• 제목/요약/키워드: Path length

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K-Shortest Path 알고리즘에 기초한 새로운 대역폭 보장 라우팅 알고리즘 (New Bandwidth Guaranteed Routing Algorithms based on K-Shortest Path Algorithm)

  • 이준호;이성호
    • 한국통신학회논문지
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    • 제28권11B호
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    • pp.972-984
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    • 2003
  • 본 논문에서는 MPLS 네트워크에서 LSP 설정에 적용될 수 있는 새로운 대역폭 보장 온라인 라우팅 알고리즘들을 제안하고 기존의 알고리즘들과 함께 그 성능을 시뮬레이션을 통해서 평가한다. 제안된 방식은 기존의 WSP나 SWP 알고리즘을 K-shortest loopless path 알고리즘에 기초해서 확장시킨 형태를 가진다. 시뮬레이션을 통해서 accepted bandwidth, accepted request number 그리고 average path length라는 성능을 평가한 결과, 모든 노드들이 LSP 설정의 ingress나 egress 노드가 될 수 있는 상황에서 제안된 방식들이 전반적으로 우수한 성능을 보였는데 네트워크 부하가 큰 경우에는 특히, 최소 홉 경로에 기초한 방식들이 좋은 성능을 보임을 알 수 있다.

등고선가공에서의 기술적 요구사항 들 (Technological Requirements in Z-level Machining)

  • 박상철
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2001년도 춘계학술대회논문집C
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    • pp.128-133
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    • 2001
  • For the Z-level machining, a tool-path linking procedure is presented. The linking problem is approached from the technological requirements, such as considering the machining constraints among the tool-path-elements, minimizing the tool-path length and reflecting the oneway/zigzag linking option. To simplify the linking problem, we develop a data structure, called a TPE-net, providing information on the machining constraints among the tool-path-elements. By making use of the TPE-net, the tool-path linking problem becomes a touring problem so that every node has been traversed.

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경로 교통량 시뮬레이션 기법을 이용한 간선구간 설정 방법론 연구 (A Path-Volume Simulation Method to Select Arterial Section of Road Network)

  • 황준문;조중래;손영태
    • 대한교통학회지
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    • 제19권5호
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    • pp.85-97
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    • 2001
  • 최근 급격히 증가하고 있는 교통수요에 능동적으로 대처해 나가기 위해서는 도시 가로망이 도시교통환경에서 담당하는 교통기능을 체계적으로 분석하여 도로의 기능적 위계를 이루고, 제약된 예산 하에 최대의 효율을 누릴 수 있는 교통관리계획이나 시설계획을 수립해야 할 것이다. 그러나 기능적 위계의 설정 지표 중 중요도가 높은 차량의 운행경로는 조사상 불가능하거나 큰 어려움을 내포하고 있다. 이러한 문제점을 해결하기 위해 본 논문에서는 Simulation기법을 이용하여 차량의 운행경로 및 운행거리를 파악하였다. 이에 본 연구는 특정 경로에 유출입하는 교통량을 알 수 있는 경로OD교통량과 특정 경로내의 특정 노드(i, j)사이에 통과하는 경로교통량이라는 개념을 도입하였다. 이러한 통행량들을 분석하여 도시 가로망의 기능적 분류를 가능케 하는 정량적 지표를 정립하였으며, 더 나아가 효율적 투자계획 및 정책결정권자의 계획방향 판단에 일조할 수 있는 '집중관리구간' 선정영역을 제시하였다.

