• Title/Summary/Keyword: Traffic Accidents

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A CFD Study of Oil Spill Velocity from Hole in the Hull of Oil Tanker (유조선 선체 파공에 따른 원유 유출 유속의 CFD 연구)

  • Choi, Dooyoung;Lee, Jungseop;Paik, Joongcheol
    • Proceedings of the Korea Water Resources Association Conference
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    • 2018.05a
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    • pp.71-71
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    • 2018
  • Sea pollution accidents have been occurred due to the increase of marine ship traffic. Oil spill from the hull hole induced by tanker collision results in the huge sea pollution. Proper and prompt reaction on such oil spill disaster is needed to minimize the damage. Thru-hull emergency wood plug is typically used to manually close small holes, while it is required to develop some mechanical devices for closing large holes in the hull due to huge fluid pressure. Accurate estimation of oil discharge and velocity from such holes are important to develop proper device to control hull hole damage. High resolution CFD modeling investigation on the configurations of hull hole of 7.5 m initial depth and 30 cm diameter, which was observed in the oil spill accident of the Hebei Sprit off the west coast of Korea in 2007, has been carried out to compute the oil spill velocity distribution in terms of flow depth. Friction loss due to the viscous flow and the discharge coefficient of crude oil with specific gravity SG = 0.85 and viscosity of $4-12cP(mPa{\cdot}s)$ at the temperature of $20^{\circ}C-100^{\circ}C$ are presented in terms of Reynolds number based on the results of high-resolution CFD modeling.

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Audiological Study in Hearing Impaired Patient with Non-Perforated Ear Drums (고막천공 없이 자각난청을 호소하는 환자의 순음청력상 관한 임상통계적 고찰)

  • 김은우;장병일;추광철;김선곤
    • Proceedings of the KOR-BRONCHOESO Conference
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    • 1976.06a
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    • pp.86.2-86
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    • 1976
  • Authors have performed the audiological analysis in accordance with age, sex, site, duration, cause, ear drums, curve pattern, and hearing level taken from 165 patients (Male; 101, Female; 64) with non-perforated ear drums who had complained hearing impairment. The results are as follows. 1. The audiographic pattern has classified into Normal (30 cases, 18.18%), Flat form (46 cases, 20.6%), Ascending form (5 cases, 3%), Mountain form (9 cases, 5.4%), Basin form (7 cases, 4.2%), Total deaf (24 cases, 14.55%) and Others (10 cases, 6%). 2. In age distribution, the highest is in 3rd decade (50 cases, 30.3%), and the next is in 2nd (43 cases, 26%), 4th (27 cases, 16.3%) in order. 3. Male (101 cases) is more than female (64 cases) giving ratio of 1.9 : 1 4. Bilateral involvement is in 58 cases and unilateral is in 77 5. 45 cases (27.3%) in duration of hearing loss is as short as 3 months and the next is overs; 28 cases (16.9%) 6 to 10 years; 21 cases (12. 7%). And in cases of total deaf, nearly all cases is over 10 years. 6. The suspected cause of the hearing loss is unknown (99 cases, 60%) and the next is following head trauma by traffic accidents in 31 cases (18.8 %) and is related to the middle ear diseased in 12. cases (7.3%). Other causes like senile, noise etc. are in few. 7. The most common findings in ear drums is normal in 177 ears (79.4%) and the next is retracted drums in 28 ears (12.6%). 8. The average hearing level is widely distributed from mild to profound hearing loss which was not related to the audigraphic pattern.

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Analysis of Intercepted Flow according to Change of Flow Width in Gutter (도로 흐름폭 변화에 따른 차집유량 분석)

  • Joo, Dong Won;Kim, Jung Soo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.41 no.4
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    • pp.377-386
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    • 2021
  • In dense cities, which are covered by many impermeable areas, rainwater flows quickly along the roads and collects in certain areas. The surface runoff that fails to get intercepted by the roadside rain gutters results in a wider flow of water along the sides, which in turn increases the amount of water on the road and causes traffic congestion as well as accidents due to slippage. Based on these issues, this study was carried out in order to propose an intercepted flow calculation formula. To this end, the maximum longitudinal slopes of arterial roads and expressways were reflected to depict a road condition of 2~10 %, while a general traverse slope of 2 % was selected for the traverse slope on the side. As for the road lane condition, two, three, and four lanes were chosen for the area from the centerline to the sidewalk. As for the experimental flow rate, the rainwater runoffs at the actual design frequency of 5, 10, 20, and 30 years for road conditions were converted into experimental flow rates, and as a result, flow rates ranging from 1.36 l/s to 3.96 l/s were divided into ten flow rates for a hydraulic experiment. Also, an equation taking into consideration the inflow velocity and flow width along the roadsides was proposed. The results of the experiment showed an increase in flow width and a decrease in interception rate. Also, the inflow velocity at a traverse slope of 2 % was measured, while increasing the longitudinal slope. Accordingly, an equation for calculating the flow intercepted by rain gutters at a flow width reflecting the longitudinal slope of the road and rainwater runoff, according to the design frequency, was derived by performing a regression analysis using IBM SPSS Statistics 24. It is deemed that the equation derived in this study will be useful in designing rain gutters for roads.

