• Title/Summary/Keyword: Constraints

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A Method using Parametric Approach for Constrained Optimization and its Application to a System of Structural Optimization Problems (제약을 갖는 최적화문제에 대한 파라메트릭 접근법과 구조문제의 최적화에 대한 응용)

  • Yang, Y.J.;Kim, W.S.
    • Journal of the Korean Operations Research and Management Science Society
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    • v.15 no.1
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    • pp.73-82
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    • 1990
  • This paper describes two algorithms to Nonlinear programming problems with equality constraints and with equality and inequality constraints. The first method treats nonlinear programming problems with equality constraints. Utilizing the nonlinear programming problems with equality constraints. Utilizing the nonlinear parametric programming technique, the method solves the problem by imbedding it into a suitable one-parameter family of problems. The second method is to solve a nonlinear programming problem with equality and inequality constraints, by minimizing a square sum of nonlinear functions which is derived from the Kuhn-Tucker condition.

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The Scheme for Distributing the Query Constraints using the Sensor Networks (센서 네트워크를 이용한 질의 배분 기법)

  • Kim, Dong-Hyun
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2010.10a
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    • pp.691-694
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    • 2010
  • Since the data collected at a sensor node is the stream data, for processing efficiently user queries, the query index should be constructed at each node. To construct the minimized query index at the node, it is required to reduce the number of query constraints inserted into the query index. In this paper, we propose the scheme of the query constraints distribution using the multi-dimensional data index in order to diminish the number of the inserted query constraints.

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Energy constraint control in numerical simulation of constrained dynamic system

  • 윤석준
    • 제어로봇시스템학회:학술대회논문집
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    • 1991.10a
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    • pp.376-382
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    • 1991
  • In the analysis of constrained holonomic systems, the Lagange multiplier method yields a system of second-order ordinary differential equations of motion and algebraic constraint equations. Conventional holonomic or nonholonomic constraints are defined as geometric constraints in this paper. Previous works concentrate on the geometric constraints. However, if the total energy of a dynamic system can be computed from the initial energy plus the time integral of the energy input rate due to external or internal forces, then the total energy can be artificially treated as a constraint. The violation of the total energy constraint due to numerical errors can be used as information to control these errors. It is a necessary condition for accurate simulation that both geometric and energy constraints be satisfied. When geometric constraint control is combined with energy constraint control, numerical simulation of a constrained dynamic system becomes more accurate. A new convenient and effective method to implement energy constraint control in numerical simulation is developed based on the geometric interpretation of the relation between constraints in the phase space. Several combinations of energy constraint control with either Baumgarte's Constraint Violation Stabilization Method (CVSM) are also addressed.

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Optimal Period and Priority Assignment Using Task & Message-Based Scheduling in Distributed Control Systems (분산 제어 시스템에서의 태스크와 메시지 기반 스케줄링을 이용한 최적 주기와 우선순위 할당)

  • 김형육;이철민;박홍성
    • Journal of Institute of Control, Robotics and Systems
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    • v.8 no.6
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    • pp.506-513
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    • 2002
  • Distributed control systems(DCS) using fieldbus such as CAN have been applied to process systems but it is very difficult to design the DCS while guaranteeing the given end-to-end constraints such as precedence constraints, time constraints, and periods and priorities of tasks and messages. This paper presents a scheduling method to guarantee the given end-to-end constraints. The presented scheduling method is the integrated one considering both tasks executed in each node and messages transmitted via the network and is designed to be applied to a general DCS that has multiple loops with several types of constraints, where each loop consists of sensor nodes with multiple sensors, actuator nodes with multiple actuators and controller nodes with multiple tasks. An assignment method of the optimal period of each loop and a heuristic assignment rule of each message's priority are proposed and the integrated scheduling method is developed based on them.

The Ramp-Rate Constraint Effects on the Generators' Equilibrium Strategy in Electricity Markets

  • Joung, Man-Ho;Kim, Jin-Ho
    • Journal of Electrical Engineering and Technology
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    • v.3 no.4
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    • pp.509-513
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    • 2008
  • In this paper, we investigate how generators' ramp-rate constraints may influence their equilibrium strategy formulation. In the market model proposed in this study, the generators' ramp-rate constraints are explicitly represented. In order to fully characterize the inter-temporal nature of the ramp-rate constraints, a dynamic game model is presented. The subgame perfect Nash equilibrium is adopted as the solution of the game and the backward induction procedure for the solution of the game is designed in this paper. The inter-temporal nature of the ramp-rate constraints results in the Markov property of the game, and we have found that the Markov property of the game significantly simplifies the subgame perfect Nash equilibrium characterization. Finally, a simple electricity market numerical illustration is presented for the successful application of the approach proposed.

