• 제목/요약/키워드: Auxiliary variable

검색결과 115건 처리시간 0.02초

EFFICIENT ESTIMATION OF POPULATION MEAN IN STRATIFIED SAMPLING USING REGRESSION TYPE ESTIMATOR

  • Grover Lovleen Kumar
    • Journal of the Korean Statistical Society
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    • 제35권4호
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    • pp.441-452
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    • 2006
  • Here an efficient regression type estimator for a stratified population mean is proposed under the two-phase sampling scheme. While constructing the proposed estimator, it is assumed that the first auxiliary variable x is directly and highly correlated with the study variable y, and the second auxiliary variable z is directly and highly correlated with the first auxiliary variable x. However the variable z is not directly correlated with the variable y, but they are just correlated with each other only due to their direct and high correlation with the variable x. The proposed regression type estimator is found to be always more efficient than the existing estimators defined under the same situation.

8200대 전기기관차 보조전원장치의 특성에 관한 연구 (A Study for Characteristics of the Auxiliary Inverter in the 8200 Electric Locomotive)

  • 김진용;이상준;최종묵;강승욱
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2005년도 춘계학술대회 논문집
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    • pp.237-244
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    • 2005
  • The Auxiliary Inverter supply the power to Loads of Electric Locomotive. The Auxiliary Inverter have three characteristics. First, The Auxiliary Inverter is VVVF(variable voltage variable frequency) inverter. And, the output voltage is AC $0^{\sim}440V$. Second, The Auxiliary Inverter is controled all operations by CCU(Center Control Unit). Last, The Auxiliary Inverter have the SIBMON program. This program easily displays most of all status of auxiliary inverter.

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ON RECURSIONS FOR MOMENTS OF A COMPOUND RANDOM VARIABLE: AN APPROACH USING AN AUXILIARY COUNTING RANDOM VARIABLE

  • Yoora Kim
    • East Asian mathematical journal
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    • 제39권3호
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    • pp.331-347
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    • 2023
  • We present an identity on moments of a compound random variable by using an auxiliary counting random variable. Based on this identity, we develop a new recurrence formula for obtaining the raw and central moments of any order for a given compound random variable.

단위 무응답 보정에서 보조변수의 선택에 관한 연구 (A Study on Auxiliary Variable Selection in Unit Nonresponse Calibration)

  • 손창균;홍기학;이기성
    • 응용통계연구
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    • 제16권1호
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    • pp.33-44
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    • 2003
  • 조사과정에서 필연적으로 발생하는 무응답을 보정하기 위해 보조정보를 사용해야 한다. 이 때, 이용 가능한 보조정보의 차원이 크면, 계산과정에서 많은 시간이 소요되며 데이터를 다루기가 매우 어렵다. 또한 추정량의 분산이 보조전보의 차원에 의존하기 때문에 과소추정의 문제가 발생한다. 이러한 문제를 해결하기 위해 무응답 보정에서 적절한 보조정보의 선택 방법을 제안하였고, 이에 대한 효율성을 모의실험을 통해 살펴보았다.

Estimation of Median in the Presence of Three Known Quartiles of an Auxiliary Variable

  • Singh, Housila P.;Shanmugam, Ramalingam;Singh, Sarjinder;Kim, Jong-Min
    • Communications for Statistical Applications and Methods
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    • 제21권5호
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    • pp.363-386
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    • 2014
  • This paper has improved several ratio type estimators of the population median including their generalization in the presence of three known quartiles of an auxiliary variable. The properties of the improved estimators are discussed and applied. Both the empirical and simulation studies confirm that our new estimators perform efficiently.

Improved Exponential Estimator for Estimating the Population Mean in the Presence of Non-Response

  • Kumar, Sunil
    • Communications for Statistical Applications and Methods
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    • 제20권5호
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    • pp.357-366
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    • 2013
  • This paper defines an improvement for estimating the population mean of a study variable using auxiliary information and known values of certain population parameter(s), when there is a non-response in a study as well as on auxiliary variables. Under a simple random sampling without a replacement (SRSWOR) scheme, the mean square error (MSE) of all proposed estimators are obtained and compared with each other. Numerical illustration is also given.

