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Evaluation of E-sail parameters on central spacecraft attitude stability using a high-fidelity rigid–flexible coupling model

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Astrodynamics 2024年第2期8卷 271-284页

作者： Chonggang Du Zheng h.Zhu Changqing Wang Aijun Li Tuanjie Li School of Electro-Mechanical Engineering Xidian UniversityXi’an 710071China Department of Mechanical Engineering York University4700 Keele StreetTorontoOntario M3J 1P3Canada School of Automation Northwestern Polytechnical UniversityXi’an 710129China

This study examines the impact of electric solar wind sail(E-sail)parameters on the attitude stability of E-sail’s central spacecraft by using a comprehensive rigid–flexible coupling dynamic *** this model,the nodal position finite element method is used to model the elastic deformation of the tethers through interconnected two-node tensile *** attitude dynamics of the central spacecraft is described using a natural coordinate *** rigid–flexible coupling between the central spacecraft and its flexible tethers is established using Lagrange *** research reveals the significant influences of parameters such as tether numbers,tether’s electric potential,and solar wind velocity on attitude ***,solar wind fluctuations and the distribution of electric potential on the main tethers considerably affect the attitude stability of the *** consistent management,the angular velocities of the spacecraft must remain at target ***,the attitude stability of a spacecraft has a pronounced dependence on the geometrical configuration of the E-sail,with axisymmetric E-sails proving to be more stable.

关键词： electric solar wind sail(E-sail) space tether nodal position finite element method(NPFEM) natural coordinate formulation (NCF) attitude stability

Improving the Transmission Security of Vein Images Using a Bezier Curve and Long Short-Term Memory

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Computers, Materials & Continua 2024年第6期79卷 4825-4844页

作者： Ahmed h.Alhadethi Ikram Smaoui Ahmed Fakhfakh Saad M.Darwish Computer Science and School of Electronics and Telecommunications University of SfaxSfax3029Tunisia LETI Laboratory University of SfaxSfax3029Tunisia Digital Research Center of Sfax Technopark of SfaxSfax3029Tunisia Department of Information Technology Institute of Graduate Studies and ResearchAlexandria UniversityAlexandriaEgypt

The act of transmitting photos via the Internet has become a routine and significant *** the security measures to safeguard these images from counterfeiting and modifications is a critical domain that can still be further *** study presents a system that employs a range of approaches and algorithms to ensure the security of transmitted venous *** main goal of this work is to create a very effective system for compressing individual biometrics in order to improve the overall accuracy and security of digital photographs by means of image *** paper introduces a content-based image authentication mechanism that is suitable for usage across an untrusted network and resistant to data loss during *** employing scale attributes and a key-dependent parametric Long Short-Term Memory(LSTM),it is feasible to improve the resilience of digital signatures against image deterioration and strengthen their security against malicious ***,the successful implementation of transmitting biometric data in a compressed format over a wireless network has been *** applications involving the transmission and sharing of images across a *** suggested technique utilizes the scalability of a structural digital signature to attain a satisfactory equilibrium between security and picture *** effective adaptive compression strategy was created to lengthen the overall lifetime of the network by sharing the processing of *** scheme ensures a large reduction in computational and energy requirements while minimizing image quality *** approach employs multi-scale characteristics to improve the resistance of signatures against image *** proposed system attained a Gaussian noise value of 98%and a rotation accuracy surpassing 99%.

关键词： Image transmission image compression text hiding Bezier curve histogram of Oriented Gradients(hOG) LSTM image enhancement Gaussian noise rotation

A hydrodynamic modelling of wave-activated bodies for wavelet marine regions

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Clean Energy 2024年第2期8卷 35-47页

作者： J.S.Peh Mohammed W.Muhieldeen N.h.Shuaib Mechanical Engineering Department Faculty of EngineeringTechnology&Built EnvironmentUCSI UniversityKuala Lumpur56000Malaysia MTC Engineer Sdn.Bhd Shah AlamSelangorMalaysia

