• Journal of Electrical Engineering and information Science
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• v.2 no.5
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• pp.27-32
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• 1997

This paper presents an H\ulcorner controller design method for linear time-invariant systems with delayed state and control. Using the second method of Lyapunov, the stability for delayed systems is discussed. For delayed systems, we derive a sufficient condition of the bounded real lemma(BRL) which is similar to GBRL for nondelayed systems. And the sufficent conditions for the existence of an H\ulcorner controller of any order are given in terms of three linear matrix inequalities(LMIs). Further, we briefly explain how to construct such controllers from the positive definite solutions of their LMIs and gie a simple example to illustrate the validity of the proposed design procedure.

• Proceedings of the KIEE Conference
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• 2004.05a
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• pp.77-79
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• 2004

Because robot hardware architecture generally is consisted of a few sensors and motors connected to the central processing unit, this type of structure is led to time consuming and unreliable system. For analysis, one of the fundamental difficulties in real-time system is how to be bounded the time behavior of the system. When a distributed control network controls the robot, with a central computing hub that sets the goals for the robot, processes the sensor information and provides coordination targets for the joints. If the distributed system supposed to be connected to a control network, the joints have their own control processors that act in groups to maintain global stability, while also operating individually to provide local motor control. We try to analyze the architecture of network-based humanoid robot's leg part and deal with its application using the CAN(Controller Area Network) protocol.

• International Journal of Control, Automation, and Systems
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• v.5 no.6
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• pp.630-642
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• 2007

In this paper, we propose a direct model reference adaptive fuzzy control (MRAFC) for MIMO nonlinear systems whose structure is represented by the Takagi-Sugeno fuzzy model. The adaptive law of the MRAFC estimates the approximation error of the fuzzy logic system so that it provides asymptotic tracking of the reference signal for the systems with uncertain or slowly time-varying parameters. The developed control law and adaptive law guarantee the boundedness of all signals in the closed-loop system. In addition, the plant state tracks the state of the reference model asymptotically with time for any bounded reference input signal. To verify the validity and effectiveness of the MRAFC scheme, the suggested analysis and design techniques are applied to the tracking control of robot manipulator and simulation studies are carried out. In the control design, the MRAFC is combined with feedforward PD control to make the actual joint trajectories of the robot manipulator with system uncertainties track the desired reference joint position trajectories asymptotically stably.

• The Journal of the Korea Contents Association
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• v.5 no.4
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• pp.245-253
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• 2005

The multimedia ad hoc wireless network is quite an attractive issue since it offers a flexible solution to enable delivery of multimedia services to mobile end users without fixed backbone networks. However, with the unique design challenges of ad hoc wireless networks, it is a non-trivial issue to provide bounded delay guarantee, with fair share of resources. In this paper, we proposed distributed implementation of the delay guaranteed fair queueing (DGFQ) scheme in multimedia ad hoc wireless networks. Through the the results of performance evaluation, we can conclude that DGFQ also performs well to control bounded delay in multimedia ad hoc wireless networks.

• Environmental Engineering Research
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• v.15 no.2
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• pp.117-121
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• 2010

The continual extraction and indiscriminante use of groundwater for residential sectors could cause a decrease in the groundwater level in Para$\tilde{n}$aque river and Las Para$\tilde{n}$aque City; and allows saltwater to penetrate into the aquifer due to the proximity of Manila Bay. This study models the present condition and extent of saltwater intrusion in the aquifer bounded by Para$\tilde{n}$aque river River and Manila Bay. The model is simulated using a 3D finite element modeling software (FEMWATER) that is capable of modeling the groundwater flow condition in the aquifer. Moreover, the model can also be used to predict the future condition of the aquifer for better groundwater management. This study aims to raise public awareness of the extent of the problem and the possible side effects incurred. The model will serve as a basis for further studies on remediation techniques and saltwater intrusion control in the coastal aquifer of Para$\tilde{n}$aque river City.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.6
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• pp.1177-1186
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• 2003

The multimedia ad hoc wireless network is quite an attractive issue since it offers a flexible solution to enable delivery of multimedia services to mobile end users without fixed backbone networks. However, with the unique design challenges of ad hoc wireless networks, it is a non-trivial issue to provide bounded delay guarantee, with fair share of resources. In this paper, we implemented the delay guaranteed fair queueing (DGFQ) scheme distributively. Through the results of performance evaluation, we can conclude that DGFQ also performs well to control bounded delay in multimedia ad hoc wireless networks.

• Economic and Environmental Geology
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• v.26 no.2
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• pp.217-226
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• 1993

Stream sediment samples were collected in the vicinity of the Sambo Pb-Zn-barite mine in order to investigate dispersion patterns and pollution levels of heavy metals, and to find out their mode of occurrences. Those samples were analyzed for Cd, Cu, Pb, Zn, Fe, and Mn by using partial extraction and sequential extraction methods. Stream sediments of this studied area has been contaminated severely by Pb, Zn, and Cd. Dispersion patterns of heavy metals in those sediments are different according to their pollution source and sampling distance from the mine. The stream sediment pH is generally neutral in control area, and is slightly acidic in the lower part of tailing dam. The main pollution source of stream sediments was confirmed as tailing and mine drainage. Their pollution level depends mainly on inflowed water and distance from the mine. The tolerance index ranges from -0.9 to 0.7. The mode of occurrances of heavy metals in polluted stream sediment are identified as Fe-Mn oxides, organic bounded and carbonate-bounded compound which show high potential of bioavailablity.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.13 no.1
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• pp.119-127
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• 1999

In this paper, a robust direct adaptive contrdler is presented in a linear time-invariant. Continuous systems with unmodeded dynamics and bounded disturbance using a rmdified control law and the adaptive law to Compensate for the drawback of ${\sigma}$-modification algorithm. The proposed algorithm is awlied to a plant with unrmdeled dynamics represented as a singular perturbation. Boundness of all signals in overall system is guaranteed with mathematical analysis. simulation results are presented the effectiveness foc the first-order plant even in the presence of unmodelled dynamics or bounded disturbance simulatneousIy.eousIy.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.10
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• pp.779-787
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• 2016

A nonlinear control law for the quad-rotor of a low-complexity, global approximation-free from system uncertainties and external disturbances are described in this paper. The control law guarantees convergence to a small bounded error using a prescribed performance function. The stability of the proposed nonlinear control system is also proven by the Lyapunov stability theorem. The advantage of this technique is that it has a simpler form than any other nonlinear compensators and is applicable to any nonlinear systems without precise knowledge of the systems. In this paper, the proposed approach is applied to attitude/altitude control of a quad-rotor. Numerical simulations are performed to investigate the proposed nonlinear attitude control law by applying it to an uncertain quadcopter system with external disturbances.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.33 no.5
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• pp.193-199
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• 1984

This paper presents a direct adaptive pole placement control scheme which is applicable to discretetime non-minimum phase systems. It is proved that by this scheme the poles can be placed at the desired locations and the overall state vector of the system is uniformly bounded if the reference input is sufficiently rich, and also proved that in case of insufficiently rich reference input the overall system can still be stabilized though the poles may not be placed exactly at the desired locations. The effectiveness of this scheme is verified by digital computer simulations.