• 제목/요약/키워드: Ground current

검색결과 1,725건 처리시간 0.031초

어구 자동 식별을 위한 NB-IoT 기반의 해양 트래커 부이 시스템의 전력 절감 (Power Save of Marine Tracker Buoy System Based on NB-IoT for Identification of Fishing Gear)

  • 남성일;김민훈
    • 한국항행학회논문지
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    • 제22권6호
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    • pp.545-550
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    • 2018
  • 해양수산부는 2016년 유실어구에 의한 피해를 최소화하기 위해 전자어구실명제 실행계획을 발표하였다. 어구의 과다사용 및 폐어구 저감을 위해 어구의 종류 및 위치, 사용자의 실명을 포함한 정보를 IoT 기반의 통신을 이용하여 어선 및 관제센터에 효율적으로 전송할 수 있는 기술이 필요하다. 그 중 트래커 해양 부이 시스템은 사물 인터넷 기반의 통신 기술 중 하나인 NB-IoT통신을 이용하여 부이의 위치 및 수집된 상태정보를 관제센터에 전송하는 시스템으로써 장시간 해상에 배치되어 운용된다. 본 논문에서는 해양 트래커 부이 시스템을 저 전력으로 운용하기 위한 알고리즘을 제안하고, 제안하는 알고리즘에 따라 설계 제작된 부이 장치의 소비 전류를 측정하고 그 결과를 분석하였다.

광해방지 국제심포지엄 발표사례로 본 국가별 광해 및 복구현황과 정책 (Review on Current Status on Mine Reclamation Policies of 9 Countries represented by International Symposium)

  • 이승아;양인재
    • 한국자원공학회지
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    • 제55권6호
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    • pp.546-552
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    • 2018
  • 금번 6차 광해방지 국제심포지움 발표사례로 볼 때, 국가별 광산개발의 역사, 지리여건, 경제상황 등이 상이하나, 과거 개발된 광산으로 인해 발생한 산성광산배수로 인한 수질오염, 광물찌꺼기 유실로 인한 토양오염 및 수질오염, 사면파괴로 인한 산사태, 지하갱도 붕괴로 인한 지반침하 등으로 인간의 생활이 위협당하고 있다. 나라별로 기술력과 법제도의 차이가 있고, 광해복구가 진행 중인 나라와 이제 시작하려고 제도마련 및 기술지원을 받아야 하는 나라도 있다. 광해복구를 시작하려는 나라에서는 국제사회에 도움을 요청하고 있어 기술적 제도적으로 앞선 선진국에서는 복구를 시작하려는 나라와 공조를 통해 광해를 복구해야할 필요가 있다.

커피 로스팅 공정에서 발생되는 향기물질의 유해성 고찰 및 노동자 건강보호 방안 (A Review on the Hazards of Flavoring Chemicals in Coffee Roasting Proces)

  • 임경택
    • 한국산업보건학회지
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    • 제29권2호
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    • pp.119-140
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    • 2019
  • Objectives: This study was based on the occurrence of a coffee roasting process-related disorder(bronchiolitis obliterans; published by NIOSH in the US) among workers exposed to chemicals called diacetyl in a coffee processing facility. Flavorings added to coffee contain diacetyl and 2,3-pentanedione, all of which are subject to exposure in a number of food manufacturing processes, including coffee roasting, grinding, and packaging. Therefore, this study aims to review the toxicity to workers related to food processing and food additive manufacturing to prevent occupational diseases. Methods: We surveyed the related literature, domestic and international references, and the status of relevant domestic and foreign professional organizations. The present situation of workers was investigated by reviewing literature on the safety and health of workers in the coffee roasting process using domestic and foreign literature and presentations. Expert advisory opinions were reflected, and experts were consulted by participating in domestic and overseas academic conferences. Results: Most of the fragrance materials for coffee were harmful and hazardous substances according to the GHS classification, and research was carried out through a second external consultation. A literature review on the measurement of air pollutant emissions from coffee roasters and the estimation of air pollutant emissions during coffee roasting examined the characteristics of pollutants emitted during coffee roasting. Conclusions: Two chemicals identified as causing bronchiolitis obliterans in the coffee roasting process are believed to explain why the disease is difficult to treat. This information can be used effectively in the future prevention of this disease. Future studies should clearly identify the potential for toxicity of alpha-diketones and the bases of OELs in relation to the occurrence of obstructive bronchiolitis, including measurement of various organic compounds and alpha-diketones from ground coffee, as well as various coffee grinds and coffee bean varieties. In particular, it is necessary to clarify the current understanding of the dose-response relationship between alpha-diketone and lung disease in workers involved in coffee roasting.

