• 제목/요약/키워드: Determination Factor

검색결과 1,183건 처리시간 0.029초

회귀분석에 의한 TOC 농도 추정 - 오수천 유역을 대상으로 - (Application of Regression Analysis Model to TOC Concentration Estimation - Osu Stream Watershed -)

  • 박진환;문명진;한성욱;이형진;정수정;황경섭;김갑순
    • 환경영향평가
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    • 제23권3호
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    • pp.187-196
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    • 2014
  • The objective of this study is to evaluate and analyze Osu stream watershed water environment system. The data were collected from January 2009 to December 2011 including water temperature, pH, DO, EC, BOD, COD, TOC, SS, T-N, T-P and discharge. The data were used for principle component analysis and factor analysis. The results are as followes. The primary factors obtained from both the principal component analysis and the factor analysis were BOD, COD, TOC, SS and T-P. Once principal component analysis and factor analysis have been performed with the collected data and then the results will be applied to both simple regression model and multiple regression model. The regression model was developed into case 1 using concentrations of water quality parameters and case 2 using delivery loads. The value of the coefficient of determination on case 1 fell between 0.629 and 0.866; this was lower than case 2 value which fell between 0.946 and 0.998. Therefore, case 2 model would be a reliable choice.The coefficient of determination between the estimated figure using data which was developed to the regression model in 2012 and the actual measurement value was over 0.6, overall. It can be safely deduced that the correlation value between the two findings was high. The same model can be applied to get TOC concentrations in future.

영재의 학업성취에 영향을 주는 심리적 요인들: 자기결정성, 학습목표지향성, 자기효능감, 지능관 및 자기조절학습전략을 중심으로 (A Study of Factors Effecting on Gifted Students' Achievement : Self-determination, Learning Goal-orientation, Self-efficacy, Implicit Theory of Intelligence, and Self-regulated Learning Strategy)

  • 조선미
    • 영재교육연구
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    • 제21권3호
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    • pp.611-630
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    • 2011
  • 본 연구는 영재들의 학업성취에 영향을 주는 심리적 요인인 자기결정성, 학습목표지향성, 자기효능감, 지능관 및 자기조절학습전략의 영향력을 조사하는데 목적이 있다. 또한 영재들 중 학업성취가 높은 학생과 낮은 학생들의 심리적 특성에 차이가 있는지도 살펴보았다. 한국교육종단연구 자료 중 중학교 2학년 영재학생 128명의 자료가 최종 분석되었다. 분석 결과 외적 조절동기는 학업성취에 부적영향을 주는 것으로 나타났고 확인된 조절동기, 숙달접근, 자기효능감, 정교화, 초인지 전략은 정적영향을 주는 것으로 나타났다. 단계적 중다 회귀분석을 통해 학업성취에 영향을 준 6개 하위요인들의 상대적 영향력을 비교하였는데 분석결과 영재들의 학업성취는 정교화에 의해 15.5% 가량이 설명되었고 확인된 조절동기에 의해 추가로 5% 정도 더 설명되었다. 독립표본 t 검정 분석결과 학업성취가 낮은 영재학생들은 자기결정성, 숙달접근성, 자기효능감, 정교화, 초인지, 공간관리, 교사도움에서 낮은 수준을 보였다. 따라서 성적이 낮은 중학교 영재들의 학업문제를 해결하기 위해서는 우선적으로 정교화 인지전략을 발달시킬 필요가 있다.

비용 종속적인 개선지수를 고려한 최적 예방보전 정책 (Optimal Preventive Maintenance Policy with Cost-dependent Improvement Factor)

  • 홍석수;박종훈;이창훈
    • 대한산업공학회지
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    • 제36권2호
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    • pp.108-116
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    • 2010
  • The maintenance of a deteriorating system is often imperfect. Previous studies have shown that the imperfect preventive maintenance (PM) can reduce the wear out and aging effects of deteriorating systems to a certain level between the conditions of as good as new and as bad as old. In this paper, we employ the concept of the improvement factor in investigating two optimal PM policies; failure limit policy and periodic PM policy. We redefine the improvement factor model as a function of the cost of PM, using this concept, we derive the conditions of optimal PM policies and formulate expressions to compute the expected cost rate. Based on this information, the determination of the maintenance policies which minimize the cost rate is examined. Numerical examples for the Weibull distribution case are also given.

Adaptive Leaky Factor Determination for Robust Video Transmission over Error-Prone Networks

  • Kim, Jun-Hyung;Hwang, Min-Cheol;Wang, Tae-Shick;Nam, Ju-Hun;Ko, Sung-Jea
    • 한국방송∙미디어공학회:학술대회논문집
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    • 한국방송공학회 2009년도 IWAIT
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    • pp.263-266
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    • 2009
  • When video packets are transmitted over error-prone networks, the leaky prediction can be used to mitigate the effect of error propagation. The leaky factor provides trade-off between coding efficiency and error resilience in the leaky prediction. In this paper, we propose an improved leaky prediction method where the leaky factor is adaptively determined for each frame by minimizing the estimated end-to-end distortion at the encoder. Experimental results show that the proposed method with the adaptive leaky factor shows the better performance of the error robustness as compared with the conventional method.

