• 대한전기학회논문지
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• 제43권2호
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• pp.259-267
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• 1994

This paper describes a current control of a single-phase PWM inverter. The proposed PWM inverter utilizes the instantaneous control method which is based on the real-time digital feedback control and the microprocessor-based deadbeat control. The deadbeat current controller is proposed to control the output current regardless of load component variations by the same method as voltage control. That is, in current control, with a very short sampling time and the successive feedback of the output current, the load current is mainly effected by the magnitude of load impedance rather than load component, the load current is mainly effected by the magnitude of load impedance rather than load component. Therefore, by treating the load as an impedance, the system's order is reduced and the instantaneous current control using the proposed deadeat controller is simplified.

• 동아시아식생활학회지
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• 제17권5호
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• pp.719-726
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• 2007

The results of adding citrus to Jeungpyun in order to diversify the kinds of Jeungpyun available as well as enhance the usage of citrus fruits, were assessed in this study. During fermentation pH was reduced carbon dioxide development was lowest in the citron product and then the tangerine, cumquat and control Jeungpyun, respectively. Volume and specific volume of Jeungpyun were highest id the cumquat Jeungpyun. For all the citrus additions, except for the cumquat there were no significant differences when compared to the control. The tangerine product showed the highest redness and yellowness among the types of citrus, fellowed by cumquat, citron, and lemon. In the textural property tests, hardness was highest in the lemon Jeungpyun. Then, less hardness occurred in the order of citron, control, tangerine and the cumquat Jeungpyun was the softest. In the sensory evaluation, preferred color was in the order of tangerine, cumquat citron, and lemon Jeungpyun. Ultimately, the tangerine Jeungpyun had the best color. In the taste test, preferred taste was in the order of cumquat, citron, tangerine, and lemon Jeungpyun, all resulting in better taste than the pure Jeungpyun. The softness of the Jeungpyun was good in the order of cumquat, tangerine, control, citron, and lemon Jeungpyun. Thus, the cumquat Jeungpyun was softest, while lemon Jeungpyun was hardest. Finally, overall acceptance was good in the order of cumquat, tangerine, citron, control, and lemon Jeungpyun.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제51권3호
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• pp.116-124
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• 2002

Design and analysis of disturbance observer-based deadbeat control fur single-phase inverter applications are comprehensively presented in this paper. Load current can be estimated by disturbance observer, which is basically structured with the first order equation in this case and is regarded as a relatively simple method in comparison with conventional full-order Luenberger observer. Also, an inherent one-step delay problem appeared in the deadbeat control method is overcome by a simple prediction technique proposed. Output voltage dip is reduced by the feedforward control with the change rate of the estimated load current involved in the deadbeat current control loop. The proposed algorithms are verified by the respective simulation and experiment results.

• Smart Structures and Systems
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• 제24권1호
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• pp.95-110
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• 2019

The semi-active impact damper (SAID) is proposed to improve the damping efficiency of traditional passive impact dampers. In order to investigate its damping mechanism and vibration control effects on realistic engineering structures, a 20-story nonlinear benchmark building is used as the main structure. The studies on system parameters, including the mass ratio, damping ratio, rigid coefficient, and the intensity of excitation are carried out, and their effects both on linear and nonlinear indexes are evaluated. The damping mechanism is herein further investigated and some suggestions for the design in high-rise buildings are also proposed. To validate the superiority of SAID, an optimal passive particle impact damper ($PID_{opt}$) is also investigated as a control group, in which the parameters of the SAID remain the same, and the optimal parameters of the $PID_{opt}$ are designed by differential evolution algorithm based on a reduced-order model. The numerical simulation shows that the SAID has better control effects than that of the optimized passive particle impact damper, not only for linear indexes (e.g., root mean square response), but also for nonlinear indexes (e.g., component energy consumption and hinge joint curvature).

• Journal of Electrical Engineering and Technology
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• 제12권4호
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• pp.1663-1674
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• 2017

This paper deals with the robust speed regulation of a surface-mounted permanent magnet synchronous motor (SPMSM) that is subject to parametric uncertainties and external disturbances. The proposed approach retains a conventional cascade control configuration composed of an outer-loop speed control module and inner-loop current control modules. Baseline proportional-integral (PI) controllers are designed for nominal modular systems without accounting for the uncertainties to set a desired control performance of the closed-loop system. After studied in both frequency and time domains, a reduced-order proportional-integral observer (PIO), as a modular disturbance observer, is incorporated with each control module to maintain the ideal performance of the modules. Theoretical analysis confirms the desired performance recovery of the augmented system with modular PIOs to the nominal system. Comparative computer simulations and experimental results validate the proposed cascade control method for SPMSM speed regulation.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1995년도 Proceedings of the Korea Automation Control Conference, 10th (KACC); Seoul, Korea; 23-25 Oct. 1995
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• pp.432-435
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• 1995

