• 한국인터넷방송통신학회논문지
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• 제12권2호
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• pp.9-17
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• 2012

인터넷은 패킷의 지연시간과 손실에 대한 보장을 제공하지 않기 때문에 일시적인 네트워크 혼잡은 H.264/SVC 스트리밍에 부정적인 영향을 줄 수 있다. 따라서 H.264/SVC 향상 계층을 제거하여 전송율을 제어함으로써 혼잡을 회피하는 기법이 필요하다. 본 논문에서는 비디오의 중요도에 따라 스트림을 분류한 후, 스트림의 비트율-왜곡 특성을 이용한 가중치 기반 혼잡 제어 알고리즘을 제안한다. 즉, 제한된 대역폭을 가진 네트워드 노드에서 가중치를 고려한 PSNR의 합을 최대화하기 위해, H.264/SVC 향상 계층의 수를 제어하는 WNS(Weighted Near-Sighted), WFS(Weighted Far-Sighted) 알고리즘을 제안한다. 그리고 시뮬레이션을 통해 가중치 기반 알고리즘의 효용성을 보이고 알고리즘의 특성을 분석한다.

• 한국정보통신학회논문지
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• 제13권5호
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• pp.913-921
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• 2009

본 연구에서는 강인한 성능을 가지는 해집단내에서 기준모델의 출력을 최적으로 추종하도록 유전 알고리즘을 사용하여 가중치 함수와 설계 파라메타 ${\gamma}$를 동시에 최적화함으로써, 강인한 성능에 관한 필요충분조건식을 만족함은 물론 설계사양에 따른 만족스러운 응답특성을 보이는 강인한 성능을 가지는 모델추종형 $H_{\infty}$ 제어기의 설계법을 제시하고 시뮬레이션을 통하여 그 유용성을 확인한다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1988년도 한국자동제어학술회의논문집(국내학술편); 한국전력공사연수원, 서울; 21-22 Oct. 1988
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• pp.476-481
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• 1988

In this paper a pH process of a weak acid with a strong base is modeled into a bilinear form, and a self-tuning pH control algorithm which is robust against initial values of solution and disturbances is presented. The control algorithm employs the recursive least square method for the parameter estimation and the generalised minimum variance criterion as the objective function. The computer simulation shows that the tracking of desired pH values is obtained in satisfactory manner regardless of the initial values chosen for the process.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.535-535
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• 2000

This paper presents an adaptive receding horizon H$_{\infty}$ controller for the linear parameter varying systems in the deterministic environment, which combines a parameter range estimator and a robust receding horizon H$_{\infty}$ controller using the parameter bounds. Using parameter set inclusion and terminal inequality condition, the closed-loop system stability is guaranteed. It is shown that the stabilizing adaptive receding horizon H$_{\infty}$ controller guarantees the H$_{\infty}$ norm bound.

• International Journal of Control, Automation, and Systems
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• 제2권1호
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• pp.23-38
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• 2004

We proposed the infinity control principle to evaluate the Biological function. The H infinity control was applied to the Sodium (Na) ion selective gating channel on the excitable cellular membrane of the neural system. The channel opening, closing and inactivation processes were expressed by movements of three gates and one inactivation blocking particle in the channel pore. The rate constants of the channel state transition were set to be voltage dependent. The temporal changes in amounts per unit membrane area of the channel states were expressed by means of eight differential equations. The biochemical mimetic used to complete the Na ion selective channel was regarded as noise. The control inputs for ejecting the blocking particle with plugging in the channel pore were set for the active transition from inactivated states to a closed or open state. By applying the H infinity control, we computed temporal changes in the channel states, observers, control inputs and the worst case noises. The present paper will be available for evaluating the noise filtering function of the biological signal transmission system.

