• Title/Summary/Keyword: Obstacle analysis

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A Study of Analysis for Obstacle Reasons of Open School Management - Based on Elementary School in Chungbuk province - (열린 학교 운영의 저해 요인 분석에 관한 연구 - 충청북도내 초등학교를 중심으로 -)

  • Chong, Kwan-Young;Choi, Hyo-Seung
    • Journal of the Korean Institute of Educational Facilities
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    • v.4 no.4
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    • pp.17-28
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    • 1997
  • The purpose of this study is to search for the effective way of development in managing Open Education Schools by analyzing obstacle reasons for school management of elementary school teachers on the basis of classroom site. This study researched 240 teachers and head teachers in three cities and counties of Chungbuk province through questionnaires which enquire obstacle reasons for Open Education. This research regarded 9 items including curriculum management and teaching method as main factors for consisting of Open Education School. And this analyzed the reactions from the percentages of interviewees. As a result of this analysis. obstacle reasons are as follows. 1. priority for academic background and the lack of school facilities and materials. 2. deficiency of teachers' belief in Open Education and unskilled practice. 3. closed situation in decision making and communication. 4. unreasonable management of finance and school facilities.

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Numerical Analysis on Recirculation Generated by Obstacles around a Cooling Tower (냉각탑 주위의 장애물에 의한 재순환 현상에 관한 수치해석)

  • Lee Jung-Hee;Choi Young-Ki
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.18 no.7
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    • pp.578-586
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    • 2006
  • The present study has been conducted to examine the effect of obstacles around a cooling tower and an air-guide to prevent recirculation. In order to analyze the interaction between external flow and cooling tower exit flow, the external region as well as the cooling, tower are included in computational domain. Two dimensional analysis is performed using the finite volume method with non-orthogonal and unstructured grid system. The standard ${\kappa}-{\varepsilon}$ turbulence model is used. To investigate the recirculation phenomena, flow and temperature fields are calculated with three approaches such as, the distance between cooling tower and obstacle, the allocated geometrical type, and the effect of height of obstacle. In addition, the air-guide is considered in the current computation. The mean recirculation rate increases with the height of obstacle. The effect of air-guide to reduce the mean recirculation rate is obviously observed.

chaotic behavior analysis in the mobile robot : the case of Arnold equation

  • Kim, Youngchul;Kim, Juwan;Kim, Yigon
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2003.09b
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    • pp.110-113
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    • 2003
  • In this paper, we propose that the chaotic behavior analysis in the mobile robot of embedding Arnold equation with obstacle. In order to analysis of chaotic behavior in the mobile robot, we apply not only qualitative analysis such as time-series, embedding phase plane, but also quantitative analysis such as Lyapunov exponent in the mobile robot with obstacle. In the obstacle, we only assume that all obstacles in the chaos trajectory surface in which robot workspace has an unstable limit cycle with Van der Pol equation.

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Chaotic behavior analysis in the mobile robot : the case of Chuas equation

  • Youngchul Bae;Kim, Juwan;Kim, Yigon
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2003.09b
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    • pp.5-8
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    • 2003
  • In this paper, we propose that the chaotic behavior analysis in the mobile robot of embedding Chua's equation with obstacle. In order to analysis of chaotic behavior in the mobile robot, we apply not only qualitative analysis such as time-series, embedding phase plane, but also quantitative analysis such as Lyapunov exponent in the mobile robot with obstacle. In the obstacle, we only assume that all obstacles in the chaos trajectory surface in which robot workspace has an unstable limit cycle with Van der Pol equation

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A Test of the Aviation Obstacle Light and Structural Improvement (태양전지식 항공장애등 성능특성시험 및 구조개선)

  • Byun, Gang;Min, Byeong-Wook;Kim, Sae-Hyun;Lee, Dong-Il;Shin, Gu-Yong;Lee, Sung-Doo
    • Proceedings of the KIEE Conference
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    • 2003.07a
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    • pp.442-444
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    • 2003
  • For the safety of aircraft, aviation obstacle lights must be attached to the transmission towers in accordance with the governing law. Aviation obstacle lights which consist of solar cells, batteries. xenon lamps and a regulator substituted for aviation obstacle lights using AC power. A xenon lamp has advantage such as high brightness but also has disadvantage like large power consumption which cause lighting system to have many solar cells and batteries. This paper introduces an application of a aviation obstacle light using LED lamp through the economic analysis between LED lamp and xenon lamp.

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Comparison of Spatio-temporal Gait Parameters between Paretic and Non-paretic Limb while Stepping over the Different Obstacle's Heights in Subjects with Stroke (편마비 환자의 장애물 높이에 따른 마비측과 비마비측 하지의 시공간적 보행변수 비교)

  • Han, Jin-Tae
    • Journal of the Korean Society of Physical Medicine
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    • v.9 no.1
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    • pp.69-74
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    • 2014
  • PURPOSE: The aim of this study is to compare the spatio-temporal gait parameters between paretic and non-paretic limb while stepping over the different obstacle's heights in subjects with stroke. METHODS: Nine subjects with stroke were participated in this study. Subjects were asked to step over obstacles with a different height. 8 camera motion analysis system(Motion Analysis Corporation, Santa Rosa, USA) was used to measure spatio-temporal parameters. The two way repeated measurement ANOVA was used to compare spati-temporal gait parameters between paretic and non-paretic limbs while stepping over a different obstacle's height(0cm, 10cm, 20cm). RESULTS: Step width, velocity, single supoort time, and double support time were not different among obstacle's height(p>0.05) but stride length, step length, and cadence were significantly different(p>0.05). In stride length, cadence, and double support time, the interactions between obstacle's heights and limbs were not different(p>0.05) but it was significantly different in velocity, step length, and single support time(p<0.05). Velocity, stride length, cadence, and double support times were not different between paretic limb and non-paretic limb(p>0.05) but step length and single support times were significantly different between paretic limb and non-paretic limb(p<0.05). CONCLUSION: These results show that there are differences with spatio-temporal gait parameters among obstacle's heights and between paretic and non-paretic limb during obstacle crossing in subjects with stroke.

