• 제목/요약/키워드: Distance Function

검색결과 2,113건 처리시간 0.027초

거리 보상 기능이 내장된 가시광 통신 회로 설계와 구현 (Design and Implementation of Visible Light Communication Circuit with a Built-in Distance Compensation Function)

  • 박정욱;이용업
    • 한국통신학회논문지
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    • 제40권4호
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    • pp.740-749
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    • 2015
  • 종래의 LED(Light Emitting Diode) 조명을 사용한 가시광 통신에서 송수신기 회로 사이의 통신 거리가 증가함에 따라 가시광 채널의 페이딩과 채널의 경로손실 특성으로 인해 가시광 수신 회로의 포토다이오드에서 수신된 신호는 불규칙한 크기이며 감쇠된 특성을 가진다. 이런 문제점을 극복하기 위해, 이 논문에서는 가시광 통신의 통신거리 확장을 위해 반드시 필요한 거리 보상 회로가 내장된 비교기 문턱 전압 기반의 가시광 통신 회로를 제안하여 설계하고 가시광 시스템 시스템을 구현한다. 또한, 구현된 문턱값 기반 가시광 통신 시스템을 통신 거리와 통신 시스템 속도에 따라 종래 가시광 통신 시스템과 비교하여 제안된 방식시스템의 성능을 분석한다.

장애물이 있는 경우 단일설비의 최적위치의 결정에 관한 연구 (A Study on Decision of Optimal Point of Single Facility Location when the Application Region is Divided into Two)

  • 강성수
    • 산업경영시스템학회지
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    • 제5권7호
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    • pp.9-15
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    • 1982
  • The rectilinear-distance location problem combines the property of being a very appropriate distance measure for a large number of location problems and the property of being very simple to treat analytically. An obvious question to be asked at the optimal point which is obtained by the rectilinear distance method is, "what if the point is not available as a location site\ulcorner." The point may, for example, be inaccessible or may coincide with the location of another structure, a river, or a municipal park. In this case, one approach that may be employed is to construct contour lines (also called iso-cost or level curves) of the cost function. Contour lines provide considerable insight into the shape of the surface of the total cost function as well as a useful means of evaluating alternative locations for the new facility. But, when there is an obstacle which divides the application area into two. The optimal location(which is acquired by the rectilinear distance method) is not coincide with the minimal cost point and the contour line is occasionally of no use, this paper shows the method of finding a way to decide an optimal point of single facility location in this case.this case.

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Passive Ranging Based on Planar Homography in a Monocular Vision System

  • Wu, Xin-mei;Guan, Fang-li;Xu, Ai-jun
    • Journal of Information Processing Systems
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    • 제16권1호
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    • pp.155-170
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    • 2020
  • Passive ranging is a critical part of machine vision measurement. Most of passive ranging methods based on machine vision use binocular technology which need strict hardware conditions and lack of universality. To measure the distance of an object placed on horizontal plane, we present a passive ranging method based on monocular vision system by smartphone. Experimental results show that given the same abscissas, the ordinatesis of the image points linearly related to their actual imaging angles. According to this principle, we first establish a depth extraction model by assuming a linear function and substituting the actual imaging angles and ordinates of the special conjugate points into the linear function. The vertical distance of the target object to the optical axis is then calculated according to imaging principle of camera, and the passive ranging can be derived by depth and vertical distance to the optical axis of target object. Experimental results show that ranging by this method has a higher accuracy compare with others based on binocular vision system. The mean relative error of the depth measurement is 0.937% when the distance is within 3 m. When it is 3-10 m, the mean relative error is 1.71%. Compared with other methods based on monocular vision system, the method does not need to calibrate before ranging and avoids the error caused by data fitting.

공간구문론에의 거리가중개념 적용에 관한 심층 연구 (An In-depth Study on Applying Metric Weighting to Space Syntax)

  • 김민석;박근송
    • 대한건축학회논문집:계획계
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    • 제34권12호
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    • pp.49-54
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    • 2018
  • Applying metric(distance) factor as weighting to spatial syntax is known to not contribute to the explanatory power for the human movement behavior as compared to the geometric(angle) factor according to the negative results of several related studies. However, Kim & Piao (2017) assumed that there is not a problem of the metric factor itself but a problem of the way of applying the metric factor as weighting, and presented a new possibility of the metric factor as weighting by proposing and verifying the methods of applying the metric weighting, which are different from the existing ones. The purpose of this study is to propose advanced methods of applying the metric weighting to space syntax, and to verify whether they contribute to the improvement of explanatory power of space syntax analysis. In this paper, we propose functions for combined depth of distance-step that combine the distance-weighted depth function with the step depth function and apply them to axial segment analysis to check the improvement of explanatory power of them.

회전하는 원통과 병진운동하는 평판사이의 윤활유동해석 (Analysis for Lubrication between a Rotating Cylinder and a Translating Plate)

  • 정호열;정재택
    • Tribology and Lubricants
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    • 제18권6호
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    • pp.411-417
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    • 2002
  • Two dimensional slow viscous flow between a rotating cylinder and a translating plate is investigated using Stokes' approximation. An exact formal expression of the stream function is obtained by using the bipolar cylinder coordinates and Fourier series expansion. From the stream function obtained, the streamline patterns are shown and the pressure distribution in the flow field is determined. By integrating the stress distributions on the cylinder, the farce and the moment exerted on the cylinder are calculated. The flow rate through the gap between the cylinder and the plate is also determined as a function of the distance between the cylinder and the plate. Special attention is directed to the case of very small distance between the cylinder and the plate concerned with the lubrication theory and the minimum pressure is calculated to explain a possible cavitation.

