• Title/Summary/Keyword: 경계 특성

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Seismic Response Analysis of a Floating Bridge with Discrete Pontoons (이산폰툰형 부유식교량의 지진응답해석)

  • Kwon, Jang-Sup
    • Journal of the Earthquake Engineering Society of Korea
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    • v.9 no.2 s.42
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    • pp.47-58
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    • 2005
  • Dynamic response analysis in time dimain is conducted for floating bridges with discrete pontoons subject to spatial variation of ground motions. The Spatial variation of ground motions is considered with the coherency function model which represents wave passage, incoherence and local site effects. The superstructure of the bridge is represented by space frame and elastic catenary cable elements, the abutment us modelde with the spring element of FHWA guideline for considering soil structure interaction and the concept of retardation function is utilized to consider the frequency dependency of the hydrodynamic coefficients which are obtainde by boundary element method. multiple support excitations considering the spatial variation. The noticeable amplification of the response can be shown when the spatial variation of ground motions is incorporated in the anallysis of floating bridges.

Automatic Generation of the Personal 3D Face Model (3차원 개인 얼굴 모델 자동 생성)

  • Ham, Sang-Jin;Kim, Hyoung-Gon
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.36S no.1
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    • pp.104-114
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    • 1999
  • This paper proposes an efficient method for the automatic generation of personalized 3D face model from color image sequence. To detect a robust facial region in a complex background, moving color detection technique based on he facial color distribution has been suggested. Color distribution and edge position information in the detected face region are used to extract the exact 31 facial feature points of the facial description parameter(FDP) proposed by MPEG-4 SNHC(Synthetic-Natural Hybrid Coding) adhoc group. Extracted feature points are then applied to the corresponding vertex points of the 3D generic face model composed of 1038 triangular mesh points. The personalized 3D face model can be generated automatically in less then 2 seconds on Pentium PC.

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Multi-States Based Hybrid Location Update Strategy in Wireless Communication System (이동 통신망에서의 다중 상태 기반의 혼합형 위치 갱신 방법)

  • Lee, Goo-Yeon;Lee, Yong
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.44 no.1
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    • pp.113-122
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    • 2007
  • In this paper, we propose a multi-state based hybrid location update scheme, which integrates the time-based and the movement-based methods. In the proposed scheme, a mobile terminal updates its location after n cell boundary crossing and a time interval of T[sec]. We derive an analytical solution for the performance of the hybrid scheme with exponential cell resident time and evaluate it numerically with time-varying random walk mobility model, which we model as multi-states Markov chain. Furthermore, we also evaluate the scheme for arbitrary cell resident times by simulation. From the numerical analysis and the simulation results, we prove that the proposed scheme significantly outperforms the time-based and the movement-based methods, when implemented alone, more accurately adapting to the time-varying user mobility.

Seismic performance evaluation of Pier-Shafts system with multi-layered soil (다양한 지반층을 갖는 Pier-Shafts 시스템의 내진성능평가)

  • Jang, Sung-Hwan;Nam, Sang-Hyeok;Song, Ha-Won;Kim, Byung-Chul
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.04a
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    • pp.69-72
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    • 2008
  • The so-called Pier-Shafts system which consists of the continuous column and shaft is often used to support the highway bridge structure because of advantages in easy construction and low cost. In the earthquake region, the Pier-Shafts system undergoes large displacements and represents a nonlinear behavior under the lateral seismic loading. The soil-pile interaction should be considered for more accurate analysis of the Pier-Shafts system. In this study, a transverse response of a reinforced concrete Pier-Shafts system inside multi-layered soil medium is predicted using a finite element program which adopts an elasto-plastic interface model for the interface behavior between the shaft and the soil. Then, seismic analysis is performed to evaluate the performance of Pier-Shafts system under strong ground motion and their results are verified with experimental data.

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Analysis of Crack Width and Deflection Based on Nonlinear Bond Characteristics in Reinforced Concrete Flexural Members (비선형 부착 특성에 기반한 철근콘크리트 휨부재의 균열폭과 처짐 해석)

  • Lee, Gi-Yeol;Kim, Woo
    • Journal of the Korea Concrete Institute
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    • v.20 no.4
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    • pp.459-467
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    • 2008
  • This paper describes a proposal for average crack width and immediate deflection calculation in structural concrete members. The model is mathematically derived from actual bond stressslip relationships and tension stiffening effect between reinforcement and the surrounding concrete, and the actual strains of steel and concrete are integrated respectively along the embedded length between the adjacent cracks so as to obtain the difference in the axial elongation. With these, a model for average crack width and immediate deflection in reinforced concrete flexural members are proposed utilizing difference in the axial elongation and average steel strain and moment-curvature relationship with taking account of bond characteristics. The model is applied to the test specimens available in literatures, and the crack width and deflections predicted by the proposal equation in this study are closed to the experimentally measured data compared the current code provisions.

