scholarly journals National Physical Laboratory Radiocarbon Measurements IV

Radiocarbon ◽  
1966 ◽  
Vol 8 ◽  
pp. 340-347 ◽  
Author(s):  
W. J. Callow ◽  
M. J. Baker ◽  
Geraldine I. Hassall
Keyword(s):  
Standard Deviation ◽  
Standard Error ◽  
Half Life ◽  
Count Rate ◽  
National Physical Laboratory ◽  
Background Count ◽  
Best Value ◽  
Sample Count ◽  
The Difference ◽  
Absolute Age

The following list comprises measurements made since those reported in NPL III and is complete to the end of November 1965.Ages are relative to A.D. 1950 and are calculated using a half-life of 5568 yr. The measurements, corrected for fractionation (quoted δC13 values are relative to the P.D.B. standard), are referred to 0.950 times the activity of the NBS oxalic acid as contemporary reference standard. The quoted uncertainty is one standard deviation derived from a proper combination of the parameter variances as described in detail in NPL III. These variances are those of the standard and background measurements over a rolling twenty week period, of the sample δC14 and δC13 measurements and of the de Vries effect (assumed to add an additional uncertainty equivalent to a standard deviation of 80 yr). Any uncertainty in the half-life has been excluded so that relative C14 ages may be correctly compared. Absolute age assessments, however, should be made using the accepted best value for the half-life and the appropriate uncertainty then included. If the net sample count rate is less than 4 times the standard error of the difference between the sample and background count rates, a lower limit to the age is reported corresponding to a net sample count rate of 4 times the standard error of this difference.

scholarly journals National Physical Laboratory Radiocarbon Measurements II

Radiocarbon ◽  
1964 ◽  
Vol 6 ◽  
pp. 25-30 ◽  
Author(s):  
W. J. Callow ◽  
M. J. Baker ◽  
Daphne H. Pritchard
Keyword(s):  
Standard Deviation ◽  
Standard Error ◽  
Half Life ◽  
Research Programme ◽  
National Physical Laboratory ◽  
Reference Standard ◽  
Best Value ◽  
Physical Laboratory ◽  
The Difference ◽  
Absolute Age

The following list comprises measurements made since those reported in NPL I and is complete to the end of November 1963.Ages are relative to a.d. 1950 and are calculated using a half-life of 5568 yr. The measurements have been corrected for fractionation and referred to 0.950 times the activity of the NBS oxalic acid as a contemporary reference standard. The quoted uncertainty is one standard deviation derived from a proper combination of the parameter variances, viz. those of the standard and background measurements over a rolling twenty-week period, of the sample measurements from at least three independent fillings, of the δC13 measurements and of the de Vries effect (assumed to add an additional uncertainty equivalent to a standard deviation of 80 yr). Any uncertainty in the half-life has been excluded so that relative C14 ages may be correctly compared. Absolute age assessments, however, should be made using the accepted best value for the half-life and the appropriate uncertainty included. If the net sample activity is less than 4 times the standard error of the difference between the sample and background activities, a lower limit to the age is reported equivalent to a sample activity of 4 times the standard error of this difference.The description of each sample is based on information provided by the person submitting the sample to the Laboratory.The work reported forms part of the research programme of the Laboratory and is published by permission of the Director.

scholarly journals Reliable Change Formula Query: Temkin et al. reply

2000 ◽  
Vol 6 (3) ◽  
pp. 364-364 ◽  
Author(s):  
NANCY R. TEMKIN ◽  
ROBERT K. HEATON ◽  
IGOR GRANT ◽  
SUREYYA S. DIKMEN
Keyword(s):  
Standard Deviation ◽  
Standard Error ◽  
Direct Method ◽  
Single Point ◽  
Reliability Coefficient ◽  
Reliable Change Index ◽  
Square Root ◽  
Reliable Change ◽  
The Difference ◽  
The One

Hinton-Bayre (2000) raises a point that may occur to many readers who are familiar with the Reliable Change Index (RCI). In our previous paper comparing four models for detecting significant change in neuropsychological performance (Temkin et al., 1999), we used a formula for calculating Sdiff, the measure of variability for the test–retest difference, that differs from the one Hinton-Bayre has seen employed in other studies of the RCI. In fact, there are two ways of calculating Sdiff—a direct method and an approximate method. As stated by Jacobson and Truax (1991, p. 14), the direct method is to compute “the standard error of the difference between the two test scores” or equivalently [begin square root](s12 + s22 − 2s1s2rxx′)[end square root] where si is the standard deviation at time i and rxx′ is the test–retest correlation or reliability coefficient. Jacobson and Truax also provide a formula for the approximation of Sdiff when one does not have access to retest data on the population of interest, but does have a test–retest reliability coefficient and an estimate of the cross-sectional standard deviation, i.e., the standard deviation at a single point in time. This approximation assumes that the standard deviations at Time 1 and Time 2 are equal, which may be close to true in many cases. Since we had the longitudinal data to directly calculate the standard error of the difference between scores at Time 1 and Time 2, we used the direct method. Which method is preferable? When the needed data are available, it is the one we used.