In this paper a new approach to obtain the solution of the linear-quadratic Gaussian control problem for singularly perturbed discrete-time stochastic systems is proposed. The alogorithm proposed is based on exploring the previous results that the exact solution of the global discrete algebraic Riccati equations is found in terms of the reduced-order pure-slow and pure-fast nonsymmetric continuous-time algebraic Riccati equations and, in addition, the optimal global Kalman filter is decomposed into pure-slow and pure-fast local optimal filters both driven by the system measurements and the system optimal control input. It is shown that the optimal linear-quadratic Gaussian control problem for singularly perturbed linear discrete systems takes the complete decomposition and parallelism between pure-slow and pure-fast filters and controllers.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1993년도 추계학술대회논문집; 반도아카데미, 26 Nov. 1993
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• pp.5-18
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• 1993

This paper reports the recent trends in active vibration control in Japan, especially, based on papers selected in the Proceedings of First International Conference on Motion and Vibration Control (1st MOVIC) held at Yokohama, Japan on Sept.7-11, 1992. Firstly, it classifiers vibration control methods and vibration controllers, especially active dynamic absorbers which are widely used in mechanical and civil engineering. Secondly, it covers basic problems in the control of vibration of flexible structures such as formulating a reduced-order model required for designing vibration controller, proper arranging of sensors and actuators, and preventing of spillover instability. Finally, the practical use of control theories such as LQ control theory, $H^{\infty}$ control theory, neural network theory, and other topics are discussed..

• 동의생리병리학회지
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• 제18권2호
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• pp.484-489
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• 2004

Objective : In order to study the effects of Herba ChelidoniiㆍClematis Florida ThunbㆍChaenomelis Fructus complex herbal acupuncture on anti-inflammation and liver in rats with arthritis induced Freund's complete adjuvant. Method : We performed several experimental items : that is edema value, numbers of WBC. total protein, total bilirrubin, SGOT, SGPT. Result: The change in the right plantar edema shows that Control group was reduced by 0% but, ST group ,Sample A group and Sample B group were reduced by 287.2%, 343.0%, 272.5% respectively. In the WBC count, ST group, Sample A group, Sample B group showed a decrease with statistical significance as compared with control group. In the total protein, Sample B group showed a decrease with statistical significance as compared with control group. In the total bilirrubin, SGOT, SGPT, None showed noxious variation with statistical significance as compared with control group. Conclusion : As a result of this experiment, it is concluded that Herba ChelidoniiㆍClematis Florida ThunbㆍChaenomelis Fructus complex herbal acupuncture showed that therapeutic effect of anti-inflammation in adjuvant arthritis and non-toxic effect of liver.

• 한국의류학회지
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• 제3권2호
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• pp.29-36
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• 1979

In order to control free formaldehyde release from fabric finished with urea-formaldehyde precondensate, the resin finished fabric was padded in urea or acylamide solution, dried and cured at $140^{\circ}C$. The effect of aftertreatment with urea or acrylamide on free formaldehyde release and on characteristics of resin finished fabric were examined. It was shown that aftertreatment with urea was effective to control free formaldehyde release, the free formaldelyde content in aftertreated fabric could be reduced from 900 ppm to 200 ppm and formaldehyde release under accelerated storage condition was also reduced from 8000 ppm to 1000 ppm. Polyacrylamide formed in the fiber during aftertreatment appeared to be a formaldehyde capture. Especially by washing the aftertreated fabric, the ability to control formaldehyde release under accelerated condition was not dimimished in contrast with aftertreated with unea. It suggests that polyacrylamide can be used as a formaldehyde capture which withstand diminution from washing.

• 혜화의학회지
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• 제17권2호
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• pp.137-148
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• 2008

In order to investigate the effects of JHG on immune cells in BALF, clinically prescribed JHG was tested using OVA induced asthma animal model. The results are shown below: 1. JHG significantly reduced the total number of cells in BALF compared to that of the control at 400 mg/kg doses. 2. JHG significantly reduced the number of CD3+/CD69+ cells in BALF at 400 and 200 mg/kg doses. 3. JHG significantly reduced the number of CCR3+ cells in BALF at 400 and 200 mg/kg doses. 4. JHG significantly reduced the number of B220+/CD22+ cells in BALF at 400 and 200 mg/kg doses. 5. JHG significantly reduced the number of B220+/IgE+ cells in BALF at 400 and 200 mg/kg doses. 6. JHG significantly reduced the number of B220+/CD45+ cells in BALF at 400 and 200 mg/kg doses. From the results above, anti-asthmatic efficacy of JHG through anti-oxidative activity as well as immune control activity has been experimentally proven. In depth study of JHG on various pathological factors and individual drug contents of JHG should follow.