• 펄프종이기술
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• 제31권2호
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• pp.58-63
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• 1999

Three kinds of papers were prepared from different beating degree of pulps. Physical and optical properties were examined to elucidate the deterioration mechanism of paper according to beating degrees. Changes of double folds, elongation, water retention value, DP, K/S value and visible, UV region light absorption spectra of those papers treated by UV light were studied. Double folds and brightness were decreased more rapidly by UV treatment with increasing of beating degree. The light absorption rates of pulps in visible and UV region were also increased with change of beating level. The formation of new hydrogen bonds and higher light absorption rate of pulps according to beating induced to absorb and interact with much UV light. These phenomena maybe brought about to accelerate paper deteriortion by UV treatment both optical and physical properties.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1990년도 가을 학술발표회 논문집
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• pp.45-50
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• 1990

This study develops practical models and methods for the assessment of safety and capacity rating of existing P.C. girder bridges based on the reliability methods. One of the main objectives of the study is to propose a practical but realistic limit state model for safety assessment and LRFR rating criteria, which explicitly incorporates the degree of deterioration and damage as well as actual condition of P.C. girder bridges in terms of the damage factor and the response ratio. The damage factor proposed in the paper is defined as the ratio of the current estimated stiffness to the intact base-line stiffness of a member. Based on the observation and the results of applications to existing bridges, it may be concluded that the proposed methods for the assessment and capacity rating models, which explicitly account for the uncertainties and effects of degree of deterioration or damage, provide more realistic and consistent safety-assessment and capacity rating.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2020년도 봄 학술논문 발표대회
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• pp.31-32
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• 2020

Concrete changes its internal moisture distribution depending on the external environment, and changes in the condition of the material's interior over time affect the performance of the concrete. These effects are closely related to the long-term behavior and durability of concrete, and the degree of deterioration varies from climate to climate in each region. In this study, we use actual climate data from each region with distinct climates. A multi-physical analysis based on the method was conducted to predict the difference and degree of deterioration rate by climate.

• 한국구조물진단유지관리공학회지
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• 제17권2호
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• pp.36-44
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• 2013

• 전기학회논문지
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• 제64권12호
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• pp.1768-1775
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• 2015

Recent major domestic facilities, such as nuclear power plants, many control cables are installed and are degraded by long-term use, but research on deterioration diagnosis is lacking. In the event of a fault in the cable due to deterioration can be developed into a major accident such as the main plant is stopped, so the deterioration diagnostic techniques of high reliability for the cable is required. In this paper, proposes a methodology using a cable resonance that can effectively diagnose the deterioration of the cable. Prior to the test, we developed a setup for stable measuring the characteristics of the cable and it verified the suitable of the measurement set-up in terms of interactivity and reliability, also measured S-parameters applying verified measurement set-up to the cables that deterioration degree is different. Then, we had amplified the difference in resonance frequency between the healthy state and the deteriorated state using connection in a series of measured S-parameters. In a result from the method, we have verified that the more deteriorate the cables is, the more decrease the resonance frequency is. Measured results are justified by inducing the resonance frequency calculation of the cable from the S- parameters represented by the hyperbolic function formula. VNA(Vector Network Analyzer) for S-parameter measurements used in this study is Agilent E5061B and shielded twisted-pair cables was used for deterioration diagnostic test.

• 농업생명과학연구
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• 제46권1호
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• pp.17-27
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• 2012

본 연구는 산악형 국립공원으로 분류된 6개 국립공원 53개 노선 204.5 km 구간을 대상으로 탐방로의 물리적 특성 및 훼손유형, 훼손정도 등을 파악하여 공원관리를 위한 기초자료로 활용하기 위해 수행되었다. 탐방로의 물리적 특성을 조사한 결과, 노면의 평균경사는 $14.6^{\circ}$, 평균 노폭은 1.5 m, 평균 나지폭은 1.1 m로 조사되었고, 훼손유형은 6개의 유형이 2,686회 나타났으며, 노면침식 현상이 전체 훼손유형의 37%로 가장 많은 발생을 보였다. 다음으로 뿌리노출 현상, 노폭확대 현상, 분기 현상, 암석노출 현상, 비탈붕괴 현상 순으로 조사되었고, 훼손정도를 조사한 결과, "건전" 구간이 165.34 km로 80.9%를 차지하고 있었고, "강" 구간이 9.08 km, "중" 구간이 12.69 km, "약" 구간이 17.39 km로 훼손구간은 39.16 km에 훼손율은 19.1%로 조사되었다.

