• Title/Summary/Keyword: Event Study

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A Study on the Constructions of Fire Events Probabilistic Safety Assessment Model for Nuclear Power Plants (원자력발전소의 화재사건 확률론적안전성평가 모델 구축에 관한 연구)

  • Kang, Dae Il;Kim, Kilyoo
    • Journal of the Korean Society of Safety
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    • v.31 no.5
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    • pp.187-194
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    • 2016
  • A single fire event within a fire area can cause multiple initiating events considered in internal events probabilistic safety assessment (PSA). For an example, a fire event in turbine building fire area can cause a loss of the main feed-water and loss of off-site power initiating events. This fire initiating event could result in special plant responses beyond the scope of the internal events PSA model. One approach to address a fire initiating event is to develop a specific fire event tree. However, the development of a specific fire event tree is difficult since the number of fire event trees may be several hundreds or more. Thus, internal fire events PSA model has been generally constructed by modifications of the pre-developed internal events PSA model. New accident sequence logics not covered in the internal events PSA model are separately developed to incorporate them into the fire PSA model. Recently, many fire PSA models have fire induced initiating event fault trees not shown in an internal event PSA model. Up to now, there has been no analytical comparative study on the constructions of fire events PSA model using internal events PSA model with and without fault trees of initiating events. In this study, the changing process of internal events PSA model to fire events PSA model is analytically presented and discussed.

Exploratory Study of International Sports Event Life Cycle (복합종목 국제스포츠이벤트 생애주기에 대한 탐색적 연구)

  • Kwon, Kisung;Oh, Taeyeon
    • Journal of Sport and Applied Science
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    • v.3 no.1
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    • pp.1-14
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    • 2019
  • Numerous types of sporting events have been hosted in Korea during the last decades. Sport events produce various types of data, and there is a clear necessity of storing and utilizing this information. From this background, the purpose of this study is to draw complex sports categories from international sport events life cycles in order to categorize standards of knowledges management system. This study utilized qualitative methods: expert groups discussion for overall life cycle steps and in-depth interviews for detail life cycle steps. The results show that there are several life cycle steps: bidding, preparation, operation, evaluation, post management steps. To be more specific, for the bidding step, there are check, plan, implementing detail phase; and the preparation step is based on event preparation Basis Build, event preparation implementation, test and supplementation phases. For the operation step, event operation system switch, event operation during the period, finish operation phases are deducted. Evaluation and post management step do not have detail phases. Efforts to store and utilize knowledge can be one of the starting points to make the operation of sport events efficiently.

A Study on Quantitative Modeling for EPCIS Event Data (EPCIS Event 데이터 크기의 정량적 모델링에 관한 연구)

  • Lee, Chang-Ho;Jho, Yong-Chul
    • Journal of the Korea Safety Management & Science
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    • v.11 no.4
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    • pp.221-228
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    • 2009
  • Electronic Product Code Information Services(EPCIS) is an EPCglobal standard for sharing EPC related information between trading partners. EPCIS provides a new important capability to improve efficiency, security, and visibility in the global supply chain. EPCIS data are classified into two categories, master data (static data) and event data (dynamic data). Master data are static and constant for objects, for example, the name and code of product and the manufacturer, etc. Event data refer to things that happen dynamically with the passing of time, for example, the date of manufacture, the period and the route of circulation, the date of storage in warehouse, etc. There are four kinds of event data which are Object Event data, Aggregation Event data, Quantity Event data, and Transaction Event data. This thesis we propose an event-based data model for EPC Information Service repository in RFID based integrated logistics center. This data model can reduce the data volume and handle well all kinds of entity relationships. From the point of aspect of data quantity, we propose a formula model that can explain how many EPCIS events data are created per one business activity. Using this formula model, we can estimate the size of EPCIS events data of RFID based integrated logistics center for a one day under the assumed scenario.

