• 전기학회논문지
• /
• 제61권3호
• /
• pp.459-465
• /
• 2012

In this paper, we present a non-fragile guaranteed cost control design method for uncertain nonlinear systems with time varying delays in state and control input, even though the controller gain is perturbed. The uncertain nonlinear term in the systems is norm bounded and the linear matrix inequality(LMI) optimization method is employed as a stability analysis of the systems. We design a robust controller and show the asymptotical stability of uncertain time-varying systems based on Lyapunov method. Also, we guarantee a specific level of performance of the systems. The simulations are carried out to demonstrate the effectiveness of the proposed method.

• Advances in concrete construction
• /
• 제9권4호
• /
• pp.407-412
• /
• 2020

Due to the influence of nonlinearity and time-variation, it is difficult to establish an accurate model of concrete frame structures that adopt active controllers. Fuzzy theory is a relatively appropriate method but susceptible to human subjective experience to decrease the performance. To guarantee the stability of multi-time delays complex system with multi-interconnections, a delay-dependent criterion of evolved design is proposed in this paper. Based on this criterion, the sector nonlinearity which converts the nonlinear model to multiple rule base of the linear model and a new sufficient condition to guarantee the asymptotic stability via Lyapunov function is implemented in terms of linear matrix inequalities (LMI). A numerical simulation for a three-layer reinforced concrete frame structure subjected to earthquakes is demonstrated that the proposed criterion is feasible for practical applications.

• Journal of applied mathematics & informatics
• /
• 제29권1_2호
• /
• pp.279-292
• /
• 2011

In this paper, we consider anti-periodic solutions of the following BAM neural networks with multiple delays on time scales: $$\{{x^\Delta_i(t)=-a_i(t)e_i(x_i(t))+{\sum\limits^m_{j=1}}c_{ji}(t)f_j(y_j(t-{\tau}_{ji}))+I_i(t),\atop y^\Delta_j(t)=-b_j(t)h_j(y_j(t))+{\sum\limits^n_{i=1}}d_{ij}(t)g_i(x_i(t-{\delta}_{ij}))+J_j(t),}\$$ where i = 1, 2, ..., n,j = 1, 2, ..., m. Using some analysis skills and Lyapunov method, some sufficient conditions on the existence and exponential stability of the anti-periodic solution to the above system are established.

• Journal of Communications and Networks
• /
• 제9권1호
• /
• pp.34-42
• /
• 2007

Orthogonal frequency division multiplexing (OFDM) combined with time division multiplexing (TDM), in this paper called OFDM/TDM, can overcome the high peak-to-average-power ratio (PAPR) problem of the conventional OFDM and improve the robustness against long time delays. In this paper, the bit error rate (BER) performance of OFDM/FDM in a frequency-selective Rayleigh fading. channel is evaluated by computer simulation. It is shown that the use of frequency-domain equalization based on minimum mean square error criterion (MMSE-FDE) can significantly improve the BER performance, compared to the conventional OFDM, by exploiting the channel frequency-selectivity while reducing the PAPR or improving the robustness against long time delays. It is also shown that the performance of OFDM/FDM designed to reduce the PAPR can bridge the conventional OFDM and single-carrier (SC) transmission by changing the design parameter.

• Journal of Electrical Engineering and Technology
• /
• 제7권3호
• /
• pp.366-375
• /
• 2012

This paper describes a design and temporal analysis of a hardware-in-the-loop (HIL) simulation environment for testing a motor control unit (MCU). The design concepts and main characteristics including unavoidable time delays of each component module are described. From temporal analysis results according to the module integration method, an appropriate solution is proposed to fix and minimize time delays. In order to verify the effectiveness of the proposed solution, the HIL test results are compared with the results of experiments and an offline simulation.

