• 제목/요약/키워드: optimality

검색결과 665건 처리시간 0.021초

Distancing the Constraints on Syntactic Variations

  • Choi, Hye-Won
    • 한국언어정보학회지:언어와정보
    • /
    • 제11권1호
    • /
    • pp.77-96
    • /
    • 2007
  • This paper investigates syntactic variations in English such as Dative Alternation, Particle Inversion, and Object Postposition (Heavy NP Shift) within the framework of Optimality Theory, and shows that the same set of morphological, informational, and processing constraints affect all these variations. In particular, it shows that the variants that used to be regarded as ungrammatical are in fact used fairly often in reality, especially when processing or informational conditions are met, and therefore, grammatical judgment may not be always categorical but sometimes gradient. It is argued that the notion of distance in constraint ranking in stochastic OT can effectively explain the gradience and variability of grammaticality in the variation phenomena.

  • PDF

ANALYSIS AND COMPUTATIONS OF LEAST-SQUARES METHOD FOR OPTIMAL CONTROL PROBLEMS FOR THE STOKES EQUATIONS

  • Choi, Young-Mi;Kim, Sang-Dong;Lee, Hyung-Chun
    • 대한수학회지
    • /
    • 제46권5호
    • /
    • pp.1007-1025
    • /
    • 2009
  • First-order least-squares method of a distributed optimal control problem for the incompressible Stokes equations is considered. An optimality system for the optimal solution are reformulated to the equivalent first-order system by introducing the vorticity and then the least-squares functional corresponding to the system is defined in terms of the sum of the squared $H^{-1}$ and $L^2$ norms of the residual equations of the system. Finite element approximations are studied and optimal error estimates are obtained. Resulting linear system of the optimality system is symmetric and positive definite. The V-cycle multigrid method is applied to the system to test computational efficiency.

Optimality criteria based seismic design of multiple tuned-mass-dampers for the control of 3D irregular buildings

  • Daniel, Yael;Lavan, Oren
    • Earthquakes and Structures
    • /
    • 제8권1호
    • /
    • pp.77-100
    • /
    • 2015
  • Multiple tuned mass dampers (MTMDs) tuned to various frequencies have been shown to efficiently control the seismic response of structures where multiple modes are dominant. One example is irregular structures that are found more vulnerable than their symmetric counterparts. With the technology of MTMDs available, design and optimal design methodologies are required for application. Such a methodology, in the form of an analysis/redesign (A/R) scheme, has been previously presented by the authors while limiting responses of interest to allowable values, i.e., performance-based design (PBD). In this paper, the A/R procedure is modified based on formal optimality criteria, making it more cost efficient, as well as more computationally efficient. It is shown that by using the methodology presented herein, a desired performance level is successfully targeted by adding near-optimal amounts of mass at various locations and tuning the TMDs to dampen several of the structure's frequencies. This is done using analysis tools only.

An OT Analysis of Chinese Transliterations of English Place Names

  • Liang, Ce
    • International Journal of Advanced Culture Technology
    • /
    • 제7권2호
    • /
    • pp.137-143
    • /
    • 2019
  • This paper focuses on the analysis of the Chinese transliterations of English place names in the Optimality Theory (OT) [1]. Three groups of monosyllabic, disyllabic and multisyllabic English place names are analyzed to represent the hierarchical ranking of both Markedness and Faithfulness constraints in terms of sound epenthesis, which is one of the most important repair strategies named the Preservation Principle [2] devised to "preserve" every source segment (or sound) of the target place names. By doing so, this paper tries to answer the question of why sound epenthesis takes place in transliterating words between languages. With the help of the established ranking of the relevant constraints, this paper explains the process of sound epenthesis formally.

Multi-objective topology and geometry optimization of statically determinate beams

  • Kozikowska, Agata
    • Structural Engineering and Mechanics
    • /
    • 제70권3호
    • /
    • pp.367-380
    • /
    • 2019
  • The paper concerns topology and geometry optimization of statically determinate beams with arbitrary number of supports. The optimization problem is treated as a bi-criteria one, with the objectives of minimizing the absolute maximum bending moment and the maximum deflection for a uniform gravity load. The problem is formulated and solved using the Pareto optimality concept and the lexicographic ordering of the objectives. The non-dominated sorting genetic algorithm NSGA-II and the local search method are used for the optimization in the Pareto sense, whereas the genetic algorithm and the exhaustive search method for the lexicographic optimization. Trade-offs between objectives are examined and sets of Pareto-optimal solutions are provided for different topologies. Lexicographically optimal beams are found assuming that the maximum moment is a more important criterion. Exact formulas for locations and values of the maximum deflection are given for all lexicographically optimal beams of any topology and any number of supports. Topologies with lexicographically optimal geometries are classified into equivalence classes, and specific features of these classes are discussed. A qualitative principle of the division of topologies equivalent in terms of the maximum moment into topologies better and worse in terms of the maximum deflection is found.

