• Title/Summary/Keyword: time coordination

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Performance Enhancement Method for Distributed real-time transmission in the wireless LAN (무선랜에서 분산 실시간 전송을 위 한 성능향상 방법)

  • 왕명안;임경수;박우진;안순신
    • Proceedings of the Korean Information Science Society Conference
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    • 2002.04a
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    • pp.487-489
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    • 2002
  • 최근 무선랜의 편리성으로 인하여 사용자의 수는 크게 증가하고 있는데 반하여 현재 상용되고 있는 무선랜 기술은 사용자의 요구에 대응하지 못하고 있는 실정이다. 본 논문에서는 무선랜의 표준인 IEEE 802.11에서 제안된 DCF(Distributed coordination function)와 PCF(point coordination function)의 두 가지 전송 방식의 성능향상을 위한 방안으로서 신뢰성, 공평성 등의 장점을 가지도록 실시간 데이터 전송방법을 제안한다.

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Coordination of dual arm robot using 3-D vision sensor

  • Yoshioka, Izuru;Taguchi, Nobuyoshi;Yeol, Beak-Ju;Wang, Honbo;Ishimatsu, Takakazu
    • 제어로봇시스템학회:학술대회논문집
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    • 1995.10a
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    • pp.400-403
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    • 1995
  • A robot system is proposed to realize coordinated motion of two arm robot. Due to a 3-D vision sensor, precise coordinated motions could be realized. Using a sophisticated IC chip, real time image processing could be executed using a simple circuit.

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A method of collision-free trajectory planning for two robot arms

  • Lee, Jihong;Bien, Zeungnam
    • 제어로봇시스템학회:학술대회논문집
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    • 1989.10a
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    • pp.649-652
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    • 1989
  • In this paper we outline an approach for the collision-free trajectory planning of two robot arms which are modeled as connected line segments. A new approach to determine the collision between two robot arms and the boundary of the collision region in the coordination space is proposed. The coordination curve may then be chosen to avoid the collision region. For minimum time trajectory, time is assigned to this curve by dynamic time scaling under constraints such as maximum torque or maximum angular velocity of each actuator. A comparison of the proposed method and the graphical method of determining the collision region is also included. Finally, as an example, some simulation results for two SCARA type robots are presented.

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Eye-hand coordination in press task (프레스 작업에서 눈과 손의 협응동작에 대한 연구)

  • 박경수;김유창
    • Journal of the Ergonomics Society of Korea
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    • v.16 no.1
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    • pp.63-71
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    • 1997
  • This paper presented an experiment which examined eye and hand movement characteristics of novice and experienced workers in the press operation. Continuous recordings of eye and hand movements were made on five novice operators and five experienced operators in press operation. Significant difference between the novice and the experienced operators was observed in eye fixation time, eye movement patterns, hand dwell time, and eye-hand coordination. Also, differences were observed in spatial distribution of eye fixations during the die-closing portion of a stroke. There were no significant differences between the novice and the experiencedoperators in the eye and the hand movement time. The results could be used to establish a guide determining the method and training period to train the novice operators.

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A study on Protective Coordination of MCA for Performing of the Pad Mounted Transformer's inside Protective Device (지상변압기의 내부 보호장비 작동을 위한 MCA 보호협조에 대한 연구)

  • Hyun, Seung-Yoon;Kim, Chang-Hwan
    • KEPCO Journal on Electric Power and Energy
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    • v.8 no.1
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    • pp.5-7
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    • 2022
  • KEPCO's plan is undergoing a trial operation to replace the open-loop section with ring main units configuration where underground distribution lines are installed, by linking the multi-way circuit breakers auto (MCA) on the power side of each pad-mounted transformer. However, ring main units application mentioned above may cause the ripple effects, when implementing the configuration without a study of protection coordination. Because ring main units with classical pre-set protection devices contribution in fault condition didn't consider yet. For the reliable ring main units operation, it is necessary to resolve several protection issues such as the protection coordination with substation side, prevention of the transformer inrush current. These issues can radically deteriorate the distribution system reliability Hence, it is essential to design proper protection coordination to reduce these types of problems. This paper presents a scheme of ring main units' configuration and MCA's settings of time-current curves to preserve the performance of protection coordination among the switchgears considering constraints, e.g. prevention of the ripple effects (on the branch section when a transformer failure occurs and the mainline when a branch line failure occurs). It was confirmed that the propagation of the failure for each interrupter segment could be minimized by applying the proposed TCC and the interrupter settings for the MCAs (branch, transformer). Further, it was verified that the undetected area of the distribution automation system (DAS) could be supplemented by having the MCA configurated ring main units operate first, instead of the internal protection equipment in the transformer such as the fuse, STP when a transformer failure occurs.

