• Title/Summary/Keyword: accident rate model

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Evaluation of Damage Range Variation Based on Operation System of Chlorine Facility in Water Purification Plant using KORA (KORA를 활용한 정수장 염소 취급시설의 운영조건에 따른 피해범위 변화 평가)

  • Kwak, Sollim;Lim, Hyeongjun;Ryu, Taekwon;Choi, Woosoo;Jung, Jinhee;Lee, Jieun;Kim, Jungkon;Lee, Yeonhee;Ryu, Jisung;Yoon, Junheon;Yoon, Yi;Lee, Jinseon
    • Journal of the Korean Institute of Gas
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    • v.22 no.3
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    • pp.84-90
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    • 2018
  • We researched the way to minimize the damage when the chlorine-leak accident take place in a purification plant. Since the level of risk based on the Off-site Risk Assessment(ORA) is a combination of proportional to the number of residents in the damaged area and frequency of accidents, we suggested the adequate conditions to reduce the number of residents in the damaged area by means of the operating temperature of a handling facility, installation of a emergency shut-off valve, and the analysis of the variation of the damaging range in accordance with the type of enclosure. The coverage of damage was calculated by the 'KORA(Korea Off-site Risk Assessment Supporting Tool) program. The research shows that the lower operating temperature gets, the more emergency shut-off valve being installed and the higher enclosure level of facility becomes, the extent of damage gets decreased. The decreasing rate of worst case was 17.6%, 71%, 34.5% respectively, the decreasing rate of alternative case was 31.6%, 69.0%, 34.8% respectively.

A Study on the Ship's Speed Control and Ship Handling at Myeongnayang Waterway (명량수도 해역에서 항해속력 규제와 선박운용에 관한 연구)

  • Kim, Deug-Bong;Jeong, Jae-Yong;Park, Young-Soo
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.20 no.2
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    • pp.193-201
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    • 2014
  • This study provided safe sailing speed and appropriate passing time to areas of known strong current water to prevent marine accident of the ships. To the interpretation of these data which target Myeongnyang waterway, AIS data of the ship was collected from $12^{th}$ July to $15^{th}$ July 2010 and site environment was investigated on $4^{th}$ September 2010. On the basis of the collected data, the 'Minimum Navigation Speed' and 'Optimum Navigation Speed' were calculated. It has also considered the 'Spare control force' or allowance and the 'Respond Rudder Angle' for each tidal current speed. Additionally, it suggested the safe passing time to strong current area by analyzing tidal level and tidal current speed. The conclusion of the research are as follows : (1) If the flow rate is greater than 4.4 kn, it is difficult for the model ship to control herself by her own steering power and to cope with tidal current pressure force and yaw moment caused by the tidal current.. (2) The minimum navigation speed should be over 2.3 times the tidal current and the optimum navigation speed should be over 4.0 times the tidal current. (3) When spring tide, the optimum passing time at Myeongnyang waterway is between 30 minutes to 1 hour before the time of high/low water, and at 5 hours after high/low water, passing of ships should be avoided because it is time when the flow rate is over 4 kn.

The Effectiveness of WBI(Web-Based Instruction) on the Knowledge and Attitude of Traffic Safety among Middle School Students (웹기반 교육이 중학생의 교통안전 지식과 태도에 미치는 효과 연구)

