• Title/Summary/Keyword: W-statistic

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Consistency of a Modified W Test for Exponentiality

  • Kim, Namhyun
    • Communications for Statistical Applications and Methods
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    • v.9 no.3
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    • pp.629-637
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    • 2002
  • Shapiro and Wilk(1972) developed a test for exponentiality with origin and scale unknown. The procedure consists of comparing the generalized least squares estimate of scale with the estimate of scale given by the sample variance. However the test based on the statistic is inconsistent Kim(2001a) proposed a modified Shapiro-Wilk's test statistic using the ratio of two asymptotically efficient estimators of scale. In this paper, we study the consistency of the proposed test.

On Testing Exponentiality Against NBURFR Class Of Life Distributions

  • Mahmoud, M.A.W.;Abdul Alim, N.A.
    • International Journal of Reliability and Applications
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    • v.4 no.2
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    • pp.57-69
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    • 2003
  • A non-parametric test based on U-statistic for testing exponentiality against the new better than used renewal failure rate (NBURFR) alternatives is introduced and the percentiles of this test statistic are tabulated for sample size 5(1)50. Its properties are also discussed including the Pitman asymptotic efficiency relative to the tests of the new better than used and new better than used failure rate (Ahmed (1994) and Hendi (2000)). The powers of this test are also calculated for some used life distributions. An example from blood cancer patients demonstrates a practical application of our test in the medical sciences is presented. Finally the problem when right-censored data is available is handled.

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Normal Probability Plots for Normality

  • Lee, Jea-Young;Rhee, Seong-Won
    • Communications for Statistical Applications and Methods
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    • v.6 no.3
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    • pp.687-694
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    • 1999
  • The goodness of fit statistics of normality plots are obtained using the Receiver Operating Characteristic(ROC) method. This work is intended to compare with Shapiro-Wilk W statistic. Wel will use and discuss an accuracy of the test and the best cut-off value which minimizes the sum of the type I and II error probabilities.

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Multivariate control charts for monitoring correlation coefficients in dispersion matrix

  • Chang, Duk-Joon;Heo, Sun-Yeong
    • Journal of the Korean Data and Information Science Society
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    • v.23 no.5
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    • pp.1037-1044
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    • 2012
  • Multivariate control charts for effectively monitoring every component in the dispersion matrix of multivariate normal process are considered. Through the numerical results, we noticed that the multivariate control charts based on sample statistic $V_i$ by Hotelling or $W_i$ by Alt do not work effectively when the correlation coefficient components in dispersion matrix are increased. We propose a combined procedure monitoring every component of dispersion matrix, which operates simultaneously both control charts, a chart controlling variance components and a chart controlling correlation coefficients. Our numerical results show that the proposed combined procedure is efficient for detecting changes in both variances and correlation coefficients of dispersion matrix.

The Importance of Fog prediction at the Incheon Int'l Airport through flight delay and cancel statistics (인천국제공항에서의 운항을 통해서 살펴본 안개예측의 중요성)

  • Leem, H.H.;Kim, D.H.;Song, K.W.
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.13 no.4
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    • pp.1-10
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    • 2005
  • According to the aviational definition, the fog is an obscuration phenomenon when prevailing visibility becomes less than 1,000m. Fog defined above causes so many aviation traffic problems like detour, flight delay and cancel. Therefore this study investigated quantitatively the fog effects on flight operation using flight delay and cancel statistic data during last four years from 1st Jul. 2001 to 30th Jun. 2005 at the Incheon Int'l Airport. The results of this study show that the hazardous meteorological condition is a important cause of flight delay and cancel, especially fog phenomenon. And it is expected that the results of this study give us the necessary and importance of fog prediction at the Incheon Int'l Airport.

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A Study on the Customer Reward Program Factors in Ski Resort (스키리조트의 고객 보상프로그램 요인에 관한 연구)

  • Byeon, Kyung-Won;Kim, Young-Ki
    • 한국체육학회지인문사회과학편
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    • v.54 no.2
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    • pp.285-297
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    • 2015
  • This study aimed to research customer reward program factors of ski resorts in Korea through surveying the expert panel side and the customer side. This study conducted survey for 28 practicians that have been working for the department of customer reception of 6 different ski resorts all over the country and 7 faculties quited well-known in the academic circles. Delphi technique has been used to conduct survey customer reward program factors of the supplier side till the 3rd survey as the final. Based on this survey, an interview and a questionnaire survey have been used to conduct survey customer reward program factors that have been aware by the 50 customers, who have visited the ski resorts in 2014, and compared those two surveys above. In order to process the data, descriptive statistic analysis and Kendall W test have been utilized PASWWIN Ver. 18.0. The results were as follows: discount factor 8 articles, promotion factor 10 articles, package factor 5 articles, and convenience factor 6 articles have been produced as a good result.