scholarly journals The Effectiveness of Mix Impact Aerobic Gymnastics Exercises With SKJ 2000 On Improvement of Physical Freshness

2021 ◽  
Vol 12 (03) ◽  
pp. 39-44
Author(s):  
Anik Maryani ◽  
Fahmy Fachrezzy ◽  
Ramdan Pelana
Keyword(s):  
Standard Deviation ◽  
Physical Fitness ◽  
Aerobic Exercise ◽  
Standard Error ◽  
Exercise Group ◽  
Mean Value ◽  
Mean Difference ◽  
Final Test ◽  
The Mean ◽  
The Difference

This study aims to determine the effectiveness of the effect of aerobic mix impact and SKJ 2000 version (core exercise) to improve physical fitness in female students. The research was conducted at SMEA YASMA Sudirman Cijantung for 8 weeks with 24 meetings. The method used is an experimental method with a pre and post-test design. The sampling technique was random sampling from a total of 40 grade 1 students and 30 samples were taken. The data collection technique used was a physical fitness test using the Indonesian Physical Fitness Test (TKJI). Hypothesis testing uses the t-test at the significant level (α) 0.05. The results showed that the difference between the mean value of the initial test (x) and the final test (y) in the mixed impact aerobic exercise group was obtained = -6.47; the value of the standard deviation of the difference = 1,2; the standard error value of the mean difference = 0.32; and the value becomes = -20,2. The initial test (x) and the final test (y) in the 2000 version of the Physical Fitness exercise obtained the difference in the mean value is = -5; the value of the standard deviation of the difference = 1.1; the standard error value of the mean difference = 0.29; and the value becomes = -17.24. The final test of the mixed impact aerobic exercise group (x) and the final test of the aerobic exercise group (y) version 2000, obtained the mean value of the variable x = 19.33; variable value y = 17; the standard deviation value x = 1.48; standard deviation of the variable y = 2.31; standard error variable x = 0.4; standard error for the variable y = 0.62; standard error for the mean difference between x and variable = 0.74; Hypothesis test results obtained t observation = 3.15, at 28 degrees of freedom and a significant level (α) 0.05, the value of t table = 2.048 is obtained. The conclusion of the study is that the effect of mix impact aerobic exercise is more effective in improving physical fitness compared to those using the 2000 version of the fitness gymnastics version of aerobic exercise.

scholarly journals Radiocarbon Dating at the University of Washington III

Radiocarbon ◽  
1966 ◽  
Vol 8 ◽  
pp. 498-506 ◽  
Author(s):  
A. W. Fairhall ◽  
W. R. Schell ◽  
J. A. Young
Keyword(s):  
Standard Deviation ◽  
Oxalic Acid ◽  
Lower Limit ◽  
Half Life ◽  
Radiocarbon Dating ◽  
Isotope Fractionation ◽  
Statistical Error ◽  
Sample Count ◽  
The University ◽  
Made In

This date list consists of those measurements made since 1962. The counter is one described previously (Fairhall and Schell, 1963). The results are computed using NBS oxalic acid as the standard and 5568 for the half-life of C14. Standard deviations are computed for each measurement, including the statistical error in the sample count and uncertainties in background and standard. In general, each sample is counted at least twice. The quoted error on the date is the standard deviation. A 2σ criterion is used to establish a lower limit to the age of very old samples with no detectable trace of C14. No correction for isotope fractionation has been made in any of the measurements.

scholarly journals Institute of Geological Sciences Radiocarbon Dates II

Radiocarbon ◽  
1972 ◽  
Vol 14 (1) ◽  
pp. 140-144 ◽  
Author(s):  
E. Welin ◽  
L. Engstrand ◽  
S. Vaczy
Keyword(s):  
Standard Deviation ◽  
Standard Error ◽  
Half Life ◽  
Radiocarbon Dates ◽  
Geological Sciences

This date list was compiled by the Institute of Geological Sciences (U.K.) incorporating data supplied under contract by E. Welin, Radioactive Dating Laboratory, Stockholm. Unless otherwise stated, age figures are in C14 years before A.D. 1950. The half-life of C14 is taken as 5568 and the standard error is given as a standard deviation of 1σ. Correction for C13/C12 has not been made.

scholarly journals Birmingham University Radiocarbon Dates V

Radiocarbon ◽  
1971 ◽  
Vol 13 (2) ◽  
pp. 141-156 ◽  
Author(s):  
F. W. Shotton ◽  
R. E. G. Williams
Keyword(s):  
Statistical Analysis ◽  
Standard Deviation ◽  
Sample Size ◽  
Half Life ◽  
Background Count ◽  
Radiocarbon Dates

