• 제목/요약/키워드: extension theory

검색결과 411건 처리시간 0.036초

농촌지도사업에서 혁신전파이론의 이론적 함의 (Challenges of Diffusion of Innovation Theory on Agricultural Extension and Its Implications)

  • 박덕병;이민수
    • 농촌지도와개발
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    • 제13권1호
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    • pp.1-14
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    • 2006
  • The diffusion of innovation theory provided the basis for a model of agricultural development that the extension service continues to use today. This study aims to examine the history, influence, and impacts of innovation diffusion theory on the extension service. It reviews some of the major developments in the literature related to the theory, examines its criticisms, and discusses the implications for extension. As such, innovators are younger, more cosmopolitan, have higher incomes than later adopters, and have the largest operations of all adopter categories. There are two critiques on diffusion of innovation theory in which are the method and inequity recurring from diffusion.

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COHOMOLOGY GROUPS OF RADICAL EXTENSIONS

  • Choi, Eun-Mi
    • 대한수학회지
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    • 제44권1호
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    • pp.151-167
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    • 2007
  • If k is a subfield of $\mathbb{Q}(\varepsilon_m)$ then the cohomology group $H^2(k(\varepsilon_n)/k)$ is isomorphic to $H^2(k(\varepsilon_{n'})/k)$ with gcd(m, n') = 1. This enables us to reduce a cyclotomic k-algebra over $k(\varepsilon_n)$ to the one over $k(\varepsilon_{n'})$. A radical extension in projective Schur algebra theory is regarded as an analog of cyclotomic extension in Schur algebra theory. We will study a reduction of cohomology group of radical extension and show that a Galois cohomology group of a radical extension is isomorphic to that of a certain subextension of radical extension. We then draw a cohomological characterization of radical group.

3상 불평형 전압 시스템에서의 전압원 active power filter (The VSI active power filter in 3-phase unsymmetrical voltage system)

  • 김갑동;이완수;김민태;오성업;주형준;이진;성세진
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 1999년도 전력전자학술대회 논문집
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    • pp.667-670
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    • 1999
  • An active power filter is used to eliminate harmonic currents. This paper applied the extension pq theory to harmonic currents compensation. An active power filter based on extension pq theory is more effective than pq theory in 3-phase unsymmetrical voltage system. When extension pq theory is used, the result of simulation present source current is not distorted. Pulse-width modulation method is CRPWM(Current-Regulated PWM).

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A surface extension method using several functions

  • 김회섭
    • 한국전산응용수학회:학술대회논문집
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    • 한국전산응용수학회 2003년도 KSCAM 학술발표회 프로그램 및 초록집
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    • pp.3.2-3
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    • 2003
  • We propose a method of surface extension method using several functions. Interpolation theory is well developed in curve and surface. But extrapolation theory is not well developed because it is not unique outside the useful domain. It requires continuous, first derivative, second derivative continuous extension for matching in NC(Numerical Control) machine. In the past, we generate data outside the useful area and refit those data using least squares method. this has some problems which have some errors within the useful area. We keep the useful area and extend the unuseful area by a function

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Grouting effects evaluation of water-rich faults and its engineering application in Qingdao Jiaozhou Bay Subsea Tunnel, China

  • Zhang, Jian;Li, Shucai;Li, Liping;Zhang, Qianqing;Xu, Zhenhao;Wu, Jing;He, Peng
    • Geomechanics and Engineering
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    • 제12권1호
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    • pp.35-52
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    • 2017
  • In order to evaluate the grouting effects of water-rich fault in tunnels systematically, a feasible and scientific method is introduced based on the extension theory. First, eight main influencing factors are chosen as evaluation indexes by analyzing the changes of permeability, mechanical properties and deformation of surrounding rocks. The model of evaluating grouting effects based on the extension theory is established following this. According to four quality grades of grouting effects, normalization of evaluation indexes is carried out, aiming to meet the requirement of extension theory on data format. The index weight is allocated by adopting the entropy method. Finally, the model is applied to the grouting effects evaluation in water-rich fault F4-4 of Qingdao Jiaozhou Bay Subsea Tunnel, China. The evaluation results are in good agreement with the test results on the site, which shows that the evaluation model is feasible in this field, providing a powerful tool for systematically evaluating the grouting effects of water-rich fault in tunnels.

