• Title/Summary/Keyword: Positive Function

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CHARACTERIZATIONS OF THE GAMMA DISTRIBUTION BY INDEPENDENCE PROPERTY OF RANDOM VARIABLES

  • Jin, Hyun-Woo;Lee, Min-Young
    • Journal of the Chungcheong Mathematical Society
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    • v.27 no.2
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    • pp.157-163
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    • 2014
  • Let {$X_i$, $1{\leq}i{\leq}n$} be a sequence of i.i.d. sequence of positive random variables with common absolutely continuous cumulative distribution function F(x) and probability density function f(x) and $E(X^2)$ < ${\infty}$. The random variables X + Y and $\frac{(X-Y)^2}{(X+Y)^2}$ are independent if and only if X and Y have gamma distributions. In addition, the random variables $S_n$ and $\frac{\sum_{i=1}^{m}(X_i)^2}{(S_n)^2}$ with $S_n=\sum_{i=1}^{n}X_i$ are independent for $1{\leq}m$ < n if and only if $X_i$ has gamma distribution for $i=1,{\cdots},n$.

FEW RESULTS IN CONNECTION WITH SUM AND PRODUCT THEOREMS OF RELATIVE (p, q)-𝜑 ORDER, RELATIVE (p, q)-𝜑 TYPE AND RELATIVE (p, q)-𝜑 WEAK TYPE OF MEROMORPHIC FUNCTIONS WITH RESPECT TO ENTIRE FUNCTIONS

  • Biswas, Tanmay
    • The Pure and Applied Mathematics
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    • v.26 no.4
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    • pp.315-353
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    • 2019
  • Orders and types of entire and meromorphic functions have been actively investigated by many authors. In the present paper, we aim at investigating some basic properties in connection with sum and product of relative (p, q)-𝜑 order, relative (p, q)-𝜑 type, and relative (p, q)-𝜑 weak type of meromorphic functions with respect to entire functions where p, q are any two positive integers and 𝜑 : [0, +∞) → (0, +∞) is a non-decreasing unbounded function.

A PROXIMAL POINT-TYPE ALGORITHM FOR PSEUDOMONOTONE EQUILIBRIUM PROBLEMS

  • Kim, Jong-Kyu;Anh, Pham Ngoc;Hyun, Ho-Geun
    • Bulletin of the Korean Mathematical Society
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    • v.49 no.4
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    • pp.749-759
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    • 2012
  • A globally convergent algorithm for solving equilibrium problems is proposed. The algorithm is based on a proximal point algorithm (shortly (PPA)) with a positive definite matrix M which is not necessarily symmetric. The proximal function in existing (PPA) usually is the gradient of a quadratic function, namely, ${\nabla}({\parallel}x{\parallel}^2_M)$. This leads to a proximal point-type algorithm. We first solve pseudomonotone equilibrium problems without Lipschitzian assumption and prove the convergence of algorithms. Next, we couple this technique with the Banach contraction method for multivalued variational inequalities. Finally some computational results are given.

Some properties of the set of schwarzians of conformal functions

  • Jong Su An;Tai Sung Song
    • Communications of the Korean Mathematical Society
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    • v.11 no.3
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    • pp.665-672
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    • 1996
  • Let U denote the set of all Schwarzian derivatives $S_f$ of conformal function f in the unit disk D. We show that if $S_f$ is a local extreme point of U, then f cannot omit an open set. We also show that if $S_f \in U$ is an extreme point of the closed convex hull $\bar{co}U$ of U, then f cannot omit a set of positive area. The proof of this uses Nguyen's theorem.

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Effects of a Group Exercise Program for the Upper Extremities on Sensory and Motor Function and Activities of Daily Living in Chronic Stroke Patients: A Case Series

  • Ko, Myung-Sook;Jeon, Yong-Jin
    • Physical Therapy Korea
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    • v.22 no.2
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    • pp.59-69
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    • 2015
  • The purpose of this study was to identify the effects of an upper extremities group exercise program based on motor learning in chronic stroke patients and to assess improvements in upper sensory motor function and activities of daily living (ADL). Five chronic stroke patients participated for the duration of 25 weeks. On the assessment of motor and process skills, there was a statistically significant improvement in motor area functioning in 4 of the subjects. In process area functioning, there was a statistically significant change in 3 of the subjects. Therefore, further studies are needed to assess sensorimotor area and ADL changes in chronic stroke patients to reduce medical cost and assess for positive psychological changes.

