• Title/Summary/Keyword: Cause of accident

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A Study on the Safety Distance of Benzene and Acrylonitrile Releases in Sccordance with Dike and Hole Size (벤젠 및 아크릴로나이트릴 누출시 방류벽 유무 및 누출공에 따른 피해 영향범위 산정에 관한 연구)

  • Kawg, Youngmin;Oak, Jaemin;Yoon, Sukyoung;Jung, Seungho
    • Journal of the Korean Institute of Gas
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    • v.22 no.1
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    • pp.18-25
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    • 2018
  • As the industries become more developed, the amounts of hazardous materials have been increased. Because of that, the possibility of accidents in plants is expected to increase. Especially, the dispersions of toxic materials cause serious effect to human life and environment, So it is very important to confirm safety distance of discharge accident. For this paper, we proposed new algorithms for toxic liquid, such as benzene and acrylonitrile. and using this argorithm, we are going to predict safety distance. The scenario of accidental release was assumed to be the release of entire quantity in 10 minutes is defined as worst-case scenario and Instantaneous release. Also the release from a partial rupture of line is used as an alternative case scenarios as NICS(National Institute of Chemical Safety) guidelines. Using ALOHA program and the algorithm for liquid toxic materials and suggested the graph, as well as correlated equations which can utilize emergency responders.

Clinical Observation and Treatment of Fracture-Dislocation of Talus (거골 골절 및 탈구의 임상적 고찰)

  • Lee, Dong-Chul;Kim, Se-Dong;Jung, Hae-Hoon
    • Journal of Yeungnam Medical Science
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    • v.9 no.2
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    • pp.302-311
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    • 1992
  • Talus is a important structure of the ankle joint and its function is critical for ambulation and weight bearing. The talus fracture is rare, but the complications of fracture and dislocation are serious and resulting in avascular necrosis, osteoarthritis. So its treatment is carefully considered at initial status. Authors reviewed 11 cases of fracture and dislocation of the talus treated at Yeungnam university hospital from 1984 to 1991. The longest follow up was 8 years and shortest, 1 year. The results were as follows. 1. There were all males, the average age was 30 years old. 2. The most common cause was fall down(8 cases), and next traffic accident(2cases), sports injury(1 case). 3. According to Marti-Weber classification, 1 cases was type I, 1 in type II, 4 in type III and 5 in type IV. 4. The method of treatment were open reduction and internal fixation in 6 cases, the others were closed reduction in 5 cases. 5. Final results(by Hawkins grading system) were as follows, 3 cases were excellent, 4 cases were good, 1 case was fair and 3 cases were poor. 6. Complications were AVN in 2 cases, degenerative arthritis in 8 cases, malunion in 1 case. 7. The range of motion of the ankle joint was relatively preserved(74%), but in the subtalar joint it was decreased(43%).

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Hemiarthroplasty in Comminuted Fracture and Dislocation of the Proximal Humerus (상완골 근위부 분쇄성 골절 및 탈구에서 시행한 견관절 반치환술)

  • Hwang Sung-Kwan;Kim Yong-Seok
    • Clinics in Shoulder and Elbow
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    • v.1 no.2
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    • pp.205-211
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    • 1998
  • The comminuted fracture and dislocation of the proximal humerus occur more frequently in older patient group and operative treatment is difficult due to poor bone quality. Based on Neer's work, hemiarthroplasty has now become widly accepted for the management of the three-part fracture and four-part fracture-dislocation of the proximal humerus in old age group. The purpose of this study is to evaluate function, pain relief, and patient satisfaction after hemiarthroplasty for proximal humerus fractures and dislocations. Authors reviewed and analyzed 14 prosthetic replacement in comminuted proximal humeral fracture and dislocation at the Department of Orthopaedic Surgery, Yonsei University Wonju College of Medicine from March, 1988 to May, 1997. The results were as follows the average age was 58.9years and the ratio of males and females was 5:9. The most common cause of injury was traffic accident(43%). According to the classification of Neer, three part fracture were three(21%), four-part fracture and four-part fracture-dislocation were eleven(79%). The prosthetic replacement was performed within two weeks in eight patient and six were performed after two weeks. The results were analysed according to Neer's criteria and five cases showed satisfactory results. We concluded that hemiarthroplasty for fracture and dislocation of the proximal humerus facilitated the restoration of humerus length and pain relief, thereby allowing earlier motion to prevent the development of painful shoulder: stiffness.

