• Title/Summary/Keyword: Theory of Constraint

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Place Assimilation in OT

  • Lee, Sechang
    • Proceedings of the KSPS conference
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    • 1996.10a
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    • pp.109-116
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    • 1996
  • In this paper, I would like to explore the possibility that the nature of place assimilation can be captured in terms of the OCP within the Optimality Theory (Mccarthy & Prince 1999. 1995; Prince & Smolensky 1993). In derivational models, each assimilatory process would be expressed through a different autosegmental rule. However, what any such model misses is a clear generalization that all of those processes have the effect of avoiding a configuration in which two consonantal place nodes are adjacent across a syllable boundary, as illustrated in (1):(equation omitted) In a derivational model, it is a coincidence that across languages there are changes that have the result of modifying a structure of the form (1a) into the other structure that does not have adjacent consonantal place nodes (1b). OT allows us to express this effect through a constraint given in (2) that forbids adjacent place nodes: (2) OCP(PL): Adjacent place nodes are prohibited. At this point, then, a question arises as to how consonantal and vocalic place nodes are formally distinguished in the output for the purpose of applying the OCP(PL). Besides, the OCP(PL) would affect equally complex onsets and codas as well as coda-onset clusters in languages that have them such as English. To remedy this problem, following Mccarthy (1994), I assume that the canonical markedness constraint is a prohibition defined over no more than two segments, $\alpha$ and $\beta$: that is, $^{*}\{{\alpha, {\;}{\beta{\}$ with appropriate conditions imposed on $\alpha$ and $\beta$. I propose the OCP(PL) again in the following format (3) OCP(PL) (table omitted) $\alpha$ and $\beta$ are the target and the trigger of place assimilation, respectively. The '*' is a reminder that, in this format, constraints specify negative targets or prohibited configurations. Any structure matching the specifications is in violation of this constraint. Now, in correspondence terms, the meaning of the OCP(PL) is this: the constraint is violated if a consonantal place $\alpha$ is immediately followed by a consonantal place $\bebt$ in surface. One advantage of this format is that the OCP(PL) would also be invoked in dealing with place assimilation within complex coda (e.g., sink [si(equation omitted)k]): we can make the constraint scan the consonantal clusters only, excluding any intervening vowels. Finally, the onset clusters typically do not undergo place assimilation. I propose that the onsets be protected by certain constraint which ensures that the coda, not the onset loses the place feature.

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Workload Allocation Methods in Discrete Manufacturing Systems:Model and Optimization

  • Yingwen, Zheng
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.1362-1366
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    • 2003
  • Workload programming is allocating suitable workloads of production process according to the needs of products, which would minimize the total cost of both work and stock under some constraint conditions. In this paper, a production process flow chart of discrete manufacturing is presented by a Petri net, and the optimization model of workload-stock is established. An approach of the optimal workloads is provided by means of the integer matrix theory. An example is given to verify this method.

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Optimal size of the constraint buffer in TOC (제약자원 버퍼의 최적 크기 결정)

  • Go Si Geun
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2002.05a
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    • pp.476-480
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    • 2002
  • The theory of constraints (TOC) has become a valuable system in modern operations management. Using the ideas and methods of the TOC, companies can achieve a large reduction of work-in-process and finished-goods inventories, significant improvement in scheduling performance, and substantial earnings increase. The purpose of this paper is to calculate the optimal size of the time buffer which is used to accommodate disruptions in production processes and provide maximum productivity of capacity constrained resources. After the problem formulation in terms of single server queueing model, we observed the system behavior by sensitivity analyses.

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Velocity Measurement System Design Based on Quantization Error Constraint

  • Katsunori, Shida;Toyonori, Matsuda
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.86.1-86
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    • 2001
  • Combined with a counter, wheel or strip encoders which have equally divided markers are one of frequent measuring choices towards various applications in terms of cost, simplicity, and diversity of measurements, e.g., measuring displacement, velocity, acceleration, and so on. Often, velocity is measured by counting the series of reference clocks for a period of time which sensor-carrying device took for traveling two adjacent encoding markers. Quantizaion error of such that the disturbance caused by quantization error is under control. This paper identifies design issues, developes theory, and proposes a paradigm to design a velocity measurement system such ...

