• 제어로봇시스템학회논문지
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• 제10권7호
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• pp.590-596
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• 2004

A passivity-based dynamic output feedback controller design is considered for a finite collection of non-square linear systems. Design of a single controller for a set of plants i.e. simultaneous stabilization is an important issue in the area of robust control design. We first determine a squaring gain matrix and an additional dynamics that is connected to the systems in a feedforward way, then a static passivating control law is designed. Consequently, the actual feedback controller will be the static control law combined with the feedforward dynamics. A necessary and sufficient condition for the existence of the parallel feedforward compensator is given by the static output feedback formulation. In contrast to the previous result [1], a technical condition for constructing the parallel feedforward compensator is removed by proposing a new type of the parallel compensator.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 A
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• pp.111-114
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• 2003

In this paper, we consider the stabilization and $H_\infty$ control of linear systems with static output feedback control. The static output feedback control represents the simplest closed-loop control that can be realized in practice, and, moreover, it is less expensive to be implemented and is more reliable. In spite of its advantages, it is one of the open problems which is not sloved analytically or numerically yet. After decompose the closed-loop system into feedback form, by adopting the small gain theorem, we obtain a sufficient condition for stabilization and a sufficient condition for It control expressed as linear matrix inequalites. Finally, we show the usefulness of our results by a numerical example.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2002년도 추계학술대회 논문집(II)
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• pp.884-891
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• 2002

This report is the result performed the structural analysis and the static and fatigue load test of bogie frame for the purpose of designing and verifying the bogie frame which satisfy the load condition required in the UIC code. This investigation is proposed the efficient draft of the design to satisfy the load condition required in the UIC code. And It is performed the structural analysis to evaluate the static strength and the fatigue life of the patient material and the welded part. Also, This is proposed the efficient draft of the test to satisfy the method of the static and fatigue test required in the UC code. And it is carried out the static and the fatigue load test to verify it. We can designed the bogie frame in compliance with UIC 515-4 and 615-4 code.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 학술대회 논문집 정보 및 제어부문
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• pp.523-525
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• 2005

This paper deals with a linear matrix inequality (LMI) approach to the design of a static output feedback controller that simultaneously stabilizes a finite collection of linear time-invariant plants. Simultaneous stabilization by static ouput feedback is represented in terms of LMIs with a rank condition. An iterative penalty method is proposed to solve the rank-constrained LMI problem. Numerical experiments show the effectiveness of the proposed algorithm.

• 항공우주기술
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• 제8권1호
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• pp.73-81
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• 2009

75톤급 터보펌프 개발을 위해 터보펌프 실 부위를 모사한 시험기를 제작하여 3종의 스태틱 실에 대한 상온 및 극저온 환경 기밀시험을 실시하였다. Conical 스태틱 실, PTFE 스태틱 실, C 스태틱 실을 적용한 기밀시험 결과 상온에서 기밀이 유지되더라도 산화제펌프의 이종 소재 사용에 따른 열수축률의 차이로 인해 PTFE 스태틱 실과 C 스태틱 실에서만 극저온 기밀이 유지되었고 Conical 스태틱 실에서는 극저온 기밀 유지에 실패하였다. 이는 기밀 면이 축방향인 PTFE 스태틱 실, C 스태틱 실과는 달리 Conical 스태틱 실의 기밀 면이 반경방향이므로 케이징의 반경방향 수축 시 기밀 면에 틈새가 생기기 때문인 것으로 파악된다. 더욱이 C 스태틱 실은 시험기 분해 후 재사용하여도 극저온 기밀이 유지되는 우수한 특성을 보였다.

• 대한물리의학회지
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• 제7권2호
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• pp.191-197
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• 2012

Purpose : The purpose of this study was to examine immediate effects of 15 minutes plantarflexor static stretching in quite stance. Methods : Twenty-nine subjects were measured static balance during 1 minute in quite stance with eye closed condition before and after 15 minutes plantarflexor static stretching. Static stretching range was limited from $15^{\circ}$ to $20^{\circ}$ dorsiflexion within comfortable range. Results : The result of this study showed that postural sway significantly increased during 1 minute quiet stance after 15 minutes static stretching(p<.05). Before stretching, postural sway significantly decreased during 41-60 seconds compared to 0-20, 21-40 seconds(p<.05). After stretching, postural sway was decreased significantly over time 0-20, 21-40, and 41-60 seconds(p<.05). Conclusion : The prolong plantarflexor static stretching may require biomechanical, neurological adaptations prior to walking or sport activities for safety.

