• Title/Summary/Keyword: 4차원

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A Study on the Dimensions of Effectiveness in Korean Public Libraries (우리나라 공공도서관의 효과성 차원에 대한 연구)

  • 홍현진;이용남
    • Journal of the Korean Society for Library and Information Science
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    • v.35 no.1
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    • pp.5-25
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    • 2001
  • The second research of "a study of the evaluation indicators in Korean public libraries" had as its major objective the identification of indicators and broad dimensions of public library effectiveness in Korea. The managers and librarians of the 175 public libraries in the sample were asked to rate the performance of their libraries. Factor analysis was used to derive 11 dimensions of effectiveness. The dimensions fit four different models of organizational effectiveness.ctiveness.

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Passive Localization of Near-Field Sources by Algebraic Path Following (대수적 경로 추종에 의한 근거리 표적의 수동형 위치 추정)

  • 이종환;이균경
    • The Journal of the Acoustical Society of Korea
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    • v.17 no.4
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    • pp.54-59
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    • 1998
  • 이 논문에서는 등간격 선배열 감지기를 사용하여 근거리 표적의 위치 추정을 하는 연산량이 적은 효과적인 대수적 경로 추종 알고리듬을 제안하였다. 원거리 표적의 방위각 추적 알고리듬으로 근거리 표적의 방위각을 추정하면 추정된 방위각은 실제 근거리 표적의 방위각과 거리의 대수적 관계식으로 주어짐을 보였다. 2차원 MUSIC스펙트럼의 극대값을 찾기 위하여 두 개의 결합된 2차원 다항식으로부터 구한 경로를 추종하는 기존의 방식대신 에 이 대수적 관계식을 경로로 사용한다. L개의 감지기에 M개의 표적 신호가 도달하는 경 우, 제안한 알고리듬은 대수적 경로를 따라 M번의 1차원 탐색을 하므로 2차원 다항식으로 부터 경로를 구하여 2L-2번의 1차원 탐색을 하는 기존의 경로 추종 알고리듬보다 연산량을 줄일 수 있다.

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A Two-Phase Algorithm for Polyhedral 3D Object Reconstruction from Two Orthographic Views (이면도로부터 다면체 복원을 위한이단계 알고리즘)

  • O, Beom-Su;Kim, Chang-Heon
    • Journal of KIISE:Computer Systems and Theory
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    • v.26 no.4
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    • pp.513-526
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    • 1999
  • 3 차원 입체 형상을 표현하기 위한 수단으로서 도면을 사용하는 방법이 생산현장에서 많이 활용되고 있다. 그러나 이 방법은 정투영 과정에서 정보 손실이 발생하기 때문에 3차원 후보 요소의 빈번한 조합 탐색 및 복잡한 기하 연산을 필요로 한다. 특히 , 이면도로부터 복원과정은 면도의 생략으로 인하여 수많은 허요소를 생성한다. 본 논문은 효율적인 허요소 축소를 통하여 이면도로부터 다면체를 바르게 복원하는 이단계 알고리즘을 제안한다. 1 단계에서는 이면도와의 정합성에 필수적인 최소한의 3차원 후보요소를 생성한후 , 정투영시 이면도와 일치하는 부분 물체를 복원한다. 2단계에서는 부분 물체에 직교면을 덧붙임으로써 기하학적으로 타당한 완전 물체를 복원한다. 실험결과를 통하여 제안방법이 기존 방법들에 비해 적은 수의 3차원 후보 요소를 생성시키면서 이면도로로부터 3차원 물체를 빠르게 생성하는 것을 보인다.

OBJECT RECOGNITION ALGORITHM (물체 인지 알고리즘)

  • Shon, Howoong;Cho, Hyun C;Kim, Youngkyung
    • Journal of the Korean Geophysical Society
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    • v.7 no.4
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    • pp.247-253
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    • 2004
  • In this paper, 3D recognizing algorithm which is based on the external shape feature is presented. Since many objects have the regular shape, if we posses the database of pattern and we recognize the object using the database of the object's pattern, it is possible to inspect and/or recognize the objects of many fields. This paper handles on the 3D object recognition algorithm using the geometrical pattern matching by 3D database.

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Recognizing the Direction of Action using Generalized 4D Features (일반화된 4차원 특징을 이용한 행동 방향 인식)

  • Kim, Sun-Jung;Kim, Soo-Wan;Choi, Jin-Young
    • Journal of the Korean Institute of Intelligent Systems
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    • v.24 no.5
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    • pp.518-528
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    • 2014
  • In this paper, we propose a method to recognize the action direction of human by developing 4D space-time (4D-ST, [x,y,z,t]) features. For this, we propose 4D space-time interest points (4D-STIPs, [x,y,z,t]) which are extracted using 3D space (3D-S, [x,y,z]) volumes reconstructed from images of a finite number of different views. Since the proposed features are constructed using volumetric information, the features for arbitrary 2D space (2D-S, [x,y]) viewpoint can be generated by projecting the 3D-S volumes and 4D-STIPs on corresponding image planes in training step. We can recognize the directions of actors in the test video since our training sets, which are projections of 3D-S volumes and 4D-STIPs to various image planes, contain the direction information. The process for recognizing action direction is divided into two steps, firstly we recognize the class of actions and then recognize the action direction using direction information. For the action and direction of action recognition, with the projected 3D-S volumes and 4D-STIPs we construct motion history images (MHIs) and non-motion history images (NMHIs) which encode the moving and non-moving parts of an action respectively. For the action recognition, features are trained by support vector data description (SVDD) according to the action class and recognized by support vector domain density description (SVDDD). For the action direction recognition after recognizing actions, each actions are trained using SVDD according to the direction class and then recognized by SVDDD. In experiments, we train the models using 3D-S volumes from INRIA Xmas Motion Acquisition Sequences (IXMAS) dataset and recognize action direction by constructing a new SNU dataset made for evaluating the action direction recognition.

