• Title/Summary/Keyword: Top Event

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The Development of Point Heavy Rainfall Model Based on the Cloud Physics (구름 물리학을 토대로한 지점 호우모형 개발)

  • 이재형;선우중
    • Water for future
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    • v.25 no.4
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    • pp.51-59
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    • 1992
  • Recently the pysically based precipitation model was developed by Geogakakos and Bras(1984) for the storm event. This is a modified version of the model. In a different way from the model, in this paper, it is emphasized that the hyderometeor size distribution(HSD)is subject to rainfall intensity and effects on the productivity of precipitation. The to HSD functions are applied to the equation of the outflow after mass through the cloud top and base, products of rainfall rate at the ground level, storage of cloud layer. As an input we put the meterological data observed at Chonju in Korea in our models and adjust the parameters included in it. The result show that in the model there is significant deviation between the hourly calculated rainfall rate and the observed data, while it is very small in the our model based on the two HSD.

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BACKUP AND ULTIMATE HEAT SINKS IN CANDU REACTORS FOR PROLONGED SBO ACCIDENTS

  • Nitheanandan, T.;Brown, M.J.
    • Nuclear Engineering and Technology
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    • v.45 no.5
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    • pp.589-596
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    • 2013
  • In a pressurized heavy water reactor, following loss of the primary coolant, severe core damage would begin with the depletion of the liquid moderator, exposing the top row of internally-voided fuel channels to steam cooling conditions on the inside and outside. The uncovered fuel channels would heat up, deform and disassemble into core debris. Large inventories of water passively reduce the rate of progression of the accident, prolonging the time for complete loss of engineered heat sinks. The efficacy of available backup and ultimate heat sinks, available in a CANDU 6 reactor, in mitigating the consequences of a prolonged station blackout scenario was analysed using the MAAP4-CANDU code. The analysis indicated that the steam generator secondary side water inventory is the most effective heat sink during the accident. Additional heat sinks such as the primary coolant, moderator, calandria vault water and end shield water are also able to remove decay heat; however, a gradually increasing mismatch between heat generation and heat removal occurs over the course of the postulated event. This mismatch is equivalent to an additional water inventory estimated to be 350,000 kg at the time of calandria vessel failure. In the Enhanced CANDU 6 reactor ~2,040,000 kg of water in the reserve water tank is available for prolonged emergencies requiring heat sinks.

The Evaluation of Explosion For Toluene Storage Tank by Computer-Aided Fault Tree Analysis (Fault Tree Analysis(FTA)에 의한 Toluene저장 Tank의 폭발해석)

  • Chung, Jae-Hee;Yi, Young-Seop
    • Journal of the Korean Society of Safety
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    • v.3 no.2
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    • pp.5-16
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    • 1988
  • This study is conducted to evaluate the explosion of tolune storage tank in the petrochemical plant by Fault Tree Analysis. The conclusions are as follows; 1) Fault Tree diagram and the required computer program for evaluation of explosion accident is developed. 2) The probability of the top event, explosion accident, is $1.5\;{\times}\;10^{-8}$ per year, so there is almost no possibility of explosion during the life cycle of tank. However, the probability of Gate 6 and Gate 7 is 8.8 per month, therefore, attention should be paid to them for accident prevention. 3) The number of minimal cut sets is 67 sets which are not calculated the probability of each set, because of the lack of computer capacity. All the minimal cut sets should be examined case by case. However, it is necessary to be paid attention to COM1, 126, 131, and COM4 in minimal cut sets, because the number of appearance is so high. 4) The number path sets is 70 sets which are not calculated the probability of each set, because of the lack of computer capacity. It is very useful to prepare safety checklist by using this minimal path sets. Also, the events which appear many times, 123, COM5, 139, 127 and 128, are very high in reliability.

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Vital Area Identification Analysis of A Hypothetical Nuclear Facility Using VIPEX (VIPEX를 이용한 가상 원자력시설의 핵심구역 파악 분석)

