• 제목/요약/키워드: Control Function

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Open Loop Responses of Posture Complexity in Biomechanics

  • Shin, Youngkyun;Park, Gu-Bum
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.27 no.8
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    • pp.42-50
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    • 2013
  • The reactionary responses to control human standing dynamics were estimated under the assumption that postural complexity mainly occurs in the mid-sagittal plane. During the experiment, the subject was exposed to continuous horizontal perturbation. The ankle and hip joint rotations of the subject mainly contributed to maintaining standing postural control. The designed mobile platform generated anterior/posterior (AP) motion. Non-predictive random translation was used as input for the system. The mean acceleration generated by the platform was measured as $0.44m/s^2$. The measured data were analyzed in the frequency domain by the coherence function and the frequency response function to estimate its dynamic responses. The significant correlation found between the input and output of the postural control system. The frequency response function revealed prominent resonant peaks within its frequency spectrum and magnitude. Subjects behaved as a non-rigid two link inverted pendulum. The analyzed data are consistent with the outcome hypothesized for this study.

A Survey on the Quality Control System for Manufacturing Industry of Jeon-buk area (전북지역(全北地域) 생산업체(生産業體)의 품질관리(品質管理) 실태(實態)에 관한 조사분석(調査分析))

  • Kim, Yeong-Gyun;Park, Byeong-Gi
    • Journal of Korean Society for Quality Management
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    • v.15 no.1
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    • pp.33-46
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    • 1987
  • The present survey was made through mail questionaires aiming at understanding the conditions of quality control, finding problems and making improvement for manufacturing companies located in the Chonbuk area. The conditions of quality control were compared between KS marking companies and non KS marking companies regardless of manufactured products. The main check points were the function of process control, the function of quality assurance, the function of quality survey, the function of quality system, quality education, quality training, the function of QC circle and general functions excepting the scale of enterprise.

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Switching Control for End Order Nonlinear Systems by Avoiding Singular Manifolds (특이공간 회피에 의한 2차 비선형 시스템의 스위칭 제어기 설계)

  • Yeom, D.H.;Im, K.H.;Choi, J.Y.
    • Proceedings of the KIEE Conference
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    • 2003.11b
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    • pp.315-318
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    • 2003
  • This paper proposes a switching control method applicable to any affine, 2nd order nonlinear system with single input. The key contribution is to develop a control design method which uses a piecewise continuous Lyapunov function non-increasing at every discontinuous point. The proposed design method requires no restrictions except full state availability. To obtain a non-increasing, piecewise continuous Lyapunov function, we change the sign of off-diagonal term s of the positive definite matrix composing the former Lyapunov function according to the sign of the Inter-connection term. And we use the solution of inequalities which guarantee each Lyapunov function is non-increasing at any discontinuous point.

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Torque Control of a Switched Reluctance Motor for the Precision Position Control of a Tank Gun (전차 포신의 정밀 위치 제어를 위한 스위치드 리럭턴스 모터의 토크 제어)

  • 최창환;김용대;이대옥;박기환
    • Journal of the Korea Institute of Military Science and Technology
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    • v.3 no.2
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    • pp.42-52
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    • 2000
  • A torque control method of a switched reluctance motor for the position control of a tank gun is presented. One of the widely used torque control scheme, torque sharing function method, is investigated and a new torque sharing function method is proposed that extends the definition region of the conventional TSF to both the positive and negative torque production regions. By using this definition, all kinds of the control inputs that consider switching on/off angle control as well as the current profiling can be described. A parametrized representation of the current profiles is proposed by using a series of B-spline functions, which reduces memory requirement and enables additional controllers. Optimal determination of the TSFs are also investigated for various control objectives. Moreover, the comparison study of each objective is presented. Since this method generalizes all of the possible control input, the current and torque profiles obtained from the optimization are the most suitable control input that satisfy the objectives.

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The Design and Implementation of the Collision Avoidance Warning Function in the Air Traffic Control System (항공관제 시스템에서 항공기 공중충돌 경고기능의 설계 및 구현)

  • Song, Jin-Oh;Sim, Dong-Sub;Kim, Ki-Hyung
    • Journal of the Korea Institute of Military Science and Technology
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    • v.12 no.2
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    • pp.213-221
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    • 2009
  • An aircraft collision accident is a disaster that causes great losses of inventories and lives. Though a collision avoidance warning function is provided automatically to pilots in the aircrafts by the enhancement of the aircraft capability, achieving fast decision-making to escape a collision situation is a complex and dangerous work for pilots. If an in-flight collision situation is controlled by the air traffic control system which monitors all airplanes in the air, it would be more efficient to prevent in-flight collisions because it can handle the emergency before the pilot's action. In this paper, we develop the collision avoidance warning function in the air traffic control system. Specifically, we design and implement the five stages of the collision avoidance function, and propose a visualization method which could effectively provide the operators with the trajectories and altitudes of the aircrafts in a collision situation. By developing an in-flight collision warning function in the air traffic control system that visualizes flight patterns through the state transition data of in-flight aircrafts on the flight path lines, it can effectively prevent in-flight collisions with traffic alerts. The developed function allows operators to effectively select and control the aircraft in a collision situation by providing the operators with the expected collision time, the relative distance, and the relative altitude while assessing the level of alert, and visualizing the alert information which includes the Attention-Warning-Alert phase via embodying the TCAS standard. With the developed function the air traffic control system could sense an in-flight collision situation before the pilot's decision-making moment.