모서리값 확장 그래프를 사용한 함수구성에 관한연구 (A Study on the Constructing the Function using Extension Edge Valued Graph)

  • 박춘명
    • 한국정보통신학회논문지
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    • 제17권4호
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    • pp.863-868
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    • 2013
  • 본 논문에서는 최근의 디지털논리시스템의 함수구성시에 도입되고 있는 그래프이론에 바탕을 둔 새로운 형태의 데이터구조 형태인 모서리값 확장 그래프를 추출하는 알고리즘을 제안하였다. 이를 위해 수학적 배경으로는 리터럴 함수와 리드 뮬러 확장에 대해 논의하였으며, 본 논문의 근간인 모서리 확장 그래프의 도출에 대해 논의하였다. 또한, 모서리 확장 그래프로부터 임의의 m치 n변수의 축약된 함수구성을 도출하는 알고리즘을 제안하였으며 이를 예에 적용하여 그 타당성을 보였다. 제안된 알고리즘의 규칙성을 고려하여 동일부분을 모듈화함으로써 일반성을 가짐을 보였다.

소비자 성향과 브랜드 컨셉에 따른 브랜드확장평가에 관한 연구 (Study on Brand Extension Evaluation of Consumer Preference and Brand Concept : Focused on Similarity)

  • 임채숙
    • 한국산학기술학회논문지
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    • 제16권2호
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    • pp.1054-1063
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    • 2015
  • 본 연구는 소비자 성향과 브랜드 컨셉이 확장 브랜드 평가에 미치는 주 효과를 살펴봄으로써, 효과적이고 전략적인 브랜드 확장 전량의 가능성을 실증적으로 분석해 보고자 한다. 본 연구의 실증적 검증을 위하여, 브랜드 확장 유형(유사/비유사)${\times}$브랜드 컨셉(상징적/기능적)${\times}$암묵적 소비자 성향(가변론적/고정론적)의 실험설계를 하였으며, 연구결과는 다음과 같다. 첫째, 모 브랜드와 확장제품 간의 유사성에 따른 주 효과가 통계적으로 유의하게 나타났다. 둘째, 상징적 브랜드인 경우, 소비자의 확장 브랜드에 대한 태도가 더 긍정적인 것으로 나타났고, 확장제품의 유사성과 브랜드 컨셉의 유형 간의 상호작용 효과가 통계적으로 유의하게 나타났다. 셋째, 개인의 암묵적 사고 유형과 브랜드 확장 유사성 간의 상호작용 효과가 통계적으로 유의하게 나타났지만, 가변론자가 고정론자에 비해 브랜드 확장에 대한 태도가 긍정적으로 나타날 것이라는 가설은 통계적으로 유의하지 못 한 것으로 나타났다. 본 연구는 비 유사한 제품군으로의 브랜드 확장의 효과를 높일 수 있는 실무적인 시사점을 제시할 수 있을 것으로 기대된다.

ON THE THEORY OF SELECTIONS

  • LEE, SEUNG WOO
    • 호남수학학술지
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    • 제19권1호
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    • pp.125-130
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    • 1997
  • In this paper, we give a characterization of collectionwise normality using continuous functions. More precisely, we give a new and short proof of the Dowker's theorem using selection theory that a $T_1$ space X is collectionwise normal if every continuous mapping of every closed subset F of X into a Banach space can be continuously extended over X. This is also a generalization of Tietze's extension theorem.

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APPLICATIONS OF THE REPRODUCING KERNEL THEORY TO INVERSE PROBLEMS

  • Saitoh, Saburou
    • 대한수학회논문집
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    • 제16권3호
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    • pp.371-383
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    • 2001
  • In this survey article, we shall introduce the applications of the theory of reproducing kernels to inverse problems. At the same time, we shall present some operator versions of our fundamental general theory for linear transforms in the framework of Hilbert spaces.

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FIXED POINT THEOREMS OF EXTENSION AND MODIFIED EXTENSION α-F-CONTRACTION ON COMPLETE METRIC SPACE

  • Saeed A. A. Al-Salehi;V. C. Borkar
    • Nonlinear Functional Analysis and Applications
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    • 제29권2호
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    • pp.461-475
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    • 2024
  • The concept of an extension α-F-contraction and it's modified counterpart represents an advancement in the theory of metric space contractions. Through our study of the contraction principles and it's relationship to extension and modified extension, we found different conditions somewhat lengthy. In our paper, we create a development of the conditions for the extension of α-F-contraction and a modified α-F-contraction by reducing the conditions and make them easier. Our propose conditions are notably simple and effective. They serve as the foundation for proving theorems and solving examples that belong to our study. Moreover, they have remarkable significance in the condition of mathematical analysis and problem-solving. Thus, we find that these new conditions that we mention in the definitions achieve what is require and through them, we choose λ = 1 and we choose λ ∈ (0, 1) to clarify our ideas.