• Transactions on Control, Automation and Systems Engineering
• /
• 제1권2호
• /
• pp.87-93
• /
• 1999

This paper proposes a systematic designs methodology for the Takagi-Sugeno (TS) model based fuzzy control systems with guaranteed stability and pre-specified transient performance for the application to a nonlinear magnetic bearing system. More significantly, in the proposed methodology , the control design problems which considers both stability and desired transient performance are reduced to the standard LMI problems . Therefore, solving these LMI constraints directly (not trial and error) leads to a fuzzy state-feedback controller such that the resulting fuzzy control system meets above two objectives. Simulation and experimentation results show that the proposed LMI-based design methodology yields only the maximized stability boundary but also the desired transient responses.

• 제어로봇시스템학회논문지
• /
• 제5권2호
• /
• pp.145-150
• /
• 1999

A real-time control system, composed of the controlled processor and the controller computer(s), may have a variety of task types, some of which have tight timing-constraints in generating the correct control input. The maximum period of those task failures tolerable by the system is called the hard deadline, which depends on not only fault characteristics but also task characteristics. In the paper, we extend a method deriving the hard deadline in LTI system executing single task. An algorithm to combine the deadlines of all the elementary tasks in the same operation-mode is proposed to derive the hard deadline of the entire system. For the end, we modify the state equation for the task to capture the effects of task failures (delays in producing correct values) and inter-correlation. We also classify the type of executing the tasks according to operation modes associated with relative importance of correlated levels among tasks, into series, parallel, and cascade modes. Some examples are presented to demonstrate the effectiveness of the proposed methods.

• International Journal of CAD/CAM
• /
• 제6권1호
• /
• pp.89-97
• /
• 2006

This paper presents a novel approach for non-iterative surface smoothing with feature preservation on arbitrary meshes. Laplacian operator is performed in a global way over the mesh. The surface smoothing is formulated as a quadratic optimization problem, which is easily solved by a sparse linear system. The cost function to be optimized penalizes deviations from the global Laplacian operator while maintaining the overall shape of the original mesh. The features of the original mesh can be preserved by adding feature constraints and barycenter constraints in the system. Our approach is simple and fast, and does not cause surface shrinkage and distortion. Many experimental results are presented to show the applicability and flexibility of the approach.

• 한국경영과학회:학술대회논문집
• /
• 한국경영과학회 1989년도 추계학술발표회 발표논문초록집; 이화여자대학교, 서울; 23 Sep. 1989
• /
• pp.45-50
• /
• 1989

The above theorm states that much larger classes of differential games have an equilibrium. The most severe assumption is the second one. It requires that state dynamic equations be linear on his own control variables. But, the dynamic programming approach applied in the above is hardly implementable for the purpose of computation. It is very difficult to solve (SP$_{it}$) directly. Notice, however, the problem can be transformed into a Hamiltonian maximization problem which is easy to solve if initial conditions are given. In this way, it is possible to design a solution algorithm to problems with nonlinear constraints. The above two theorems probide a basis for such an algorithm.m.

• 한국경영과학회지
• /
• 제37권4호
• /
• pp.19-35
• /
• 2012

The Semantic Web technology, purporting to share, to reuse and to process by machines data stored in the Web environment, incessantly evolves to help human decision making; in particular, decision making based on data, or quantitative decision making. This trend drives researchers to fill the gap with strenuous efforts between the current state of the technology and the terminus of this evolution. The Semantic Web Constraint Language (SWCL) together with SWRL is one of these endeavors to achieve the goal. This paper focuses particularly on how to express the piecewise linear form in the context of SWCL. The importance of this ingredient can be fortified by the fact that any nonlinear expression can be approximated in the piecewise linear form. This paper will also provide the information of how it will work in the decision making process through an example of the Internet shopping mall problem.

• 경영과학
• /
• 제25권3호
• /
• pp.87-99
• /
• 2008

Besieged by needs for upgrading the current Internet, social pressures, and regulatory concerns, a network operator may be left with few options to Improve his services. Yet he can still consider a transition prioritizing network services. In this paper, we describe a transition from a non-priority system to a prioritized one, using non-preemptive M/G/1 model. After reviewing the constraints and theoretical results from past research, we describe steps making the transition Pareto-improving, which boils down to a multi-goal search for a Pareto-improving state. We use a genetic algorithm that captures actual transition costs along with incentive-compatible and Pareto-Improving constraints. Simulation results demonstrate that the initial post-transition solutions are typically Pareto-improving. for non Pareto-improving solutions, the heuristic quickly generates Pareto-improving and incentive-compatible solutions.

• Journal of Information Science Theory and Practice
• /
• 제1권4호
• /
• pp.67-75
• /
• 2013

This paper discusses awareness of institutional repositories and open access publishing among faculty members in Annamalai University, Tamil Nadu, India. The authors distributed 200 questionnaires among the faculty members in Annamalai University. Out of 200 questionnaires, 160 responses (80.00%) were received from faculty members. The respondents mentioned the motivating factors while using an institutional repository and indicated the benefits, constraints and strategies to develop open access in publications. It is evident from the table that more than 95% among the average of the faculty members confirm the benefits of open access in publications. 150 (93.75%) of faculty members have awareness, 6 (3.75%) have no idea and 4 (2.50%) state no opinion about awareness of institutional repository and open access publishing.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
• /
• pp.515-515
• /
• 2000

The performance of dynamic path following of a wheeled mobile robot with nonholonomic constraints has some drawbacks such as the influence of the initial state. The drawbacks can be overcome by the temporary path generator and modified output. But with the previous input-output linearization method using them, it is difficult to tune the gains, and if there are some modeling errors, the low gain can make the system unstable. And if a high gain is used to overcome the model uncertainties, the control inputs are apt to be large so the system can be unstable. In this paper. an H$_{\infty}$ controller is designed to guarantee robustness to model parameter uncertainties and to consider the magnitude of control inputs. And the solution to Hamilton Jacobi (HJ) inequality, which is essential to H$_{\infty}$ control design, is obtained by nonlinear matrix inequality (NLMI).

• 한국항해항만학회:학술대회논문집
• /
• 한국항해항만학회 2004년도 춘계학술대회 논문집
• /
• pp.135-140
• /
• 2004

본 논문에서는 비 홀로노믹적인 구속조건을 갖는 수중 이동체의 위치 및 자세제어에 관한 제어기법에 대해서 논의한다. 비 홀로노믹 시스템은 적분 불가능한 구속조건으로부터 도출되어지는 시스템으로 연속시간영역의 피트백제어로는 평형점에서의 안정화제어가 불가능한 특성을 가지고 있다. 본 연구에서는 속도의 비 홀로노믹 구속조건을 가지는 수중 이동체에 대하여 체인트폼으로 변환하고 변환된 시스템에 대해 백스테핑 제어기법을 적용하여 자세제어를 행하고 수치시뮬레이션을 통하여 제어기법의 유용성을 평가하였다.

• 대한전기학회논문지:전력기술부문A
• /
• 제55권12호
• /
• pp.549-554
• /
• 2006

Available transfer capability(ATC) is an important indicator of the usable amount of transmission capacity accessible by several parties for commercial trading in power transaction activities. This paper deals with an application of optimization technique for available transfer capability(ATC) calculation and analyzes the results of ATC by considering several constraints. Especially several optimization techniques are used to solve the ATC problem with state-steady security constraints. The results are compared with that of repeat power flow(RPF), sequential quadratic programming(SQP) and linear programming(LP). The proposed method is applied to 10 machines 39 buses model systems to show its effectiveness.