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Free Vibration of Beam-Columns on Non-Homogeneous Foundation (비균질 탄성지반 위에 놓인 보-기둥의 자유진동)

  • 이병구;오상진;이태은
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 1999.10c
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    • pp.206-211
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    • 1999
  • The purpose of this study is to investigate the natural frequencies and mode shapes of beam-columns on the non-homogeneous foundaion. The beam model is based on the classical Bernoulli-Euler beam theory. The linear foundation modulus is chosen as the non-homogeneous foundation in this study . The differentidal equation goeverning free vibrations of such beam-columns subjected to axial load is derived and solved numerically for calculting the natural frquencies and mode shapes. In numerical fivekinds of end constraint are considered, and the lowest four natural frquencies and corresponding mode shape are obtained as the non-dimensional forms.

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H$\infty$ Controllers for Symmetric Systems: A Theory for Attitude Control of Large Space Structures

  • Kim, Jae-Hoon;Sim, Eun-Sup
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.92.3-92
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    • 2001
  • This paper is concerned with robust attitude control of large space structures with collocated sensors and actuators. Since the transfer function matrices of such systems are symmetric, it seems suitable to employ symmetric controllers. This paper shows that it is true if no constraint is imposed on the orders of the controllers, but it is not true if the orders of the controllers are specified to be lower than that of the system to be controlled.

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A Three-Echelon Inventory Model for Repairable Items with Capacity Constraint (수리용량의 제한이 있는 수리가능한 부품의 3단계 재고시스템에 관한 연구)

  • 김지승
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.20 no.43
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    • pp.99-107
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    • 1997
  • We consider a multiechelon repairable-item inventory system where several bases are supported by a central depot and the external repair facilities. Unlike METRIC- based models, there are only a finite number of repair channels at each base, central depot and the external repair facilities. It is desired to find repair capacities and spares level which together guarantee a specified service level at minimum cost. Closed queueing network theory is used to model the stochastic process. The purpose of this paper is to derive the steady-state distributions of this system.

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A Study on the Lubrication Characteristics of Liquid Crystals (액정의 윤활특성에 관한 연구)

  • 임윤철;민지홍
    • Tribology and Lubricants
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    • v.8 no.1
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    • pp.30-37
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    • 1992
  • The displacement and pressure field of liquid crystals are analyzed numerically and compared with classical Reynolds theory. A plane slider bearing is employed as a simple example considering elasticity, permeability and splay effect which are the inherent characteristics of layered liquid crystals. Due to the geometric constraint of thin wedge and the strong anchoring behavior of the liquid crystals dislocations are inevitable. A finite element method is used to solve five coupled nonlinear equations. The load characteristics based on the pressure distribution along the gap shows that the liquid crystals can carry large load compared to the conventional lubricants.

Free Vibration Characteristics of Partially Embedded Piles (부분근입된 말뚝의 자유진동 특성)

  • 신성철;진태기;오상진;박광규
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.05a
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    • pp.435-440
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    • 2002
  • The free vibration of partially embedded piles is investigated. The pile model is based on the Bernoulli-Euler beam theory and the soil is idealized as a Winkler model for mathematical simplicity. The governing differential equation for the free vibrations of such members is solved numerically The piles with one typical end constraint (clamped/hinged/free) and the other hinged end with rotational spring are applied in numerical examples. The lowest three natural frequencies are calculated over a range of non-dimensional system parameters: the rotational spring parameter, the relative stiffness and the embedded ratio.

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Determination of flight route using optimal control theory (최적 제어 이론을 사용한 비행 경로 선정)

  • 김을곤
    • 제어로봇시스템학회:학술대회논문집
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    • 1992.10a
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    • pp.407-411
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    • 1992
  • A method for optimal route planning is presented with the assumption that the overall defended area is known in terms of threat potential function. This approach employes tangent plane to reduce the dimension of the state space for optimal programming problems with a state equality constraint. One-dimensional search algorithm is used to select the optimal route among the extermal fields which are obtained by integrating three differential equations from the initial values. In addition to being useful for the route planning through threat potential area, the trajectory planning will be suitable for general two-dimensional searching problems.

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