检索结果-南通市图书馆

Equivariant Chern Classes of Orientable Toric Origami Manifolds

在线全文

学校读者我要写书评

暂无评论

Chinese Annals of mathematics,Series B 2024年第2期45卷 221-234页

作者： Yueshan XIONG Haozhi ZENG school of mathematics and StatisticsHuazhong University of science and Technology Wuhan 430074China

A toric origami manifold,introduced by Cannas da Silva,Guillemin and Pires,is a generalization of a toric symplectic *** a toric symplectic manifold,its equivariant Chern classes can be described in terms of the corresponding Delzant polytope and the stabilization of its tangent bundle splits as a direct sum of complex line *** in general a toric origami manifold is not simply connected,so the algebraic topology of a toric origami manifold is more difficult than a toric symplectic *** this paper they give an explicit formula of the equivariant Chern classes of an oriented toric origami manifold in terms of the corresponding origami ***,they prove the stabilization of the tangent bundle of an oriented toric origami manifold also splits as a direct sum of complex line bundles.

关键词： Equivariant Chern classes Toric origami manifolds Unitary structures Spin structures

GENERALIZED FORELLI-RUDIN TYPE OPERATORS BETWEEN SEVERAL FUNCTION SPACES ON THE UNIT BALL OF C^(N)

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Scientia 2024年第4期44卷 1301-1326页

作者： Xuejun ZHANG Yuting GUO Hongxin CHEN Pengcheng TANG College of mathematics and Statistics Hunan Normal University.Changsha 410081China school of mathematics Hunan UniversityChangsha 410082China school of mathematics and Computational science Hunan University of Science and TechnologyXiangtan 411201China

In this paper,we investigate sufficient and necessary conditions such that generalized Forelli-Rudin type operators T_(λ,τ,k),S_(λ,τ,k),Q_(λ,τ,k)and R_(λ,τ,k)are bounded between Lebesgue type *** order to prov... 详细信息

关键词： Forelli-Rudin type operator L^(p,q,s,k)(B_(n))space boundedness unit ball

A SINGULAR DIRICHLET PROBLEM FOR THE MONGE-AMPÈRE TYPE EQUATION

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Scientia 2024年第5期44卷 1965-1983页

作者： Zhijun ZHANG Bo ZHANG school of mathematics and Information science Yantai UniversityYantai264005China

We consider the singular Dirichlet problem for the Monge-Ampère type equation{\rm det}\D^2 u=b(x)g(-u)(1+|\nabla u|^2)^{q/2},\u<0,\x\in\Omega,\u|_{\partial\Omega}=0,whereΩis a strictly convex and bounded smooth domain inℝn,q∈[0,n+1),g∈C∞(0,∞)is positive and strictly decreasing in(0,∞)with\lim\limits_{s\rightarrow 0^+}g(s)=\infty,and b∈C∞(Ω)is positive inΩ.We obtain the existence,nonexistence and global asymptotic behavior of the convex solution to such a problem for more general b and *** approach is based on the Karamata regular variation theory and the construction of suitable sub-and super-solutions.

关键词： Monge-Ampère equation a singular boundary value problem the unique convex solution global asymptotic behavior

The joint Laplace transforms for killed diffusion occupation times

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

Applied mathematics(A Journal of Chinese Universities) 2024年第3期39卷 398-415页

作者： LI Ying-qiu CHEN Ye school of mathematics and Statistics Changsha University of Science and TechnologyChangsha 410114China College of mathematics and Computational science Hunan University of Arts and ScienceChangde 415000China

The approach of Li and Zhou(2014)is adopted to find the Laplace transform of occupation time over interval(0,a)and joint occupation times over semi-infinite intervals(-∞,a)and(b,∞)for a time-homogeneous diffusion pr... 详细信息

关键词： time-homogeneous diffusion process occupation time joint occupation time Laplace transform Brownian motion with drift

