• Title/Summary/Keyword: Boundary Similarity

Search Result 199, Processing Time 0.02 seconds

An Analytic Solution of the Shape of a Partially Filled, Submerged Membrane Container (수중 유체저장용 막구조물 형상의 이론적 해석)

  • Choi, Yoon-Rak
    • Journal of Ocean Engineering and Technology
    • /
    • v.22 no.5
    • /
    • pp.39-43
    • /
    • 2008
  • For a partially filled and deeply submersed membrane container, an analytic solution for similarity shape was studied. The static shape of a membrane container can be expressed as a set of nonlinear ordinary differential equations. These equations are combined into an integrable equation. The solution of the equation is derived in terms of elliptic integrals, the arguments of which contain an unknown at the point of inflection. The point of inflection is determined by using the boundary condition at a separating point. Some characteristic values of the similarity shape were evaluated and the shapes are illustrated.

Analytic Analysis of Liquid-Filled Membrane Container Resting on Horizontal Foundation with Given Cross-Sectional Volume (수평 지반에 놓인 액체 저장용 막구조물 형상의 단면 체적에 따른 해석적 해)

  • Choi, Yoon-Rak
    • Journal of Ocean Engineering and Technology
    • /
    • v.25 no.2
    • /
    • pp.62-66
    • /
    • 2011
  • In this paper, a liquid-filled long membrane container resting on a horizontal foundation is considered. All of the quantities are normalized to obtain similarity solutions. A system of nonlinear ordinary differential equations with undetermined boundary conditions is solved analytically. The integration of the curvature gives the solutions, which are expressed in terms of the elliptic integrals. A method for finding the shape and characteristic values is proposed for a given cross-sectional volume. The validity of these solutions is confirmed, and some results are shown for characteristic values and shapes.

Spatio-temporal video segmentation using a joint similarity measure (결합 유사성 척도를 이용한 시공간 영상 분할)

  • 최재각;이시웅;조순제;김성대
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.22 no.6
    • /
    • pp.1195-1209
    • /
    • 1997
  • This paper presents a new morphological spatio-temporal segmentation algorithm. The algorithm incorporates luminance and motion information simultaneously, and uses morphological tools such as morphological filtersand watershed algorithm. The procedure toward complete segmentation consists of three steps:joint marker extraction, boundary decision, and motion-based region fusion. First, the joint marker extraction identifies the presence of homogeneours regions in both motion and luminance, where a simple joint marker extraction technique is proposed. Second, the spatio-temporal boundaries are decided by the watershed algorithm. For this purposek, a new joint similarity measure is proposed. Finally, an elimination ofredundant regions is done using motion-based region function. By incorporating spatial and temporal information simultaneously, we can obtain visually meaningful segmentation results. Simulation results demonstratesthe efficiency of the proposed method.

  • PDF

A Variable Window Method for Three-Dimensional Structure Reconstruction in Stereo Vision (삼차원 구조 복원을 위한 스테레오 비전의 가변윈도우법)

  • 김경범
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.20 no.7
    • /
    • pp.138-146
    • /
    • 2003
  • A critical issue in area-based stereo matching lies in selecting a fixed rectangular window size. Previous stereo methods doesn't deal effectively with occluding boundary due to inevitable window-based problems, and so give inaccurate and noisy matching results in areas with steep disparity variations. In this paper, a variable window approach is presented to estimate accurate, detailed and smooth disparities for three-dimensional structure reconstruction. It makes the smoothing of depth discontinuity reduced by evaluating corresponding correlation values and intensity gradient-based similarity in the three-dimensional disparity space. In addition, it investigates maximum connected match candidate points and then devise the novel arbitrarily shaped variable window representative of a same disparity to treat with disparity variations of various structure shapes. We demonstrate the performance of the proposed variable window method with synthetic images, and show how our results improve on those of closely related techniques for accuracy, robustness, matching density and computing speed.

Effect of variable viscosity on combined forced and free convection boundary-layer flow over a horizontal plate with blowing or suction

  • Mahmoud, Mostafa A.A.
    • Journal of the Korean Society for Industrial and Applied Mathematics
    • /
    • v.11 no.1
    • /
    • pp.57-70
    • /
    • 2007
  • The effects of variable viscosity, blowing or suction on mixed convection flow of a viscous incompressible fluid past a semi-infinite horizontal flat plate aligned parallel to a uniform free stream in the presence of the wall temperature distribution inversely proportional to the square root of the distance from the leading edge have been investigated. The equations governing the flow are transformed into a system of coupled non-linear ordinary differential equations by using similarity variables. The similarity equations have been solved numerically. The effect of the viscosity temperature parameter, the buoyancy parameter and the blowing or suction parameter on the velocity and temperature profiles as well as on the skin-friction coefficient and the Nusselt number are discussed.

