scholarly journals Analysis of GEDI Elevation Data Accuracy for Inland Waterbodies Altimetry

2020 ◽  
Vol 12 (17) ◽  
pp. 2714
Author(s):  
Ibrahim Fayad ◽  
Nicolas Baghdadi ◽  
Jean Stéphane Bailly ◽  
Frédéric Frappart ◽  
Mehrez Zribi
Keyword(s):  
Standard Deviation ◽  
Space Station ◽  
Mean Difference ◽  
Water Levels ◽  
Ecosystem Dynamics ◽  
Systematic Bias ◽  
In Situ Data ◽  
Natural Lakes ◽  
The Mean

The Global Ecosystem Dynamics Investigation (GEDI) Light Detection And Ranging (LiDAR) altimetry mission was recently launched to the International Space Station with a capability of providing billions of high-quality measurements of vertical structures globally. This study assesses the accuracy of the GEDI LiDAR altimetry estimation of lake water levels. The difference between GEDI’s elevation estimates to in-situ hydrological gauge water levels was determined for eight natural lakes in Switzerland. The elevation accuracy of GEDI was assessed as a function of each lake, acquisition date, and the laser used for acquisition (beam). The GEDI elevation estimates exhibit an overall good agreement with in-situ water levels with a mean elevation bias of 0.61 cm and a standard deviation (std) of 22.3 cm and could be lowered to 8.5 cm when accounting for instrumental and environmental factors. Over the eight studied lakes, the bias between GEDI elevations and in-situ data ranged from −13.8 cm to +9.8 cm with a standard deviation of the mean difference ranging from 14.5 to 31.6 cm. Results also show that the acquisition date affects the precision of the GEDI elevation estimates. GEDI data acquired in the mornings or late at night had lower bias in comparison to acquisitions during daytime or over weekends. Even though GEDI is equipped with three identical laser units, a systematic bias was found based on the laser units used in the acquisitions. Considering the eight studied lakes, the beams with the highest elevation differences compared to in-situ data were beams 1 and 6 (standard deviations of −10.2 and +18.1 cm, respectively). In contrast, the beams with the smallest mean elevation difference to in-situ data were beams 5 and 7 (−1.7 and −2.5 cm, respectively). The remaining beams (2, 3, 4, and 8) showed a mean difference between −7.4 and +4.4 cm. The standard deviation of the mean difference, however, was similar across all beams and ranged from 17.2 and 22.9 cm. This study highlights the importance of GEDI data for estimating water levels in lakes with good accuracy and has potentials in advancing our understanding of the hydrological significance of lakes especially in data scarce regions of the world.

The Content of IMF Staff Reports for Euro Area Countries

2014 ◽  
pp. 272-292
Author(s):  
Lena Golubovskaja
Keyword(s):  
Standard Deviation ◽  
Euro Area ◽  
Mean Value ◽  
Systematic Bias ◽  
Executive Board ◽  
Sample Mean ◽  
Warning Tone ◽  
The Mean ◽  
Run Up ◽  
The Imf

This chapter analyzes the tone and information content of the two external policy reports of the Internal Monetary Fund (IMF), the IMF Article IV Staff Reports, and Executive Board Assessments for Euro area countries. In particular, the researchers create a tone measure denoted WARNING based on the existing DICTION 5.0 Hardship dictionary. This study finds that in the run-up to the current credit crises, average WARNING tone levels of Staff Reports for Slovenia, Luxembourg, Greece, and Malta are one standard deviation above the EMU sample mean; and for Spain and Belgium, they are one standard deviation below the mean value. Furthermore, on average for Staff Reports over the period 2005-2007, there are insignificant differences between the EMU sample mean and Staff Reports’ yearly averages. Researchers find the presence of a significantly increased level of WARNING tone in 2006 (compared to the previous year) for the IMF Article IV Staff Reports. There is also a systematic bias of WARNING scores for Executive Board Assessments versus WARNING scores for the Staff Reports.

