• 전기의세계
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• 제31권1호
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• pp.59-67
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• 1982

This paper suggests easy stabilization methods for linear time-varying systems with delay in the state. While existing methods employ the function space concept, the methods introduced in this paper transform the delay systems into the non-delay systems so that the well known methods for finite dimensional systems can be utilized. Particularly the intervalwise predictor is introduced and shown to satisfy an ordinary system. Control laws stabilizing the non-delay systems satisfied by this predictor will be shown to at least pointwise stabilize the delay systems with the additional strong possibility of true stabilization. In order to combine two steps of the predictor method, first transformation and then stabilization, an intervalwise regulator problem is suggested whose optimal control laws incorporate the intervalwise predictor as an integral part and also at least pointwise stabilize the delay systems. Since the above mentioned methods render the periodic feedback gains for time invariant systems the pointwise predictor and regulator are introduced in order to obtain the constant feedback gains, with additional stability properties. The control laws given in this paper are perhaps simplest and easiest to implement.

• 전기학회논문지
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• 제66권1호
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• pp.127-136
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• 2017

This paper investigates improved stability and stabilization criteria for sampled-data control systems. By using a suitable and newly constructed augmented Lyapunov-Krasovskii functional and some recent mathematic techniques such as auxiliary function-based integral inequalities, sufficient conditions for stability and stabilization conditions are derived within the framework of linear matrix inequalities(LMI) form. The superiority and validity of the proposed results are illustrated by three numerical examples.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제12권3호
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• pp.187-192
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• 2012

This paper is concerned with stabilization problem of continuous-time Takagi-Sugeno fuzzy systems. To do this, the stabilization problem is investigated based on the new fuzzy Lyapunov functions (NFLFs). The NFLFs depend on not only the fuzzy weighting functions but also their first-time derivatives. The stabilization conditions are derived in terms of linear matrix inequalities (LMIs) which can be solved easily by the Matlab LMI Toolbox. Simulation examples are given to illustrate the effectiveness of this method.

• 한국군사과학기술학회지
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• 제26권1호
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• pp.72-82
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• 2023

The EOTS(Electro Optical Tracking System) must have stabilization performance to provide high-quality images under disturbance environment. In this paper, we present a controller that can minimize the LOS error and has a simple structure. Hence, to evaluate the performance of this controller, analysis in the frequency domain and LOS error measurement are performed. In order to measure the LOS error without a 'rate table' that requires a lot of facility investment, we propose a design method for disturbance model that considers the operating environment of the EOTS. Finally, the performance of the stabilization algorithm is evaluated by the proposed disturbance model.

• 한국재료학회지
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• 제20권2호
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• pp.82-89
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• 2010

Benzotriazole (B.T.A) which has been mainly used for the stabilization processing method of excavated copper and bronze artifacts is vaporized within 2~3 years after the usage because it is unstable at the acid conditions and cannot protect the surface of artifacts. In this study, NaOH method which has been used for the steel artifacts was applied as a stabilization process for the method of copper and bronze artifacts to gush chlorine ion out. For the reproduction of excavated samples, copper and bronze plates were dipped in 0.1M HCl for 26 hrs to form CuCl, rusted at $70^{\circ}C$ with RH 75% for the formation of corrosion products, and desalted in 0.1 M NaOH solution. The concentration of chlorine ion was measured by using ionchromatography. During the desalting process, a large quantity of chlorine ions was gushed out in early period and corrosion products were not additionally generated through the re-corrosion experiment. This NaOH desalting process was found to be a method of stabilization process for copper and bronze artifacts from the formation of Tenorite (CuO) during desalting as a protection layer for corrosion.

• 반도체디스플레이기술학회지
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• 제13권1호
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• pp.27-33
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• 2014

Video from unmanned aerial vehicle (UAV) is influenced by natural environments due to the light-weight UAV, specifically by winds. Thus UAV's shaking movements make the video shaking. Objective of this paper is making a stabilized video by removing shakiness of video acquired by UAV. Stabilizer estimates camera's motion from calculation of optical flow between two successive frames. Estimated camera's movements have intended movements as well as unintended movements of shaking. Unintended movements are eliminated by smoothing process. Experimental results showed that our proposed method performs almost as good as the other off-line based stabilizer. However estimation of camera's movements, i.e., calculation of optical flow, becomes a bottleneck to the real-time stabilization. To solve this problem, we make parallel stabilizer making average 30 frames per second of stabilized video. Our proposed method can be used for the video acquired by UAV and also for the shaking video from non-professional users. The proposed method can also be used in any other fields which require object tracking, or accurate image analysis/representation.