  • 장시원;이명선
    • Korean Journal of Health Education and Promotion
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    • v.21 no.3
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    • pp.101-116
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    • 2004
  • Korea has the highest traffic accident occurrence rate in the world. It means that we are forced to face a tremendous amount of economic loses and great cost of life. Even though this phenomenon consistently has arose as a public issue every year and many researchers have emphasized the importance of safety education as the fundamental solution, we are still trying to make a long-lasting and effective traffic safety education programs for children and adolescents. The purpose of this study was to test the effectiveness of web-based learning for traffic safety in Korea middle school. For this purpose, the instructive model was constructed based on the ASSURE model and a special web-site of education was developed on behalf of practical use of multi-media learning materials for the traffic safety. The research subject was represented by 259 students from second grade in 2 middle schools located in Seoul Korea. The traffic safety education program using web-site was preceded to the 136 students as a case group for 45 minutes total 3 times. Other 126 students are control group those who did not get with this program. The survey was conducted before and after the education. The results of this study were as follow: 1. The knowledge analysis from the comparison between before and after of the lesson showed case group and control group scored average at 11.25 points and 10.97 points. However, after they attended programs, case group scored 13.57 points and control group scored 10.85 points. The difference from the result of the case group was statistically significant(p<0.001). 2. The attitude analysis from the comparison between before and after of the lesson showed case group and control group scored averages at 29.59 points and 28.21 points. However, after they attended program, case group scored 37.23 points and control group scored 32.71 points. The difference from the result of the case group was statistically significant(p<0.05). 3. Regarding the domain analysis by means of web-based traffic safety education, only the case group had a statistically significant score in the case of knowledge 'safe utilization of bicycle' and 'The Characteristic of Automobile and Safer Mode of Walking for Pedestrian'(p<0.01, p< 0.001), and in the case of attitude 'safe walking and crossing' 'The Characteristic of Automobile and Safer Mode of Walking for Pedestrian'(p<0.01, p<0.001). 4. Web based instruction for traffic safety was effective in terms of improving students' knowledge and attitude for traffic safety.

A Study on the Analysis Effect Factors of Illegal Parking Using Data Mining Techniques (데이터마이닝 기법을 활용한 불법주차 영향요인 분석)

  • Lee, Chang-Hee;Kim, Myung-Soo;Seo, So-Min
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.13 no.4
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    • pp.63-72
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    • 2014
  • With the rapid development in the economy and other fields as well, the standard of living in South Korea has been improved, and consequently, the demand of automobiles has quickly increased. It leads to various traffic issues such as traffic congestion, traffic accident, and parking problem. In particular, this illegal parking caused by the increase in the number of automobiles has been considered one of the main reasons to bring about traffic congestion as intensifying any dispute between neighbors in relation to a parking space, which has been also coming to the fore as a social issue. Therefore, this study looked into Daejeon Metropolitan City, the city that is understood to have the highest automobile sharing rate in South Korea but with relatively few cases of illegal parking crackdowns. In order to investigate the theoretical problems of the illegal parking, this study conducted a decision-making tree model-based Exhaustive CHAID analysis to figure out not only what makes drivers park illegally when they try to park vehicles but also those factors that would tempt the drivers into the illegal parking. The study, then, comes up with solutions to the problem. According to the analysis, in terms of the influential factors that encourage the drivers to park at some illegal areas, it was learned that these factors, the distance, a driver's experience of getting caught, the occupation and the use time in order, have an effect on the drivers' deciding to park illegally. After working on the prediction model, four nodes were finally extracted. Given the analysis result, as a solution to the illegal parking, it is necessary to establish public parking lots additionally and first secure the parking space for the vehicles used for living and working, and to activate the campaign for enhancing illegal parking crackdown and encouraging civic consciousness.

Intelligent Optimal Route Planning Based on Context Awareness (상황인식 기반 지능형 최적 경로계획)

