Testing the Mean Vector and the Correlation Coefficient in Life-Testing Under Bivariate Normality

2007 ◽  
Vol 32 (8) ◽  
pp. 899-913 ◽  
Author(s):  
M. L. Tiku ◽  
P. S. Gill
Keyword(s):  
Correlation Coefficient ◽  
Life Testing ◽  
The Mean ◽  
Mean Vector ◽  
Bivariate Normality

POWER PROPERTIES OF THE T2 CONTROL CHART

1995 ◽  
Vol 02 (01) ◽  
pp. 1-14 ◽  
Author(s):  
SIEBRAND J. WIERDA ◽  
TON STEERNEMAN
Keyword(s):  
Covariance Matrix ◽  
Correlation Coefficient ◽  
Control Chart ◽  
Bivariate Case ◽  
Control Situation ◽  
The Mean ◽  
The Impact ◽  
T2 Control Chart ◽  
Mean Vector ◽  
Over Time

The T2 control chart is a multivariate SPC tool that monitors the mean vector of a process and that examines whether it remains stable over time. This paper examines the probability that the T2 control chart signals for an out-of-control situation. This probability is called the power of the chart. We study the effect on the power consequent on a change in the sample sizes, the dimension, or the level. For the bivariate case, we consider the impact on the power consequent on a change in the correlation coefficient. Finally, we examine what happens if the assumption that the covariance matrix is stable over time is violated.

THE EFFECT OF ALTERATION OF THYROXINE BINDING CAPACITY ON THE DIALYZABLE AND ABSOLUTE FRACTIONS OF TRIIODOTHYRONINE IN CIRCULATION

1973 ◽  
Vol 72 (2) ◽  
pp. 265-271 ◽  
Author(s):  
J. H. Dussault ◽  
D. A. Fisher ◽  
J. T. Nicoloff ◽  
V. V. Row ◽  
R. Volpe
Keyword(s):  
Correlation Coefficient ◽  
Inverse Relationship ◽  
Binding Capacity ◽  
Hormone Concentration ◽  
Thyroxine Binding Globulin ◽  
Serum Thyroxine ◽  
A Value ◽  
The Mean ◽  
Male Subjects ◽  
Female Subjects

ABSTRACT In order to determine the effect of alterations in binding capacity of thyroxine binding globulin (TBG) on triiodothyronine (T3) metabolism, studies were conducted in 10 patients with idiopathically low (7 subjects) or elevated (3 subjects) TBG levels and 10 subjects given norethandrolone (7 male subjects) or oestrogen (3 female subjects). Measurements of serum thyroxine (T4) concentration, maximal T4 binding capacity, serum T3 concentration and per cent dialyzable T3 were conducted. Serum T3 was measured both by chemical and radioimmunoassay methods. In patients with idiopathically low TBG, the mean serum T4 concentration was low (2.4 μg/100 ml), the mean serum T3 level low (55 ng/100 ml), the mean per cent dialyzable T3 increased (0.52%), and the calculated free T3 concentration normal (186 pg/100 ml). In patients with idiopathically high TBG levels the mean T4 concentration was high (10.3 μg/100 ml), the mean T3 level slightly elevated (127 ng/100 ml), the% dialyzable T3 low (0.10%) and the calculated free T3 concentration low normal (123 pg/100 ml). The correlation coefficient between the per cent dialyzable T3 and maximal TBG binding capacity in the 20 subjects was 0.68, a value significant at the P < 0.01 level. Thus, alterations in binding capacity of TBG seem to influence T3 and T4 metabolism similarly; the inverse relationship between the % of dialyzable hormone and total hormone concentration tends to keep the absolue levels of free hormones stable.

scholarly journals Effect of Posterior Tibial Slope Change on Postoperative Range of Motion and Clinical Outcomes after Posterior Cruciate-Substituting Total Knee Arthroplasty

2021 ◽  
Author(s):  
O-Sung Lee ◽  
Jangyun Lee ◽  
Myung Chul Lee ◽  
Hyuk-Soo Han
Keyword(s):  
Total Knee Arthroplasty ◽  
Range Of Motion ◽  
Correlation Coefficient ◽  
Knee Arthroplasty ◽  
Tibial Slope ◽  
Posterior Tibial Slope ◽  
Posterior Tibial ◽  
Clinical Scores ◽  
Total Knee ◽  
The Mean

AbstractThe posterior tibial slope (PTS) is usually adjusted by less than 5 degrees, without considering its individual difference, during posterior cruciate-substituting (PS) total knee arthroplasty (TKA). The effect of these individual changes of PTS would be important because clinical results depending on postoperative PTS were reported conflictingly. We investigated the effect of the change in PTS on the postoperative range of motion (ROM) and clinical scores after PS TKA. We retrospectively reviewed 164 knees from 107 patients who underwent PS TKA with a 2-year follow-up. We analyzed the preoperative and postoperative PTS, ROM, visual analog scale pain scale, Western Ontario and McMaster University Index (WOMAC), Hospital for Special Surgery Knee Score, Knee Society Score, and Forgotten Joint Score (FJS). The association of the absolute change in PTS with ROM and clinical scores was analyzed using correlation analysis and multiple regression analysis. As a result, the mean PTS and mean ROM changed from 9.6 ±  3.4 and 120.1 ±  15.4 degrees preoperatively to 2.0 ±  1.3 and 128.4 ±  9.3 degrees postoperatively, and the mean PTS change was 7.6 ±  3.5 degrees. The PTS change had no statistically significant association with the postoperative ROM and clinical scoring systems, although it did have a weak positive correlation with WOMAC function, No 10 (difficulty in rising from sitting) (correlation coefficient = 0.342, p = 0.041), and moderate positive correlation with the FJS, No. 6 (awareness when climbing stairs) (correlation coefficient = 0.470, p = 0.001). The authors concluded that the amount of change in PTS did not affect the postoperative ROM and clinical scores, although proximal tibial resection with a constant target of PTS resulted in individually different changes in the PTS after PS TKA,

