• 제목/요약/키워드: transformations

검색결과 1,013건 처리시간 0.027초

Modeling of GN type III with MDD for a thermoelectric solid subjected to a moving heat source

  • Ezzat, Magdy A.
    • Geomechanics and Engineering
    • /
    • 제23권4호
    • /
    • pp.393-403
    • /
    • 2020
  • We design the Green-Naghdi model type III (GN-III) with widespread thermoelasticity for a thermoelectric half space using a memory-dependent derivative rule (MDD). Laplace transformations and state-space techniques are used in order to find the general solution for any set of limit conditions. A basic question of heat shock charging half space and a traction-free surface was added to the formulation in the present situation of a traveling heat source with consistent heating speed and ramp-type heating. The Laplace reverse transformations are numerically recorded. There are called the impacts of several calculations of the figure of the value, heat source spead, MDD parameters, magnetic number and the parameters of the ramping period.

On Some Spaces Isomorphic to the Space of Absolutely q-summable Double Sequences

  • Capan, Husamettin;Basar, Feyzi
    • Kyungpook Mathematical Journal
    • /
    • 제58권2호
    • /
    • pp.271-289
    • /
    • 2018
  • Let 0 < q < ${\infty}$. In this study, we introduce the spaces ${\mathcal{BV}}_q$ and ${\mathcal{LS}}_q$ of q-bounded variation double sequences and q-summable double series as the domain of four-dimensional backward difference matrix ${\Delta}$ and summation matrix S in the space ${\mathcal{L}}_q$ of absolutely q-summable double sequences, respectively. Also, we determine their ${\alpha}$- and ${\beta}-duals$ and give the characterizations of some classes of four-dimensional matrix transformations in the case 0 < q ${\leq}$ 1.

우리나라 주요지점에 있어서의 강우해석에 관한 수문통계학적 연구

  • 이원환
    • 물과 미래
    • /
    • 제5권2호
    • /
    • pp.30-43
    • /
    • 1972
  • The paper describes on the hydrologic analysis of point rainfall data of the three major areas, such as in Seoul, Pusan and Taegu. Scheme of the paper is analyzed five research cases. Contents of the analysis are carried out five kinds of transformed variables for determination of rainfall distribution types and two kinds of reliability tests on unusual(extraordinary) values each rainfall durations:short durations, long durations, long durations, monthly and yearly. Rainfall depth probability had been computed methods of hydrologic amounts analysis namely logarithmic transformations or Gumbel-Chow method and so on, but in this paper it is calculated log xi, n-square root transformations by using normal distribution function and normalization of rainfall distributions is examined graphical tests and $X^2-test$(chi-square test). Furthermore, rainfall depth probability is calculated taking into account the safty factors of project life of hydraulic structures. We think it is advanced contents that considering priceless experiences, the life of structures, conditions and more problems of planning engineers and designers, proposed rainfall amounts(proposed values) are presented charts or figures.

  • PDF

Development of Query Transformation Method by Cost Optimization

  • Altayeva, Aigerim Bakatkaliyevna;Yoon, Youngmi;Cho, Young Im
    • International Journal of Fuzzy Logic and Intelligent Systems
    • /
    • 제16권1호
    • /
    • pp.36-43
    • /
    • 2016
  • The transformation time among queries in the database management system (DBMS) is responsible for the execution time of users' queries, because a conventional DBMS does not consider the transformation cost when queries are transformed for execution. To reduce the transformation time (cost reduction) during execution, we propose an optimal query transformation method by exploring queries from a cost-based point of view. This cost-based point of view means considering the cost whenever queries are transformed for execution. Toward that end, we explore and compare set off heuristic, linear, and exhaustive cost-based transformations. Further, we describe practical methods of cost-based transformation integration and some query transformation problems. Our results show that, some cost-based transformations significantly improve query execution time. For instance, linear and heuristic transformed queries work 43% and 74% better than exhaustive queries.

A View on the Validity of Central Limit Theorem: An Empirical Study Using Random Samples from Uniform Distribution

  • Lee, Chanmi;Kim, Seungah;Jeong, Jaesik
    • Communications for Statistical Applications and Methods
    • /
    • 제21권6호
    • /
    • pp.539-559
    • /
    • 2014
  • We derive the exact distribution of summation for random samples from uniform distribution and then compare the exact distribution with the approximated normal distribution obtained by the central limit theorem. To check the similarity between two distributions, we consider five existing normality tests based on the difference between the target normal distribution and empirical distribution: Anderson-Darling test, Kolmogorov-Smirnov test, Cramer-von Mises test, Shapiro-Wilk test and Shaprio-Francia test. For the purpose of comparison, those normality tests are applied to the simulated data. It can sometimes be difficult to derive an exact distribution. Thus, we try two different transformations to find out which transform is easier to get the exact distribution in terms of calculation complexity. We compare two transformations and comment on the advantages and disadvantages for each transformation.