• 토지주택연구
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• 제4권1호
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• pp.65-75
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• 2013

노후 공공임대주택은 노후화 관리를 위해 주거환경개선을 지속적으로 시행하며 최근 3년간 시설개선사업을 통해 기본적인 노후화 관리를 수행하였다. 이에 따라 본 연구는 주거단지 노후화에 따른 주거환경요소의 개선 요구도 및 현 주거환경 만족도 조사를 통해 기 시행된 시설개선사업의 효과에 대해 알아보고 추후 시설개선사업의 계획방향을 제시하고자 하였다. 이를 위해 전국 장기공공임대주택의 거주자를 대상으로 설문조사를 하였으며 만족도 및 중요도에 대해 평균값 분석을 하고 항목간의 유형구분을 위해 요인분석을 하였다. 그 결과 주거환경개선 항목으로 도출한 공용 공간 29개 항목을 6개의 요인으로 구분하고, 세대 내부 공간 28개 항목을 4개의 요인으로 구분하여 만족도 및 중요도에 대한 평균값을 비교하였다. 결론적으로 주민의식조사 결과를 종합하여 추후 시설개선 사업을 중심으로 타 주거환경개선사업과 연계한 추진방향을 제안하였다.

• 한국환경과학회지
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• 제24권11호
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• pp.1431-1442
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• 2015

This study was carried out to systematically maintain and manage the trails by assessing the physical characteristics, the types of deterioration and impact rating class of trails located in Mt. Nam District of the Gyeongju National Park. The major trails followed 6 routes including Sambulsa-Geumobong(A), Yongjangsaji-Geumobong(B), Yongjanggol-Yiyoungjae-Gowibong(C), Cheonusa-Gowibong(D), Sangseojang-Forest road(E) and Tongiljeon-Forest road(F). The routes length of A was 2.2 km, 2.7 km of B, 3.4 km of C, 1.3 km of D, 2.0 km of E and 1.0 km of F. In the physical characteristics, A was the widest and F was the narrowest in the width and bared width of trail. In depth of erosion, B was the deepest and E was the shallowest. D was the steepest and E was the gentlest in the slope. In the results of analysing the types of deterioration, A were 13 types, 11 types of B, C and D, 10 types of E and 6 types of F. The times of appearance of deterioration types in A were 86 times, 75 times of B, 105 times of C, 48 times of D, 47 times of E and 13 times of F. In case of the impact rating class, trail erosion was II degree, I degree of trail expansion, root exposure, trail divergence and rock exposure.

• 한국인터넷방송통신학회논문지
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• 제17권2호
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• pp.239-244
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• 2017

전력 수요는 매년 증가추세에 있으며, 이에 따라 발전소에서 동작하는 모든 장비들과 대용량의 장거리 전력수송을 위한 장비들은 신뢰할 수 있는 수준에서 완전한 상태로 동작하여야 한다. 발전소에서 생산한 고전압 전력을 전달하기 위해 사용하는 케이블은 주로 6.6 kV XLPE 케이블(또는 CV케이블)이다. 제작 기술, 설치환경 및 사용조건에 다르겠지만, 케이블은 동작함과 동시에 열화과정이 진행된다. 접속재의 경우, 제조 결함이나 공사 결함이 있는 경우 대체로 동작 후 약 3 년 내에 고장을 일으키며, 그렇지 않는 경우 수명이 20-30 년을 지속하는 경우가 많다. 우리는 케이블의 열화 상태를 감시하기 위한 장비를 개발하여 충남 태안의 한국서부발전주식회사(Korea Western Power Co. Ltd.)에 설치하였다. 우리는 이 논문에서 케이블의 열화 판정의 기준을 설정하고, 기준에 따른 열화정도를 판정하고, 케이블의 대체여부를 결정함으로써 발전소에서 설치된 활선 케이블의 동작 상태를 감시한 결과와 케이블을 구성하고 있는 절연체와 방식층이 절연저항 특성에 미치는 영향 및 케이블의 동작에 미치는 영향을 연구한 결과를 제시한다.

• 펄프종이기술
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• 제30권2호
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• pp.24-29
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• 1998

This study was carried out in order to elucidate the deterioration mechanism of paper according to various sizing chemicals. No additive paper and four kinds of papers containing rosin-alum, alum only, alkylketene dimer(AKD)-cation polymer and cation polymer only were treated by UV light to study changes of water-resistant, optical and mechanical properties from the view points of natural deterioration of paper. Since rosin chemicals have UV absorption at the relatively long wavelength region, rosins are degraded to form hydrophilic groups such as carboxylic acid from their double bonds by UV treatments. These phenomena caused the decreasing of sizing degree and wetting time in case of rosin-sized paper, while the UV treatments brought about the slight increase of wetting time in rosin-free papers such as no additive, alum and kymene only paper owing to the auto-sizing effect. Optical properties were primarily influenced by sizing chemicals. Rosin-sized paper showed lower brightness after UV and near UV treatment because of its UV instability.