scholarly journals Quality of Orbit Predictions for Satellites Tracked by SLR Stations

2021 ◽  
Vol 13 (7) ◽  
pp. 1377
Author(s):  
Joanna Najder ◽  
Krzysztof Sośnica
Keyword(s):  
Extreme Case ◽  
Laser Ranging ◽  
Artificial Satellites ◽  
Satellite Orbits ◽  
Satellite Systems ◽  
Quality Degradation ◽  
The Earth ◽  
The Mean ◽  
Over Time

This study aims to evaluate and analyze the orbit predictions of selected satellites: geodetic, Global Navigational Satellite Systems (GNSS), and scientific low-orbiting, which are tracked by laser stations. The possibility of conducting satellite laser ranging (SLR) to artificial satellites depends on the access to high-quality predictions of satellite orbits. The predictions provide information to laser stations where to aim the telescope in search of a satellite to get the returns from the retroreflectors installed onboard. If the orbit predictions are very imprecise, SLR stations must spend more time to correct the telescope pointing, and thus the number of collected observations is small or, in an extreme case, there are none of them at all. Currently, there are about 120 satellites equipped with laser retroreflectors orbiting the Earth. Therefore, the necessity to determine the quality of predictions provided by various analysis centers is important in the context of the increasing number of satellites tracked by SLR stations. We compare the orbit predictions to final GNSS orbits, precise orbits of geodetic satellites based on SLR measurements determined in postprocessing, and kinematic orbits of low-orbiting satellites based on GPS data. We assess the quality degradation of the orbit predictions over time depending on the type of orbit and the satellite being analyzed. We estimate the time of usefulness of prediction files, and indicate those centers which publish most accurate predictions of the satellites’ trajectories. The best-quality predictions for geodetic satellites and Galileo reach the mean error of 0.5–1 m for the whole 5-day prediction file (for all three components), while the worst ones can reach values of up to several thousand meters during the first day of the prediction.

scholarly journals Evolution of orbit and clock quality for real-time multi-GNSS solutions

GPS Solutions ◽  
2020 ◽  
Vol 24 (4) ◽  
Author(s):  
Kamil Kazmierski ◽  
Radoslaw Zajdel ◽  
Krzysztof Sośnica
Keyword(s):  
Real Time ◽  
Atomic Clock ◽  
Orbital Plane ◽  
Poor Quality ◽  
Satellite Orbits ◽  
High Quality ◽  
Changes Over Time ◽  
Over Time ◽  
Orbit Characteristics

Abstract High-quality satellite orbits and clocks are necessary for multi-GNSS precise point positioning and timing. In undifferenced GNSS solutions, the quality of orbit and clock products significantly influences the resulting position accuracy; therefore, for precise positioning in real time, the corrections for orbits and clocks are generated and distributed to users. In this research, we assess the quality and the availability of real-time CNES orbits and clocks for GPS, GLONASS, Galileo, and BeiDou-2 separated by satellite blocks and types, as well as the product quality changes over time. We calculate the signal-in-space ranging error (SISRE) as the main orbit and clock quality indicator. Moreover, we employ independent orbit validation based on satellite laser ranging. We found that the most accurate orbits are currently available for GPS. However, Galileo utmost stable atomic clocks compensate for systematic errors in Galileo orbits. As a result, the SISRE for Galileo is lower than that for GPS, equaling 1.6 and 2.3 cm for Galileo and GPS, respectively. The GLONASS satellites, despite the high quality of their orbits, are characterized by poor quality of clocks, and together with BeiDou-2 in medium and geosynchronous inclined orbits, are characterized by SISRE of 4–6 cm. BeiDou-2 in geostationary orbits is characterized by large orbital errors and the lowest availability of real-time orbit and clock corrections due to a large number of satellite maneuvers. The quality of GNSS orbit and clock corrections changes over time and depends on satellite type, block, orbit characteristics, onboard atomic clock, and the sun elevation above the orbital plane.