Study on Estimation of Urban Anthropogenic Heat Generation (도시의 인공열 산정에 관한 연구)

  • 손은하;김유근;홍정혜
    • Journal of Korean Society for Atmospheric Environment
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    • v.16 no.1
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    • pp.37-47
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    • 2000
  • The Urban thermal environment is influenced and modified in many ways. One modification is brought by the anthropogenic heat generation emitted from the combustion processes and the use of energy such as industrial, domestic and traffic procedure. The anthropogenic heat generation affect an the increase of urban temperature, the well-known urban heat islands. The study on the urban thermal environment needs a great deal of the statistic data about the inner-structure of urban, the contribution of different constructions and the traffic amount on urban thermal environment in finite region. In order to overtake a quantitative analysis of effect of the anthropogenic heat, a distribution map of the urban anthropogenic heat was made using hte data of the energy consumption used at the several constructions and traffic amount of vehicles in Pusan Metropolitan. Annual mean heat flux over the 4$\textrm{km}^2$ urbanized area in Pusan is 41.5W/$m^2$, ranging from 31.4W/$m^2$ in summertime to 59.5W/$m^2$ in wintertime and maximum diurnal anthropogenic heat generation is corresponding to 10% of irradiance during summertime.

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A note on Box-Cox transformation and application in microarray data

  • Rahman, Mezbahur;Lee, Nam-Yong
    • Journal of the Korean Data and Information Science Society
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    • v.22 no.5
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    • pp.967-976
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    • 2011
  • The Box-Cox transformation is a well known family of power transformations that brings a set of data into agreement with the normality assumption of the residuals and hence the response variable of a postulated model in regression analysis. Normalization (studentization) of the regressors is a common practice in analyzing microarray data. Here, we implement Box-Cox transformation in normalizing regressors in microarray data. Pridictabilty of the model can be improved using data transformation compared to studentization.

Visual Query and Analysis Tool of the Moving Object Database System

  • Lee, J.H.;Lee, S.H.;Nam, K.W.;Park, J.H.
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.455-457
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    • 2003
  • Diverse researches are working moving objects. The most important activities in a moving object database system are query and analysis of spatio -temporal data providing decision-making and problem solving support. Traditional spatial database query language and tools are inappropriate of the real world entities. This paper presents a spatio-temporal query and analysis tool with visual environment. It provides effective, interactive and user-friendly as well as statistic analysis. The moving objects database system stores plentiful moving objects data and performs spatio-temporal and nonspatio-temporal queries.

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The Effect of the Squat Exercise by Different Baseform on Balance Ability Enhancement in Normal Adult (선택적 지지면에 따른 스쿼트 운동이 정상 성인의 균형조절능력에 미치는 영향)

  • Kim, Minsoo;Seo, Inyoul;Jung, Gowoon;Lee, Geoncheol;Jung, Hanshin
    • Journal of The Korean Society of Integrative Medicine
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    • v.1 no.3
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    • pp.63-78
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    • 2013
  • PURPOSE : This study aims to investigate the positive correlation in pre-post test design between squat exercise on different baseform and the static/dynamic balance ability enhancement in adults. METHOD : This clinical study was designed into three different random-sampling adult groups (flat, balanced, vibration exercise device) and performed squat exercise. The static/dynamic balance ability was measured prior to the intervention and vice-versa. Balance was examined using the balance master 7.0 version systems. RESULT : 1) After the intervention, the controlled mat group in mCTSIB has showned the minimal mean value and the variation regards as acceptable by statistic value. 2) After the intervention, The mean value of LOS shows the minimal average variation in Randomised Trials, but the other two trials shows the maximal fluctuation. The difference variation regards as acceptable statistic value. 3)After the intervention, the mean value of mat group measrued as the maximal results, the difference variation regards as acceptable statistic value. 4)The striking correlation difference at mCTSIB has found in the vibration device exercise group, but LOS and Rhythmic W-S showed the correaltion in Mat group. CONCLUSION : The study found the positive correlation that enhanced balance ability on the different dynamic baseform squat exercise than static baseform environment. The significant difference found the balance pad squat effects on developing balance ability and the correlationship regards as statistically significant value.