• Title/Summary/Keyword: 다양성지수

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Development of 400kV Oil-filled power cable system with $KPK^{(R)}$ (400kV 반합성지 전력케이블 시스템 개발)

  • Kim, J.S.;Son, S.H.;Youn, B.K.;Lee, I.H.;Cho, H.S.;Jeong, B.L.
    • Proceedings of the KIEE Conference
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    • 2007.11a
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    • pp.186-187
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    • 2007
  • 반합성지 절연 전력케이블 시스템은 유전체 손실을 줄이고 절연두께 저감할 수 있으며 경제성면에서도 유리하다는 장점 때문에 많은 사용검토가 이루어져 왔다. 본 논문은 최근 LS전선이 국내 최초로 개발한 400kV급 초고압 반합성지 전력케이블의 반합성지 설계, 케이블 및 접속함 개발, 그리고 인증 Type Test 및 장시간 실증시험등 주요 개발과정을 기술하였다. OF 전력케이블의 오랜 경험과 다양한 연구결과를 바탕으로 반합성지 전력케이블 시스템을 단기 내에 개발하여 전력 케이블 및 접속함에 대하여 국제공인기관인 KEMA로부터 IEC 60141-1에 따른 인증서를 획득하였고, 장시간 실증시험에 성공적으로 완료함으로써 반합성지 절연 전력케이블 시스템 전체의 신뢰성을 확인할 수 있었다.

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Reliability Analysis Considering Modeling Uncertainty (모델링불확실성을 고려한 신뢰성 해석)

  • Kim, Jeong-Jung
    • Computational Structural Engineering
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    • v.28 no.3
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    • pp.13-17
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    • 2015
  • 본 기사에서는 모델링불확실성(modeling uncertainty)에 따른 신뢰성 해석결과의 가변성(variability)을 가능성 분포함수(possibility distribution function)를 구성하여 해결하는 방법을 AISC(1998), AIJ(1985), CSA(1994)에서 제안된 3개의 최대 D/t 계산식을 예로 들어 소개하였다. 확신정도가 측정된 신뢰성지수 들을 얻을 수 있으며, 확신정도를 고려한 신뢰성지수의 결정이 가능하게 된다. 다양한 형태의 불확실성에 대하여 그 형태에 맞는 적합한 불확실성 모델링을 사용하는 것도 중요하지만, 확률적 표현에 익숙한 우리의 인지구조를 고려하여 기존의 신뢰성 해석에 어떻게 다양한 불확실성 모델링 방법을 접목시킬 것인지에 대한 연구도 중요할 것이다.

Reliability-Based Load and Resistance Factor Design (신뢰성 이론에 의한 하중 및 저항계수 설계)

  • Son, Seung Yo;Lee, Jong Heon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.7 no.4
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    • pp.1-12
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    • 1987
  • The Advanced First Order Second Moment(AFOSM) method is commonly used to determine partial safety factors in the development of probability based LRFD code. However, design format using load and resistance factors based on this method may result in different reliability levels from specified ones. Reliability-Conditioned(RC) method recently proposed by Ayyub et al. gives partial safety factors which do not affect the target reliability level as specified. However, this method has some numerical difficulties and the procedure is not consistent. The proposed RC/AFOSM combined method has not only numerical consistency, but also results in almost constant partial safety factors with respect to various design conditions, and the resulting reliability levels are very close to specified ones.

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A Historical Geography of the Castles in the Sacheon Bay Region (사천만 연안에 축성된 성(城)의 유형과 기능에 관한 역사지리적 연구)

