• Title/Summary/Keyword: covers

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WALLMAN COVERS AND QUASI-F COVERS

  • Kim, Chang Il;Shin, Chang Hyeob
    • The Pure and Applied Mathematics
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    • v.20 no.2
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    • pp.103-108
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    • 2013
  • Observing that for any space X, there is a Wallman sublattice $\mathfrak{A}_X$ and that QFX is homeomorphic to a subspace $X_q$ of the Wallman cover $\mathfrak{L}(\mathfrak{A}_X)$ of $\mathfrak{A}_X$, we show that ${\beta}QFX$ and $\mathfrak{L}(\mathfrak{A}_X)$ are homeomorphic.

DOUBLE COVERS OF PLANE CURVES OF DEGREE SIX WITH ALMOST TOTAL FLEXES

  • Kim, Seon Jeong;Komeda, Jiryo
    • Bulletin of the Korean Mathematical Society
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    • v.56 no.5
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    • pp.1159-1186
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    • 2019
  • In this paper, we study plane curves of degree 6 with points whose multiplicities of the tangents are 5. We determine all the Weierstrass semigroups of ramification points on double covers of the plane curves when the genera of the covering curves are greater than 29 and the ramification points are on the points with multiplicity 5 of the tangent.

Finding Approximate Covers of Strings (문자열의 근사커버 찾기)

  • Sim, Jeong-Seop;Park, Kun-Soo;Kim, Sung-Ryul;Lee, Jee-Soo
    • Journal of KIISE:Computer Systems and Theory
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    • v.29 no.1
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    • pp.16-21
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    • 2002
  • Repetitive strings have been studied in such diverse fields as molecular biology data compression etc. Some important regularities that have been studied are perods, covers seeds and squares. A natural extension of the repetition problems is to allow errors. Among the four notions above aproximate squares and approximate periodes have been studied. In this paper, we introduce the notion of approximate covers which is an approximate version of covers. Given two strings P(|P|=m) and T(|T|=n) we propose and algorithm with finds the minimum distance t such that P is a t-approximate cover of T. The algorithm take O(m,n) time for the edit distance and $O(mn^2)$ time of finding a string which is an approximate cover of T is minimum distance is NP-complete.

Research and Development for the Recovery of Uranium and Vanadium from Korean Black Shale Ore (국내(國內) 흑색(黑色) 점판암으로부터 우라늄 및 바나듐 회수(回收)의 연구개발(硏究開發))

  • Kim, Joon Soo
    • Resources Recycling
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    • v.22 no.1
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    • pp.3-10
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    • 2013
  • This general paper covers three parts of the uranium research and development. Part one covers scope of research and development of uranium ore and future prospect, supply and demand of uranium in the world market, deposit, grade and properties of Korean uranium ore and the second part covers status of previous study and supply target for yellow cake, technology of leaching, separation and preparation, procedure of the recovery of U / V from Korean black shale ore. Final part concludes the summary of the present discussion.

Nonlinear Stress Analysis of Dust Covers for Ball Joint of Automotive Steering System (자동차 조향장치의 볼 조인트 더스트 커버의 비선형 응력해석)

  • Kim, Ji Ho;Lee, Boo Youn
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.37 no.10
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    • pp.1297-1303
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    • 2013
  • A nonlinear finite element analysis is performed to evaluate the sealing capability and stress of dust covers for the ball joint of an automotive steering system. The analysis is performed for two types of dust covers: wrinkle type and pot type. The assembly condition and operation condition are analyzed, and the maximum stress and contact normal stress at the ribs are evaluated. It is confirmed that the sealing capability of both types is fairly good, but the wrinkle type is better than the pot type in terms of the maximum stress.

Comparative Analysis of the Multispectral Vegetation Indices and the Radar Vegetation Index

  • Kim, Yong-Hyun;Oh, Jae-Hong;Kim, Yong-Il
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.32 no.6
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    • pp.607-615
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    • 2014
  • RVI (Radar Vegetation Index) has shown some promise in the vegetation fields, but its relationship with MVI (Multispectral Vegetation Index) is not known in the context of various land covers. Presented herein is a comparative analysis of the MVI values derived from the LANDSAT-8 and RVI values originating from the RADARSAT-2 quad-polarimetric SAR (Synthetic Aperture Radar) data. Among the various multispectral vegetation indices, NDVI (Normalized Difference Vegetation Index) and SAVI (Soil Adjusted Vegetation Index) were used for comparison with RVI. Four land covers (urban, forest, water, and paddy field) were compared, and the patterns were investigated. The experiment results demonstrated that the RVI patterns of the four land covers are very similar to those of NDVI and SAVI. Thus, during bad weather conditions and at night, the RVI data could serve as an alternative to the MVI data in various application fields.

