检索结果-南通市图书馆

Joint Optimization of Resource Allocation and Trajectory Based on User Trajectory for UAV-Assisted Backscatter Communication System

在线全文

学校读者我要写书评

暂无评论

China Communications 2024年第2期21卷 197-209页

作者： Peizhong xie Junjie Jiang Ting Li yin Lu School of Communication and Information Engineering Nanjing University of Posts and TelecommunicationsNanjing 210003China Key Lab of Broadband Wireless Communication and Sensor Network Technology(Nanjing University of Posts and Telecommunications) Ministry of EducationNanjing 210003China

The Backscatter communication has gained widespread attention from academia and industry in recent years. In this paper, A method of resource allocation and trajectory optimization is proposed for UAV-assisted backscatter communication based on user trajectory. This paper will establish an optimization problem of jointly optimizing the UAV trajectories, UAV transmission power and BD scheduling based on the large-scale channel state signals estimated in advance of the known user trajectories, taking into account the constraints of BD data and working energy consumption, to maximize the energy efficiency of the system. The problem is a non-convex optimization problem in fractional form, and there is nonlinear coupling between optimization *** iterative algorithm is proposed based on Dinkelbach algorithm, block coordinate descent method and continuous convex optimization technology. First, the objective function is converted into a non-fractional programming problem based on Dinkelbach method,and then the block coordinate descent method is used to decompose the original complex problem into three independent sub-problems. Finally, the successive convex approximation method is used to solve the trajectory optimization sub-problem. The simulation results show that the proposed scheme and algorithm have obvious energy efficiency gains compared with the comparison scheme.

关键词： energy efficiency joint optimization UAV-assisted backscatter communication user trajectory

Local Hamilton type Gradient Estimates and Harnack Inequalities for Nonlinear Parabolic Equations on Riemannian Manifolds

在线全文

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2024年第2期40卷 539-546页

作者： Wen WANG Da-peng xie hui ZHOU School of Mathematics and Statistics Hefei Normal UniversityHefei 230601China

In this paper,we prove a local Hamilton type gradient estimate for positive solution of the nonlinear parabolic equation ut(x,t)=Δu(x,t)+au(x,t) ln u(x,t)+bu^(α)(x,t),on M×(-∞,∞) with α∈R,where a and b are *** ... 详细信息

关键词： nonlinear parabolic equation gradient estimate Harnack inequality

Existence of Positive Solutions to a Fractional-Kirchhoff System

在线全文

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2024年第1期40卷 225-240页

作者： Peng-fei Li Jun-hui xie Dan Mu School of Mathematics and Statistics Hubei Minzu UniversityEnshi445000China

LetΩbe a bounded smooth domain in RN(N≥3).Assuming that 00 are constants,we consider the existence results for positive solutions of a class of fractional elliptic system below,{(a+b[u]^(2)_(s))(-Δ)^(s)u=vp+h_(1)(x,u,v,▽u,▽v),x∈Ω,(-Δ)^(s)v=u^(q)+h_(2)(x,u,▽,▽u,▽v),x∈Q,u,v>0,x∈Ω,u=v=0,x∈RN\Ω.Under some assumptions of hi(x,u,v,▽u,▽v)(i=1,2),we get a priori bounds of the positive solutions to the problem(1.1)by the blow-up methods and rescaling *** on these estimates and degree theory,we establish the existence of positive solutions to problem(1.1).

关键词： fractional-Kirchhoff system a priori bounds degree theory positive solution

Numerical Simulation of Droplet Generation in Coaxial Microchannels

在线全文

学校读者我要写书评

暂无评论

Fluid Dynamics & Materials Processing 2024年第3期20卷 487-504页

作者： Zongjun yin Rong Su hui Xu School of Mechanical Engineering Anhui Institute of Information TechnologyWuhu241100China