  • Lee, Yoon-Hwan;Jung, Woo-Sik;Lee, Jin-Hong
    • Journal of the Korean Society of Safety
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    • v.26 no.4
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    • pp.87-95
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    • 2011
  • The urgent VAI(Vital Area Identification) method development is required since 'The Act of Physical Protection and Radiological Emergency' that is established in 2003 requires an evaluation of physical threats in nuclear facilities and an establishment of physical protection in Korea. The KAERI(Korea Atomic Energy Research Institute) has developed the VAI methodology and VAI software called as VIPEX(Vital area Identification Package EXpert) for identifying the vital areas. This study is to demonstrate the applicability of KAERI's VAI methodology to a hypothetical facility, and to identify the importance of information of cable and piping runs when identifying the vital areas. It is necessarily needed to consider cable and piping runs to determine the accurate and realistic TEPS(Top Event Prevention Set). If the information of cable and piping runs of a nuclear power plant is not considered when determining the TEPSs, it is absolutely impossible to acquire the complete TEPSs, and the results could be distorted by missing it. The VIPEX and FTREX(Fault Tree Reliability Evaluation eXpert) properly calculate MCSs and TEPSs using the fault tree model, and provide the most cost-effective method to save the VAI and physical protection costs.

Kinematical Analysis of Projection Factors to Record Difference dur ing Women's Javelin Throwing (여자 창던지기 시 기록 차이에 따른 투사요인의 운동학적 분석)

  • Park, Jae-Myoung;Yoon, Seok-Hoon
    • Korean Journal of Applied Biomechanics
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    • v.20 no.4
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    • pp.457-467
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    • 2010
  • This study intends to analyze the projection factors' difference on each record of women's javelin throwing. For this purpose, the research analyzed the best record and the lowest one of athletes in top 1~7 ranks respectively, who participated in 2009 Daegu Pre-Championship Meeting. For analyze kinematic factors, we analyzed their game photos mainly shot by 3 cameras installed in side places. The used analysis program was Kwon3D 3.1. Analysis variables were the projection velocity, angle, height, trunk lean angle, and supporting leg's knee angle. The results concluded as follows: Different record showed statistically significant differences(p<.05) in terms of horizontal velocity and resultant velocity. There were no statistically significant differences in the variables of projection angle, its height, trunk lean angle and knee angle of support leg. But for the analyzed results to each individual characteristics, the horizontal velocity, projection height, knee angle of support leg and trunk lean angle of release event appeared to have influence on record.

Significance of the R16 Korea Contest as Culture Contents ('R16 코리아' 대회의 문화콘텐츠적 가치)

  • Kim, Gigook;Lee, Woojae
    • Cross-Cultural Studies
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    • v.39
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    • pp.97-125
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    • 2015
  • Significance of the R16 Korea Contest as Culture Contents. Known for relentless practice and intense moves, widespread presence on the Internet, strong ethnic elements highlighting Korean physical attributes and collective culture, b-boying occupies a special place in Korea today. News of four consecutive wins in major b-boy contests around the world have changed the common public conception that b-boys are simply a group of problem boys and students in hip-hop clothes intent on showing off their dance moves. B-boying is no longer perceived as a dance that is performed in the shadowy underground but as a dynamic and beautiful art form of physical expression that is part of today's popular culture. This paper examines the significance of R-16 Korea as culture contents and its main event, the World B-boy Masters Championship. It introduces how the contest has developed since 2007 to reach popular influence and gain international recognition. The paper also compares R-16 Korea to the world's four major b-boy contests, Battle Of The Year, UK B-boy Championship, Free Style Session, and Red Bull BC One to see if any distinctions could be found among them and to evaluate the significance of R-16 Korea as cultural content in its rise to one of the world's top 5 major b-boy contests. Finally, this study makes suggestions for b-boying to become more established as part of Korea's culture contents.

Big Data Analysis of the Women Who Score Goal Sports Entertainment Program: Focusing on Text Mining and Semantic Network Analysis.

  • Hyun-Myung, Kim;Kyung-Won, Byun
    • International Journal of Internet, Broadcasting and Communication
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    • v.15 no.1
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    • pp.222-230
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    • 2023
  • The purpose of this study is to provide basic data on sports entertainment programs by collecting data on unstructured data generated by Naver and Google for SBS entertainment program 'Women Who Score Goal', which began regular broadcast in June 2021, and analyzing public perceptions through data mining, semantic matrix, and CONCOR analysis. Data collection was conducted using Textom, and 27,911 cases of data accumulated for 16 months from June 16, 2021 to October 15, 2022. For the collected data, 80 key keywords related to 'Kick a Goal' were derived through simple frequency and TF-IDF analysis through data mining. Semantic network analysis was conducted to analyze the relationship between the top 80 keywords analyzed through this process. The centrality was derived through the UCINET 6.0 program using NetDraw of UCINET 6.0, understanding the characteristics of the network, and visualizing the connection relationship between keywords to express it clearly. CONCOR analysis was conducted to derive a cluster of words with similar characteristics based on the semantic network. As a result of the analysis, it was analyzed as a 'program' cluster related to the broadcast content of 'Kick a Goal' and a 'Soccer' cluster, a sports event of 'Kick a Goal'. In addition to the scenes about the game of the cast, it was analyzed as an 'Everyday Life' cluster about training and daily life, and a cluster about 'Broadcast Manipulation' that disappointed viewers with manipulation of the game content.

