A fixed point computation of partial correlation coefficients in linear prediction

2005 ◽  
Author(s):  
J. Le Roux ◽  
C. Gueguen
Keyword(s):  
Fixed Point ◽  
Partial Correlation ◽  
Linear Prediction ◽  
Correlation Coefficients ◽  
Fixed Point Computation

Linear prediction error filter design

Geophysics ◽  
1981 ◽  
Vol 46 (6) ◽  
pp. 875-879 ◽  
Author(s):  
S. T. Hildebrand
Keyword(s):  
Prediction Error ◽  
Partial Correlation ◽  
Linear Prediction ◽  
Filter Design ◽  
Moving Average ◽  
Variational Calculus ◽  
Correlation Coefficients ◽  
Normal Equations ◽  
Step Procedure ◽  
Simple Phase

The design of a linear prediction error filter can be formulated as a four‐step procedure. These steps, in part, consist of a variational calculus approach that leads directly to the normal equations and an entropy conservation principle. From the normal equations, we obtain parameters called partial correlation coefficients that minimize the prediction error at the kth filter design step. Partial correlation coefficients determine the best prediction error filter for different seismic trace models (autoregressive, autoregressive‐moving average, and phase‐intercept‐shifted autoregressive traces). A result shows that simple phase distortion can increase the length of the prediction error filter and affect the estimates of the reflection sequence.

scholarly journals The First National Survey of Cadmium in Cacao Farm Soil in Colombia

Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 761
Author(s):  
Daniel Bravo ◽  
Clara Leon-Moreno ◽  
Carlos Alberto Martínez ◽  
Viviana Marcela Varón-Ramírez ◽  
Gustavo Alfonso Araujo-Carrillo ◽  
...  
Keyword(s):  
Graphical Models ◽  
Partial Correlation ◽  
National Level ◽  
Prediction Method ◽  
Correlation Coefficients ◽  
Predictive Performance ◽  
Nationwide Survey ◽  
Critical Discussion ◽  
Cadmium Content ◽  
Soil Variables

This study represents the first nationwide survey regarding the distribution of Cd content in cacao-growing soils in Colombia. The soil Cd distribution was analyzed using a cold/hotspots model. Moreover, both descriptive and predictive analytical tools were used to assess the key factors regulating the Cd concentration, considering Cd content and eight soil variables in the cacao systems. A critical discussion was performed in four main cacao-growing districts. Our results suggest that the performance of a model using all the variables will always be superior to the one using Zn alone. The analyzed variables featured an appropriate predictive performance, nonetheless, that performance has to be improved to develop a prediction method that might be used nationwide. Results from the fitted graphical models showed that the largest associations (as measured by the partial correlation coefficients) were those between Cd and Zn. Ca had the second-largest partial correlation with Cd and its predictive performance ranked second. Interestingly, it was found that there was a high variability in the factors correlated with Cd in cacao growing soils at a national level. Therefore, this study constitutes a baseline for the forthcoming studies in the country and should be reinforced with an analysis of cadmium content in cacao beans.

SERUM GONADOTROPHINS, TESTOSTERONE AND SPERMATOGENESIS IN SUBFERTILE MEN

1977 ◽  
Vol 86 (3) ◽  
pp. 651-658 ◽  
Author(s):  
J. H. Aafjes ◽  
J. C. M. van der Vijver ◽  
R. Docter ◽  
P. E. Schenck
Keyword(s):  
Partial Correlation ◽  
Sperm Count ◽  
Correlation Coefficients ◽  
Serum Levels ◽  
Significant Negative Correlation ◽  
The Other ◽  
Sperm Production ◽  
Positive Correlation ◽  
Natural Logarithm ◽  
Biopsy Score

ABSTRACT In 210 subfertile men there existed a significant positive correlation between serum FSH and LH (0.41). No correlation was observed between the gonadotrophin levels and testosterone. In contrast to this FSH as well as LH were negatively correlated with the natural logarithm (In) of the sperm count/ml ejaculate (−0.44 and −0.18, respectively). When the positive correlation which existed between FSH and LH was used to calculate partial correlation coefficients, the coefficient between FSH and ln sperm count did hardly change (−0.41) the coefficient between LH and ln sperm count on the other hand became insignificant (−0.05). This suggests that spermatogenesis influences FSH serum levels in subfertile men by a decreased suppression when sperm production is diminished. Testicular biopsies taken from 97 of these patients were used to determine biopsy scores. These scores showed a significant negative correlation with FSH (−0.34) and a positive one with ln sperm count/ml ejaculate (0.45). Interestingly the biopsy score of 16 patients who fertilized their wives, was found to be higher compared with the score of the other patients who did not fertilize. The number of sperm/ml ejaculate and the FSH values of these 2 groups of biopsied patients were, however, not significantly different. This leads to the conclusion that the biopsy score is a better parameter for the evaluation of oligospermic men than either sperm count or FSH serum values.

scholarly journals Pre-service Science and Mathematics Teachers’ Teaching Efficacy Beliefs and Attitudes toward Teaching: A Partial Correlation Research

2020 ◽  
Vol 45 (9) ◽  
pp. 42-61
Author(s):  
Busra Kartal ◽  
Keyword(s):  
Mathematics Teachers ◽  
Elementary Science ◽  
Partial Correlation ◽  
Correlation Coefficients ◽  
Efficacy Beliefs ◽  
Positive Attitudes ◽  
And Mathematics ◽  
High Level ◽  
Science And Mathematics Teachers ◽  
Beliefs And Attitudes

Teachers with a high level of self-efficacy and positive attitudes are more likely to use new and constructivist approaches and to create a learning environment in which students may develop 21st-century skills. Examining pre-service teachers’ attitudes and beliefs related to teaching allow teacher preparation programs to evaluate their effectiveness on beliefs and attitudes. This correlational research investigated pre-service elementary science and mathematics teachers’ beliefs and attitudes due to gender, grade level, and department, and revealed the reliable correlation between beliefs and attitudes performing partial correlation. Results show that females feel more efficacious in teaching and have more positive attitudes than males. 4th grades also perceive a higher level of efficacy for student engagement and using instructional strategies than 1st grades. Partial correlation coefficients revealed positive strong relationships between attitudes and efficacy beliefs. Recommendations are suggested based on implications.

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