Generation of the Building Layer of Large-scale Digital Map Using Multi-Oblique Images (다방향 경사영상을 이용한 대축척 수치지도 건물레이어 제작)

  • Song, Jai-Youl;Lee, Byoung-Kil
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.29 no.6
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    • pp.621-629
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    • 2011
  • According to the development of technologies for generating the 3D spatial information, the needs for producing and updating the precise 3D objects with LoD 4 level are increased. On the other hand, the needs for real-time updating of 2D digital maps are expanded, based on the execution of various GIS projects. These 2D informations can be extracted from precisely constructed 3D spatial information, to do this the feasibility studies on extraction of the 2D information from the 3D spatial information is needed. In this study, 3D objects are modeled using multi-oblique images, and the objects are stereo-plotted using digital airborne images, as well. Then the two data sets are compared and analyzed. The results show that the accuracy assessments fulfill the 1/1,000 digital map accuracy standard of regulations for photogrametric surveying of National Geographic Information Institute, but the shapes and the areas of building objects are different between two data sets because of the portrayal standards. Consequently, researchers can conclude that it is possible to generate the building layer of large scale topographic map using multi-oblique images, but additional researches is needed to resolve the problems on differences of the portrayal standards.

New 4-Dimensional Constellation-Rotation Modulation Method for DVB-NGH (DVB-NGH를 위한 새로운 4차원 성상 회전 변조기법)

  • Kim, Jun-Ho;Kim, Ho-Jun;Jung, Tae-Jin
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.35 no.11A
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    • pp.1073-1077
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    • 2010
  • This paper proposes a new 4-dimensional(4D) constellation-rotation(CR) method which obtains diversity gain of 4 under Rayleigh fading channels. The proposed scheme uses two consecutive CR operations for the constellation of QAM signals unlike a conventional 2-dimensional(2D) CR method using only one CR operation. The computer simulation results show that the new method outperforms the conventional one even more as both the channel code rate and the erasure ratio increase. In a point of system flexibility, the proposed scheme has a great advantage since the conventional 2D CR scheme can be simply implemented by only changing rotation angle values used in the proposed scheme.

Three-Dimensional Object Recognition System Using Shape from Stereo Algorithm (스테레오 기법을 적용한 3차원 물체인식 시스템)

  • Heo, Yun-Seok;Hong, Bong-Hwa
    • The Journal of Information Technology
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    • v.7 no.4
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    • pp.1-8
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    • 2004
  • The depth information of 3D image lost by projecting 3D-object to 2D-screen for earning image. If depth information is restored and is used to recognize 3D-object, we can make the more effective recognition system. We often use shape from stereo algorithm in order to restore this information. In this paper, we suggest 3-D object recognition system in which the 3-D Hough transform domain is employed to represent the 3-D objects. In this system, we use the moving vector of object to reduce matching time and In second matching step, the unknown input image is compared with the reference images, which is made with octree codes. Octree codes are used in volume-based representation of a three dimensional object. The result of simulation show that the proposed 3-D object recognition system provides satisfactory performance.

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Design and implementation of a three-dimensional broadcasting system based on DTV (디지털 TV기반 3차원 방송 시스템 설계 및 구현)

  • Yun, Kug-Jin;Cho, Suk-Hee;Hur, Nam-Ho;Kim, Jin-Woong;Lee, Soo-In;Ahn, Chi-Eteuk
    • Journal of Broadcast Engineering
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    • v.11 no.4 s.33
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    • pp.483-494
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    • 2006
  • In this paper, we propose a novel program specific information structure(PSI) in MPEG-2 system for a three-dimensional broadcasting system while guaranteeing compatibility with the conventional digital broadcasting system. The proposed PSI structure including a descriptor of contents type, 2D or 3D, provides service providers with a function of combining 2D and 3D contents freely. However the descriptor is ignored in the conventional digital broadcasting set-top box. With the proposed PSI structure, we designed and implemented a three-dimensional broadcasting system. The proposed system has 2D or 3D display mode for providing user's preference in a three-dimensional broadcasting environment.

Generalized Kinematic Analysis for the Motion of 3-D Linkages using Symbolic Equation (기호방정식을 이용한 3차원 연쇄기구 운동해석의 일반화)

  • 김호룡
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.10 no.1
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    • pp.102-109
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    • 1986
  • Based on the Hartenberg-Denavit symbolic equation, which is one of equations for the kinematic analysis of three dimensional (3-D) linkage, a generalized kinematic motion equation is derived utilizing Euler angles and employing the coordinates transformation. The derived equation can feasibly be used for the motion analysis of any type of 3-D linkages as well as 2-D ones. In order to simulate the general motion of 3-D linkgages on digital computer, the generalized equation is programmed through the process of numerical analysis after converting the equation to the type of Newton-Raphson formula and denoting it in matrix form. The feasibility of theoretically derived equation is experimentally proved by comparing the results from the computer with those from experimental setup of three differrent but generally empolyed 3-D linkages.