Flexible,efficient,and accurate tests for epidemics

在线全文

学校读者我要写书评

暂无评论

science China mathematics 2024年第8期67卷 1881-1898页

作者： Linjiajie Fang Bing-Yi Jing Shen Ling Qiyue Wang Qing Yang data science and Analytics Thrust The Hong Kong University of Science and TechnologyHong KongChina Department of Statistics and data science Southern University of Science and TechnologyShenzhen 518055China Department of mathematics and Statistics Dalhousie UniversityHalifaxNS B 3H 4R 2Canada Department of mathematics The Hong Kong University of Science and TechnologyHong KongChina

Group testing involves discovering a small subset of distinguished subjects from a large population while efficiently reducing the total number of *** has been widely used for industrial testing,information technology,and biology,especially epidemic ***,in reality,are noisy for the presence of false *** tests are accurate but time-consuming,while others are cheaper but less *** which test to use is constrained by various considerations,such as availability,cost,accuracy,and *** this paper,we propose flexible,efficient,and accurate tests(FEATs).FEATs are based on group testing with simple but careful designs by incorporating ideas such as close contact cliques and repeated *** could dramatically improve the efficiency or accuracy of existing *** example,for accurate but slow tests,the FEAT can improve efficiency multiple times without compromising *** the other hand,for fast but inaccurate tests,the FEAT can sharply reduce the false-negative rate(FNR)and significantly increase *** justifications are *** point out some scenarios where the FEAT can be effectively employed.

关键词： epidemiology control blood testing testing efficiency testing accuracy

Semisymmetric Graphs of Order 2p^(3)with Valency p^(2)

在线全文

学校读者我要写书评

暂无评论

Algebra Colloquium 2024年第2期31卷 199-208页

作者： Li Wang Songtao Guo Genghua Fan school of mathematics and Information science Henan Polytechnic University JiaozuoHenan 454000China school of mathematics and Statistics Henan University of Science and Technology LuoyangHenan 471023China 不详

A simple undirected regular graph is said to be semisymmetric if it is edge-transitive but not *** a semisymmetric graphΓof order 2p^(3),p a prime,it is well known thatΓis bipartite with two biparts having equal *** complete classification of such graphs has been given for the full automorphism group Aut(Γ)acting unfaithfully on at least one bipart ofΓ,which shows that there is only one infinite family of such graphs with valency p^(2).The graphs of this kind have been determined when Aut(Γ)acts faithfully and primitively on at least one bipart ofΓ,and thus there is only one remaining case for classifying such graphs of valency p^(2),Aut(Γ)acting faithfully and imprimitively on both biparts ofΓ,which is dealt with in this *** a result,there is only one infinite family of semisymmetric graphs of order 2p^(3)with valency p^(2).

关键词： semisymmetric graph semitransitive graph bi-coset graph

Computer vision tasks for intelligent aerospace perception: An overview

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

science China(Technological sciences) 2024年第9期67卷 2727-2748页

作者： CHEN HuiLin SUN QiYu LI FangFei TANG Yang school of Information science and Engineering East China University of Science and TechnologyShanghai 200237China school of mathematics East China University of Science and TechnologyShanghai 200237China

Computer vision tasks are crucial for aerospace missions as they help spacecraft to understand and interpret the space environment,such as estimating position and orientation, reconstructing 3D models, and recognizing objects, which have been extensively studied to successfully carry out the missions. However, traditional methods like Kalman filtering, structure from motion, and multi-view stereo are not robust enough to handle harsh conditions, leading to unreliable results. In recent years, deep learning(DL)-based perception technologies have shown great potential and outperformed traditional methods, especially in terms of their robustness to changing environments. To further advance DL-based aerospace perception, various frameworks, datasets,and strategies have been proposed, indicating significant potential for future applications. In this survey, we aim to explore the promising techniques used in perception tasks and emphasize the importance of DL-based aerospace perception. We begin by providing an overview of aerospace perception, including classical space programs developed in recent years, commonly used sensors, and traditional perception methods. Subsequently, we delve into three fundamental perception tasks in aerospace missions: pose estimation, 3D reconstruction, and recognition, as they are basic and crucial for subsequent decision-making and control. Finally, we discuss the limitations and possibilities in current research and provide an outlook on future developments,including the challenges of working with limited datasets, the need for improved algorithms, and the potential benefits of multisource information fusion.

