• 제목/요약/키워드: front tracking

검색결과 146건 처리시간 0.029초

PROPAGATION OF PHASE BOUNDARIES: EXISTENCE AND ADMISSIBILITY OF SOLUTIONS VIA FRONT TRACKING METHOD

  • Ahn, Hyeung-Won;Lee, Choon-Ho
    • Journal of applied mathematics & informatics
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    • 제20권1_2호
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    • pp.491-511
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    • 2006
  • The existence of the admissible solution for conservation laws of trilinear type occurring material sciences was proved by Abeyaratne and Knowles. LeFloch proved the existence of admissible solutions of conservation laws of this type via Glimm's method. In this paper we introduce a front tracking solution and prove the existence of the front tracking solution. We also investigate the admissibility of solutions via the Front Tracking Method.

바이모달 트램 곡선 선회폭에 관한 연구 (A Study on the Swept Path Width for the Bimodal Tram)

  • 문경호;장세기;목재균
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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    • pp.51-56
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    • 2011
  • The train travels on the track and, thus, the rear wheels precisely follow the paths of the front wheels. On the contrary, in the vehicles running on the road like automobiles, buses and trucks, the front wheels try to drag the rear ones toward them and across the inside of the curve. Off-tracking is defined as the radial offset between the path of the centerline of the front axle and the path of the centerline of the following axle. In the case of the bimodal tram with AWS(all wheel steering), the off-tracking decrease but the rear swing-out values increase because of the rear steering at the reverse phase angle. Thus, in order to determine the swept path width, maximum road width at the minimum turning radius, off-tracking and swing-out should be considered for the bimodal tram. In this paper, trajectory simulations were carried out for the various condition such as front steering, front and rear steering and suppression of swing-out to optimize the swept path width.

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Front Points Tracking in the Region of Interest with Neural Network in Electrical Impedance Tomography

  • Seo, K.H.;Jeon, H.J.;Kim, J.H.;Choi, B.Y.;Kim, M.C.;Kim, S.;Kim, K.Y.
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2003년도 ICCAS
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    • pp.118-121
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    • 2003
  • In the conventional boundary estimation in EIT (Electrical Impedance Tomography), the interface between anomalies and background is expressed in usual as Fourier series and the boundary is reconstructed by obtaining the Fourier coefficients. This paper proposes a method for the boundary estimation, where the boundary of anomaly is approximated as the interpolation of front points located discretely along the boundary and is imaged by tracking the points in the region of interest. In the solution to the inverse problem to estimate the front points, the multi-layer neural network is introduced. For the verification of the proposed method, numerical experiments are conducted and the results indicate a good performance.

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Laser와 열전대를 이용한 연기선단의 위치 추적 비교에 관한 연구 (The tracking of a smoke front under a ceiling by a laser sheet and thermocouples)

  • 김명배;한용식;윤명오;김진곤
    • 한국화재소방학회논문지
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    • 제12권3호
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    • pp.11-20
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    • 1998
  • 천장아래에 형성된 연기흐름을 대상으로 Laser 평면광과 열전대를 이용하여 연기선단의 위치를 추적하였다. 새로운 실험방법을 이용하여 연기선단의 도착순간을 열전대의 온도신호로부터 판단하는 종래의 직관적 기준을 평가하였다. 이러한 실험방법에서 사용된 Laser 평면광은 연기를 가시화 하기 위한 종래의 여러방법에 비교하여 뚜렷한 장점들이 있음을 입증하였다.

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ON THE NUMERICAL METHODS FOR DISCONTINUITIES AND INTERFACES

  • Hwang, Hyun-Cheol
    • 대한수학회논문집
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    • 제13권3호
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    • pp.655-681
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    • 1998
  • Discontinuous solutions or interfaces are common in nature, for examples, shock waves or material interfaces. However, their numerical computation is difficult by the feature of discontinuities. In this paper, we summarize the numerical approaches for discontinuities and interfaces appearing mostly in the system of hyperbolic conservation laws, and explain various numerical methods for them. We explain two numerical approaches to handle discontinuities in the solution: shock capturing and shock tracking, and illustrate their underlying algorithms and mathematical problems. The front tracking method is explained in details and the level set method is outlined briefly. The several applications of front tracking are illustrated, and the research issues in this field are discussed.

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Level Contour Reconstruction 방법을 이용한 다상유동 수치해석 (NUMERICAL SIMULATION OF MULTIPHASE FLOW USING LEVEL CONTOUR RECONSTRUCTION METHOD)

  • 신승원
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2009년 추계학술대회논문집
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    • pp.193-200
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    • 2009
  • Recently, there have been efforts to construct hybrids among the existing methodologies for multiphase flow such as VOF, Level Set, and Front Tracking with the intention of facilitating simulations of general three-dimensional problems. As one of the hybrid method, we have developed the Level Contour Reconstruction Method (LCRM) for general three-dimensional multiphase flows including phase change. The main idea was focused on simplicity and a robust algorithm especially for the three-dimensional case. It combines characteristics of both Front Tracking and Level Set methods. While retaining an explicitly tracked interface using interfacial elements, the calculation of a vector distance function plays a crucial role in the periodic reconstruction of the interface elements in the LCRM method to maintain excellent mass conservation and interface fidelity. In addition, compact curvature formulation is incorporated for the calculation of the surface tension force thereby reducing parasitic currents to a negligible level.