확률론적 이론에 기초한 동적 통행시간 모형 정립 (Development of Probability Theory based Dynamic Travel Time Models)

  • 양철수
    • 대한교통학회지
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    • 제29권3호
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    • pp.83-91
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    • 2011
  • 이 논문은 확률론적인 방법을 이용하여 동적 통행시간(dynamic travel time) 모형을 도출한다. 동적 통행시간 모형은 차량의 통행시간은 도로 공간상에서의 교통흐름 분포에 따라, 또는 통행구간 출발점에서 시간에 대한 교통흐름의 분포에 따라 결정된다고 가정하여 얻어진다. 이 모형들에서 교통흐름의 분포가 차량의 통행시간에 미치는 정도를 나타내는 확률밀도함수(probability density function)는 여러 가지 형태의 도입될 수 있으나 지수분포를 따른다고 가정한다.

대수기하부호와 Hermitian 함수체의 부분체 (Algebraic Geometric Codes and Subfields of Hermitian Function Field)

  • 양경철
    • 한국통신학회논문지
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    • 제19권3호
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    • pp.418-424
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    • 1994
  • GF(q2) 위의 Hermitian 함수체와 마찬가지로, q+1을 나누는 정수 s에 대해 y + y=x 로 정의되는 부분체들도 Hasse-Weil 한계식에 의해 허용되는 최대수의 1차 점들을 가지므로 최상이 된다. 본 논문에 서는 Hermitian 함수체의 이러한 부분체들로부터 생성되는 기하 Goppa 부호(혹은 대수기하부호)룰 연구한다. n을 부호장, m을 이들 부호의 차원과 최소거리를 결정하는 패러미터라 할때, n보다 작은 임의의 m에 대해 차원과 최소거리가 명확하면서도 완전하게 주어진다.

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가상 거리 함수를 이용한 이동 로봇의 지역 장애물 회피 방법 (Local Obstacle Avoidance Method of Mobile Robot Using Virtual Distance Function)

  • 임춘환;김성철;편석범
    • 전자공학회논문지T
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    • 제35T권3호
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    • pp.67-75
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    • 1998
  • 이 논문은 이동 장애물 회피를 위한 새로운 로봇 동작 계획을 제안한다. 이동 장애물의 운동성을 고려하여, 로봇과 장애물 사이의 관계를 위해 가상거리 함수를 정의한다. 각각의 샘플링 시간에, 장애물의 움직임을 고려한 인공 전위계를 구성하기 위해 가상거리 함수를 이용한다. 로봇은 인공 전위 함수에 의해 유도된 인력과 척력 벡터에 따라 이동한다. 제안된 알고리즘은 실시간으로 이동 장애물을 회피할 수 있었다. 시뮬레이션 결과를 통해 제안된 알고리즘의 효율성을 입증한다.

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설비간(設備間) 거리유지(距離維持) 기능(機能)을 고려(考慮)한 다기준(多基準) 설비배치(設備配置) 모델 (A Multiple-criteria Facility Layout Model Considering the Function for Maintaining the Distance between Facilities)

  • 최창호;이상용
    • 품질경영학회지
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    • 제21권1호
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    • pp.190-198
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    • 1993
  • A multiple criteria model for the facility layout problem considers both of the quantitative, the cost of the work flow, and qualitative, the closeness rating score, aspect. Rosenblatt, Fortenberry & Cox and Urban have developed multiple criteria models that consider both of the quantitative and qualitative aspect. Fortenberry & Cox's multiplicity model penalizes facilities with undesirable closeness rating and high work flows more than those undesirable closeness rating and low work flow between them to contribute to the objective function regardless of the closeness rating between these facilities. In this paper, it is intended to develops a improved multiple-criteria facility layout model considering the function for maintaning the distance between facilities.

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A Mixed Co-clustering Algorithm Based on Information Bottleneck

  • Liu, Yongli;Duan, Tianyi;Wan, Xing;Chao, Hao
    • Journal of Information Processing Systems
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    • 제13권6호
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    • pp.1467-1486
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    • 2017
  • Fuzzy co-clustering is sensitive to noise data. To overcome this noise sensitivity defect, possibilistic clustering relaxes the constraints in FCM-type fuzzy (co-)clustering. In this paper, we introduce a new possibilistic fuzzy co-clustering algorithm based on information bottleneck (ibPFCC). This algorithm combines fuzzy co-clustering and possibilistic clustering, and formulates an objective function which includes a distance function that employs information bottleneck theory to measure the distance between feature data point and feature cluster centroid. Many experiments were conducted on three datasets and one artificial dataset. Experimental results show that ibPFCC is better than such prominent fuzzy (co-)clustering algorithms as FCM, FCCM, RFCC and FCCI, in terms of accuracy and robustness.