• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.5
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• pp.58-65
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• 2016

Recent frequent occurrence of urban sinkhole serves as a momentum of the periodic inspection of sewer pipelines. Sewer inspection using a CCTV device needs a lot of time and efforts. Many of previous studies which reduce the laborious tasks are mainly interested in the developments of image processing S/W and inspection H/W. However there has been no attempt to find meaningful information from the existing CCTV images stored by the sewer maintenance manager. This study adopts a cross-correlation based image processing method and extracts location data of sewer inspection device from CCTV images. As a result of the analysis of time-location relation, it shows strong correlation between the device's stand times and the sewer damages. In case of using this method to investigate sewer inspection CCTV images, it will save the investigator's efforts and improve the sewer maintenance efficiency and reliability.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.1
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• pp.78.2-78.2
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• 2011

2010년 천체투영관을 갖춘 9개 기관 천문관련 시설의 운영실무자들에게 설문지를 배포하여 시설 현황, 운영 및 교육 프로그램에 관한 사전조사를 실시하였다. 설문조사에서 천체투영관의 운영 활성화와 교육적 활용을 높일 수 있는 방안으로 시설 보완과 교육 프로그램 개발이 필요하다는 의견이 많았다. 특히 초등학생들을 위한 천문교육 프로그램 개발이 시급하다는 운영자들의 공통된 의견을 들을 수 있었다. 이번 연구에서는 1)국외에서 이용되고 있는 천체투영관 활용 교육프로그램을 조사하였고, 2) 조사결과를 기초로 우리의 현재 환경과 초등 과학과 교육과정 등을 고려하여 교육프로그램을 개발 하였다. 이번 발표에서는 국외에서 활용되고 있는 교육 프로그램들과 개발된 교육용 활동지 및 가이드북을 소개 하고자 한다. 개발된 교육용 활동지와 가이드북을 적극 활용할 경우 천체투영관의 운영 활성화와 교육적 활용을 극대화 할 수 있을 것으로 기대된다.

• Korean Journal of Materials Research
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• v.4 no.3
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• pp.357-363
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• 1994

The irradiation growth of the Zircaloy-4 cladding in the KOFA fuel loaded in the Kori-2 nuclear plant was measured to evaluate the irradiation growth behavior and to be compared with that of the Siemens cladding having different manufacturing process. Due to the partial recrystallization by final heat treatment, the KOFA Zircaloy-4 cladding showed a two step irradiation growth behavior such as the growth saturation and the accerlation which is typical of the fully annealed Zircaloy cladding. The difference in the measured irradiation growth rate between the KOFA and the Siemens cladding could be explained by the difference in the cladding texture which depends on the manufacturing process. From the measured irradiation growth data of Kori-2 KOFA fuel, a two-step irradiation growth model of the KOFA Zircaloy-4 cladding was derived, the accuracy of which can be more clearly verified as the measured data of the irradiation growth are accumulated in the future.

• Proceedings of the Korea Contents Association Conference
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• 2011.05a
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• pp.209-210
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• 2011

본 연구는 학교보안관 제도에 대한 학부모 인식을 조사하는데 목적을 두고 있다. 이를 위하여 이 연구에서는 서울시 4개구를 무작위로 선정하여 107명을 추출하여 분석하였다. 설문지의 타당도는 전문가회의와 요인분석, 신뢰도는 신뢰도 분석을 통하여 검증하였다. 통계처리는 카이스퀘어 검증과 t검정, F검정 등이 실시되었다. 결론은 다음과 같다. 첫째, 개인적 특성에 따라 학교보안관 제도의 필요성은 차이가 있다. 둘째, 개인적 특성에 따라 학교보안관의 학교생활 도움정도는 차이가 있다. 셋째, 개인적 특성에 따라 학교보안관 만족은 차이가 있다.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.28 no.4
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• pp.127-156
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• 2017

This study aims to identify the problems of services for the disabled in Presidential archives and to propose methods to solve those problem. To achieve the goal this study conducted literature surveys such as existing researches, laws and surveys on people with disabilities, and conducted case studies on domestic institutions that provide similar services with archives and US Presidential Archives. Also, information disclosure request was made to the service representatives in Presidential Archives and we analyed the current status of offline services for the disabled who visited Presidential Archives based on the results of literature review, case studies and information disclosure request. As a result, the problems were found in terms of space and facilities, assistive devices, programs and manpower and we proposed the methods to improve the services for the disabled.