  • Lee, Hyun-Jung;Chang, Yong-Sik
    • Asia pacific journal of information systems
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    • v.19 no.2
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    • pp.117-137
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    • 2009
  • Recently, intelligent traffic information systems have enabled people to forecast traffic conditions before hitting the road. These convenient systems operate on the basis of data reflecting current road and traffic conditions as well as distance-based data between locations. Thanks to the rapid development of ubiquitous computing, tremendous context data have become readily available making vehicle route planning easier than ever. Previous research in relation to optimization of vehicle route planning merely focused on finding the optimal distance between locations. Contexts reflecting the road and traffic conditions were then not seriously treated as a way to resolve the optimal routing problems based on distance-based route planning, because this kind of information does not have much significant impact on traffic routing until a a complex traffic situation arises. Further, it was also not easy to take into full account the traffic contexts for resolving optimal routing problems because predicting the dynamic traffic situations was regarded a daunting task. However, with rapid increase in traffic complexity the importance of developing contexts reflecting data related to moving costs has emerged. Hence, this research proposes a framework designed to resolve an optimal route planning problem by taking full account of additional moving cost such as road traffic cost and weather cost, among others. Recent technological development particularly in the ubiquitous computing environment has facilitated the collection of such data. This framework is based on the contexts of time, traffic, and environment, which addresses the following issues. First, we clarify and classify the diverse contexts that affect a vehicle's velocity and estimates the optimization of moving cost based on dynamic programming that accounts for the context cost according to the variance of contexts. Second, the velocity reduction rate is applied to find the optimal route (shortest path) using the context data on the current traffic condition. The velocity reduction rate infers to the degree of possible velocity including moving vehicles' considerable road and traffic contexts, indicating the statistical or experimental data. Knowledge generated in this papercan be referenced by several organizations which deal with road and traffic data. Third, in experimentation, we evaluate the effectiveness of the proposed context-based optimal route (shortest path) between locations by comparing it to the previously used distance-based shortest path. A vehicles' optimal route might change due to its diverse velocity caused by unexpected but potential dynamic situations depending on the road condition. This study includes such context variables as 'road congestion', 'work', 'accident', and 'weather' which can alter the traffic condition. The contexts can affect moving vehicle's velocity on the road. Since these context variables except for 'weather' are related to road conditions, relevant data were provided by the Korea Expressway Corporation. The 'weather'-related data were attained from the Korea Meteorological Administration. The aware contexts are classified contexts causing reduction of vehicles' velocity which determines the velocity reduction rate. To find the optimal route (shortest path), we introduced the velocity reduction rate in the context for calculating a vehicle's velocity reflecting composite contexts when one event synchronizes with another. We then proposed a context-based optimal route (shortest path) algorithm based on the dynamic programming. The algorithm is composed of three steps. In the first initialization step, departure and destination locations are given, and the path step is initialized as 0. In the second step, moving costs including composite contexts into account between locations on path are estimated using the velocity reduction rate by context as increasing path steps. In the third step, the optimal route (shortest path) is retrieved through back-tracking. In the provided research model, we designed a framework to account for context awareness, moving cost estimation (taking both composite and single contexts into account), and optimal route (shortest path) algorithm (based on dynamic programming). Through illustrative experimentation using the Wilcoxon signed rank test, we proved that context-based route planning is much more effective than distance-based route planning., In addition, we found that the optimal solution (shortest paths) through the distance-based route planning might not be optimized in real situation because road condition is very dynamic and unpredictable while affecting most vehicles' moving costs. For further study, while more information is needed for a more accurate estimation of moving vehicles' costs, this study still stands viable in the applications to reduce moving costs by effective route planning. For instance, it could be applied to deliverers' decision making to enhance their decision satisfaction when they meet unpredictable dynamic situations in moving vehicles on the road. Overall, we conclude that taking into account the contexts as a part of costs is a meaningful and sensible approach to in resolving the optimal route problem.

Assessment factors for the Selection of Priority Soil Contaminants based on the Comparative Analysis of Chemical Ranking and Scoring Systems (국내.외 Chemical Ranking and Scoring 체계 비교분석을 통한 우선순위 토양오염물질 선정을 위한 평가인자 도출)

