• Title/Summary/Keyword: occurrence probability

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Analysis on the Occurrence Probability Distribution of Tidal Levels using Harmonic Constants (조화상수를 이용한 조위 발생확률분포 분석)

  • Jeong Shin Taek;Cho Hong Yeon;Kim Jeong Dae;Cho Byum Jun
    • Proceedings of the Korea Water Resources Association Conference
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    • 2005.05b
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    • pp.1053-1057
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    • 2005
  • The occurrence probability (OP) distributions of tide levels using harmonic constants of six tidal gauging stations in Korean coastal zone were estimated and analysed in detail. OP analysis using harmonic constants data of Incheon(Youldo), Mokpo, Yeosu, Pusan, Pohang and Sokcho was carried out and compared with the OP using hourly tidal elevation data which were served through the Internet Homepage by the National Ocean Research Institute. The tidal elevation data were divided by the AHHW (ALLW) value referenced to MSL in order to compare the OP patterns in a relative scale. The OP of the tidal elevation calculated using 38 harmonic tidal constituents relatively well agreed with those of hourly observed tidal elevation data. However, the OP results using four harmonic tidal constituents overestimate the occurrence probability at the peak points and underestimate at the tail-regions of the OP. Especially, the OP patterns of the Sokcho and Pohang tidal gauging stations on the East Sea show totally different patterns and the estimation method using four harmonic constants should be modified and application should be strictly limited on the East Sea areas. The OP patterns are considerably well generated in case of the OP generation using the additional two or three dominant tidal constituents,

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Risk Assessment for Marine Pilot Occupational Accidents using Fault Tree and Event Tree Analysis

  • Camliyurt, Gokhan;Choi, Sea-Am;Kim, So-Ra;Guzel, Ahmet Turgut;Park, Young-Soo
    • Journal of Navigation and Port Research
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    • v.46 no.5
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    • pp.400-408
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    • 2022
  • Maritime transportation is one of the most complicated and hazardous business fileds. Maritime accidents still occur despite several precautions since maritime is exposed to natural factors more than any other industries. In this harsh environment as a part of their job, marine pilots often embark/disembark to/ from vessels and confront life-endangering personal accidents. In the maritime field, several risk assessments are applied. However, all of them could not evaluate occupational accident risk for maritime pilot specifically. This paper performs specific risk analysis using the bow-tie method based on past accident records. This paper aims to qualify root causes and quantify root causes by importance level according to occurrence probability. As a result of analysis, occupational accident occurrence probability is found to be 14%, indicating that accident occurrence rate is significantly high. Hence, the probability of root causes triggering accidents and accident occurrence probability can be ascertained so that preventive measurements can be implemented. Besides theoretical achievement, this paper provides safety awareness to marine pilots, Marine Pilot Organizations, and ship crew who play a key role during marine pilots' transfer.

Classification of Forest Fire Occurrence Risk Regions Using Forest Site Digital Map (수치산림입지도를 이용한 산불발생위험지역 구분)

  • An Sang-Hyun;Won Myoung-Soo;Kang Young-Ho;Lee Myung-Bo
    • Fire Science and Engineering
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    • v.19 no.3 s.59
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    • pp.64-69
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    • 2005
  • In order to decrease the area damaged by forest fires and to prevent the occurrence of forest fires, we are making an effort to improve prevention measures for forest fires. The objective of this study is developing the forest fire occurrence probability model by means of forest site characteristics such as soil type, topography, soil texture, slope, and drainage and forest fire sites. Conditional probability analysis and GIS were used in developing the forest fire occurrence probability model that was used in the classification of forest fire occurrence risk regions.