Spatial Econometrics Analysis of Fire Occurrence According to Type of Facilities (시설물 유형에 따른 화재 발생의 공간 계량 분석)

  • Seo, Min Song;Yoo, Hwan Hee
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.37 no.3
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    • pp.129-141
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    • 2019
  • In recent years, fast growing cities in Korea are showing signs of being vulnerable to more disasters as their population and facilities increase and intensify. In particular, fire is one of the most common disasters in Korea's cities, along with traffic accidents. Therefore, in this study, we analyze what type of factors affect the fire that threatens urban people. Fire data were acquired for 10 years, from 2007 to 2017, in Jinju, Korea. Spatial distribution pattern of fire occurrence in Jinju was assessed through the spatial autocorrelation analysis. First, spatial autocorrelation analysis was carried out to grasp the spatial distribution pattern of fire occurrence in Jinju city. In addition, correlation and multiple regression analysis were used to confirm spatial dependency and abnormality among factors. Based on this, OLS (Ordinary Least Square) regression analysis was performed using space weighting considering fire location and spatial location of each facility. As a result, First, LISA (Local Indicator of Spatial Association) analysis of the occurrence of fire in Jinju shows that the most central commercial area are fire department, industrial area, and residential area. Second, the OLS regression model was analyzed by applying spatial weighting, focusing on the most derived factors of multiple regression analysis, by integrating population and social variables and physical variables. As a result, the second kind of neighborhood living facility showed the highest correlation with the fire occurrence, followed by the following in the order of single house, sales facility, first type of neighborhood living facility, and number of households. The results of this study are expected to be useful for analyzing the fire occurrence factors of each facility in urban areas and establishing fire safety measures.

An Empirical Study on Firefighters' Health Hazard Factors -Focused on Fire Fighters, Rescue Workers and Emergency Medical Technicians Perception in Busan Fire Fighters- (소방공무원 건강장해 유해인자에 대한 실증연구 -화재진압대원, 구조대원, 구급대원의 인식조사를 중심으로-)

  • Kwon, Seol A;Lee, Min-Kyu;Park, Sang Ho;Kim, Da Young;Ryu, Sang Il
    • The Journal of the Korea Contents Association
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    • v.19 no.3
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    • pp.520-529
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    • 2019
  • This study is intended to provide basic data for health management of firefighters in the future by empirically looking into health hazard factors of firefighters in Busan City. It was revealed that firstly, the danger of harmful chemicals in a fire was perceived the most by firefighters, who extinguish a fire in person on the scene of a fire, and it was followed by the danger of falling while putting out a fire. This study is intended to provide basic data for health management of firefighters in the future by empirically looking into health hazard factors of firefighters in Busan City. It was revealed that firstly, the danger of harmful chemicals in a fire was perceived the most by firefighters, who extinguish a fire in person on the scene of a fire, and it was followed by the danger of falling while putting out a fire. Moreover, the danger of shift work was perceived the most by paramedics. This corresponds to the existing studies arguing that shift work is harmful to health. Next, the overload of patient transport was recognized as the second biggest hazard factor. This demonstrates they are worried about various second accidents that may happen due to a lot of patient transport works. In addition, the possibility of causing a traffic accident was perceived as a hazard factor too, since they must drive ambulance cars quickly to transport patients. Lastly, rescue workers regarded these hazard factors to be most dangerous. This is associated with their occupational characteristics, because rescue workers are the closest to diverse risks including a fire.

A Study on the Efficiency Evaluation of the Improvement Project for School Zone Using DEA (DEA를 활용한 어린이보호구역개선사업의 효율성 평가에 관한 연구)

  • Kang, Myung Sik;Kang, Tae Euk;Ju, Jung Hee
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.38 no.6
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    • pp.895-906
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    • 2018
  • The improvement project for school zone in Korea is occurring mostly in kindergartens and elementary schools in which children are mainly active, and is being promoted as part of measures to prevent children's traffic accidents. However, since the study on the essential installation facilities and proper level of safety facilities for School zone is lacking, this study relatively evaluated the efficiency of safety facility installation using DEA (Data Envelope Analysis) and suggested improvement plan. We built the facilities and incident data for 28 school zones in Hwaseong City. Six major facilities (Raised intersection, Raised crosswalk, Protective fence, Skid Proof, Speed hump, Speed cameras) that have proven to be effective in the preceding research were analyzed as input factors. As a result of the analysis, only 12 out of 28 showed efficiency and 16 out of efficiency. Effective groups of school zones were found to have fewer installed Protective fences, Skid Proof, and Speed cameras installations than school zones classified as ineffective groups. Protective fences were found to be efficient even if only 47% of the total extension of the school zone was installed, and the number of slip prevention facilities was 8.7 per square km. The number of subjects to be compared is 28, so this study is limited to use as a relative efficiency evaluation index, and it can be grouped into nationwide units and efficiency evaluation can be done for each group.