Correlation of Curved Walking Ability with Straight Walking Ability and Motor Function in Patients with Hemiplegia

  • Lim, Jae-Heon;Park, Jang-Sung;Seo, Sam-Ki
    • The Journal of Korean Physical Therapy
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    • v.23 no.3
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    • pp.13-19
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    • 2011
  • Purpose: In real life there are both straight-paths and curved-paths. To evaluate walking ability of both kinds, a figure-8 walking test (F8WT) was developed. The aim of this study was to validate the measure in hemiplegic patients with walking difficulties and to identify correlations of curved walking ability with straight walking ability, motor function, and walking performance ability. Methods: Twenty subjects participated in this study. Curved walking was measured by a F8WT. Straight walking ability was measured by a 10-meter walking test (10MWT). Dynamic balancea bility was measured by timed up and go (TUG) tests. Walking performance ability was measured using a modified motor assessment scale (MMAS). Motor function was measured by the Fugl-Meyer assessment (FMA) scale. Data were analyzed using Pearson correlation analysis. Linear regression analyses were performed to explore other functional tests in mobility ability by F8WT time, 10MWT (dependent variable). Results: There was a significant positive correlation of F8WT time with 10MWT and TUG. There was a significant negative correlation of F8WT time with MMAS and FMA-coordination. There was a significant positive correlation of 10MWT with TUG. There was a significant negative correlation of 10MWT with MMAS and FMA-coordination. The F8WT time for curved walking ability was attributed to 10MWT for straight walking ability as 94% level of contribution. Conclusion: The results suggest that the F8WT is a good instrument for measuring walking ability because there is a robust correlation of F8WT time with 10MWT, TUG, MMAS, and FMA-coordination in hemiplegic patients who, after stroke, have a mobility deficiency.

A study on Fault Calculation and Coordination of Relays in Distribution System (배전계통의 고장계산 및 보호계전기 협조에 관한 연구)

  • Kim, Jun-Yoen;Nam, Hae-Kon;Kim, Tae-Seoung
    • Proceedings of the KIEE Conference
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    • 1993.11a
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    • pp.16-18
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    • 1993
  • Recently, the scale of distribution system is being enlarged by increasing power demand. When system fault occurs, fault currents and damage power facilities increase, so system stability decreases. Effective prevention of system from fault extention becomes influential as a subject in distribution system operation. In this study, exact settings of relays are obtained from program for fault calculation and coordination of relays in distribution system. In order to make smooth coordination between relays even when power system conditions vary, operation time and sensitivity of relays are optimized. As a result, reliability of distribution system is increased with rapid and exact operation of relays when fault occurs.

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The Application of Fault Current Limiter in 22.9kV KEPCO Grid - The Study of Relay Coordination (22.9kV 한류기 한전 실계통 시험운전 - 보호계전기 보호협조 방안)

  • Park, Kyungwon;Kim, Min Jee;Shin, Chul Ho;Kim, Young-Geun
    • Proceedings of the KIEE Conference
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    • 2015.07a
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    • pp.215-216
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    • 2015
  • The application of fault current limiter(FCL) reduces power system fault current for circuit breaker to operate properly due to reduced fault current. Also FCL reduces through fault current to the power system equipments. But FCL has changed power system parameters for short time, before application the magnitude of register, triggering current and protective relay coordination have to be studied. In this paper we will examine protective relay coordination with FCL. And propose better solution to assist improving of power system operation through the application of FCL.

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Magic Mirror Fashion Coordination System using Kinect (키넥트를 이용한 매직미러 패션코디네이션 시스템)

  • Kim, Cheeyong;Kim, Mi-Ri;Kim, Jong-Chan
    • Journal of Korea Multimedia Society
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    • v.17 no.11
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    • pp.1374-1381
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    • 2014
  • Digital technology With the popularization of computers and IT technology development is causing a dramatic change across the human life. Increase of profit in fashion industry has a significant impact on the overall industry. It has been studied to develop consumer oriented higher value-added fashion products of including clothes using digital technology abroad. In this paper, we propose a system that when user stand in front of display, user can show body captured depth camera look the coordination of a variety of costume and fashion concept through a magic mirror. Using the system, we will satisfy the convenience of user and be used as a way appropriate to clothing shopping in the shortest time. The system will develop personalized fashion content industry enhanced interaction.

Study on Improvement Measures for Prevention and Countermeasure of Chemical Accident (화학사고 예방 및 대책에 대한 개선방안에 관한 연구)

  • Lee, Deok-Jae;Lee, Tae-Hyung;Shin, Chang-Hyun
    • Fire Science and Engineering
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    • v.30 no.5
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    • pp.137-143
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    • 2016
  • The use of chemicals is increasing due to industrial advancement and diversification. In addition, the number of chemical accidents are increasing at the same time. A multifaceted effort in chemical accidents is needed for efficient prevention and countermeasures. This paper presents, under the current Act, a chemical accident case, including the material safety data sheet (MSDS) through the chemical accident prevention and measures for improvement with regard to research.