• 제목/요약/키워드: new constraints

검색결과 1,221건 처리시간 0.033초

Coherent Combination of Baryon Acoustic Oscillation Statistics and Peculiar Velocity Measurements from Redshift Survey

  • 송용선
    • 천문학회보
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    • 제36권1호
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    • pp.46.1-46.1
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    • 2011
  • New statistical method is proposed to coherently combine Baryon Acoustic Oscillation statistics (BAO) and peculiar velocity measurements exploiting decomposed density--density and velocity--velocity spectra in real space from the observed redshift distortions in redshift space, 1) to achieve stronger dark energy constraints, sigma(w)=0.06 and sigma(w_a)=0.20, which are enhanced from BAO or velocity measurements alone, and 2) to cross--check consistency of dark energy constraints from two different approaches; BAO as geometrical measurements and peculiar velocity as large scale structure formation observables.

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An Optimality-Based Analysis of Relative Positioning of Wh-related Prepositions in English

  • Han-gyoo, Khym
    • International Journal of Advanced Culture Technology
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    • 제10권4호
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    • pp.576-582
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    • 2022
  • In this paper, we discuss the relative positioning of Wh-related English prepositions in a Wh-interrogative construction within the Optimality Theory [1-2]. By employing the two key constraints such as *Prep-Str and Align which are developed for the positioning of Wh-related prepositions from Romance languages such as French and Italian [3] and for the positioning of Wh-related prepositions from the middle English prose from 1500 to 1900 [4-6], and by slightly modifying the constraint hierarchy of *Prep-STR >>Align into **PrepSTR <<>>Align, Choi argues that his new theory can properly explain the unique behaviors of English Whrelated prepositions being able to take two 'optional' operations such as pied-piping and stranding to find legitimate landing sites in a Wh-interrogative construction [7]. However, this new analysis again reveals the following critical problems: (1) Unlike the 'light' English Wh-related prepositions which can two optional operations for legitimate landing sites in a Wh-interrogative construction, 'heavy' Wh-related English prepositions are not allowed to have such two options: they take just one option of pied-piping only. Thus, (2) his argumentation based on the existing constraints and the modified constraint hierarchy is neither general enough nor proper to explain the issue of the relative positioning for all English Wh-related preposition cases. To include such exceptional syntactic property of the 'heavy' preposition cases within the Optimality Theory, we suggest a new constraint of *HPrep-STR ranked at the highest position of the constraint hierarchy to disallow a 'heavy' or multi-syllabic Wh-related English preposition to stay alone at the end of a sentence. The new final hierarchy of constraints we suggest to explain the exceptional positioning of 'heavy' Wh-related prepositions together with the other 'light' Wh-related prepositions in English Wh-interrogative construction will be as follows: *HPrep-STR>>Align<<>>*Prep-STR.

파라메트릭 접근방법에 의한 특징형상을 이용한 모델링 (A Parametric Approach to Feature-based Modeling)

  • 이재열;김광수
    • 한국CDE학회논문집
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    • 제1권3호
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    • pp.242-256
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    • 1996
  • Although feature-based design is a promising approach to fully integrating CAD/CAM, current feature-based design approaches seldom provide methodologies to easily define and design features. This paper proposes a new approach to integrating parametric design with feature-based design to overcome those limitations by globally decomposing a design into a set of features and locally defining and positioning each feature by geometric constraints. Each feature is defined as a parametric shape which consists of a feature section, attributes, and a set of constraints. The generalized sketching and sweeping techniques are used to simplify the process of designing features. The proposed approach is knowledge-based and its computational efficiency in geometric reasoning is improved greatly. Parametrically designed features not only have the advantage of allowing users to efficiently perform design changes, but also provide designers with a natural design environment in which they can do their work more naturally and creatively.

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능동적 객체지향 데이타베이스에서 사용자 정의 제약조건의 역방향 전달에 관한 연구 (Backward Propagation of User-Defined Integrity Constraints On Active Object-Oriented Database)

  • 도남철;최인준
    • 정보기술과데이타베이스저널
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    • 제1권1호
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    • pp.63-81
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    • 1994
  • The trigger mechanism in active object-oriented database systems is known to be a good tool for describing user-defined integrity constraints. It cannot adequately support, however, certain integrity constrains specified on the objects in class composition hierarchy. Those are the cases where the constraints must be maintained in the forward direction along the composition hierarchy as well as in the backward direction We call theses kinds of problems "backward propagation problem" and investigate several ways to resolve them using the currently available techniques. Based on them, a new constructor, called CONSTRAIN $T^{cch}$, is proposed. The constructor can be realized with enhanced facilities for active OODBMS which we recommend in this paper.d facilities for active OODBMS which we recommend in this paper.r.

