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Nonlinear wave dispersion in monoatomic chains with lumped and distributed masses:discrete and continuum models

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Applied Mathematics and Mechanics(english edition) 2024年第4期45卷 633-648页

作者： e.GHAVANLOO S.eL-BOrGI School of Mechanical engineering Shiraz UniversityShiraz 71963-16548Iran Mechanical engineering Program Texas A&M University at QatarDoha 23874Qatar

The main objective of this paper is to investigate the influence of inertia of nonlinear springs on the dispersion behavior of discrete monoatomic chains with lumped and distributed *** developed model can represent the wave propagation problem in a non-homogeneous material consisting of heavy inclusions embedded in a *** inclusions are idealized by lumped masses,and the matrix between adjacent inclusions is modeled by a nonlinear spring with distributed ***,the model is capable of depicting the wave propagation in bi-material bars,wherein the first material is represented by a rigid particle and the second one is represented by a nonlinear spring with distributed *** discrete model of the nonlinear monoatomic chain with lumped and distributed masses is first considered,and a closed-form expression of the dispersion relation is obtained by the second-order Lindstedt-Poincare method(LPM).Next,a continuum model for the nonlinear monoatomic chain is derived directly from its discrete lattice model by a suitable continualization *** subsequent use of the second-order method of multiple scales(MMS)facilitates the derivation of the corresponding nonlinear dispersion relation in a closed *** novelties of the present study consist of(i)considering the inertia of nonlinear springs on the dispersion behavior of the discrete mass-spring chains;(ii)developing the second-order LPM for the wave propagation in the discrete chains;and(iii)deriving a continuum model for the nonlinear monoatomic chains with lumped and distributed ***,a parametric study is conducted to examine the effects of the design parameters and the distributed spring mass on the nonlinear dispersion relations and phase velocities obtained from both the discrete and continuum *** parameters include the ratio of the spring mass to the lumped mass,the nonlinear stiffness coefficient of the spring,and the wave amplitude.

关键词： nonlinear mass-spring chain discrete model continuum model LindstedtPoincare method(LPM) method of multiple scales(MMS) dispersion phase velocity

Annual variation of adult survival of a south-temperate House Wren population in Argentina

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Avian research 2024年第2期15卷 229-237页

作者： Gustavo J.Fernandez Mariana e.Carro Paulo e.Llambías Grupo de Investigacion en ecofisiología de Fauna Silvestre INIBIOMA-CONICETAsentamiento Universitario San Martín de los Andes(AUSMA)Universidad Nacional Del ComahuePasaje de la Paz 235(8370)San Martín de los AndesNeuquenArgentina Grupo de Investigacion de Biología de Aves IADIZA CCT-MendozaUniversidad Nacional de CuyoAvenida RuizLeal s/n Parque General San Martin5500MendozaArgentina

Identifying factors affecting the survival of individuals is essential for understanding the evolution of life-history traits and population *** numerous studies on this subject in north-temperate environments,there is a lack of equivalent studies at similar latitudes in the ***,we used a 14-year dataset of capture,banding,and resighting to estimate the annual variation in the apparent adult survival probability of a south-temperate population of House Wrens(Troglodytes aedon bonariae).We evaluated temporal variation in sur-vival and the effect of environmental(climatic)and demographic variables(adult abundance,total number of fledglings produced during each breeding season)on survival *** found that the probability of adult survival decreased as the abundance of breeding adults *** density-dependent effect could be related to the resident lifestyle of southern House Wrens,which could determine an intense competition for territories and resources that ultimately would affect their survival.