Quality of Split-Mouth Trials in Dentistry: 1998, 2008, and 2018

2020 ◽  
Vol 99 (13) ◽  
pp. 1453-1460
Author(s):  
D. Qin ◽  
F. Hua ◽  
H. He ◽  
S. Liang ◽  
H. Worthington ◽  
...  
Keyword(s):  
Sample Size ◽  
Methodological Quality ◽  
Linear Models ◽  
Sample Size Calculation ◽  
Reporting Quality ◽  
Treatment Groups ◽  
Item Checklist ◽  
The Mean ◽  
Over Time

The objectives of this study were to assess the reporting quality and methodological quality of split-mouth trials (SMTs) published during the past 2 decades and to determine whether there has been an improvement in their quality over time. We searched the MEDLINE database via PubMed to identify SMTs published in 1998, 2008, and 2018. For each included SMT, we used the CONsolidated Standards Of Reporting Trials (CONSORT) 2010 guideline, CONSORT for within-person trial (WPT) extension, and a new 3-item checklist to assess its trial reporting quality (TRQ), WPT-specific reporting quality (WRQ), and SMT-specific methodological quality (SMQ), respectively. Multivariable generalized linear models were performed to analyze the quality of SMTs over time, adjusting for potential confounding factors. A total of 119 SMTs were included. The mean overall score for the TRQ (score range, 0 to 32), WRQ (0 to 15), and SMQ (0 to 3) was 15.77 (SD 4.51), 6.06 (2.06), and 1.12 (0.70), respectively. The primary outcome was clearly defined in only 28 SMTs (23.5%), and only 27 (22.7%) presented a replicable sample size calculation. Only 45 SMTs (37.8%) provided the rationale for using a split-mouth design. The correlation between body sites was reported in only 5 studies (4.2%) for sample size calculation and 4 studies (3.4%) for statistical results. Only 2 studies (1.7%) performed an appropriate sample size calculation, and 46 (38.7%) chose appropriate statistical methods, both accounting for the correlation among treatment groups and the clustering/multiplicity of measurements within an individual. Results of regression analyses suggested that the TRQ of SMTs improved significantly with time ( P < 0.001), while there was no evidence of improvement in WRQ or SMQ. Both the reporting quality and methodological quality of SMTs still have much room for improvement. Concerted efforts are needed to improve the execution and reporting of SMTs.

scholarly journals Impact on Health-Related Quality of Life and Costs of Managing Chronic Neuropathic Pain in Academic Pain Centres: Results from a One-Year Prospective Observational Canadian Study

2015 ◽  
Vol 20 (6) ◽  
pp. 327-333 ◽  
Author(s):  
J-E Tarride ◽  
DE Moulin ◽  
M Lynch ◽  
AJ Clark ◽  
L. Stitt ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Economic Value ◽  
Health Related Quality ◽  
Policy Makers ◽  
Related Quality ◽  
Health Related ◽  
The Mean ◽  
One Year ◽  
Over Time

BACKGROUND: The management of chronic pain, including neuropathic pain (NeP), is a major public health issue. However, there is a paucity of data evaluating pain management strategies in real-life settings.OBJECTIVE: To inform policy makers about the economic value of managing chronic NeP in academic centres by conducting a subeconomic assessment of a Canadian multicentre cohort study aimed at determining the long-term outcomes of the management of chronic NeP in academic pain centres. Specific questions regarding the economic value of this type of program were answered by a subset of patients to provide further information to policy makers.METHODS: Baseline demographic information and several pain-related measurements were collected at baseline, three, six and 12 months in the main study. A resource use questionnaire aimed at determining NeP-related costs and the EuroQoL-5 Dimension were collected in the subset study from consenting patients. Statistical analyses were conducted to compare outcomes over time and according to responder status.RESULTS: A total of 298 patients were evaluated in the present economic evaluation. The mean (± SD) age of the participants was 53.7±14.0 years, and 56% were female. At intake, the mean duration of NeP was >5 years. Statistically significant improvements in all pain and health-related quality of life outcomes were observed between the baseline and one-year visits. Use decreased over time for many health care resources (eg, visits to the emergency room decreased by one-half), which resulted in overall cost savings.CONCLUSION: The results suggest that increased access to academic pain centres should be facilitated in Canada.

scholarly journals Integrated Quality-Based Production-Distribution Planning in Two-Echelon Supply Chains

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Husein Pasha ◽  
Isa Nakhai Kamalabadi ◽  
Alireza Eydi
Keyword(s):  
Mixed Integer ◽  
High Quality ◽  
Swarm Optimization ◽  
Integrated Production ◽  
Quality Degradation ◽  
Production Distribution ◽  
Quality Of Products ◽  
Over Time

