• Title/Summary/Keyword: An Chung Hwan

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An adaptive streaming client based on MPEG-21 multimedia framework (MPEG-21 멀티미디어 프레임워크에 기반한 적응형 비디오 전송 단말)

  • Oh, Hwa-Yong;Kim, Dong-Hwan;Chang, Tae-Gyu
    • Proceedings of the KIEE Conference
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    • 2006.07d
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    • pp.2120-2121
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    • 2006
  • 본 논문에서는 네트워크 상태, 사용자 단말 성능, 지원 가능한 비디오 포맷등 사용자 정보들을 서버와 공유하여 원활한 비디오스트리밍이 가능한 클라이언트를 기술한다. 이러한 사용자 정보는 MPEG-21 멀티미디어 프레임워크를 이용하여 서버와 통신하며, 기존의 VoD의 단방향 스트리밍이 아닌 양방향의 스트리밍 구조로 설계하였다. 양방향 스트리밍은 사용자 환경뿐만 아니라 이전에 재생된 비디오 시퀀스 및 사용자 이동성에 따른 적응형 재생이 가능하도록 스트리밍과 다른 통신채널을 이용하여 단말의 정보를 서버에게 보낼 수 있다. 실제 응용과 검증을 위해 본 논문에서는 PC를 이용한 단말 시스템과 PDA를 이용하여 동작시험 결과를 얻었다.

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Development of Image-Based Modeller Using Primitive Constraints

  • Seo, Sang-Hyun;Kim, Dong-Hwan;Yoon, Kyung-Hyun
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.164.3-164
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    • 2001
  • In this paper, we present a method for obtaining the actual modeling data through reconstructing a 3D data from an image and a method of estimating the geometrical information and the camera location of architectural objects from a photograph containing a virtual environment are introduced. Our approach combines both geometry-based and image-based modeling techniques. The modeling system is effective and robust because it exploits constrains that are characteristic of architectural scenes. Our approach can recover models for use in either geometry-based rendering systems. We present results that demonstrate out approach´s ability to create realistic renderings of architectural scenes from viewpoints far from the original photographs.

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Optimal Design of DC motor using Mixed Algorithm (Mixed Algorithm 개발과 이를 이용한 직류 모터의 최적설계)

  • Oh, Yong-Hwan;Chung, Tae-Kyung;Kim, Min-Kyu
    • Proceedings of the KIEE Conference
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    • 1998.07a
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    • pp.70-72
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    • 1998
  • This paper discusses the development of a new optimization algorithm for DC motor design. In principle, the new algorithm utilizes a mixed method that consists of genetic algorithms in conjunction with direct search method. The genetic algorithms are used for locating the global optimum region while the direct search method is used to achieve objective function convergence. In order to validate the effectiveness, the new algorithm has been applied to an actual DC motor. Field and torque characteristics of the DC motor are computed using finite element method and the principle of virtual work, respectively.

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A Study on the Output Noise Reduction of 3-Phase Multilevel Inverter (3상 멀티레벨 인버터 출력노이즈 저감에 관한 연구)

  • Kim, Soo-Hong;Jin, Kang-Hwan;Kin, Yoon-Ho
    • Proceedings of the KIPE Conference
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    • 2007.07a
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    • pp.101-103
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    • 2007
  • Since they use the low switching frequency in multilevel inverter systems, they generate the high low frequency harmonic components. Generally, LC filter is used at the output terminal of inverter systems to solve this problem. But it causes a voltage drop at the output terminal by use of damping resistors, and causes the problem in which system efficiency decreases due to power loss of the damping resistor. In this paper, we proposed an output filter design method for NPC three-level inverter systems with low switching frequency. And we analyzed the efficiency of the proposed filter system, and the effectiveness of the proposed system is verified by simulation and experimental results.

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Understanding Temporal Change of Centrality by Analyzing Social Network among Korean actors (한국 영화배우 소셜 네트워크 데이터 분석을 통한 중심성 변화 연구)

  • Choi, Joonyoung;Lee, O-Jun;Jung, Jason J.;Yong, Hwan-Sung
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2019.05a
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    • pp.37-40
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    • 2019
  • On this paper, we show the way of forming graph data structure via setting an edge between Korean actors if they appeared in the same movie. From this graph, we calculate the 'centralities' (which declared on this paper) for each actor, then examine distribution by ranking the actors of the centralities and analyze the change of the actor who is/was center on the graph by years. Finally, we suggest the way that sets the numerically Range limits on social group.