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통행차량에 의한 충격계수 산정방법 개선 (An Improvement for Impact Factor Determination to Traffic Loads)

  • 구봉근;류택은;이재범;류연종
    • 한국구조물진단유지관리공학회 논문집
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    • 제6권2호
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    • pp.217-224
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    • 2002
  • This paper is proposed a reasonable method for determining the dynamic properties, the impact factors caused by traffic loads on highway bridges. In addition, the impact factors obtained in previous inspection reports were classified by the span length of the bridge, kind of bridge and type of bridge and the result of the impact factor was adjusted by a statistical method and presented problems. Also, the method for determining the impact factor using traffic load is proposed and the proposed method is compared with the specification code. The method estimating the impact factors due to the traffic loads can efficiently recognize the response of the structure by providing the impact factors and help to save the investigation cost, and also it can be used for the maintenance of structures using the usual test of bridges.

New stability equation for columns in unbraced frames

  • Essa, Hesham S.
    • Structural Engineering and Mechanics
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    • 제6권4호
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    • pp.411-425
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    • 1998
  • The effective length factor of a framed column may be determined by means of the alignment chart procedure. This method is based on many unrealistic assumptions, among which is that all columns have the same stiffness parameter, which is dependent on the length, axial load, and moment of inertia of the column. A new approximate method is developed for the determination of effective length factors for columns in unbraced frames. This method takes into account the effects of inelastic column behaviour, far end conditions of the restraining beams and columns, semi-rigid beam-to-column connections, and differentiated stiffness parameters of columns. This method may be implemented on a microcomputer. A numerical study was carried out to demonstrate the extent to which the involved parameters affect the K factor. The beam-to-column connection stiffness, the stiffness parameter of columns, and the far end conditions of restraining members have a significant effect on the K factor of the column under investigation. The developed method is recommended for design purposes.

전기철도 터널 및 고가 구조물의 차폐계수 산정에 대한 연구 (A Study on the Determination of the Screening Factors for the Tunnel and the Overbridge of the Electric Railway)

  • 최경;이향범;김형석;김학철
    • 전기학회논문지
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    • 제67권9호
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    • pp.1249-1256
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    • 2018
  • For the screening factor of the tunnel and overbridge structure in the electrified railway, the ITU-T regulation denotes only a theoretical estimation method, and the actual numeric values are notified differently by the official announcement of each nations. In this study, the factors which can affect the screening factor are investigated and analysed by FEM and a suitable calculation method based on multi-conductor line theory for the current pre-estimation formula for the induction noise voltage in the national notice is presented. The case studies are performed using the real data of the tunnel and the overbridge of the electrified railway, and a satisfactory formula for the determining of screening factor is derived.

시력교정수술환자의 병원선택요인과 만족도 (Hospital Selection Factors and Patient Satisfaction of Refractive Surgery Patients)

  • 이구슬;손태용
    • 보건의료산업학회지
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    • 제6권4호
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    • pp.279-294
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    • 2012
  • The study compared refractive surgery patients' hospital selection factors and satisfaction, through this to see the factors influencing patients' satisfaction, aiming at 235 patients visiting two Eye hospitals. The research results are followed. First, target group's hospital selection factors appeared facilities and environment factor, reliability factor, personal service factor, and accessibility factor in the order. Second, patients' satisfaction appeared reliability factor, facilities and environment factor, and personal factor in the order. Fourth, in the result comparing patients' expectation on hospital selection and satisfaction score, all factors of facilities and environment, personal service, and reliability had high satisfaction score than expectation. Third, in the result of factors influencing refractive surgery patients' satisfaction, in surgery determination period, surgery expenditure, and hospital selection factors among characteristics relating to refractive surgery, facilities and environment, personal service, and reliability appeared as satisfaction influencing factors. In conclusion, the study found that hospital selection factors and satisfaction influencing factors by refractive surgery patients' surgery type are considered to be able to be used to establish marketing strategy in the fields excluded from insurance application, the researches to improve patients' satisfaction in patient-oriented medical market should be continuously proceeded.

고유변동성, 조건부 유동성, 그리고 주식수익률의 횡단면에 관한 연구 (Idiosyncratic Volatility, Conditional Liquidity, and Cross-section of Stock Returns in Korea)

  • 윤상용;조성순;박순홍
    • 아태비즈니스연구
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    • 제12권1호
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    • pp.121-134
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    • 2021
  • Purpose - This study examines whether flight-to-liquidity (FTL) explains the dynamic liquidity risk on stock returns, and whether it has a significant influence on determinants the cross-section of stock returns. Design/methodology/approach - This study suggests a new risk factor, dynamic liquidity hedge portfolio (DLP), to reflect the dynamic impact of liquidity risk on stock returns and the Fama-MacBeth 2 stage regression analysis is employed in order to analyze the data. Findings - First, the DLP factor shows more positive and significant beta for the small or illiquidity stocks. Second, the DLP shows a different influence than SMB (size risk factor), HML (value risk factor), NMP (liquidity risk factor), FTVOL (total volatility factor) in determining the cross-section of stock returns. In addition, the DLP has a statistically significant risk premium of around 5%, which is relatively larger than other risk factors. Research implications or Originality - This study has academic value in terms of newly confirming that the DLP factor has a more significant impact on cross-sectional determination of stock returns than other risk factors by proposing a conditional liquidity factor that can explain the FTL phenomenon.