• Title/Summary/Keyword: Distance measure

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Measuring Connectivity in Heterogenous Landscapes: a Review and Application (이질적 경관에서의 연결성 측정: 리뷰 및 적용)

  • Song, Wonkyong;Kim, Eunyoung;Lee, Dong-Kun
    • Journal of Environmental Impact Assessment
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    • v.21 no.3
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    • pp.391-407
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    • 2012
  • The loss of connectivity and fragmentation of forest landscapes are seriously hindering dispersal of many forest-dwelling species, which may be critical for their viability and conservation by decreasing habitat area and increasing distance among habitats. For understanding their environmental impacts, numerous spatial models exist to measure landscape connectivity. However, general relationships between functional connectivity and landscape structure are lacking, there is a need to develop landscape metrics that more accurately measure landscape connectivity in whole landscape and individual patches. We reviewed functional and structural definition of landscape connectivity, explained their mathematical connotations, and applied representative 13 indices in 3 districts of Seoul having fragmented forest patches with tits, the threshold distance was applied 500m by considering the dispersal of tits. Results of correlation and principal component analysis showed that connectivity indices could be divided by measurement methods whether they contain the area attribute with distance or not. Betweenness centrality(BC), a representative index measuring distance and distribution among patches, appreciated highly stepping stone forest patches, and difference of probability of connectivity(dPC), an index measuring including area information, estimated integrated connectivity of patches. Therefore, for evaluating landscape connectivity, it is need to consider not only general information of a region and species' characteristics but also various measuring methods of landscape connectivity.

Comparison of Distance of Subacromial Space Using Ultrasonographic Measurement on Arm Positions of Shoulder Injured Patients (견부손상환자의 팔의 자세에 따른 초음파 영상을 이용한 견봉하공간 거리의 비교)

  • Jee, Eun-Mi;Kim, Suhn-Yeop;Park, Ji-Whan
    • Journal of the Korean Society of Physical Medicine
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    • v.6 no.4
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    • pp.397-406
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    • 2011
  • Purpose : Recently ultrasound images has been used to measure the subacromial space with a linear measurement of the acromiohumeral distance. The purpose of this study was to comparison of distance of subacromial space using ultrasonographic measurement on arm positions of shoulder injured patients. Methods : The subjects were 30 shoulder injured patients (19 males and 11 females). Ultrasonography was performed to measure subacromial space during each shoulder resting position, $45^{\circ}$ abduction, internal rotation with $45^{\circ}$ abduction and external rotation with $45^{\circ}$ abduction. Results : Subacromial space was a significantly difference between injured arm and normal arm at shoulder resting position. At $45^{\circ}$ abduction, subacromial space was narrowing significantly between injured arm and normal arm. At external rotation with $45^{\circ}$ abduction, subacromial space were wider in normal arm than in injured arm but it was not significantly. Intra-observer reliability for ultrasonography measurement of subacromial distance was excellent (.96~.99). Conclusion : These results identified that positions of injured shoulder was related to subacromion space.

A Multi-Resolution Distance Measure in Two Dimensional Images Using Proposed Grey Block Distance Algorithms (제안된 GBD 알고리즘을 이용한 이차원 영상에서의 다중해상도 거리 측정)

  • Hong, Jun-Sik;Jung, Soon-Won
    • Proceedings of the Korea Contents Association Conference
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    • 2006.05a
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    • pp.392-397
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    • 2006
  • In this paper, we have proposed a revised GBD algorithm to make a relative identification more easily between 2-Dimensional images being compared with the well-known GBD(Grey Block Distance) algorithm. The method proposed here can measure the information about both the whole images and partial image. Also it can improve the performance of the existing GBD algorithm to do not loose the information of the partial image which has been changed rapidly in the 2-D image application. From the results of the experimental simulation we can say that the proposed method can be identified 2-D images more easily than that of the existing GBD algorithm.

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A Study on Scale-Invariant Features Extraction and Distance Measurement for Localization of Mobile Robot (이동로봇의 위치 추정을 위한 스케일 불변 특징점 추출 및 거리 측정에 관한 연구)

  • Jung, Dae-Seop;Jang, Mun-Suk;Ryu, Je-Goon;Lee, Eung-Hyuk;Shim, Jae-Hong
    • Proceedings of the KIEE Conference
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    • 2005.10b
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    • pp.625-627
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    • 2005
  • Existent distance measurement that use camera is method that use both Stereo Camera and Monocular Camera, There is shortcoming that method that use Stereo Camera is sensitive in effect of a lot of expenses and environment variables, and method that use Monocular Camera are big computational complexity and error. In this study, reduce expense and error using Monocular Camera and I suggest algorithm that measure distance, Extract features using scale Invariant features Transform(SIFT) for distance measurement, and this measures distance through features matching and geometrical analysis, Proposed method proves measuring distance with wall by geometrical analysis free wall through feature point abstraction and matching.