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The Effects of a Mineral Supplement (Aquamin $F^{(R)}$) and Its Combination with Multi-Species Lactic Acid Bacteria (LAB) on Bone Accretion in an Ovariectomized Rat Model

  • Lee, Hyun-Gi;Lee, Tae-Hee;Kim, Jung-Ha;Seok, Ju-Won;Lee, Seung-Hoon;Kim, Yong-Hwan;Kim, Jin-Eung;Chung, Myung-Jun;Yeo, Moon-Hwan
    • Biomedical Science Letters
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    • v.16 no.4
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    • pp.213-220
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    • 2010
  • Although an adequete intake of calcium (Ca) is recommended for the treatment and prevention of osteoporosis, the intake of Ca should be restricted because of its low rate of intestinal absorption. The purpose of this experiment was to identity the effect of the combined administration of Aquamin F (AQF) (a calcium agent) and lactic acid bacteria (LAB) on osteoporosis. Thirty ovariectomized (OVX) rats and six control rats were assigned to the following six groups, with six animals per group: sham Ca-deficient diet (Ca-D), OVX, LAB, AQF, and LAB-AQF. During the experiment, the body weight was measured; and after the experiment was completed, the serum biochemical analysis, the alkaline phosphatase, calcium, and inorganic phosphorus leves were measured. The tissue of the femur was stained and then scanned via CT. The body weight of the OVX group increased more significantly than that of the control group. The results of the bone mineral content (BMC), Bone mineral density (BMD), serum biochemical analysis and histological test on the femur epiphysis showed no difference between the OVX group and the LAB group, whereas the results of the AQF group were more significant than those of the OVX group. In particular, the LAB+AQF group showed more significant increases in the aforementioned results than the AQF group. This experiment showed that the combined administration of AQF and LAB in ovariectomized rats more significantly increased bone density than did a single administration of either AQF or LAB.

A Study on General Structured Observer (일반 구조형 관측기에 관한 연구)

  • Lee, Chung-Hwan;Kim, Hwan-Seong;Kim, Sang-Bong
    • Journal of the Korean Society for Precision Engineering
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    • v.17 no.9
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    • pp.95-101
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    • 2000
  • This paper proposes a general structure observer and shows the characteristic of external noise reduction in linear discrete system. First we propose a simple genera structured observer which includes high gain term or PI(proportional integral) term to eatimate the states of system and show that the observer can estimate the states of system even if an external noise is added to the system's output. An existence condition of the observer is derived and checked by system's rank condition. Through a numerical example we can verify that the proposed observer is effective to estimate the state of system with external noise compared to that of conventional high gain observer.

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Integrated Method for Knowledge Discovery in Databases

  • Hong Chung;Park, Kyoung-Oak;Chung, Hwan-Mook
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1998.06a
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    • pp.122-127
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    • 1998
  • This paper suggests an integrated method for discovering knowledge from a large database. Our approach applies an attribute-oriented concept hierarchy ascension technique to extract generalized data from actural data in databases, induction of decision trees to measure the value of information, and knowledge reduction of rough set theory to remove dispensable attributes and attribute values. The integrated algorithm first reduce the size of database for the concept generalization, reduces the number of attributes by way of elimination condition attributes which have little influence on decision attribute, and finally induces simplified decision rules removing the dispensable attribute values by analyzing the dependency relationships among the attributes.

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An Efficient Multicast Routing Algorithm for Packet-Switched Networks

  • Chung, Sung-Jin;Hong, Sung-Pil;Park, Bum-Hwan
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 1998.10a
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    • pp.397-400
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    • 1998
  • This paper has a dual purpose. First, we consider a relaxation algorithm which seems to be particularly suitable for multicasting routing problems. We show that the algorithm has polynomial complexity. Second, to measure the quality of solutions in comparison to the optimal solutions over a wide range of network sizes for which the computation of the optimal costs is too excessive, we also propose a random graph generation scheme in which an asymptotic lower bound on the expected optimal cost can be computed as a function of network node size.

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Duodenal Perforation Caused by an Inferior Vena Cava Filter

  • Bae, Mi-Ju;Chung, Sung-Woon;Lee, Chung-Won;Kim, Sang-Pil;Song, Seung-Hwan
    • Journal of Chest Surgery
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    • v.45 no.1
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    • pp.69-71
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    • 2012
  • The inferior vena cava (IVC) filter is known as an effective and safe method for preventing fatal pulmonary thromboembolism in patients with deep vein thrombosis. Usually, the remaining IVC filters are asymptomatic and do not cause clinical problems. We report a case of duodenal perforation caused by a remaining IVC filter.