scholarly journals Validity of self-reported weight: a study of urban brazilian adults

1993 ◽  
Vol 27 (4) ◽  
pp. 271-276 ◽  
Author(s):  
Maria I. Schmidt ◽  
Bruce B. Duncan ◽  
Mário Tavares ◽  
Carísi A. Polanczyk ◽  
Lúcia Pellanda ◽  
...  
Keyword(s):  
Body Mass Index ◽  
Standard Deviation ◽  
Body Mass ◽  
Mean Difference ◽  
Obesity Prevalence ◽  
Porto Alegre ◽  
Measured Weight ◽  
Prevalence Of Obesity ◽  
The Mean

In order to evaluate the validity of self-reported weight for use in obesity prevalence surveys, self-reported weight was compared to measured weight for 659 adults living in the Porto Alegre county, RS Brazil in 1986-87, both weights being obtained by a technician in the individual's home on the same visit. The mean difference between self-reported and measured weight was small (-0.06 +/- 3.16 kg; mean +/- standard deviation), and the correlation between reported and measured weight was high (r=0.97). Sixty-two percent of participants reported their weight with an error of < 2 kg, 87% with an error of < 4 kg, and 95% with an error of < 6 kg. Underweight individuals overestimated their weight, while obese individuals underestimated theirs (p<0.05). Men tended to overestimate their weight and women underestimate theirs, this difference between sexes being statistically significant (p=0.04). The overall prevalence of underweight (body mass index < 20) by reported weight was 11%, by measured weight 13%; the overall prevalence of obesity (body mass index > 30) by reported weight was 10%, by measured weight 11%. Thus, the validity of reported weight is acceptable for surveys of the prevalence of ponderosity in similar settings.

Validation of the AATSR Meteo Product Sea Surface Temperature

2006 ◽  
Vol 23 (5) ◽  
pp. 711-726 ◽  
Author(s):  
A. G. O'Carroll ◽  
J. G. Watts ◽  
L. A. Horrocks ◽  
R. W. Saunders ◽  
N. A. Rayner
Keyword(s):  
Standard Deviation ◽  
Surface Temperature ◽  
Sea Surface Temperature ◽  
European Space Agency ◽  
Tropical Rainfall Measuring Mission ◽  
Daily Basis ◽  
Mean Difference ◽  
Sea Surface ◽  
Lower Latitude

Abstract The Advanced Along Track Scanning Radiometer (AATSR) Sea Surface Temperature (SST) Meteo product, a fast-delivery level-2 product at 10 arc min spatial resolution, has been available from the European Space Agency (ESA) since 19 August 2002. Validation has been performed on these data at the Met Office on a daily basis, with a 2-day lag from data receipt. Meteo product skin SSTs have been compared with point measurements of buoy SST, a 1° climate SST analysis field compiled from in situ measurements and Advanced Very High Resolution Radiometer (AVHRR) SSTs, and a 5° latitude–longitude 5-day averaged in situ dataset. Comparisons of the AATSR Meteo product against Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) SSTs are also presented. These validation results have confirmed the AATSR Meteo product skin SST to be within ±0.3 K of in situ data. Comparisons of the AATSR skin SSTs against buoy SSTs, from 19 August 2002 to 20 August 2003, give a mean difference (AATSR – buoy) of 0.04 K (standard deviation = 0.28 K) during nighttime, and a mean difference of 0.02 K (standard deviation = 0.39 K) during the day. Analyses of the buoy matchups have shown that there is no cool skin effect observed in the nighttime observations, implying that the three-channel AATSR product skin SST may be 0.1–0.2 K too warm. Comparisons with TMI SSTs confirm that the lower-latitude SSTs are not significantly affected by residual cloud contamination.