Estimation of Accident Probability for Dynamic Risk Assessment (동적 위험 분석을 위한 사고확률 추정 방법에 관한 연구)

  • Byeong-Cheol Park;Chae-Og Lim;In-Hyuk Nam;Sung-Chul Shin
    • Journal of the Korean Society of Industry Convergence
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    • v.26 no.2_2
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    • pp.315-325
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    • 2023
  • Recently, various dynamic risk analysis methods have been suggested for estimating the risk index by predicting the possibility of accidents and damage. It is necessary to maintain and support the safety system for responding to accidents by continuously updating the probability of accidents and the results of accidents, which are quantitative standards of ship risk. In this study, when a LNG leakage that may occur in the LN G Fuel Gas Supply System (FGSS) room during LN G bunkering operation, a reliability physical model was prepared by the change in monitoring data as physical parameters to estimate the accident probability. The scenario in which LNG leakage occur were configured with FT (Fault Tree), and the coefficient of the covariate model and Weibull distribution was estimated based on the monitoring data. The possibility of an LNG leakage, which is the top event of FT, was confirmed by changes in time and monitoring data. A method for estimating the LNG leakage based on the reliability physical analysis is proposed, which supports fast decision-making by identifying the potential LNG leakage at the accident.

Experimental Analysis of Bankruptcy Prediction with SHAP framework on Polish Companies

  • Tuguldur Enkhtuya;Dae-Ki Kang
    • International journal of advanced smart convergence
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    • v.12 no.1
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    • pp.53-58
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    • 2023
  • With the fast development of artificial intelligence day by day, users are demanding explanations about the results of algorithms and want to know what parameters influence the results. In this paper, we propose a model for bankruptcy prediction with interpretability using the SHAP framework. SHAP (SHAPley Additive exPlanations) is framework that gives a visualized result that can be used for explanation and interpretation of machine learning models. As a result, we can describe which features are important for the result of our deep learning model. SHAP framework Force plot result gives us top features which are mainly reflecting overall model score. Even though Fully Connected Neural Networks are a "black box" model, Shapley values help us to alleviate the "black box" problem. FCNNs perform well with complex dataset with more than 60 financial ratios. Combined with SHAP framework, we create an effective model with understandable interpretation. Bankruptcy is a rare event, then we avoid imbalanced dataset problem with the help of SMOTE. SMOTE is one of the oversampling technique that resulting synthetic samples are generated for the minority class. It uses K-nearest neighbors algorithm for line connecting method in order to producing examples. We expect our model results assist financial analysts who are interested in forecasting bankruptcy prediction of companies in detail.

A Study on the Relationships between Super Bowl Ad Meter and Advertising Appeals in Cultural Dimensions (슈퍼볼 애드미터와 광고 어필사이의 문화측면에서 연관성 연구)

  • Kim, Chinsol;Lee, Yuncheol
    • International Area Studies Review
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    • v.20 no.1
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    • pp.183-208
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    • 2016
  • The objective of the study was to find out whether the Super Bowl adverts with high Ad Meter scores had more advertising appeals related to U.S. culture in Hofstede's dimensions. The significance of the study lies in the analysis on U.S. consumer preferences on adverts in terms of culture under one of the most representative American sport event: Super Bowl. The study was based on a content analysis of top and bottom 10 Super Bowl adverts during a period of consecutive seven years 2005 through 2011. The top and bottom ten were grouped based on the Ad Meter scores by the USA Today. The number of adverts interpreted by two coders along with the author was 139. The coding results implies that adverts in the top 10 group carried more appeals connected to US culture in Hofstede dimensions, such as youth, untamed, and magic in uncertainty avoidance dimension. Meanwhile, such appeals as ornamental, vain, and status in high power distance dimension were mainly found in the bottom 10 adverts group. Grounded on the findings from the content analysis, links between the score levels and the presence of certain appeals may offer marketers a hint on what appeals they emphasize when producing adverts in a certain cultural bound, let alone Super Bowl adverts targeting TV viewers in the U. S. A.