检索结果-南通市图书馆

Estimating the frequency of traffic overloading on road bridges

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Traffic and Transportation Engineering(English Edition) 2024年第4期11卷 776-796页

作者： roberto Ventura Benedetto Barabino Giulio Maternini Department of Civil EnvironmentalArchitectural Engineering and MathematicsUniversity of BresciaBrescia 25123Italy

Load limits,which appear to be routinely exceeded by trucks,occasionally result in road bridge ***,predicting failures is crucial for safeguarding road *** studies have largely focused on forecasting bridge failure event probability using the reliability analysis method,whilst occasionally accounting for vehicular overloading *** recently,a study has investigated design traffic overloading event frequency using generalised linear regression models(GLRMs),including a power component and negative binomial regressions(NBRs).However,as far as the authors know,artificial neural network models(ANNMs)have never been applied to this *** paper is an attempt to fill in these *** a frequencybased metric of traffic overloading was adopted as a driver of failure ***,two alternative‘frequency'models were specified,calibrated,and *** former was based on a GLRM,the latter on ***,these models were compared using regression plots(RPs),measures of errors(Mo Es)and the ratio between the number of observed vs predicted design load overcoming events to evaluate their *** models analysed more than 2 million weigh-in-motion(WIM)data records from a pilot station on a bridge on a heavily used ring road in Brescia(Italy).Results showed that ANNMs outperformed *** have a higher correlation coefficient(between predicted and target frequencies),lower Mo Es,and a closer-to-unity ratio(between predicted and target frequencies).These findings may increase prediction accuracy of design traffic overloading events and give road authorities more effective traffic management to protect bridges from load hazards.

关键词： Road bridges Traffic load hazard Econometry Machine learning Weigh-in-motion Big-data analysis

Perturbed initial orbit determination

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Astrodynamics 2024年第3期8卷 401-416页

作者： Alberto Fossà Matteo Losacco roberto Armellin Institut Supérieur de l’Aéronautique et de l’Espace Toulouse31400France Te PūnahaĀtea-Space Institute The University of AucklandAuckland1010New Zealand

An algorithm for robust initial orbit determination (IOD) under perturbed orbital dynamics is presented. By leveraging map inversion techniques defined in the algebra of Taylor polynomials, this tool returns a highly accurate solution to the IOD problem and estimates a range centered on the aforementioned solution in which the true orbit should lie. To meet the specified accuracy requirements, automatic domain splitting is used to wrap the IOD routines and ensure that the local truncation error, introduced by a polynomial representation of the state estimate, remains below a predefined threshold. The algorithm is presented for three types of ground-based sensors, namely range radars, Doppler-only radars, and optical telescopes, by considering their different constraints in terms of available measurements and sensor noise. Finally, the improvement in performance with respect to a Keplerian-based IOD solution is demonstrated using large-scale numerical simulations over a subset of tracked objects in low Earth orbit.

关键词： initial orbit determination(IOD) range radar Doppler radar optical telescope differential algebra(DA)

Assessment of compressive strength of jet grouting by machine learning

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2024年第1期16卷 102-111页

作者： Esteban Diaz Edgar Leonardo Salamanca-Medina roberto Tomas Departamento de Ingeniería Civil Escuela Politécnica SuperiorUniversidad de AlicanteP.O.Box 99E-03080AlicanteSpain

Jet grouting is one of the most popular soil improvement techniques,but its design usually involves great uncertainties that can lead to economic cost overruns in construction *** high dispersion in the properties of the improved material leads to designers assuming a conservative,arbitrary and unjustified strength,which is even sometimes subjected to the results of the test *** present paper presents an approach for prediction of the uniaxial compressive strength(UCS)of jet grouting columns based on the analysis of several machine learning algorithms on a database of 854 results mainly collected from different research *** selected machine learning model(extremely randomized trees)relates the soil type and various parameters of the technique to the value of the compressive *** the complex mechanism that surrounds the jet grouting process,evidenced by the high dispersion and low correlation of the variables studied,the trained model allows to optimally predict the values of compressive strength with a significant improvement with respect to the existing ***,this work proposes for the first time a reliable and easily applicable approach for estimation of the compressive strength of jet grouting columns.

