scholarly journals Robustness analysis of geodetic networks in the case of correlated observations

2013 ◽  
Vol 19 (3) ◽  
pp. 434-451
Author(s):  
Mevlut Yetkin ◽  
Mustafa Berber ◽  
Cevat Inal
Keyword(s):  
High Reliability ◽  
Robustness Analysis ◽  
Correlation Coefficients ◽  
Deformation Monitoring ◽  
Internal Reliability ◽  
Mathematical Relation ◽  
Multiple Correlation Coefficients ◽  
Gnss Networks ◽  
Reliability Numbers ◽  
Gps Observations

GPS (or GNSS) networks are invaluable tools for monitoring natural hazards such as earthquakes. However, blunders in GPS observations may be mistakenly interpreted as deformation. Therefore, robust networks are needed in deformation monitoring using GPS networks. Robustness analysis is a natural merger of reliability and strain and defined as the ability to resist deformations caused by the maximum undetecle errors as determined from internal reliability analysis. However, to obtain rigorously correct results; the correlations among the observations must be considered while computing maximum undetectable errors. Therefore, we propose to use the normalized reliability numbers instead of redundancy numbers (Baarda's approach) in robustness analysis of a GPS network. A simple mathematical relation showing the ratio between uncorrelated and correlated cases for maximum undetectable error is derived. The same ratio is also valid for the displacements. Numerical results show that if correlations among observations are ignored, dramatically different displacements can be obtained depending on the size of multiple correlation coefficients. Furthermore, when normalized reliability numbers are small, displacements get large, i.e., observations with low reliability numbers cause bigger displacements compared to observations with high reliability numbers.

Stepwise Regression Arithmetic and its Application on Slope Safety Monitoring

2012 ◽  
Vol 204-208 ◽  
pp. 2859-2864
Author(s):  
Lan Chen ◽  
Bang Bin Wu ◽  
Jing Yang Liu
Keyword(s):  
Stepwise Regression ◽  
Correlation Coefficients ◽  
Safety Monitoring ◽  
Deformation Monitoring ◽  
Slope Deformation ◽  
Statistical Regression ◽  
Multiple Correlation ◽  
High Slope ◽  
Multiple Correlation Coefficients ◽  
Good Agreement

Considering the effect of time, rainfall and temperature on slope deformation, deformation factors and expressions were deeply analyzed. Statistical regression model of slope deformation was established by Matlab software and stepwise regression algorithm, thus slope deformation can be regression analyzed and predicted. Through analyzing the deformation monitoring data of a hydropower station spillway left high slope, the result showed that statistical regression values of slope deformation are in good agreement with measured values, multiple correlation coefficients were good and the residual standard deviations were small. This model can reflect slope deformation and trend. It provided guidelines to analyze on security status and prediction of deformation trend with great practical value.

scholarly journals Is there a relationship between the overhead press and split jerk maximum performance? Influence of sex

2021 ◽  
pp. 174795412110204
Author(s):  
Marcos A Soriano ◽  
G Gregory Haff ◽  
Paul Comfort ◽  
Francisco J Amaro-Gahete ◽  
Antonio Torres-González ◽  
...  
Keyword(s):  
Confidence Intervals ◽  
Body Mass ◽  
Upper Limb ◽  
High Reliability ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Training Experience ◽  
Maximum Performance ◽  
Repetition Maximum ◽  
Intraclass Correlation Coefficients

The aims of this study were to (I) determine the differences and relationship between the overhead press and split jerk performance in athletes involved in weightlifting training, and (II) explore the magnitude of these differences in one-repetition maximum (1RM) performances between sexes. Sixty-one men (age: 30.4 ± 6.7 years; height: 1.8 ± 0.5 m; body mass 82.5 ± 8.5 kg; weightlifting training experience: 3.7 ± 3.5 yrs) and 21 women (age: 29.5 ± 5.2 yrs; height: 1.7 ± 0.5 m; body mass: 62.6 ± 5.7 kg; weightlifting training experience: 3.0 ± 1.5 yrs) participated. The 1RM performance of the overhead press and split jerk were assessed for all participants, with the overhead press assessed on two occasions to determine between-session reliability. The intraclass correlation coefficients (ICC) and 95% confidence intervals showed a high reliability for the overhead press ICC = 0.98 (0.97 – 0.99). A very strong correlation and significant differences were found between the overhead press and split jerk 1RM performances for all participants (r = 0.90 [0.93 – 0.85], 60.2 ± 18.3 kg, 95.7 ± 29.3 kg, p ≤ 0.001). Men demonstrated stronger correlations between the overhead press and split jerk 1RM performances (r = 0.83 [0.73-0.90], p ≤ 0.001) compared with women (r = 0.56 [0.17-0.80], p = 0.008). These results provide evidence that 1RM performance of the overhead press and split jerk performance are highly related, highlighting the importance of upper-limb strength in the split jerk maximum performance.

