• Kyungpook Mathematical Journal
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• 제54권2호
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• pp.333-339
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• 2014

In this paper, we describe the characterizations of omega limit sets (= ${\omega}$-limit set) on $\mathbb{R}^2$ in detail. For a local real analytic flow ${\Phi}$ by z' = f(z) on $\mathbb{R}^2$, we prove the ${\omega}$-limit set from the basin of a given attractor is in the boundary of the attractor. Using the result of Jim$\acute{e}$nez-L$\acute{o}$pez and Llibre [9], we can completely understand how both the attractors and the ${\omega}$-limit sets from the basin.

• 충청수학회지
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• 제22권1호
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• pp.73-80
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• 2009

This paper aims to study local and global structure of holomorphic flows on $\mathbb{C}^1$. At a singular point of a holomorphic flow, we locally sector the flow into parabolic or elliptic types. By the local structure of holomorphic flows, we classify all the possible types of topologies of $\omega$-limit sets.

• 대한수학회지
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• 제49권1호
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• pp.17-30
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• 2012

Let D be an arbitrary domain in $\mathbb{C}^n$, n > 1, and $M{\subset}{\partial}D$ be an open piece of the boundary. Suppose that M is connected and ${\partial}D$ is smooth real-analytic of finite type (in the sense of D'Angelo) in a neighborhood of $\bar{M}$. Let f : $D{\rightarrow}\mathbb{C}^n$ be a holomorphic correspondence such that the cluster set $cl_f$(M) is contained in a smooth closed real-algebraic hypersurface M' in $\mathbb{C}^n$ of finite type. It is shown that if f extends continuously to some open peace of M, then f extends as a holomorphic correspondence across M. As an application, we prove that any proper holomorphic correspondence from a bounded domain D in $\mathbb{C}^n$ with smooth real-analytic boundary onto a bounded domain D' in $\mathbb{C}^n$ with smooth real-algebraic boundary extends as a holomorphic correspondence to a neighborhood of $\bar{D}$.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 학술대회지
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• pp.867-871
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• 2004

In this paper, a new analytic approach for shape preserving contrast enhancement is presented. Contrast enhancement is achieved by means of segmental histogram stretching modification which preserves the given image shape, not distorting the original shape. After global stretching, the image is partitioned into several level-sets according to threshold condition. The image information of each level-set is represented as typical value based on grouped differential values. The basic property is modified into common local schemes, thereby introducing the enhanced effect through extreme discrimination between subsets. The scheme is based on stretching the histogram of subsets in which the intensity gray levels between connected pixels are approximately same In spite of histogram widening, stretched by local image information, it neither creates nor destroys the original image, thereby preserving image shape and enhancing the contrast. By designing local histogram stretching operations, we can preserve the original shape of level-sets of the image, and also enhance the global intensity. Thus it can hold the main properties of both global and local image schemes, which leads to versatile applications in the field of digital epigraphy.

• 한국지리정보학회지
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• 제4권1호
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• pp.34-46
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• 2001

GIS를 공간의사지원시스템(SDSS)으로 활용하는데 있어서 기존의 단순중첩에 의한 불린(Boolean) 분석기법은 정보의 과도한 손실과 요소간 가중치를 반영하지 못하는 문제점이 있었다. 이 연구의 목적은 토지정보시스템을 활용하면서 퍼지논리와 AHP기법을 활용하여 적지분석에 관한 사례연구를 하고자 하는 것이다. 포항시 테크노파크의 사례분석 결과에 의하면, 기존의 불린분석에 의한 적지 분석에서는 분석항목간의 가중치 차이가 반영되지 못하였고, 주거용도, 상업연구용도, 공원녹지용도의 적지로 8.0~16.1%의 지역을 분석해 내었다. 퍼지논리와 AHP분석을 병행한 경우에는 분석항목의 중요도에 따른 가중치가 적용되었고, 해당 지역의 적합도를 4등분하였을 때에 32.9~37.4%에 이르는 지역을 가장 적합한 지역으로 분석해 내었으며, 다음 차순의 지역에 관한 정보까지 제공받을 수 있었다. 이를 통해서 퍼지논리와 AHP분석을 활용한 방법이 객관적이면서 융통성있는 분석을 할 수 있는 방법임을 확인할 수 있었다.

