• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.7
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• pp.80-86
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• 2019

As computer performance improves, research using deep learning are being actively carried out in various fields. Recently, deep learning technology has been applying to the safety evaluation for structures. In particular, the internal blades of a turbine structure requires experienced experts and considerable time to detect surface damages because of the difficulty of separation of the blades from the structure and the dark environmental condition. This study proposes a Faster R-CNN deep learning model that can detect surface damages on the internal blades, which is one of the primary elements of the turbine structure. The deep learning model was trained using image data with dent and punch damages. The image data was also expanded using image filtering and image data generator techniques. As a result, the deep learning model showed 96.1% accuracy, 95.3% recall, and 96% precision. The value of the recall means that the proposed deep learning model could not detect the blade damages for 4.7%. The performance of the proposed damage detection system can be further improved by collecting and extending damage images in various environments, and finally it can be applicable for turbine engine maintenance.

• Safe Food
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• v.3 no.1
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• pp.13-21
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• 2008

우리나라 학교급식의 현재 성적표를 "양적 성공, 질적 실패"로 평가할 수 있다. 2003년 학교급식이 국가적 교육사업이 되어서 초 중 고 특수학교에서 전면급식이 이루어지고 10,343개교에서 704만명의 학생에게 급식을 제공하고 있다. 현재는 양질의 학교급식을 안전하고 저렴하게 공급하고, 국가식량정책과 연계하여 효율적으로 관리하여야 할 시기이다. 그러나 학교급식 소요경비 연 2조3천억원, 영양사 7,196명 등 63,145명이 종사하는 거대한 산업군이라는 규모에도 불구하고 전체 학교의 70%만이 식당시설을 갖추고 있고 급식 만족도가 학생이나 학부모의 기대에 미치지 못하고 있으며, 식중독 발생의 원흉이 되어 국민적 질책의 대상이 되고 있는 것이 현실이다. 이 문제는 1) 영양사 업무과중에 따른 시간부족, 영양사 지식정보 부족 등에 따른 식재료 및 위생관리 소홀, 2) 냉장, 냉동, 오염/비 오염 구획 등에 필요한 시설과 설비 부족, 3) 교육인적자원부의 급식위생관리의 전문성 부족과 담당 인력 및 정책적, 재정적 지원 부족을 원인으로 볼 수 있다. 학교급식 안전대책은 아래 20대 과제를 추진하여 확보하여야 할 것이다. 전략 1은 "우수한 식재료 위생관리"로서 "급식비 인상 및 현실화, 철저한 수입 농수축산물관리, 식재료 공급 및 전처리업 자유업에서 신고제, 허가제로 전환, GAP(우수농산물관리) 제도 도입, 생산이력제도(traceability) 도입, 급식원료 "품질인증 제도" 도입, 식품원료 전처리 시 세척, 소독프로그램 보급, 학교급식 식자재기준, 규격 설정, 과학적이고 쉬운 검수지침 개발 및 보급, 신속검사키트를 활용한 주기적인 미생물 검사 의무화, 위생 전문가에 의한 검수, 식재료별로 분산된 법령과 관리제도 정비(식품안전기본법), 급식식자재 공급 유통 과정의 감시 감독 강화" 등 13개 과제를 제안한다. 전략 2는 "급식위생 확보 인프라구측"으로서 "급식종사자 전문성 확보(조리/영양/위생), 급식전담기구(학교급식진흥원 /학교급식센터 등) 설치, 급식형태 다양화(위탁/직영 균형 발전), 학교급식법 재개정, 학교급식 HACCF제도 확대" 등 4개 과제를 제안한다. 전략 3은 "급식소 시설 설비 현대화 및 환경개선"으로서 "급식시설 설비 현대화 (전처리실, 냉장고, 온장고 구비 등), 급식소 환경 개선 (상수 사용 확대 및 안전강화, 지하수 소독 강화, 정화된 공기 공급 등)" 등 2개 과제를 제안한다. 전략4는 "급식위생제도 및 관리체계 개선"으로서 "전문적 단일기관 안전관리 (식품안전처)" 과제를 제안한다.

• Journal of Navigation and Port Research
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• v.29 no.6 s.102
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• pp.481-485
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• 2005

The port entry system of the inner harbor in Pyeongtaek${\cdot}$Dangjin was planned as lock-gate in 'Master plan project on port planning in Asan industry base(1990)‘, but was changed to tidal harbor in 'Project maintaining Master plan for comprehensive development of Pyeongtaek${\cdot}$Dangjin port(2001)'. Accordingly, southern sea bank constructed under the lower part of Seohae-bridge will be removed so that inbound/outbound vessels for the inner harbor can navigate at all times. However, in the view of the safety on passing through the lower of Seohae-bridge, navigating conditions for the inner harbor will be restricted in the single-way of 50,000 DWT vessel and the two-way of vessel less than 30,000 DWT Therefore, this study carried out the estimation of traffic congestion arising from these vessels with above restrictions q[ter supposing annual inbound/outbound vessel's numbers for loading and unloading cargo surveyed on the inner harbor.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.29 no.1
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• pp.191-195
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• 2005

The port entry system of the inner harbor in Pyeongtaek (Asan) was planned as lock-gate in 'Master plan project on port planning in Asan industry base(1990)', but was changed to tidal harbor in 'Project maintaining Master Plan for comprehensive development of Pyeongtaek (Asan) port(2001)'. Accordingly, southern sea bank constructed under the lower part of Seohae-bridge will be removed so that inbound/outbound vessels for the inner harbor can navigate at all times. However, in the view of the safety on passing through the lower of Seohae-bridge, navigating conditions for the inner harbor will be restricted in the single-way of 50,000 DWT vessel and the two-day of vessel less than 30,000 DWT. Therefore, this study carried out the estimation of traffic congestion arising from these vessels with above restrictions after supposing annual inbound/outboubd vessel's numbers for loading and unloading cargo surveyed on the inner harbor.

• Journal of Korea Water Resources Association
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• v.55 no.8
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• pp.623-634
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• 2022

Due to river maintenance projects such as the creation of hydrophilic areas around rivers and the Four Rivers Project, the flow characteristics of rivers are continuously changing, and the risk of water quality accidents due to the inflow of various pollutants is increasing. In the event of a water quality accident, it is necessary to minimize the effect on the downstream side by predicting the concentration and arrival time of pollutants in consideration of the flow characteristics of the river. In order to track the behavior of these pollutants, it is necessary to calculate the diffusion coefficient and dispersion coefficient for each section of the river. Among them, the dispersion coefficient is used to analyze the diffusion range of soluble pollutants. Existing experimental research cases for tracking the behavior of pollutants require a lot of manpower and cost, and it is difficult to obtain spatially high-resolution data due to limited equipment operation. Recently, research on tracking contaminants using RGB drones has been conducted, but RGB images also have a limitation in that spectral information is limitedly collected. In this study, to supplement the limitations of existing studies, a hyperspectral sensor was mounted on a remote sensing platform using a drone to collect temporally and spatially higher-resolution data than conventional contact measurement. Using the collected spatio-temporal hyperspectral images, the tracer concentration was calculated and the transverse dispersion coefficient was derived. It is expected that by overcoming the limitations of the drone platform through future research and upgrading the dispersion coefficient calculation technology, it will be possible to detect various pollutants leaking into the water system, and to detect changes in various water quality items and river factors.