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Nerve length measurement method in a radial motor nerve conduction study

  • Kim, Jae-Gyum;Kim, Yoohwan;Seok, Hung Youl;Kim, Byung-Jo
    • Annals of Clinical Neurophysiology
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    • v.19 no.1
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    • pp.28-33
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    • 2017
  • Background: Previous studies of radial nerve conduction study (NCS) did not present how to measure the length of the radial nerve across the elbow, and did not even mention how to manage the spiral course of the nerve. This study aimed to applicate the most reliable method to measure the length of the radial nerve during NCS. Methods: Three points (A, B, and C) were determined along the relatively straight course of the radial nerve. The distance was measured using three different methods: L1) straight distance corresponding to the A-C distance, L2) sum of the distances corresponding to the A-B-C distance, L3) based on the L2, but the elbow is flexed at a $45^{\circ}$ angle. We compared the three methods of distance measurement and the calculated nerve conduction velocities (V1, V2, and V3) in normal healthy subjects. Results: 19 normal participants were enrolled. The mean value for method L1, L2 and L3 were $22.5{\pm}1.8cm$, $24.0{\pm}2.1cm$, and $23.2{\pm}2.1cm$ (p < 0.001). Calculated conduction velocities using those distance measurement methods as follows (p < 0.001): V1 ($60.9{\pm}2.7m/s$), V2 ($64.6{\pm}3.3m/s$), and V3 ($63.4{\pm}3.9m/s$). V2 was significantly greater than V1 and V3 (p < 0.001, p = 0.010, respectively). Conclusions: The distance measurement using a stopover point near the lateral epicondyle between two stimulus points in position of a fully extended elbow with forearm pronation is the most appropriate posture for radial motor NCS.

철도차량의 비상제동거리 해석 시스템

  • 진원혁;이성창;김대은
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1995.10a
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    • pp.747-750
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    • 1995
  • As railway trains run faster high performance braking system are necessary because more energy needs to be dissipated due to increased kinetic energy. In this work a portable computer based prediction system for emergency braking distance has been developed. The algorithm for the system is based on braking theory and empirical results of actual braking test. The computer is connected to the sensors to measure the velocity and the braking pressure in real train. It is expected that this system will be utilized to predict emergency braking distance during actual operation of the train

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Application of slab and plate width measurement using laser distance meter (Laser를 이용한 후물 판재류 및 Slap폭 측정 적용)

  • 최철호
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.1076-1078
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    • 1996
  • According to ascending needs for quality assurance of plate by customer and automated measurement of dimension for slab, in plate mill, project is on preceeding to install measuring system to measure width, length and camber of slab and plate using laser distance meter. In this document, I will describe not technical point of view but idea of design for installation system.

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Object matching algorithms using robust hausdorff distance measure (Robust hausdorff 거리 척도를 이용한 물체 정합 알고리듬)

  • 권오규;심동규;박래홍
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.34S no.11
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    • pp.93-101
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    • 1997
  • A Hausdorff distance (HD) is one of commonly used measures for object matching. It calculates the distance between two point sets of edges in two-dimensional binary images without establishing correspondences. This paper proposes three object matching algorithm using robust HD measures based on M-estimation, least trimmed square (LTS), and .alpha.-trimmed mean methods, which are more efficient than the conventional HD measures. By computer simulation with synthetic and real images, the matching performance of the conventional HD smeasures and proposed' robust ones is compared.

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A Multi-Resolution Distance Measure Using Grey Block Distance Algorithms for Principal Component Analysis (주성분분석에서의 제안된 GBD 알고리즘을 이용한 다중해상도 거리 측정)

  • Hong, Jun-Sik
    • Proceedings of the KIEE Conference
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    • 2002.07d
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    • pp.2671-2673
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    • 2002
  • 본 논문에서는 주성분분석(principal component analysis; 이하 PCA)기법을 이용, 이차원 영상을 분류하여 다중해상도에서 기존의 그레이 블록 거리(grey block distance; GBD, 이하 GBD)알고리즘과 비교하여 이차원 영상간의 상대적 식별을 더 용이하게 하기 위한 새로운 GBD 알고리즘 방법을 제안한다. 이 제시된 방법은 다중해상도에서 기존의 GBD 알고리즘과 비교해서 영상이 급격히 변화하는 부분의 정보를 잃지 않게 개선할 수 있었다. 모의 실험 결과로부터 기존의 GBD 알고리즘에 비하여 상대적 식별이 더 용이함을 확인하였다.

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Remote Control of an unmaned vehicle of shortage of hands using Internet (인터넷을 이용한 지능형 무인 차량의 원격제어)

  • 김승철;김남수;임영도
    • Journal of the Institute of Convergence Signal Processing
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    • v.3 no.4
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    • pp.57-61
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    • 2002
  • We design Collision Avoidance System using model vehicle. The purpose of this system(Collision Avoidance System) is to maintain continuously constant distance between a forward running vehicle and a following automatic guided vehicle(AGV). For this system, we design modeling of vehicle and observe this through simulation. By sing super sonic sensors to measure the distance between vehicles and controller using 80c196kc for changing velocity of motor, we design Collision Avoidance System as maintaining continuously constant distance between vehicles.

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