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A Study on the Sea-sickness Susceptibility of Seafarer at the Wheel House and Engine Room (조타실과 기관실 근무자의 뱃멀미 민감성에 대한 연구)

  • Kim, Deug-Bong;Kim, Bu-Gi;Rim, Geung-Su;Kim, Hong-Ryoel;Kim, Chang-Su
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.20 no.1
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    • pp.42-48
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    • 2014
  • Seasickness not only makes persons on board vessels to vomit but also causes vertigo, headache, sleepiness, fatigue, lethargy and other discomforts. This ailment leads to disturbance of biorhythm and decline of perception which would eventually cause reduction of situational awareness among ship's operators that leads to marine accident. This study is about the sensitivity of people onboard ships to seasickness and focused on deck or navigation officer cadets(apprentice officers) and engine officer cadets(apprentice engineers) who have no previous experiences on board. It is conducted by using motion sensor that can measure ship's X, Y, Z-axis motions and through the questionnaire survey, and evaluated each students' degree of seasickness symptoms. Through this study, in same circumstance, we have known that there are different degrees of motion sickness for wheel house worker and engine room worker, It also confirmed that seasickness have high relationship with degree of hull motion and also, with cycle of hull motion. In addition, we have confirmed that Z-axis hull movement has higher relationship with seasickness than X-axis and Y-axis hull movements. This study aims to initiate additional researches about X-axis and Y-axis of the ship's motion which it expects to greatly enhance safety of wheelhouse and engine room personnel, ship's livability and comfortable sailing.

A Case Study on the Human Error Analysis of Forklift Operations in a Small Enterprise (소규모 사업장의 지게차 작업에 관한 휴먼에러 분석 사례 연구)

  • Ha, Gyu Cheol;Park, Jungchul
    • Journal of the Korea Convergence Society
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    • v.12 no.5
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    • pp.207-215
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    • 2021
  • A forklift is an industrial vehicle with a power-operated fork for lifting and moving heavy loads over short distances. A significant number of accidents are caused by forklifts every year. Most of them are known to be caused by the unsafe acts of workers. However, only a few studies have focused on the risks of forklift work from the perspective of human error. In addition, various methods have been developed to analyze the risk of human error, while it is hard to find studies that directly compare the effectiveness or strengths/weaknesses of those methods. This study aims to analyze risk factors related to unsafe behavior in forklift operations using two representative human error analysis techniques, i.e., .SHERPA and HE-HAZOP, and compare their advantages and disadvantages. The analysis was performed on three main forklift operations ('unloading from the truck', 'moving and loading into the storage', and 'loading on the truck'). As a result, 118 errors and 34 remedial measures were derived by SHERPA. Through HAZOP, 139 errors and 54 measures were derived. The two techniques were compared in terms of the number of results and the method of deriving errors and remedial measures, cause analysis, and risk assessment. This study might be used to reduce human error related disasters in workplaces using forklifts. In order to provide a guide for choosing an appropriate analysis method, more comparative studies on different techniques involving wide range of tasks are needed in the future.

A Method of Developing a Ground Layer with Risk of Ground Subsidence based on the 3D Ground Modeling (3차원 지반모델링 기반의 지반함몰 위험 지반 레이어 개발 방법)

  • Kang, Junggoo;Kang, Jaemo;Parh, Junhwan;Mun, Duhwan
    • Journal of the Korean GEO-environmental Society
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    • v.22 no.12
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    • pp.33-40
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    • 2021
  • The deterioration of underground facilities, disturbance of the ground due to underground development activities, and changes in ground water can cause ground subsidence accidents in the urban areas. The investigation on the geotechnical and hydraulic factors affecting the ground subsidence accident is very significant to predict the ground subsidence risk in advance. In this study, an analysis DB was constructed through 3D ground modeling to utilize the currently operating geotechnical survey information DB and ground water behavior information for risk prediction. Additionally, using these results, the relationship between the actual ground subsidence occurrence history and ground conditions and ground water level changes was confirmed. Furthermore, the methodology used to visualize the risk of ground subsidence was presented by reconstructing the engineering characteristics of the soil presented according to the Unified Soil Classification System (USCS) in the existing geotechnical survey information into the internal erosion sensitivity of the soil, Based on the result, it was confirmed that the ground in the area where the ground subsidence occurred consists of more than 40% of sand (SM, SC, SP, SW) vulnerable to internal erosion. In addition, the effect of the occurrence frequency of ground subsidence due to the change in ground water level is also confirmed.

A Comparison Study of Model Reduction Method with Direct Impact Analysis of Truck-column Collision (모델축소법을 이용한 교각-차량 충돌변위 예측 및 직접충돌해석법과의 비교연구)

  • Lee, Jaeha;Kim, Kyeongjin;Jeong, Yoseok;Kim, Wooseok
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.28 no.6
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    • pp.675-682
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    • 2015
  • Current design codes such as AASHTO LRFD or Korean Highway Bridge Design Code recommend of using static force for designing bridge column against vehicle collisions. However, there was an accident that the bridge was collapsed shortly after vehicle impact on bridge pier in Nebraska(near Big Spring, 2003). It was found that the second largest cause of bridge collapse is collision after hydraulic causes. It can be thought that the possibility of truck-bridge collision are getting increasing as the size of truck increases and traffic condition are becoming improved. However, dynamic behavior under the impact loading seldom considered in bridge design procedure due to computational cost and time. In this study, in order to reduce the computational cost for dynamic impact analysis, model reduction method was developed. Obtained results of residual displacement were compared with the results of direct impact simulations.