A Study on Road Safety Evaluation Method for Improvement Project of Two-Lane Road (2차로 시설개량 사업의 도로 안전성 평가방법 연구)

  • Shin, Chul-Ho;Kim, Nakseok
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.39 no.1
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    • pp.105-114
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    • 2019
  • Recently, the paradigm of road policy has been focused on user safety. Recently, the number of road facility improvement project has been continuously increased but the economic feasibility (B/C ratio) is insufficient. Therefore, it is necessary to select a reasonable road improvement project through accurate and objective analysis of the road safety evaluation. In this study, to develop a new road safety evaluation method, data were collected based on the current road safety evaluation method for 75 routes including national roads and provincial ones. Based on the collected data, problems were analyzed and utilized as the basic factors of the new road safety evaluation method. Therefore, in this study, traffic accidents were reflected as a general evaluation item by weighing to solve these problems, and the evaluation items were added from experiences and ideas of the local public officials. For each evaluation item, a reasonable weight was determined through AHP (Analytic Hierarchy Process) questionnaire evaluation with highway experts. In addition, the safety index was determined based on the evaluation criteria for each evaluation item. The criteria for evaluating the danger zone are determined by the overall safety index. Finally, the criteria for selection of road improvement projects based on the overall risk level were derived.

A study on School Safety Policies by an Needs Analysis (요구분석을 통한 학교안전정책 개선방안 연구)

  • Oh, Dae-Young;Shin, Seon-Hi;Park, Youn-Ju;Kim, Kyung-Hwoi;Han, Jong-Guk
    • The Journal of Sustainable Design and Educational Environment Research
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    • v.18 no.2
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    • pp.22-34
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    • 2019
  • The purpose of this study was two-fold. Firstly, it investigated the current state of the 34 specific policies of school safety-accident prevention that were implemented at K-12 public schools in accordance with the $1^{st}$ School Safety-Accident Prevention Plan established in December 2015. Secondly, it prioritized the policies based on the outcomes from the investigation to make policy recommendations for future improvement. For this purpose, we surveyed 614 school teachers and staff from 24 school-safety research schools across the nation on their perception of the current policies for preventing school safety accidents. Specifically, they were asked about the degree of realization and the necessity of expansion of the policies. Based on the survey results, the Borich index as a needs measure was computed for each policy and a list of policies prioritized in descending order of the index was presented. The results of the study showed that school teachers and staff's perception of the improvement of school safety since the policies took effect was highly positive in general. It was also shown that the policies perceived as best-implemented were, in descending order, "first-aid education for teachers and staff", "safety management of school meals", "prevention activity of student traffic safety-accident", and so on. The majority of survey respondents said that the policies were being implemented well and that they should be expanded and enhanced. As a result of the Borich's needs analysis, it was found that "more collegial collaboration between the Office of Education and other relevant organizations in the community for school safety", "prevention education activity for water safety", and so forth should be more actively implemented.

A Review on Clinical Research Trends in the Treatment of Post Traumatic Stress Disorder (PTSD) in Korean Medicine (외상후 스트레스장애 치료에 대한 한의학 임상연구 동향)

  • Joo, Sungjun;Kwon, JungEun;Kwon, Chan-Young;Lee, Boram;Kim, Sang-ho
    • Journal of Oriental Neuropsychiatry
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    • v.30 no.3
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    • pp.251-263
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    • 2019
  • Objectives: The purpose of this study was to review the clinical research trends in the treatment of post traumatic stress disorder (PTSD) in Korean medicine (KM). Methods: We searched MEDLINE, CENTRAL, EMBASE, Google Scholar and five Korean databases through May 2019, for studies on KM to treat PTSD. Clinical research that conducted KM treatment of PTSD patients were included. Two researchers independently conducted study selection and data extraction process. Results: Totally, eight studies were included in this review. Types of traumatic events that patients experienced included physical violence/threatening, traffic accidents, sexual violence and personal tragic events. KM interventions performed included acupuncture, moxibustion, herbal medicine, physical therapy, and KM-based psychotherapy. Treatment duration varied from two days to more than five months. Follow-up began at least one week to three months after the end of treatments. It was reported that the major psychological and/or somatic symptoms of PTSD, such as anxiety, depression, insomnia, and musculoskeletal pain, subjectively improved, as well as other objective outcomes: Impact Event Scale-Revised Korean version (IES-R-K), Beck's Depression Inventory (BDI), State-Trait Anxiety Inventory, Hwabyung Symptoms/characters, Electroencephalography (EEG) change, etc. Statistical studies were conducted in three studies only. Outcomes such as Visual Analogue Scale (VAS), BDI, and IES-R-K showed statistically significant improvement after KM treatments. There was no study reporting adverse events during or after the interventions. Conclusions: According to this review, diverse types of KM treatments have been used among PTSD patients in eight studies. The KM treatments effectively improved psychological and somatic symptoms of PTSD patients. However, the lack of high quality research as well as the lack of standardization of KM treatments for PTSD are limitations. Further methodologically robust clinical trials should be performed, and the standardization of KM treatments for PTSD should be sought.

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.