• Title/Summary/Keyword: Geometric similarity

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Analysis of Pedestrian Flow Characteristics in Subway Station (지하역사 기본 모델에 대한 여객 유동 특성 해석)

  • Nam Seong-Won
    • Journal of the Korean Society for Railway
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    • v.9 no.3 s.34
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    • pp.271-276
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    • 2006
  • Insight into behaviour of pedestrians as welt as tools to assess passenger flow condition is important in such instances as planning and geometric design of railway station under regular and safety-critical circumstances. Algorithm for passenger flow analysis based on DEM (Discrete Element Method) is newly developed. There are lots of similarity between particle-laden two phase flow and passenger flow. The velocity component of 1st phase corresponds to the unit vector of calculation cell, each particle to passenger, volume fraction to population density and the particle velocity to the walking velocity, etc. And, the walking velocity of passenger is also represented by the function of population density. Key algorithms are developed to determine the position of passenger, population density and numbering to each passenger. To verify the effectiveness of new algorithm, passenger flow analysis for the basic models of railway station is conducted.

A Gaze Tracking based on the Head Pose in Computer Monitor (얼굴 방향에 기반을 둔 컴퓨터 화면 응시점 추적)

  • 오승환;이희영
    • Proceedings of the IEEK Conference
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    • 2002.06c
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    • pp.227-230
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    • 2002
  • In this paper we concentrate on overall direction of the gaze based on a head pose for human computer interaction. To decide a gaze direction of user in a image, it is important to pick up facial feature exactly. For this, we binarize the input image and search two eyes and the mouth through the similarity of each block ( aspect ratio, size, and average gray value ) and geometric information of face at the binarized image. We create a imaginary plane on the line made by features of the real face and the pin hole of the camera to decide the head orientation. We call it the virtual facial plane. The position of a virtual facial plane is estimated through projected facial feature on the image plane. We find a gaze direction using the surface normal vector of the virtual facial plane. This study using popular PC camera will contribute practical usage of gaze tracking technology.

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A Robust Multi-part Tracking of Humans in the Video Sequence (비디오 영상내의 사람 추적을 위한 강인한 멀티-파트 추적 방법)

  • 김태현;김진율
    • Proceedings of the IEEK Conference
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    • 2003.07e
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    • pp.2088-2091
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    • 2003
  • We presents a new algorithm for tracking person in video sequence that integrates the meanshift iteration procedure into the particle filtering. Utilizing the nice property of convergence to the modes in the meanshift iteration we show that only a few sample points are sufficient, while in general the particle filtering requires a large number of sample points. Multi-parts of a person is tracked independently of each other based on the color Then, the similarity against the reference model color and the geometric constraints between multi-parts are reflected as the sample weights. Also presented is the computer simulation results, which show successful tracking even for complex background clutter.

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GENERALIZED EULER PROCESS FOR SYSTEMS OF NONLINEAR DIFFERENTIAL EQUATIONS

  • Yu, Dong-Won
    • Journal of applied mathematics & informatics
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    • v.7 no.3
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    • pp.941-958
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    • 2000
  • Euler method is generalized to solve the system of nonlinear differential equations. The generalization is carried out by taking a special constant matrix S so that exp(tS) can be exactly computed. Such a matrix S is extracted from the Jacobian matrix of the given problem. Stability of the generalized Euler process is discussed. It is shown that the generalized Euler process is comparable to the fourth order Runge-Kutta method. We also exemplify that the important qualitative and geometric features of the underlying dynamical system can be recovered by the generalized Euler process.

A Study on the Configuration Modeling and Aerodynamic Analysis of Small Airplanes for Flight Training (교육용 소형 항공기의 형상 모델링과 공력 분석에 관한 연구)

  • Cho, Hwankee
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.28 no.1
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    • pp.59-65
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    • 2020
  • This paper presents comparative results of configuration modeling and aerodynamic analysis to single-engine airplanes such as C-172, SR-20, and DA40NG. The software OpenVSP was used as an airplane configuration modeling tool. OpenVSP can provide the fastest method to get three-dimensional aircraft configuration from given basic data and drawings of aircraft. Parametric design input in OpenVSP, from given aircraft geometric parameters, was applied to small airplanes mentioned. New aircraft models in this study were reversely designed to coincide with the publicly obtained dimensions of the original aircraft. The basic aerodynamic analysis of newly designed modeling aircraft was performed by the vortex lattice method. Results are shown that the similarity of aerodynamic data obtained except for the lack of DA40NG. In conclusion, the modeling process applied to this work is valuable to obtain conceptual design insight in the reverse design from the small airplanes currently in use for flight training.