In this study,numerical simulations of the pinching-off phenomena displayed by the dispersed phase in a continuous phase have been conducted using COMSOL Multiphysics(level-set method).Four flow patterns,namely“drop flow”,“jet flow”,“squeeze flow”,and“co-flow”,have been obtained for different flow velocity ratios,channel diameter ratios,density ratios,viscosity ratios,and surface *** flow pattern map of two-phase flow in coaxial microchannels has been obtained accordingly,and the associated droplet generation process has been critically discussed considering the related frequency,diameter,and pinch-off *** particular,it is shown that the larger the flow velocity ratio,the smaller the diameter of generated droplets and the shorter the pinch-off *** pinch-off length of a droplet is influenced by the channel diameter ratio and density *** changes in viscosity ratio have a negligible influence on the droplet generation pinching *** an increase in surface tension,the frequency of generation and pinch-off length of droplets decrease,but for small surface tension the generation diameter of droplet increases.

关键词： Droplet generation characteristics coaxial microchannels flow patterns pinch-off length

Effects of Aromatherapy on Physical and Mental Health of Cancer Patients Undergoing Radiotherapy and/or Chemotherapy: A Meta-Analysis

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Integrative Medicine 2024年第5期30卷 449-457页

作者： xie Shuang-ran MA Liang XU Xin-yu ZHOU Shu xie hui-miao xie Chang-sheng The First Clinical Medical College Zhejiang Chinese Medical UniversityHangzhou 310053China Department of Medical Oncology Hangzhou Traditional Chinese Medicine Hospital Affiliated to Zhejiang Chinese Medical UniversityHangzhou 310007China Department of Dermatology the Third Xiangya HospitalCentral South UniversityChangsha 410013China Department of Famous Chinese Medicine Clinic the Second Affiliated Hospital of Zhejiang Chinese Medical UniversityHangzhou 310005China Department of Medical Oncology the First Affiliated Hospital of Zhejiang Chinese Medical UniversityHangzhou 310006China

Backgroup:Currently,aromatherapy is being increasingly utilized in clinical practice,particularly in managing the side effects associated with radiotherapy and ***,it remains to be established whether aromatherapy can effectively alleviate these ***:To investigate the effects of aromatherapy on the physical and mental health of patients with cancer undergoing radiotherapy and ***:Seven databases were researched from inception until September 29,2023,including PubMed,Scopus,and Web of Science,Chinese National Knowledge Infrastructure,Wanfang database,China Biology Medicine disc and VIP Chinese Medical Journal *** Manager version 5.3 was utilized for data *** Cochrane Risk of Bias tool RoB2 was employed to evaluate the quality of the literature included in the *** quality rating was assessed using the Grading of Recommendations Assessment,Development,and Evaluation(GRADE) approach through the GRADEpro GDT online ***:Nineteen studies involving 1,541 patients were *** can alleviate nausea [relative risk(RR)=0.64,95% confidence interval(CI):0.53 to 0.78,P<0.05,I^(2)=46%;standardized mean difference(SMD)=-0.86,95% CI:-1.21 to-0.51,P<0.05,I^(2)=64%] and vomiting(RR=0.54,95% CI:0.42 to 0.69,P<0.05,I^(2)=35%;SMD=-1.28,95% CI:-1.52 to-1.03,P<0.05,I^(2)=92%),improve sleep disorders [mean difference(MD)=-3.39,95% CI:-3.95 to-2.84,P<0.05,I^(2)=0%],relieve pain(SMD=-1.58,95% CI:-1.96 to-1.21,P<0.05,I^(2)=0%),mitigate fatigue(SMD=-1.28,95% CI:-2.44 to-0.11,P<0.05,I^(2)=93%) and enhance quality of life(SMD=0.50,95% CI:0.22 to 0.79,P<0.05,I^(2)=0%) in cancer patients after radiotherapy and chemotherapy,but it may not have a significant effect on *** risk of bias was high in the included studies using the Cochrane Risk of Bias tool RoB2,and no studies were considered to be of high grade according to the GRADE ***:Aromatherapy is an efficacious,safe a

关键词： aromatherapy cancer chemoradiotherapy physical psychological

Deep learning to estimate ocean subsurface salinity structure in the Indian Ocean using satellite observations