The following list comprises results obtained during 1970 from both the 1 L and 6 L counters. Results are not corrected for C13fractionation. Errors quoted refer only to the standard deviation calculated from a statistical analysis of sample and background count rates and the Libby half-life of 5570 ± 30 yr. Pretreatment has been continued as described previously (R., 1969, v. 11, p. 263). In cases where sample size was insufficient for full pretreatment, details of the necessary deviations accompany the result.

scholarly journals Birmingham University Radiocarbon Dates II

Radiocarbon ◽  
1968 ◽  
Vol 10 (2) ◽  
pp. 200-206 ◽  
Author(s):  
F. W. Shotton ◽  
D. J. Blundell ◽  
R. E. G. Williams
Keyword(s):  
Statistical Analysis ◽  
Standard Deviation ◽  
Proportional Counter ◽  
Half Life ◽  
Background Count ◽  
Radiocarbon Dates ◽  
Double Ring

Measurements have continued with the 6 L counter which has proved reliable at pressures as high as 2.6 atm and as low as 0.3 atm. It has now been enclosed in a double ring of 27 geiger tubes which has reduced the background count to 10 cpm at 2 atm. So far, we have had no success with the 1.5 L Oeschger-type proportional counter. Failure to obtain steady readings is probably due to continued outgassing from the teflon insulation. All insulating parts have now been remanufactured from the same source of teflon as was used in the 6 L counter, and the Oeschger counter is being reassembled.Results are still given without correction for δC13. Errors quoted refer only to the standard deviation calculated from a statistical analysis of count rates and the Libby half-life of 5570 ± 30 yr.

scholarly journals Model for Predicting and Analyzing the %Fe Removed as Deleterious Element from Al-Si alloys During Fe Removal Processing with Mn

2016 ◽  
Vol 2 (6) ◽  
pp. 125
Author(s):  
F. A. Anene ◽  
N. E. Nwankwo
Keyword(s):  
Standard Deviation ◽  
Standard Error ◽  
Model Equation ◽  
Processing Parameters ◽  
Holding Time ◽  
Experimental Result ◽  
Close Proximity ◽  
Mn Content ◽  
The Difference ◽  
Cubic Function

Model equation for predicting and analysing %Fe removed from a eutectic Al-Si alloy during Fe removal processing with Mn under controlled conditions has been derived and validated. The model derived;%Fe removed = +1.30700 + 0.095882* Al-Si + %Mn - 0.068512* Al-Si + %Mn^2 + 9.77000E-003* Al-Si+%Mn^3 ,is found to predict the %Fe removed from Al-Si alloy as a cubic function of Mn content. With a standard deviation of 0.010. Analysed results obtained show that %Fe removal equation with Mn addition has been validly derived. The model " R-Squared" of 0.9814 is found to be in agreement with the "Adj R-Squared" of 0.9628; the difference being less than 0.2. The derived model equation gives a reasonable forecast of %Fe removed very close to the values obtained from the experiments. The close proximity of both model and experimental result values is attributed to the low standard error of the model coefficients. The processing parameters are process temperature, alloy contents and holding time.

scholarly journals Institute of Geological Sciences Radiocarbon Dates I

Radiocarbon ◽  
1971 ◽  
Vol 13 (1) ◽  
pp. 26-28 ◽  
Author(s):  
E. Welin ◽  
L. Engstrand ◽  
S. Vaczy
Keyword(s):  
Standard Deviation ◽  
Standard Error ◽  
Half Life ◽  
Radiocarbon Dates ◽  
Geological Sciences

This date list was compiled by the Institute of Geological Sciences (U.K.) incorporating data supplied under contract by Dr. E. Welin, Radioactive Dating Laboratory, Stockholm. Unless otherwise stated age figures are in C14 years before A.D. 1950. The half-life of C14 is taken as 5568 years and the standard error is given as a standard deviation of 1σ. Correction for C13/C12 has not been made. This is the first of a series of annotated lists of C14 dates of British and overseas material in course of preparation by the Institute.

scholarly journals Birmingham University Radiocarbon Dates IV

Radiocarbon ◽  
1970 ◽  
Vol 12 (2) ◽  
pp. 385-399 ◽  
Author(s):  
F. W. Shotton ◽  
D. J. Blundell ◽  
R. E. G. Williams
Keyword(s):  
Statistical Analysis ◽  
Standard Deviation ◽  
Half Life ◽  
Background Count ◽  
Radiocarbon Dates

Measurements have continued with both the 1 L and 6 L counters. Results are not corrected for C13 fractionation. Errors quoted refer only to the standard deviation calculated from a statistical analysis of sample and background count rates and the Libby half-life of 5570 ± 30 yr. Pretreatment has been continued as described previously (Shotton, Blundell, and Williams, 1969).

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