Characteristics of Spatio-Temporal Parameters in Parkinson's Disese During Walking (보행 시 파킨슨병 환자의 시·공간적 지표의 특성)

  • Lee, Sung-Yong;Woo, Young-Keun;Shin, Seung-Sub;Jung, Seok
    • Physical Therapy Korea
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    • v.15 no.3
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    • pp.35-43
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    • 2008
  • The purpose of this study was to compare spatio-temporal parameters during walking between patients with idiopathic Parkinson's disease and a control group matched for age, height, and weight. Thirty-three subjects were included in this study. Fifteen normal subjects (age, $63.3{\pm}5.8$ yrs; height, $164.1{\pm}8.7$ cm; weight, $60.7{\pm}17.5$ kg) and eighteen patients (age, $64.0{\pm}7.7$ yrs; height, $164.7{\pm}7.3$ cm; weight, $63.6{\pm}7.7$ kg) participated in the study. The Vicon 512 Motion analysis system was used for gait analysis in each group during walking, with and without an obstacle. The measured spatio-temporal parameters were cadence, walking speed, stride time, step time, single limb support time, double limb support time, stride length, and step length. Results in stride length and step length, when walking without an obstacle, showed a significantly greater decrease in the patient group compared to the control group. During walking with an obstacle, the patient group showed a significantly greater decrease in the step length as compared to the control group. For the control group, there were significant decreases in parameters of cadence and walking speed and increases in parameters of stride time, step time, and single limb support time when walking with an obstacle. The patient group had lower cadence and walking speed and higher stride time, step time, and single limb support time during walking with an obstacle than in walking without an obstacle. These results suggest that patients with Parkinson's disease who walk over an obstacle can decrease cadence, stride length, and step length. Further study is needed, performed with more obstacles and combined with other external cues, such as visual or acoustic guides.

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A Study on Obstacle Factors at the Mutual Access of Towed Trailer of Car-Ferry between Korea and China using Fuzzy-AHP (Fuzzy-AHP를 활용한 한·중 카페리 피견인 트레일러 상호주행 시 장애요인에 관한 연구)

  • Sung, Ki-Deok;Jeon, Jun-Woo;Yeo, Gi-Tae
    • Journal of Navigation and Port Research
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    • v.39 no.6
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    • pp.515-521
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    • 2015
  • The purpose of this study was to analyze the weights of obstacle factors against mutual access of towed trailers of car-ferry between South Korea and China using Fuzzy-AHP. To this end, factors were first selected through literature research and finally selected through in-depth interviews with a group of experts in cargoes who are currently in car-ferry companies. Selected high rank obstacle factors included unstable service provision, limited policy support, and additional costs being incurred and among them, unstable service provision was identified as the most serious obstacle factor through analysis. Eleven measurement variables selected include insufficient supply of container yard, trailer insurance and management issues, insufficient special equipment, insufficient specialized manpower, limited input service courses, insufficient marketing and public relations strategies, and increasing transportation costs and among them, increasing equipment returning costs due to unbalanced cargo gathering were identified as the most serious obstacle factor through analysis followed by limited input service courses, insufficient special equipment, delays in procedures, and occurrence of additional procedures in order of precedence.

Collision Analysis of the Next Generation High-speed EMU Using 3D/1D Hybrid FE Model (3D/1D 하이브리드 유한요소 모델을 이용한 동력 분산형 차세대 고속열차 전체차량의 충돌 해석)

  • Kim, Geo-Young;Koo, Jeong-Seo
    • Transactions of the Korean Society of Automotive Engineers
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    • v.20 no.3
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    • pp.67-76
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    • 2012
  • In this paper, collision analysis of the full rake for the Next Generation High-speed EMU is conducted using a 3D/1D hybrid model, which combines 3-dimensional (3D) front-end structure of finite element model and 1-dimensional (1D) multi-body dynamics model in order to analyze train collision with a standard 3D deformable obstacle. The crush forces, passengers' accelerations and energy absorptions of a full rake train can be easily obtained through a simulation of a 1D dynamics model composed of nonlinear springs, dampers and masses. Also the obtained simulation results are very similar to those of a 3D model if an overriding behavior does not occur during collision. The standard obstacle in TSI regulation has been changed from a rigid body to a deformable body, and therefore 3D collision simulations should be conducted because their simulation results depends on the front-end structure of a train. According to the obstacle collision analysis of this study, the obstacle collides with the driver's upper structure after overriding over the front-end module. The 3D/1D hybrid model is effective to evaluate a main energy-absorbing module that is frequently changed during design process and reduce the need time of the modeling and analysis when compared to a 3D full car body.

Analysis of Distance Error of Stereo Vision System for Obstacle Recognition System of AGV (AGV의 장애물 판별을 위한 스테레오 비젼시스템의 거리오차 해석)

  • 조연상;배효준;원두원;박흥식
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2001.04a
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    • pp.170-173
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    • 2001
  • To apply stereo vision system to obstacle recognition system of AGV, we constructed algorithm of stereo matching and distance measuring with stereo image for positioning of object in area. And using this system, we look into the error between real position and measured position, and studied relationship of compensation.

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