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Orbit and clock products for quad-system satellites with undifferenced ambiguity fixing approach

Satellite Navigation 2024年第1期5卷 125-139页

作者： Jiaqi Wu Xingxing Li Yongqiang Yuan Keke Zhang Xin Li Jiaqing Lou Yun Xiong School of Geodesy and Geomatics Wuhan University129 Luoyu RoadWuhan430079China Hubei Luojia Laboratory 129 Luoyu RoadWuhan430079China German Research Centre for Geosciences GFZ Telegrafenberg14473PotsdamGermany Technische Universitat Berlin(TUB) Straße Des 17.Juni10623BerlinGermany

Integer Ambiguity Resolution(IAR)can significantly improve the accuracy of GNSS Precise Orbit Determination(POD).Traditionally,the IAR in POD is achieved at the Double Differenced(DD)*** this contribution,we develop an Un-Differenced(UD)IAR method for Global Positioning System(GPS)+BeiDou Navigation Satellite System(BDS)+Galileo navigation satellite system(Galileo)+Global'naya Navigatsionnaya Sputnikovaya Sistema(GLONASS)quad-system POD by calibrating UD ambiguities in the raw carrier phase and generating the so-called carrier *** on this method,we generate the UD ambiguity-fixed orbit and clock products for the Wuhan Innovation Application Center(IAC)of the International GNSS Monitoring and Assessment System(iGMAS).One-year observations in 2020 from 150 stations are employed to investigate performance of orbit and clock ***,the UD Ambiguity Resolution(AR)yields more resolved integer ambiguities than the traditional DD AR,scaling up to 9%,attributable to its avoidance of station baseline *** from the removal of ambiguity parameters,the computational efficiency of parameter estimation undergoes a substantial 70%*** with the float solution,the orbit consistencies of UD AR solution achieve the accuracy of 1.9,5.2,2.8,2.1,and 2.7 cm for GPS,BeiDou-2 Navigation Satellite System(BDS-2),BeiDou-3 Navigation Satellite System(BDS-3),Galileo,and GLONASS satellites respectively,reflecting enhancements of 40%,24%,54%,34%,and 42%.Moreover,the standard deviations of Satellite Laser Ranging(SLR)residuals are spanning 2.5–3.5 cm,underscoring a comparable accuracy to the DD AR solution,with discrepancies below 5%.A notable advantage of UD AR lies in its capability to produce the Integer Recovered Clock(IRC),facilitating Precise Point Positioning(PPP)AR without requiring additional Uncalibrated Phase Delay(UPD)*** assess the performance of quad-system kinematic PPP based on IRC,a network comprising 120 stations is uti

关键词： Multi-GNSS Precise orbit determination Integer recover clock Undifferenced ambiguity resolution iGMAS innovation application center

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Minimally Invasive Total Arterial Coronary Artery Bypass Grafting in Left Main Stem Disease

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World Journal of Cardiovascular Surgery 2024年第7期14卷 107-114页

作者： Pradeep Nambiar Radwan Husseini Prashant Sagar dr. Sulaiman Al Habib Hospital Dubai UAE Aster Hospital Dubai UAE

Objective: The aim was to show that Minimally Invasive total arterial revascularization for left main stem coronary artery disease, via a left anterior Mini thoracotomy using bilateral internal thoracic arteries is feasible, reproducible and safe. Further, there has been no exclusive data or experience with minimally invasive coronary artery bypass grafting in left main stem disease. Methods: From April 2019 to March 2024, 41 patients with left main stem stenosis, left main equivalent disease and unprotected left main with triple vessel disease underwent off pump minimally invasive multivessel coronary artery bypass grafting using either in situ pedicled Bilateral Internal Thoracic arteries or Left and Right Internal Thoracic artery Y composite conduits at three centers. Bilateral Internal Thoracic arteries were harvested under direct vision. All patients had an Intra-Aortic Balloon Pump inserted via the femoral artery prior to induction of anesthesia, to prevent any hemodynamic instability, arrhythmias, and was removed following completion of the procedure in the operating room without any complications. efficacy and outcomes were evaluated by i) Primary (MACCe)-Major Adverse Cardiac and Cardiovascular events and ii) Secondary outcome measures including total length of stay, return to full physical activity and quality of life. Mean follow-up was 1.4 years (Maximum was 2.5 years). Results: 41 patients with left main stem coronary artery stenosis, underwent total arterial revascularization using bilateral internal thoracic arteries. Left main stem stenosis was present in 29 patients, Unprotected left main stem stenosis with triple vessel disease in 7 and left main equivalence in 5 patients. In this cohort, 29 patients with only left main stem stenosis had 2 grafts each, 7 patients with left main and triple vessel disease had 3 grafts and 5 patients with left main equivalent disease had 2 grafts respectively. The average number of grafts was 2.2. One patient was conv