조선왕실(朝鮮王室)의 태실석물(胎室石物)에 관한 일연구(一硏究) -서삼릉(西三陵) 이장(移藏)원 태실(胎室)을 중심(中心)으로- (A research on the stone ornaments of Taesils of Joseon royal family)

  • 윤석인
    • 헤리티지:역사와 과학
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    • 제33권
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    • pp.94-135
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    • 2000
  • Rituals for burying the tae(胎) is a unique royal tradition of Korea that lasted from Unified Shilla(統一新羅) Kingdom to Joseon(朝鮮) dynasty. However, all of the currently known taesil(胎室)s are of the royal descendants of Joseon dynasty. Therefore, Taesils made earlier than Joseon dynasty are only known by historical documents. Taesils of the royal descendants of Joseon Dynasty divide into two kinds. One is for those of princes and princesses and the other is for those of Kings. The structure of taesils of princes and princesses is a stone chest(石函) in a pit which dug on the apex of the Taebong(胎峰) containing a pair of Tae(胎)-urn(the inner urn and outer urn), a stone tablet called Jiseok(誌石) which the date of baby's birth and Tae burial is inscribed in. And a tombstone-shaped stone tablet which called Taesilbi(胎室碑) was built on the ground. And the underground structure of Taesils of Kings is identical with that of taesils of princes and princesses, but instead of just an stone tablet, this has a Budo(浮屠);means stupa of a monk in korean)-shaped stone structure on the top of the stone chest, and an octagon-shaped porch was built around it, and a Tapbi(塔碑) was built. This treatise is focused on the current status and change process of stone ornaments. The subject of this treatise is 54 Taesils which were transferred to Seosamnung(西三陵) during the japanese occupation and Tae-urns and Jiseok(誌石)s from any other Taesil and its stone chest were not included in this treatise. Researches on Taesils can be great help to history by providing resources about genealogy of Jaseon royal family and social, economical status of that time. And researches on stone ornaments and tae-urns from Taesils can provide great help to stone art history and porcelain history of Joseon dynasty.

Vascular plant diversity of the Gogunsan Archipelago in the Korean Peninsula

  • Kim, Jung-Hyun;An, Ji-Hong;Nam, Gi-Heum;Park, Hwan-Joon;Kim, Jin-Seok;Lee, Byoung Yoon;Lee, Kyeong-Ui;Chang, Yeon-Soon
    • Journal of Species Research
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    • 제8권1호
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    • pp.136-159
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    • 2019
  • This study was carried out to investigate the flora of six islands belonging to the Gogunsan Archipelago (i.e., Sinsi-do, Seonyu-do, Munyeo-do, Yami-do, Bian-do, and Duri-do) in the Korean Peninsula. As results of five field surveys from March to October of 2016, we have identified 575 total taxa, representing 527 species, five subspecies, 42 varieties, and one hybrid, placed in 358 genera and 118 families. Of these 575 taxa, four are endemic to Korea, six taxa are listed on the Korean Red List of threatened species, 67 are floristic regional indicator plants, and 74 are invasive alien species. In this study, we compared species richness among the islands, and find that the larger the islands, the higher the species richness. In the case of habitat affinity types, forest species were most common, followed by farmland, seacoast, bare ground and wetland species. From similarity analyses based on the composition of vascular plants, each island did not exhibit either local specificity or unique diversity. On the contrary, the proportion of invasive alien and ruderal species may increase by human activities. Investigations and analyses of island flora such as this are important to assess the current status of the flora, predict future vegetation patterns and the spread of the alien species, and establish managment plans of plant diversity.

옥외공간에서 수목의 다기능을 고려한 최적의 배식 위치 선정 모델 - 수목의 그림자 효과, 시야차단, 개방성을 고려하여 - (Optimal tree location model considering multi-function of tree for outdoor space - considering shading effect, shielding, openness of a tree -)

  • 박채연;이동근;윤은주;모용원;윤준하
    • 한국환경복원기술학회지
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    • 제22권2호
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    • pp.1-12
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    • 2019
  • Open space planners and designers should consider scientific and quantified functions of trees when they have to locate where to plant the tree. However, until now, most planners and designers could not consider them because of lack of tool for considering scientific and quantitative tree functions. This study introduces a tree location supporting tool which focuses on the multi-objective including scientific function using ACO (Ant colony optimization). We choose shading effect (scientific function), shielding, and openness as objectives for test application. The results show that when the user give a high weight to a particular objective, they can obtain the optimal results with high value of that objective. When we allocate higher weight for the shading effect, the tree plans provide larger shadow value. Even when compared with current tree plan, the study result has a larger shading effect plan. This result will reduce incident radiation to the ground and make thermal friendly open space in the summer. If planners and designers utilize this tool and control the objectives, they would get diverse optimal tree plans and it will allow them to make use of the many environmental benefits from trees.

