• Proceedings of the Korea Information Processing Society Conference
• /
• 2003.05a
• /
• pp.189-192
• /
• 2003

분산 시스템의 관리를 위해서 시스템 내의 각 컴포넌트에서 발생되는 많은 이벤트 중에 의미 있는 이벤트를 효과적으로 찾아내는 이벤트 파싱 엔진이 필요하다. 본 논문에서는 유연성 있는 이벤트 파싱 엔진을 제안한다. 특히 이벤트 파싱 엔진의 내부 구현을 위해서 기존의 룰 기반 접근방법을 변형한 새로운 접근방법을 제시한다. 본 엔진에서는 룰의 조건과 액션을 스크립트 객체화한 스크립트 객체 기반 접근방법과 룰에 해당하는 이벤트들을 찾아낼 때 보다 효과적이 검색을 지원하는 이벤트 토큰 기반 방식을 사용한다.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2015.04a
• /
• pp.515-517
• /
• 2015

본 연구는 블록 형태의 프로그래밍 툴인 앱 인벤터를 이용해 학생들의 학업에 대한 정보와 궁금증을 해결해 줄 수 있는 인터넷 강의평가 앱 개발을 연구하였다. 앱을 개발하는 과정에서 웹 데이터베이스와 구글 퓨전 테이블을 이용하여 로그인 기능과 사용자들에게 공유하여 볼 수 있는 게시판 기능을 추가하였다. 이 기능을 통하여 사용자간에 정보를 공유하여 인터넷강의 선정에 정보제공 방법을 연구하였다.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2021.10a
• /
• pp.239-239
• /
• 2021

• Proceedings of the KIEE Conference
• /
• 2008.04a
• /
• pp.51-52
• /
• 2008

In this paper, we propose two control schemes. The first control scheme is an adaptive passivity-based excitation control which regulates the terminal voltage to its reference. This controller is obtained through two steps: firstly, a simple direct adaptive passivation controller is designed for the power system with parametric uncertainties; then a linear PI controller is applied to converge the terminal voltage to its reference. The second control scheme is a linear governor control which consists of the frequency and the mechanical power. It is shown that the internal dynamics are locally stable with controllable damping. In the end, the boundness of all electrical variables, the frequency, the mechanical power, and the convergence of the terminal voltage to its reference can be achieved by these control schemes.

• Journal of Institute of Control, Robotics and Systems
• /
• v.8 no.12
• /
• pp.991-997
• /
• 2002

The concept of feasible & invariant region plays an important role to derive closed loop stability and achie adequate performance of constrained receding horizon predictive control. In this paper, we define a complex polyhedral feasible & invariant set for all stabilizable input-constrained linear systems by using a complex transform and propose a one-norm based receding horizon control scheme using these invariant sets. In order to get a larger stabilizable set, a convex hull of invariant sets which are defined for different state feedback gains is used as a target invariant set of the constrained receding horizon control. The proposed constrained receding horizon control scheme is formulated so that it can be solved via linear programming.

• Proceedings of the KIEE Conference
• /
• 2004.11c
• /
• pp.669-671
• /
• 2004

This paper presents a MIMO nonlinear controller for the power system consisting of a turbine and a synchronous generator connected to an infinite bus. The controller proposed is based on feedback input-output linearization; its main goal is to regulate the terminal voltage and frequency, and is to improve the transient stability under large disturbances and unexpected faults. It is guaranteed that the voltage converges to its reference value exponentially, and that the frequency and the mechanical/electrical power are bounded. The design procedure is tested on a single machine infinite bus power system through simulations, and is seen to be effective.

• Proceedings of the KIEE Conference
• /
• 2004.11c
• /
• pp.672-674
• /
• 2004

Many nonlinear controllers for the power system are based on nonlinear models involving the power angle as an element of the state, and therefore the reference value for the power angle is needed. As this reference value is not generally available, it is difficult to apply such nonlinear control methods in practice. To deal with this problem, we present an input-output feedback linearizing control scheme by selecting the output as a combination of the squared voltage and the relative frequency. It is shown that the internal dynamics are locally stable with controllable damping, and that the frequency remains bounded for all time. Simulations illustrate the effectiveness of the proposed method.

• 한국약용작물학회:학술대회논문집
• /
• 2011.04a
• /
• pp.90-91
• /
• 2011

• Proceedings of the KIEE Conference
• /
• 1991.07a
• /
• pp.583-586
• /
• 1991

This paper presents a comprehensive study on the stability of several control schemes for the induction motor driven by current source inverters. A stator voltage-controlled current source inverter drive system without a speed sensor is investigated in order to find appropriate control schemes, which are primarily based on direct or, alternatively, indirect frequency control scheme. The overall control systems with either voltage control loop or current and voltage control loops provided in addition to each frequency control scheme are analyzed by utilizing the root locus method and simulated by computer to illustrate the validity of this analysis.

• Proceedings of the KIEE Conference
• /
• 2003.11b
• /
• pp.47-50
• /
• 2003

For large-scale systems which are composed of interconnections of many lower-dimensional subsystems, decentralized control is preferable since it can alleviate the computational burden, avoid communication between different subsystems, and make the control more feasible and simpler. A power system is such a large-scale system where generators are interconnected through transmission lines. Decentralized control is therefore considered for power systems. In this paper, a robust decentralized excitation control scheme for interactions is proposed to enhance the transient stability of multimachine power systems. First we employ a DFL(Direct Feedback Linearization) compensator to rancel most of the nonlinearities; however, the resulting model still contains nonlinear interconnections. Therefore, we design a robust controller in order to deal with Interconnection terms. In this procedure, an upper bound of interconnection terms is estimated by an estimator. The resulting adaptive scheme guarantees the uniform ultimate boundedness of the closed-loop dynamic systems in the presence of the uncertainties.