Comparative Study of Interrelationship between Events and Architectural Space (사건과 건축공간의 관계성 비교 연구)

  • Lee, Mi-Kyung
    • Korean Institute of Interior Design Journal
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    • v.22 no.1
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    • pp.132-142
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    • 2013
  • An event as philosophical thought is expanded throughout our society and affected largely an architectural field as well as aesthetics. Paying attention to this fact, this study is to relate the event to an architectural space and to find an interrelationship between them. Since Martin Heidegger who started to be regarded the event as a subject of thought, many philosophers revealed different thoughts about it. Architecture works of Louis I. Kahn, Peter Zumthor, Steven Holl, Bernard Tschumi, Rem Koolhaas who had the influences from the thoughts of Martin Heidegger, M. Merleau-Ponty, Jacques Derrida, Gilles Deleuze, are analyzed and compared their features. The reason why this relationship has become the subject of research is because the event can be confirmed to be connected with an architectural thoughts by correlating with aesthetic texts. Throughout this study, each architect, who is affected from philosophers, has different characters as they have different thoughts about events. This study is expected to be used as an literature data of intertextuality of philosophy and architecture.

Gait-Event Detection for FES Locomotion (FES 보행을 위한 보행 이벤트 검출)

  • Heo Ji-Un;Kim Chul-Seung;Eom Gwang-Moon
    • Journal of the Korean Society for Precision Engineering
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    • v.22 no.3 s.168
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    • pp.170-178
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    • 2005
  • The purpose of this study is to develop a gait-event detection system, which is necessary for the cycle-to-cycle FES control of locomotion. Proposed gait event detection system consists of a signal measurement part and gait event detection part. The signal measurement was composed of the sensors and the LabVIEW program for the data acquisition and synchronization of the sensor signals. We also used a video camera and a motion capture system to get the reference gait events. Machine learning technique with ANN (artificial neural network) was adopted for automatic detection of gait events. 2 cycles of reference gait events were used as the teacher signals for ANN training and the remnants ($2\sim5$ cycles) were used fur the evaluation of the performance in gait-event detection. 14 combinations of sensor signals were used in the training and evaluation of ANN to examine the relationship between the number of sensors and the gait-event detection performance. The best combinations with minimum errors of event-detection time were 1) goniometer, foot-switch and 2) goniometer, foot-switch, accelerometer x(anterior-posterior) component. It is expected that the result of this study will be useful in the design of cycle-to-cycle FES controller.

Analysis of Mega Event effect using System Dynamics : Application in Millennial Anniversary of the Tripitaka Koreana (시스템다이내믹스를 이용한 메가이벤트 개최 효과 분석: 대장경문화축전에의 적용)

  • Park, Gyung-Yeol;Choi, Seung-Dam;Kim, Dong-Hwan
    • Korean System Dynamics Review
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    • v.14 no.1
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    • pp.31-53
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    • 2013
  • The purpose of this study is to explain the impact of hosting mega event using the system dynamics and to establish the model for analysis of the impact of hosting mega event. The results are as follows. First, the growth of inbound tourists have influenced long term effect. Second, the export has increased for a limited period only after the hosting mega event, but the increase in export returned to the previous state in terms of economic impact of mega event. Third, nation brand has been improved for a limited period only such as the economical impact in terms of socio-cultural impact of mega event. Last, citizenship consciousness has been improved after hosting mega event. Further researches have to be carried out to modify and reinforce the model.

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The Effects of a Marine Leisure Exhibition Event's Appraisal Attributes on Visitors' Satisfaction and Re-visit Intention

  • Cho, Woo-Jeong
    • Journal of Navigation and Port Research
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    • v.35 no.4
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    • pp.335-342
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    • 2011
  • The purposes of this study were to analyze the effects of a marine leisure exhibition event(MLEE)'s appraisal attributes on visitors' satisfaction and rep-visit intention and thus provide fundamental information that facilitates developing effective marketing and operational strategies for a MLEE. In order to accomplish such purposes, this study employed a survey with a total of 300 visitors to a MLEE hosted by G Province. Questionnaires were developed on the basis of related studies and modified to reflect the study context. Then, such questionnaires were verified to be valid and reliable through content validity, factor analysis and internal consistency analysis. Valid 286 questionnaires were analyzed with correlation analysis and multiple regression analysis on significance level of .05. Following findings were derived from current study. First of all, the appraisal attributes of a MLEE had a significant effect on visitors' satisfaction and among them only the factor of event program had a unique relation with the levels of satisfaction. In addition, the appraisal attributes of the MLEE also had a significant effect on visitors' rep-visit intention behavior and among them event program, transportation and employee factors had unique relations with the performance variable in order. In conclusion, all the research hypotheses that had been set up through previous studies were confirmed in this study.

