• 전력전자학회논문지
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• 제3권4호
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• pp.338-345
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• 1998

The mathematical interpretation of a practical sampler which is useful to obtain the small signal models for the peak and average current mode controls is proposed. Due to the difficulties in applying the Shannons sampling theorem to the analysis of sampling effects embedded in the current mode control, several different approaches have been reported. However, these approaches require the information of the inductor current in a discrete expression, which restricts the application of the reported method only to the peak current mode control. In this paper, the mathematical expressions of sampling effects on a current loop which can directly apply the Shannons sampling theorem are newly proposed, and applied to the modeling of the peak current mode control. By the newly derived models of a practial smapler, the models in a discrete time domain and a continuous time domain are obtained. It is expected that the derived models are useful for the control loop design of power supplies. The effectiveness of the derived models are verified through the simulation and experimental results.

• 대한한방내과학회지
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• 제15권1호
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• pp.227-237
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• 1994

These studies were carried out to investigate the effects of Ohotang water extract on the inhibitory contractile action of acetylcholine in control rat. The results of these were as follows; 1. Contractile force of acetylcholine from trachea smooth muscle in control rat was significantly inhibited by Ohotang. 2. Dose-response of acetylcholine pretreated Ohotang in control rat was significantly inhibited. 3. Inhibitory contractile action of acetylcholine pretreated propranolol in control rat was significantly inhibited by Ohotang. 4. Contractile force of acetylcholine pretreated indomethacin from trachea smooth muscle in control rat was not significantly changed. 5. Inhibitory contractile action of acetylcholine pretreated methylene blue in control rat was not significantly changed.

• Smart Structures and Systems
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• 제1권3호
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• pp.283-308
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• 2005

This paper features about the modeling and design of a fast output sampling feedback controller for a smart Timoshenko beam system for a SISO case by considering the first 3 vibratory modes. The beam structure is modeled in state space form using FEM technique and the Timoshenko beam theory by dividing the beam into 4 finite elements and placing the piezoelectric sensor/actuator at one location as a collocated pair, i.e., as surface mounted sensor/actuator, say, at FE position 2. State space models are developed for various aspect ratios by considering the shear effects and the axial displacements. The effects of changing the aspect ratio on the master structure is observed and the performance of the designed FOS controller on the beam system is evaluated for vibration control.

• 제어로봇시스템학회논문지
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• 제16권1호
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• pp.5-11
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• 2010

An adaptive formation control approach is proposed for nonhonolomic multiple mobile robots considering unknown slipping and skidding. It is assumed that unknown slipping and skidding effects are bounded by unknown constants. Under this assumption, the adaptive technique is employed to estimate the bounds of unknown slipping and skidding effects of each mobile robot. To deal with the skidding effect included in kinematics, the dynamic surface design approach is applied to design a local controller for each mobile robot. Using Lyapunov stability theorem, the adaptation laws for tuning bounds of slipping and skidding are induced and it is proved that all signals of the closed-loop system are bounded and the tracking errors and the synchronization errors of the path parameters converge to an adjustable neighborhood of the origin. Finally, simulation results are provided to verify the effectiveness of the proposed approach.

• 아동학회지
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• 제36권5호
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• pp.59-74
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• 2015

The purpose of this study was to examine effects of self-control and social support (e.g., parents, peer, teachers) on bullying victimization and perpetration among early adolescents. 377 youths (11-14 years of age) from elementary and middle schools participated in the study. The data from these subjects were analyzed using the SPSS 18.0. The results of this study may be summarized as follows. There were differences by gender on bullying victimization and perpetration. Among boys, the factors influencing bullying victimization were social support from close friends and self-control. Among girls, the factors influencing bullying victimization were social support from parents and self-control. The factor influencing bullying perpetration was self-control for both boys and girls.

• 국제초고층학회논문집
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• 제2권2호
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• pp.141-152
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• 2013

This paper presents a brief overview of the recently developed performance-control method of moment frame design subjected to monotonously increasing lateral loading. The final product of any elastic-plastic analysis is a nonlinear loaddisplacement diagram associated with a progressive failure mechanism, which may or may not be as desirable as expected. Analytically derived failure mechanisms may include such undesirable features as soft story failure, partial failure modes, overcollapse, etc. The problem is compounded if any kind of performance control, e.g., drift optimization, material savings or integrity assessment is also involved. However, there is no reason why the process can not be reversed by first selecting a desirable collapse mechanism, then working backwards to select members that would lead to the desired outcome. This article provides an overview of the newly developed Performance control methodology of design for lateral resisting frameworks with a view towards integrity control and prevention of premature failure due to propagation of plasticity and progressive P-delta effects.

