• Title/Summary/Keyword: constraint-based

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Transformation of Constraint-based Analyses for Efficient Analysis of Java Programs (Java 프로그램의 효율적인 분석을 위한 집합-기반 분석의 변환)

  • Jo, Jang-Wu;Chang, Byeong-Mo
    • Journal of KIISE:Software and Applications
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    • v.29 no.7
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    • pp.510-520
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    • 2002
  • This paper proposes a transformation-based approach to design constraint-based analyses for Java at a coarser granularity. In this approach, we design a less or equally precise but more efficient version of an original analysis by transforming the original construction rules into new ones. As applications of this rule transformation, we provide two instances of analysis design by rule-transformation. The first one designs a sparse version of class analysis for Java and the second one deals with a sparse exception analysis for Java. Both are designed based on method-level, and the sparse exception analysis is shown to give the same information for every method as the original analysis.

A Framework of Internet Shopping Decision Making Based on Semantic Web Constraint Language (의미망 제약식언어를 기반으로 한 인터넷 쇼핑 의사결정 틀)

  • Lee, Myung-Jin;Kim, Hak-Jin;Kim, Woo-Ju
    • Journal of the Korean Operations Research and Management Science Society
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    • v.33 no.3
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    • pp.29-42
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    • 2008
  • Semantic Web society initially focused only on data but has gradually moved toward knowledge. Recently rule beyond ontology has emerged as a key element of the Semantic Web. All of these activities are obviously aiming at making data and knowledge on the Web sharable and reusable between various entities around the world. If one of ultimate visions of the Semantic Web is to increase human's decision making quality assisted by machines, there is a missing but important part to be shared and reused. It is knowledge about constraints on data and concepts represented by ontology which should be emphasized more. In this paper, we propose Semantic Web Constraint Language (SWCL) based on OWL and show how effective SWCL can be in representing and solving an internet shopper's decision making problem by an implementation of a shopping agent in the Semantic Web environment.

Robust Predictive Control of Uncertain Nonlinear System With Constrained Input

  • Son, Won-Kee;Park, Jin-Young;Kwon, Oh-Kyu
    • Transactions on Control, Automation and Systems Engineering
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    • v.4 no.4
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    • pp.289-295
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    • 2002
  • In this paper, a linear matrix inequality(LMI)-based robust control method, which combines model predictive control(MPC) with the feedback linearization(FL), is presented for constrained nonlinear systems with parameter uncertainty. The design procedures consist of the following 3 steps: Polytopic description of nonlinear system with a parameter uncertainty via FL, Mapping of actual input constraint by FL into constraint on new input of linearized system, Optimization of the constrained MPC problem based on LMI. To verify the performance and usefulness of the control method proposed in this paper, some simulations with application to a flexible single link manipulator are performed.

Enhancement of Computational Efficiency of Reliability Optimization Method by Approximate Evaluation of Sub-Optimization Problem (부 최적화 문제의 근사적인 계산을 통한 신뢰도 최적설계 방범의 효율개선)

  • Jeong, Do-Hyeon;Lee, Byeong-Chae
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.25 no.10
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    • pp.1597-1604
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    • 2001
  • Alternative computational scheme is presented fur reliability based optimal design using a modified advanced first order second moment (AFOSH) method. Both design variables and design parameters are considered as random variables about their nominal values. Each probability constraint is transformed into a sub -optimization problem and then is resolved with the modified Hasofer- Lind-Rackwitz-Fiessler (HL-RF) method for computational efficiency and convergence. A method of design sensitivity analysis for probability constraint is presented and tested through simple examples. The suggested method is examined by solving several examples and the results are compared with those of other methods.

A controller design using modal decomposition of matrix pencil

  • Shibasato, Koki;Shiotsuki, Tetsuo;Kawaji, Shigeyasu
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.492-492
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    • 2000
  • This paper proposes LQ optimal controller design method based on the modal decomposition. Here, the design problem of linear time-invariant systems is considered by using pencil model. The mathematical model based on matrix pencil is one of the most general representation of the system. By adding some conditions the model can be reduced to traditional system models. In pencil model, the state feedback is considered as an algebraic constraint between the state variable and the control input variable. The algebraic constraint on pencil model is called purely static mode, and is included in infinite mode. Therefore, the information of the constant gain controller is included in the purely static mode of the augmented system which consists of the plant and the control conditions. We pay attention to the coordinate transformation matrix, and LQ optimal controller is derived from the algebraic constraint of the internal variable. The proposed method is applied to the numerical examples, and the results are verified.