A Phenomenological Approach to Traumatic Experiences Among North Korean Defectors (북한이탈주민의 남한이주 과정의 외상적 체험에 대한 현상학적 연구)

  • Eom, Tae-Wan
    • Korean Journal of Social Welfare
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    • v.61 no.2
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    • pp.189-213
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    • 2009
  • This study aimed to understand the meaning and essence of trauma accidents that North Korean Defectors experienced while escaping from North Korea. We approached with phenomenological method, and the study targets were 7 North Korean Defectors who underwent trauma such as torture, fear, violence, starvation and disease in the course of escaping from North Korea. As a result, we found that the trauma of participants is linked to the present after years while categorizing 6 theme clusters into 'struggle in the border of life and death', and 'difference between being left alive and living'. The image and memory imprinted in the mind of participants from the trauma accident has continued for years and is related with their daily life in South Korea. In this study, we could realize that some elements which had been thought to be negative features of North Korean Defectors are unavoidable extraordinary nature of people who experienced trauma.

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Improved Control Algorithm Development for Control Element Drive Mechanism Control System (제어봉구동장치제어계통의 개선된 제어 알고리즘 개발)

  • Kim, Byeong-Moon;Lee, Young-Ryul;Han, Jae-Bok;You, Joon
    • Proceedings of the KIEE Conference
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    • 1995.07b
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    • pp.761-765
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    • 1995
  • The old Timing Controller for Control Element Drive Mechanism (CEDM) is designed as an open loop control system because it is difficult to mount sensors within the Control Element Drive Mechanism(CEDM) which is operating under the pressure boundary of the reactor vessel. In this work new method which can be used to detect the CEDM operational conditions without mounting sensors within the CEDM housing is developed in order to resolve problems of the old Timing Controller. By using the developed new method, the new Timing Controller for the CEDM is designed as a closed loop controller which has features of the control rod drop prevention, fine position control and the coil life time extension. The algorithm developed under closed loop control concept resolves most problems occurred in the old Timing Controller and improves the performance and reliability of the system. During designing and testing of the Timing Controller algorithm, the real time CEDM simulator developed here was used. And all functions of the developed algorithm were verified using CEDM simulator with the real data collected from the site. The results show that the Timing Controller performs its intended functions properly.

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A Case study of Knowledge & Information Contents applied Gamification and Alternate Reality Game concepts (게이미피케이션과 대체현실게임 개념을 적용한 지식정보콘텐츠 사례 연구)

  • Shin, Dong-Hee;Kim, Hee-Kyung
    • Journal of Digital Contents Society
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    • v.14 no.2
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    • pp.151-159
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    • 2013
  • Recently, gamification has garnered high attention in various fields outside the traditional game world through the adoption of game techniques. The introduction of gamification creates an alternate reality game. It appears virtually the same as other normal games, but is able to pull down the boundary between reality and imagination. At first, this was utilized by the entertainment industry for movies, advertisements, and drama publicity. We can see examples of gamification extending into the knowledge and information contents field. The purpose of knowledge and information contents is to pursue meaning and utility rather than fun, though the introduction of game methods remains interesting. In-depth examination of the conception of an alternate reality game via gamification will lead to the understanding of progression and quality of alternate reality games in the context of knowledge and information contents. As a result, we can effectively understand not only the immediate uses but also be able to measure the potential for utilization of gamification for various fields.

Numerical Study on Mode Transition in a Scramjet Engine (스크램제트 엔진에서의 모드 천이에 관한 수치해석 연구)

  • Ha, Jeong Ho;Das, Rajarshi;Ladeinde, Foluso;Kim, Tae Ho;Kim, Heuy Dong
    • Journal of the Korean Society of Propulsion Engineers
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    • v.21 no.6
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    • pp.21-31
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    • 2017
  • In the present study, theoretical and numerical analyses have been carried out to investigate the detailed flow characteristics during the mode transition. The theoretical analysis rearranged the knowledge of gasdynamics and the previous studies, and the numerical analysis has conducted to solve the 2D unsteady compressible Navier-Stokes equations with a fully implicit finite volume scheme. To validate the numerical analysis, the experiment was compared with it. The total temperature at the inlet of isolator and the hydrogen fuel equivalent ratio were changed to investigate their effects on the mode transition phenomenon. As the results, the numerical analysis reproduced well the experiment qualitatively, the increment in the hydrogen fuel equivalent ratio induced the scram-mode to ram-mode transition which is discontinuous with a non-allowable region, and the variation in the total temperature changed the boundary of the mode transition.

MR Images and $^1H$ MR Spectroscopy of Enteric Duplication Cyst of the Pancreas in an Adult (췌장 중복낭의 자기공명영상 소견과 수소자기공명분광법: 증례 보고)

  • Park, Sung-Hee;Kim, Mi-Young;Suh, Chang-Hae;Lee, Keon-Young;Choi, Suk-Jin;Cho, Jae-Young
    • Investigative Magnetic Resonance Imaging
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    • v.14 no.2
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    • pp.139-144
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    • 2010
  • Enteric duplications associated with the pancreas are especially uncommon, and the differential diagnosis of pancreatic duplication cysts is often difficult, and may be confused with various cystic lesions of the pancreas. We report a case of pancreatic duplication cyst; present the images and laboratory findings including cyst fluid tumor markers. MR and MRS findings enabled the detection of the location, contour, characteristics of cystic fluid and definition of tissue planes between the lesion and adjacent structures, providing useful information for an accurate surgical approach.