Protective-stabilizing function of parenting process and school process in the Relationship Between Adolescents' academic achievement and self-evaluation (청소년의 학업성취와 자아평가의 관계에서 부모과정과 학교과정의 보호적-안정화 기능)

  • Jung, Hyun-Ju;Lee, Ju-Rhee
    • Korean Journal of Human Ecology
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    • v.18 no.3
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    • pp.609-618
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    • 2009
  • The study examined the effects of parenting process(supportive and involving mother-adolescent relationship, father-adolescent relationship) and school process(teachers' support, school life satisfaction) on adolescents' academic achievement and self-evaluation. Participants were 1787 middle school students (902 boys, 885 girls) in KEEP(Korean Education and Employment Panel). Structural equation modeling indicated that parenting and school process influenced adolescents' self-evaluation through adolescents' academic achievement. Also, the analysis with One Way ANOVA revealed that positive school (parenting) processes can serve a protective-stabilizing function when parenting(school) processes are negative.

ON THE EXISTENCE OF EQUILIBRIUM PRICE

  • Kim, Won-Kyu;Rim, Dong-Il
    • Journal of the Korean Mathematical Society
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    • v.33 no.1
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    • pp.25-29
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    • 1996
  • The Debreu-Gale-Nikaido theorem [2] is a potential tool to prove the existence of a market equilibrium price. Walras' law is of a quantitative nature (i.e. it measures the value of the total excess demand), and it is interesting to note that the existence result holds true under some qualitative assumptions. In fact, the Debreu-Gale-Nikaido theorem states that the continuity of the excess demand function and Walras' law has the following implication : For some price and corresponding value of the excess demand function, it is not possible to respond with a new price system such that the value at the new price of every element in the value of the demand function associated with the old price system is strictly positive.

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A new torque sharing function method for torque control of a switched reluctance motor (토크 공유 함수법을 이용한 새로운 방식의 스위치드 리럭턴스 모터의 토크 제어)

  • 최창환;이대옥;박기환
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.262-262
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    • 2000
  • This paper presents a new torque sharing function method that extends the definition region of the conventional TSF to both the positive and negative torque production regions. By using this definition, all kinds of the control inputs that consider switching on/off angle control as well as the current profiling can be described. A parametrized representation of the current profiles is proposed by using a series of B-spline functions, which reduces memory requirement and enables additional controllers. Optimal determination of the TSFs are also investigated for various control objectives. Moreover, the comparison study of each objective is presented. Since this method generalizes all of the possible control input, the current and torque profiles obtained from the optimization are the most suitable control input that satisfy the objectives.

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Torque Control of a Switched Reluctance Motor for the Precision Position Control of a Tank Gun (전차 포신의 정밀 위치 제어를 위한 스위치드 리럭턴스 모터의 토크 제어)

  • 최창환;김용대;이대옥;박기환
    • Journal of the Korea Institute of Military Science and Technology
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    • v.3 no.2
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    • pp.42-52
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    • 2000
  • A torque control method of a switched reluctance motor for the position control of a tank gun is presented. One of the widely used torque control scheme, torque sharing function method, is investigated and a new torque sharing function method is proposed that extends the definition region of the conventional TSF to both the positive and negative torque production regions. By using this definition, all kinds of the control inputs that consider switching on/off angle control as well as the current profiling can be described. A parametrized representation of the current profiles is proposed by using a series of B-spline functions, which reduces memory requirement and enables additional controllers. Optimal determination of the TSFs are also investigated for various control objectives. Moreover, the comparison study of each objective is presented. Since this method generalizes all of the possible control input, the current and torque profiles obtained from the optimization are the most suitable control input that satisfy the objectives.

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Analysis of the Parameter Convergence Rate for an Adaptive Identifier (적응추정자에 대한 파라메터 수렴속도의 해석)

  • Kim, Sung-Duck
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.38 no.2
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    • pp.127-136
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    • 1989
  • This paper describes the parameter convergence properties of an adaptive system to identify a single-input single-output plant model. It is demonstrated that, by using power spectrum analysis, the persistency of excitation (PE) condition in order to guarantee the exponential stability of the adaptive control system can be transformed into the positive definite behavior for the auto-correlation function matrix of adaptive signal. The existence of parameter nominal values can be analyzed by this condition and the convergence rates of parameter are determined by examining the auto-correlation function. We may use the sufficient richness (SR) of input spectrum instead of the PE condition to analyze the parameter boundedness. It can be shown that the eigen values of the auto-correlation function are always related with adaptive gain, input amplitude and positions or numbers of input spectra. In each case, the variation of parameter convergence rate can be also verified.

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