关键词： Left Main Stem Minimally Invasive CABG Bilateral Internal Mammary Arteries

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A Comparison of Four Neural Networks Algorithms on Locomotion Intention Recognition of Lower Limb exoskeleton Based on Multi-source Information

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Journal of Bionic engineering 2024年第1期21卷 224-235页

作者： Duojin Wang Xiaoping Gu Hongliu Yu Institute of Rehabilitation engineering and Technology University of Shanghai for Science and Technology516 Jungong RoadShanghai 200093China Shanghai engineering Research Center of Assistive Devices 516 Jungong RoadShanghai 200093China

Lower Limb exoskeletons(LLes)are receiving increasing attention for supporting activities of daily *** such active systems,an intelligent controller may be *** this paper,we proposed a locomotion intention recognition system based on time series data sets derived from human motion *** of input data and Deep Learning(DL)algorithms,this framework enables the detection and prediction of users’movement *** makes it possible to predict the detection of locomotion modes,allowing the LLes to provide smooth and seamless *** pre-processed eight subjects were used as input to classify four scenes:Standing/Walking on Level Ground(S/WOLG),Up the Stairs(US),Down the Stairs(DS),and Walking on Grass(WOG).The result showed that the ResNet performed optimally compared to four algorithms(CNN,CNN-LSTM,ResNet,and ResNet-Att)with an approximate evaluation indicator of 100%.It is expected that the proposed locomotion intention system will significantly improve the safety and the effectiveness of LLe due to its high accuracy and predictive performance.

关键词： Lower limb exoskeletons(LLes) Locomotion intention ResNet Multi-source

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enhancing Patient Safety in the Operating Room: A Comprehensive Guide from a Nurse’s Perspective

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Open Journal of Nursing 2024年第6期14卷 252-266页

作者： Aisha Mohamed Hussein Operating Room Nurse Dr. Sulaiman Al-Habib Medical Group Bone Joint and Spine Hospital Riyadh Saudi Arabia

ensuring patient safety within the operating room is a paramount concern in contemporary healthcare, and this guide aims to provide an in-depth exploration of this crucial aspect from the perspective of nurses. Nurses play a pivotal role in supporting surgeons and maintaining a safe environment for patients undergoing various medical procedures.

关键词： Operating Room Patient Safety Nurses

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Green Hydr.gen: Perspectives and Challenges in Using the Natural Gas Network in Ceará/Brazil

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Journal of Geoscience and environment Protection 2024年第3期12卷 70-94页

作者： Francisco Alfredo de Castro Mona Lisa Moura de Oliveira Lutero Carmo de Lima Daniel Silveira Serra Science and Technology Center State University of Ceará Ceará Brazil Av. dr. Silas Munguba 1700 Fortaleza-Ceará Brazil