Omnibus tests for multivariate normality based on Mardia's skewness and kurtosis using normalizing transformation

  • Kim, Namhyun
    • Communications for Statistical Applications and Methods
    • /
    • 제27권5호
    • /
    • pp.501-510
    • /
    • 2020
  • Mardia (Biometrika, 57, 519-530, 1970) defined measures of multivariate skewness and kurtosis. Based on these measures, omnibus test statistics of multivariate normality are proposed using normalizing transformations. The transformations we consider are normal approximation and a Wilson-Hilferty transformation. The normalizing transformation proposed by Enomoto et al. (Communications in Statistics-Simulation and Computation, 49, 684-698, 2019) for the Mardia's kurtosis is also considered. A comparison of power is conducted by a simulation study. As a result, sum of squares of the normal approximation to the Mardia's skewness and the Enomoto's normalizing transformation to the Mardia's kurtosis seems to have relatively good power over the alternatives that are considered.

A Comparison of Entrepreneurism and Internationalization between Asian World-Class Universities

  • Timberman, Alex
    • Asian Journal of Innovation and Policy
    • /
    • 제2권2호
    • /
    • pp.173-193
    • /
    • 2013
  • This paper surveys the development of Asian universities and their path towards the American entrepreneurial type. The paper suggests Asian universities used internationalization and entrepreneurial missions to follow older American entrepreneurial universities with success towards world-class university status. Current studies are lacking on covering the significance of internationalization at Asian entrepreneurial universities and offer few typologies on the diverse Asian transformations of the past approximate thirty years. Thus, paper proposes a theoretical framework linking internationalization with innovation and classifies into 3 types, the various Asian entrepreneurial university transformations from an international comparative perspective. It then examines the type using case studies.

PI 제어기의 내부원리를 이용한 PWM AC-DC 컨버터의 새로운 전류제어 (Novel current control for PWM AC-DC converter using internal principle of PI controller)

  • 허태원;황영민;김영빈;이현우;우정인
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 1998년도 하계학술대회 논문집 F
    • /
    • pp.1944-1946
    • /
    • 1998
  • This paper presents a novel current control system to eliminate the steady state control error for PWM AC-DC converter. A general mathematical model of the converter which is represented as a state-space model is established. The state-space model is used for the simulation of converter with the proposed tracking control system of sinusoidal current. In this system, a novel current control which do not require coordinate transformations using internal principle of PI controller is described. It is proved that the steady state deviation reduce to zero through a transfer function of source current control system. Finally, simulations show good source current control characteristics by means of a simplified control system which do not require coordinate transformations.

  • PDF

Students' Growth of Understanding with Technology Experience from the Perspective of Representation

  • Jung, In-Chul
    • 한국수학교육학회지시리즈E:수학교육논문집
    • /
    • 제15권
    • /
    • pp.281-286
    • /
    • 2003
  • The primary purpose of this study was to investigate how and to what extent 'representations' affect the students' understanding and the growth of understanding in a technology [GSP]-based collegiate mathematics classroom. There are three themes related as frames of the study along with this purpose, which are mentioned in the first chapter and extended in the second chapter: technology in mathematics education; images on computer screen - visualization and representation; understanding and growth of understanding. Three research questions guided this study: 1) How do students present each component of representations when they study 'transformations' in a technology [GSP]-based classroom? If there is any difference between the first and second presentation for each component, how are they different?; 2) How and to what extent do representations affect the students' understanding and the growth of understanding in a technology [GSP]-based classroom?; What types of benefits and obstacles are there when students study 'transformations' in a technology [GSP]-based classroom?

  • PDF

DYNAMICAL PROPERTIES OF A FAMILY OF SKEW PRODUCTS WITH THREE PARAMETERS

  • Ahn, Young-Ho
    • 호남수학학술지
    • /
    • 제31권4호
    • /
    • pp.591-599
    • /
    • 2009
  • For given ${\alpha},{\omega}\;{\in}\;{\mathbb{R}}$ and ${\beta}$ > 1, let $T_{{\beta},{\alpha},{\omega}}$ be the skew-product transformation on the torus, [0, 1) ${\times}$ [0, 1) defined by (x, y) ${\longmapsto}\;({\beta}x,y+{\alpha}x+{\omega})$ (mod 1). In this paper, we give a criterion of ergodicity and weakly mixing for the transformation $T_{{\beta},{\alpha},{\omega}}$ when the natural extension of the given ${\beta}$-transformation can be viewed as a generalized baker's transformation, i.e., they flatten and stretch and then cut and stack a two-dimensional domain. This is a generalization of theorems in [10].