• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.8 no.1
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• pp.41-54
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• 2004

Sufficient conditions for the controllability of neutral functional integrodifferential systems with infinite delay in Banach space are established by means of the Schaefer fixed point theorem.

• Journal of applied mathematics & informatics
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• v.7 no.3
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• pp.969-982
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• 2000

The approximate controllability for the nonlinear control system with nonlinear monotone hemicontinuous and coercive operator is studied. The existence, uniqueness and a variation of solutions of the system are also given.

• Journal of applied mathematics & informatics
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• v.23 no.1_2
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• pp.445-453
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• 2007

This paper deals with the approximate controllability for the nonlinear functional differential equations with time delay and studies a variation of constant formula for solutions of the given equations.

• Journal of the Microelectronics and Packaging Society
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• v.27 no.1
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• pp.31-35
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• 2020

This study demonstrates metal-oxide based memtransistor device and the gate tunable memristive characteristic using atomic layer deposition (ALD) and ZnO n-type oxide semiconductor. We fabricated a memtransistor device having channel width 70 ㎛, channel length 5 ㎛, back gate, using 40 nm thick ZnO thin film, and measured gate-tunable memristive characteristics at each gate voltage (50V, 30V, 10V, 0V, -10V, -30V, -50V) under humidity of 40%, 50%, 60%, and 70% respectively, in order to investigate the relation between a memristive characteristic and hydrogen doping effect on the ZnO memtransistor device. The electron mobility and gate controllability of memtransistor device decreased with an increase of humidity due to increased electron carrier concentration by hydrogen doping effect. The gate-tunable memristive characteristic was observed under humidity of 60% 70%. Resistive switching ratio increased with an increase of humidity while it loses gate controllability. Consequently, we could obtain both gate controllability and the large resistive switching ratio under humidity of 60%.

• Korean Journal of Applied Biomechanics
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• v.18 no.2
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• pp.65-74
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• 2008

The purpose of this study was to investigate the effect on postural control and shooting record by archers of the balance exercise program for 12-weeks based on sprinter/skater pattern. the subject were 12 female archers(the control group 6, the experimental group 6) and the motion was measured using active balance system. the results were as follows. 1. Static postural controllability of archers was improved to reduce the whole path length and the sway of the COBx, COBy after the balance exercise program for 12-weeks based on sprinter/skater pattern. 2. Dynamic postural controllability of archers was improved to reduce the whole path length after the balance exercise program for 12-weeks based on sprinter/skater pattern. 3. Archers' postural controllability was improved when shooting after 12-week balance exercise program based on sprinter/skater pattern. but not effect shooting record.

• Journal of Distribution Science
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• v.7 no.2
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• pp.45-61
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• 2009

The aims of this paper is to examine the key factor of customer satisfaction in the medical service. Especially service waiting is a significant component of the customer's overall satisfaction with the service process. For this purpose, this study proposed 6 hypotheses as follow : H1 : Waiting cost, affect on perceived service waiting, will be different between patient customer group and health care group. H2 : Controllability of the cause, affect on perceived service waiting, will be different between patient customer group and health care group. H3 : Controllability of the cause affect on perceived service waiting, will be different between patient customer group and health care group. H4 : Waiting environment, affect on perceived service waiting, will be different between patient customer group and health care group. H5 : Transaction importance, affect on perceived service waiting, will be different between patient customer group and health care group. H1 : Waiting cost, Controllability of the cause, Controllability of the cause, Waiting environment, Transaction importance, customer satisfaction will affect on service waiting significantly This study find that 1) Waiting cost and Transaction importance are significant variables to influence customer satisfaction between patient group and health care group. 2) customer satisfaction is very important variables to minimize perceived service waiting.

• 전자공학회논문지 IE
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• v.44 no.3
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• pp.51-55
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• 2007

In this paper, we consider the controllability and observability for the time-varying linear system using the input-state(I/O), input-output(I/O) transformation and get the time-invarying linear system. The transformed system represent the system with the multiple integral. We verify the proposal algorithm via the example and examine.

• Journal of the Korean Institute of Intelligent Systems
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• v.13 no.4
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• pp.499-503
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• 2003

This paper we study the exact controllability for the nonlinear fuzzy control system in $E_N^n$by using the concept of fuzzy number of dimension n whose values are normal, convex, upper semicontinuous and compactly supported surface in $E_N^n$

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.4 no.1
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• pp.1-6
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• 2004

This paper deals with a balanced model reduction for T-S(Takagi-Sugeno) fuzzy systems with time varying state delay. We define a generalized controllability gramian and a generalized observability gramian for a stable T-S fuzzy delayed systems. We obtain a balanced state space realization using the generalized controllability and observability gramian and obtain a reduced model by truncating states from the balanced state space realization. We also present an upper bound of the approximation error. The generalized controllability gramian and observability gramian can be computed from solutions of linear matrix inequalities. We demonstrate the efficacy of the suggested method by illustrating a numerical example.

• International Journal of Aeronautical and Space Sciences
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• v.17 no.1
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• pp.54-63
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• 2016

A novel attitude tacking control method using Time Delay Control (TDC) scheme is developed to provide robust controllability of a rigid hexacopter in case of single or multiple rotor faults. When the TDC scheme is developed, the rotor faults such as the abrupt and/or incipient rotor faults are considered as model uncertainties. The kinematics, modeling of rigid dynamics of hexacopter, and design of stability and controllability augmentation system (SCAS) are addressed rigorously in this paper. In order to compare the developed control scheme to a conventional control method, a nonlinear numerical simulation has been performed and the attitude tracking performance has been compared between the two methods considering the single and multiple rotor faults cases. The developed control scheme shows superior stability and robust controllability of a hexacopter that is subjected to one or multiple rotor faults and external disturbance, i.e., wind shear, gust, and turbulence.