检索结果-南通市图书馆

The Subgroups of Finite Metacyclic Groups

在线全文

学校读者我要写书评

暂无评论

Chinese Annals of Mathematics,Series B 2020年第2期41卷 241-266页

作者： xu yang School of Mathematical Sciences Fudan UniversityShanghai 200433China

In this paper, the author characterizes the subgroups of a finite metacyclic group K by building a one to one correspondence between certain 3-tuples(k, l, β) ∈ N3 and all the subgroups of K. The results are applied to compute some subgroups of K as well as to study the structure and the number of p-subgroups of K, where p is a fixed prime number. In addition, the author gets a factorization of K, and then studies the metacyclic p-groups, gives a different classification, and describes the characteristic subgroups of a given metacyclic p-group when p ≥ 3. A "reciprocity" relation on enumeration of subgroups of a metacyclic group is also given.

关键词： Metacyclic groups Subgroups Metacyclic p-groups Characteristic subgroups

New Insight into the Flexoelectricity in the View of Mechanics of Materials:Prismatic Beams Subjected to Bending

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 2024年第4期37卷 555-569页

作者： xu yang Lingling Chen Shengyou yang Department of Engineering Mechanics School of Civil EngineeringShandong UniversityJinan250061China

Flexoelectricity is a fascinating electromechanical phenomenon that occurs in non-homogeneously deformed dielectric *** piezoelectricity,the flexoelectric effect is highly dependent on both the material scale and the deformation *** several theoretical models have been proposed to explain the mechanism of flexoelectricity,these models can be rather complicated for those who are interested in studying the *** paper aims to simplify the understanding of flexoelectricity by focusing on the bending behavior of a prismatic dielectric beam from a mechanics of material *** avoid using complicated mathematical formulations based on continuum mechanics,including advanced tensor algebra and calculus of *** formulation clearly explains how inhomogeneous deformations and material size affect the electromechanical coupling,changing the effective bending stiffness,deflection,and rotation angles of a bending *** hope this paper can help undergraduate students and researchers,who are unfamiliar with the electromechanical coupling in flexoelectricity,to develop an understanding of this phenomenon and encourage further research in this area.

关键词： bending formulation dielectric

Graphene photonic crystal fiber with large modulation depth

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 Chemistry 2020年第1期63卷 5-6页

作者： yang xu Chao Gao College of Information Science and Electronic Engineering Zhejiang UniversityHangzhou 310027China Department of Polymer Science and Engineering Zhejiang UniversityHangzhou 310027China

Optical fiber communication has become an important pillar of information technology in the 21 st century due to its advantages of large communication capacity,small signal in terference and good *** the increasing demand for larger capacity,multi-function and security of optical network,the advantages of photonic crystal fiber(PCF)in optical transmission and regulation are gradually emerging[1,2].In particular,the combination of PCF with some functional materials has greatly broadened the application fields of optical ***,as a functional film with high mobility,broadband absorption and adjustable electrical properties,is a promising material for the next generation of photonic and photoelectronic applications[3-5].

关键词： fiber communication network

Bio-inspired motion planning for reaching movement of a manipulator based on intrinsic tau jerk guidance

在线全文

学校读者我要写书评

暂无评论

Advances in Manufacturing 2019年第3期7卷 315-325页

作者： Zhen Zhang xu yang School of Mechatronic Engineering and Automation Shanghai UniversityShanghai 200444People's Republic of China

This study proposed a bio-inspired motion planning approach for the reaching movement of a robot manipulator based on a novel intrinsic tau jerk guidance strategy,which was established by some cognitive science researchers when they studied motion patterns through *** accordance with the rules of human reaching movement,the intrinsic tau jerk guidance strategy ensures continuity of the acceleration;further,it also ensures that its value is zero at the start and end of the *** approach has been implemented on a three-degrees-offreedom 3R planar *** results show that,within a defined time,both the position gap and attitude gap can be reposefully closed,and the curves of joint velocity,acceleration,and driving torque are continuous and *** to the dynamic analysis,the proposed approach tends to consume less *** bioinspired method has the potential to be applied in particular scenarios in the future,such as a mobile robot with a manipulator exploring an unknown environment.

关键词： Bio-inspired Motion planning Manipulator Reaching movement Intrinsic tau jerk guidance

A multivariate partial least squares approach to joint association analysis for multiple correlated traits

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

The Crop Journal 2016年第1期4卷 21-29页

作者： yang xu Wenming Hu Zefeng yang Chenwu xu Jiangsu Key Laboratory of Crop Genetics and Physiology Co-Innovation Center for Modern Production Technology of Grain CropsKey Laboratory of Plant Functional Genomics of the Ministry of Education Yangzhou University

Many complex traits are highly correlated rather than independent. By taking the correlation structure of multiple traits into account, joint association analyses can achieve both higher statistical power and more accurate estimation. To develop a statistical approach to joint association analysis that includes allele detection and genetic effect estimation, we combined multivariate partial least squares regression with variable selection strategies and selected the optimal model using the Bayesian Information Criterion(BIC). We then performed extensive simulations under varying heritabilities and sample sizes to compare the performance achieved using our method with those obtained by single-trait multilocus methods. Joint association analysis has measurable advantages over single-trait methods, as it exhibits superior gene detection power, especially for pleiotropic genes. Sample size, heritability,polymorphic information content(PIC), and magnitude of gene effects influence the statistical power, accuracy and precision of effect estimation by the joint association analysis.

