• Smart Structures and Systems
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• 제19권4호
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• pp.351-360
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• 2017

Protection of structures against natural hazards such as earthquakes has always been a major concern. Semi-active control combines the reliability of passive control and versatility and adaptability of active control. So it has recently become a preferred control method. This paper proposes an algorithm based on Uniform Deformation Theory to mitigate vulnerable buildings using magneto-rheological (MR) damper. Due to the successful performance of fuzzy logic in control of systems and its simplicity and intrinsically robustness, it is used here to regulate MR dampers. The particle swarm optimization (PSO) algorithm is also used as an adaptive method to develop a fuzzy control algorithm that is able to create uniform inter-story drifts. Results show that the proposed algorithm exhibited a desirable performance in reducing both linear and nonlinear seismic responses of structures. Performance of the presented method is indicated in compare with passive-on and passive-off control algorithms.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제49권3호
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• pp.165-168
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• 2000

Improvement on the switching characteristic of IGBT by means of the uniform and local lifetime control is studied numerically using two-dimensional simulator, MEDICI. In the case of uniform lifetime control, the on-state and switching characteristics are simulated as a function of lifetime, and compared with the experimental results reported, which allows a relationship between dose of electron irradiation and controlled lifetime. In the case of local lifetime control, simulations are carried out by varying the position, width, and lifetime of the locally controlled region, and the results are compared with the characteristics for the case of the uniform lifetime control. The turn-off time of the device with an optimized locally controlled region is found to decrease from about $4.5\mus$ to 0.11$mutextrm{s}$ while the forward voltage drop increases from 1.37V to 2.61V in comparison with that for the uniform lifetime control.

• Journal of Biosystems Engineering
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• 제21권4호
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• pp.406-413
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• 1996

A control system for a self-propelled boom sprayer to spray at uniform application rate was developed and evaluated. The ground speed of the sprayer was converted into voltage. The voltage was used as an input signal. Output signal was current of a servo motor, that controlled application pressure of the sprayer with a feedback control system. Spraying was executed at the pressure of 20~55 psi and the speed of 0.640~0.696 km/hr and 1.040-1.131 km/hr. Although the pressure and the speed of sprayer were changed continuously, application rate was tried to keep a nearly constant amount of 666.67 L/ha. This result showed that the developed control system for uniform application rate was adoptable for the self-propelled sprayer.

• 한국의류산업학회지
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• 제18권5호
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• pp.668-676
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• 2016

The purposes of this study were to investigate the satisfaction of working uniform in Nuclear Power Plant and to suggest the improvement of dissatisfaction. 150 workers in control area of Nuclear Power Plant were participated in survey and 30 questionnaires were asked and subjective description was allowed. 65%/35% Poly/Rayon coverall type working uniform was investigated for this survey which had been wearing usually and basically in control area in Nuclear Power Plant. According to the results, respondents were most highly dissatisfied with the wearing convenience aspect of current coverall among any other aspects, like textile and management. In wearing convenience aspects, wrist and ankle opening band system, the design, number and placement of pocket, waist belt design, the width of sleeve and pants, and ADR opening system were dissatisfied and requested for improvement. In textiles aspects, weight, protection from radiation materials, prevention from static electricity, moisture absorption, ventilation and flexibility/elasticity were dissatisfied and requested for improvement. In management aspect, washing uniform and size variation were dissatisfied and requested for improvement. Therefore, for more comfortable human interfaced working uniform, wearing convenience system as well as textile and management system must be compensated and should be newly developed for improving worker comfort, mobility, and productivity.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1998년도 The Third Asian Fuzzy Systems Symposium
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• pp.413-416
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• 1998

In this paper we first show that uniform PR systems and half independent PR systems have same dynamics, and then an important property of this two kinds of systems is derived. The most important property of uniform PR systems is that they have the ability of classifying m-dimensional problabilistic vector into in classes. The significance of studying the dynamics of uniform PR systems are tried from the beginning with a uniform PR system.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.38.1-38
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• 2001

In this paper, the vibration suppression problem of an axially moving power transmission belt is investigated. The equations of motion of the moving belt is first derived by using Hamilton´s principle for systems with changing mass. The total mechanical energy of the belt system is considered as a Lyapunov function candidate. Using the Lyapunov second method, a nonlinear boundary control law that guarantees the uniform asymptotic stability is derived. The control performance with the proposed control law is simulated. It is shown that a boundary control can still achieve the uniform stabilization for belt systems.