  • Lee, Jeon
    • Journal of the Korean association of regional geographers
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    • v.6 no.1
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    • pp.51-68
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    • 2000
  • The Sacheon bay region functioned as a strategic place as the bay provided a major sea-route leading to the Kyungnam province. So it is no wonder that a number of castles and walls were located in such an outlying post of strategic importance. In the bay region there are found Sacheon, Gonyang and Seonghwangdang town castles, Yeegu, Seongbangri, Shinbyukdong, Duckgockri, Baekcheondong and Gaksan miltary castles, Seonjinri and Sadung Japanese castles, Kumseonri and Wueolseongri mud walls, Gaksan, Anjeom, Chimzi and Usan beacon-post walls, and Tongyang, Gasan and Jangam warehouse walls(사천읍성, 곤양읍성, 성황당산성, 이구산성, 성방리산성, 신벽동산성, 덕곡리산성, 백천동산성, 각산산성, 사등산성지, 선진리성, 금성리 토성, 월성리 토성지, 각산봉수대성, 안점봉수대성, 침지봉수대성지, 우산봉수대성, 통양창성지, 가산창성지, 장암창성). Castles are, according to their functions, classified into two: town castles and military castles. In the former castles people live permanently, but in the latter people do not. Military castles are occupied only in time of emergence. Beside the two types, two Japanese castles, two old mud walls, four beacon-post walls, and three warehouse-post walls are found in the Sacheon bay region. Castles are also classified into plain castles and mountain castles according to their location. Mud, stone, wood, and brick materials were used for castle and wall building. As the castles and walls of the bay region are precious cultural assets, they should be preserved and protected with much attention. It should be remembered that in the future they can be the most valuable tourist attractions all around.

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Analysis of energy security by the diversity indices: A case study of South Korea (다양성지수를 통한 에너지안보수준 분석: 한국사례를 중심으로)

  • Jang, Yong-Chul;Bang, Ki-Yual;Lee, Kwan-Young;Kim, Kyung Nam
    • Journal of Energy Engineering
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    • v.23 no.2
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    • pp.93-101
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    • 2014
  • How to determine the extent of national energy security? In this paper, we estimate it by comparative analysis of South Korea and other OECD countries in terms of energy diversity (fuel diversity). Energy security consists of 4 key factors such as availability, accessibility, acceptability, affordability. Especially the importance of accessibility can grow as local imbalance of supply and demand increases. As a proxy of the accessibility, fuel diversity can be a significant indicator to estimate a measure of energy security. In this paper, we use Shannon-Wiener index to measure energy diversity. If fuel diversity increases, the stability of energy security also should increase, because of the smoothing effect to lessen dependence on key energy sources. In 2012 Korean growth rate of H-index (energy diversity) is 18.38%, which is higher than other OECD countries. However, Korean H-index itself is 1.93, lesser than other countries. Shift from oil to coals/gas within fossil fuels has more impact on H-index than weight transition from fossil fuels to renewable energies in Korea. We conclude that more renewable energy is an effective solution to achieve higher energy diversity and ultimately higher energy security as the same as the German case.

Survey on Plant-Parasitic Nematodes in Peach Orchards in Gyeongbuk Province (경북지역 복숭아과원에 분포하는 식물기생성 선충의 조사)

  • 권태영;김동근;최충돈;윤재탁
    • Korean journal of applied entomology
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    • v.43 no.1
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    • pp.81-84
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    • 2004
  • Plant-parasitic nematodes were surveyed at peach orchards in Gyeongbuk province for three years from 2000 to 2002. Species, density, frequency, Simpson's index, Shannon and Wiener index, and prominence value were analyzed. Plant-parasitic nematodes were isolated from 97 orchards out of 124 orchards. More important plant-parasitic nematode genera on peach were Tylenchorhynchus nudus, Criconemoides informis, Paratylenchus elachistus, Pratylenchus vulnus, and Helicotylenchus digonichus. Aphelenchus sp., Tylenchus sp., Heterodera sp., Scutellonema sp. were found, but were not important. Root-knot nematodes were not found even though they were serious in foreign countried.

Flexible IP-based Multicast for Mobile Hosts in Internetwork (인터네트워크 기반 이동컴퓨팅의 유연성있는 IP 멀티캐스트)

  • 장경성;조근순;김용수;김병기
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 1998.05a
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    • pp.246-251
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    • 1998
  • 이동컴퓨터의 기술발전과 더불어 인터넷환경에서 다양한 서비스지원을 위한 이동성지원에 대한 연구가 최근에 활성화되고 있다. 그러나 다자간회의나 다양한 네트워크 환경을 조성하고 있는 인터넷으로 적용을 위해서는 인터레이스를 유연성 있게 지원하는 방법이 제시되어야 한다. IP 기반의 이동컴퓨팅 환경에서는 이동성지원을 위해서 이동호스트의 위치를 정의할 수 있는 Mobile-IP 연구와 멀티캐스트를 지원하는 멀티캐스트연구가 진행되고 있다. 본 논문에서는 IP 기반 이동컴퓨팅 환경에서 멀티캐스트를 지원하기 위한 요구사항을 연구분석하며 인터네트워크 환경으로 적용을 위한 다양한 인터페이스 지원 모델을 제시한다.