  • PDF

The Effect of Heat Conduction resistance on Laminar Film Condensation along a Horizontal Plate (수평평판의 막응축에서 전도 열저항의 영향)

  • Lee, Euk-Soo
    • Proceedings of the Korean Society of Marine Engineers Conference
    • /
    • 2005.06a
    • /
    • pp.183-188
    • /
    • 2005
  • The effect of heat conduction resistance on laminar film condensation of the pure saturated vapor in forced flow over a flat plate has been investigated as boundary layer solutions. A efficient numerical methods for water are proposed for its solution. The momentum and energy balance equations are reduced to a nonlinear system of ordinary differential equations with four parameters: the Prandtl number, Pr, Modified Jacob number, $Ja^{\ast}/Pr$, defined by an overall temperature difference, a property ratio $\sqrt{P_l{\mu}_l/P_v{\mu}_v}$ and the conjugate parameter ${\zeta}$. The similarity and simplified solutions obtained reveal the effects of the conjugate parameter.

  • PDF

Analysis of the Flow of a Circular Nozzle using a slant Hot-Wire (단일 경사열선을 이용한 원형노즐의 유동해석)

  • Chung, Wui-Jun;Oh, Sang-Han
    • The KSFM Journal of Fluid Machinery
    • /
    • v.12 no.2
    • /
    • pp.17-23
    • /
    • 2009
  • The program using $C/C^{++}$ which could calculate 3-D velocities from data of the flowfield obtained by a slant hot-wire has been developed. The characteristic of the exit flowfield of a circular nozzle with a curved surface was investigated. From the result, the inward-flow was verified at adjacent layers near the boundary of the exit flowfield of a circular nozzle in Id and outward-flow was sensed gradually from down-flow of Id. Similarity of the nondimensional velocity profile properlly could be obtained except near Id and the virtual origin reasonably could be obtained.

An Analytic Analysis for a Two-Dimensional Floating and Fluid-Filled Membrane Structure (부유식 유체저장용 2차원 막구조물의 이론적 해석)

  • Choi, Yoon-Rak
    • Journal of Ocean Engineering and Technology
    • /
    • v.23 no.4
    • /
    • pp.32-37
    • /
    • 2009
  • An analytic similarity shape solution was studied for a two-dimensional floating and fluid-filled membrane structure. The static shape of a membrane structure can be expressed as a set of nonlinear ordinary differential equations. The integration of curvature leads to an analytic solution for the shape, which contains unknown boundary values. Matching the upper and lower shapes at the free surface incorporated with their buoyancy allowed the unknowns to be determined. Some characteristic values of similarity shapes were evaluated and shapes are illustrated for various density ratios and volume efficiency ratios.

A Study on Efficient FPS Game Operation Using Attention NPC Extraction (관심 NPC 추출을 이용한 효율적인 FPS 게임 운영에 관한 연구)

  • Park, Changmin
    • Journal of Korea Society of Digital Industry and Information Management
    • /
    • v.13 no.2
    • /
    • pp.63-69
    • /
    • 2017
  • The extraction of attention NPC in a FPS game has emerged as a very significant issue. We propose an efficient FPS game operation method, using the attention NPC extraction with a simple arithmetic. First, we define the NPC, using the color histogram interaction and texture similarity in the block to determine the attention NPC. Next, we use the histogram of movement distribution and frequency of movement of the NPC. Becasue, except for the block boundary according to the texture and to extract only the boundaries of the object block. The edge strength is defined to have high values at the NPC object boundaries, while it is designed to have relatively low values at the NPC texture boundaries or in interior of a region. The region merging method also adopts the color histogram intersection technique in order to use color distribution in each region. Through the experiment, we confirmed that NPC has played a crucial role in the FPS game and as a result it draws more speed and strategic actions in the game.

Character Recognition using Regional Structure

  • Yoo, Suk Won
    • International Journal of Advanced Culture Technology
    • /
    • v.7 no.1
    • /
    • pp.64-69
    • /
    • 2019
  • With the advent of the fourth industry, the need for office automation with automatic character recognition capabilities is increasing day by day. Therefore, in this paper, we study a character recognition algorithm that effectively recognizes a new experimental data character by using learning data characters. The proposed algorithm computes the degree of similarity that the structural regions of learning data characters match the corresponding regions of the experimental data character. It has been confirmed that satisfactory results can be obtained by selecting the learning data character with the highest degree of similarity in the matching process as the final recognition result for a given experimental data character.