• Journal of The Korean Association For Science Education
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• v.20 no.2
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• pp.244-249
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• 2000

Using a sample of 83 secondary school science teachers, this study investigated the views on science and learning which they have. Questionnaires used in this study were the same that Kwon & Pak(1995) administered. Both 'Questionnaire for Perception of Nature of Science' and 'Questionnaire for Constructivistic Views of Learning' were 11-point scales. Data analyses were done by using t-test and ANOVA. The secondary science teachers showed a relativistic, deductivistic, instrumental, and process-oriented views on science. The younger age of the teachers, the more emphasis on process rather than content. Female teachers had more relativistic, instrumental, and process-oriented views than male teachers had. The teachers sampled in this study showed a constructivistic view on learning. Finally, the teachers' views of science and learning were closely related each other.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.11 no.1
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• pp.1-6
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• 1999

Nearshore and offshore pipelines are often applied to carry oil, gas, water and combined products. The thermal and pressure gradients of the fluid inside pipeline cause pipeline expansion. This expansion produces stress to connecting structures with pipeline. Should this stress exceeds the yield strength of connecting components or the allowable displacement of the system, a damage can occur. As most pipelines contain hazardous and toxic fluids, the damage usually leads to fatal accidents involving great economic loss as well. Even subsea pipelines can be easily applied to transport liquid type fluid without time and space constraint, they should be designed and maintained carefully to be functional safely during design lifetime. In this paper, various theories estimating pipeline thermal expansion are investigated and the effects of pipe components to expansion are studied.

• Journal of Korean Society of Archives and Records Management
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• v.22 no.1
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• pp.133-157
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• 2022

Special subject archives in different fields have been established and the related studies have been constantly made so far, but no evaluation index reflecting the characteristics of the archives has yet been developed. Thus, this study intends to develop a draft of the special subject archive operation evaluation index through literature research and propose the special subject archive operation evaluation index through a Delphi survey. A Delphi survey was conducted thrice, with 10 persons in charge of archiving thematic archives in 5 fields. Finally, a special subject archive operation evaluation index consisting of 4 evaluation categories, 10 evaluation items, and 28 detailed items was proposed. This study is significant because it was the first in Korea to develop and propose an operation evaluation index for special subject archives.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.3
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• pp.585-592
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• 2017

Most sewer lines buried in the city are likely to be collapsed due to serious aging. Also, due to the high concentration of development and high population density and traffic, the collapse of the sewer will cause enormous social and economic damage. Therefore, proactive maintenance is required to prevent accidents caused by deteriorated sewer pipe. In order to utilize limited budget effectively, risk-based prioritization methods should be proposed that simultaneously consider the consequence of failure and the probability of failure. In this study, the method of risk-based prioritization of sewer was examined by reviewing various cases of overseas studies and applied to the urban sub-catchment. First, the impact factors that can be secured through the sewer GIS DB in Seoul were derived, and the weight, sub-criteria, and impact score of each impact factor were determined and the consequence of failure was calculated by weight sum method. In addition, the probability of failure was calculated by dividing the service life by the estimated useful life, and the consequence of failure and the probability of failure were classified into five grades by the Jenks natural breaks classification method. The prioritization method was applied to sub-catchment in the Seoul to derive a risk matrix and a risk grade. As a result, 26% of all subjects were selected as the inspection priority subjects with 4-5 risk grade. Therefore, using the risk-based CCTV prioritization methodology, it will be possible to systematically determine the objects that need investigation first.

• Journal of the Korean Geosynthetics Society
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• v.17 no.3
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• pp.47-55
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• 2018

Recently, increasing number of urban ground subsidence occurrences has been identified. This situation is mainly due to the increased number of underground cavities. This study is intended to develop the method that prevents ground settlement caused by deteriorated or damaged sewers, which are the main cause of land subsidence. To that end, GPR exploration was conducted using CCTV monitoring of deteriorated sewer at the location with high settlement potential. Through such CCTV monitoring and GPR investigation, abnormal ground behavior was monitored at the site where sewer was damaged, joint was cracked and soil was deposited. According to site investigation in this study, evaluation method using correlation analysis of CCTV monitoring and GPR investigation results is expected to prevent ground settlement attributable to damaged sewer.