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발목관절 전략 운동이 80대 노인 여성의 균형능력에 미치는 영향 (The influence of ankle strategy exercise on equilibrium ability in women of octogenarians)

  • 이우형
    • 대한물리치료과학회지
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    • 제17권1_2호
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    • pp.67-76
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    • 2010
  • Background: The purpose of this study was to evaluate the influence of ankle strategy exercise on balance ability in the women of octogenarians. Methods: Ankle strategy exercise group(n=14), leg strengthening exercise group(n=14) were measured an balance ability by Berg Balance Scale(BBS) scores and Balance Performance Monitor(BPM) at pre-intervention and post-intervention in 6weeks. Results: This study were summarized as follows : 1. The BBS scores, sway area, sway path length, sway maximum velocity of ankle strategy exercise group and leg strengthening exercise group were significantly different among the intervention period(p<.05). 2. The improvement of BBS scores, sway area, sway path length, sway maximum velocity were significantly different between ankle strategy exercise group and leg strengthening exercise group at in 6weeks(p<.05). Conclusion: Learned from the ankle strategy exercise could improve BBS scores, sway area, sway path length, sway maximum velocity and a balance for the women of octogenarians. Ankle strategy exercise need to be applied clinically for balance ability of the women of octogenarians.

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트리에서 길이 제한이 있는 가장 무거운 경로를 찾는 알고리즘 (Algorithm for finding a length-constrained heaviest path of a tree)

  • 김성권
    • 정보처리학회논문지A
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    • 제13A권6호
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    • pp.541-544
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    • 2006
  • 에지마다 길이와 무게(둘 다 양수, 음수, 0 가능)가 주어진 트리에서, 길이의 합이 주어진 값 이하이면서 무게의 합이 가장 큰 경로를 찾는 O(nlognloglogn) 시간 알고리즘을 제시한다. 이전의 결과 O($nlog^2n$) 보다 향상된 것이다. 여기서, n은 트리가 가지는 노드의 수이다.

Effect of Kinesiology Taping of the Middle Back on Static Balance in Hemiplegic Stroke Patients: A Pilot Study

  • Kim, Bokyung
    • 국제물리치료학회지
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    • 제12권2호
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    • pp.2354-2358
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    • 2021
  • Background: Stroke is a neurological disorder characterized by an impaired static balance. A change in poor posture after stroke may worsen static balance. The balance control through an upright posture may include kinesiology taping of the middle back. Objectives: To investigated the effect of kinesiology taping of middle back on static balance in patients with stroke. Design: A randomized controlled trial. Methods: A total of 10 patients with stroke were divided into two groups. The experimental and control groups received kinesiology taping and placebo taping of the middle back, respectively. After 24 h, static balance (i.e., sway area and path length) was measured in closed eyes condition. Results: The experimental group (kinesiology taping group) showed a significant decrease in sway area and path length after the intervention. In addition, kinesiology taping group showed a significant decrease in sway area and path length compared to the control group. Conclusion: Kinesiology taping of the middle back can improve static balance in stroke patients.

Measurement of Variation in Water Equivalent Path Length by Respiratory Organ Movement

  • Minohara, Shinichi;Kanai, Tatsuaki;Endo, Masahiro;Kato, Hirotoshi;Miyamoto, Tadaaki;Tsujii, Hirohiko
    • 한국의학물리학회:학술대회논문집
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    • 한국의학물리학회 2002년도 Proceedings
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    • pp.90-93
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    • 2002
  • In particle radiotherapy, a shape of the beam to conform the irradiation field is statically defined by the compensator, collimator and potal devices at the outside of the patient body. However the target such as lung or liver cancer moves along with respiration. This increases the irradiated volume of normal tissue. Prior discussions about organ motions along with respiration have been mainly focused on inferior-superior movement that was usually perpendicular to beam axis. On the other hand, the change of the target depth along the beam axis is very important especially in particle radiotherapy, because the range end of beam (Bragg peak) is so sharp as to be matched to distal edge of the target. In treatment planning, the range of the particle beam inside the body is calculated using a calibration curve relating CT number and water equivalent path length (WEL) to correct the inhomogeneities of tissues. The variation in CT number along the beam path would cause the uncertainties of range calculation at treatment planning for particle radiotherapy. To estimate the uncertainties of the range calculation associated with patient breathing, we proposed the method using sequential CT images with respiration waveform, and analyzed organ motions and WELs at patients that had lung or liver cancer. The variation of the depth along the beam path was presented in WEL rather than geometrical length. In analyzed cases, WELs around the diaphragm were remarkably changed depending on the respiration, and the magnitude of these WEL variations was almost comparable to inferior-superior movement of diaphragm. The variation of WEL around the lung was influenced by heartbeat.

