• Kyungpook Mathematical Journal
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• 제51권1호
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• pp.77-85
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• 2011

In this paper, we introduce the integral operator $I_{\beta}$($p_1$, ${\ldots}$, $p_n$; ${\alpha}_1$, ${\ldots}$, ${\alpha}_n$)(z) analytic functions with positive real part. The radius of convexity of this integral operator when ${\beta}$ = 1 is determined. In particular, we get the radius of starlikeness and convexity of the analytic functions with Re {f(z)/z} > 0 and Re {f'(z)} > 0. Furthermore, we derive sufficient condition for the integral operator $I_{\beta}$($p_1$, ${\ldots}$, $p_n$; ${\alpha}_1$, ${\ldots}$, ${\alpha}_n$)(z) to be analytic and univalent in the open unit disc, which leads to univalency of the operators $\int\limits_0^z(f(t)/t)^{\alpha}$dt and $\int\limits_0^z(f'(t))^{\alpha}dt$.

• 대한수학회보
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• 제20권1호
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• pp.15-25
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• 1983

The main purpose of the present paper is to generalize the results obtained by A. Hindmarsh in [7] to the holomorphic functions with non-negative real part defined on a complete circular domain D in certain class D in the complex euclidean space $C^{n}$. As described in .cint.2, D includes the bounded symmetric domains.s.

• 전기학회논문지P
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• 제59권1호
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• pp.71-76
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• 2010

This paper is focused on implementing a real-time data acquisition system that checks power facility status by applying network based technology to Urban Transit substation power facilities and the results of its on-field tests. This system is composed of a sensor part, a measurement part, a transceiver part, a host computer, and a power source part. The system is designed to collect, save, analyze, and display the online state power facility AI (Analog Input). This system measures voltage and current from positive feeders and negative feeders where it is possible to check abnormalities of the substation‘s main power facilities. By monitoring abnormal data of the Urban Transit power facilities real-time and analyzing stored data, establishing procedures of optimized maintenance is possible.

• Structural Engineering and Mechanics
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• 제27권5호
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• pp.527-540
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• 2007

The modal controller of single-input system cannot stabilize the defective system with positive real part of repeated eigenvalues, because some of the generalized modes are uncontrollable. In order to stabilize the uncontrollable modes with positive real part of eigenvalues, the multi-input system should be introduced. This paper presents a recursive procedure for designing the feedback controller of the multi-input system with defective repeated eigenvalues. For a nearly defective system, we first transform it into a defective one, and apply the same method to manage. The proposed methods are based on the modal coordinate equations, to avoid the tedious mathematic manipulation. As an application of the presented procedure, two numerical examples are given at end of the paper.

• 대한수학회보
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• 제34권1호
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• pp.29-34
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• 1997

Let $U = {z \in C : $\mid$z$\mid$ < 1}$ be the open unit disc in the complex plane and let N be the class of all analytic functions p in U with p(0) = 1.

• 대한의용생체공학회:의공학회지
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• 제24권4호
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• pp.355-361
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• 2003

본 연구에서는 인간의 주관적 감성 변화를 실시간으로 측정할 수 있는 시스템을 개발하였다. 본 시스템은 펜 마우스와 디지타이저론 이용하여 인간의 감성 변화론 실시간으로 입력 받을 수 있는 입력 부분과. 쾌도 및 긴장도의 감성 변화즐 실시간으로 측정하고 평가할 수 있는 감성평가 및 디스플레이 부분으로 구성되어있다. 본 연구에서는 된 시스템의 유효성을 검증하기 위하여 하나의 실험을 수행하였다. 20명의 20대 남녀 피험자를 대상으로 긍정 감성과 부정 감성을 유발시킬 수 있는 사진을 각각 1장식 제시하면서 실시간 주관적 감성 평가와 함께 Galvanic Skin Response (GSR)를 실시간으로 측정하였고, 실험이 종료된 후 설문지를 이용하여 비 실시간 주관적 감성 평가를 실시하였다. 이를 통해 실시간 및 비 실시간 주관적 감성 평가, 생리 신호 평가의 결과들을 비교하였다. 상관관계 계수의 비교로부터 긍정 사진 자극으로 유발된 실시간 주관적 감성 변화는 부정 사진 자극으로 유발된 GSR 반응과, 부정 사진 자극으로 유발된 실시간 주관적 감성 변화는 부정 사진 자극으로 유발된 GSR 반응과 더 밀접한 관계가 있었다. 또한 설문지를 이용한 비 실시간 주관적 감성 평가 결과는 실시간 주관적 감성 평가의 누적된 평균 감성 값과 유사하였다. 이러한 결과로부터, 본 시스템의 가장 큰 특징은 시간에 따라 시시각각으로 변하는 인간의 주관적 감성 크기 변화를 관찰할 수 있다는 것과 자극제시 기간 동안의 평균적인 감성 평가가 가능하다는 것이다.

• 대한수학회보
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• 제55권6호
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• pp.1783-1789
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• 2018

This paper treats the class of normalized logharmonic mappings $f(z)=zh(z){\overline{g(z)}}$ in the unit disk satisfying ${\varphi}(z)=zh(z)g(z)$ is analytically typically real. Every such mapping f admits an integral representation in terms of its second dilatation function and a function of positive real part with real coefficients. The radius of starlikeness and an upper estimate for arclength are obtained. Additionally, it is shown that f maps the unit disk into a domain symmetric with respect to the real axis when its second dilatation has real coefficients.

• Kyungpook Mathematical Journal
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• 제54권3호
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• pp.365-374
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• 2014

In this paper, we introduce a new subclass of meromorphic functions defined in the punctured unit disc. We derive inclusion relationships, radius problem and some other interesting properties of this class are investigated.

• Asian Journal of Innovation and Policy
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• 제7권1호
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• pp.178-189
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• 2018

In this paper, we present a case study of a new emerging business startup involved in smart house appliances. The irreversible investment concept and real-option theory are introduced as the fundamentals of the model. By using games theory we show that the startup's actions can trigger reactions from other firms. The first part covers initial the research and development stage, while the second part covers production and commercialization. The findings of this study suggest that, given a certain amount of initial investment, an open and shared innovation may lead to hurting a firm's investment while strengthening the competitors' position in the market. However, given the sensitivity analysis, when volatility and demand grow favorably, sharing R&D investment is not a bad option for a new player to adjust its position in the market while still maintaining positive returns.

• Korean Journal of Mathematics
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• 제31권4호
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• pp.433-444
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• 2023

Given a function f analytic in open disk centred at origin of radius unity and satisfying the condition |f(z)/g(z) - 1| < 1 for a analytic function g with certain prescribed conditions in the unit disk, radii constants R are determined for the values of Rzf'(Rz)/f(Rz) to lie inside the domain enclosed by the curve |w² - 1| = 1 (lemniscate of Bernoulli). This, in turn, provides a partial solution to the conjectures and problems for determination of sharp bounds R for such functions f.