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Numerical Study of Ejected Droplet Formation in Two-Liquid System

  • Song, Mu-Seok;Shunji Homma;Haruhisa Honda
    • Journal of Ship and Ocean Technology
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    • 제7권4호
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    • pp.32-40
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    • 2003
  • Numerical simulation code is developed to study the formation of liquid drops from a nozzle into another quiescent liquid. The Navier-Stokes equations for two immiscible, incompressible, Newtonian fluids are solved on a fixed, staggered grid of cylindrical axisymmetric coordinates. Interfacial motion is captured using a Front-Tracking Method. The time variation of interfacial shape simulated by the code is in excellent agreement with experiments. Simulation results show that the viscosity ratio affects the size of the satellite drops.

Microsoft-Kinect 센서를 활용한 화자추적 시스템 (Microsoft-Kinect Sensor utilizing People Tracking System)

  • 반태학;이상원;김재민;정회경
    • 한국정보통신학회:학술대회논문집
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    • 한국정보통신학회 2015년도 춘계학술대회
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    • pp.611-613
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    • 2015
  • 멀티미디어 강의실에서는 자동 강의 저장뿐 아니라 카메라의 추적도 자동으로 추적하여 저장되도록 발전하고 있다. 기존의 추적 시스템은 별도의 센서를 몸에 부착하여 추적하거나 전면에 센서를 시공하여 추적하는 불편함이 있었고 동시에 여러명이 전면에 나타나면 에러가 발생하여 추적이 안된다거나 하는 문제점이 있었다. 본 논문에서는 Microsoft-Kinect 센서를 이용하여 화자(강사)의 위치 및 행동을 분석하며, 이를 PTZ 카메라 및 강의 저장 수업녹화 시스템과 연동하여 강의실 수업 녹화시에 효과적인 콘텐츠 생산을 가능하도록 하는 무인화자 추적 솔루션에 대하여 기술하였다.

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바지 맞음새 평가 시 전문가와 초보자의 시선추적 및 맞음새 평가 항목의 중요도 비교분석 - Eye Tracking 기법을 이용하여 - (Comparison of Eye Movement and Fit Rating Criteria in Judging Pants Fit Between Experts and Novices - Using Eye Tracking Technology -)

  • 김영숙;송화경;장효웅
    • 한국의류산업학회지
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    • 제19권2호
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    • pp.230-239
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    • 2017
  • In the clothes industry, there are lack of experts including technical designers who can analyze the fit of clothes. This study is to provide practical data available for fit analysis education by distinguishing the differences in standards and aspects of garment fit between experts and novices, through the eye-tracking technology to quantify the sense of fit. For this study, two groups were organized; one composed of 7 experts with over 15 year-experience including technical designers and patternmakers, and the other composed of 7 novices who are students majoring in clothing. Wearing the goggle type eye-tracker Tobii Pro Glasses 2, the participants in the experiments were required to conduct fit analyses for a pair of pants on a live model. After those experiments, they were required to check the items for fit analysis and assess the importance level of them on a questionnaire. The differences between the two groups in the ratios of total visit count and total visit duration by each AIO(Area of Interest) of clothes were analyzed through non-parametric statistical test. The results of eye tracking experiments showed that experts focused on center front and back line, crotch area, and side seam, while novice's fixation points were dispersed around the pants. The survey results showed that the experts put importance on the center line position and its verticality, front-back proportion of side seam line, and front-back proportion of waist line, 71.4~100% of whom checked them, while 14.3% of the novices checked them.

LabVIEW에 의한 Tracking 신호 분류 및 인식 (Classification and recognition of electrical tracking signal by means of LabVIEW)

  • 김대복;김정태;오성권
    • 전기학회논문지
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    • 제59권4호
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    • pp.779-787
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    • 2010
  • In this paper, We introduce electrical tracking generated from surface activity associated with flow of leakage current on insulator under wet and contaminated conditions and design electrical tracking pattern recognition system by using LabVIEW. We measure the leaking current of contaminated wire by using LabVIEW software and the NI-c-DAQ 9172 and NI-9239 hardware. As pattern recognition algorithm and optimization algorithm for electrical tracking system, neural networks, Radial Basis Function Neural Networks(RBFNNs) and particle swarm optimization are exploited. The designed electrical tracking recognition system consists of two parts such as the hardware part of electrical tracking generator, the NI-c-DAQ 9172 and NI-9239 hardware and the software part of LabVIEW block diagram, LabVIEW front panel and pattern recognition-related application software. The electrical tracking system decides whether electrical tracking generate or not on electrical wire.