The integrated production-distribution (P-D) planning has turned into one of the most essential areas in supply chain (SC) management in recent years, especially in the case of perishable products in which the quality of products can change over time. Nonetheless, so far, the suggested models have focused on the P-D stages of the chain while the delivery of high-quality products to customers is of paramount significance in the perishable SC. In the present paper, a multiobjective, mixed-integer, and nonlinear programming (MOMINLP) mathematical model was developed for integrated P-D deteriorating items in a two-echelon SC that emphasizes quality degradation. Quality is monitored and calculated as a function of temperature and time throughout the SC, and the main purpose of the model is to first increase the quality of products delivered to customers and, second, minimize the SC costs. To optimize the problem, the particle swarm optimization (PSO) approach was also incorporated into the model. The obtained model was applied to a case study in Protein Gostar Sina Company in Iran, which resulted in decreased P-D costs as well as increased customer satisfaction.

scholarly journals Quality of bovine colostrum and its relation to genetics, management, physiology and its freezing

2020 ◽  
pp. e1465
Author(s):  
Ana Luiza Schogor ◽  
Patricia Glombowsky ◽  
Fabiana Both ◽  
Beatriz Danieli ◽  
Fernanda Rigon ◽  
...  
Keyword(s):  
Holstein Cows ◽  
Total Serum Protein ◽  
Total Serum ◽  
Freezing Process ◽  
Plasma Protein Concentration ◽  
Protein Levels ◽  
The Mean ◽  
Over Time ◽  
Process Material

Objective. The aims of this study were to assess whether colostrum quality is modified by genetic, physiological and management characteristics in the pre-partum period, as well as evaluate whether quality and composition of colostrum is altered in the freezing process. Material and methods. In the experiment I, colostrum and blood samples of 35 cows (18 Holstein and 17 Jerseys) were collected. In the experiment II, six colostrum samples of Holstein cows were collected and frozen during 60 days. Results. The mean immunoglobulin (Ig) concentration was 77.65 mg/ml to Jersey and 82.77 mg/ml to Holstein. The genetic, parturition order, and the interaction between these factors were no significant on IgG concentration in the colostrum. Also, it was observed an effect genetic of cow in the weight on calf at birth and on three days of age (p<0.0001). Regarding transmission of calf passive immunity, no effects of cow breed and calving order were observed on plasma protein concentration of calf, as well as after three days of freezing. Calves of Holstein (83%) and Jersey (82%) breed showed total serum protein levels above 5.5 g/dL. Holstein cows housed in individual paddocks with diet supplementation provided better quality of colostrum (93.57 mg Ig/mL). Over time, the percentage of fat reduced at freezing, that reduced over time (p<0.05) in Experiment II. Conclusions. The pre-partum management exerts influence on colostrum quality, and the freezing not interfere on centesimal and immunological quality of colostrum, with exception the fat, that decrease along the time.

Impacts of solar events on atmospheric density variations as revealed by Satellite Laser Ranging orbits.

2020 ◽  
Author(s):  
Florent Deleflie ◽  
Changyong Hé ◽  
Carine Briand ◽  
Muhammad Ali Sammuneh ◽  
Pieter Visser
Keyword(s):  
Laser Ranging ◽  
Artificial Satellites ◽  
Satellite Orbits ◽  
High Latitudes ◽  
Atmospheric Drag ◽  
Crucial Importance ◽  
Atmospheric Density ◽  
Comprehensive Comparison ◽  
Solar Events ◽  
Grace Mission

&lt;p&gt;This paper is focused on precise orbitography with SLR data, using as well when they are available accelerometric data, as in the GRACE mission. The main purpose of this paper is to analyse whether low SLR satellite orbits (namely Starlette, Stella, Lares, Ajisai) are sensitive or not to variations of the atmospheric density due to solar events over the period 2003-2019, and including the ones that occurred in 2017.&lt;/p&gt;&lt;p&gt;The relationships between solar events and the way they modify the density of the Earth's thermosphere, as revealed by perturbations induced on artificial satellites orbits, are in fact of crucial importance for satellite operators. A wide literature focused on these issues already exists, but it appears to the authors that some improvements of thermosphere models are still expected, especially at high latitudes. This paper aims, hence, at contributing to fill a gap in that direction. &amp;#160;&lt;/p&gt;&lt;p&gt;We first select over the period 1984-2019 a list of solar events that may be representative of the conditions that may heat the terrestrial atmosphere, in terms of geometrical configurations and the intensity of solar activity. The goal is to identify whether these events have impacted or not the thermospheric density at some relevant altitudes; therefore, a post-fit residual analysis is provided, accounting for the whole set of tracking data acquired by the stations of the ILRS network. A comprehensive comparison between precise results obtained with SLR and accelerometric data, using different atmospheric drag modelling, is then provided.&lt;/p&gt;