Development of Multi-body Dynamics Analysis Program with Constraints using CFEM (CFEM을 이용한 구속조건이 있는 다물체 운동해석 프로그램 개발)

  • Park, Sun-Ho;Lee, Seung-Soo
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.40 no.2
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    • pp.101-107
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    • 2012
  • In this study, Constraint Force Equation Methodology (CFEM) is used to develop a multi-body dynamic analysis program with constraints. Seven constraint models are implemented to analyze constraint motions of multiple bodies. The augmented equations with the constraints are solved with the 4th order Runge-Kutta method for higher degree of accuracy. The analysis code is verified by comparing the analysis results of the motion of bodies with various constraints to published results.

A Representation of Engineering Change Objects and Their Integrity Constraints Using an Active Object-Oriented Database Model (능동형 객체지향적 데이터베이스 모텔을 이용한 설계변경 개체 및 제약조건의 표현)

  • 도남철
    • Journal of Information Technology Applications and Management
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    • v.10 no.1
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    • pp.111-125
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    • 2003
  • This paper proposes a product data model that can express and enforce integrity constraints on product structure during engineering changes (ECs). The model adopts and extends an active object-oriented database model in order to Integrate IC data and their integrity constraints. Tightly integrated with product structure, It will enable designers to maintain and exchange consistent EC data throughout the product life cycle. In order to properly support operations for ECs, the model provides the data, operations, and Event-Condition-Action rules for nested ECs and simultaneous EC applications to multiple options. in addition, the EC objects proposed In the model integrate the data and Integrity constraints into a unified repository. This repository enables designers to access all EC data and integrity constraints through the product structure and relationships between EC objects. This paper also describes a prototype product data management system based on the proposed model In order to demonstrate its effectiveness.

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End-to-End Scheduling Method Considering 3-type RT-Data in Distributed Control Systems (분산 제어시스템에서 3가지 형태의 실시간 데이터를 고려하는 양극단 스케줄링 방법)

  • Kim, Hyoung-Yuk;Park, Hong-Seong
    • Proceedings of the KIEE Conference
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    • 2003.11b
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    • pp.311-314
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    • 2003
  • In recent years, distributed control systems(DCS) using fieldbus such as CAN have been applied to process systems but it is very difficult to design the DCS while guaranteeing the given end-to-end constraints such as precedence constraints, time constraints, and periods and priorities of tasks and messages. This paper presents a scheduling method to guarantee the given end-to-end constraints considering aperiodic, periodic and non-real-time message and task simultaneously. The presented scheduling method is the integrated one considering both tasks executed in each node and messages transmitted via the network and is designed to be applied to a general DCS that has multiple loops with several types of constraints, where each loop consists of sensor nodes with multiple sensors, actuator nodes with multiple actuators and controller nodes with multiple tasks.

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A Comparative Study of Korean and French Vowel Systems -An Experimental Phonetic and Phonological Perspective-

  • Kim, Seon-Jung;Lee, Eun-Yung
    • Speech Sciences
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    • v.8 no.1
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    • pp.53-66
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    • 2001
  • This paper aims to investigate the acoustic characteristics of the vowels attested in Korean and French and to seek a way of understanding them from a phonological point of view. We first compare the two vowel systems by measuring the actual frequencies of the formants using CSL. It is shown that the first and second formants vary in wider range in French compared to Korean. In order to understand the two vowel systems from a phonological point of view, we apply the theory of Licensing Constraints, proposed and developed by Kaye (1994), and Charette and Kaye (1994). We propose the licensing constraints placed upon the vowels both in Korean and French. For Korean, we propose the licensing constraints such that both elements I and U must be heads. For French, we claim the following licensing constraints: U in a headed expression must be head, A cannot be head, and Nothing can only license an expression A in it.

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An Optimality Criteria applied to The Plane Frames (평면 뼈대 구조물에 적용된 최적규준)

  • 정영식;김창규
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1995.10a
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    • pp.17-24
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    • 1995
  • This work proposes an optimality criteria applicable to the optimum design of plane frames. Stress constraints as well as displacement constraints are treated as behavioural constraints and thus the first order approximation of stress constraints is adopted. The design space of practical reinforced concrete frames with discrete design variables has been found to have many local minima, and thus it is desirable to find in advance the mathematical minimum, hopefully global, prior to starting to search a practical optimum design. By using the mathematical minimum as a trial design of any search algorithm, we may not full into a local minimum but apparently costly design. Therefore this work aims at establishing a mathematically rigorous method ⑴ by adopting first-order approximation of constraints, ⑵ by reducing the design space whenever minimum size restrictions become "active" and ⑶ by the of Newton-Raphson Method.

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