关键词： deep learning perception aerospace missions pose estimation 3D reconstruction recognition

One-step hydrothermal synthesis of Cit-NaYbF_(4):Er^(3+)nanocrystals with enhanced red upconversion emission for in vivo fluorescence molecular tomography

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2024年第1期42卷 36-45,I0002页

作者： Xiaoli Luo Qichen Chen Hongbo Guo Heng Zhang Xiaowei He Wu Zhao school of mathematics and Computer science Ningxia Normal UniversityGuyuan756099China school of Information science and Technology Northwest UniversityXi'an710127China

Fluorescence imaging techniques represent essential tools in in vitro,preclinical,and clinical *** this study,an improved one-step hydrothermal method to synthesize citric acid(CA)modifiedα-NaYbF_(4):2%Er^(3+)nanocrystals was *** introduction of various doping ions into NaYbF_(4):2%Er^(3+)and the different valence states of the same ions affect both the crystal size and upconversion luminesce *** fore,we investigated the upconversion luminesce nce enha ncement of NaYbF_(4):2%Er^(3+)by ion doping and find that the upconversion luminescence intensity of the upconversion nanoparticles(UCNPs)co-doped with 5 mol%Fe^(2+)ions shows the greatest enhancement,especially for red emission at654 ***,HeLa cells incubated with UCNPs allow for imaging with strong red upconversion emission detectio *** laser scanning microscope(CLSM)fluorescent images of HeLa cells indicate that NaYbF_(4):2%Er/5%Fe^(2+)leads to a clear outline and improves visualization of the cell *** addition,the CA coated NaYbF_(4):2%Er^(3+)/5%Fe^(2+)nanoparticles and NaYbF_(4):2%Er^(3+)/5%Fe^(2+)show low cytotoxicity in HeLa *** imaging reveals the efficiency of these UCNPs to analyze the lungs,liver,and ***,these results indicate that the Cit-NaYbF_(4):2%Er^(3+)/5%Fe^(2+)UCNPs are efficient nanoprobes for fluorescence molecular to mography.

关键词： Hydrothermal method Fe^(2+)ion doping Tuning size Nanoprobes Fluorescence imaging Rare earths

Understanding and improving fairness in cognitive diagnosis

在线全文

学校读者我要写书评

暂无评论

science China(Information sciences) 2024年第5期67卷 99-114页

作者： Zheng ZHANG Le WU Qi LIU Jiayu LIU Zhenya HUANG Yu YIN Yan ZHUANG Weibo GAO Enhong CHEN Anhui Province Key Laboratory of Big data Analysis and Application School of Computer Science and Technology& School of Data Science University of Science and Technology of China State Key Laboratory of Cognitive Intelligence school of Computer science and Information Engineering Hefei University of Technology

Intelligent education is a significant application of artificial intelligence. One of the key research topics in intelligence education is cognitive diagnosis, which aims to gauge the level of proficiency among students on specific knowledge concepts(e.g., Geometry). To the best of our knowledge, most of the existing cognitive models primarily focus on improving diagnostic accuracy while rarely considering fairness issues; for instance, the diagnosis of students may be affected by various sensitive attributes(e.g., region). In this paper,we aim to explore fairness in cognitive diagnosis and answer two questions:(1) Are the results of existing cognitive diagnosis models affected by sensitive attributes?(2) If yes, how can we mitigate the impact of sensitive attributes to ensure fair diagnosis results? To this end, we first empirically reveal that several wellknown cognitive diagnosis methods usually lead to unfair performances, and the trend of unfairness varies among different cognitive diagnosis models. Then, we make a theoretical analysis to explain the reasons behind this phenomenon. To resolve the unfairness problem in existing cognitive diagnosis models, we propose a general fairness-aware cognitive diagnosis framework, FairCD. Our fundamental principle involves eliminating the effect of sensitive attributes on student proficiency. To achieve this, we divide student proficiency in existing cognitive diagnosis models into two components: bias proficiency and fair *** design two orthogonal tasks for each of them to ensure that fairness in proficiency remains independent of sensitive attributes and take it as the final diagnosed result. Extensive experiments on the Program for International Student Assessment(PISA) dataset clearly show the effectiveness of our framework.

关键词： fairness intelligent education cognitive diagnosis psychometrics adversarial learning