• IEIE Transactions on Smart Processing and Computing
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• 제5권4호
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• pp.256-266
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• 2016

Concurrently detected and annotated abnormal events can have a significant impact on surveillance systems. By considering the specific domain of pedestrian trajectories, this paper presents two main contributions. First, as introduced in much of the work on trajectory-based anomaly detection in the literature, only information about pedestrian paths, such as direction and speed, is considered. Differing from previous work, this paper proposes a framework that deals with additional types of trajectory-based anomalies. These abnormal events take places when a person enters prohibited areas. Those restricted regions are constructed by an online learning algorithm that uses surrounding information, including detected pedestrians and background scenes. Second, a simple data-boosting technique is introduced to overcome a lack of training data; such a problem particularly challenges all previous work, owing to the significantly low frequency of abnormal events. This technique only requires normal trajectories and fundamental information about scenes to increase the amount of training data for both normal and abnormal trajectories. With the increased amount of training data, the conventional abnormal trajectory classifier is able to achieve better prediction accuracy without falling into the over-fitting problem caused by complex learning models. Finally, the proposed framework (which annotates tracks that enter prohibited areas) and a conventional abnormal trajectory detector (using the data-boosting technique) are integrated to form a united detector. Such a detector deals with different types of anomalous trajectories in a hierarchical order. The experimental results show that all proposed detectors can effectively detect anomalous trajectories in the test phase.

• 정보보호학회논문지
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• 제30권4호
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• pp.693-704
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• 2020

기업의 네트워크가 대규모화되고 보안시스템 수가 많아짐에 따라 엄청난 양의 보안시스템 이벤트로부터 이상 트래픽을 신속하게 탐지하기란 쉽지 않다. 본 논문에서는 방화벽 등 정보보호 시스템의 보안이벤트를 실시간 탐지하고 분석할 수 있는 트래픽 시각화 분석시스템(FDANT-PCSV)를 제안한다. FDANT-PCSV는 보안이벤트 중 5가지 인자(출발지 IP, 목적지 IP, 목적지 포트, 패킷 길이, 처리상태)를 이용한 Parallel Coordinates 시각화와 4가지 인자(출발지 IP, 목적지 IP, 이벤트 수, 데이터 크기)를 이용한 Sankey 시각화로 구성된다. 또한, 빅데이터 기반 SIEM을 이용하기 때문에 인터넷 및 인트라넷에서 발생하는 네트워크 공격과 네트워크 장애 트래픽을 실시간 탐지할 수 있다. FDANT-PCSV는 사이버 보안 관제요원과 네트워크 관리자가 네트워크 이상 트래픽을 빠르고 쉽게 탐지하여 네트워크 위협에 신속히 대응할 수 있도록 해준다.

• 한국ITS학회 논문지
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• 제22권2호
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• pp.80-92
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• 2023

도시에 많은 사람들이 밀집하여 살아가면서 기존에 예측하지 못했던 범죄, 사고, 감염병 등의 비정상 이벤트가 발생은 도시 내 이용자 수요에 영향을 미치게 된다. 이러한 불확실성(uncertainty)이 내포된 정보를 기반으로 도시 내 이용자 수요에 대한 시계열적 예측을 수행한다면 신뢰성 있는 결과 도출이 불가능하다. 특히, 2020년 초 발발한 COVID-19는 비정상적인 이동통행패턴의 변화를 불러 일으키며 시계열 수요예측을 어렵게 만들었기에 이러한 변화를 검지하고 이를 반영하여 정확한 수요를 예측 수행할 수 있는 방법론의 필요성이 대두되고 있다. 이에 본 연구는 COVID-19로 인한 비정상적 이벤트를 자동으로 검지하고 예측하는 모형 파이프라인을 구축하였다. 이는 도시 내 다양한 분야에서의 불규칙적이고 비정상적인 이벤트로 인한 수요변화가 일어나는 상황에 폭넓게 활용될 수 있을 것으로 생각된다.

• 환경영향평가
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• 제23권3호
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• pp.220-226
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• 2014

This study investigated temporal-spatial and variations in Geostationary Ocean Color Imager (GOCI) products of parameters total suspended solids (TSS) and chlorophyll-a in the North Marine Areas of East China Sea.GOCI data were collected daily from February 2012 to December 2012. The higher chlorophyll-a values were observed during the investigation period. The relatively large increase in TSS and chlorophyll-a at the sampling stations coupled with typhoon events during the summer rainy period. The abnormal chlorophyll-a concentration was mainly driven by meteorological factors such as typhoon and rainfall in the coastal areas of Jeju and the North Marine Areas of East China Sea. The abnormal high chlorophyll-a concentration at the majority of the coastal stations indicate eutrophication of coastal waters, especially Red tide. The events such as eutrophication and abnormal high chlorophyll-a concentration may potentially influence outbreak of Red Tide, detected with GOCI parameters.

