• Title/Summary/Keyword: standard error

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An Analysis of Performance Error of High Precision Measuring Instrument (진원도 측정기의 오차특성에 관한 연구)

  • 한응교;노병옥;허민석
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.13 no.5
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    • pp.862-874
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    • 1989
  • A phase evil method and spectrum analysis were instrument error which is originated from measurement system and the form error of standard specimens. An instrument with a rotating table supported by an air bearing is calibrated using standard specimens. The phase of standard specimens was measured 12 times on the rotating table with rotating 30 in turn and its measurement magnification was set by 100000 times. As a result of data analysis of all the observations, read out at each of 144 orientations(per 2.5) from recorded datafiles, the error of the performance of the instrument and those of the standard specimens are evaluated and a systematic deviation of the instrument is determined. In the particular instrument used in the present experiment, the deviation of the instrument is determined with the accuracy of 15nm and those of standard specimens with the accuracy of 23, 13 n, respectively. The reproducibility of the instrument is investigated, too. If the instrument is calibrated by using the above standard specimens, then the accuracy of the measurement of roundness error can be improved to about 15nm.

Standard Error of Empirical Bayes Estimate in NONMEM$^{(R)}$ VI

  • Kang, Dong-Woo;Bae, Kyun-Seop;Houk, Brett E.;Savic, Radojka M.;Karlsson, Mats O.
    • The Korean Journal of Physiology and Pharmacology
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    • v.16 no.2
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    • pp.97-106
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    • 2012
  • The pharmacokinetics/pharmacodynamics analysis software NONMEM$^{(R)}$ output provides model parameter estimates and associated standard errors. However, the standard error of empirical Bayes estimates of inter-subject variability is not available. A simple and direct method for estimating standard error of the empirical Bayes estimates of inter-subject variability using the NONMEM$^{(R)}$ VI internal matrix POSTV is developed and applied to several pharmacokinetic models using intensively or sparsely sampled data for demonstration and to evaluate performance. The computed standard error is in general similar to the results from other post-processing methods and the degree of difference, if any, depends on the employed estimation options.

A Note on the Decision of Sample Size by Relative Standard Error in Successive Occasions (계속조사에서 상대표준오차를 이용한 표본크기 결정에 관한 고찰)

  • Han, GeunShik;Lee, Gi-Sung
    • The Korean Journal of Applied Statistics
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    • v.28 no.3
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    • pp.477-483
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    • 2015
  • This study deals with the decision problem of sample size by the relative standard error of estimates derived from survey results in successive occasions. The population of the construction in business survey results is used to calculate quartile of the relative standard error of the 1,000 sample obtained from simple or stratified random sampling. The sample size at time t with a relative standard error of the point (t-1) in the successive occasions were calculated according to the sampling method. As a result, in terms of the sample size according to the size of the relative standard error of the (t-1), simple random sampling differs significantly from stratified sampling. In addition, we could see differences in sample size (depending on how the population is stratified) and that careful attention is required in the problem of sample size by the relative standard error of estimates derived from survey results in successive occasions.

Precision Control of a Torque Standard Machine Using Fuzzy Controller (퍼지제어기를 이용한 토크 표준기의 정밀제어)

  • Kim, Gab-Soon;Kang, Dae-Im
    • Journal of the Korean Society for Precision Engineering
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    • v.18 no.7
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    • pp.46-52
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    • 2001
  • This study describes the precision control of the torque standard machine using a self-tuning fuzzy controller. The torque standard machine should generate the accurate torque for calibrating a torque sensor. In order to reduce the relative expanded uncertainty of the torque standard machine, when a weight is hanged to the end of the torque arm for generating the torque, the sloped torque arm should be accurately controlled to the horizontal level. If the slope of the torque arm is larger from the inaccurate control, the uncertainty of the torque standard machine due to control will be larger. This applies the inaccurate torque to a torque sensor to calibrate, and the measuring error of the torque sensor generate from it. Therefore the torque arm of the torque standard machine is accurately controlled. In this paper, the self-tuning fuzzy controller was designed using a fuzzy theory, and the torque arm of the torque standard machine was accurately controlled. The control gain of the fuzzy controller, that is the membership function size of the error, the membership function size of the error change and the membership function size of the controller were determined from the self-tuning. The control results of the torque standard machine were the overshoot within 0.0076mm, the rise time within 16.70sec and the steady state error within 0.0076mm.

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HIERARCHICAL ERROR ESTIMATORS FOR LOWEST-ORDER MIXED FINITE ELEMENT METHODS

  • Kim, Kwang-Yeon
    • Korean Journal of Mathematics
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    • v.22 no.3
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    • pp.429-441
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    • 2014
  • In this work we study two a posteriori error estimators of hierarchical type for lowest-order mixed finite element methods. One estimator is computed by solving a global defect problem based on the splitting of the lowest-order Brezzi-Douglas-Marini space, and the other estimator is locally computable by applying the standard localization to the first estimator. We establish the reliability and efficiency of both estimators by comparing them with the standard residual estimator. In addition, it is shown that the error estimator based on the global defect problem is asymptotically exact under suitable conditions.