• 대한통합의학회지
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• 제3권2호
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• pp.47-54
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• 2015

Purpose: This study was to investigate the effects of lumbar stabilization exercise and lower extremity strengthening program on pain, lower extremity muscle in patients with chronic low back pain. Method: The subject were randomly divided two groups. 15 people who were conducted lower extremity exercises and lumbar stabilization exercises called the combined exercise group and other(15 people) who were only conducted lower extremity exercise group. The assessment tools were the pain level and the led muscle power. Exercise was conducted for eight weeks. Result: Pain of the combined exercise group showed significant differences in the change in pain level(p<.05). The leg muscle power showed significant differences within group which hip flexor, extensor muscles and abductor muscles. there were significant differences within combined exercise group (p<.05). But the knee joint in each group showed a significant difference within group (p<.05). Conclusion: This study suggest that the lumbar stabilization exercises and lower extremity exercises showed more efficient results in the pain levels and leg muscles power than only the lower extremity exercise for patients with lumbar instability.

• 대한통합의학회지
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• 제2권3호
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• pp.39-48
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• 2014

Purpose : The purpose of this study was to identify the effect of lumbar stabilization exercise (LSE) and isometric lumbar strengthening exercise (ILSE) on lumbar strength and lumbar extension range in healthy young adults. Method : Ten healthy young adults (six males and four females) volunteered to carry out the LSE and ILSE program for two weeks. The subjects were randomly allocated to two groups: the LSE group (n=5) and the LSE plus ILSE group (n=5). The LSE consisted of 20 minutes of exercise related to lumbar stabilization, and the ILSE was composed of five minutes of isometric stabilization exercise with a specific device. Each group exercised three times per week for two weeks. Assessment tools were made using the subjects' isometric lumbar strength and lumbar extension range before and after the interventions. Results : Statistical analysis revealed significant differences in isometric lumbar strength and the lumbar extension range between before and after the interventions in each group (p<.05). Also, the lumbar extension range improved significantly in the LSE plus ILSE group compared to the LSE group; however, there was no statistically significant difference in the two groups' isometric lumbar strength (p>.05). Conclusion : The findings suggest that ILSE might be feasible in clinical settings by offering benefits for lumbar function. Future studies will be continued.

• 대한정형도수물리치료학회지
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• 제22권1호
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• pp.1-7
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• 2016

Background: The purpose of this study was to investigate the effects of lumbar stabilization exercise with neurodynamic techniques on lumbar muscular strength and Oswestry index in lumbar disc herniation patient. Method: The Lumbar stabilization exercise with neurodynamic techniques was performed by 30 pt's in G hospital. The subjects were randomly organized into a study group 15 and control group 15. The exercises and neurodynamic technique were conducted for 40 minutes and, 3 times a week (total 24 times for 8 weeks). General characteristics of the Lumbar muscular strength and Oswestry disability index (ODI) were measured before the training and at 4 weeks and 8 weeks after the intervention. Comparison of the time dependent variable for each group was Calculated by a one way repeated analysis of variance (ANOVA). Comparison between the two groups was Calculated by an analysis of covariance (ANCOVA). Result: There was a significant difference in the Lumbar muscular strength and ODI (p<.05). Similarly in the inter-group analysis, significant differences (p<.05) occurred. Conclusion: In this study, we demonstrated that lumbar stabilization exercises with neurodynamic techniques are an effective therapy for Lumbar muscular strength and ODI in lumbar disc herniation patient's.

• 전자공학회논문지SC
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• 제46권3호
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• pp.15-21
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• 2009

본 논문에서는 변수 불확실성을 가지는 이산시간 특이시스템의 강인 안정화 기법과 강인 보장비용 제어기법을 다룬다. 제안하는 제어기법은 제어기 존재조건에서 준정부호조건(semi-definite condition)이나 시스템 행렬의 분해 없이 볼록최적화(convex optimization)가 가능한 선형행렬부등식 접근방법을 이용하여 제안한다. 먼저, 강인 안정화 상태궤환 제어기는 폐루프 시스템의 정규성, 코잘 및 안정화를 만족하는 제어기의 존재조건과 설계방법을 선형행렬부등식으로 제시한다. 그리고 보장비용 함수의 상한치의 최소화를 보장하는 강인 보장비용 제어기 설계방법은 강인 안정화 제어기 설계를 기반으로 제안한다. 예제를 통하여 제안한 제어기 설계기법의 타당성을 확인한다