• Title/Summary/Keyword: Control Technique

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Development of a Solenoid Control Technique for the Suppression of Brake System Noise and Vibrations of the Elevator Traction Machine (엘리베이터 권상기 브레이크 시스템 소음 및 진동 감소를 위한 솔레노이드 구동 제어기법 개발)

  • Yang, Dong-Ho;Kim, Ki-Young;Heo, Seok;Kwak, Moon-K.;Lee, Jae-Ha
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2012.04a
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    • pp.65-71
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    • 2012
  • This paper is concerned with the suppression of brake system noise and vibrations of the elevator traction machine by means of a solenoid control technique. The solenoid is used to hold the brake shoe, which is then released by turning the solenoid off. Since the brake shoe hits the brake disk, vibrations and noise occur. We develop the solenoid control technique based on the dynamic behavior of the solenoid. The theoretical model for the solenoid is modeled by using linear magnetic principles. The solenoid model was then combined with the vibration model to simulate the brake system vibrations. The simulation results show that the additional pulse input to the solenoid can decrease the vibrations. The timing of the applied pulse is determined by observing the current. The experimental results show that both the vibrations and noise can be substantially decreased, which validates the approach developed in this paper.

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The Efficacy of Sacro-Occipital Technique for Stroke Patients on Activity of Daily Living (ADL), Leg Function.Balance (Sacro-Occipital Technique이 중풍 환자의 일상생활동작, 하지기능.균형에 미치는 효과)

  • Kwon, Oh-Gon;Kim, Min-Su;Ahn, Hee-Duk;Woo, Chang-Hoon
    • The Journal of Churna Manual Medicine for Spine and Nerves
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    • v.2 no.2
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    • pp.57-68
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    • 2007
  • Objectives : The purpose of this study is to investigate the efficacy of Sacro-Occipital Technique with stroke on activity of daily living(ADL), leg function balance. Methods : Sacro-Occipital Technique at pelvic girdle was applied to six stroke-originated hemiplegic patients who had been treated by general oriental medicine rehabilitation therapy(sample group). The other five stroke-originated hemiplegic patients had only general oriental medicine rehabilitation therapy(control group). Outcomes were assessed by Modified Barthel Index(MBI), Berg Balance Scale(BBS) before and after treatment in each group. Results : Both sample and control group exhibited substantial improvements on the MBI and BBS. And BBS showed significantly meaningful differences between sample and control group. Conclusions : Sacro-Occipital Technique may be efficacious method of improving ADL, leg function balance of patients after stroke.

Can Myofascial Release Techniques Reduce Stress Hormones in the Subject of Short Hamstring Syndrome? A Pilot Study

  • Cho, Sunghak
    • Journal of International Academy of Physical Therapy Research
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    • v.11 no.4
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    • pp.2237-2243
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    • 2020
  • Background: The myofascial release technique is known to be an effective technique for increasing posterior fascia flexibility in short hamstring syndrome (SHS) subjects. But therapeutic mechanism of myofascial relaxation remains unclear. Recently, the theory of autonomic nervous system domination has been raised, however, a proper study to test the theory has not been conducted. Objectives: To investigate whether the application of the myofascial release technique can induce changes in the autonomic nervous system and affect the secretion of stress hormones and myofascial relaxation. Design: Quasi-experimental study. Methods: Twenty-four subjects with SHS were randomly divided into two groups. In the experimental group, the suboccipital muscle inhibition (SMI) technique was applied to the subjects for 4 min in supine position, and in the control group, the subjects were lying in the supine position only. A forward flexion distance (FFD) was conducted, blood pressure, heart rate, and cortisol levels were measured before and after the intervention and 30 min after intervention to determine myofascial relaxation and stress hormone levels. The evaluation was conducted separately in blind by an evaluator. Results: A FFD decreased in the experimental group, no change in cortisol was observed. On the contrary, a decrease in cortisol appeared in the control group after 30 minutes. Conclusion: The myofascial release technique is an effective treatment to increase the range of motion through posterior superior myofascial chain, but there is no evidence that myofascial release technique can control the autonomic nervous system.

A Study on Motion Control and Kinematics Analysis of Articulated Manipulator Attachment for Excavator (포크레인용 다관절 매니퓰레이터 어태치먼트 운동학 해석 및 모션제어)

  • Kim, Hee-Jin;Kim, Sang-Hyun;Jang, Ki-Won;Han, Sung-Hyun
    • Journal of the Korean Society of Industry Convergence
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    • v.22 no.6
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    • pp.807-819
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    • 2019
  • In this paper, it is proposed a new approach to motion control and kinematics analysis of articulated manipulator attachment with five degree of freedom for excavator. Unlike the well-established theory for the control of linear systems, there is little general control theory relatively for a robust control of nonlinear systems. The control technique is essential for providing a stable and robust performance for application of articulated manipulator control. The proposed control algorithm is one of robust control methods based on error informations of the position and velocity error informations using stability analysis of dynamic model. Through simulation test, the proposed control scheme is illustrated to be a efficient control technique for real-time control.