scholarly journals Organizational Factors as Predictors of Knowledge Management Practices in Federal University Libraries in Nigeria

2018 ◽  
Vol 13 (2) ◽  
pp. 48-69 ◽  
Author(s):  
Cyprian Ifeanyi Ugwu
Keyword(s):  
Knowledge Management ◽  
Management Practices ◽  
Correlation Coefficients ◽  
Organizational Factors ◽  
Management Tool ◽  
Management Support ◽  
University Libraries ◽  
Internal Reliability ◽  
Knowledge Management Practices ◽  
Positive Correlations

Abstract Objective – University libraries in Nigeria are facing challenges arising from poor funding, increasing user demands, and a competitive information environment. Knowledge management has been accepted by information professionals as a viable management tool, but issues surrounding its application require empirical investigation. The aim of this study is to determine the organizational factors that are correlates and predictors of knowledge management practices in federal university libraries in Nigeria. Methods – The study was based on a correlational research design. Twenty heads of university libraries in Nigeria responded to a structured questionnaire developed by the researcher. The questionnaire was validated by experts and its internal reliability was 0.78 obtained through Cronbach’s alpha procedures. The data collected were analyzed using Mean, Standard Deviation, One-Way ANOVA, Pearson’s Product Moment Correlation Coefficient, and regression analysis. Results – The study found that management support and collaboration were the most significant predictors of knowledge management practices in federal university libraries in Nigeria.  Even though human resources policy and rewards systems had positive correlations with knowledge management practices, their correlation coefficients were not significant. Conclusion – The success of knowledge management in university libraries in Nigeria depends on some contextual factors such as the support given by the management staff and the extent of collaboration among staff.

scholarly journals GEOMETRIC ASPECTS EVALUATION OF GNSS CONTROL NETWORK FOR DEFORMATION MONITORING IN THE JATIGEDE DAM REGION

2019 ◽  
Vol 15 (2) ◽  
pp. 167
Author(s):  
Made Ditha Ary Sanjaya ◽  
T. Aris Sunantyo ◽  
Nurrohmat Widjajanti
Keyword(s):  
Least Squares ◽  
Deformation Monitoring ◽  
Network Configuration ◽  
Control Networks ◽  
Quality Of Control ◽  
Least Squares Adjustment ◽  
Standard Deviations ◽  
Dam Deformation ◽  
Gnss Networks

Many factors led to dam construction failure so that deformation monitoring activities is needed in the area of the dam. Deformation monitoring is performed in order to detect a displacement at the control points of the dam. Jatigede Dam deformation monitoring system has been installed and started to operate, but there has been no evaluation of the geometry quality of control networks treated with IGS points for GNSS networks processing. Therefore, this study aims to evaluate the geometric quality of GNSS control networks on deformation monitoring of Jatigede Dam area. This research data includes the GNSS measurements of five CORS Jatigede Dam stations (R01, GG01, GCP04, GCP06, and GCP08) at doy 233 with network configuration scenarios of 12 IGS points on two quadrants (jat1), three quadrants (jat2), and four quadrants (jat3 and jat4). GNSS networks processing was done by GAMIT to obtain baseline vectors, followed by network processing usingparameter method of least squares adjustment. Networks processing with least squares adjustment aims to determine the most optimal  by precision and reliability criterion. Results of this study indicate that network configuration with 12 IGS stations in the two quadrants provides the most accurate coordinates of CORS dam stations. Standard deviations value of CORS station given by jat1 configuration are in the range of 2.7 up to 4.1 cm in X-Z components, whereas standard deviations in the Y component are in the range 5.8 up to 6.9 cm. An optimization assessment based on network strength, precision, and reliability factors shows optimum configuration by jat1.

scholarly journals Dampak Hubungan Karyawan dan Kedisiplinan Kerja terhadap Kinerja Karyawan

2019 ◽  
Vol 1 (2) ◽  
pp. 382-393
Author(s):  
Rizki Akbari ◽  
Kokom Komariah ◽  
Dicky Jhoansyah
Keyword(s):  
Employee Performance ◽  
Linear Regression Analysis ◽  
Correlation Coefficients ◽  
Multiple Linear Regression Analysis ◽  
Test Reliability ◽  
Coefficient Of Determination ◽  
Employee Relations ◽  
Analysis Technique ◽  
Multiple Correlation Coefficients ◽  
The Impact

The purpose of this study was to determine the impact of employee relations (variable X1) and Work Discipline (variable X2) on Employee Performance (variable Y). The method used in this research is to use descriptive and associative methods. Data collection techniques used by researchers in this study are through observation, questionnaire interviews, documentation and literature studies. The data analysis technique used is the validity test, reliability test, multiple linear regression analysis, including the test of the coefficient of determination and multiple correlation coefficients. The results of the test of the coefficient of determination seen from the value (Adjusted R2) of 0.531 can be interpreted that the impact of employee relations and working discipline on employee performance is equal to 53.1%. The remaining 46.9% is influenced by other factors outside this study. Conclusion, there is a moderate relationship between employee relations and work discipline with employee performance. Keywords: Employee Relations, Work Discipline, Employee Performance

scholarly journals Spectral Noise Levels and Roughness Severity Ratings for Normal and Simulated Rough Vowels Produced by Adult Males