关键词： Annual variation CJS Density-dependence Survival Troglodytes aedon bonariae

An efficient Long Short-TermMemory and Gated recurrent Unit Based Smart Vessel Trajectory Prediction Using Automatic Identification System Data

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Computers, Materials and Continua 2024年第1期81卷 1789-1808页

作者： Zaman U. Khan J. Lee e. Hussain S. Balobaid A.S. Aburasain r.Y. Kim K. Department of Computer engineering Chungnam National University Daejeon 34134 South Korea Department of environmental IT engineering Chungnam National University Daejeon 34134 South Korea Autonomous Ship research Center Samsung Heavy Industries Daejeon 34051 South Korea ICArOS Center (PrISMA Lab) University of Naples Federico II Naples 80131 Italy Department of Computer Science College of Computer Science and Information Technology Jazan University Jazan 45142 Saudi Arabia

Maritime transportation, a cornerstone of global trade, faces increasing safety challenges due to growing sea traffic volumes. This study proposes a novel approach to vessel trajectory prediction utilizing Automatic Identification System (AIS) data and advanced deep learning models, including Long Short-Term Memory (LSTM), Gated recurrent Unit (GrU), Bidirectional LSTM (DBLSTM), Simple recurrent Neural Network (SimplerNN), and Kalman Filtering. The research implemented rigorous AIS data preprocessing, encompassing record deduplication, noise elimination, stationary simplification, and removal of insignificant trajectories. Models were trained using key navigational parameters: latitude, longitude, speed, and heading. Spatiotemporal aware processing through trajectory segmentation and topological data analysis (TDA)was employed to capture dynamic *** using a three-month AIS dataset demonstrated significant improvements in prediction accuracy. The GrU model exhibited superior performance, achieving training losses of 0.0020 (Mean Squared error, MSe) and 0.0334 (Mean Absolute error, MAe), with validation losses of 0.0708 (MSe) and 0.1720 (MAe). The LSTM model showed comparable efficacy, with training losses of 0.0011 (MSe) and 0.0258 (MAe), and validation losses of 0.2290 (MSe) and 0.2652 (MAe). Both models demonstrated reductions in training and validation losses, measured by MAe, MSe, Average Displacement error (ADe), and Final Displacement error (FDe). This research underscores the potential of advanced deep learning models in enhancing maritime safety through more accurate trajectory predictions, contributing significantly to the development of robust, intelligent navigation systems for the maritime industry. © 2024 The Authors. Published by Tech Science Press.

关键词： AIS data deep learning GrU LSTM smart vessel Trajectory prediction

Graphene-calcium carbonate coating to improve the degradation resistance and mechanical integrity of a biodegradable implant

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Journal of Magnesium and Alloys 2024年第1期12卷 394-404页

作者： Lokesh Choudhary Parama Chakraborty Banerjee r.K.Singh raman Derrek e.Lobo Christopher D.easton Mainak Majumder Frank Witte Jörg F.Löffler Department of Mechanical and Aerospace engineering Monash UniversityClayton CampusMelbourneVIC 3800Australia Department of Chemical and Biological engineering Monash UniversityClayton CampusMelbourneVIC 3800Australia Nanoscale Science and engineering Laboratory(NSeL) Bldg 37Monash UniversityClayton CampusMelbourneVIC 3800Australia CSIrO Materials Science and engineering Bayview AvenueClaytonVIC 3168Australia Julius Wolff Institute and Berlin Brandenburg Center for regenerative Therapies Charité–Universitätsmedizin BerlinAugustenburger Platz 113353 BerlinGermany Laboratory of Metal Physics and Technology Department of MaterialsETH Zurich8093 ZurichSwitzerland

Biodegradable implants are critical for regenerative orthopaedic procedures,but they may suffer from too fast corrosion in human-body *** necessitates the synthesis of a suitable coating that may improve the corrosion resistance of these implants without compromising their mechanical *** this study,an AZ91 magnesium alloy,as a representative for a biodegradable Mg implant material,was modified with a thin reduced graphene oxide(rGO)-calcium carbonate(CaCO_(3))composite *** analytical and in-vitro electrochemical characterization reveals that this coating significantly improves the corrosion resistance and mechanical integrity,and thus has the potential to greatly extend the related application field.