• Coupled systems mechanics
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• 제7권3호
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• pp.269-280
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• 2018

Post-earthquake damages investigation in past and recent earthquakes has illustrated that the ground motion spatial variation plays an important role in the structural response of long span bridges. For the structural control of seismic-induced vibrations of cable-stayed bridges, it is extremely important to include the effects of the ground motion spatial variation in the analysis for design of an effective control system. The feasibility and efficiency of different vibration control strategies for the cable-stayed bridge under multiple support excitations have been examined to enhance a structure's ability to withstand earthquake excitations. Comparison of the response due to non-uniform input ground motion with that due to uniform input demonstrates the importance of accounting for spatial variability of excitations. The performance of the optimized designed control systems for uniform input excitations gets worse dramatically over almost all of the evaluation criteria under multiple-support excitations.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 Proceedings of the Korea Automatic Control Conference, 11th (KACC); Pohang, Korea; 24-26 Oct. 1996
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• pp.119-122
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• 1996

The recently proposed control method using a Lyapunov-like function can give global asymptotic stability to a system with mismatched uncertainties if the uncertainties are bounded by a known function and the uncontrolled system is locally and asymptotically stable. In this paper, we modify the method so that it can be applied to a system not satisfying the latter condition without deteriorating qualitative performance. The assured stability in this case is uniform ultimate boundedness which is as useful as global asymptotic stability in the sense that it is global and the bound can be taken arbitrarily small. By the proposed control law we can deal with both matched and mismatched uncertain systems. The above facts conclude that Lyapunov-like control method is superior to any other Lyapunov direct methods in its applicability to uncertain systems.

• 한국가정과교육학회지
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• 제6권2호
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• pp.85-108
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• 1994

This study intends to provide sources which enable students to satisfy uniform design as I surveyed preferable uniform design and degree of satisfaction of uniform design to students. The subjects were gathered into 91 middle-high schools and surveys were done among 400 school girls. The results are as follows; 1)The survey of uniform which students wear. For jacket, tailored collar which is single breasted is most common and for blouse, puff sleeve, soutein collar, shirt collar is common. For skirt, lastly, they usually wear side pleats skirt. 2) Thoughts of uniform students preferred uniform to casual. The merit of wearing uniform can represent themselves as the ‘students’on the other hand, the demerit is shown that uniform is inconvenient enough to move. 3)Preference of uniform design. Students prefer tailored jacket, shirt blouse, flare skirt. Basing on these results above, I’d like to suggest something about uniform. The demerit of wearing uniform lies in inconvenience. It would weaken the degree of satisfaction of uniform and have a negative influence on students in physical and mental side. So we have to find out the concrete problems, at the same time, develop measurable study which fit for body. Adolescence is period of developing and establishing self. So they really need rather creative educational atmosphere than stereo typed-control. Reflecting this opinion, Clothing habits can play an important role and in future it is desirable to have students wear not uniform but casual.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 추계학술대회논문집
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• pp.944-949
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• 2003

This paper addresses the control of free and dynamic response of composite rotating pretwisted blade modeled as non-uniform thin-walled beam fixed at the certain presetting and pretwisted angle and incorporating piezoelectric induced damping capabilities. A distributed piezoelectric actuator pair is used to suppress the vibrations caused by external disturbances. The blade model incorporates non-uniform features such as transverse shear, secondary warping and includes the centrifugal and Coriolis force field. A velocity feedback control law relating the piezoelectiriccally induced transversal bending moment at the beam tip with the appropriately selected kinematical response quantity is used and the beneficial effects upon the closed loop eigenvibration and dynamic characteristics of the blade are highlighted.