Regional Control of Vibration (진동의 영역 제어)

  • Kim, Yang-Hann;Chang, Ji-Ho
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2008.04a
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    • pp.472-475
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    • 2008
  • Generally, a linear vibration theory regards a vibratory system as the superposition of many degrees of vibratory system. Modal analysis stems, in fact, considers the vibration system as what has input, output, and transfer function that relates the input and output. When we want to control, however, the vibratory system, we define, first, the object function that can be vibration energy of certain vibratory system. Then, we try to find the transfer function that can minimize the object function. We can readily extend this approach to control the distributed vibration system. For example, the vibrations of a vehicle, including ships and trains. In this case, we may want to minimize the vibration of the area we select. For example, minimize the vibration of the passengers' seat, but allowing the vibration of other area; for example engines and wheels. This paper introduces a general theory that can control the vibration of the selected area, which can be called as "regional control of vibration." In fact, this is the extended theory of well known sound control of "bright zone"(Choi and Kim, 2002).]. Several illustrative examples demonstrate the applicability and properties that are not available if we use modal analysis method.

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Structure and Function of HtrA Family Proteins, the Key Players in Protein Quality Control

  • Kim, Dong-Young;Kim, Kyeong-Kyu
    • BMB Reports
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    • v.38 no.3
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    • pp.266-274
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    • 2005
  • High temperature requirement A (HtrA) and its homologues constitute the HtrA familiy proteins, a group of heat shock-induced serine proteases. Bacterial HtrA proteins perform crucial functions with regard to protein quality control in the periplasmic space, functioning as both molecular chaperones and proteases. In contrast to other bacterial quality control proteins, including ClpXP, ClpAP, and HslUV, HtrA proteins contain no regulatory components or ATP binding domains. Thus, they are commonly referred to as ATP-independent chaperone proteases. Whereas the function of ATP-dependent chaperone-proteases is regulated by ATP hydrolysis, HtrA exhibits a PDZ domain and a temperature-dependent switch mechanism, which effects the change in its function from molecular chaperone to protease. This mechanism is also related to substrate recognition and the fine control of its function. Structural and biochemical analyses of the three HtrA proteins, DegP, DegQ, and DegS, have provided us with clues as to the functional regulation of HtrA proteins, as well as their roles in protein quality control at atomic scales. The objective of this brief review is to discuss some of the recent studies which have been conducted regarding the structure and function of these HtrA proteins, and to compare their roles in the context of protein quality control.

The Effect of Trunk Stability Exercises on Trunk Control Ability and Daily Living Activities on the Osmotic Demyelination Syndrome of a Patient with Hyponatremia -A Case Study- (체간안정화운동이 저나트륨혈증 환자에게 발생한 삼투성 탈수초 증후군에서 체간조절능력과 일상생활동작에 미치는 영향(단일사례연구))

  • Jung, Du-Kyo
    • PNF and Movement
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    • v.12 no.4
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    • pp.249-258
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    • 2014
  • Purpose: This study examines deficits in upper-extremity function and trunk control ability on the osmotic demyelination syndrome of a patient with Hyponatremia and Hypokalemia. Using a proprioceptive neuromuscular facilitation program, this case report aims to describe the effects of trunk stability exercises on trunk control ability, hand function, and daily living activities as well as its effects on the osmotic demyelination syndrome of a patient with Hyponatremia and Hypokalemia. Methods: The patient is a 47-year-old woman with osmotic demyelination syndrome as well as trunk and upper extremity impairment. She participated in this training intervention for four weeks. Results: The patient demonstrated improvements in trunk control ability, hand function, and performance of ADL. The following outcomes were measured before and after the training program: trunk impairment scale, hand power, Jebsen-Taylor hand function test, the Chedoke arm and hand inventory, and the modified Barthel index. Conclusion: The results suggest that trunk stability exercises in the form of a proprioceptive neuromuscular facilitation program in Hyponatremia and Hypokalemia patients may increase trunk control ability, increase hand function, and improve ADL.

Posture Stabilization Control for Mobile Robot using Marker Recognition and Hybrid Visual Servoing (마커인식과 혼합 비주얼 서보잉 기법을 통한 이동로봇의 자세 안정화 제어)

  • Lee, Sung-Goo;Kwon, Ji-Wook;Hong, Suk-Kyo;Chwa, Dong-Kyoung
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.8
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    • pp.1577-1585
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    • 2011
  • This paper proposes a posture stabilization control algorithm for a wheeled mobile robot using hybrid visual servo control method with a position based and an image based visual servoing (PBVS and IBVS). To overcome chattering phenomena which were shown in the previous researches using a simple switching function based on a threshold, the proposed hybrid visual servo control law introduces the fusion function based on a blending function. Then, the chattering problem and rapid motion of the mobile robot can be eliminated. Also, we consider the nonlinearity of the wheeled mobile robot unlike the previous visual servo control laws using linear control methods to improve the performances of the visual servo control law. The proposed posture stabilization control law using hybrid visual servoing is verified by a theoretical analysis and simulation and experimental results.

A Study on the Urban Ecosystem Assessment for 31 Cities & Counties around the Capital (수도권 31개 시·군의 도시생태계 현황 평가에 관한 연구)

  • Sung, Hyun-Chan;Hwang, So-Young
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.15 no.5
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    • pp.165-176
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    • 2012
  • The objective of this study is to set urban ecosystem assessment indicators, assess the status of the urban ecosystems in 31 cities & counties in the capital region and based on which, to examine an improvement plan to resolve problems and raise quality and quantity of urban ecosystems. The study showed that the ecological base of 31 cities & counties was 48% on average, which indicates that their ecological property is the middle class. Their natural-ecological function was 63% and environmental-control function was 25%, showing that environment-control function was poor. Therefore, going forward, urban ecological base should be further improved. When securing an ecological base, creation techniques should be able to further enhance environmental-control function along with natural-ecological function. Also, additional effort should be made to conserve areas with high ecological value as much as possible and increase vegetation vitality by replacing tree species.