Recently,most wave energy research has targeted sea areas with high power density under extreme wave conditions for *** trend often leads to higher energy costs for wave power ***,many marine areas with low power density,characterized by wavelet conditions and less destructive forces than extreme wave conditions,remain ***,this study aimed to propose a wave-activated body model for sea regions with wavelet *** wave-activated body design process encompassed site selection,parameter determination,geometry design,comparison and performance evaluation using the ANSYS®AQWA *** results indicated that the proposed device achieved the desired heave motion,with an amplitude range of 1.2 to-2.5 m,validating its potential for deployment in marine regions with wavelet ***,while the proposed design is optimized for wavelet conditions,it was found to have potential limitations in extreme wave *** observation emphasizes the challenge of formulating a generalized design suitable for both ***,it is pivotal for wave-activated body designs to be customized based on the specific ocean conditions they target,underscoring the need for specialized designs of wave energy converters that consider the unique wave characteristics of their deployment sites.

关键词： wave energy converter South China sea renewable and sustainable energy wavelet ANSYS AQWA hydrodynamic wave-activated bodies

Residue Based Open-Loop Modal Analysis Method for Detecting LFMR of PMSG-WFs Penetrated Power Systems

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CSEE Journal of Power and Energy Systems 2024年第4期10卷 1454-1465页

作者： Luonan Qiu Tianhao Wen Yang Liu Q.h.Wu School of Electric Power Engineering South China University of TechnologyGuangzhou510640China

This paper proposes a residue based open-loop modal analysis method to detect low frequency modal resonance(LFMR),including asymmetric low frequency modal attraction(ALFMA)and asymmetric low frequency modal repulsion(ALFMR),of permanent magnetic synchronous generator based wind farms(PMSG-WFs)penetrated power *** formation of ALFMA and ALFMR caused by two open-loop low frequency oscillation(LFO)modes moving close and apart is analyzed in *** predicting the trajectories of closed-loop LFO modes based on calculation of residue of open-loop LFO modes,both ALFMA and ALFMR can be *** proposed method can select LFO modes which move to the right half complex plane as control parameters *** studies are carried out on a three-machine power system and a four-machine 11-bus power system to verify the properties of the proposed method.

关键词： Asymmetric low frequency modal attraction asymmetric low frequency modal repulsion low frequency modal resonance residue based open-loop modal analysis method

hepatocardiorenal syndrome in liver cirrhosis:Recognition of a new entity?

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World Journal of Gastroenterology 2024年第2期30卷 128-136页

作者： henry h L Wu Amina Rakisheva Arvind Ponnusamy Rajkumar Chinnadurai Renal Research Kolling Institute of Medical ResearchRoyal North Shore Hospital&The University of SydneySt.Leonards(Sydney)2065New South WalesAustralia Department of Cardiology City Cardiological CenterAlmaty 050000Kazakhstan Department of Renal Medicine Royal Preston HospitalPreston PR29HTUnited Kingdom Donal O’Donoghue Renal Research Centre&Department of Renal Medicine Northern Care Alliance National Health Service Foundation TrustSalford M68HDUnited Kingdom

Emerging evidence and perspectives have pointed towards the heart playing an important role in hepatorenal syndrome(hRS),outside of conventional understanding that liver cirrhosis is traditionally considered the sole origin of a cascade of pathophysiological mechanisms directly affecting the kidneys in this *** the absence of established heart disease,cirrhotic cardiomyopathy may occur more frequently in those with liver cirrhosis and kidney *** is a specific form of cardiac dysfunction characterized by blunted contractile responsiveness to stress stimuli and altered diastolic relaxation with electrophysiological *** the clinical description of these potential cardiac-related complications of the liver,the role of the heart has traditionally been an overlooked aspect of circulatory dysfunction in *** from a physiological sense,temporality(prior onset)of cardiorenal interactions in hRS and positive effects stemming from portosystemic shunting demonstrated an important role of the heart in the development and progression of kidney dysfunction in cirrhotic *** this review,we discuss current concepts surrounding how the heart may influence the development and progression of hRS,and the role of systemic inflammation and endothelial dysfunction causing circulatory dysfunction within this *** temporality of heart and kidney dysfunction in hRS will be *** a subgroup of patients who receive portosystemic shunting,the dynamics of cardiorenal interactions following treatment is *** research to determine the unknowns in this topic is anticipated,hopefully to further clarify the intricacies surrounding the liver-heart-kidney connection and improve strategies for management.