Climate change, mainly caused by the use of non-renewable fuels, has raised global concerns and led to the search for less polluting energy sources, making hydr.gen a promising energy alternative with the potential to contribute to changes in the energy mix of various countries through the use of technologies that enable its production and use with low or zero carbon emissions. In this context, Brazil has aroused great interest from other countries in exploring its renewable resources for the production of hydr.gen (green hydr.gen). In this sense, the use of natural gas pipelines and the use of hydr.gen in mixtures with natural gas have become the subject of studies due to their economically viable alternative for the immediate use of this energy vector. However, there are still technical and regulatory challenges regarding the integration of hydr.gen into the existing natural gas pipeline network. In this context, the present study aims to addr.ss the effects of hydr.gen interaction with the structure of natural gas pipeline steel and the regulatory barriers to the use of this network for the transportation of green hydr.gen, particularly in the state of Ceará/Brazil. After extensive analysis of literature and regulatory documents, it was concluded that: 1) Ceará/Brazil has strong potential to meet the demand for green hydr.gen through the use of solar and wind energy sources;2) there is feasibility for the adaptation or conversion of natural gas infrastructure for the transportation of green hydr.gen;3) discussions regarding the regulatory competence of green hydr.gen transportation and distribution through the natural gas network in Brazil are still incipient;4) the current regulation of the natural gas industry can serve as a subsidy for the regulation of green hydr.gen and natural gas transportation.

关键词： Decarbonization Natural Gas Green Hydr.gen Pipelines

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Impacts of inter-satellite links on the eCOM model performance for BDS-3 MeO satellites

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Satellite Navigation 2024年第1期5卷 140-154页

作者： Chao Yang Jing Guo Xiaolong Xu Longyu Wang Qile Zhao GNSS Research Center Wuhan UniversityNo.129 Luoyu RoadWuhan430079China

Inter-satellite link(ISL)plays an essential role in current and future Global Navigation Satellite System(GNSS).In this study,we investigate the impact of ISL observations on precise orbit determination for BeiDou-3 Navigation Satellite System(BDS-3)Medium earth Orbit(MeO)satellites based on different extended CODe Orbit Models(eCOM).Thanks to the better observation geometry of the Ka-band ISL data compared to the L-band data for BDS-3 MeO satellites,the ISL solution substantially reduces Orbit Boundary Discontinuity(OBD)errors,except for C30,which suffers from unstable Ka-band hardware *** the external quality analysis,ISL significantly enhances the reliability of the orbit of MeO satellites manufactured by the China Academy of Space Technology(CAST).The standard deviation(STD)of the satellite laser ranging(SLR)residuals is approximately 2.5 cm,and the root mean square(RMS)is reduced by 10–23%compared to L-band ***,the Sun-elongation angle dependent systematic error in SLR residuals nearly vanishes based on the reduced 5-parameter eCOM(eCOM1)or extended 7-parameter eCOM(eCOM2)with ISL *** is because the ISL reduces the correlation between state parameters and solar radiation pressure(SRP)parameters as well as those among SRP parameters,leading to a more accurate estimation of both orbit and SRP perturbations,particularly those along B *** confirms that the deficiency of the SRP models for BDS-3 CAST satellites can be compensated by using better observation geometry from ISL *** the other hand,for the satellite manufactured by Shanghai engineering Center for Microsatellites(SeCM),the ISL allows for a more accurate estimation of the Bc_(1)parameter in the eCOM1 *** only reduces linear systematic error,possibly because the impact generated by the satellite bus cannot be entirely absorbed by the B-direction parameters.

关键词： BDS-3 MeO Inter-satellite link Solar radiation pressure eCOM

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Determination of global geodetic parameters using satellite laser ranging to Galileo,GLONASS,and BeiDou satellites

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Satellite Navigation 2024年第1期5卷 240-257页

作者： Xingxing Li Jiaqing Lou Yongqiang Yuan Jiaqi Wu Keke Zhang School of Geodesy and Geomatics Wuhan University129 Luoyu RoadWuhan430079HubeiChina