THE CALIBRATION ESTIMATION USING TWO-STEP NEWTON'S ALGORITHM IN TWO-PHASE SAMPLING

  • Son, Chang-Kyoon;Yum, Joon-Keun
    • Journal of applied mathematics & informatics
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    • 제7권1호
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    • pp.237-245
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    • 2000
  • In this paper, we consider to the adjustment weighting procedure in the two phase sampling scheme. In general, the unit nonresponses may be occured in the final survey operation. When the unit nonresponse be generated in survey, it is able to use the auxiliary variable for estimating of interest variable. In this viewpoint, we use the two kinds level of auxiliary variable, $X_{1k}$ and $X_{2k}$ for the calibration procedure. We proprose the two-step Newton's method in the calibration estimation procedure for the two phase sampling.

보조 정보에 의한 이중적 로버스트 대체법 (Doubly Robust Imputation Using Auxiliary Information)

  • 박현아;전종우;나성룡
    • Communications for Statistical Applications and Methods
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    • 제18권1호
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    • pp.47-55
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    • 2011
  • 비대체와 회귀대체는 조사변수의 모형과 조사변수와 보조변수의 관계에 의존하며 모형이 성립되지 않는 경우 이들 대체법을 이용한 추정량의 불편성은 보장되지 않는다. 본 연구에서는 모형이 성립되지 않는 경우에도 추정량의 근사적 불편성이 성립되는 로버스트 대체법을 개발한다. 대체법 개발시 보조변수의 모수 정보를 이용하여 추정량의 효율 증대를 가져오게 한다. 모의실험을 실시하여 본 연구에 대한 이론적 결과의 타당성을 보인다.

보조권선의 전력제어에 따른 단상유도전동기의 특성비교 (A Characteristics of SPIM with Power Conversions of Auxiliary Winding)

  • 박수강;서강성;백형래;조금배;임양수;이성길;김동휘
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2002년도 하계학술대회 논문집 B
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    • pp.1149-1151
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    • 2002
  • In this paper, an auxiliary winding driving system of single-phase induction motors is described. Starting charateristics variations are obtained by controlling the auxiliary winding voltage magnitude and phase angle, while the motor's main winding is directly connected to the local utility. A variable auxiliary winding voltage phase angle is shown to yield significant torque control, providing starting and braking torque. The analysis includes the determination of the relationship between the auxiliary winding voltage phase angle and the phase angle difference between the main and auxiliary winding current. The paper proposed for adjusting an auxiliary winding voltage magnitude and phase angle. Experimental results of motor's starting characteristics with using the DC-AMP and PWM inverter for auxiliary winding power supply are shown. The drive is tested using a dynamometer to experimentally verify the results of the theory.

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A General Class of Estimators of the Population Mean in Survey Sampling Using Auxiliary Information with Sub Sampling the Non-Respondents

  • Singh, Housila P.;Kumar, Sunil
    • 응용통계연구
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    • 제22권2호
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    • pp.387-402
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    • 2009
  • In this paper we have considered the problem of estimating the population mean $\bar{Y}$ of the study variable y using auxiliary information in presence of non-response. Classes of estimators for $\bar{Y}$ in the presence of non-response on the study variable y only and complete response on the auxiliary variable x is available, have been proposed in different situations viz., (i) population mean $\bar{X}$ is known, (ii) when population mean $\bar{X}$ and variance $S^2_x$ are known; (iii) when population mean $\bar{X}$ is not known: and (iv) when both population mean $\bar{X}$ and variance $S^2_x$ are not known: single and two-phase (or double) sampling. It has been shown that various estimators including usual unbiased estimator and the estimators reported by Rao (1986), Khare and Srivastava (1993, 1995) and Tabasum and Khan (2006) are members of the proposed classes of estimators. The optimum values of the first phase sample size n', second phase sample size n and the sub sampling fraction 1/k have been obtained for the fixed cost and the fixed precision. To illustrate foregoing, we have carried out an empirical investigation to reflect the relative performance of all the potentially competing estimators including the one due to Hansen and Hurwitz (1946) estimator, Rao (1986) estimator, Khare and Srivastava (1993, 1995) and Tabasum and Khan (2006) estimator.