• 제목/요약/키워드: sums

검색결과 594건 처리시간 0.031초

APPLICATION OF A CERTAIN FAMILY OF HYPERGEOMETRIC SUMMATION FORMULAS ASSOCIATED WITH PSI AND ZETA FUNCTIONS

  • Choi, June-Sang;H.M.Srivastava;Kim, Yong-Sup
    • 대한수학회논문집
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    • 제16권2호
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    • pp.319-332
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    • 2001
  • The main object of this paper is first to give tow contiguous analogues of a well-known hypergeometric summation formula for $_2$F$_1$(1/2). We then apply each of these analogues with a view to evaluating the sums of several classes of series in terms of Psi(or Digamma) and the Zeta functions. Relevant connections of the series identities presented here with those given elsewhere are also pointed out.

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Two-transistor 포워드 컨버터에서 소프트 스위칭 기법의 손실 분석 (Loss Analyses of Soft Switching Techniques for Two-transistor Forward Converter)

  • 김만고
    • 전력전자학회논문지
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    • 제6권5호
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    • pp.453-459
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    • 2001
  • 본 논문에서는 Two-transistor 포워드 컨버터에서 사용 가능한 기존의 소프트 스위칭 기법과 새로운 소프트 스위칭 기법의 손실 분석을 수행한다. 두 트랜지스터에서 발생하는 스너버 전류에 의한 트랜지스터 손실과 내부 커패시터에 의한 턴-온 손실을 유도하고, 각각의 트랜지스터에서 발생하는 전체 손실을 계산한다. 손실 계산을 통해 기존의 소프트 스위칭 기법에서는 두 트랜지스터에서 발생하는 손실이 상이함을 보이고, 새로운 소프트 스위칭 기법에서는 손실이 적으면서도 두 트랜지스터에서의 손실이 고르게 발생함을 알 수 있다. 그리하여 제안된 소프트 스위칭 스너버를 사용하여 고른 열분포와 향상된 신뢰도를 얻을 수 있음을 보인다.

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Image classification methods applicable multiple satellite imagery

  • Jeong, Jae-Jun;Kim, Kyung-Ok;Lee, Jong-Hun
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2002년도 Proceedings of International Symposium on Remote Sensing
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    • pp.81-81
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    • 2002
  • Classification is considered as one of the processes of extracting attributes from satellite imagery and is one of the usual functions in the commercial satellite image processing software. Accuracy of classification plays a key role in deciding the usage of its results. Many tremendous efforts far the higher accuracy have been done in such fields; training area selection, classification algorithm. Our research is one of these effort in different manners. In this research, we conduct classification using multiple satellite image data and evidential approach. We statistically consider the posterior probabilities and certainty in maximum likelihood classification and methodologically Dempster's orthogonal sums. Unfortunately, accuracy for the whole data sets has not assessed yet, but accuracy assessments in training fields and check fields shows accuracy improvement over 10% in overall accuracy and over 0.1 in kappa index.

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불균형 이원분류자료 분석과 가설검정 (Analysis of variance and hypothesis testing with unbalanced data)

  • 장석환
    • 응용통계연구
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    • 제3권2호
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    • pp.39-53
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    • 1990
  • 분균형자료의 분석과 가설검정을 위하여 표본수 $n_{ij}$$n_{ij}>0$인 경우와 ${n_{1j}}{/geq}0$인 경우의 인위적인 이원분류자료를 써서 여러 가지 모형하에서 주효과와 교호작용에 대한 변동을 계산하는 방법을 Searle의 R($\mid$)표기법을 이용하여 검토하였고 이들 변동과 일반적으로 널리 쓰이는 가설과의 관계를 실증적으로 재검토하였다.

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Collapsibility and Suppression for Cumulative Logistic Model

  • Hong, Chong-Sun;Kim, Kil-Tae
    • Communications for Statistical Applications and Methods
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    • 제12권2호
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    • pp.313-322
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    • 2005
  • In this paper, we discuss suppression for logistic regression model. Suppression for linear regression model was defined as the relationship among sums of squared for regression as well as correlation coefficients of. variables. Since it is not common to obtain simple correlation coefficient for binary response variable of logistic model, we consider cumulative logistic models with multinomial and ordinal response variables rather than usual logistic model. As number of category of a response variable for the cumulative logistic model gets collapsed into binary, it is found that suppressions for these logistic models are changed. These suppression results for cumulative logistic models are discussed and compared with those of linear model.