A Probability Modeling of the Crime Occurrence and Risk Probability Map Generation based on the Urban Spatial Information (도시공간정보 기반의 범죄발생 확률 모형 및 위험도 확률지도 생성)

  • Kim, Dong-Hyun;Park, Koo-Rack
    • Journal of the Korea Society of Computer and Information
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    • v.14 no.10
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    • pp.207-215
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    • 2009
  • Recently, the research of the analysis of the crime spatial is increased by using the computer information technology and GIS (Geometric Information System) in order to prevent the urban crime so as to increase the urbanization rate. In this paper, a probability map formed by the raster is organized by the quantification of crime risk per the cell using the region property of the urban spatial information in the static environment. Also, a map of the risk probability is constructed based on the relative risk by the region property, the relative risk by the facility, the relative risk by the woody plant and the river, and so on. And, this integrated risk probability map is calculated by averaging the individual cell risk applied to the climatic influence and the seasonal factor. And, a probability map of the overall risk is generated by the interpretation key of the crime occurrence relative risk index, and so, this information is applied to the probability map quantifying the occurrence crime pattern. And so, in this paper, a methodology of the modeling and the simulation that this crime risk probability map is modified according to the passage of time are proposed.

A Research on Process of Estimation about Frequency and Loss of Risk by distribution of Probability (확률분포에 의한 리스크 빈도수와 손실규모 추정 프로세스 연구)

  • Lee, Young-Jai;Lee, Seong-Il
    • Journal of Information Technology Applications and Management
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    • v.15 no.2
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    • pp.67-82
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    • 2008
  • Risk that breed large size disaster is happening variously for cause at social. natural a management. Incidence and damage scale are trend that increase rapidly than past. In these circumstance, to keep operational continuity of organization, area, society, risk management action that establish systematic counter measure estimating and analyze occurrence possibility and expectation damage of risk is essential indispensable issue and the best countermeasure. Risk management action does by main purpose establish optimum disaster reduction countermeasure. To deduce various countermeasure, process that estimate and analyze occurrence possibility and expectation damage of risk is essential indispensable issue. Therefore, this paper studies process design that can presume risk occurrence frequency and damage scale through distribution of probability.

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Quantitative Hazard Analysis of Information Systems Using Probabilistic Risk Analysis Method

  • Lee, Young-Jai;Kim, Tae-Ho
    • Journal of Information Technology Applications and Management
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    • v.16 no.3
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    • pp.59-71
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    • 2009
  • Hazard analysis identifies probability to hazard occurrence and its potential impact on business processes operated in organizations. This paper illustrates a quantitative approach of hazard analysis of information systems by measuring the degree of hazard to information systems using probabilistic risk analysis and activity based costing technique. Specifically the research model projects probability of occurrence by PRA and economic loss by ABC under each identified hazard. To verify the model, each computerized subsystem which is called a business process and hazards occurred on information systems are gathered through one private organization. The loss impact of a hazard occurrence is produced by multiplying probability by the economic loss.

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The Human Performance Degradation in Vigilance due to Prolonged and Monotonous Tasks (경계(警戒) 임무(任務) 담당자(擔當者)의 시간지연(時間遲延)에 따르는 인간(人間) 성능(性能)의 변화(變化)에 대(對)한 연구(硏究) 및 개선방안(改善方案))

  • Myun-Woo,Lee
    • Bulletin of the Society of Naval Architects of Korea
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    • v.11 no.1
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    • pp.27-34
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    • 1974
  • This study is aimed at a validation of the vigilance simulation model which was proposed earlier (2). The model estimates a perceived danger value, an alertness level and the probability of detection at a given elapsed time of vigilance. Twenty-nine male and seven female subjects were given a simple task. They were asked to detect a number(four numbers out of six digits in the telephone directory which have the probability of occurrence in the range of 0.0010-0.0018) in six different experimental conditions, for periods of two to three hours. Analysis of the experiments showed that although the mean detection rate varied slightly in two hours, the within-subject variance and the number of cyclic performance fluctuations increased significantly. A primal factor that affects the performance seems to be the frequency of target occurrence. By curve fitting, the relation between the probability of detection and the percentages of danger event occurrence was derived; $y=0.50(1-{\varepsilon}^{-50x^2})+0.39$. Assuming the equation represents the normal detection rate(100% performance), the Relative Vigilance Performance Rating was calculated. This rating method could be a useful criterion in selecting and training of the vigilance personnel. The results show that the simulation model is a good estimator of human a performance when the probability of danger occurrence is greater than 0.0015; it gives a good reference for improving the vigilance system. Suggestions are made that (1) the validity of proposed functional equations over the extended range of danger probability be studied, (2) an analysis of the cyclic fluctuations of the alertness level be accomplished, and (3) the cost functions of detection reliability be included in any future model.