The efficiency analysis of TIN construction considering DEM standard error (DEM 표준오차를 고려한 TIN 구축의 효용성 분석에 관한 연구)

  • 이근상;채효석;조기성
    • Spatial Information Research
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    • v.11 no.1
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    • pp.23-32
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    • 2003
  • TIN is applied in pondage calculation and topography analysis. And much processing time and storage capacity are needed because TIN contains information as elevation, slope and aspect. In the construction of TIN using contour, weed tolerance that is used for the simplification of line is influenced on the sampling distance of contour. The processing time and storage capacity of TIN are calculated in according to the weed tolerance of various size in this research. And we estimated OEMs standard error that is created from TIN to present reasonable weed tolerance and decided the size of weed tolerance that satisfy DEM standard error. We got TINs weed tolerance that satisfy DEM standard error(5m) was 70m and DEMs resolution is 20m as estimation result.

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Studies on Serum Chemical Values of Holstein Cows (Holstein 암소 혈청(血淸)의 화학성분(化學成分)에 관(關)하여)

  • Moon, Hi Cheol
    • Korean Journal of Veterinary Research
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    • v.14 no.2
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    • pp.173-177
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    • 1974
  • Thirty of healthy non-pregnant Holstein cows being raised in the vicinity of Daejeon, which had been delivered of calves 4 to 6 times since they were imported to Korea, were selected with the purpose of serum chemical analysis. Total protein, albumin, globulin, total cholesterol, urea nitrogen and glucose and A/G ratio were investigated. The results of present investigation were summarized as follows: 1. Ranges and mean values (with standard error) of total protein, albumin and globulin were 6.87~8.58g/100ml, $7.75{\pm}0.60g/100ml$; 2.6~3.5g/100ml(37.1~45.0%), $3.26{\pm}0.27g/100ml$(40.1%); and 3.78~5.48g/100ml(55.1~64.6%), $4.51{\pm}0.43g/100ml$(58.1%), respectively. 2. Range and mean value (with standard error) of A/G ratio were 0.52~0.86 and 0.73~0.093. 3. Range and mean value (with standard error) of glucose were 35~50mg/100ml and $45.2{\pm}9.1mg/100ml$. 4. Range and mean value(with standard error) of total cholesterol were 122~228mg/100ml and $194.6{\pm}11.1mg/100ml$. 5. Serum urea nitrogen showed that the range of 10.5~15.1mg/100ml and the mean value(with standard error) of $12.7{\pm}1.5mg/100ml$.

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Model Selection for Tree-Structured Regression

  • Kim, Sung-Ho
    • Journal of the Korean Statistical Society
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    • v.25 no.1
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    • pp.1-24
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    • 1996
  • In selecting a final tree, Breiman, Friedman, Olshen, and Stone(1984) compare the prediction risks of a pair of tree, where one contains the other, using the standard error of the prediction risk of the larger one. This paper proposes an approach to selection of a final tree by using the standard error of the difference of the prediction risks between a pair of trees rather than the standard error of the larger one. This approach is compared with CART's for simulated data from a simple regression model. Asymptotic results of the approaches are also derived and compared to each other. Both the asymptotic and the simulation results indicate that final trees by CART tend to be smaller than desired.

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On-Site Evaluation Technique of Current Transformer Comparator System (전류변성기 비교측정 장치의 현장 평가기술)

  • Jung, Jae-Kap;Lee, Sang-Hwa;Kwon, Sung-Won;Kang, Jeon-Hong;Kim, Myung-Soo
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.56 no.5
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    • pp.926-932
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    • 2007
  • A recently developed methods for on-site calibration of the current transformer (CT) comparator system have been reviewed in the paper. The method utilizes several traveling standards, which consist of the CT, non-reactive standard resistors, wide ratio error CT, and shunt resistors. The traveling CT is used for absolute evaluation of a standard CT belonging to industry. The non-reactive standard resistors and a wide ratio error CT are used for the linearity check of errors in the current comparator. The shunt resistors are used for evaluation of CT burden of industry.

Construction of On-Site Calibration Facilities of 66 kV Voltage Transformer Comparator System (66kV급 전압변성기 비교측정 장치의 현장 평가설비 구축)

  • Jung, Jae-Kap;Lee, Sang-Hwa;Kwon, Sung-Won;Kim, Myung-Soo
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.56 no.7
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    • pp.1268-1274
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    • 2007
  • A recently developed methods for the on-site calibration of the voltage transformer (VT) comparator system have been reviewed in the paper. The method utilizes the several traveling standards consisting of the VT, the non-reactive standard resistors, the wide ratio error VT, and the decade resistors. The VT is used for the absolute evaluation of a standard VT belonging to the industry. The non-reactive standard resistor and wide ratio error VT are used for the linearity check of errors in the voltage comparator of the industry. The decade resistors are used for evaluation of a VT burden of the industry.