• Title/Summary/Keyword: Construction accidents

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A Study on the Reinforcement of Bridge Foundation in the Limestone Cavity (석회암 공동지역의 교량기초 보강에 관한 연구)

  • Lee, Sang-Chul;Ryu, Chang-Yeol;Cho, Kook-Hwan
    • Journal of the Korean Society of Hazard Mitigation
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    • v.11 no.1
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    • pp.51-57
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    • 2011
  • Irregular distributions of limestone cavity in Gang-Won province area may cause unexpected accidents from reduced serviceability or failure of structure. It is requested that an appropriate ground reinforcement method should be used to improve bearing capacity of structure, and the method should also be satisfied with environmental requirements. Among several methods used for foundation constructions in cavity area, Rod Jet Pile(RJP) method has been widely used. While the RJP method was used to improve bearing capacity for the railway bridge foundations, water pollutions of drinking water as well as fishery located adjacent to this project area were occurred. The main reason of the water pollution was cement runoff used in cement mortar during injecting material in RJP method. Laboratory tests were performed to prevent water pollution. The compaction mortar method using low movable material was selected for this project. The quality of water at a fishery adjacent to the site and the compressive strength of cores taken from the construction site were measured. Test results show that the water pollutions was minimized, and the average compressive strength of foundation material was over 5 MPa. As a result of this study, compaction mortar method can be used to ensure the bearing capacity of foundation and to prevent environment pollutions.

The Effects of Road Geometry on the Injury Severity of Expressway Traffic Accident Depending on Weather Conditions (도로기하구조가 기상상태에 따라 고속도로 교통사고 심각도에 미치는 영향 분석)

  • Park, Su Jin;Kho, Seung-Young;Park, Ho-Chul
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.18 no.2
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    • pp.12-28
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    • 2019
  • Road geometry is one of the many factors that cause crashes, but the effect on traffic accident depends on weather conditions even under the same road geometry. This study identifies the variables affecting the crash severity by matching the highway accident data and weather data for 14 years from 2001 to 2014. A hierarchical ordered Logit model is used to reflect the effects of road geometry and weather condition interactions on crash severity, as well as the correlation between individual crashes in a region. Among the hierarchical models, we apply a random intercept model including interaction variables between road geometry and weather condition and a random coefficient model including regional weather characteristics as upper-level variables. As a result, it is confirmed that the effects of toll, ramp, downhill slope of 3% or more, and concrete barrier on the crash severity vary depending on weather conditions. It also shows that the combined effects of road geometry and weather conditions may not be linear depending on rainfall or snowfall levels. Finally, we suggest safety improvement measures based on the results of this study, which are expected to reduce the severity of traffic accidents in the future.

A Study on Development of Mobile LNG Yard Tractor Refueling Standards (이동식 LNG 야드트랙터 충전 기준 개발 연구)

  • Ryou, Young-don;Yu, Chul-hee;Koo, Bon-deuk;Lee, Dong-won
    • Journal of the Korean Institute of Gas
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    • v.22 no.6
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    • pp.59-64
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    • 2018
  • As part of measures to reduce fine dust, the government is promoting a project to convert the fuel of Yard Tractors(YT, tractors operated at ports), from diesel to LNG (Liquefied Natural Gas). While a port having a small number of yard tractors, it is not proper to construct a stationary LNG fueling station and supply LNG to YT due to a problem of BOG (Boil off gas) generation. Therefore, it is necessary to make a regulation and a standard on mobile LNG YT refueling station installation and inspection as an alternative. In this study, we have investigated domestic and foreign mobile LNG refueling cases and refueling standards, including the USA and Europe. In addition, we have suggested the risk reduction method according to the cause after investigation of the cause of LNG accidents. And last, based on the proposed risk reduction measures, we have proposed an amendment to the Regulation of the Urban Gas Business Law in Korea. The proposed mobile LNG YT refueling amendment of the Regulation includes ; maintenance of the safety distance from the protection facility, installation of an interlock device to prevent refueling in places other than the authorized place, installation of the identification system through biometrics, separation of the tank lorry and tow vehicle before refueling, checking the wheel fixed status of tank lorry before refueling, construction of the impounding area, safety measures before, during and after refueling, etc. The safety standards proposed in this study could be used as a reference in establishing standards for mobile LNG vehicle refueling in the near future.

