检索结果-南通市图书馆

Dynamic event-triggered fault-tolerant cooperative resilient tracking control with prescribed performance for UAVs

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2024年第8期67卷 67-84页

作者： Rong YUAN Zhengcai AN Shuyi SHAO Mou CHEN Mihai lungu College of Automation Engineering Nanjing University of Aeronautics and Astronautics Science and Technology on Electro-optic Control Laboratory Faculty of Electrical Engineering University of Craiova Aerospace Engineering Doctoral School University Politehnica of Bucharest

In this paper, a resilient tracking control scheme with cooperative collision avoidance performance is studied for the fixed-wing unmanned aerial vehicle(UAV) leader-follower formation in the presence of actuator failures and external disturbances. Firstly, based on the control objectives of UAV formation tracking and collision avoidance, the transformation tracking errors are obtained using the prescribed performance control technique. Next, a fault detection mechanism is introduced to determine if there is the actuator fault. Subsequently, the event-triggered resilient fault observers are designed based on a dynamic eventtriggered mechanism to estimate actuator faults. Furthermore, the prescribed performance functions and the H∞ performance index are employed to ensure the UAV formation collision-free and mitigate the impact of disturbances. Moreover, the resilient controller is designed to minimize the effect of the perturbations for the control gain and the fault observer gain on the system. The stability of the system is also proven through the Lyapunov stability analysis, and the controller gains are calculated by solving the linear matrix ***, the validity of the proposed control strategy is demonstrated by the simulation analysis.

关键词： UAV formation cooperative collision avoidance event-triggered fault observer prescribed performance resilient control

Current Trends in the Management of Distributed Transactions in Micro-Services Architectures: A Systematic Literature Review

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Open Journal of Applied Sciences 2024年第9期14卷 2519-2543页

作者： Samuel lungu Mayumbo Nyirenda Department of Computer Studies University of Zambia Lusaka Zambia

In the evolving landscape of software engineering, Microservice Architecture (MSA) has emerged as a transformative approach, facilitating enhanced scalability, agility, and independent service deployment. This systematic literature review (SLR) explores the current state of distributed transaction management within MSA, focusing on the unique challenges, strategies, and technologies utilized in this domain. By synthesizing findings from 16 primary studies selected based on rigorous criteria, the review identifies key trends and best practices for maintaining data consistency and integrity across microservices. This SLR provides a comprehensive understanding of the complexities associated with distributed transactions in MSA, offering actionable insights and potential research directions for software architects, developers, and researchers.

关键词： Microservice Architecture Distributed Transactions Two-phase Commit (2pC)

performance, Combustion and Emission Characteristics of Oxygenated Diesel in DI Engines: A Critical Review

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 power and Energy Engineering 2024年第6期12卷 16-49页

作者： Joseph lungu Lennox Siwale Rudolph Joe Kashinga School of Engineering The Copperbelt University Riverside Campus Kitwe Zambia

The transition from non-renewable to renewable energy sources is a significant challenge of our time. In the fuel industry, oxygenated additives such as butanol are transforming conventional fuels into renewable biofuels. This technology has been utilized in reciprocating engines for decades. This paper reviews the viability of using an n-butanol blend as a short-term replacement for diesel by analyzing its physical and chemical properties, combustion, performance, and emission characteristics in compression ignition (CI) engines under various conditions, including variable load, speed, acceleration, and both stationary and transient cycles. N-Butanol exhibits higher viscosity, better lubricity, higher heating value, improved blend stability, enhanced cold-flow properties, and higher density. These factors influence spray formation, injection timing, atomization, and combustion characteristics. Its higher oxygen content improves the diffusion combustion stage and efficiency. Adding 5% and 10% n-butanol to diesel increases pressure and apparent heat release rate, slightly reduces temperature, and improves thermal efficiency, with mixed effects on CO and THC emissions and a notable decrease in particulate matter emissions. Fuel consumption increases, while the impact on NOx emissions varies. A 10% butanol blend is considered optimal for enhancing performance and reducing particulate emissions without significantly affecting NOx emissions. Blending up to 40% butanol with diesel does not require engine modifications or ECU recalibrations in engines calibrated for pure diesel. Due to its advantageous properties and performance, n-butanol is recommended as a superior alcohol-diesel blend than ethanol for short-term diesel replacement.

