• Title/Summary/Keyword: k-covers

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Injective cover over hereditary and noetherian rings

  • Park, Sang-Won
    • Communications of the Korean Mathematical Society
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    • v.10 no.2
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    • pp.261-267
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    • 1995
  • Using the dual of a categorical definition of an injective envelope, Enochs defined an injective cover. In this paper we will show how injective covers can be used to characterize several well known classes of rings.

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Development and Commercialization of Warm Covers Using Natural Fabric (천연 소재를 이용한 보온덮개 개발 및 사업화 방안)

  • Choi, Ju-Hyun;Beak, Hyun-Kuk;Cho, Yun-Jin
    • Journal of Convergence for Information Technology
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    • v.8 no.1
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    • pp.227-233
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    • 2018
  • The purpose of this study was to develop a warm cover for greenhouse with excellent thermal insulation and to propose ways of commercialization of the product. Feathers were used as filling materials because they formed the air layer to enhance insulation. Instead of downs for clothing or other textile products, we used disposed feathers. The developed product covers the outside of the greenhouse to keep the crops warm. It has multiple layers including feathers as filling materials, padding, inside fabric, heat insulation materials and outer fabric. It has proven to improve the insulation ratio. We developed other kinds of warm covers that are applicable to the inside of the greenhouse or the small houses in the greenhouse. Also, R&D system of educational industrial complex enables us to commercialize the products and building marketing strategies for them. This technology contributes to the expansion of energy-saving facilities for farmers, and it can serve the development and spread of various products utilizing feather.

Conditions for Disjoint Path Coverability in Proper Interval Graphs (진구간 그래프의 서로소인 경로 커버에 대한 조건)

  • Park, Jung-Heum
    • Journal of KIISE:Computer Systems and Theory
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    • v.34 no.10
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    • pp.539-554
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    • 2007
  • In this Paper, we investigate conditions for proper interval graphs to have k-disjoint path covers of three types each: one-to-one, one-to-many, and many-to-many. It was proved that for $k{\geq}2$, a proper interval graph is one-to-one k-disjoint path coverable if and only if the graph is k-connected, and is one-to-many k-disjoint path coverable if and only if the graph is k+1-connected. For $k{\geq}3$, a Proper interval graph is (paired) many-to-many k-disjoint path coverable if and only if the graph is 2k-1-connected.

Unpaired Many-to-Many Disjoint Path Covers in Hypercube-Like Interconnection Networks (하이퍼큐브형 상호연결망의 비쌍형 다대다 서로소인 경로 커버)

  • Park, Jung-Heum
    • Journal of KIISE:Computer Systems and Theory
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    • v.33 no.10
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    • pp.789-796
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    • 2006
  • An unpaired many-to-many k-disjoint nth cover (k-DPC) of a graph G is a set of k disjoint paths joining k distinct sources and sinks in which each vertex of G is covered by a path. Here, a source can be freely matched to a sink. In this paper, we investigate unpaired many-to-many DPC's in a subclass of hpercube-like interconnection networks, called restricted HL-graphs, and show that every n-dimensional restricted HL-graph, $(m{\geq}3)$, with f or less faulty elements (vertices and/or edges) has an unpaired many-to-many k-DPC for any $f{\geq}0\;and\;k{\geq}1\;with\;f+k{\leq}m-2$.

LINE GRAPHS OF COVERING GRAPHS ARE COVERING GRAPHS

  • Dan Archdeacon;Lee, Jaeun;Sohn, Moo-Young
    • Bulletin of the Korean Mathematical Society
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    • v.37 no.3
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    • pp.487-491
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    • 2000
  • Let G be a covering graph of G. We show that the line graph of G covers the line graph of G. Moreover, if the first covering is regular, then the line-graph covering is regular.

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Many-to-Many Disjoint Path Covers in Double Loop Networks (이중 루프 네트워크의 다대다 서로소인 경로 커버)

  • Park Jung-Heum
    • Journal of KIISE:Computer Systems and Theory
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    • v.32 no.8
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    • pp.426-431
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    • 2005
  • A many-to-many k-disjoint path cover (k-DPC) of a graph G is a set of k disjoint paths joining k distinct source-sink pairs in which each vertex of G is covered by a path. In this paper, we investigate many-to-many 2-DPC in a double loop network G(mn;1,m), and show that every nonbipartite G(mn;1,m), $m{\geq}3$, has 2-DPC joining any two source-sink pairs of vertices and that every bipartite G(mn;1,m) has 2-DPC joining any two source-sink pairs of black-white vertices and joining any Pairs of black-black and white-white vertices. G(mn;l,m) is bipartite if and only if n is odd and n is even.

STRUCTURE OF THE FLAT COVERS OF ARTINIAN MODULES

  • Payrovi, S.H.
    • Journal of the Korean Mathematical Society
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    • v.39 no.4
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    • pp.611-620
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    • 2002
  • The aim of the Paper is to Obtain information about the flat covers and minimal flat resolutions of Artinian modules over a Noetherian ring. Let R be a commutative Noetherian ring and let A be an Artinian R-module. We prove that the flat cover of a is of the form $\prod_{p\epsilonAtt_R(A)}T-p$, where $Tp$ is the completion of a free R$_{p}$-module. Also, we construct a minimal flat resolution for R/xR-module 0: $_AX$ from a given minimal flat resolution of A, when n is a non-unit and non-zero divisor of R such that A = $\chiA$. This result leads to a description of the structure of a minimal flat resolution for ${H^n}_{\underline{m}}(R)$, nth local cohomology module of R with respect to the ideal $\underline{m}$, over a local Cohen-Macaulay ring (R, $\underline{m}$) of dimension n.

Review And Challenges In Speech Recognition (ICCAS 2005)

  • Ahmed, M.Masroor;Ahmed, Abdul Manan Bin
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.1705-1709
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    • 2005
  • This paper covers review and challenges in the area of speech recognition by taking into account different classes of recognition mode. The recognition mode can be either speaker independent or speaker dependant. Size of the vocabulary and the input mode are two crucial factors for a speech recognizer. The input mode refers to continuous or isolated speech recognition system and the vocabulary size can be small less than hundred words or large less than few thousands words. This varies according to system design and objectives.[2]. The organization of the paper is: first it covers various fundamental methods of speech recognition, then it takes into account various deficiencies in the existing systems and finally it discloses the various probable application areas.

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Applying a Two-Stage Option Games Method to Investment Decisions of Business Startups: Case Study of a Smart House Startup in Indonesia

  • Wardani, Ida Sri;Fujiwara, Takao
    • Asian Journal of Innovation and Policy
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    • v.7 no.1
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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.