• 제목/요약/키워드: Abnormal events

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Evaluation criteria for freezing and thawing of tunnel concrete lining according to theoretical and experimental analysis

  • Moon, Joon-Shik;An, Jai-Wook;Kim, Hong-Kyoon;Lee, Jong-Gun;Lattner, Tim
    • Geomechanics and Engineering
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    • 제29권3호
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    • pp.349-357
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    • 2022
  • Abnormal climate events are occurring frequently around the world. In particular, cold waves and heavy snow lead to damage and deterioration of facilities, which can cause loss of life or property damage, such as shortening the lifespan of facilities. Therefore, it is very important to prepare an appropriate maintenance system and to establish a strategy to cope with abnormal weather conditions. In this study, laboratory freezing experiments were performed to analyze the freeze-thaw characteristics affecting the tunnel concrete lining, and heat flow analysis was carried out based on the test results. Based on these experimental and theoretical analysis results, quantitative freeze-thaw evaluation criteria for tunnel concrete linings were proposed.

Outlier detection of GPS monitoring data using relational analysis and negative selection algorithm

  • Yi, Ting-Hua;Ye, X.W.;Li, Hong-Nan;Guo, Qing
    • Smart Structures and Systems
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    • 제20권2호
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    • pp.219-229
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    • 2017
  • Outlier detection is an imperative task to identify the occurrence of abnormal events before the structures are suffered from sudden failure during their service lives. This paper proposes a two-phase method for the outlier detection of Global Positioning System (GPS) monitoring data. Prompt judgment of the occurrence of abnormal data is firstly carried out by use of the relational analysis as the relationship among the data obtained from the adjacent locations following a certain rule. Then, a negative selection algorithm (NSA) is adopted for further accurate localization of the abnormal data. To reduce the computation cost in the NSA, an improved scheme by integrating the adjustable radius into the training stage is designed and implemented. Numerical simulations and experimental verifications demonstrate that the proposed method is encouraging compared with the original method in the aspects of efficiency and reliability. This method is only based on the monitoring data without the requirement of the engineer expertise on the structural operational characteristics, which can be easily embedded in a software system for the continuous and reliable monitoring of civil infrastructure.

일 지역주민의 죽음관과 돌봄행위 (The Notion of Death and Caring Behaviors in one Community)

  • 고성희;이영희
    • 대한간호학회지
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    • 제29권3호
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    • pp.688-699
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    • 1999
  • This study was to find out the perceptions of toward death and caring behavior of lay persons in one community : One Island in Puan County, Chonbuk. The methodology of this study was ethnography. For this study, the fieldwork was conducted from October 1997 to July 1998. Data collected by in-depth interview and participant observations. The participants consisted fo were 17 persons of both sexes. The key informants were four specific people. The result of this study is as follows ; The people perceived two different kinds of death. Normal death, which means death from old age. The person was respected as an ancestor God and was believed to exist forever with their offspring. Abnormal death was regarded as negative, many had fears toward this kind of death. The causes of abnormal death were supernatural phenomena and had absolute holy meanings. Whether death was good or bad, the death was not personal, but collective events as family or community affairs and was interpreted as death and birth for their offsprings. Funeral rites were family-centered and/or com munity-centered. They did normal procedures for normal deaths for abnormal deaths, there were many protective ceremonies(BuJungMagi : the prevention of the taboo of uncleanliness) for the remaining people. These ceremonies combined confucism and shamanism. Caring behavior for dying persons was ruled as community-centered, reciprocal and reality-centered principles.

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Does a Firm's IPO Affect Other Firms in the Same Conglomerate?