Chronic pain in multiple sclerosis: A10-year longitudinal study

2017 ◽  
Vol 16 (1) ◽  
pp. 198-203 ◽  
Author(s):  
Jamie Young ◽  
Bhasker Amatya ◽  
Mary P. Galea ◽  
Fary Khan
Keyword(s):  
Quality Of Life ◽  
Multiple Sclerosis ◽  
Chronic Pain ◽  
Longitudinal Study ◽  
The Mean ◽  
The Impact ◽  
Over Time

AbstractBackground and purposePain is a common symptom associated with multiple sclerosis (MS), and has lasting effects on an individual’s functional capacity and quality of life. A wide range of prevalence rates of pain (between 23% and 90%)have been reported in MS and this is mainly due to the methodological differences amongst the studies such as variability in patient sources, method of sampling and the definition of pain used. Chronic pain in MS, defined as pain lasting for greater than 3–6 months, can have a significant impact on their biopsychosocial health, including negative impact on activities of daily living, relationships and social participation. The long-term course of MS-related pain and its impact in an Australian cohort over a 7-year period has been investigated earlier. The aim of this longitudinal study was to describe the impact of chronic pain, pain-related disability and carer burden in persons with MS over a 10-year period. The aim of this longitudinal study was to describe the impact of chronic pain, pain-related disability and carer burden in persons with MS over a 10-year period.MethodsThis was a prospective longitudinal study conducted at the Rehabilitation Department of Royal Melbourne Hospital (RMH), a tertiary referral hospital in Victoria and Australia. The source of participants was from the RMH MS database and contains detailed MS patient information including demographic data, diagnosis details (using McDonald’s criteria), pain characteristics. Structured face-face interviews and validated measures were used, which include the visual analogue scale (VAS); chronic pain grade (CPG); the assessment of quality of life (AQoL) and the carer strain index (CSI). The mean age of the participants (n = 70) was 55.3 years and majority (70%) were female.ResultsThe mean age of the participants (n = 70) was 55.3 years and majority (70%) were female. The findings show that over time (10 years), participants report having greater bilateral bodily pain and greater description of pain as ‘worse as it could be’. Pain types were similar to 7-years follow-up but remained higher than baseline. There was a significant deterioration in quality of life in those with more severe CPG over time. Almost half of the participants 31 (44%) required care either from a private carer, institution or from a family member. Although fear of taking medications and side effects were common barriers to treatment for pain, there was an increase in the use of pharmacological treatment over time and an increase in the use of healthcare services, mainly neurologists and general practitioners.ConclusionsThe pain measures reported by the participants were similar to those at the 7-year follow-up except there was a greater representation of bilateral pain locations (limb, trunk and facial pain) compared to baseline and 7-year follow-up. At 10-year follow-up, more participants used medications compared tc 7-year follow-up and there was an increase in the use of health professionals at the 10-year follow-up At the 10-year follow up QoL of the participants deteriorated significantly and more participants had progressed to higher CPGIII and CPGIV. This study demonstrates that chronic pain is a significant issue over time in MS, with clinical and health implications, impact on quality of life, disability and healthcare utilization.ImplicationsGreater awareness of chronic pain in pwMS, cognitive classifications and an interdisciplinary approach is required to improve long-term patient outcomes and well-being.Crown Copyright © 2017 Published by Elsevier B.V. on behalf of Scandinavian Association for the Study of Pain. All rights reserved.

Measuring the Improving Quality of Outpatient Care in Medical Oncology Practices in the United States

2013 ◽  
Vol 31 (11) ◽  
pp. 1471-1477 ◽  
Author(s):  
Michael N. Neuss ◽  
Jennifer L. Malin ◽  
Stephanie Chan ◽  
Pamela J. Kadlubek ◽  
John L. Adams ◽  
...  
Keyword(s):  
Clinical Information ◽  
The United States ◽  
Measuring Process ◽  
The Past ◽  
The Mean ◽  
Highly Correlated ◽  
American Society ◽  
Oncology Practice ◽  
Over Time

