scholarly journals Sampling error of continuous periodic data and its application for geodesy

Author(s):  
Lorant Földváry
Keyword(s):  
Author(s):  
Lorant Foldvary

Data acquisition for geoinformatics cannot be done continuously, but by discrete sampling of the object or phenomenon. The sampling involves errors on the knowledge of the continuous signal due to the loss of information in the sampling procedure. In the present study, an analytical formulation of the sampling error is provided, which embodies the amplitude, phase, bias and periodicity of the sampling error. The analysis is then subsequently applied for case studies: for the GRACE and GRACE-FO monthly solutions, and for different realizations of the Hungarian Gravimetric Network.


2008 ◽  
Author(s):  
Robin Hau ◽  
Timothy J. Pleskac ◽  
Ralph Hertwig
Keyword(s):  

Crop Science ◽  
1986 ◽  
Vol 26 (2) ◽  
pp. 380-383 ◽  
Author(s):  
R. C. Johnson ◽  
H. T. Nguyen ◽  
R. W. McNew ◽  
D. M. Ferris

2021 ◽  
Vol 11 (01) ◽  
pp. e55-e59
Author(s):  
Farzaneh Motamed ◽  
Ghobad Heidari ◽  
Bita Heirati ◽  
Parisa Rahmani

AbstractLiver biopsy is the gold standard for the diagnosis and management of various liver diseases; however, noninvasive diagnostic modalities may help prevent adverse effects of anesthesia, prolonged hospitalization, sampling error, and other serious complications, particularly in pediatric patients. The aim of this study is to compare the results of liver biopsy and fibroscan in children with chronic liver diseases. All patients presenting chronic liver disease admitted in the ward or clinic of Tehran's Children Medical Center were enrolled in the study. Required laboratory tests were performed to diagnose the disease, followed by elastography using fibroscan 402 (M-probe) Echosens machine and liver biopsy using Menghini technique. Samples were scored by using METAVIR scoring system. Thirty-two patients were reported (68.8%, female) with autoimmune hepatitis (18.8%), Wilson disease (12.5%), and glycogen storage disease (12.5%). The most common pathologic stage and fibroscan result was stage III and F0 (46.9%), respectively. Association between pathology and fibroscan results was not significant. Nonetheless, age and diagnosis, age and Fibroscan score, and pathology and liver function test were significantly associated with each other. Fibroscan cannot be used as an alternative to liver biopsy; however, it can be a useful accessory tool.


2004 ◽  
Vol 36 (6) ◽  
pp. 735-740 ◽  
Author(s):  
HELLE PULLMANN ◽  
JÜRI ALLIK ◽  
RICHARD LYNN

The Standard Progressive Matrices test was standardized in Estonia on a representative sample of 4874 schoolchildren aged from 7 to 19 years. When the IQ of Estonian children was expressed in relation to British and Icelandic norms, both demonstrated a similar sigmoid relationship. The youngest Estonian group scored higher than the British and Icelandic norms: after first grade, the score fell below 100 and remained lower until age 12, and after that age it increased above the mean level of these two comparison countries. The difference between the junior school children and the secondary school children may be due to schooling, sampling error or different trajectories of intellectual maturation in different populations. Systematic differences in the growth pattern suggest that the development of intellectual capacities proceeds at different rates and the maturation process can take longer in some populations than in others.


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