A Study on Deep Learning-based Pedestrian Detection and Alarm System (딥러닝 기반의 보행자 탐지 및 경보 시스템 연구)

  • Kim, Jeong-Hwan;Shin, Yong-Hyeon
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.18 no.4
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    • pp.58-70
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    • 2019
  • In the case of a pedestrian traffic accident, it has a large-scale danger directly connected by a fatal accident at the time of the accident. The domestic ITS is not used for intelligent risk classification because it is used only for collecting traffic information despite of the construction of good quality traffic infrastructure. The CNN based pedestrian detection classification model, which is a major component of the proposed system, is implemented on an embedded system assuming that it is installed and operated in a restricted environment. A new model was created by improving YOLO's artificial neural network, and the real-time detection speed result of average accuracy 86.29% and 21.1 fps was shown with 20,000 iterative learning. And we constructed a protocol interworking scenario and implementation of a system that can connect with the ITS. If a pedestrian accident prevention system connected with ITS will be implemented through this study, it will help to reduce the cost of constructing a new infrastructure and reduce the incidence of traffic accidents for pedestrians, and we can also reduce the cost for system monitoring.

A Study on Construction of Collision Prevention Algorithm for Small Vessel Using WAVE Communication System (WAVE 통신을 활용한 소형선박의 충돌예방 알고리즘 구축에 관한 연구)

  • Lee, Myoung-ki;Park, Young-Soo;Kang, Won-Sik
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.25 no.1
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    • pp.1-8
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    • 2019
  • In December 2017, many collision accidents of small vessels, such as those between oil refineries and fishing boats, occurred near Yeonghung-do in Incheon. In order to prevent marine casualties from small vessels, the government is striving to improve the safety capabilities of ship operators by strengthening education and improving the working environment. They are providing education and refining training regulations for fishermen operating vessels under 5 tons. However, the situation includes certain vulnerabilities. In this study, we propose a collision prevention algorithm for small vessels using the Wireless Access in Vehicular Environments (WAVE) communication system, which is a new communication technique to prevent collisions with small ships. The collision avoidance algorithm used is based on DCPA/TCPA. Research analyses, simulation experiments and questionnaires have been conducted to define the criteria of DCPA/TCPA. As a result, the standard for DCPA was $8(L_a+L_b)$ and for TCPA was 2.5 min. Three different accident cases were selected, and this algorithm was applied to confirm alarm responses at certain times. This algorithm can provide information to the operators of small ships in advance to help them recognize potential collision situations.

A Study on the Guidelines for the Development of Domestic Flight Test Operation Manual (국내 비행시험 운영 매뉴얼 개발 기준 연구)

  • Kim, Mu-Geun;Baek, Seung-Don;Song, Chan-Yong;Ahn, Dae-Whee;Han, Jeongho;Yoo, Beong-Seon;Kang, Ja-Young
    • Journal of Advanced Navigation Technology
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    • v.23 no.4
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    • pp.281-288
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    • 2019
  • A Flight test is an important process that must be performed to maintain airworthiness in the aircraft lifecycle, including aircraft development and certification. Flight test can be conducted for the purpose of demonstrating or verifying compliance with the applicable standard. Results of the flight test air accident analysis confirm that it is caused by a combination of various factors as well as aircraft. The International Civil Aviation Organization recommends the establishment and implementation of a safety management system to prevent aircraft accidents, but it does not reflect the specificity of the flight test. As such, advanced countries are providing separate criteria to assist stakeholder in conducting flight test safety management. This study investigates and analyzes relevant regulations of advanced countries, in accordance with the construction of a national flight performance test site in Korea, and proposes government-level guidelines to help stakeholders develop their flight test operation manuals. The guidelines discuss topics such as organizational composition, safety and risk management, flight operation, personnel management, and administrative issues.

Estimation of installation spacing by analyzing the lateral behavior of the safety fence fixed to rail bottom (레일저부고정형 안전펜스의 횡 방향 거동 분석을 통한 설치간격 산정)

  • Park, Seonghyeon;Sung, Deokyong;Lee, Changho;Jung, Hyuksang;Youg, Seungkyong
    • Journal of The Korean Society For Urban Railway
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    • v.6 no.4
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    • pp.249-257
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    • 2018
  • The number of deaths for railway traffic accidents is mainly caused by working close to the track, or when unauthorized passage pass through the track. The safety fences are being used to ensure safety for workers close to the track, and to improve the efficiency of the work, without interfering with the passage of trains. However, a safety fence for railway tracks needs to be examined to see if it will interfere with the passage of trains. The purpose of this study is to analyze the safe distance between train and safety fence developed in Korea. In addition, the lateral load condition of wind pressure by trains is estimated and numerical analysis is carried out according to the installation intervals of railway safety fences. It has been confirmed that the proper spacing between the train and the railway safety fence should be at least 200 mm from the vehicle limit, and that the proper spacing of railway safety fence must be calculated in consideration of the wind pressure by trains.