关键词： Diesel Engine Alcohol Additives N-Butanol Combustion and properties

Improving the radiological diagnosis of hepatic artery thrombosis after liver transplantation: Current approaches and future challenges

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 Transplantation 2024年第1期14卷 1-8页

作者： cristian Lindner Raúl Riquelme Rodrigo San Martín Frank Quezada Jorge Valenzuela Juan p Maureira Martín Einersen Department of Radiology Faculty of MedicineUniversity of ConcepciónConcepción 4030000Chile Department of Radiology Hospital Clínico Regional Guillermo Grant BenaventeConcepción 4030000Chile Department of Statistics Catholic University of MauleTalca 3460000Chile Neurovascular Unit Department of RadiologyHospital Clínico Regional Guillermo Grant BenaventeConcepción 4030000Chile

Hepatic artery thrombosis(HAT)is a devastating vascular complication following liver transplantation,requiring prompt diagnosis and rapid revascularization treatment to prevent graft *** present,imaging modalities such as ultrasound,computed tomography,and magnetic resonance play crucial roles in diagnosing *** imaging techniques have improved sensitivity and specificity for HAT diagnosis,they have limitations that hinder the timely diagnosis of this *** this sense,the emergence of artificial intelligence(AI)presents a transformative opportunity to address these diagnostic *** development of machine learning algorithms and deep neural networks has demonstrated the potential to enhance the precision diagnosis of liver transplant complications,enabling quicker and more accurate detection of *** article examines the current landscape of imaging diagnostic techniques for HAT and explores the emerging role of AI in addressing future challenges in the diagnosis of HAT after liver transplant.

关键词： Liver transplantation postoperative complications Hepatic artery Thrombosis Radiology Artificial intelligence

plant triterpenoid saponins function as susceptibility factors to promote the pathogenicity of Botrytis cinerea

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Molecular plant 2024年第7期17卷 1073-1089页

作者： Francisco J.Escaray Amelia Felipo-Benavent cristian J.Antonelli Begona Balaguer Maria pilar Lopez-Gresa pablo Vera Instituto de Biologia Molecular y Celular de plantas Universidad Politecnica de Valencia-C.S.l.CCiudad Politecnica de la InnovacionEdificio 8Eacceso GIngeniero Fausto Elios/n46022ValenciaSpain

The gray mold fungus Botrytis cinerea is a necrotrophic pathogen that causes diseases in hundreds of plant species,including high-value *** polyxenous nature and pathogenic success are due to its ability to perceive host signals in its *** this study,we found that laticifer cells of Euphorbia lathyris are a source of susceptibility factors required by *** to cause ***,poor-in-latex(pil)mutants,which lack laticifer cells,show full resistance to this pathogen,whereas lot-of-latex mutants,which produce more laticifer cells,are *** S factors are triterpenoid saponins,which are widely distributed natural products of vast structural *** downregulation of laticifer-specific oxydosqualene cyclase genes,which encode the first committed step enzymes for triterpene and,therefore,saponin biosynthesis,conferred disease resistance to ***,the Medicago truncatula Iha-1 mutant,compromised in triterpenoid saponin biosynthesis,showed enhanced ***,the application of different purified triterpenoid saponins pharmacologically complemented the diseaseresistant phenotype ofpil and hla-1 mutants and enhanced disease susceptibility in different plant *** found that triterpenoid saponins function as plant cues that signal transcriptional reprogramming in ***,leading to a change in its growth habit and infection strategy,culminating in the abundant formation of infection cushions,the multicellular appressoria apparatus dedicated to plant penetration and biomass destruction in *** together,these results provide an explanation for how plant triterpenoid saponins function as disease susceptibility factors to promote *** pathogenicity.

关键词： Euphorbia lathyris laticifer cell latex appressorium infection cushion necrotrophic fungi

Discovering genetic biomarkers for targeted cancer therapeutics with eXplainable Artificial Intelligence

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Cancer Communications 2024年第5期44卷 584-588页

作者： Debaditya Chakraborty Elizabeth Gutierrez-Chakraborty cristian Rodriguez-Aguayo Hakan Başağaoğlu Gabriel Lopez-Berestein paola Amero School of Civil and Environmental Engineering and Construction Management The University of Texas at San AntonioSan AntonioTexasUSA Department of Cell Systems and Anatomy University of Texas Health Science CenterSan AntonioTexasUSA Department of Experimental Therapeutics The University of Texas MD Anderson Cancer CenterHoustonTexasUSA Edwards Aquifer Authority San AntonioTexasUSA

High-Grade Serous Ovarian Cancer(HGSC)is the most prevalent and lethal form of gynecologic malignancies[1],accounting for 70%-80%of ovarian cancer *** decades of research,the overall survival rate for HGSC has remained largely unchanged[2],and patients with advanced stages of the disease have only a 41%chance of surviving beyond five years[3].