关键词： Jet grouting Ground improvement Compressive strength Machine learning

A comprehensive analysis of future solar energy potential variations using a CMIP6 multi-model ensemble approach in Colombia

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Clean Energy 2024年第4期8卷 79-89页

作者： Heli AArregocés roberto Rojano Daiver Pinto Pimienta Grupo de Investigación GISA Facultad de IngenieríaUniversidad de La GuajiraRiohachaColombia Grupo Procesos Fisicoquímicos Aplicados Facultad de IngenieríaUniversidad de Antioquia SIU/UdeACalle 70 No.52–21MedellínColombia Grupo Desarrollo de Estudios y Tecnologías Ambientales del Carbono(DESTACAR) Facultad de IngenieríaUniversidad de La GuajiraRiohachaColombia

Climate change is predicted to significantly impact solar energy generation,which is particularly concerning given that photovoltaic(PV)energy is critical to the global transition to clean energy in underdeveloped *** study analyses the PV potential variations in Colombia using a Coupled Model Intercomparison Project Phase 6(CMIP6)multi-model ensemble approach under two shared socio-economic pathway scenarios for the near(2025-50)and far(2051-2100)*** the near-future period,the Pacific,Andean and Orinoquía regions are expected to experience a decrease in PV potential ranging from 10%to 23%for all shared socio-economic *** will be particularly noticeable during the March/April/May and June/July/August *** the other hand,CMIP6 estimations indicate a 1-4%increase in PV potential across the Amazon region during the June/July/August and September/October/November *** the far future,it has been projected that the Pacific,Andean and Orinoquía regions may experience a significant decline in solar power generation due to increased cloud cover and reduced *** decrease in PV potential during the June/July/August season could range from 8%to 27%for all considered scenarios,with the Pacific region being the most *** Pacific region is projected to experience a decrease ranging from 10%to 35%for all *** is worth noting that there are noticeable differences in PV potential across various regions,which can result in changes in cloud cover and atmospheric ***,the study provides valuable insights into the PV potential in Colombia and highlights the importance of considering regional variations and climate change scenarios in future energy planning.

关键词： photovoltaic potential CMIP6 solar photovoltaic energy climate change Colombia

A high aspect ratio surface micromachined accelerometer based on a SiC-CNT composite material

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Microsystems & Nanoengineering 2024年第2期10卷 219-230页

作者： Jiarui Mo Shreyas Shankar roberto Pezone Guoqi Zhang Sten Vollebregt Laboratory of Electronic Components Technology and Materials(ECTM)Department of MicroelectronicsDelft University of TechnologyDelftThe Netherlands

Silicon carbide(SiC)is recognized as an excellent material for microelectromechanical systems(MEMS),especially those operating in challenging environments,such as high temperature,high radiation,and corrosive ***,SiC bulk micromachining is still a challenge,which hinders the development of complex SiC *** address this problem,we present the use of a carbon nanotube(CNT)array coated with amorphous SiC(a-SiC)as an alternative composite material to enable high aspect ratio(HAR)surface *** using a prepatterned catalyst layer,a HAR CNT array can be grown as a structural template and then densified by uniformly filling the CNT bundle with LPCVD *** electrical properties of the resulting SiC-CNT composite were characterized,and the results indicated that the electrical resistivity was dominated by the *** demonstrate the use of this composite in MEMS applications,a capacitive accelerometer was designed,fabricated,and *** fabrication results showed that the composite is fully compatible with the manufacturing of surface micromachining *** Young’s modulus of the composite was extracted from the measured spring constant,and the results show a great improvement in the mechanical properties of the CNTs after coating with *** accelerometer was electrically characterized,and its functionality was confirmed using a mechanical shaker.

关键词： composite surface electrical

How can the holder trust the verifier?A CP-ABPRE-based solution to control the access to claims in a Self-Sovereign-Identity scenario

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Blockchain(Research and Applications) 2024年第3期5卷 22-41页

作者： Francesco Buccafurri Vincenzo De Angelis roberto Nardone University of Reggio Calabria 89124 Reggio CalabriaItaly University of Calabria 87036 Arcavacata di Rende(CS)Italy University of Naples“Parthenope” 80143 NaplesItaly

The interest in Self-Sovereign Identity(SSI)in research,industry,and governments is rapidly *** is a paradigm where users hold their identity and credentials issued by authorized *** is revolutionizing the concept of digital identity and enabling the definition of a trust framework wherein a service provider(verifier)validates the claims presented by a user(holder)for accessing ***,current SSI solutions primarily focus on the presentation and verification of claims,overlooking a dual aspect:ensuring that the verifier is authorized to access the holder’s *** this gap,this paper introduces an innovative SSI-based solution that integrates decentralized wallets with Ciphertext-Policy Attribute-Based Proxy Re-Encryption(CP-ABPRE).This combination effectively addresses the challenge of verifier *** solution,implemented on the Ethereum platform,enhances accountability by notarizing key operations through a smart *** paper also offers a prototype demonstrating the practicality of the proposed ***,it provides an extensive evaluation of the solution’s performance,emphasizing its feasibility and efficiency in real-world applications.