The new Global Navigation Satellite System(GNSS)satellites,including GLONASS,Galileo,and BeiDou system,are equipped with Laser Retroreflector Arrays(LRA)to support Satellite Laser Ranging(SLR)tracking,which contributes to the estimation of global geodetic *** this study,we estimate the global geodetic parameters using the SLR observations to GNSS satellites and also investigate the effects of different data processing strategies on the estimated earth Rotation Parameters(eRP),geocenter motion,and terrestrial *** results indicate that setting range bias parameters for each satellite-station pair can effectively account for the satellite-specific biases induced by LRAs,leading to smaller Root Mean Square errors(RMSe)of the post-fit SLR ***,estimating the range biases for each satellite-station pair improves the accuracy of the estimated station coordinates and *** also examine the impact of different arc lengths on the estimates of eRP,geocenter motion,and terrestrial *** results show that extending arc length can significantly reduce the formal error of *** 7-day strategy produces the smallest RMSes of 473 microarcseconds and 495 microarcseconds for the estimated X-and Y-component of pole coordinates,and 52 microseconds for length-of-day,***,the estimated geocenter motion is less affected by the arc length,even the shortest 1-day arc strategy can capture the seasonal variations of geocenter motion in Z *** scale estimation,extending the arc length notably improves the accuracy of the estimated station coordinates and scale,but this advantage becomes less noticeable in longer *** 7-day solution also obtains the closet scale results compared to ITRF2014,with the RMSe of 2.10×10^(–9).

关键词： Satellite laser ranging GNSS Geodetic parameters earth rotation parameters Geocenter motion Terrestrial scale

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Distribution of Cr,Cd,Cu,Pb and Zn in organs of three selected local fish species of Turag river,Bangladesh and impact assessment on human health

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emerging Contaminants 2023年第1期9卷 1-9页

作者： G.M.M.Anwarul Hasan Anuj Kumer Das Mohammed ASatter Md Asif Institute of Food Science and Technology(IFST) Bangladesh Council of Scientific and Industrial Research(BCSIR)Dr.Qudrat-E-Khuda RoadDhaka1205Bangladesh Hi-Tech Health Care Ltd. BananiDhaka1213Bangladesh

The current study estimates the contamination status of heavy metals in fish organs of three local fish species including Amblypharyngodon microlepis(Mola),Trichogaster chuna(Chuna Khalisha)and Annaldale Loach(Gutum fish)which were collected from Turag river during the months from January to March *** heavy metal concentrations of river water and fish organs were assessed through Atomic Absorption Spectrophotometer(AAS).Heavy metals in river water was detected in the order of Ni>Zn>Cu>Cd>Pb>Cr while metal accumulation in the fish organs were detected in the order of Zn>Cr>Cu>Pb>Cd,Zn>Cu>Cr>Pb>Cd and Zn>Cu>Cr>Pb>Cd for Trichogaster chuna,Amblypharyngodon microlepis and Annaldale Loach *** the detected heavy metals,highest contamination factor(CF)of Zn(1.104198)in intestine and lowest CF of Cu(0.00315)was detected in muscle of Amblypharyngodon microlepis(Mola).On the other hand,highest CF of Cd(1.072772)in liver and lowest CF of Zn(0.0225016)in gill of Trichogaster chuna(Chuna Khalisha)was *** case of Annaldale Loach(Gutum fish),highest CF of Cu(0.304122)in liver and lowest CF of Zn(0.002593)in intestine was *** total target hazard quotients(TTHQ)values of Amblypharyngodon microlepis in liver(1.18816)exceeded allowable threshold of 1 while TTHQ values in the muscle(1.8862)and liver(1.03995)of Annaldale Loach(Gutum fish)surpassed the acceptable standard limit as *** TTHQ values(Gill-0.18764,Muscle-2.1633,Intestine-1.68741,liver-1.03995,kidney-1.82188)for all of the organs of Trichogaster chuna(Chuna Khalisha)exceeded the acceptable standard limit which indicated possible non-cancer risk for all consumers and some of the fishes found unsafe if they are consumed for a longer ***,the target cancer risk(TCR)values indicated no potential cancer risks by consumption of those *** regulatory authorities should pay more attention to reduce the river water contamination through industrial effluents which might affect publ

关键词： Pollution The total target hazard quotients(TTHQ) Target cancer risk(TCR) Public health

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Land Use Land Cover Analysis for Godavari Basin in Maharashtra Using Geographical Information System and Remote Sensing

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Journal of Geographic Information System 2024年第1期16卷 21-31页