关键词： hepatorenal syndrome Cardiorenal syndrome Cirrhosis Cardiac dysfunction Circulatory dysfunction

Effects of Transjugular Intrahepatic Portosystemic Shunt on Renal and Pulmonary Function in hepatic Decompensation with and without hepatorenal and hepatopulmonary Syndromes:A Review

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Journal of Clinical and Translational hepatology 2024年第9期12卷 780-791页

作者： Ahmed h.Abdelwahed Moataz Aboeldahb George Y.Wu Department of Medicine Division of Gastroenterology-HepatologyUniversity of Connecticut Health CenterFarmingtonCTUSA Department of Gastroenterology and hepatology Mayo ClinicRochesterMNUSA

Cirrhosis is often characterized by decreased liver function,ranging from a compensated,typically asymptomatic phase to a decompensated phase characterized by the appearance of ascites or variceal bleeding,and ultimately hepatorenal syndrome(hRS)or hepatopulmonary syndrome(hPS).The latter two complications are associated with a poor prognosis and limited treatment *** cases of ascites or variceal bleeding resistant to medical therapy,transjugular intrahepatic portosystemic shunt(TIPS)is effective and *** blood by TIPS diverts portal blood to the systemic circulation,potentially increasing systemic blood volume and benefiting renal ***,TIPS could also divert nitric oxide to the systemic circulation,potentially worsening systemic hypotension and perfusion,which could be detrimental to renal *** evidence indicates that TIPS often improves renal function in patients with portal hypertension,with or without *** studies have shown persistently decreased renal function after ***,these data are insufficient to support a recommendation for the use of TIPS specifically for *** patients without pre-existing hPS,TIPS does not appear to significantly affect pulmonary gas *** of TIPS in hPS have been inconsistent;some studies have shown improvement,but effects were *** studies have shown a persistent decline in pulmonary function after *** evidence supports the need for large randomized controlled trials to investigate the beneficial effects of TIPS for *** pulmonary function data are less clear regarding TIPS for *** aim of the current report was to review the literature regarding the effects of TIPS on renal and pulmonary function in hepatic decompensation,with or without the development of hRS or hPS.

关键词： Cirrhosis hepatorenal syndrome hepatopulmonary syndrome Transjugular intrahepatic portosystemic shunt

Deep learning-based detection of indicator species for monitoring biodiversity in semi-natural grasslands

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Environmental Science and Ecotechnology 2024年第5期21卷 238-247页

作者： Deepak h.Basavegowda Inga Schleip Paul Mosebach Cornelia Weltzien Technische Universitat Berlin Straße des 17.Juni 13510623BerlinGermany Leibniz-Institut für Agrartechnik und Biookonomie e.V.(ATB) Max-Eyth-Allee 10014469PotsdamGermany hochschule für nachhaltige Entwicklung Eberswalde Schicklerstraße 516225EberswaldeGermany