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Post-tuning of Sample Position in Common-path Swept-source Optical Coherence Tomography

  • Park, Jae-Seok;Jeong, Myung-Yung;Kim, Chang-Seok
    • Journal of the Optical Society of Korea
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    • 제15권4호
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    • pp.380-385
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    • 2011
  • Common-path interferometers are widely used for endoscopic optical coherence tomography (OCT) because an arbitrary arm length can be chosen for the endoscopic imaging probe. However, the scheme suffers from the limited range of the sample position distance from the end of the imaging probe because the position between the reference reflector and the sample is limited by the optical path-length difference (OPD) to induce an interference signal. In this study, we developed a novel method for compensating the arbitrary sample position in common-path swept-source OCT by adding an extra Mach-Zehnder interferometer in the post-path of the interfered optical signal. Theoretical analysis and an experimental demonstration of imaging depth tuning for the flexible sample position of an endoscopic OCT image are discussed. After post-tuning of sample position distance, the positioning limitation between the reference reflector and the sample can be solved for various sample positions over a range of 26 mm for the cross-sectional images of a fish eye sample.

Boundary-RRT* Algorithm for Drone Collision Avoidance and Interleaved Path Re-planning

  • Park, Je-Kwan;Chung, Tai-Myoung
    • Journal of Information Processing Systems
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    • 제16권6호
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    • pp.1324-1342
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    • 2020
  • Various modified algorithms of rapidly-exploring random tree (RRT) have been previously proposed. However, compared to the RRT algorithm for collision avoidance with global and static obstacles, it is not easy to find a collision avoidance and local path re-planning algorithm for dynamic obstacles based on the RRT algorithm. In this study, we propose boundary-RRT*, a novel-algorithm that can be applied to aerial vehicles for collision avoidance and path re-planning in a three-dimensional environment. The algorithm not only bounds the configuration space, but it also includes an implicit bias for the bounded configuration space. Therefore, it can create a path with a natural curvature without defining a bias function. Furthermore, the exploring space is reduced to a half-torus by combining it with simple right-of-way rules. When defining the distance as a cost, the proposed algorithm through numerical analysis shows that the standard deviation (σ) approaches 0 as the number of samples per unit time increases and the length of epsilon ε (maximum length of an edge in the tree) decreases. This means that a stable waypoint list can be generated using the proposed algorithm. Therefore, by increasing real-time performance through simple calculation and the boundary of the configuration space, the algorithm proved to be suitable for collision avoidance of aerial vehicles and replanning of local paths.

Multipoint variable generalized displacement methods: Novel nonlinear solution schemes in structural mechanics

  • Maghami, Ali;Shahabian, Farzad;Hosseini, Seyed Mahmoud
    • Structural Engineering and Mechanics
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    • 제83권2호
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    • pp.135-151
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    • 2022
  • The generalized displacement method is a nonlinear solution scheme that follows the equilibrium path of the structure based on the development of the generalized displacement. This method traces the path uniformly with a constant amount of generalized displacement. In this article, we first develop higher-order generalized displacement methods based on multi-point techniques. According to the concept of generalized stiffness, a relation is proposed to adjust the generalized displacement during the path-following. This formulation provides the possibility to change the amount of generalized displacement along the path due to changes in generalized stiffness. We, then, introduce higher-order algorithms of variable generalized displacement method using multi-point methods. Finally, we demonstrate with numerical examples that the presented algorithms, including multi-point generalized displacement methods and multi-point variable generalized displacement methods, are capable of following the equilibrium path. A comparison with the arc length method, generalized displacement method, and multi-point arc-length methods illustrates that the adjustment of generalized displacement significantly reduces the number of steps during the path-following. We also demonstrate that the application of multi-point methods reduces the number of iterations.