Analysis of bivariate recurrent event data with zero inflation

  • Kim, Taeun;Kim, Yang-Jin
    • Communications for Statistical Applications and Methods
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    • v.27 no.1
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    • pp.37-46
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    • 2020
  • Recurrent event data frequently occur in clinical studies, demography, engineering reliability and so on (Cook and Lawless, The Statistical Analysis of Recurrent Events, Springer, 2007). Sometimes, two or more different but related type of recurrent events may occur simultaneously. In this study, our interest is to estimate the covariate effect on bivariate recurrent event times with zero inflations. Such zero inflation can be related with susceptibility. In the context of bivariate recurrent event data, furthermore, such susceptibilities may be different according to the type of event. We propose a joint model including both two intensity functions and two cure rate functions. Bivariate frailty effects are adopted to model the correlation between recurrent events. Parameter estimates are obtained by maximizing the likelihood derived under a piecewise constant hazard assumption. According to simulation results, the proposed method brings unbiased estimates while the model ignoring cure rate models gives underestimated covariate effects and overestimated variance estimates. We apply the proposed method to a set of bivariate recurrent infection data in a study of child patients with leukemia.

Representation of Event-Based Ontology Models: A Comparative Study

  • Ali, Ashour;Noah, Shahrul Azman Mohd;Zakaria, Lailatul Qadri
    • International Journal of Computer Science & Network Security
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    • v.22 no.7
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    • pp.147-156
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    • 2022
  • Ontologies are knowledge containers in which information about a specified domain can be shared and reused. An event happens within a specific time and place and in which some actors engage and show specific action features. The fact is that several ontology models are based on events called Event-Based Models, where the event is an individual entity or concept connected with other entities to describe the underlying ontology because the event can be composed of spatiotemporal extents. However, current event-based ontologies are inadequate to bridge the gap between spatiotemporal extents and participants to describe a specific domain event. This paper reviews, describes and compares the existing event-based ontologies. The paper compares various ways of representing the events and how they have been modelled, constructed, and integrated with the ontologies. The primary criterion for comparison is based on the events' ability to represent spatial and temporal extent and the participants in the event.

The Impact of COVID-19 on Stock Price: An Application of Event Study Method in Vietnam

  • PHUONG, Lai Cao Mai
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.5
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    • pp.523-531
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    • 2021
  • Vietnam's Oil and gas industry make a significant contribution to the Gross Domestic Product of Vietnam. The ongoing COVID-19 pandemic has hit every industry hard, but perhaps the one industry which has taken the biggest hit is the global oil and gas industry. The purpose of this article is to examine how the COVID-19 pandemic affects the share price of the Vietnam Oil and Gas industry. The event study method applied to Oil and Gas industry index data around three event days includes: (i) The date Vietnam recognized the first patient to be COVID-19 positive was January 23, 2020; (ii) The second outbreak of COVID-19 infection in the community began on March 6, 2020; (iii) The date (30/3/2020) when Vietnam announced the COVID-19 epidemic in the whole territory. This study found that the share price of the Vietnam Oil and Gas industry responded positively after the event (iii) which is manifested by the cumulative abnormal return of CAR (0; 3] = 3.8% and statistically significant at 5 %. In the study, event (ii) has the most negative and strong impact on Oil and Gas stock prices. Events (i) favor negative effects, events (iii) favor positive effects, but abnormal return change sign quickly from positive to negative after the event date and statistically significant shows the change on investors' psychology.