Optimal Displacement Control of Shear Wall Structure using Sensitivity Analysis Technique (감도해석기법을 이용한 전단벽 구조물의 최적변위제어)

  • Lee Han-Joo;Jung Sung-Jin;Kim Ho-Soo
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2005.04a
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    • pp.121-128
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    • 2005
  • This study presents an effective stiffness-based optimal technique to control quantitatively lateral drift for shear wall structures subject to lateral loads. To this end the displacement sensitivity depending on behavior characteristics of shear wall structures is established. Also, the approximation concept that can preserve the generality of the mathematical programming and can efficiently solve large scale problems is introduced. Resizing sections in the stiffness-based optimal design are assumed to be uniformly varying in size and the technique of member grouping is considered for the improvement of construction efficiency Two types of 11-story shear wall structures are presented to illustrate the features of the quantitative lateral drift control technique proposed in this study.

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Reliability Analysis of Interleaved Memory with a Scrubbing Technique (인터리빙 구조를 갖는 메모리의 스크러빙 기법 적용에 따른 신뢰도 해석)

  • Ryu, Sang-Moon
    • Journal of Institute of Control, Robotics and Systems
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    • v.20 no.4
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    • pp.443-448
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    • 2014
  • Soft errors in memory devices that caused by radiation are the main threat from a reliability point of view. This threat can be commonly overcome with the combination of SEC (Single-Error Correction) codes and scrubbing technique. The interleaving architecture can give memory devices the ability of tolerating these soft errors, especially against multiple-bit soft errors. And the interleaving distance plays a key role in building the tolerance against multiple-bit soft errors. This paper proposes a reliability model of an interleaved memory device which suffers from multiple-bit soft errors and are protected by a combination of SEC code and scrubbing. The proposed model shows how the interleaving distance works to improve the reliability and can be used to make a decision in determining optimal scrubbing technique to meet the demands in reliability.

Field Inspection of Phase-Array Ultrasonic for PolyEthylene Electrofusion Joints

  • Kil, Seong-Hee;Jo, Young-Do;Yoon, Kee-Bong
    • Journal of the Korean Institute of Gas
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    • v.16 no.1
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    • pp.22-25
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    • 2012
  • Welding and/or fusion in polyethylene(PE) system made on site is focused on the control of the welding or fusion process to follow proper procedure. The process control is important, but it is not sufficient for the long term reliability of a pipe system. To achieve the rate of failure close to zero, Non Destructive Testing(NDT) is necessary in addition to joining process control. For electrofusion joints several non-destructive testing methods are available. The ultrasonic phased array technique is possible to detect various defects including wire deviations and regions with lack of fusion. In this studies, testing was carried to detect the defect after electrofusion joining of polyethylene piping is utilized by the ultrasonic phased array technique. From testing data, ultrasonic phased array technique is recommended as a reliable non-destructive testing method.

A study on the Hough Transform by using Multi-Resolution technique (다 해상도 기법에 의한 Hough 변환에 관한 연구)

  • Kim, Han-Young;Youn, Sei-Jin;Woo, Dong-Min
    • Proceedings of the KIEE Conference
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    • 1998.07g
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    • pp.2234-2236
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    • 1998
  • In this paper, we propose a new algorithm based on multi-resolution application of the parameter space to the Hough transform technique. The existing Hough transform technique employs mapping of fixed parameter space in order to extract straight lines from image. One of the difficulties of the existing Hough transform technique lies in the detection of multiple adjacent lines for only one line. Increasing the parameter space from the low level resolution to the high level resolution, our algorithm detects straight line in a stable and efficient fashion. Experimental results are included to verity the performance of proposed algorithm.

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Controlled-Type ZVS Technique without Auxiliary Components for Micro-inverters

  • Zhang, Qian;Zhang, Dehua;Hu, Haibing;Shen, John;Batarseh, Issa
    • Journal of Power Electronics
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    • v.13 no.6
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    • pp.919-927
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    • 2013
  • This paper proposes a Boundary Current Mode (BCM) control scheme to realize soft switching on a conventional single phase full bridge DC/AC inverter. This technique with the advantages of no auxiliary components, low cost, high efficiency, and simple in control, is attractive for micro-inverter applications. The operation principle and characteristic waveforms of the proposed soft switching technique are analyzed in theory. A digital controller is provided based on that theory. To balance the requirements of efficiency, switching frequency, and inductor size, the design considerations are discussed in detail to guide in BCM inverter construction. A 150W prototype is built under these guidelines to implement the BCM control scheme. Simulation and experiment results demonstrate the feasibilities of the proposed soft switching technique.

CONCURRENT SIMULATION TECHNIQUE USING THE PROPORTIONAL RELATION FOR THRESHOLD-TYPE ADMISSION CONTROL

  • Ishizaki, Fumio
    • Proceedings of the Korea Society for Simulation Conference
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    • 2001.10a
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    • pp.396-402
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    • 2001
  • In various applications of queueing systems, admission control is often employed. It is known that the threshold-type of admission control is optimal in many practical applications despite its simplicity. However, determining the optimal threshold value is hard in general, because analytical expressions for the stationary queue length distributions are not easily available in most queueing systems. In this paper, to quickly determine the optimal threshold value under threshold-type admission control, we develop a concurrent simulation technique, which can save large amount of CPU time required in simulation, compared to the standard simulation procedure.

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