  • Bhadra, Madhusmita;Kim, Doyeon
    • 아태비즈니스연구
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    • 제12권3호
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    • pp.37-50
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    • 2021
  • Purpose - This study aimed to examine the behavior surrounding the Initial Public Offering (IPO) event of firms within the same conglomerate and the impact of under-pricing and Return on Equity(ROE) on a firm's abnormal stock returns. Design/methodology - This study collected data from 166 South Korean Chaebols, consisting of 355 firms distributed as 202 listed on Korea Composite Stock Price Index (KOSPI) and 153 firms listed on Korean Securities Dealers Automated Quotations (KOSDAQ) from 2000 to 2020. The Capital Asset Pricing Model (CAPM) and the multiple regression analysis were hired to analyze the data. Findings - First, we found an adverse price reaction of IPO listing in the same chaebol group, and firms with higher under-pricing affect other firms' stock prices more adversely within the conglomerate. Next, we explored a negatively significant relation between ROE and the chaebol firms' stock returns during IPO events. Research implications - The novelty of this study is there are not many empirical studies on the impact of IPO within a conglomerate. So, the findings of this study contribute to the literature for analyzing stock's abnormal returns within a conglomerate.

Consistency check algorithm for validation and re-diagnosis to improve the accuracy of abnormality diagnosis in nuclear power plants

  • Kim, Geunhee;Kim, Jae Min;Shin, Ji Hyeon;Lee, Seung Jun
    • Nuclear Engineering and Technology
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    • 제54권10호
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    • pp.3620-3630
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    • 2022
  • The diagnosis of abnormalities in a nuclear power plant is essential to maintain power plant safety. When an abnormal event occurs, the operator diagnoses the event and selects the appropriate abnormal operating procedures and sub-procedures to implement the necessary measures. To support this, abnormality diagnosis systems using data-driven methods such as artificial neural networks and convolutional neural networks have been developed. However, data-driven models cannot always guarantee an accurate diagnosis because they cannot simulate all possible abnormal events. Therefore, abnormality diagnosis systems should be able to detect their own potential misdiagnosis. This paper proposes a rulebased diagnostic validation algorithm using a previously developed two-stage diagnosis model in abnormal situations. We analyzed the diagnostic results of the sub-procedure stage when the first diagnostic results were inaccurate and derived a rule to filter the inconsistent sub-procedure diagnostic results, which may be inaccurate diagnoses. In a case study, two abnormality diagnosis models were built using gated recurrent units and long short-term memory cells, and consistency checks on the diagnostic results from both models were performed to detect any inconsistencies. Based on this, a re-diagnosis was performed to select the label of the second-best value in the first diagnosis, after which the diagnosis accuracy increased. That is, the model proposed in this study made it possible to detect diagnostic failures by the developed consistency check of the sub-procedure diagnostic results. The consistency check process has the advantage that the operator can review the results and increase the diagnosis success rate by performing additional re-diagnoses. The developed model is expected to have increased applicability as an operator support system in terms of selecting the appropriate AOPs and sub-procedures with re-diagnosis, thereby further increasing abnormal event diagnostic accuracy.

LPMS 신호분석 연구 (A Study on the Signal Analysis of Loose Parts Monitoring System)

  • 이상국
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2014년도 추계학술대회 논문집
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    • pp.839-841
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    • 2014
  • The Nuclear Steam Supply System(NSSS) is designed to provide an integrated approach that includes areas of monitoring relevant to the integrity of the NSSS. LPMS is designed to function as an alarm system by providing sensor channel alarms for the associated subsystems. LPMS is equipped to provide analysis tools for new alarm events, historical events and for historical periodically stored channel data (e.g. waveforms) for most channels. This paper is intended to introduce the diagnosis principle and abnormal symptom of loose parts monitoring system as a monitoring tool in Nuclear Steam Supply System. And also, we are going to introduce signal analysis program in order to perform the actual diagnosis in power plants.