• 가정과삶의질연구
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• 제28권6호
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• pp.47-57
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• 2010

This study examines the effects of parental variable(parental support and supervision), temperament(activity level, attention span/persistence, and emotionality) and the internal locus of control on self-regulation of children. Data were collected from 455 5th and 6th graders and analyzed with Pearson's correlations and pathway analysis. The results were as follows : Children's temperament, internal locus of control and parental variable directly affected children's self-regulation. Parental variables mediated between children's temperament and internal locus of control and self-regulation. Internal locus of control mediated between children's temperament and self-regulation: in addition, the most important variable predicting children's self-regulation was children's attention span/persistence temperament.

• 대한전기학회논문지
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• 제39권1호
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• pp.49-56
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• 1990

An induction motor position control system based on the sliding mode control is presented. In the sliding mode control, control function is discontinuous on the hyperplane, which causes harmful effects such a s current harmonics and acoustic noise in the motor drive application. In this study, a low pass filter is introduced between the sliding mode controller output and the motor controller input to reduce these effects. The filter, however, makes the torque response slggish and the system performance may become poor in cost of chattering reduction. To overcome these problems, the bandwidth of the filer is varied according to the error function. It is shown that the proposed sliding mode control with variable-bandwidth filter shows good performance, which is confirmed through experiments.

• The Journal of Korean Physical Therapy
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• 제31권2호
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• pp.94-102
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• 2019

Purpose: This study examined the effects of trunk control rehabilitation robot training (TCRRT) on the dynamic balance, lower extremity strength, gait ability and pain for bipolar hemiarthroplasty. Methods: Hemiarthroplasty (n=28) patients participated in this study. The subjects were randomized into two groups: trunk control rehabilitation robot training group and control group. Results: The TCRRT group showed significantly more improvement in the MFRT, MMT, 10MWT, TUG, and VAS compared to that before intervention (p<0.05). In addition, all tests were significantly greater in the experimental group than in the control group. Conclusion: These results suggest that TCRRT is feasible and effective for improving the dynamic balance, lower extremity strength, gait ability, and pain efficacy after bipolar hemiarthroplasty.

• Nutrition Research and Practice
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• 제4권6호
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• pp.470-476
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• 2010

The resistant dextrin NUTRIOSE$^{(R)}$, developed from starch, is expected to act as a prebiotic. The aim of this study was to determine the effects of NUTRIOSE$^{(R)}$ on cecal parameters, short-chain fatty acid (SCFA) concentrations, and fecal excretion in rats. In an initial experiment, twenty-four male Fischer F344 rats were randomly assigned to one of the following four treatments for 14 days: G0 (control diet), G2.5 (control diet+2.5% of dextrin), G5 (control diet + 5% of dextrin), and G10 (control diet + 10% of dextrin). After 14 days, total cecal weight, cecal content, and cecal wall weight were significantly increased in G5 and G10 compared to G0. At the same time, cecal pH was significantly lower in G10 compared to G0. Total SCFA concentration was significantly higher in G10 than in G5, G2.5, and G0, and significantly higher in G5 than in G0. Acetate, butyrate, and propionate concentrations were significantly increased in G5 and G10 compared to the controls. In a second trial based on a similar design, eighteen male Fischer F344 rats were treated with a control diet supplemented with 5% of dextrin or 5% of fructo-oligosaccharide. The results obtained with NUTRIOSE$^{(R)}$ were similar to those obtained with the fructo-oligosaccharide. In a third experiment, two groups of 5 Fischer F344 rats were orally treated with 100 and 1,000 mg/kg NUTRIOSE$^{(R)}$, respectively, and from 18% to 25% of the dextrin was excreted in the feces. The results of these three studies show that the consumption of NUTRIOSE$^{(R)}$, by its effects on total cecal weight, cecal content, cecal wall weight, pH, and SCFA production, could induce healthy benefits since these effects are reported to be prebiotic effects.