1970 ◽  
Vol 13 (3) ◽  
pp. 489-502 ◽  
Author(s):  
Frank E. Sansone ◽  
Floyd W. Emanuel
Keyword(s):  
Correlation Coefficients ◽  
Adult Males ◽  
Noise Levels ◽  
Multiple Correlation ◽  
Acoustic Spectrum ◽  
Spectral Components ◽  
Multiple Correlation Coefficients ◽  
The Individual ◽  
Spectral Ranges ◽  
The Relationship

Twenty normal-speaking adult males sustained productions of each of the vowels /u/, /i/, /Λ/, /a/, and /æ/ first normally and then with simulated vocal roughness at one intensity. A tape recording of each production was rated for roughness on a five-point equal-appearing-intervals scale by 11 trained judges and was also analyzed to produce its 3-Hz bandwidth frequency-by-amplitude acoustic spectrum. The median roughness rating and the level of inharmonic spectral components, i.e., noise components, for each production were examined and related. Noise levels for the productions of each vowel averaged over selected spectral ranges between 100 Hz and 8000 Hz correlated highly with the median roughness ratings for those productions. Multiple correlation coefficients indicating the relationship between the median roughness rating and multiple measures of spectral noise in the range from 100 Hz to 2600 Hz for the individual productions of each test vowel were high (≥0.97) and significant for all five vowels.

scholarly journals Adaptive Least-Squares Collocation Algorithm Considering Distance Scale Factor for GPS Crustal Velocity Field Fitting and Estimation

2019 ◽  
Vol 11 (22) ◽  
pp. 2692 ◽  
Author(s):  
Wei Qu ◽  
Hailu Chen ◽  
Shichuan Liang ◽  
Qin Zhang ◽  
Lihua Zhao ◽  
...  
Keyword(s):  
Least Squares ◽  
Covariance Function ◽  
High Reliability ◽  
Scale Factor ◽  
Distance Scale ◽  
Crustal Movement ◽  
Least Squares Collocation ◽  
Crustal Velocity ◽  
Regional Tectonic ◽  
Gps Observations

High-precision, high-reliability, and high-density GPS crustal velocity are extremely important requirements for geodynamic analysis. The least-squares collocation algorithm (LSC) has unique advantages over crustal movement models to overcome observation errors in GPS data and the sparseness and poor geometric distribution in GPS observations. However, traditional LSC algorithms often encounter negative covariance statistics, and thus, calculating statistical Gaussian covariance function based on the selected distance interval leads to inaccurate estimation of the correlation between the random signals. An unreliable Gaussian statistical covariance function also leads to inconsistency in observation noise and signal variance. In this study, we present an improved LSC algorithm that takes into account the combination of distance scale factor and adaptive adjustment to overcome these problems. The rationality and practicability of the new algorithm was verified by using GPS observations. Results show that the new algorithm introduces the distance scale factor, which effectively weakens the influence of systematic errors by improving the function model. The new algorithm can better reflect the characteristics of GPS crustal movement, which can provide valuable basic data for use in the analysis of regional tectonic dynamics using GPS observations.

Measuring Exercise Self-Efficacy in Pregnant Women: Psychometric Properties of the Pregnancy-Exercise Self-Efficacy Scale (P-ESES)

2013 ◽  
Vol 21 (3) ◽  
pp. 349-359 ◽  
Author(s):  
Helen W. Bland ◽  
Bridget F. Melton ◽  
Elaine S. Marshall ◽  
Jacquelyn A. Nagle
Keyword(s):  
Pregnant Women ◽  
Psychometric Properties ◽  
Self Efficacy ◽  
Correlation Coefficients ◽  
Validity And Reliability ◽  
Multiple Correlation ◽  
Components Analysis ◽  
Multiple Correlation Coefficients ◽  
Original Measure ◽  
Activity Questionnaires

Background and Purpose: This study assessed the psychometric properties of a modified self-efficacy scale—the Pregnancy-Exercise Self-Efficacy Scale (P-ESES). Methods: Pregnant women completed the P-ESES and physical activity questionnaires (N = 88). Results: Internal consistency was confirmed by Cronbach’s alpha (α = 0.838) and equal-length Spearman–Brown (α = 8.22). Squared multiple correlation coefficients were calculated showing 9 of 10 items with values greater than the desired .5. A nonrotated exploratory principal components analysis confirmed the same 9 of 10 items loaded on a single factor, accounting for 46.1% of the variance. Each item had an acceptable load value of .40 or higher. Conclusions: Initial testing of the P-ESES confirmed validity and reliability with the exception of 1 item from the original measure: “Exercising without physician approval.”

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