• Title/Summary/Keyword: extension theory

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

  • Park, Duk-Byeong;Lee, Min-Soo
    • Journal of Agricultural Extension & Community Development
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    • v.13 no.1
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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
    • Journal of the Korean Mathematical Society
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    • v.44 no.1
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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.

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

  • Kim, Gap-Dong;Lee, Wan-Soo;Kim, Min-Tae;Oh, Sung-Up;Joo, Hyung-Joon;Lee, Jin;Sung, Se-Jin
    • Proceedings of the KIPE Conference
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    • 1999.07a
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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
    • Proceedings of the Korean Society of Computational and Applied Mathematics Conference
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    • 2003.09a
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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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    • v.12 no.1
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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.

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

  • Park, Chun-Myoung
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.4
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    • pp.863-868
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    • 2013
  • In recently years, many digital logic systems based on graph theory are analyzed and synthesized. This paper presented a method of constructing the function using edge valued extension graph which is based on graph theory. The graph is applied to a new data structure. from binary graph which is recently used in constructing the digital logic systems based on the graph theory. We discuss the mathematical background of literal and reed-muller expansion, and we discuss the edge valued extension graph which is the key of this paper. Also, we propose the algorithms which is the function derivation based on the proposed edge valued extension graph. That is the function minimization method of the n-variables m-valued functions and showed that the algorithm had the regularity with module by which the same blocks were made concerning about the schematic property of the proposed algorithm.

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

  • Lim, Chae-Suk
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.2
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    • pp.1054-1063
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    • 2015
  • This study is to verify the effect of similarity of expanded-product, brand concepts of parent-brands and implicit theory of customers on the brand-extension evaluation, in order to reduce the risk of brand extension. First, this research documents how the similarity between the parent-brands and expanded-products affect brand-extension evaluations as a main effect variable. Second, this study examines the moderating effect of the brand concepts of parent-brands on the brand-extension evaluation. Third, this research documents how implicit theories regarding personality affect consumer evaluations about the brand-extension. The study assumes and tests that consumers in the group of incremental theorists are more accepting of brand-extensions than consumers in the group of entity theorists. The result figures out the implicit theory customers has some moderating effect on the evaluations, yet the direction of the effects is contrary to expectations.

ON THE THEORY OF SELECTIONS

  • LEE, SEUNG WOO
    • Honam Mathematical Journal
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    • v.19 no.1
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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
    • Communications of the Korean Mathematical Society
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    • v.16 no.3
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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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