Rapid Rhino versus Merocel nasal packs in septal surgery

2011 ◽  
Vol 125 (12) ◽  
pp. 1244-1246 ◽  
Author(s):  
A Hesham ◽  
A Ghali
Keyword(s):  
Standard Deviation ◽  
Pain Score ◽  
Visual Analogue Score ◽  
Nasal Packing ◽  
The Other ◽  
Septal Surgery ◽  
Patient Tolerance ◽  
Operative Complications ◽  
The Mean

AbstractObjective:To compare Rapid Rhino and Merocel packs for nasal packing after septoplasty, in terms of patient tolerance (both with the pack in place and during removal) and post-operative complications.Materials and methods:Thirty patients (aged 18–40 years) scheduled for septoplasty were included. Following surgery, one nasal cavity was packed with Rapid Rhino and the other one with Merocel. Patients were asked to record pain levels on a visual analogue score, on both sides, with the packs in situ and during their removal the next day. After pack removal, bleeding was compared on both sides.Results:The mean ± standard deviation pain score for the Rapid Rhino pack in situ (4.17 ± 1.78) was less than that for the Merocel pack (4.73 ± 2.05), but not significantly so (p = 0.314). The mean pain score for Rapid Rhino pack removal (4.13 ± 1.76) was significantly less that that for Merocel (6.90 ± 1.67; p = 0.001). Bleeding after pack removal was significantly less for the Rapid Rhino sides compared with the Merocel sides (p <0.05).Conclusion:Rapid Rhino nasal packs are less painful and cause less bleeding, compared with Merocel packs, with no side effects. Thus, their use for nasal packing after septal surgery is recommended.

scholarly journals Freeboard, snow depth and sea-ice roughness in East Antarctica from in situ and multiple satellite data

2011 ◽  
Vol 52 (57) ◽  
pp. 242-248 ◽  
Author(s):  
Thorsten Markus ◽  
Robert Massom ◽  
Anthony Worby ◽  
Victoria Lytle ◽  
Nathan Kurtz ◽  
...  
Keyword(s):  
Sea Ice ◽  
Correlation Coefficient ◽  
Satellite Data ◽  
Snow Depth ◽  
Large Scale ◽  
Mean Difference ◽  
Laser Altimeter ◽  
In Situ Data ◽  
Ice Roughness

AbstractIn October 2003 a campaign on board the Australian icebreaker Aurora Australis had the objective to validate standard Aqua Advanced Microwave Scanning Radiometer (AMSR-E) sea-ice products. Additionally, the satellite laser altimeter on the Ice, Cloud and land Elevation Satellite (ICESat) was in operation. To capture the large-scale information on the sea-ice conditions necessary for satellite validation, the measurement strategy was to obtain large-scale sea-ice statistics using extensive sea-ice measurements in a Lagrangian approach. A drifting buoy array, spanning initially 50 km × 100 km, was surveyed during the campaign. In situ measurements consisted of 12 transects, 50–500 m, with detailed snow and ice measurements as well as random snow depth sampling of floes within the buoy array using helicopters. In order to increase the amount of coincident in situ and satellite data an approach has been developed to extrapolate measurements in time and in space. Assuming no change in snow depth and freeboard occurred during the period of the campaign on the floes surveyed, we use buoy ice-drift information as well as daily estimates of thin-ice fraction and rough-ice vs smooth-ice fractions from AMSR-E and QuikSCAT, respectively, to estimate kilometer-scale snow depth and freeboard for other days. the results show that ICESat freeboard estimates have a mean difference of 1.8 cm when compared with the in situ data and a correlation coefficient of 0.6. Furthermore, incorporating ICESat roughness information into the AMSR-E snow depth algorithm significantly improves snow depth retrievals. Snow depth retrievals using a combination of AMSR-E and ICESat data agree with in situ data with a mean difference of 2.3 cm and a correlation coefficient of 0.84 with a negligible bias.

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.