An Analytical Study of the Effect of Inclined Angle of Road on Turn-over Accident of a High-speed Coach running on a Curved Road under Cross-wind Condition (횡풍이 작용하는 속도로의 회전구간에서 도로의 편경사각이 주행차량의 전복사고에 미치는 영향에 관한 분석연구)

  • Park, Hyeong-Su
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.1
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    • pp.373-381
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    • 2017
  • Kyeonggi Provincial Government is considering double decker bus service to solve the problem of heavy rush hour traffic. However, the height-to-width ratio is more than 1.16 times larger than that of a general high-speed single decker bus, and the center of gravity is higher. This could cause driving stability problems, such as turnover and breakaway from the lane, especially under strong side-wind conditions at high speed. In this numerical study, the driving characteristics of a model double decker bus were reviewed under side-wind and superelevation conditions at high driving speed. The rolling, pitching, and yawing moment of the model bus were calculated with CFD numerical simulation, and the results were compared to the recovery angular moments of the model bus to evaluate the dynamic stability under given driving conditions. As the model vehicle moves on a straight level road, it is stable under any side-wind conditions. However, on a curved road under side-wind conditions, it could reach unstable conditions dynamically. There is a chance that the bus will turn over when it moves on a curved road with a radius of gyration less than 100 m under side-wind (15 m/s). However, there is a very small chance of breakaway from the lane under any driving conditions.

Analyzing drivers' visual response variation in very long expressway tunnel ; the Yuksimnyeong tunnel (장대터널에서의 운전자 시각각성변화 분석연구 (육십령터널을 대상으로))

  • Kim, Ju-Yeong;Kim, Hyeon-Jin;Jang, Myeong-Sun
    • Journal of Korean Society of Transportation
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    • v.27 no.1
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    • pp.17-25
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    • 2009
  • This research analyzed the changes of drivers' visual workload with beta wave of bionic signals from brain's occipital lobe from entrance to exit section of the Yuksimnyeong tunnel which is 3.1km long in Daejeon-Tongyeong section of Jungbu expressway. There are 10 subjects who Participate our experiments and the results are as follows. First. the drivers' visual workload is higher about 41% in entrance section of the tunnel than 200m in advance of the section of the tunnel. Second, it is higher than 200m in advance of the section of the tunnel by 34.5% that the value of the drivers' visual workload who is driving in the tunnel. Third, as a result of analyzing the tunnel into 200m unit section, it is statistically different from other sections' at the 1.0km and 2.4km section from the entrance of the tunnel. If drivers sustain average visual workload for safe driving in very long tunnel, it's not desirable environment that drivers' visual workload goes under the average workload. Therefore, it would be the section where drivers who is driving in tunnel could cause a traffic accident.

Development of an Underwater Rope-cutter Device and Controller for Removal of Propeller and Shaft Foreign Material for Small Vessel (소형선박용 프로펠러 및 샤프트 이물질 제거를 위한 수중절단기 기구 설계 및 제어기 개발)

  • Lee, Hunseok;Oh, Jin-Seok;Choi, Sun-Hong
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.25 no.7
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    • pp.927-935
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    • 2019
  • Screw-failure accidents in small ships frequently occur in coastal waters. In particular, vessels' propulsion systems are frequently coiled due to objects such as fish-nets and ropes that float on the sea. The failure of the ship's propulsion system can cause primary accidents such as ship operation delays and drifting due to loss of power; furthermore, the possibility of secondary accidents such as those involving operators in the underwater removal of rope stuck in a propeller. Ships that do not have the proper tools to solve these problems must be either lifted onto land to be repaired or divers must dive directly under the ship to solve the problem. Accordingly, some small vessels have been equipped with rope-cutter devices on the propeller shaft to prevent ship propeller system accidents in recent years; however, they are not being applied efficiently due to the cost and time of installation. To solve these problems, this study develops an underwater rope-cutter device and controller for the removal of propeller and shaft foreign material in small vessels. This device has simple structures that use the principle of a saw. Meteor gears and crank pins were used for the straight-line rotation of saw blades of the underwater rope-cutters to allow for long strokes. Furthermore, the underwater rope-cutting machines can be operated by being connected to the ship battery. The user, a non-professional, can ensure convenience and stability by applying reverse current prevention and a speed control circuit so that it can be used more conveniently and safely.