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Robust Optimization Using Supremum of the Objective Function for Nonlinear Programming Problems (비선형계획법에서 목적함수의 상한함수를 이용한 강건최적설계)

  • Lee, Se Jung;Park, Gyung Jin
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.38 no.5
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    • pp.535-543
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    • 2014
  • In the robust optimization field, the robustness of the objective function emphasizes an insensitive design. In general, the robustness of the objective function can be achieved by reducing the change of the objective function with respect to the variation of the design variables and parameters. However, in conventional methods, when an insensitive design is emphasized, the performance of the objective function can be deteriorated. Besides, if the numbers of the design variables are increased, the numerical cost is quite high in robust optimization for nonlinear programming problems. In this research, the robustness index for the objective function and a process of robust optimization are proposed. Moreover, a method using the supremum of linearized functions is also proposed to reduce the computational cost. Mathematical examples are solved for the verification of the proposed method and the results are compared with those from the conventional methods. The proposed approach improves the performance of the objective function and its efficiency.

Transit Mobility Measures on the Seoul Multimodal Network (대중교통망 이동성지표 개발(네트워크 분석을 중심으로))

  • Noh, Hyun-Soo;Doh, Tcheol-Woong;Kim, Won-Keun;Cho, Chong-Suk;Shin, Seong-Il
    • Journal of Korean Society of Transportation
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    • v.23 no.8 s.86
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    • pp.7-17
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    • 2005
  • Transportation is from an individual mobility. Various efforts to propose specific values or the individual mobility have been conducted in diverse transportation environment. However, mobility studies for multimodal public transportation are rare especially on not the range of line but area. This study propose a method to calculate transit mobility indices as expanding mobility analysis from point-to-point to area-to-area, considering access time to transit facility, running time and transfer time of passengers. To extract mobility indices, we included walking as a lowest category of mode and set passenger car as a competitive mode to transit mode. This study propose three public transportation mobility indices as 1) how competitive public transportation facility is offered against passenger car 2) how convenient transit mode including walking is provided against passenger car from origin to destination and 3) how many various paths are presented to support passenger's travel between regions. These indices are tested on the Seoul metropolitan area with 10 lines of urban rail and about 420 lines of bus. In addition, we proposed two political applications of proposed mobility indices to increase public transportation mobility between two regions and to maximize the mobility of study area when a line is added in the area.

A Study on factors affecting the viewer rating of"My Little Television": Focusing on SNS Big Data (마이리틀 텔레비전 시청률에 영향을 미치는 요인에 관한 연구 : SNS 빅데이터 중심으로)

  • Kim, Sang-Cheol;Kim, Kwang-Ho
    • Journal of Digital Contents Society
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    • v.17 no.1
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    • pp.1-10
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    • 2016
  • < My Little Television > with the new format which extends one person media broadcasting to terrestrial broadcasting is creating a huge Topic Index. It started the first broadcast on April 2015 and has continued the number one in viewer rating in the same time. While viewers directly participate in the program through the Daum TV Pod and a host communicates with viewers in a real time, various opinions are being reflected on the program. While a lot of information about the program has spread through SNS, it has led to raising the viewer rating of program. Recently, the Topic Index on the program has been published through the big data analysis rather than the program evaluation only by the viewer rating. The research on the correlation between the program viewer rating and amount of buzz has increased. In this study, it has analyzed how the Topic Index which is an extended concept of the amount of buzz affects the viewer rating. Study results show that the Topic Index is analyzed to positively influence the viewer rating. It will give a lot of help in studying big data of SNS on the program.