在线全文

学校读者我要写书评

暂无评论

Journal of Oceanology and Limnology 2024年第2期42卷 377-389页

作者： Jifeng QI Guimin SUN Bowen xie Delei LI Baoshu yin CAS Key Laboratory of Ocean Circulation and Waves Institute of OceanologyChinese Academy of SciencesQingdao 266071China University of Chinese Academy of Sciences Beijing 100049China School of Mathematics and Physics Qingdao University of Science and TechnologyQingdao 266061China CAS Engineering Laboratory for Marine Ranching Institute of OceanologyChinese Academy of SciencesQingdao 266071China

Accurately estimating the ocean subsurface salinity structure(OSSS)is crucial for understanding ocean dynamics and predicting climate *** present a convolutional neural network(CNN)model to estimate the OSSS in the Indian Ocean using satellite data and Argo *** evaluated the performance of the CNN model in terms of its vertical and spatial distribution,as well as seasonal variation of OSSS *** demonstrate that the CNN model accurately estimates the most significant salinity features in the Indian Ocean using sea surface data with no significant differences from Argo-derived ***,the estimation accuracy of the CNN model varies with depth,with the most challenging depth being approximately 70 m,corresponding to the halocline *** of the CNN model’s accuracy in estimating OSSS in the Indian Ocean are also conducted by comparing Argo observations and CNN model estimations along two selected sections and four selected *** results show that the CNN model effectively captures the seasonal variability of salinity,demonstrating its high performance in salinity estimation using sea surface *** analysis reveals that sea surface salinity has the strongest correlation with OSSS in shallow layers,while sea surface height anomaly plays a more significant role in deeper *** preliminary results provide valuable insights into the feasibility of estimating OSSS using satellite observations and have implications for studying upper ocean dynamics using machine learning techniques.

关键词： machine learning convolutional neural network(CNN) ocean subsurface salinity structure(OSSS) Indian Ocean satellite observations

Insight into the Role and Evidence of Oxygen Vacancies in Porous Single-Crystalline Oxide to Enhance Catalytic Activity and Durability

在线全文

学校读者我要写书评

暂无评论

Research 2024年第2期2023卷 675-683页

作者： Lingting Ye Jiaming Ma Jie Zhang Wen yin Yuanguang Xia Kui xie Key Laboratory of Optoelectronic Materials Chemistry and Physics Fujan Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhouFujian 350002China Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China FuzhouFujian 350108China Advanced Energy Science and Technology Guangdong Laboratory 29 Sanxin North RoadHuizhouGuangdong 116023China Spallation Neutron Source Science Center DongguanGuangdong 523803China

Introducing and stabilizing oxygen vacancies in oxide catalysts is considered to be a promising strategy for improving catalytic activity and ***,we quantitatively create oxygen vacancies in the lattice of porous single-crystallineβ-Ga_(2)O_(3)monoliths by reduction treatments and stabilize them through the long-range ordering of crystal lattice to enhance catalytic activity and *** combination analysis of time-of-flight neutron powder diffraction and extended x-ray absorption fine structure discloses that the preferential generation of oxygen vacancy tends to occur at the site of tetrahedral coordination oxygen ions(O_(Ⅲ)sites),which contributes to the formation of unsaturated Ga-O coordination in the monoclinic *** oxygen vacancies are randomly distributed in lattice even though some of them are present in the form of domain defect in the PSC Ga_(2)O_(3)monoliths after the reduction *** number of oxygen vacancies in the reduced monoliths gives 2.32×10^(13),2.87×10^(13),and 3.45×10^(13)mg^(-1)for the Ga_(2)O_(2.952),Ga_(2)O_(2.895),and Ga_(2)O_(2.880),*** therefore demonstrate the exceptionally high C_(2)H_(4)selectivity of~100%at the C_(2)H_(6)conversion of~37%for nonoxidative dehydrogenation of C_(2)H_(6)to C_(2)H_(4).We further demonstrate the excellent durability even at 620℃for 240 h of continuous operation.