关键词： Association analysis Multiple correlated traits Supersaturated model Multilocus Multivariate partial least squares

Genetic mapping of quantitative trait loci in crops

在线全文

学校读者我要写书评

暂无评论

The Crop Journal 2017年第2期5卷 175-184页

作者： yang xu Pengcheng Li Zefeng yang Chenwu xu Jiangsu Provincial Key Laboratory of Crop Genetics and Physiology/Co-Innovation Center for Modern Production Technology of Grain Crops Key Laboratory of Plant Functional Genomics of Ministry of Education Yangzhou University Yangzhou 225009 China

Dissecting the genetic architecture of complex traits is an ongoing challenge for *** complementary approaches for genetic mapping,linkage mapping and association mapping have led to successful dissection of complex traits in many crop *** of these methods detect quantitative trait loci(QTL) by identifying marker–trait associations,and the only fundamental difference between them is that between mapping populations,which directly determine mapping resolution and *** on this difference,we first summarize in this review the advances and limitations of family-based mapping and natural population-based mapping instead of linkage mapping and association *** then describe statistical methods used for improving detection power and computational speed and outline emerging areas such as large-scale meta-analysis for genetic mapping in *** the era of next-generation sequencing,there has arisen an urgent need for proper population design,advanced statistical strategies,and precision phenotyping to fully exploit high-throughput genotyping.

关键词： Family-based mapping Natural population-based mapping Mixed linear model MAGIC population Meta-analysis Genotyping by sequencing

Multi-UAV cooperative maneuver decision-making for pursuitevasion using improved MADRL

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2024年第5期35卷 187-197页

作者： Delin Luo Zihao Fan Ziyi yang yang xu School of Aerospace Engineering Xiamen UniversityXiamen 361102China School of Civil Aviation Northwestern Polytechnical UniversityXi'an 710072China

Aiming at the problem of multi-UAV pursuit-evasion confrontation, a UAV cooperative maneuver method based on an improved multi-agent deep reinforcement learning(MADRL) is proposed. In this method, an improved Comm Net network based on a communication mechanism is introduced into a deep reinforcement learning algorithm to solve the multi-agent problem. A layer of gated recurrent unit(GRU) is added to the actor-network structure to remember historical environmental states. Subsequently,another GRU is designed as a communication channel in the Comm Net core network layer to refine communication information between UAVs. Finally, the simulation results of the algorithm in two sets of scenarios are given, and the results show that the method has good effectiveness and applicability.

关键词： Reinforcement learning UAV Maneuver decision GRU Cooperative control

STRONG CONVERGENCE OF JUMP-ADAPTED IMPLICIT MILSTEIN METHOD FOR A CLASS OF NONLINEAR JUMP-DIFFUSION PROBLEMS

在线全文

学校读者我要写书评

暂无评论

Journal of Computational Mathematics 2024年第1期42卷 248-270页

作者： xu yang Weidong Zhao School of Mathematics China University of Mining and TechnologyXuzhou 221116China School of Mathematics Shandong UniversityJinan 250100China

In this paper,we study the strong convergence of a jump-adapted implicit Milstein method for a class of jump-diffusion stochastic differential equations with non-globally Lipschitz drift *** with the regular methods,the jump-adapted methods can significantly reduce the complexity of higher order methods,which makes them easily implementable for scenario ***,due to the fact that jump-adapted time discretization is path dependent and the stepsize is not uniform,this makes the numerical analysis of jump-adapted methods much more involved,especially in the non-globally Lipschitz *** provide a rigorous strong convergence analysis of the considered jump-adapted implicit Milstein method by developing some novel analysis techniques and optimal rate with order one is also successfully *** experiments are carried out to verify the theoretical findings.

关键词： Jump-diffusion Jump-adapted implicit Milstein method Poisson jumps Strong convergence rate Non-Lipschitz coefficients

A data complementary method for thunderstorm point charge localization based on atmospheric electric field apparatus array group

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Digital Communications and Networks 2021年第2期7卷 170-177页

作者： xu yang Hongyan Xing Collaborative Innovation Center for Meteorological Disaster Prediction and Evaluation Nanjing University of Information Science and TechnologyNanjing210044China Jiangsu Key Laboratory of Meteorological Detection and Information Processing Nanjing University of Information Science and TechnologyNanjing210044China

Data loss or distortion causes adverse effects on the accuracy and stability of the thunderstorm point charge *** solve this problem,we propose a data complementary method based on the atmospheric electric field apparatus array *** electric field component measurement model of the atmospheric electric field apparatus is established,and the orientation parameters of the thunderstorm point charge are *** on the mirror method,the thunderstorm point charge coordinates are obtained by using the potential distribution *** test the validity of the basic algorithm,the electric field component measurement error and the localization accuracy are *** the azimuth angle and the elevation angle,the localization parameters also include the distance from the apparatus to the thunderstorm *** on a primary electric field apparatus,we establish the array group of *** on this,the data measured by each apparatus is complementarily processed to regain the thunderstorm point charge *** results show that,compared with the radar map data,this method can accurately reflect the location of the thunderstorm point charge,and has a better localization ***,several observation results during thunderstorm weather have been presented.

关键词： Atmospheric electric field apparatus Array Thunderstorm point charge Data complementary