• Title/Summary/Keyword: Influential observations

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Outlier Detection and Treatment for the Conversion of Chemical Oxygen Demand to Total Organic Carbon (화학적산소요구량의 총유기탄소 변환을 위한 이상자료의 탐지와 처리)

  • Cho, Beom Jun;Cho, Hong Yeon;Kim, Sung
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.26 no.4
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    • pp.207-216
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    • 2014
  • Total organic carbon (TOC) is an important indicator used as an direct biological index in the research field of the marine carbon cycle. It is possible to produce the sufficient TOC estimation data by using the Chemical Oxygen Demand(COD) data because the available TOC data is relatively poor than the COD data. The outlier detection and treatment (removal) should be carried out reasonably and objectively because the equation for a COD-TOC conversion is directly affected the TOC estimation. In this study, it aims to suggest the optimal regression model using the available salinity, COD, and TOC data observed in the Korean coastal zone. The optimal regression model is selected by the comparison and analysis on the changes of data numbers before and after removal, variation coefficients and root mean square (RMS) error of the diverse detection methods of the outlier and influential observations. According to research result, it is shown that a diagnostic case combining SIQR (Semi - Inter-Quartile Range) boxplot and Cook's distance method is most suitable for the outlier detection. The optimal regression function is estimated as the TOC(mg/L) = $0.44{\cdot}COD(mg/L)+1.53$, then determination coefficient is showed a value of 0.47 and RMS error is 0.85 mg/L. The RMS error and the variation coefficients of the leverage values are greatly reduced to the 31% and 80% of the value before the outlier removal condition. The method suggested in this study can provide more appropriate regression curve because the excessive impacts of the outlier frequently included in the COD and TOC monitoring data is removed.

The Occupational Socialization of the Security Guards in the Casinos - Case of Security Science Majors - (카지노 시큐리티 종사자의 직업사회화 과정 - 경호학 전공자들을 대상으로 -)

  • Chun, Yong-Tae
    • The Journal of the Korea Contents Association
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    • v.10 no.3
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    • pp.337-346
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    • 2010
  • The purpose of this study is to explore how security science graduates in casinos are socialized into the workplace. Participants for this study were seven security guards who work for two of three casinos for foreign customers in the city of Seoul. All the participants majored in the security science in colleges. They had 1 to 5 years of work experience. Their main job responsibilities were deterrent to crimes and watch for impending danger in the casinos. A variety of qualitative data collection techniques for this study included formal and informal interviews, stimulated-recall interview, observations, and field notes. Analytic induction and constant comparison were utilized to analyze data. Triangulating and member checks were employed to enhance trustworthiness. The findings of this study were as follow: Firstly, In acculturation, sports experience and media attraction were revealed as factors. Secondly, In professional socialization, college education and senior students in the program were found. Lastly, organizational socialization, Difficulty of relationship, lack of risk management training, lack of team cohesion, pride himself as a security guard, and unclear evaluation system. In conclusion, a variety of influential factors appeared through his occupational socialization even though there were negative and positive factors.

Related Party Transactions and Corporate Value: The Effect of Regulations against Controlling Shareholders' Expropriation in Korea (특수관계인간 거래와 기업가치: 사익편취규제제도 시행의 영향 분석)

  • Lee, Sang-Gyu;Kim, Dong-Wook;Kim, Byoung-Gon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.9
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    • pp.584-595
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    • 2020
  • This study relates to the effect from enforcement of regulations in 2014 against controlling shareholder expropriation in Korean corporations. The relationship change between related party transactions (RPTs) and the corporate values of listed Korean corporations is analyzed for the five-year period before and after enforcement of the regulations (2009-2013 and 2014-2018). Three types of RPTs regarding long-term supply contracts, loans, and credit were adopted for analysis. Following are the results of a regression analysis with panel data that consist of 6,534 firm-year observations. First shown is that the enforcement of regulations affects the relationship between RPTs and corporate value. Specifically, for all corporations, the result implies that the purpose of expropriation is weakened, and the efficiency and transparency of transactions in corporations are enhanced due to enforcement of the regulations. Secondly, the extent to which the regulations exert influence on designated and non-designated corporations differs. Regulation enforcement seems to be more influential on non-designated corporations than on designated ones for the efficiency and transparency of transactions in the long-term contract type of RPT.