Design of the Avantgarde Artists during the Early Twentieth Century - Focus on the Constructivism - (20세기 초반 러시아 아방가르드 미술가의 의상디자인 활동 - 구성주의를 중심으로 -)

  • 오선희
    • Journal of the Korean Society of Costume
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    • v.51 no.3
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    • pp.59-73
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    • 2001
  • This paper is to examine the meaning of activities of a number of artists who belong to Constructivism in the fashion design area during early twentieth century. After Russian Revolution, the artists like Nadeshda Lamanowa, Ljubow Popowa and Warwara Stepanova decided to devote to practical art area for many People. It's very meaningful for them to jump into real work places like a textile mill and a clothing workshop instead of staying in fine art area. Constructivism is more related to social interest rather than individual thing. The artists tried to apply their modeling principles in fine art to dress making. We can see the geometrical lines and shapes and big differences In colors and material in their dress. The artists had also shown personal tastes to dress works. This idea of togetherness with their time and even to create the style of it. was very renovative at that time and gave an influence on the later styles.

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