• 한국통신학회논문지
• /
• 제16권6호
• /
• pp.533-544
• /
• 1991

In this paper, the performance of bridges used to interconnect LAN to FD야 backbone networks as well as the performance of MAC protocols for FD야 backbone networks were thoroughly analyzed, The exhaustive service discipline and three ource models were applied to analyze the mean waiting time of the system. the performance is evaluated in terms of the service rate of bridge, total load of backbone. medium length of back bone, value of T and station latency. The result of analysis show that in general , processing delay of the system is mainly determined by bridge delays. But when processing time of bridge mereases, processing delays of the system are primarily determined by MAC protocols. Therefore, speed-up of processing time of bridge is necessary to efficiently use the high speed backbone networks.

• 전기학회논문지
• /
• 제60권11호
• /
• pp.2119-2130
• /
• 2011

This paper proposes new delay-dependent robust stability criteria for neural networks with time-varying delays. By construction of a suitable Lyapunov-Krasovskii's (L-K) functional and use of Finsler's lemma, new stability criteria for the networks are established in terms of linear matrix inequalities (LMIs) which can be easily solved by various effective optimization algorithms. Two numerical examples are given to illustrate the effectiveness of the proposed methods.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2003년도 하계학술대회 논문집 D
• /
• pp.2242-2244
• /
• 2003

This paper considers a networked control system (NCS) that consists of an inverted cart pendulum, a digital controller, and a controller area network (CAN) in which the actuator and sensors of the pendulum are connected to form a closed-loop system. The worst-case message response time (WCMRT) in the CAN is analyzed and the analysis results are applied to the target control system. For the case where the control system cannot satisfy the WCMRT condition and therefore time delays are inevitable, the Luck and Ray method is used to compensate the network-induced time delays. Simulations are carried out to show the feasibility of the proposed scheme.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2001년도 ICCAS
• /
• pp.34.3-34
• /
• 2001

The design method of H$\infty$ filter for discrete-time uncertain linear systems with multiple state delays is investigated. The uncertain parameters are assumed to be unknown but belonging to known convex compact set of polytope type less conservative than norm bounded parameter uncertainty. The modified H$\infty$ performance measure is introduced to consider the initial states values which affect the performance of filter. The objective is to design a stable H$\infty$ filter guaranteeing asymptotic stability of filtering error dynamics and minimizing H$\infty$ norm bound. The sufficient condition for the existence of filter and the filter design method are established by LMI (linear matrix inequality) approach.

• 한국건설관리학회논문집
• /
• 제8권3호
• /
• pp.125-133
• /
• 2007

건설공사 계약에서 공기연장 시에는 계약당사자의 귀책에 따라 지체상금의 부과 내지는 연장비용을 지급토록 규정하고 있으나, 그 이행에 있어 당사자의 정량적 귀책구분 등 분석결과에 의해 전형적으로 이행되는 경우는 거의 없다고 할 수 있다. 결국 이는 수행참여자의 계약적 의무이행에 대한 책임회피이며, 향후 잠재된 공기연장클레임 등 더 많은 시간과 비용을 지불해야 하는 분쟁으로 비화될 것은 자명하다 할 것이다. 그 원인으로는 현행의 CPM 네트워크공정표에 의한 공정관리 방법 이 수동적이고 사후적 인 관리로서 공기 연장이 발생한 후, 그 사유 및 기간의 책임분석을 통한 관리로 그 한계성으로 인하여 연장예방 및 클레임해결이 불가능한 것이다. 따라서 본 연구에서는 현행 계약자들의 공정관리 수준을 고려하고, 공기연장의 핵심이라 할 수 있는 연장사유에 대한 사전관리를 통한 프로세스 접근방식(Process Approach)의 공기연장사유 관리모델을 제시하여 프로젝트 수행 당사자의 책임의식 고취와 책임관리, 사전관리, 증거관리를 능동적으로 수행 가능할 수 있게 하여, 공기 연장예방 및 당사자의 원만한 클레임해결을 위한 관리기준 모델을 제시하는 것이다.