关键词： Graphene coating Biodegradable implant Hydroxyapatite Corrosion Magnesium alloy

Beyond p-y method:A review of artificial intelligence approaches for predicting lateral capacity of drilled shafts in clayey soils

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Journal of rock Mechanics and Geotechnical engineering 2024年第9期16卷 3812-3840页

作者： M.e.Al-Atroush A.e.Aboelela ezz el-Din Hemdan Civil and environmental engineering Program Engineering Management DepartmentCollege of EngineeringPrince Sultan UniversityRiyadhSaudi Arabia Department of Structural engineering Faculty of EngineeringAin Shams UniversityCairoEgypt Structure and Materials research Lab Prince Sultan UniversityRiyadhSaudi Arabia Computer Science and engineering Department Faculty of Electronic EngineeringMenoufia UniversityMenoufiaEgypt

In 2023,pivotal advancements in artificial intelligence(AI)have significantly *** that in mind,traditional methodologies,notably the p-y approach,have struggled to accurately model the complex,nonlinear soil-structure interactions of laterally loaded large-diameter drilled *** study undertakes a rigorous evaluation of machine learning(ML)and deep learning(DL)techniques,offering a comprehensive review of their application in addressing this geotechnical challenge.A thorough review and comparative analysis have been carried out to investigate various AI models such as artificial neural networks(ANNs),relevance vector machines(rVMs),and least squares support vector machines(LSSVMs).It was found that despite ML approaches outperforming classic methods in predicting the lateral behavior of piles,their‘black box'nature and reliance only on a data-driven approach made their results showcase statistical robustness rather than clear geotechnical insights,a fact underscored by the mathematical equations derived from these ***,the research identified a gap in the availability of drilled shaft datasets,limiting the extendibility of current findings to large-diameter *** extensive dataset,compiled from a series of lateral loading tests on free-head drilled shaft with varying properties and geometries,was introduced to bridge this *** paper concluded with a direction for future research,proposes the integration of physics-informed neural networks(PINNs),combining data-driven models with fundamental geotechnical principles to improve both the interpretability and predictive accuracy of AI applications in geotechnical engineering,marking a novel contribution to the field.

关键词： Laterally loaded drilled shaft load transfer and failure mechanisms Physics-informed neural networks(PINNs) P-y curves Artificial intelligence(AI) Dataset

Converting Trex-rGB green-channel data to 557.7 nm auroral intensity:Methodology and initial results

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earth and Planetary Physics 2024年第1期8卷 258-274页

作者： Jun Liang D.M.Gillies e.Spanswick e.F.Donovan University of Calgary CalgaryT2N 1N4Canada

The recently deployed Transition region explorer(Trex)-rGB(red-green-blue)all-sky imager(ASI)is designed to capture“true color”images of the aurora and *** the 557.7 nm green line is usually the brightest emission line in visible auroras,the green channel of a Trex-rGB camera is usually dominated by the 557.7 nm *** this rationale,the Trex mission does not include a specific 557.7 nm imager and is designed to use the rGB green-channel data as a proxy for the 557.7 nm *** this study,we present an initial effort to establish the conversion ratio or formula linking the rGB green-channel data to the absolute intensity of 557.7 nm auroras,which is crucial for quantitative uses of the rGB *** illustrate two approaches:(1)through a comparison with the collocated measurement of green-line auroras from the Trex spectrograph,and(2)through a comparison with the modeled green-line intensity according to realistic electron precipitation flux measurements from low-earth-orbit satellites,with the aid of an auroral transport *** demonstrate the procedures and provide initial results for the Trex-rGB ASIs at the rabbit Lake and Lucky Lake *** rGB response is found to be *** conversion ratios or formulas between rGB green-channel data and the green-line auroral intensity are given and can be applied immediately by Trex-rGB data *** methodology established in this study will also be applicable to the upcoming SMILe ASI mission,which will adopt a similar rGB camera system in its deployment.