Paired Many-to-Many Disjoint Path Covers in Recursive Circulants and Tori (재귀원형군과 토러스에서 쌍형 다대다 서로소인 경로 커버)

  • Kim, Eu-Sang;Park, Jung-Heum
    • Journal of KIISE:Computer Systems and Theory
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    • v.36 no.1
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    • pp.40-51
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    • 2009
  • A paired many-to-many k-disjoint path cover (paired 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 disjoint path covers in recursive circulants G($cd^m$,d) with $d{\geq}3$ and tori, and show that provided the number of faulty elements (vertices and/or edges) is f or less, every nonbipartite recursive circulant and torus of degree $\delta$ has a paired k-DPC for any f and $k{\geq}1$ with $f+2k{\leq}{\delta}-1$.

A Study on the Reinforcement Method of the Door Lock Box Frame for Easy Field Processing Assembly in Steel Door (강철재도어에서 현장가공조립이 용이한 도어락상자틀 보강방법에 대한 연구)

  • Iim, Bo-Hyuk;Lee, Joo-Won;Cho, Seong-Gwon;Lee, Hae-Yeol
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2023.05a
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    • pp.133-134
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    • 2023
  • In general, all buildings are equipped with various types of handles for opening and closing the door, and unlike wooden doors, steel doors such as fire doors are equipped with a box-shaped door lock box frame surrounding the outside of the door lock to protect the door lock, which is called a cylinder protection cover. These cylinder protection covers have various types and types of fastening structures, and the cylinder protection covers on the market are molded in factories and standardized according to the size and shape of the door lock, requiring various types of cylinder protection covers. Accordingly, a variable cylinder protection cover with a simple prefabricated structure that can fundamentally solve these problems can be used as one cylinder protection cover regardless of the type, shape, and size of the door lock.

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Estimation of Nutrient Contribution of Perennial Ground Covers in Organic Orchards and Growth Characteristics (유기과수원에 자생하는 여러해살이 초종 특성과 양분공급 추정)

  • Lim, Kyeong-Ho;Choi, Hyun-Sug;Song, Jang-Hoon;Cho, Young-Sik;Cho, Kwang-Sik;Ma, Kyeong-Bok;Won, Kyeong-Ho;Jung, Seok-Kyu
    • Journal of Bio-Environment Control
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    • v.21 no.3
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    • pp.286-293
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    • 2012
  • This study was initiated to find out the suitable perennial ground covers naturally grown in thirteen organic orchards in Chonnam Province as a organic nutrient source for maintaining annual fruit tree growth. The ground covers were observed in April, June, and August in the orchards. Agropyron tsukusinense and Panicum virgatum observed in April and June, respectively, produced the highest dry weight, which increased amounts of N, $P_2O_5$, and $K_2O$, mineralizing from the residue in the ground covers. The occurrence of perennial ground covers in August decreased compared to April and June. Amount of residue in mowed Agropyron tsukusinense and Panicum virgatum satisfied nutrient demand (N; 20 kg/10a, $P_2O_5$; 11 kg/10a, and $K_2O$; 19 kg/10a) to achieve the annual growth of twenty-year old fruit tree.

Comforts Evaluation of Car Seat Clothing (자동차 시트 표피재의 감성평가)

  • Kim, Joo-Yong;Lee, Chae-Jung;Kim, An-Na;Lee, Chang-Hwan
    • Science of Emotion and Sensibility
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    • v.12 no.1
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    • pp.77-86
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    • 2009
  • A comfort evaluation of car seat clothing has been proposed for high comforts interior seat clothing. Car seat covers have received wide spread attention due to their man-machine interface working. And then, it will be necessary for measurements on delicate basic mechanical-properties, which closely relate with human touch feeling of its materials. In this research, we have utilized $KES-FB^{(R)}$(Kawabata Evaluation System) series, $^ST300{(R)}$ analogue softness tester and friction tester for measurement a physical properties. In order to consider both kansei and physical properties on interior seat covers, we firstly have established subjective words of judgement for the seat covers. Secondly, related them to the objective measurement of physical properties. Each kansei-language has clearly defined as 'Softness', 'Elasticity', 'Volume' and 'Stickiness' for the adjectives of leather car seat covers. These technical terms have correlated to physical properties in other words, h (mm), bending moment ($gf^*$cm/cm), To-Tm (mm) and ${\mu}$. At this time, fuzzy logic has utilized to predict the value of kansei language through physical values. On the basis of this result, finally it is possible to predict quality index of car seat covers using neural networks technique. In short, we develop a quality evaluation system of car seat clothing combining four physical quantities with kansei engineering.

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