Reserch On The Fundamental Technology To Utilization Of Platform To Providing Mobile Underground Geospatial Infomation Map (모바일용 지하공간통합지도 제공 플랫폼 활용을 위한 기반 기술 연구)

  • LEE, Tae-Hyung;KIM, Hyun-Woo
    • Journal of the Korean Association of Geographic Information Studies
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    • v.23 no.4
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    • pp.173-183
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    • 2020
  • In the midst of the aging of underground facilities in urban areas and anxiety about road excavation safety accidents, the Ministry of Land, Infrastructure and Transport began to build Underground Geospatial Infomation Map from 2015 as part of the 「ground subsidence prevention measures」 and efficient use of underground spaces. So, the scope is spreading every year. The current Underground Geospatial Infomation Map information is web-based and is operated in a desktop environment, so it is true that there are some limitations in its use in a field environment such as an excavation construction site. The Underground Geospatial Infomation Map, built and operated in a web-based environment, is a large-scale 3D data. Therefore, in order to service by transmitting data to the field without delay, it is necessary to lighten the Underground Geospatial Infomation Map data. In addition, the current Underground Geospatial Infomation Map is not unified in data formats such as 3DS and COLLADA, and the coordinate system method is also different in relative coordinates and absolute coordinates. In this study, by analyzing domestic and overseas prior research and technical use cases, a mobile Underground Geospatial Infomation Map data format and a lightweight method were presented, and a technology development was conducted to create a mobile underground space integration map in the presented format. In addition, the weight reduction rate was tested by applying 3D data compression technology so that data can be transmitted quickly in the field, and technology was developed that can be used by decompressing 3D data compressed in the field. finally, it aims to supplement the technology experimentally developed in this study and conduct additional research to produce it as software that can be used in the excavation site and use it.

A Study on the Evaluation of Expanded Metal Characteristics for Application Rockfall Facilities (낙석방지시설 적용을 위한 팽창메탈의 특성 연구)

  • Lee, Jong-In;Jung, Chun-Gyo;Kim, Sung-Ho;Hwang, Yeong-Cheol;Lee, Seung-Ho
    • Journal of the Korean GEO-environmental Society
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    • v.12 no.9
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    • pp.13-20
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    • 2011
  • There are many mountains in Korean Peninsula, and those used for the construction of roads and railways sectors are forming slopes. Slope collapse occurs with falling rocks and landslide because of the relaxation of the thawing rocks. The heavy rain in summer can also significantly contribute to the process, and abnormal climate change is much more influential than before. Therefore, rockfall-related accidents in rainy season are easily accessible in media every year. There has been a lot of research on application of strengthening compensation of the sections in order to minimize casualties and property damage. Rockfall Protection Net, however, has not been focused on much in the field yet. This study highlights the need of Rockfall Protection Net, since it can segregate the falling rocks inside the net relatively safely. Although there has been a little doubt about the effectiveness of rockfall protection facilities, it is obvious that relevant studies dealing with the solidity of the net are necessary for the rockfall protection net to be capable of supporting rockfall energies. As a result, Expanded metal strength is much more durable compared to the PVC coating net, and it is regarded as an excellent alternative material for the Rockfall Protection Net. In this study, the applicability of Expanded Metal as the alternative of Rockfall Protection Net is verified experimentally.

Identification of 19 Species of Poisonous Plants from Jeju Island and Construction of a Database Using DNA-barcoding (DNA-barcoding을 이용한 제주도 자생 독성 식물 19종의 종 식별 및 데이터베이스 구축)

  • Kwon, Eunchae;Kim, Joo-Young;Chang, Miwha;Lee, Minji;Moon, Seohyun;Lee, Won-Hae
    • Korean Journal of Plant Resources
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    • v.35 no.2
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    • pp.346-361
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    • 2022
  • Food poisoning accidents caused by poisonous plants occur every year. As certain poisonous plants are mistaken for edible plants causing food poisoning, accurate species identification of poisonous plants is required. DNA barcodes suitable for species identification of poisonous plants and database that can be used for accurate species identification are necessary for their use in forensic cases. In this study, species identification of 19 poisonous plants native to Jeju Island using seven DNA barcodes (trnH-psbA, trnL-trnF, trnL intron, rbcL, matK, ITS1-ITS4, 18S rRNA) was performed to construct a database containing sequence information and DNA barcode universality. trnL-trnF barcode and ITS1-ITS4 barcode were the easiest markers for PCR amplification and sequence retrieval, and the combination of the two barcodes enabled single species identification in 18 out of 19 plants. Therefore, when an investigation of unknown poisonous plants is requested, combination of trnL-trnF and ITS1-ITS4 barcodes is considered as a primary marker for species identification. The database of recommended DNA barcodes for each poisonous plant presented in this study will be helpful in plants poisoning cases.