• 한국컴퓨터정보학회논문지
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• 제7권4호
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• pp.83-88
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• 2002

데이터베이스 설계를 위해 구축된 수많은 개념적 스키마들을 재사용하기 위한 분석수단이 요구된다. 본 논문에서는 개념적 스키마를 분석하는 방법을 제시하고 참조 스키마를 추출하기 위한 스키마 분석을 실험을 하였다. 스키마 통합은 유사함 값이 0.6 이상인 경우에 적용하는 것이 바람직하다. 분석 방법을 통해 생성되는 참조 스키마는 개념을 포괄적으로 표현할 수 있고 스키마 재사용을 위한 수단이 된다. 그리고, 참조 스키마 추출에 필요한 상세한 분석자료를 구하기 위해서는 피쳐를 근거로 스키마를 분석하는 것이 효과적인 수단이 된다.

• 경영과학
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• 제18권2호
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• pp.73-85
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• 2001

Recently increasing amount of efforts has been devoted to the improvement of logistics in the marine products industry. Yet, few studios have been conducted on the development of site selection models of marine products centers. This paper Proposes a systematic assessment model for the decision making, which is composed of a set of evaluation criteria and an appropriate evaluation method. In choosing criteria we consider completeness and comprehensiveness to reach a right solution. For more flexibility of the model in the future, this study proposes two sets of criteria according to the size of planned centers. The Analytic Hierarchy Process (AHP) is adopted in this study, since the criteria incorporate both subjective factors and objective factors and the AHP is known effective in the situation. This study then illustrates the model application with plausible alternatives. Finally, a dependency problem in the decision criteria is discussed and the Analytic Network Process (ANP) is recommended, in the context, as e solution method.

• 한국경영과학회지
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• 제27권1호
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• pp.1-17
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• 2002

The objective of this paper is to develop a new priority setting algorithm that considers the cross-impact of the future technology alternatives and that satisfies the final goal of the technology management through multi-hierarchy evaluation criteria. By combining the Analytic Hierarchy Process (AHP) model, which is a well-known priority setting model, and Cross Impact Analysis (CIA) model, which is a technological forecasting method that considers cross-impact among R&D Items, we developed an Integrated Cross-Impact Hierarchical (CIH) model, which sets the priority by considering technological forecasting and technology dependency simultaneously. A step-by-step numerical example of the model developed here is presented as backup of its practicality.

• 설비공학논문집
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• 제22권7호
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• pp.468-473
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• 2010

This paper deals with approximate integral solutions to the one-dimensional model describing the charging process of stratified thermal storage tanks. Temperature is assumed to be the form of Fermi-Dirac distribution function, which can be separated to two sets of cubic polynomials for each hot and cold side of thermal boundary layers. Proposed approximate integral solutions are compared to the previous works of the approximate analytic solutions and show reasonable agreement. The approach, however, has benefits in mathematical difficulties, complicated solution form and unstable convergence of series solution founded in the previous analytic solutions. Solutions for a semi-infinite region, which have simple closed form solutions, give close agreement to those for a finite region. Thermocline thickness is obtained in closed form and shows proportional behavior to the square root of time and inverse proportional behavior to the square root of flow rate.

• Structural Engineering and Mechanics
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• 제7권4호
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• pp.361-375
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• 1999

This paper presents an analytic method of examining the out-of-plane vibration of continuous curved beam on periodical supports. The orthogonality of two distinct sets of mode shape functions is derived. The forced vibration of beam due to moving loads is examined. Two types of moving loads, which are concentrated load and uniformly distributed load, are considered. The response characteristics of beam induced by these loads are investigated as well.