Reduction of Unstressed Prevocalic /u/ in English

  • Hwangbo, Young-Shik
    • 영어영문학
    • /
    • 제55권6호
    • /
    • pp.1139-1161
    • /
    • 2009
  • This paper deals with the reduction of unstressed prevocalic /u/ and the appearance of /w/ which are observed in such words as ambiguity [ˌæm bǝ ˈgju: ǝ ti] - ambiguous [æm ˈbɪ gjǝ wǝs]. This phenomenon is recorded in Merriam-Webster Online Dictionary, Webster's Third New International Dictionary, Unabridged, and the draft revisions of Oxford English Dictionary Online. Since this phenomenon has not been studied in detail up to now, this paper aims 1) to collect the data related to the reduction of unstressed prevocalic /u/, 2) to classify them systematically, and 3) to explain the phenomenon in terms of Optimality Theory. In the course of analysis, Prevocalic Lengthening, which is crucial to the preservation of unstressed prevocalic /u/, is reinterpreted as one of the ways to prevent hiatus (annual /æ nju: ǝl/). /w/-insertion is another way to prevent hiatus (annual /æ njǝ wǝl/). In addition it is argued that prevocalic /u/ behaves differently from prevocalic /i/ due to the difference in the articulators involved.

후기 고대영어의 동질군 장모음화 분석 (An Analysis of Homorganic Cluster Lengthening in Late Old English)

  • 권영국
    • 영어영문학
    • /
    • 제55권4호
    • /
    • pp.719-744
    • /
    • 2009
  • This paper aims to reexamine Homorganic Cluster Lengthening in Late Old English whereby OE short vowels became lengthened before specific consonant clusters such as /-ld, -nd, -mb, -rd, -rð, -ng, -rz/. As for the motivation for this apparently odd-looking sound change, I propose that it was the result of phonologization of the phonetic lengthening of syllables containing resonants homorganic with a following voiced obstruent. Adopting Luick's (1898) view of "resonant+voiced homorganic obstruent" phonologically as a single coda, I show that Homorganic Cluster Lengthening is in fact a natural sound change that can be explained with the proper postulation of a few quantity-related universal constraints within the framework of the Optimality Theory. The fact that the constraints and their ranking as posited in this paper can also account for Pre-Cluster Shortening points to the validity of my approach in the analysis of other quantity changes in Middle English.

복합실험기준의 설정: 모형과 분산구조 (Composite Design Criteria : Model and Variance)

  • 김영일
    • 응용통계연구
    • /
    • 제13권2호
    • /
    • pp.393-405
    • /
    • 2000
  • 원래 최적실험의 이론은 주어진 모형과 그에 따른 가정에 기초하여 발달되었기 때문에 하나의 최적실험기준이 실험이 가족 있는 여러 목적을 모두 반영하는 것이 무리이다. 따라서 실험자가 다목적 실험기준의 필요성을 느끼는 경우에는 종종 여러 최적실험 기준들의 균형을 이루는 방법을 통해 이러한 문제가 다루어진다. 본 연구에서는 이 분산 구조를 가지고 있는 모형을 예를 들어 복합적인 실험기준들을 알아본다. 왜냐하면 이분산인 경우 D-최적과 G-최적실험간의 동격이론은 더 이상 성립되지 않음에 따라 두 실험기준의 특징은 현격하게 구분되어지기 때문이다. 제약조건최적실험, 결합최적실험, 그리고 minimax 설험방법을 통한 실험기준들간의 균형을 꾀하여 보았다. 처음 두 방법은 실험자의 주관이 반영되어 실제적으로 매우 세심한 주의가 필요한 반면, minimax는 그러한 점을 해소하였다고 본다. 또한 이를 확장하여 오차의 이분산 구조에 대한 불확실성이 존재할 때 적용될수 있는 두 가지 실험기준도 마련하여 보았다. 간단한 알고리즘과 결어를 첨부하였다.

  • PDF