  • An, Youn-Joo;Jeong, Seung-Woo;Kim, Tae-Seung;Lee, Woo-Mi;Nam, Sun-Hwa;Baek, Yong-Wook
    • Journal of Soil and Groundwater Environment
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    • v.13 no.6
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    • pp.62-71
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    • 2008
  • Soil quality standards (SQS) are necessary to protect the human health and soil biota from the exposure to soil pollutants. The current SQS in Korea contain only sixteen substances, and it is scheduled to expand the number of substances. Chemical ranking and scoring (CRS) system is very effective to screen the priority chemicals for the future SQS in terms of their toxicity and exposure potential. In this study, several CRS systems were extensively compared to propose the assessment factors that required for the screening of soil pollutants The CRS systems considered in this study include the CHEMS-1 (Chemical Hazard Evaluation for Management Strategies), SCRAM (Scoring and Ranking Assessment Model), EURAM (European Union Risk Ranking Method), ARET (Accelerated Reduction/Elimination of Toxics), CRSKorea, and other systems. The additional assessment factors of CRS suitable for soil pollutants were suggested. We suggest soil adsorption factor as an appropriate factor of CRS system to consider chemical transport from soil to groundwater. Other factors such as soil emission rate and cases of accident of soil pollutants were included. These results were reflected to screen the priority chemicals in Korea, as a part of the project entitled ‘Setting the Priority of Soil Contaminants'.

Thermal Insulation Effect of Inflatable Life Vest on the Drowned Individual estimated by Numerical Analysis (익수자 체온 저하에 미치는 팽창식 구명동의의 단열효과 수치 분석)

  • Kim, Sung Chan;Lee, Kyung Hoon;Hwang, Se Yun;Lee, Jin Sung;Lee, Jang Hyun
    • Journal of Navigation and Port Research
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    • v.39 no.4
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    • pp.285-291
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    • 2015
  • Exposure to cold sea water can be life-threatening to the drowned individual. Although appropriate life jacket can be usually be provided for the buoyance at the drowning accident, heat loss can make the drowned individual experience the hypothermia. Inflatable life jackets filled with inflatable air pocket can increase the thermal protection as well as the buoyancy force. Because it is important to know how the human body behaves unde the different life jacket, present study compares the thermal insulation capacity of solid type life jacket with that of inflatable life jacket. In order to represent the insulation capacity of life jacket, thermal resistance is estimated based on the assumption of steady-state. Also, a transient three-dimensional thermal distribution of the thigh is analyzed by using finite element method implementing the Pennes bioheat equation. The finite element model is a segmental, multi-layered representation of the body section which considers the heat conduction within tissue, bone, fat and local blood flow rate.

Estimation of fire Experiment Prediction by Utility Tunnels Fire Experiment and Simulation (지하공동구 화재 실험 및 시뮬레이션에 의한 화재 설칠 예측 평가)

  • 윤명오;고재선;박형주;박성은
    • Fire Science and Engineering
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    • v.15 no.1
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    • pp.23-33
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    • 2001
  • The utility tunnels are the important facility as a mainstay of country because of the latest communication developments. However, the utilities tunnel is difficult to deal with in case of a fire accident. When a cable burns, the black smoke containing poisonous gas will be reduced. This black smoke goes into the tunnel, and makes it difficult to extinguish the fire. Therefore, when there was a fire in the utility tunnel, the central nerves of the country had been paralyzed, such as property damage, communication interruption, in addition to inconvenience for people. This paper is based on the fire occurred in the past, and reenacting the fire by making the real utilities tunnel model. The aim of this paper is the scientific analysis of the character image of the fire, and the verification of each fire protection system whether it works well after process of setting up a fire protection system in the utilities tunnel at a constant temperature. The fire experiment was equipped with the linear heat detector, the fire door, the connection water spray system and the ventilation system in the utilities tunnel. Fixed portion of an electric power supply cable was coated with a fire retardant coating, and a heating tube was covered with a fireproof. The result showed that the highest temperature was $932^{\circ}c$ and the linear heat detector was working at the constant temperature, and it pointed at the place of the fire on the receiving board, and Fixed portion of the electric power supply cable coated with the fire retardant coating did not work as the fireproof. The heating tube was covered with the fireproof about 30 minutes.

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