Improving Information Service for Earthquake Using Rapid ShakeMap

  • Hwang, Jinsang;Ha, Ok-Kyoon
    • 한국컴퓨터정보학회논문지
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    • 제26권5호
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    • pp.95-101
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    • 2021
  • 본 연구는 지진의 영향을 등치선의 형태로 표현할 수 있는 Shake을 활용하여 현행 지진재난 정보제공 서비스를 개선하는 방법에 관한 것이다. 미국 지질조사국이 제공하고 있는 ShakeMap 소프트웨어를 사용하여 자동화된 신속 ShakeMap 생성 시스템을 구현하였으며 이를 바탕으로 지진발생 후 사용자의 위치를 기준으로 지진의 위험도를 진도나 지반최대가속도의 형태로 파악할 수 있는 지진재난 정보서비스 개선모델을 제시하였다. 개선된 모델의 구현 가능성과 효과를 검증하기 위하여 경북 포항지역을 대상으로 지진재난 정보서비스앱을 개발하여 시범적으로 운영한 결과 신속 ShakeMap을 활용한 정보제공을 통해 보다 상세한 지진위험도 정보를 제공함으로써 사용자의 안전행동을 보다 효과적으로 유도할 수 있음을 확인할 수 있었다.

국내 오염토양 반출정화사업 현황 (The Occurrence and Treatment Status of Off-site Contaminated Soils in Korea)

  • 한수호;정명채;김정욱;전순원;누엔 쿠억 트안;윤경욱;민선기
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제25권4호
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    • pp.1-6
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    • 2020
  • Recently, ex-situ remediation technologies has been emerging to clean up contaminated soils mainly because the in-situ techniques have limited applicability and technical difficulties in relatively small contaminated sites. Accordingly, implementation of off-site treatment and disposal have been continuously increased in soil remediation and restoration projects in Korea. However, in many cases, reclaimed soil is still not properly recycled or reused. Therefore, there is an urgent need to document the current status of soil management practices in soil remediation projects in the nation. This study presents a survey of soil contamination status and remedial approaches in Korea based on soil cleanup projects completed in 2015 - 2019, and proposes the possible options of the recycling or reusing the reclaimed soils under compliance with related regulations. The results of the soil survey showed soil contamination was most severe in gas stations, industrial facilities, and military areas. The major types of pollution were related to the petroleum-contaminated site (TPH and BTEX) with 77.0% occurrence in all the contaminated sites. The reclaimed soils were mostly reused as a ground filling-up soils in industrial facilities (60.0%) and warehouses (37.0%).

Design and Implementation of Mobile 3D Visualization Service System on the Integrated Underground Geospatial Information Map

  • Cho, Sook-Kyoung;Kim, Yong-Tae;Choi, Ja-Young
    • 한국컴퓨터정보학회논문지
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    • 제25권12호
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    • pp.173-186
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    • 2020
  • 본 논문에서는 지하공간 통합지도를 탐사 현장에서 활용하기 위한 모바일 단말기용 서비스 시스템을 설계 구현한다. 모바일 단말기용 현장활용 서비스 시스템은 지하공간 통합지도 관리 시스템에서 제공하는 타일맵, 3차원 지형정보, 지하구조물, 지하시설물, 지반정보 등을 현재 위치에 따라 3차원으로 가시화하도록 설계되었고, 현장 탐사로 얻어진 결과를 실시간으로 반영하도록 설계되었다. 또한, 제안된 시스템은 모바일 단말기의 무선 네트워크 및 기기 특성에 따른 제약 문제로 지하공간 통합지도를 glTF 포맷 형태로 전송 후 가시화 하도록 구현하였다. 구현된 모바일 서비스 시스템은 지하공간 탐사 현장에서 3차원으로 지도 및 공간 객체들을 가시화하여 사용자에게 정확하고 통합된 지하공간 데이터를 제공함으로써 탐사 현장에서의 사고 발생을 방지할 수 있다. 그리고, 갱신된 지하공간 데이터를 실시간으로 지하공간 통합지도 관리 시스템에 전송하여 최신성과 정확성을 유지할 수 있다.

Seismic analysis of high-rise steel frame building considering irregularities in plan and elevation

  • Mohammadzadeh, Behzad;Kang, Junsuk
    • Steel and Composite Structures
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    • 제39권1호
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    • pp.65-80
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    • 2021
  • Irregularities of a building in plan and elevation, which results in the change in stiffness on different floors highly affect the seismic performance and resistance of a structure. This study motivated to investigate the seismic responses of high-rise steel-frame buildings of twelve stories with various stiffness irregularities. The building has five spans of 3200 mm distance in both X- and Z-directions in the plan. The design package SAP2000 was adopted for the design of beams and columns and resulted in the profile IPE500 for the beams of all floors and box sections for columns. The column cross-section dimensions vary concerning the number of the story; one to three: 0.50×0.50×0.05m, four to seven: 0.45×0.45×0.05 m, and eight to twelve: 0.40×0.40×0.05 m. Real recorded ground accelerations obtained from the Vrancea earthquake in Romania together with dead and live loads corresponding to each story were considered for the applied load. The model was validated by comparing the results of the current method and literature considering a three-bay steel moment-resisting frame of eight-story height subject to seismic load. To investigate the seismic performance of the buildings, the time-history analysis was performed using ABAQUS. Deformed shapes corresponding to negative and positive peaks were provided followed by the story drifts and fragility curves which were used to examine the probability of collapse of the building. From the results, it was concluded that regular buildings provided a seismic performance much better than irregular buildings. Furthermore, it was observed that building with torsional irregularity was more vulnerable to seismic failure.