关键词： cancer Cancer targeted

Enhanced entropy generation and heat transfer characteristics of magnetic nano-encapsulated phase change materials in latent heat thermal energy storage systems

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2024年第6期45卷 1051-1070页

作者： p.S.REDDY p.SREEDEVI Department of Mathematics Rajeev Gandhi Memorial College of Engineering and TechnologyNandyal 518501India

The objective of the current study is to investigate the importance of entropy generation and thermal radiation on the patterns of velocity,isentropic lines,and temperature contours within a thermal energy storage device filled with magnetic nanoencapsulated phase change materials(NEpCMs).The versatile finite element method(FEM)is implemented to numerically solve the governing *** effects of various parameters,including the viscosity parameter,ranging from 1 to 3,the thermal conductivity parameter,ranging from 1 to 3,the Rayleigh parameter,ranging from 102 to 3×10^(2),the radiation number,ranging from 0.1 to 0.5,the fusion temperature,ranging from 1.0 to 1.2,the volume fraction of NEpCMs,ranging from 2%to 6%,the Stefan number,ranging from 1 to 5,the magnetic number,ranging from 0.1 to 0.5,and the irreversibility parameter,ranging from 0.1 to 0.5,are examined in detail on the temperature contours,isentropic lines,heat capacity ratio,and velocity ***,the heat transfer rates at both the cold and hot walls are analyzed,and the findings are presented *** results indicate that the time taken by the NEpCMs to transition from solid to liquid is prolonged inside the chamber region as the fusion temperatureθf ***,the contours of the heat capacity ratio Cr decrease with the increase in the Stefan number Ste.

关键词： volume fraction of nano-encapsulated phase change material(NEpCM) radiation Stefan number heat capacity ratio entropy generation

维普期刊数据库

A Hybrid Optimization Approach of Single point Incremental Sheet Forming of AISI 316L Stainless Steel Using Grey Relation Analysis Coupled with principal Component Analysiss

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 2024年第1期39卷 160-166页

作者： A Visagan p Ganesh Department of production Technology Madras Institute of TechnologyChennai-600044India

We investigated the parametric optimization on incremental sheet forming of stainless steel using Grey Relational Analysis(GRA) coupled with principal Component Analysis(pCA). AISI 316L stainless steel sheets were used to develop double wall angle pyramid with aid of tungsten carbide tool. GRA coupled with pCA was used to plan the experiment conditions. Control factors such as Tool Diameter(TD), Step Depth(SD), Bottom Wall Angle(BWA), Feed Rate(FR) and Spindle Speed(SS) on Top Wall Angle(TWA) and Top Wall Angle Surface Roughness(TWASR) have been studied. Wall angle increases with increasing tool diameter due to large contact area between tool and workpiece. As the step depth, feed rate and spindle speed increase,TWASR decreases with increasing tool diameter. As the step depth increasing, the hydrostatic stress is raised causing severe cracks in the deformed surface. Hence it was concluded that the proposed hybrid method was suitable for optimizing the factors and response.

关键词： single point incremental forming AISI 316L taguchi grey relation analysis principal component analysis surface roughness scanning electron microscopy

维普期刊数据库

Cryogenic and conventional milling of AZ91 magnesium alloy

在线全文

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2024年第6期12卷 2503-2519页

作者： Vikas Marakini Srinivasa pai p Gururaj Bolar Bhaskara p Achar Department of Mechanical Engineering Nitte(Deemed to be University)NMAM Institute of Technology(NMAMIT)Nitte 574110India Department of Mechanical and Industrial Engineering Manipal Institute of TechnologyManipal Academy of Higher EducationManipal 576104India

Use of magnesium is the need of the hour due to its low density as well as its high strength-to-weight and stiffness-to-weight ratio *** study focuses on the effectiveness of liquid nitrogen(LN_(2))assisted cryogenic machining on the surface integrity(SI)characteristics of AZ91 magnesium *** milling using uncoated carbide inserts have been performed under liquid nitrogen(LN_(2))assisted cryogenic condition and compared with conventional(dry)*** are performed using machining parameters in terms of cutting speeds of 325,475,625 m/min,feed rates of 0.05,0.1,0.15 mm/teeth and depth of cuts of 0.5,1,1.5 mm *** significant surface integrity characteristics such as surface roughness,microhardness,microstructure,and residual stresses have been *** of SI characteristics with respect to milling parameters have been identified using statistical technique such as ANOVA and signal-to-noise(S/N)ratio ***,the multi criteria decision making(MCDM)techniques such as additive ratio assessment method(ARAS)and complex proportional assessment(COpRAS)have been utilized to identify the optimal conditions for milling AZ91 magnesium alloy under both dry and cryogenic *** of LN_(2)during machining,resulted in reduction in machining temperature by upto 29%with a temperature drop from 251.2℃under dry condition to 178.5℃in cryogenic *** showed the advantage of performing cryogenic milling in improving the surface integrity to a significant *** machining considerably minimized the roughness by upto 28%and maximised the microhardness by upto 23%,when compared to dry *** speed has caused significant impact on surface roughness(95.33%-dry,92.92%-cryogenic)and surface microhardness(80.33%-dry,82.15%-cryogenic).Due to the reduction in machining temperature,cryogenic condition resulted in compressive residual stresses(maximumσ║=-113 Mpa)on the alloy *** indicate no

关键词： Magnesium alloy Cryogenic machining Roughness Microhardness Microstructure Residual stress Multi criteria decision making

维普期刊数据库