作者： Pallavi Saraf Dattatray G. Regulwar Department of Civil engineering Dr. Babasaheb Ambedkar Marathwada University Aurangabad India Department of Civil engineering Government College of Engineering Aurangabad India

The dynamic transformation of land use and land cover has emerged as a crucial aspect in the effective management of natural resources and the continual monitoring of environmental shifts. This study focused on the land use and land cover (LULC) changes within the catchment area of the Godavari River, assessing the repercussions of land and water resource exploitation. Utilizing LANDSAT satellite images from 2009, 2014, and 2019, this research employed supervised classification through the Quantum Geographic Information System (QGIS) software’s SCP plugin. Maximum likelihood classification algorithm was used for the assessment of supervised land use classification. Seven distinct LULC classes—forest, irrigated cropland, agricultural land (fallow), barren land, shrub land, water, and urban land—are delineated for classification purposes. The study revealed substantial changes in the Godavari basin’s land use patterns over the ten-year period from 2009 to 2019. Spatial and temporal dynamics of land use/cover changes (2009-2019) were quantified using three Satellite/Landsat images, a supervised classification algorithm and the post classification change detection technique in GIS. The total study area of the Godavari basin in Maharashtra encompasses 5138175.48 hectares. Notably, the built-up area increased from 0.14% in 2009 to 1.94% in 2019. The proportion of irrigated cropland, which was 62.32% in 2009, declined to 41.52% in 2019. Shrub land witnessed a noteworthy increase from 0.05% to 2.05% over the last decade. The key findings underscored significant declines in barren land, agricultural land, and irrigated cropland, juxtaposed with an expansion in forest land, shrub land, and urban land. The classification methodology achieved an overall accuracy of 80%, with a Kappa Statistic of 71.9% for the satellite images. The overall classification accuracy along with the Kappa value for 2009, 2014 and 2019 supervised land use land cover classification was good enough to d

关键词： GIS Remote Sensing Land Use Land Cover Change Change Detection Supervised Classification

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Basis for the diversity and extent in loss of digestible nutrients created by dietary phytin: emphasis on fowl and swine

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Animal Nutrition 2024年第1期16卷 422-428页

作者： edwin T.Moran Michael R.Bedford Poultry Science Department Auburn University AB Vista Woodstock Court Blenheim Road

Phytin is the Ca2+-Mg2+-K+salt of phytic acid that is created and deposited in the aleurone layer and/or germ of grains and legumes. Its high presence in feedstuffs for fowl and swine diets results in it being a universal and significant impediment to optimum performance. Phytin impairs gastrointestinal recovery of a wide array of nutrients, the effect varying with the nutrient concerned. On exposure to low pH during gastric digestion, phytin dissociates into phytic acid and solubilized Ca2+. even at low gastric pH,phytic acid is negatively charged which forms the basis of its anti-nutritive behavior. Pepsinogen has extensive basic amino acids on its activation peptide that are presented as cations at low pH which are targeted by pepsin for activation. Partially crystalized Ca2+near the enzyme?s active site further stabilizes its newly formed structure. Thus, phytic acid appears to interfere with gastric digestion by several mechanisms; interfering with pepsinogen activation by binding to the polypeptide?s basic amino acids;coordinating free Ca2+, destabilizing pepsin; binding some dietary proteins directly, further compromising gastric proteolysis. Upon digesta attaining neutrality in the duodenum, Ca2+and other cations rebind with accessible anions, phytic acid being a significant contender. Phytate not only binds free cations but can also strip them from enzymes(e.g. Ca2+, Zn2+) which reduces their structural resistance to autolysis and ability as co-factors(e.g. Zn2+) to increase enzyme activity. Goblet cells initially employ Ca2+as an electronic shield between mucin layers enabling granule formation and cell storage. After mucin granule release, Ca2+is progressively displaced by Na+to free the viscous mucins enabling its translocation. Mucin entangles with the glycocalyx of adjacent enterocytes thereby constructing the unstirred water layer（USWL）. excessive removal of Ca2+from mucin by phytic acid increases its fluidity facilitating its loss from the USWL with

关键词： Digestive enzyme Calcium endogenous protein Mucin Phytin

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