Tests for the mean vector under intraclass covariance structure

1981 ◽  
Vol 12 (3-4) ◽  
pp. 237-245 ◽  
Author(s):  
Bernard Clement ◽  
Sukharanyan Chakraborty ◽  
Bimal K. Sinha ◽  
Narayan C. Giri
Keyword(s):  
Covariance Structure ◽  
The Mean ◽  
Mean Vector

scholarly journals BAYESIAN INFERENCE FOR THE TANGENT PORTFOLIO

2018 ◽  
Vol 21 (08) ◽  
pp. 1850054 ◽  
Author(s):  
DAVID BAUDER ◽  
TARAS BODNAR ◽  
STEPAN MAZUR ◽  
YAREMA OKHRIN
Keyword(s):  
Bayesian Inference ◽  
Point Of View ◽  
Posterior Distributions ◽  
Conditional Distributions ◽  
Linear Combinations ◽  
Conjugate Priors ◽  
Mean And Variance ◽  
The Mean ◽  
Stochastic Representations ◽  
Mean Vector

In this paper, we consider the estimation of the weights of tangent portfolios from the Bayesian point of view assuming normal conditional distributions of the logarithmic returns. For diffuse and conjugate priors for the mean vector and the covariance matrix, we derive stochastic representations for the posterior distributions of the weights of tangent portfolio and their linear combinations. Separately, we provide the mean and variance of the posterior distributions, which are of key importance for portfolio selection. The analytic results are evaluated within a simulation study, where the precision of coverage intervals is assessed.

Pyridoxine Deficiency After Solid Organ Transplant

2017 ◽  
Vol 27 (3) ◽  
pp. 251-256
Author(s):  
Summer Van Arsdale ◽  
Sarah E. Yost ◽  
Chiu-Hsieh Hsu ◽  
Mary Meer ◽  
Shari Schoentag ◽  
...  
Keyword(s):  
Correlation Coefficient ◽  
Solid Organ Transplantation ◽  
Organ Transplant ◽  
Multivariate Logistic Regression Analysis ◽  
Study Cohort ◽  
Solid Organ ◽  
Immune Functions ◽  
Pyridoxine Deficiency ◽  
The Mean ◽  
Low Levels

Objective: Pyridoxine is 1 of 8 B vitamins that assist in a variety of essential functions including immune functions. The purpose of this study was to assess the risk factors associated with low pyridoxine levels in solid organ transplantation recipients. Design: The study cohort was divided into 2 groups: (a) patients with normal pyridoxine levels or (b) patients with low pyridoxine levels. Dietary evaluation and clinical characteristics of all patients, rejection episodes, and immunosuppression were collected. Simple descriptive statistics were used to analyze the overall cohort. Results: Of the 48 patients, 29 (60%) in the study cohort were identified to have low pyridoxine levels. The mean interval between transplantation and pyridoxine level check was 910 days (standard deviation [SD] 456). The mean weight at the time of dietary consultation was 80 kg (SD 20.7). More patients in the deficient group received thymoglobulin for rejection treatment (56% vs 0%; P = .01) and were thymoglobulin recipients (78% vs 10%; odds ratio [OR] = 31.5; 95% confidence interval [CI], 2.35-422.30; P < .01). A strong correlation was identified between thymoglobulin treatment for induction and a low level of pyridoxine (correlation coefficient R = 0.6, P = .004) and between thymoglobulin treatment for rejection and a low pyridoxine level (correlation coefficient R = 0.5, P = .05). Based on multivariate logistic regression analysis, only thymoglobulin treatment (induction or rejection treatment) was significantly associated with low pyridoxine levels (OR = 19.5, 95% CI, 1.01-375.24; P < .05). Conclusions: Low levels of pyridoxine appear to be relatively common, and thymoglobulin treatments are associated with low pyridoxine levels. Prospective studies are needed to confirm and valuate the significance of these findings.

scholarly journals Evaluation of Genetic behavior of Sunflower (Helianthus annuus L.) As Effect by Planting Dates

2019 ◽  
Vol 9 (1) ◽  
pp. 150-155
Author(s):  
Abdullah F. Serheed ◽  
Haider T. Hussein
Keyword(s):  
Helianthus Annuus ◽  
Correlation Coefficient ◽  
Environmental Conditions ◽  
Genetic Variance ◽  
Planting Dates ◽  
Environmental Variance ◽  
Growing Seasons ◽  
The Mean ◽  
Phenotypic Variations ◽  
Coefficient Stability

Afield experiment was carried out during the spring and autumn seasons of 2016 and 2017 in AL- Musaib city / 40 km north of Babylon Provence. Two hybrids of sunflower( shamus, French hybrid (Euroflor) were used to evaluate the performance of the two cultivars at both growing seasons as well as knowledge of genetic behavior by studying the genetic and phenotypic variations, heritability percent, genetic and phenotypic coefficient, stability and persistence of the two cultivars .The results showed significant differences of the studied traits, as the genetic genotype (Shamus) most of the characteristics, especially in yield for two seasons.The genetic variance was higher than the environmental variance for the two seasons indicating that the two cultivars followed the same behavior. The heritability percent the dominant sense was high for most of the traits. The genetic and phenotypic variations between the mean and the high were different for the two seasons, the correlation coefficient was significant, for both cultivars, indicating the appropriateness of the two genotypes for the country's environmental conditions.

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