Purpose The American Society of Clinical Oncology Quality Oncology Practice Initiative (QOPI) has provided a method for measuring process-based practice quality since 2006. We sought to determine whether QOPI scores showed improvement in measured quality over time and, if change was demonstrated, which factors in either the measures or participants were associated with improvement. Methods The analysis included 156 practice groups from a larger group of 308 that submitted data from 2006 to 2010. One hundred fifty-two otherwise eligible practices were excluded, most commonly for insufficient data submission. A linear regression model that controlled for varied initial performance was used to estimate the effect of participation over time and evaluate participant and measure characteristics of improvement. Results Participants completed a mean of 5.06 (standard deviation, 1.94) rounds of data collection. Adjusted mean quality scores improved from 0.71 (95% CI, 0.42 to 0.91) to 0.85 (95% CI, 0.60 to 0.95). Overall odds ratio of improvement over time was 1.09 (P < .001). The greatest improvement was seen in measures that assessed newly introduced clinical information, in which the mean scores improved from 0.05 (95% CI, 0.01 to 0.17) to 0.69 (95% CI, 0.33 to 0.91; P < .001). Many measures showed no change over time. Conclusion Many US oncologists have participated in QOPI over the past 6 years. Participation over time was highly correlated with improvement in measured performance. Greater and faster improvement was seen in measures concerning newly introduced clinical information. Some measures showed no change despite opportunity for improvement.

The Impact of STRICTA and CONSORT on Reporting of Randomised Control Trials of Acupuncture: A Systematic Methodological Evaluation

2018 ◽  
Vol 36 (6) ◽  
pp. 349-357 ◽  
Author(s):  
Simen Svenkerud ◽  
Hugh MacPherson
Keyword(s):  
Positive Impact ◽  
Meta Analysis ◽  
Reporting Quality ◽  
Primary Analysis ◽  
Quality Of Reporting ◽  
The Mean ◽  
Time Periods ◽  
The Impact ◽  
Over Time

Background Clear and unambiguous reporting is essential for researchers and clinicians to be able to assess the quality of research. To enhance the quality of reporting, consensus-based reporting guidelines are commonly used. Objectives To update and extend previous research by evaluating the more recent impact of STRICTA (STandards for Reporting Interventions in Controlled Trials of Acupuncture) and CONSORT (CONsolidated Standards Of Reporting Trials) guidelines on the quality of reporting of acupuncture trials. Methods By random sampling, approximately 45 trials from each of five 2-year time periods between 1994 and 2015 were included in the study. Using scoring sheets based on the STRICTA and CONSORT checklist items (range 0 to 7 and 0 to 5, respectively), the distribution of items reported over time was investigated, with changes shown using scatterplots. The primary analysis used a before-and-after t-test to compare time periods. A meta-analysis investigated whether or not trials published in journals that endorsed STRICTA were associated with better reporting. Results The study included 207 trials. Improved reporting of items over time was observed, as represented by changes in the scatterplot slope and intercept. The mean STRICTA score increased from 4.27 in the 1994–1995 period to 5.53 in 2014–2015, an 18% improvement. The mean CONSORT score rose from 1.01 in the 1994–1995 period to 3.32 in 2014–2015, an increment of 46%. There was proportionately lower reporting for items related to practitioner background (STRICTA) and for randomisation implementation and allocation concealment (CONSORT). Trials published in journals that endorsed STRICTA had statistically significantly superior reporting of both STRICTA and CONSORT items overall. Conclusion This study has provided evidence of an improvement in reporting of STRICTA and CONSORT items over the time period from 1994 to 2015. Journals that endorse STRICTA have a better record in terms of reporting quality. Some evidence suggests that the publication of STRICTA has had a positive impact on reporting quality.

scholarly journals Mean Orbital Motion of Geodetic Satellites and its Applications

1997 ◽  
Vol 165 ◽  
pp. 332-340
Author(s):  
P. Exertier ◽  
G. Métris ◽  
S. Bruinsma ◽  
F. Barlier
Keyword(s):  
Orbital Motion ◽  
Temporal Variations ◽  
Artificial Satellites ◽  
Tracking Data ◽  
Mission Analysis ◽  
Averaging Methods ◽  
Earth Gravity Field ◽  
Earth Gravity ◽  
The Earth ◽  
The Mean

AbstractAveraging methods are convenient tools for studying long-periodic variations of the motion of artificial satellites. The main lines of a semi-analytical theory of the mean motion are given. We show how, when coupled with a careful reduction of the tracking data, this theory allows to determine parameters related to the temporal variations of the Earth gravity field (e.g. the amplitude of 18.6 years tide and the secular variation of even zonal harmonics). The theory is also very useful for other applications such as mission analysis.

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