Effect of Infrared Analyzer Homogenization Efficiency on Repeatability of Uncorrected Fat A and Fat B Signals

1994 ◽  
Vol 77 (5) ◽  
pp. 1217-1223 ◽  
Author(s):  
Erika B Smith ◽  
David M Barbano ◽  
Joanna M Lynch ◽  
J Richard Fleming
Keyword(s):  
Standard Deviation ◽  
Light Scattering ◽  
Raw Milk ◽  
Mean Difference ◽  
Sample Standard Deviation ◽  
The Mean ◽  
Infrared Analyzer

Abstract Poor repeatability by infrared milk analyzers may be caused by inefficient homogenization as a result of light scattering and the Christiansen effect. The objectives of this study were to identify instruments with good and poor homogenization efficiency and to determine if a difference exists in repeatability performance between instruments with good vs poor homogenization efficiency. Unhomo-genized and homogenized portions of the same milk were tested 20 times consecutively on 22 instruments. An instrument was considered to have poor homogenization efficiency if the mean difference in the uncorrected signal between unhomo-genized and homogenized portions of the same milk was ≥1.43% of the fat test (i.e., ≥0.05% at 3.5% fat). Instruments were evaluated for repeatability by calculating the sample standard deviation and the range of the latter 19 uncorrected readings for un-homogenized and homogenized milks. When repeatability was evaluated as a function of homogenization efficiency, there was a significant (p = 0.001) correlation between poor homogenization efficiency and poor repeatability when testing unho-mogenized milk but not when testing homogenized milk. Improved homogenizer performance within infrared milk analyzers is needed to improve the repeatability of raw milk testing.

Redefining the Neck: A Retrospective Review Utilizing Hyoid Suspension

2018 ◽  
Vol 35 (4) ◽  
pp. 198-204
Author(s):  
Sami A. Nizam ◽  
Rhys Branman
Keyword(s):  
Standard Deviation ◽  
Statistical Significance ◽  
Biomechanical Testing ◽  
Retrospective Chart Review ◽  
Mean Difference ◽  
Control Group ◽  
P Value ◽  
Hyoid Suspension ◽  
The Mean ◽  
Experimental Group

Neck contouring is one of the most frequent reasons patients seek cervicofacial rhytidectomy. But what makes for aesthetically pleasing youthful neck? Ellenbogen and Karlin described 5 criteria in their 1980 landmark publication, including having a cervicomental angle between 105° and 120° and a visible subhyoid depression. Recent advances in neck anatomy have revealed the existence of ligamentous like structures attaching the skin and platysma to the hyoid. These have been termed the hyoplatysmal ligament (HPL) and cervicomental suspensory angle ligament by different authors. This study was undertaken to determine whether surgically reestablishing the above structures utilizing a hyoid suspension technique resulted in statistically significant changes in cervicomental contour. A retrospective chart review was performed from January 2014 to present. After December 2016, the second author began utilizing a hyoid suspension technique where the inter- and subplatysmal fat was resected and the HPL was reestablished surgically (hyoid suspension). Cases before this date served as controls if a similar neck manipulation was performed without reestablishing the HPL. In total, 104 charts were queried, of which, 21 charts fit inclusion criteria to serve as controls and 20 as the experimental group. Before and after profile pictures were then compared for differences in cervicomental angle utilizing commercially available imaging software (Canfield Mirror, Parsippany, New Jersey). An unpaired Student t test was then performed to determine whether this 2 groups differed significantly utilizing a P value of .05 to denote statistical significance. The mean difference between pre- and postoperative cervicomental angle for the control group was 17.38° with a standard deviation of 8.05°. The mean difference between pre and postoperative cervicomental angle for the experimental group was 28.75° with a standard deviation of 15.52°. The resulting 11.37° difference in cervicomental angle between the 2 groups was found to be statistically significant with a P value of .0051. Our cosmetic surgical and anatomical knowledge continues to progress. Brant first described a ligamentous structure that attaches the platysma to the hyoid. Through biomechanical testing, he noted this ligament to be one of the weakest in the face and neck. Thereafter, in 2016 Yousif et al and Le Lourn separately described similar procedures to attach the platysma to the hyoid, in effect reestablishing this ligament. Utilizing one simple surgical maneuver, the hyoid suspension reestablishes the HPL. This surgically creates an acute cervicomental angle, resulting in less platysmal displacement postoperatively, with virtually no addition to surgical time or morbidity.