关键词： Blockchain IPFS Self Sovereign Identity Smart contract Access control

Double-nylon purse-string suture technique: Another addition to the endoscopist's toolbox for full-thickness defect closure

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2024年第25期30卷 3152-3154页

作者： Angad Walia roberto Paolo Trasolini Neal Shahidi Department of Medicine University of British ColumbiaVancouver V6Z2K5BCCanada

Iatrogenic perforation is the most feared adverse event in *** the expansion of interventional endoscopy in favor of traditional surgery,it is now more crucial than ever to develop effective defect closure *** has culminated in the dissemination of multiple novel closure technologies,including through-the-scope clips,over-the-scope clips,through-the-scope suturing and over-the-scope suturing *** this editorial,we comment on the recent publication by Wang and colleagues discussing the performance of the double-nylon purse-string suture technique in the closure of large(>3 cm)gastric full-thickness *** technique offers a promising,practical and cost-effective approach to closure of large full-thickness defects that can be readily imple-mented across diverse healthcare settings.

关键词： Cancer Endoscopy Endoscopic full-thickness resection Perforation

Wind power potential over northern South America using ERA5-Land global reanalysis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Clean Energy 2024年第2期8卷 104-112页

作者： Heli A.Arregocés Guillermo J.Bonivento roberto Rojano Grupo de Investigación GISA Facultad de IngenieríaUniversidad de La GuajiraRiohachaColombia Grupo Procesos Fisicoquímicos Aplicados Facultad de IngenieríaUniversidad de Antioquia SIU/UdeACalle 70 No.52-21MedellínColombia

The northernmost region of South America has great potential for wind energy production and is a strategic area for the energy tran*** analysed data from ERA5-Land global reanalysis from 1980 to 2020 to determine the wind power potential in this *** aim was to identify areas with a high potential for wind energy that could be used to supply energy in case of drought in the region or increases in fuel *** compared data from 19 meteorological stations located in Colombia with ERA5-Land reanalysis data to generate reliable information for the feasibility and operation of wind *** to our analysis,the Colombian Caribbean and Coastal Plain have monthly average wind speeds at 90 m ranging from 4.85 to 10.34 m/s and 3.79 to 6.62 m/s,*** on wind power density calculations,these regions have the highest wind power density in our study,with a monthly average of between 250 and 399 W/m^(2).The Caribbean Region had a 69%increase in wind power density from January to July compared with the annual *** wind power density in the plains increased from January to March,while the Mountain Region had higher anomalies from May to *** Alta Guajira and ParaguanáPeninsula have great potential to generate wind energy due to their privileged geographical *** ERA5 offers valuable information about wind availability in time and space,it cannot represent the influence of local effects on wind patterns for the Mountain Region.

关键词： onshore wind power wind power potential ERA5-Land global reanalysis wind speed

An efficient improved Gradient Boosting for strain prediction in Near-Surface Mounted fiber-reinforced polymer strengthened reinforced concrete beam

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Structural and Civil Engineering 2024年第8期18卷 1148-1168页

作者： Abdelwahhab KHATIR roberto CAPOZUCCA Samir KHATIR Erica MAGAGNINI Brahim BENAISSA Thanh CUONG-LE Structural Section DICEA Polytechnic University of MarcheAncona 60131Italy Centre for Engineering Application&Technology Solutions Ho Chi Minh City Open UniversityHo Chi Minh City 70000Vietnam Design Engineering Laboratory Toyota Technological InstituteNagoya 468-8511Japan

The Near-Surface Mounted(NSM)strengthening technique has emerged as a promising alternative to traditional strengthening methods in recent *** the past two decades,researchers have extensively studied its potential,advantages,and applications,as well as related parameters,aiming at optimization of construction ***,there is still a need to explore further,both from a static perspective,which involves accounting for the nonconservation of the contact section resulting from the bond-slip effect between fiber-reinforced polymer(FRP)rods and resin and is typically neglected by existing analytical models,as well as from a dynamic standpoint,which involves studying the trends of vibration frequencies to understand the effects of various forms of damage and the efficiency of *** address this gap in knowledge,this research involves static and dynamic tests on simply supported reinforced concrete(RC)beams using rods of NSM carbon fiber reinforced polymer(CFRP)and glass fiber reinforced polymer(GFRP).The main objective is to examine the effects of various strengthening *** research conducts bending tests with loading cycles until failure,and it helps to define the behavior of beam specimens under various damage degrees,including concrete *** analysis by free vibration testing enables tracking of the effectiveness of the reinforcement at various damage levels at each stage of the loading *** addition,application of Particle Swarm Optimization(PSO)and Genetic Algorithm(GA)is proposed to optimize Gradient Boosting(GB)training performance for concrete strain prediction in NSM-FRP *** GB using Particle Swarm Optimization(GBPSO)and GB using Genetic Algorithm(GBGA)systems were trained using an experimental data set,where the input data was a static applied load and the output data was the consequent *** models of GBPSO and GBGA have been shown to provide highly accurate results for predicting *** model

关键词： NSM technique fiber-reinforced polymer rods static and dynamic analysis GB PSO GA finite element analysis