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A Numerical Study Using Micromechanics Model for Metal Matrix Composites (금속복합재료의 미세구조역학 모델을 이용한 수치해석적 연구)

  • 김홍건;장성호;장대성;정수경
    • Proceedings of the Materials Research Society of Korea Conference
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    • 1994.11a
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    • pp.133-136
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    • 1994
  • A microcechanical analysis based on the single fiber model has studied in the standpoint of stress-strain hysteresis response. A comparative study of constraint and unconstraint effects ha been taken into account to investigate includes the stress grouping technique to evaluate the domain-based field quantities. Results indicated that the development of significant fiber stresses both for the tensile and compressive loading, due to the constraint effects, provides an important contribution to the composited strengthening

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Optimization of RC Piers Based on Efficient Reanalysis Technique (효율적인 재해석 기법에 의한 RC 교각의 최적설계)

  • 조효남;민대홍;신만규
    • Proceedings of the Korea Concrete Institute Conference
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    • 2000.10a
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    • pp.199-204
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    • 2000
  • In this study, an optimum design algorithm using efficient reanalysis is proposed for seismic design of RC Piers. The proposed algorithm for optimization of RC Piers is based on efficient reanalysis technique. Considering structural behavior of RC Piers, several other approximation techniques, such as artificial constraint deletion is introduced to increase the efficiency of optimization. The efficiency and robustness of the proposed algorithm increase the proposed reanalysis technique is demonstrated by comparing it with a conventional optimization algorithm. A few of design examples are optimized to show the applicability of the proposed algorithm.

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Outfitting and Painting Scheduling for Shipbuilding Using Constraint Satisfaction (제약 만족 기법을 이용한 기관의장과 선행도장의 일정계획)

  • Kim, Ki-Dong;Lee, Bo-Hurn
    • Journal of Industrial Technology
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    • v.26 no.A
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    • pp.173-180
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    • 2006
  • Scheduling for shipbuilding processes has many alternative solutions since it has long time horizon and handles many jobs. In this paper, an shipbuilding scheduling system for outfitting and painting is presented based on constraint satisfaction techniques(CST). We provide a field based model and an efficient solution methodology by using ILOG Scheduler and Solver. ILOG Solver support extensive optimization goals easily. We do verify the improvement and efficiency of the schedule generated by the scheduling system presented in this paper.

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ENHANCEMENT THE SOUND TRANSMISSION LOSS OF POROELASTIC LININGS

  • Song, B.Heuk-Jin;Bolton, J.Stuart
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2000.06a
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    • pp.606-611
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    • 2000
  • It has been noted that the low frequency absorption coefficient of a porous sample placed in a standing wave tube is affected by the nature of the sample's edge constraint. The edge constraint has the effect of stiffening the solid phase of the sample, which itself can be strongly coupled to the material's fluid phase, and hence the incident sound field, by viscous means at low frequencies. In recent work it has also been shown that such a circumferential constraint causes the low frequency transmission loss of a layer of fibrous material to approach a finite low frequency limit that is proportional to the flow resistance of the layer and which is substantially higher than that of an unconstrained sample of the same material. However, it was also found that the benefit of the circumferential edge constraint was reduced in a transitional frequency range by a shearing resonance of the sample. Here it will be shown that the effect of that resonance can be mitigated or eliminated by adding additional axial and radial constraints running through the sample. It will also be shown that the constraint effect can be modeled closely by using a finite element procedure based on the Biot poroelastic theory. Implications for low frequency barrier design are also discussed.

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Consideration of Constraint Effect of Surface Cracks Under PTS Conditions Using J-Q Approach (PTS 사고하에서 J-Q해석법을 이용한 표면균열의 구속효과 고찰)

  • Kim, Jin-Su;Choe, Jae-Bung;Kim, Yun-Jae;Kim, Yeong-Jin
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.1
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    • pp.105-112
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    • 2002
  • In recent years, the integrity of reactor Pressure Vessel(RPV) under pressurized thermal shock (PTS) accident has been treated as one of the most critical issues. Under PTS condition, the combination of thermal and mechanical stress by steep temperature gradient and internal pressure causes considerably high tensile stress at the inside of RPV wall. As a result, cracks on inner surface of RPV may experience elastic-plastic behavior which can be characterized by J-integral. In such a case, however, J-integral may possibly lose its vapidity due to the constraint effect. The degree of constraint effect is influenced by the loading mode, crack geometry and material properties. In this paper, in order to investigate the effect of clad thickness and crack geometry on constraint effect, three dimensional finite element analyses were performed for various surface cracks. Total of 27 crack geometries were analyzed and results were presented by a two-parameter characterization based on the J-integral and the f-stress.