On Generalized FI-extending Modules

  • Yucel, Canan Celep
    • Kyungpook Mathematical Journal
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    • 제60권1호
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    • pp.45-51
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    • 2020
  • A module M is called FI-extending if every fully invariant submodule of M is essential in a direct summand of M. In this work, we define a module M to be generalized FI-extending (GFI-extending) if for any fully invariant submodule N of M, there exists a direct summand D of M such that N ≤ D and that D/N is singular. The classes of FI-extending modules and singular modules are properly contained in the class of GFI-extending modules. We first develop basic properties of this newly defined class of modules in the general module setting. Then, the GFI-extending property is shown to carry over to matrix rings. Finally, we show that the class of GFI-extending modules is closed under direct sums but not under direct summands. However, it is proved that direct summands are GFI-extending under certain restrictions.

ON THE PRUSS EXTENSION OF THE HSU-ROBBINS-ERD S THEOREM

  • Sung, Soo-Hak
    • 대한수학회보
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    • 제36권2호
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    • pp.305-314
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    • 1999
  • The Hsu-Robbins-erd s theorem states that if {$X_m,n\geq1$} is a sequence of independent and identically distributed random variables, then ${EX_1}^2<\infty$ and $EX_1$=0 if and only if ${\sum_{n=1}}^\infty\;P($\mid${\sum_{k=1}}^nX_k$\mid$\geqn\in)<\infty$ for every $\in$ > 0. Under some auxiliary conditions, Sp taru (1994) extended this to the case where the $X_n$ are independent, but their distributions come from a finite set. Pruss (1996) proved Sp taru's result under weaker conditions, The purpose of this paper is to improve Pruss conditions.

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SPHERICAL FUNCTIONS ON PROJECTIVE CLASS ALGEBRAS

  • Choi, Eun-Mi
    • 대한수학회보
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    • 제43권1호
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    • pp.189-212
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    • 2006
  • Let $F^{\alpha}G$ be a twisted group algebra with basis ${{\mu}g|g\;{\in}\;G}$ and $P\;=\;{C_g|g\;{\in}\;G}$ be a partition of G. A projective class algebra associated with P is a subalgebra of $F^{\alpha}G$ generated by all class sums $\sum\limits{_{x{\in}C_g}}\;{\mu}_x$. A main object of the paper is to find interrelationships of projective class algebras in $F^{\alpha}G$ and in $F^{\alpha}H$ for H < G. And the a-spherical function will play an important role for the purpose. We find functional properties of a-spherical functions and investigate roles of $\alpha-spherical$ functions as characters of projective class algebras.

A CENTRAL LIMIT THEOREM FOR GENERAL WEIGHTED SUMS OF LPQD RANDOM VARIABLES AND ITS APPLICATION

  • Ko, Mi-Hwa;Kim, Hyun-Chull;Kim, Tae-Sung
    • 대한수학회지
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    • 제43권3호
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    • pp.529-538
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    • 2006
  • In this paper we derive the central limit theorem for ${\sum}^n_{i=l}\;a_{ni}{\xi}_{i},\;where\;\{a_{ni},\;1\;{\le}\;i\;{\le}n\}$ is a triangular array of non-negative numbers such that $sup_n{\sum}^n_{i=l}\;a^2_{ni}\;<\;{\infty},\;max_{1{\le}i{\le}n\;a_{ni}{\to}\;0\;as\;n{\to}{\infty}\;and\;{\xi}'_{i}s$ are a linearly positive quadrant dependent sequence. We also apply this result to consider a central limit theorem for a partial sum of a generalized linear process of the form $X_n\;=\;{\sum}^{\infty}_{j=-{\infty}}a_{k+j}{\xi}_{j}$.

A MEAN VALUE FUNCTION AND ITS COMPUTATIONAL FORMULA RELATED TO D. H. LEHMER'S PROBLEM

  • Wang, Tingting
    • 대한수학회보
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    • 제53권2호
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    • pp.487-494
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    • 2016
  • Let p be an odd prime and c be a fixed integer with (c, p) = 1. For each integer a with $1{\leq}a{\leq}p-1$, it is clear that there exists one and only one b with $0{\leq}b{\leq}p-1$ such that $ab{\equiv}c$ mod p. Let N(c, p) denote the number of all solutions of the congruence equation $ab{\equiv}c$ mod p for $1{\leq}a$, $b{{\leq}}p-1$ in which a and $\bar{b}$ are of opposite parity, where $\bar{b}$ is defined by the congruence equation $b{\bar{b}}{\equiv}1$ mod p. The main purpose of this paper is using the mean value theorem of Dirichlet L-functions and the properties of Gauss sums to study the computational problem of one kind mean value function related to $E(c,p)=N(c,p)-{\frac{1}{2}}{\phi}(p)$, and give its an exact computational formula.