Deep learning(DL)has huge potential to provide valuable insights into biodiversity changes in speciesrich agricultural ecosystems such as semi-natural grasslands,helping to prioritize and plan conservation ***,DL has been underexplored in grassland conservation efforts,hindered by data scarcity,intricate ecosystem interactions,and limited economic ***,we developed a DL-based object-detection model to identify indicator species,a group of vascular plant species that serve as surrogates for biodiversity assessment in high nature value(hNV)*** selected indicator species Armeria maritima,Campanula patula,Cirsium oleraceum,and Daucus *** overcome the hurdle of limited data,we grew indicator plants under controlled greenhouse conditions,generating a sufficient dataset for DL model *** model was initially trained on this greenhouse ***,smaller datasets derived from an experimental grassland plot and natural grasslands were added to the training to facilitate the transition from greenhouse to field *** optimized model achieved remarkable average precision(AP)on test datasets,with 98.6 AP50 on greenhouse data,98.2 AP50 on experimental grassland data,and 96.5 AP50 on semi-natural grassland *** findings highlight the innovative application of greenhouse-grown specimens for the in-situ identification of plants,bolstering biodiversity monitoring in grassland ***,the study illuminates the promising role of DL techniques in conservation programs,particularly as a monitoring tool to support result-based agrienvironment schemes.

关键词： Species-rich grasslands Biodiversity monitoring Object detection Cross-domain knowledge transfer

Pelleting and particle size reduction of corn increase net energy and digestibility of fiber,protein,and fat in corn-soybean meal diets fed to group-housed pigs

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Journal of Animal Science and Biotechnology 2024年第4期15卷 1751-1760页

作者： Su A Lee Diego A.Rodriguez Chad B.Paulk hans h.Stein Department of Animal Sciences University of IllinoisUrbanaIL 61801USA Department of Grain Sciences and Industry Kansas State UniversityManhattanKS 66506USA

Background Reduction of the particle size of corn increases energy digestibility and concentrations of digestible and metabolizable *** may also reduce particle size of grain,but it is not known if there are interactions between particle size reduction and *** objective of this experiment was to test the hypothesis that particle size reduction and pelleting,separately or in combination,increase N balance,apparent total tract digestibility(ATTD)of fiber and fat,and net energy(NE)in corn-soybean meal diets fed to group-housed *** Six corn-soybean meal-based diets were used in a 3×2 factorial design with 3 particle sizes of corn(i.e.,700,500,or 300μm)and 2 diet forms(i.e.,meal or pelleted).Pigs were allowed ad libitum access to feed and ***-four castrated male pigs(initial weight:29.52 kg;standard diviation:1.40)were allotted to the 6 diets using a 6×6 Latin square design with 6 calorimeter chambers(i.e.,4 pigs/chamber)and 6 *** consumption and CO_(2)and Ch_(4)productions were measured during fed and fasting states and fecal and urine samples were *** Regardless of particle size of corn,the ATTD of gross energy(GE),N,and acid-hydrolyzed ether extract(AEE),and the concentration of NE were greater(Phan in meal *** of diet form,the ATTD of GE,N,and AEE,and the concentration of NE were increased(linear;Phe particle size of corn,but the increase was greater in meal diets than in pelleted diets(interaction;Ph pelleting and reduction of corn particle size increased nutrient digestibility and NE,but increases were greater in meal diets than in pelleted diets.

关键词： Corn Digestibility Feed technology Net energy Particle size Pelleting

Search for production of dark fermion candidates in association with heavy neutral gauge boson decaying to dimuon in proton-proton collisions at√s=8 TeV using CMS open data

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Chinese Physics C 2024年第4期48卷 6-13页

作者： Y.Mahmoud h.Abdallah M.T.hussein S.Elgammal Centre for theoretical physics The British University in EgyptEgypt Physics Department Faculty of ScienceCairo UniversityEgypt

In this study,we conducted a search for dark matter using a part of the data recorded by the CMS experiment during run-I of the LhC in 2012 with a center of mass energy of 8 TeV and an integrated luminosity of 11.6 fb−*** data were gathered from the CMS open *** matter,in the framework of the simplified model(mono-Z′),can be produced from proton-proton collisions in association with a new hypothetical gauge boson,Z′.Thus,the search was conducted in the dimuon plus large missing transverse momentum *** benchmark scenario of mono-Z′,which is known as light vector,was used for interpreting the CMS open *** evidence of dark matter was observed,and exclusion limits were set on the masses of dark matter and Z′at 95%confidence level.

关键词： dark matter large hadron collider CMS open data search for new physics dark fermion