• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.95.2-95
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• 2001

Disturbance observer(DOB) based controller design is one of the most popular methods in the field of motion control. In this paper, a generalized disturbance compensation framework, called as robust internal-loop compensator(RIC) is introduced and an advanced design method of DOB is proposed based on the RIC. Mixed sensitivity optimization problem, which is the main issue of DOB design, is solved through the parameterization of DOB in the RIC framework. Different from conventional methods, Q-filter is separated in the mixed sensitivity optimization problem and the systematic design law for the DOB is proposed. This guarantees the robustness and optimality of the DOB and also enables the design for unstable plants.

• Journal of Korean Medicine Rehabilitation
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• v.21 no.4
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• pp.219-226
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• 2011

Objectives: The aim of this pilot study is to investigate qigong as a trailing method to treat diseases and improve the quality of life. Methods: We used a controlled clinical study in this research qigong group(n=34) practiced the zhan zhuang gong for 2 minutes. Control group(n=33) did low intensity walking for 2 minutes. Changes of grip strength, heat rate and rating of perceieved exertion were measured before and after treatment. Paired t-tests and independent t-tests were applied for statistical analysis. Results: Qigong group showed significant improvement in grip strength(p<0.05), whereas the control group showed insignificant changes(p<0.05). Both groups demonstrate significant changes in heart rate(p<0.05). In rating of perceieved exertion, significant difference showed between groups(p<0.05). Conclusions: The zhan zhuang gong, a kind of qigong improved grip strength by 2 minutes of practice. We may conclude that zhan zhuang gong could be a method of improving physical strength.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.42 no.3 s.303
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• pp.11-16
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• 2005

This paper proposed a new IMC-PID controller design method using the loop shaping method. By the application of the loop shaping method for IMC-PID controller which has only one design parameter and guarantees internal stability, we can not only consider such design specifications as gain margin, phases margin, and sensitivity functions but also obtain the loop gain by setting up the relationships between design specifications and design parameters. A systematic method to select design parameters of IMC-PID controller in order to meet the design specifications is suggested and its effectiveness is examined by the case study and analysis.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.41 no.9
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• pp.1071-1084
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• 1992

In this paper, the method for navigation and obstacle avoidance of the autonomous mobile robot is proposed. The proposed algorithms are based on the fuzzy inference system which is able to deal with imprecise and uncertain information. The self-tuning algorithm, which adopts the simplex method, modifies the parameters of membership functions of the input-output linguistic variables by changing the support of these fuzzy sets according to the integral of absolute error(IAE) of the system response. The wall-follwing navigation and obstacle avoidance of the mobile robot are based on range data measured from the internal sensors(encoder) and the outer sensors(sonar sensor). In addition, the algorithm for the obstacle detection proposed in this paper is based on the expert's experience. Finally, the effectiveness of navigation and obstacle avoidance algorithm is demonstrated through simulation and experiment.

• Journal of Institute of Control, Robotics and Systems
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• v.11 no.12
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• pp.1062-1067
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• 2005

This paper discusses a skeleton feature extraction method for ubiquitous robot system. The skeleton features are used to analyze human motion and pose estimation. In different conventional feature extraction environment, the ubiquitous robot system requires more robust feature extraction method because it has internal vibration and low image quality. The new hybrid silhouette extraction method and adaptive skeleton model are proposed to overcome this constrained environment. The skin color is used to extract more sophisticated feature points. Finally, the experimental results show the superiority of the proposed method.

• The Journal of Korea Robotics Society
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• v.7 no.4
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• pp.231-242
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• 2012

This paper proposes particle filter(PF) method using acoustic signal for localization of an underwater robot. The method uses time of arrival(TOA) or time difference of arrival(TDOA) of acoustic signals from beacons whose locations are known. An experiment in towing tank uses TOA information. Simulation uses TDOA information and it reveals dependency of the localization performance on the uncertainty of robot motion and senor data. Also, comparison of the PF method with the least squares method of spherical interpolation(SI) and spherical intersection(SX) is provided. Since PF uses TOA or TDOA which comes from measurement of external information as well as internal motion information, its estimation is more accurate and robust to the sensor and motion uncertainty than the least squares methods.

• Journal of Haehwa Medicine
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• v.17 no.2
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• pp.117-135
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• 2008

In order to investigate the efficacy of a combination of JBB as topical and HTGMB as internal treatment method, changes in various immune related factors and histological changes in NC/Nga induced animal model was studied. Combined treatment of topical JBB and internal HTGMB significantly reduced the atopic dermatitis clinical index, the number of immune cells such as CD19+, CCR3+, B220+/IgE+, and Gr-1+/CD11b+ in DLN and dorsal skin, compared to the control group. Otherwise increased CD3+, CD4+/CD25+, CD8+ and CD4+ cells in the DLN. And also combined treatment of topical JBB and internal HTGMB suppressed the lymphocytes and mast cells from infiltrating into the skin tissues when stained with H&E and toluidine blue. Based on the results above, it is strongly suggested that the combined treatment of topical JBB and internal HTGMB significantly induced anti-allergic activities through immune modulation. The findings can be applied to developing a more sustainable treatment for atopic dermatitis and be helpful in practicing combined treatments in clinical treatments in the future.

• Journal of Haehwa Medicine
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• v.11 no.1
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• pp.91-101
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• 2002

According to the literature on the, the results were as follows. 1. The mechanism of External therapy for prostatitis is some medicicne to come into prostate have anti-inframation and the other medicine to come into nerve system control pain. 2. For the method are uesed hip bath, enema and sticking the pacth to the umbilicus etc. 3. For the medicine are used safflower(紅花), patrinia(敗醫草), chrysanthemum flower(菊花) and Cortex Phellodendri(黃栢). nature and flavor of the medicine is almost cold, bitter in taste and hot in taste. 4. For the classification of medicine are used drug to induce diuresis to elominate stranguria(利尿通淋藥) and drug to induce diuresis to dispersing swelling(利水退腫藥). sometimes they are used to Heat-clearing and detoxifying drug(淸熱解毒藥) and blood-quickening aget(活血祛瘀藥).

• Structural Engineering and Mechanics
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• v.85 no.6
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• pp.809-823
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• 2023

In this work, dynamic stability analysis of the ball after contacting with the earth in the volleyball game is presented. Via spherical shell coordinate, the governing equations and general boundary conditions of the ball after contacting with the earth in the volleyball game is studied. Via Comsol multi-physics simulation, some results are presented and a verification between the outcomes is studied. Harmonic differential quadrature method (HDQM) is utilized to solve the dynamic equations with the aid of boundary nodes of the current spherical shell structure. Finally, the results demonstrated that thickness, mass of the ball and internal pressure of the ball alters the frequency response of the structure. One important results of this study is influence of the internal pressure. Higher internal pressure causes lower frequency and hence reduces the stability of the ball.

• Journal of the Semiconductor & Display Technology
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• v.23 no.2
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• pp.50-54
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• 2024

In this paper, we propose a theoretical method to systematically analyze the power conversion efficiency of a single-phase PFC switching rectifier. Boost-type PFC was organized in order of highest correlation with load current using steady-state analysis results and introduced the concept of loss factor. The loss factors for each major element are summarized and presented in a table. This paper makes it easier to understand the internal loss and power conversion efficiency of the rectifier for loss factors. Lastly, to confirm the validity of the efficiency analysis results reflecting the loss factors, loss and efficiency analysis of the 2.5kW PFC rectifier was performed. The results were compared with data from a 2.5kW PFC circuit for evaluation. As a result, the usefulness of power conversion efficiency analysis reflecting the loss factors proposed in this paper was confirmed.