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Solar Flare Occurrence Rate and Probability Depending on Sunspot Classification with Active Region Area and Its Change

  • Lee, Kang-Jin;Moon, Yong-Jae
    • The Bulletin of The Korean Astronomical Society
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    • v.37 no.1
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    • pp.88.2-88.2
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    • 2012
  • We investigate solar flare occurrence rate and daily flare probability depending on McIntosh sunspot classification, its area, and its area change. For this we use the NOAA active region and GOES solar flare data for 15 years (from January 1996 to December 2010). We consider the most flare-productive 10 sunspot classification: 'Dko', 'Dai', 'Eai', 'Fai', 'Dki', 'Dkc', 'Eki', 'Ekc', 'Fki', and 'Fkc'. Sunspot area and its change can be a proxy of magnetic flux and its emergence/cancellation, respectively. we classify each sunspot group into two sub-groups: 'Large' and 'Small'. In addition, for each group, we classify it into three sub-groups according to sunspot group area change: 'Decrease', 'Steady', and 'Increase'. As a result, in the case of compact groups, their flare occurrence rates and daily flare probabilities noticeably increase with sunspot group area. We also find that the flare occurrence rates and daily flare probabilities for the 'Increase' sub-groups are noticeably higher than those for the other sub-groups. In case of the (M+X)-class flares of 'Dkc' group, the flare occurrence rate of the 'Increase' sub-group is three times higher than that of the 'Steady' sub-group. Mean flare occurrence rates and flare probabilities for all sunspot regions increase with the following order: 'Steady', 'Decrease', and 'Increase'. Our results statistically demonstrate that magnetic flux and its emergence enhance major solar flare occurrence. We are going to forecast solar flares based on these results and NOAA scale.

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Prediction of Landslide around Stone Relics of Jinjeon-saji Area (진전사지 석조문화재 주변의 산사태예측)

  • Kim, Kyeong-Su;Lee, Choon-Oh;Song, Young-Suk;Cho, Yong-Chan
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.03a
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    • pp.1378-1385
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    • 2008
  • The probability of landslide hazards was predicted to natural terrain around the stone relics of Jinjeon-saji area, which is located in Yangyang, Kangwon Province. As the analysis results of field investigation, laboratory test and geology and geomorphology data, the effect factors of landslides occurrence were evaluated, and then the landslides prediction map was made up by use of prediction model considering the effect factors. The susceptibility of stone relics induced by landslides was investigated as the grading classification of occurrence probability using the landslides prediction map. In the landslides prediction map, the high probability area of landslides over 70% of occurrence probability was 3,489m3, which was 10.1% of total prediction area. If landslides are occurred at the high elevation area, the three stories stone pagoda of Jinjeon-saji (National treasure No.122) and the stone lantern of Jinjeon-saji (Treasure No.439) will be collapsed by debris flow.

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Predicting on Human-caused Forest Fire Occurrence in South Korea

  • Chae, Hee Mun;Lee, Chan yong
    • Journal of Korean Society of Forest Science
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    • v.95 no.2
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    • pp.160-167
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    • 2006
  • Most of the forest fires that occur in South Korea are caused by human. We partitioned South Korea into nine districts and used observed weather data and daily fire occurrence records for the 1994 to 2003 period to develop a human-caused fire occurrence model of South Korea. Logistic regression analysis techniques were used to relate the probability of a fire day to Fine Fuel Moisture Code (FFMC) component of the Canadian Forest Fire Danger Rating System. The probability of the number of fire day was increased as FFMC increased in the nine districts of South Korea.