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Display System Design Based On The Abstraction Hierarchy

  • Sohn, Kwang-Young;Shin, Hyun-Kook
    • Nuclear Engineering and Technology
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    • 제28권3호
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    • pp.339-348
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    • 1996
  • Plant monitoring algorithm developments seem to be saturated which means that display system to show the results from the algorithm should be the well-defined and interactive tools for operator's diagnosing, controlling, restoring the abnormal plant situations. On the other hand, very little generalized display design concepts and evaluations are available. Events that are unfamiliar to operators and that has not been anticipated by designers may cause great threats to the nuclear power plant system safety operation. The abstraction hierarchy, considered most popular display design methodology but not generalized for nuclear power plant design space, has ken proposed as a representation frame work that can be adopted to design interfaces and supports operators in diagnosing overlooked events that should have been considered to operate plant safely. However most practical plant display systems do not fully stick to this design concept but partially rely on their philosophy from design experiences. Abstraction hierarchy display design concept will be do scribed and the trend of Advanced Control Room(ACR) CRT design will also be presented with the conventional display for the several type of plants. Consequently this complementary material should be of interest to designer and regulators concerned with nuclear power plant.

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Development of efficient detection methods of CDK2 (or 4) activities for mass screening

  • Jeon, Yong-Jin;Yeon, Seung-Woo;Kim, Tae-Yong
    • 대한약학회:학술대회논문집
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    • 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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    • pp.154.2-154.2
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    • 2003
  • Mammalian cell cycles are tightly regulated by cyclins, cyclin dependent kinase (CDK), Retinoblatoma (Rb) protein, and cellular CDK inhibitors (CDKI). Cyelin dependent kinases (CDK) are key enzymes regulating eukaryotic cell cycle. And also it is recognized that the abnormal increase of CDK activities is one of the common events in human cancer and CDK inhibitors have therapeutic values in cancer treatment. Until now it is known that over 10 different CKDs participate in cell cycle regulation. (omitted)

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Effect of DNA methylation on the reactivity of DNA alkylating agents

  • Yoo, Ja-Kyung;Park, Hyun-Ju
    • 대한약학회:학술대회논문집
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    • 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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    • pp.359.1-359.1
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    • 2002
  • In mammalian species, CpG dinucleotides are highly methylated with 60-90% methylation at the 5-position of cytosine. The pattern of DNA methylation in a cell dramatically affects the function of the DNA by switching genes on or off. Abnormal methylation events occur during aging and in the development of many cancers. Methylated CpG was reported recently to affect the reactivity of agents (mitomycin C and benzo [a]pyrenediolepoxide) that can fromguanine adducts in DNA. (omitted)

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Assessment of weather events impacts on forage production trend of sorghum-sudangrass hybrid

  • Moonju Kim;Kyungil Sung
    • Journal of Animal Science and Technology
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    • 제65권4호
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    • pp.792-803
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    • 2023
  • This study aimed to assess the impact of weather events on the sorghum-sudangrass hybrid (Sorghum bicolor L.) cultivar production trend in the central inland region of Korea during the monsoon season, using time series analysis. The sorghum-sudangrass production data collected between 1988 and 2013 were compiled along with the production year's weather data. The growing degree days (GDD), accumulated rainfall, and sunshine duration were used to assess their impacts on forage production (kg/ha) trend. Conversely, GDD and accumulated rainfall had positive and negative effects on the trend of forage production, respectively. Meanwhile, weather events such as heavy rainfall and typhoon were also collected based on weather warnings as weather events in the Korean monsoon season. The impact of weather events did not affect forage production, even with the increasing frequency and intensity of heavy rainfall. Therefore, the trend of forage production for the sorghum-sudangrass hybrid was forecasted to slightly increase until 2045. The predicted forage production in 2045 will be 14,926 ± 6,657 kg/ha. It is likely that the damage by heavy rainfall and typhoons can be reduced through more frequent harvest against short-term single damage and a deeper extension of the root system against soil erosion and lodging. Therefore, in an environment that is rapidly changing due to climate change and extreme/abnormal weather, the cultivation of the sorghum-sudangrass hybrid would be advantageous in securing stable and robust forage production. Through this study, we propose the cultivation of sorghum-sudangrass hybrid as one of the alternative summer forage options to achieve stable forage production during the dynamically changing monsoon, in spite of rather lower nutrient value than that of maize (Zea mays L.).