• International Journal of Control, Automation, and Systems
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• 제4권5호
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• pp.653-659
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• 2006

The design of $H_2$-optimal control with regional pole assignment via state feedback in linear time-invariant systems is investigated. The aim is to find a state feedback controller such that the closed-loop system has the desired eigenvalues lying in some desired stable regions and attenuates the disturbance between the output vector and the disturbance vector. Based on a proposed result of parametric eigenstructure assignment via state feedback in linear systems, the considered $H_2$-optimal control problem is changed into a minimization problem with certain constraints, and a simple and effective algorithm is proposed for this considered problem. A numerical example and its simulation results show the simplicity and effectiveness of this proposed algorithm.

• Advances in aircraft and spacecraft science
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• 제6권5호
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• pp.371-389
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• 2019

The implementation of a robust $H_{\infty}$ Control, which is numerically efficient for uncertain nonlinear dynamics, on longitudinal and lateral autopilots is realised for a quarter scale Piper J3-Cub model accepted as an unmanned aerial vehicle (UAV) under the condition of sensor noise and disturbance effects. The stability and control coefficients of the UAV are evaluated through XFLR5 software, which utilises a vortex lattice method at a predefined flight condition. After that, the longitudinal trim point is computed, and the linearization process is performed at this trim point. The "${\mu}$-Synthesis"-based robust $H_{\infty}$ control algorithm for roll, pitch and yaw displacement autopilots are developed for both longitudinal and lateral linearised nonlinear dynamics. Controller performances, closed-loop frequency responses, nominal and perturbed system responses are obtained under the conditions of disturbance and sensor noise. The simulation results indicate that the proposed control scheme achieves robust performance and guarantees stability under exogenous disturbance and measurement noise effects and model uncertainty.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 하계종합학술대회 논문집(1)
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• pp.341-344
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• 2001

H.323 proposes to use Mobile IP and H.323 ad hoc conference signaling to provide Handoff function to an H.323 mobile terminal. But the H.323 ad hoc conference signaling has a drawback. It requires an H.323 terminal to do a complex conference signaling which takes a longer signaling time. In this paper, we propose an GK architecture that provides Handoff function effectively using 3$^{rd}$ P'||'||'||'||'||'&'||'||'||'||'||'R(Third party initiated Pause and Rerouting) signaling which are done through H.245 logical channel. The GK which is implementing 3$^{rd}$ P'||'||'||'||'||'&'||'||'||'||'||'R signaling only requires an H.323 endpoint to do the H.323 basic signaling in reestablishing media channel and gives the faster Handoff signaling. To do this, our GK has derived H.245 control channel using tunneling f3r all H.323 calls including the fast connect calls which enable terminals communicate each other if they doesn't have H.245 control channel .municate each other if they doesn't have H.245 control channel .

• 한국해양공학회지
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• 제10권3호
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• pp.153-161
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• 1996

This paper presents a design method of dynamic positioning control system for floating platform with rotatable and retractable thruster using $H_{\infty}$ control technique. The norm band of uncertainty is captured by multiplicative perturbation between nominal model and reduced order model. A controller robust to the uncertainty is designed applying $H_{\infty}$ synthesis. The control law satisfying robust stabillity and nominal performance condition is determined through the mixed sensitivity approach. The evaluation for the resultant controller obtained by $H_{\infty}$ synthesis is done through simulations of the closed loop system. The results of $H_{\infty}$ synthesis are compared to those of the traditional LQ synthesis method.

• 조명전기설비학회논문지
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• 제18권5호
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• pp.198-202
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• 2004

본 논문에서는 전력 시스템에서 가지고 있는 불확실성과 왜란에 강인함을 보장하면서 원하는 제어성능을 얻기 위해 강인 제어기 중의 하나인 H$_{\infty}$ 제어이론을 도입하여 강인제어기를 제안하였다. 디자인된 제어기의 성능은 폭넓은 비선형 시간영역 모의 실험으로 고찰하였다. 실험결과에서는 기존의 제어기보다 제안된 H$_{\infty}$ 제어기가 우수함을 보였다.