scholarly journals Biomass and production of Cladocera in Furnas Reservoir, Minas Gerais, Brazil

2010 ◽  
Vol 70 (3 suppl) ◽  
pp. 879-887 ◽  
Author(s):  
RM Santos ◽  
NF. Negreiros ◽  
LC. Silva ◽  
O. Rocha ◽  
MJ. Santos-Wisniewski
Keyword(s):  
Secondary Production ◽  
Aquatic Ecosystems ◽  
Total Production ◽  
In Situ Data ◽  
Production Values ◽  
Physical And Chemical Variables ◽  
Order Of Magnitude ◽  
The Mean ◽  
Physical And Chemical

Secondary production of zooplankton, the main energy pathway in many aquatic ecosystems, is crucial to an Understanding of functioning of these systems function. In this study, we analyzed the magnitude and seasonal variations of the population density, biomass and secondary production of Cladocera in the Furnas Reservoir (Brazil). Samples were carried out monthly at 6 points in the reservoir, from August 2006 to July 2007. Main physical and chemical variables in the water column were measured in situ. Data on density, biomass and development times were obtained and used to calculate the secondary production of eight Cladocera species. The total production of Cladocera varied from 0.02 to 28.6 mgDWm-3.day-1, among the sampling sites. The highest values were recorded in spring and summer months (September to January), and were correlated to the increase in the biomass of the phytoplankton. The mean production:biomass ratio was 0.32. The level of production in Furnas Reservoir fell within the range of those reported in the literature and was of the same order of magnitude of the production values recorded for oligotrophic reservoirs. Cladocera production differed spatially inside the Sapucaí compartment and also in the temporal scale, seasonally.

scholarly journals Amputee socks: Sock thickness changes with normal use

2015 ◽  
Vol 40 (3) ◽  
pp. 329-335 ◽  
Author(s):  
John C Cagle ◽  
Krittika J D’Silva ◽  
Brian J Hafner ◽  
Daniel S Harrison ◽  
Joan E Sanders
Keyword(s):  
Standard Deviation ◽  
Direct Measurement ◽  
Study Design ◽  
Clinical Relevance ◽  
Weight Bearing ◽  
Mean Difference ◽  
Initial Thickness ◽  
Reduced Volume ◽  
The Mean ◽  
Over Time

Background: Prosthetic socks are expected to decrease in thickness and have reduced volume accommodation with normal use. It is unknown, however, to what degree they reduce in thickness over time. Objective: The goal of this study was to determine a correlation between the age of a prosthetic sock (defined as the out-of-package time) and the resulting change in thickness under standardized weight-bearing and non-weight-bearing conditions. Study design: Experimental, mechanical assessment. Methods: Used prosthetic socks were donated by donors with transtibial amputation. Sock thickness was measured on a custom instrument under conditions representative of normal use. Stress-thickness response was compared to that of equivalent new socks to quantify the effects of use on sock performance. Results: Sock thickness changed non-linearly over time. On average, socks were 75% ± 17% of their initial thickness after 1 month, while socks older than 1 month were 72% ± 18% of their initial thickness. The elasticity of socks did not change with age. Conclusion: The volume accommodation provided by used socks cannot be reliably predicted by ply or age. Direct measurement of total sock thickness may provide meaningful insight to quantify prosthetic users’ socket fit and guide volume accommodation recommendations. Clinical relevance The mean difference in thickness between 3-ply and 5-ply used socks was equal to the standard deviation of each ply group (0.3mm). Therefore, it is possible that a 3-ply sock worn for as a little as 1 month could have a greater thickness than a 5-ply sock worn for a month.

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