• Clinical and Experimental Reproductive Medicine
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• 제44권2호
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• pp.90-95
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• 2017

Objective: We investigated whether the insemination method (in vitro fertilization [IVF] or intracytoplasmic sperm injection [ICSI]) affected morphokinetic events and abnormal cleavage events in embryonic development. Methods: A total of 1,830 normal fertilized embryos were obtained from 272 IVF and ICSI cycles that underwent ovum retrieval culture using a time-lapse system (Embryoscope) from June 2013 to March 2015. All embryos were investigated by a detailed time-lapse analysis that measured the developmental events in the hours after IVF or ICSI insemination. Results: No significant differences were observed between the two groups regarding clinical outcomes (p>0.05). ICSI-derived embryos showed significantly faster morphokinetics than those derived from conventional IVF, from the time to pronuclear fading to the time to 6 cells (p<0.05). However, no significant differences were found from the time to 7 cells to the time to expanded blastocyst (p>0.05). There were no differences in abnormal cleavage events between the two groups (p>0.05); they showed the same rates of direct cleavage from 1 to 3 cells, 2 multinucleated cells, 2 uneven cells, and reverse cleavage. Conclusion: The morphokinetics of embryo development was found to vary between IVF- and ICSI-fertilized oocytes, at least until the 6-cell stage. However, these differences did not affect the clinical outcomes of the embryo. Additionally, no significant differences in abnormal cleavage events were found according to the fertilization method.

• 한국기후변화학회지
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• 제9권4호
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• pp.461-470
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• 2018

The frequency of extreme weather events was analyzed using meteorological data (air temperature, precipitation, and duration of sunshine) collected from 61 stations over a 36-year span (1981-2016). The 10-day meteorological data were used as a basic unit for this analysis. On average, the frequency of occurrence of abnormal weather was 9.88 per year and has increased significantly during this 36-year period. According to the type of abnormal weather, the frequencies of occurrence of abnormally high air temperature and short duration of sunshine have increased by 0.50 and 0.41 per 10 years, respectively; however, that for abnormally low air temperature has decreased by 0.31 per 10 years and the trend was statistically significant. The highest frequency of abnormal weather appeared in 2007, with a frequency of 14.31. Abnormal weather was the most frequent at Yeongdeok station with an average frequency of 11.78 per year over this 36-year span.

• 한국기후변화학회지
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• 제4권4호
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• pp.317-330
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• 2013

홍수와 가뭄, 고온 등 이상기상의 영향으로 쌀 단수가 감소할 수 있다. 본 연구의 목적은 등숙기 이상기상이 쌀 단수에 미치는 영향을 파악하는 것이며, 이를 위하여 횡단면 자료와 시계열 자료를 모두 이용할 수 있는 패널모형을 이용하였다. 본 연구에서는 기상요소의 평균값을 기준으로 ${\pm}2{\sigma}$의 범위를 벗어날 때를 이상기상으로 정의하였다. 분석결과를 보면, 이상고온이 발생하였을 때 쌀 단수가 5.8~16.3% 감소, 이상고온과 폭우가 동시에 발생하였을 때 8.8~20.8% 감소하는 것으로 나타났다. 이상기상으로 인한 쌀 생산량 감소를 최소화하고, 농가의 소득안정을 위하여 고온과 폭우에 강한 신품종 개발, 농업용 수리시설의 현대화, 농작물보험 채택 등의 적응전략이 필요하다.

• The Journal of Asian Finance, Economics and Business
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• 제8권5호
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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.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 B
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• pp.552-554
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• 2003

This paper is about the method by which Power Control Unit(PCU) of Control Rod Control System(CRCS) logs events in the system and the real-time monitoring display. This method enables the functions like the event logging of Control Rod Drive Mechanism(CRDM)/power Cabinet, the off-line show of the event data logged and the on-line show by communication between the PCU and the monitoring display. Operators in a nuclear power plant must be able to grasp any possible abnormal states correctly. Because our newly designed system has a good ability to log and display the kinds, tine, and the prior and posterior states of urgent or non-urgent events, the operators can judge, maintain and repair the abnormal event more easily.

• International Journal of Advanced Culture Technology
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• 제11권3호
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• pp.83-88
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• 2023

The increasing global average temperature and the emergence of various abnormal climate phenomena are already being experienced in reality. The problems arising from climate change are expanding and becoming catastrophic, despite the efforts of various organizations to prevent them. In order to avoid climate issues from becoming black elephants, we conducted interviews with emergency planning officer from various institutions to identify potential X-events caused by climate change. The results of analyzing the anticipated X-events by these emergency planning officer revealed a chain of ripple effects associated with their occurrence. This implies that once an X-event happens, its influence is broader and more significant. Through this study, we aim to share the understanding of the ripple effects of climate X-events with many people, raising awareness of the severity of climate issues. We hope that this will serve as a starting point for more institutions, individuals, and nations to make efforts in resolving climate problems, turning X-events into opportunities rather than crises.