关键词： durability coordination Oxygen

Tuning heterogeneous microstructures to enhance mechanical properties of nano-TiN particle reinforced Haynes 230 composites by laser powder bed fusion

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Rare Metals 2024年第9期43卷 4548-4565页

作者： Wen-Jie Liu hui Li Qian-Xing yin He-Jun Du School of Power and Mechanical Engineering Wuhan UniversityWuhan 430072China The Institute of Technological Sciences Wuhan UniversityWuhan 430072China School of Mechanical&Aerospace Engineering Nanyang Technological UniversitySingapore 639798Singapore

Laser powder bed fusion(LPBF)is considered to be one of the most promising additive manufacturing technologies for producing components with geometries and high geometrical precision that are unattainable by traditional *** superalloy exhibits exceptional mechanical and high-temperature performances,rendering it a prime candidate for advanced aero-engine *** the high demand for LPBF-manufactured superalloys,the superalloy is one of the materials manufactured difficultly by LPBF due to their large laser absorptivity fluctuation,poor molten pool stability and sharp temperature ***,superalloys are characterized by severe pores,undesirable coarse columnar grains and poor mechanical *** this work,the effect of nano-TiN particles on defects,molten pool characteristics and microstructure and performance of the composites were *** 4.5 wt%TiN/Haynes230 samples exhibited exceptional nanohardness and elastic modulus with maximum values reaching 5.53 GPa and 240.03 GPa,*** superior mechanical properties were attributed to the combined effects of spatter and gas pore inhibition,grain refinement and duplex nanophases ***,the stability of molten pool was enhanced,and spatter was effectively suppressed by adding nano-TiN particles,while grain refinement and columnar to equiaxed transitions were ***,the matrix exhibited a high dislocation density due to a significant hindrance of dislocation movement caused by massive nano-phases(e.g.,TiN and M_(23)C_(6)),resulting in the formation of extensive dislocation tangles and *** work offers novel insights into the role of nanoparticles reinforced superalloy composites by LPBF.

关键词： Composites Laser powder bed fusion Molten pool characteristics Microstructure Mechanical properties

Privacy-Preserving Federated Deep Learning Diagnostic Method for Multi-Stage Diseases

在线全文

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2024年第6期139卷 3085-3099页

作者： Jinbo Yang Hai Huang Lailai yin Jiaxing Qu Wanjuan xie School of Computer Science and Technology Harbin University of Science and TechnologyHarbin150080China Shanghai Futures Information Technology Co. Ltd.Shanghai201201China Heilongjiang Province Cyberspace Research Center Harbin150001China Information Network Engineering and Research Center South China University of TechnologyGuangzhou510641China

Diagnosing multi-stage diseases typically requires doctors to consider multiple data sources,including clinical symptoms,physical signs,biochemical test results,imaging findings,pathological examination data,and even genetic *** applying machine learning modeling to predict and diagnose multi-stage diseases,several challenges need to be ***,the model needs to handle multimodal data,as the data used by doctors for diagnosis includes image data,natural language data,and structured ***,privacy of patients’data needs to be protected,as these data contain the most sensitive and private ***,considering the practicality of the model,the computational requirements should not be too *** address these challenges,this paper proposes a privacy-preserving federated deep learning diagnostic method for multi-stage *** method improves the forward and backward propagation processes of deep neural network modeling algorithms and introduces a homomorphic encryption step to design a federated modeling algorithm without the need for an *** also utilizes dedicated integrated circuits to implement the hardware Paillier algorithm,providing accelerated support for homomorphic encryption in ***,this paper designs and conducts experiments to evaluate the proposed *** experimental results show that in privacy-preserving federated deep learning diagnostic modeling,the method in this paper achieves the same modeling performance as ordinary modeling without privacy protection,and has higher modeling speed compared to similar algorithms.

关键词： Vertical federation homomorphic encryption deep neural network intelligent diagnosis machine learning and big data