• 소성∙가공
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• 제4권2호
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• pp.169-179
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• 1995

Static restoration mechanism during hot interrupted deformation of Cu-Zn alloy was studied in the temperature range from $550^{\circ}C$ to $750^{\circ}C$ and at a constant strain rate of 0.1/sec. At a given temperature, the hot interrupted deformations were performed with variation of interrupted time $t_i$ form 1 to 50 sec and of interrupted strain ${\varepsilon}_i$ from 0.15 to 0.90. From the analysis of the values of the critical strain of ${\varepsilon}_c$ for tje initiation of dynamic recrystallization and the peak strain of${\varepsilon}_p$, the relationship ${\varepsilon}_c{\fallingdotseq}0.7{\varepsilon}_p$ was obtained. It was clarified that the softening of the interrupted deformation was mainly the static recrystallization and the fractional softening(FS) which was over 30% mostly confirmed this result. The fractional softening of the interrupted time $t_i$ especially and pre-strain. The FS increased with increasing strain rate, interrupted time and pre-strain. The change of microstructures after hot deformation could be predicted by the FS. when the FS was 30~100%, static recrystallization was happened and grain growth was observed at the condition which was $750^{\circ}C$ deformation temperature, 0.45 prestrain and this condition's FS value was over 100%.

• International Journal of Control, Automation, and Systems
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• 제3권3호
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• pp.430-443
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• 2005

A general construction algorithm of the Grassmann space parameters in linear systems - so-called, the Plucker matrix, 'L' in m-input, p-output, n-th order static output feedback systems and the Plucker matrix, $'L^{aug}'$ in augmented (m+d)-input, (p+d)-output, (n+d)-th order static output feedback systems - is presented for numerical checking of necessary conditions of complete static and complete minimum d-th order dynamic output feedback pole-assignments, respectively, and also for discernment of deterministic computation condition of their pole-assignable real solutions. Through the construction of L, it is shown that certain generically pole-assignable strictly proper mp > n system is actually none pole-assignable over any (real and complex) output feedbacks, by intrinsic rank deficiency of some submatrix of L. And it is also concretely illustrated that this none pole-assignable mp > n system by static output feedback can be arbitrary pole-assignable system via minimum d-th order dynamic output feedback, which is constructed by deterministic computation under full­rank of some submatrix of $L^{aug}$.

• The Journal of Korean Physical Therapy
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• 제33권1호
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• pp.1-6
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• 2021

Purpose: This study examined the effects of heel insoles on the static balance and leg muscle activity and posture control strategy during external perturbation. Methods: Thirty healthy young men participated in the study. The subjects underwent two experimental conditions: 1) no heel insole condition (0cm) and 2) wearing heel insole condition (5cm). The static balance was measured using an I-Balance device, which measured the change in the center of gravity (COG). The onset time of muscle activation and muscle activation of the erector spinae (ES), hamstring (HAM), gastrocnemius (GCM) were measured using surface EMG electrodes to determine the change in posture control strategy during external perturbation. Results: The speed and distance of COG were significantly higher in the wearing heel insoles condition than the no heel insole condition (p<0.05). In addition, significant differences in the onset time of the GCM, HAM, and ES muscle activation were observed when there was no heel insole condition during external perturbation (p<0.017). On the other hand, no significant differences in the onset time of muscle activation were observed between GCM and HAM when wearing the heel insole condition during external perturbation (p<0.017). Moreover, muscle activation of the GCM was significantly higher in the wearing heel insoles condition than the no heel insole condition during external perturbation (p<0.05). Conclusion: These findings suggest that heel insoles may have disadvantages, and increased efforts are needed to maintain balance and change the posture control strategy during external perturbation.

• 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.