关键词： Trex rGB green-line aurora auroral transport model

Advances in spinal cord injury:insights from non-human primates

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Neural regeneration research 2024年第11期19卷 2354-2364页

作者： Gaetan Poulen Florence e.Perrin University of Montpellier INSERMEPHEMontpellierFrance Department of Neurosurgery Gui de Chauliac HospitalMontpellier University Medical CenterMontpellierFrance Institut Universitaire de France(IUF) ParisFrance

Spinal cord injury results in significant sensorimotor deficits,currently,there is no curative treatment for the symptoms induced by spinal cord *** and pre-clinical research on spinal cord injury relies on the development and characterization of appropriate animal *** models should replicate the symptoms observed in human,allowing for the exploration of functional deficits and investigation into various aspects of physiopathology of spinal cord ***-human primates,due to their close phylogenetic association with humans,share more neuroanatomical,genetic,and physiological similarities with humans than ***,the responses to spinal cord injury in nonhuman primates most likely resemble the responses to traumatism in *** this review,we will discuss nonhuman primate models of spinal cord injury,focusing on in vivo assessments,including behavioral tests,magnetic resonance imaging,and electrical activity recordings,as well as ex vivo histological ***,we will present therapeutic strategies developed in non-human primates and discuss the unique specificities of non-human primate models of spinal cord injury.

关键词： behavior cellular analysis non-human primates spinal cord injury tissue analysis

On Differential equations of Integrable Billiard Tables

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Acta Mathematica Sinica,english Series 2024年第1期40卷 417-424页

作者： Vladimir DrAGOVIC Andrey e.MIrONOV Department of Mathematical Sciences The University of Texas at DallasRichardson TXUSA Mathematical Institute SANU BelgradeSerbia Novosibirsk State University NovosibirskRussia Sobolev Institute of Mathematics of the Siberian Branch of the russian Academy of Sciences NovosibirskRussia

We introduce a method to find differential equations for functions which define tables,such that associated billiard systems admit a local first *** illustrate this method in three situations:the case of(locally)integrable wire billiards,for finding surfaces in r^(3)with a first integral of degree one in velocities,and for finding a piece-wise smooth surface in r^(3)homeomorphic to a torus,being a table of a billiard admitting two additional first integrals.

关键词： Polynomial first integrals wire billiards piece-wise smooth surfaces

The delivery of N-myc downstream-regulated gene 2(NDrG2)self-amplifying mrNA via modified lipid nanoparticles as a potential treatment for drug-resistant and metastatic cancers

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Medical review 2024年第3期4卷 235-238页

作者： Sandra e.reznik Amit K.Tiwari Vivek Chavda Charles r.Ashby Jr. Department of Pharmaceutical Sciences College of Pharmacy and Health SciencesSt.John’s UniversityQueensUSA Departments of Pathology and Obstetrics and Gynecology and Women’s Health Montefiore Medical Center/Albert Einstein College of MedicineBronxUSA Department of Pharmaceutical Sciences College of Pharmacy University of Arkansas for Medical Sciences Little RockUSA Department of Pharmaceutics and Pharmaceutical Technology L.M.College of Pharmacy AhmedabadIndia Department of Pharmaceutical Sciences College of Pharmacy and Health SciencesSt.John’s UniversityQueensNY 11439USA

The protein,N-myc downstream-regulated gene 2(NDrG2),a tumor suppressor,is significantly decreased or absent in many types of *** is a significant negative correlation between the levels of NDrG2 and the development and progression of cancer tumor recurrence and tumor invasion,in different *** contrast,the in vitro and in vivo overexpression of the NDrG2 protein decreases the proliferation,growth,adhesion and migration of many types of cancer *** in vitro overexpression of NDrG2 increases the efficacy of certain anticancer drugs in specific types of cancer *** hypothesize that the delivery of the mrNA of the NDrG2 protein,encapsulated by lipid nanoparticles,could represent a potential treatment of metastatic and drug-resistant *** would be accomplished using a self-amplifying mrNA that encodes the NDrG2 protein and an rNA-dependent-rNA polymerase,obtained from an in vitrotranscribed(IVT)*** IVT mrNA would be encapsulated in a lipid *** efficacy of the nanoformulation would be determined in cultured cancer cells and if the results are positive,nude mice transplanted with either drug-resistant or metastatic drug-resistant cancer cells,would be treated with the nanoformulation and monitored for efficacy and adverse *** the appropriate preclinical studies indicate this formulation is efficacious and safe,it is possible it could be evaluated in clinical trials.

关键词： N-myc downstream-regulated gene 2(NDrG2) cancer self-amplifying mrNA nanoparticle