Creating Architectural Scenes from Photographs Using Model-based Stereo arid Image Subregioning

  • Aphiboon, Jitti;Papasratorn, Borworn
    • Proceedings of the IEEK Conference
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    • 2002.07c
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    • pp.1666-1669
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    • 2002
  • In the process of creating architectural scenes from photographs using Model-based Stereo 〔1〕, the geometric model is used as prior information to solve correspondence problems and recover the depth or disparity of real scenes. This paper presents an Image Subregioning algorithm that divides left and right images into several rectangular sub-images. The division is done according to the estimated depth of real scenes using a Heuristic Approach. The depth difference between the reality and the model can be partitioned into each depth level. This reduces disparity search range in the Similarity Function. For architectural scenes with complex depth, experiments using the above approach show that accurate disparity maps and better results when rendering scenes can be achieved by the proposed algorithm.

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Numerical Analysis on Passenger Flow for the Model of Railway Station (철도 역사 모델에 대한 여객 유동 해석)

  • Kwon, Hyeok-Bin;Cha, Chang-Hwan;Nam, Seong-Won
    • Proceedings of the KSR Conference
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    • 2006.11b
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    • pp.387-391
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    • 2006
  • Insight into behaviour of pedestrians as well as tools to assess passenger flow conditions are important in for instance planning and geometric design of railway station under regular and safety-critical circumstances. Algorithm for passenger flow analysis based on DEM(Discrete Element Method) is newly developed. There are lots of similarity between particle-laden two phase flow and passenger flow. The velocity component of 1st phase corresponds to the unit vector of calculation cell, each particle to passenger, volume fraction to population density and the particle velocity to the walking velocity, etc. And, the walking velocity of passenger is also represented by the function of population density. Key algorithms are developed to determine the position of passenger, population density and numbering to each passenger. To verify the effectiveness of new algorithm, passenger flow analysis for the basic models of railway station is conducted.

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Performance Characteristic of Regenerative Pumps (재생펌프의 성능 특성에 관한 실험적 연구)

  • Lim, Hyung-Soo;Kang, Shin-Hyoung
    • 유체기계공업학회:학술대회논문집
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    • 2003.12a
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    • pp.361-366
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    • 2003
  • For regenerative pump performance test we made 5 times enlarged and 3 different kinds blade types impeller with similarity. Due to geometrical characteristic of regenerative pump, there are two kinds of groups which effect on performance of it. One is geometric shape of impeller blade and the other is clearance and inlet/outlet head loss. To study performance of regenerative pump with impeller shape changes, we tested it with reducing clearance. And we reconcile performance data in the case of zero clearance and zero inlet/outlet head loss. Finally we could verify the influence of each group.

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The Design Principles and Expressive Characteristics Based on Fractal Concepts - Focused on Painting and Space Design - (프랙탈 개념에 기초한 조형원리와 표현특성 - 회화와 공간조형을 중심으로 -)

  • 김주미
    • Korean Institute of Interior Design Journal
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    • no.37
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    • pp.12-20
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    • 2003
  • The purpose of this study is to propose a new design principles and to analyze the pattern of art and architecture applying fractal concepts. As this study is based on fractal geometry as a natural science, 1 intented to explain the concepts and provide some methods of generating fractal properties. Two major aspects are discussed. Frist, fractals are geometric shapes that are self-similar, in other words, they iterate a basic shape at ever increasing a decreasing dimensions. Self-similarity, irregularity, and scaling are fundamental characteristics of fractal geometry. Second, the fractal concepts of art and design can be analyzed and used as a critical tool. In both criticism and design, fractals provides a tool In fine, fractal geometry can be provided endless possibilities for artists and designers intended in expressing the more complex underlying rhythms and organic patterns of nature.

Research on the Application of Fractal Geometry in Digital Arts

  • Xinyi Shan;Jeanhun Chung
    • International Journal of Internet, Broadcasting and Communication
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    • v.15 no.2
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    • pp.175-180
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    • 2023
  • Fractal geometry, a relatively new branch of mathematics, was first introduced by Benoit Mandelbrot in 1975. Since then, its applications have expanded into various fields of natural science. In fact, it has been recognized as one of the three significant scientific discoveries of the mid-20th century, along with the Dissipative System and Chaos Theory. With the help of fractal geometry, designers can create intricate and expressive artistic patterns, using the concept of self-similarity found in nature. The impact of fractal geometry on the digital art world is significant and its exploration could lead to new avenues for creativity and expression. This paper aims to explore and analyze the development and applications of fractal geometry in digital art design. It also aims to showcase the benefits of applying fractal geometry in art creation and paves the way for future research on sacred geometry.