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퍼지 시스템을 이용한 이동로봇의 궤적제어 (Tracking Control for Mobile Robot Based on Fuzzy Systems)

  • 박재훼;이만형
    • 제어로봇시스템학회논문지
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    • 제9권6호
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    • pp.466-472
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    • 2003
  • This paper describes a tracking control for the mobile robot based on fuzzy systems. Since the mobile robot has the nonholonomic constraints, these constraints should be considered to design a tracking controller for the mobile robot. One of the well-known tracking controllers for the mobile robot is the back-stepping controller. The conventional back-stepping controller includes the dynamics and kinematics of the mobile robot. The conventional back-stepping controller is affected by the derived velocity reference by a kinematic controller. To improve the performance of the conventional back-stepping controller, this paper uses the fuzzy systems known as the nonlinear controller. The new velocity reference for the back-stepping controller is derived through the fuzzy inference. Fuzzy rules are selected for gains of the kinematic controller. The produced velocity reference has properly considered the varying reference trajectories. Simulation results show that the proposed controller is more robust than the conventional back-stepping controller.

프로세스 구조 제약조건과 사회적 관계를 이용한 비즈니스 프로세스 모델링 방법론 (Business Process Modeling using Process Structural Constraints and Social Relations)

  • 유영웅;김승;배혜림
    • 산업공학
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    • 제25권3호
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    • pp.300-308
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    • 2012
  • For convenient business process modeling we propose a mathematical approach to obtain appropriate process structures. In this paper, we define business process structural constraints, on which basis, using Social Network Analysis (SNA), we analyze the frequency of handover occurrences among performers in social network. We here present, therefrom, a new, mathematical approach to business process modeling that proceeds by identifying the social relations among activities.

Real Time Optimal Control of Mechanical Systems

  • Park, Jin-Bae;Shohei, Niwa
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2001년도 ICCAS
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    • pp.108.3-108
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    • 2001
  • In this work, we consider a real time optimal control problem of mechanical systems with restrictions for actuators i.e. input restrictions and constraints for the movable area i.e. state constraints. First, we formulate an optimal control problem which evaluates the cost function for a finite time horizon with input restrictions and state constraints of a wheeled vehicle as an example of mechanical systems. In this problem, the differentiability of the cost function is not required and this implies that the problem cannot be solved analytically. Therefore, in this work, we use an optimization method to solve the optimal control problem and a new real time optimization method is proposed to solve the problem. In this method, we provide a parameter that indicates the ...

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여러 개의 FPGA 칩을 위한 대규모 회로의 분할 (Partitioning of large-circuits for multiple FPGAs)

  • 김정희;신현철
    • 전자공학회논문지A
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    • 제32A권4호
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    • pp.85-92
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    • 1995
  • A new partitioning algorithm has been developed to implement a large circuit by using multiple field programmable gate array (FPGA) chips. While the conventional partitioning is to minimze the number of nets cut under size constraints, partitioning for multiple FPGAs has several additional constraints so that each partitioned subcircuit can be implemented in a FPGA chip. To obtain satisfactory results under the constraints, the partitioning is performed in two steps whhich are the intial partitioning for global optimization and the iterative partitioning improvements for constraint satisfaction. Experismental results using the MCNC benchmark examples show that our partition method produces better results thatn those of other recent approaches on the average.

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Envelope empirical likelihood ratio for the difference of two location parameters with constraints of symmetry

  • Kim, Kyoung-Mi;Zhou, Mai
    • 한국데이터정보과학회:학술대회논문집
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    • 한국데이터정보과학회 2002년도 춘계학술대회
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    • pp.51-73
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    • 2002
  • Empirical likelihood ratio method is a new technique in nonparametric inference developed by A. Owen (1988, 2001). Sometimes empirical likelihood has difficulties to define itself. As such a case in point, we discuss the way to define a modified empirical likelihood for the location of symmetry using well-known points of symmetry as a side conditions. The side condition of symmetry is defined through a finite subset of the infinite set of constraints. The modified empirical likelihood under symmetry studied in this paper is to construct a constrained parameter space $\theta+$ of distributions imposing known symmetry as side information. We show that the usual asymptotic theory (Wilks theorem) still hold for the empirical likelihood ratio on the constrained parameter space and the asymptotic distribution of the empirical NPMLE of difference of two symmetric points is obtained.

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A New Technique for Solving Optimal Control Problems of the Time-delayed Systems

  • Ghomanjani, Fateme
    • Kyungpook Mathematical Journal
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    • 제58권2호
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    • pp.333-346
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    • 2018
  • An approximation scheme utilizing Bezier curves is considered for solving time-delayed optimal control problems with terminal inequality constraints. First, the problem is transformed, using a $P{\acute{a}}de$ approximation, to one without a time-delayed argument. Terminal inequality constraints, if they exist, are converted to equality constraints. A computational method based on Bezier curves in the time domain is then proposed for solving the obtained non-delay optimal control problem. Numerical examples are introduced to verify the efficiency and accuracy of the proposed technique. The findings demonstrate that the proposed method is accurate and easy to implement.