Joint Channel Assignment and Opportunistic Routing for Maximizing Throughput in Cognitive Radio Networks

In this paper, we consider the joint opportunistic routing and channel assignment problem in multi-channel multi-radio (MCMR) cognitive radio networks (CRNs) for improving aggregate throughput of the secondary users. We first present the nonlinear programming optimization model for this joint problem, taking into account the feature of CRNs-channel uncertainty. Then considering the queue state of a node, we propose a new scheme to select proper forwarding candidates for opportunistic routing. Furthermore, a new algorithm for calculating the forwarding probability of any packet at a node is proposed, which is used to calculate how many packets a forwarder should send, so that the duplicate transmission can be reduced compared with MAC-independent opportunistic routing & encoding (MORE) [11]. Our numerical results show that the proposed scheme performs significantly better that traditional routing and opportunistic routing in which channel assignment strategy is employed.Comment: 5 pages, 4 figures, to appear in Proc. of IEEE GlobeCom 201

The Narcissistic Gaze in Pipilotti Rist’s Video Work Mutaflor (1996)

The project focuses on the research of the visual culture in the context of western societies from the 1970s to the 1990s and the art criticism on video art during that time. The final product of this project is an art criticism on the video artwork Mutaflor, made by Pipilotti Rist, an internationally renowned contemporary video and installation artist

On the existence and structures of almost axisymmetric solutions to 3-D Navier-Stokes equations

In this paper, we consider 3-D Navier-Stokes equations with almost axisymmetric initial data, which means that by writing $u_0 =u^r_0 e_r+u^\theta_0 e_\theta+u^z_0 e_z$ in the cylindrical coordinates, then $\partial_\theta u^r_0,\,\partial_\theta u^\theta_0$ and $\partial_\theta u^z_0$ are small in some sense (recall axisymmetric means these three quantities vanish). Then with additional smallness assumption on $u^\theta_0$, we prove the global existence of a unique strong solution $u$, and this solution keeps close to some axisymmetric vector field. We also establish some refined estimates for the integral average in $\theta$ variable for $u$. Moreover, as $u^r_0,\,u^\theta_0$ and $u^z_0$ here depend on $\theta$, it is natural to expand them into Fourier series in $\theta$ variable. And we shall consider one special form of $u_0$, with some small parameter $\varepsilon$ to measure its swirl part and oscillating part. We study the asymptotic expansion of the corresponding solution, and the influences between different profiles in the asymptotic expansion. In particular, we give some special symmetric structures that will persist for all time. These phenomena reflect some features of the nonlinear terms in Navier-Stokes equations

Code Completion by Modeling Flattened Abstract Syntax Trees as Graphs

Code completion has become an essential component of integrated development environments. Contemporary code completion methods rely on the abstract syntax tree (AST) to generate syntactically correct code. However, they cannot fully capture the sequential and repetitive patterns of writing code and the structural information of the AST. To alleviate these problems, we propose a new code completion approach named CCAG, which models the flattened sequence of a partial AST as an AST graph. CCAG uses our proposed AST Graph Attention Block to capture different dependencies in the AST graph for representation learning in code completion. The sub-tasks of code completion are optimized via multi-task learning in CCAG, and the task balance is automatically achieved using uncertainty without the need to tune task weights. The experimental results show that CCAG has superior performance than state-of-the-art approaches and it is able to provide intelligent code completion.Comment: Accepted in AAAI 2021. This version contains the appendix for the derivation of Eq. 1

A Study on English Translation of Poems and Lyrics by Mao Tse-tung from the Perspective of Metaphor

Mao Tse-tung is a great revolutionist, and his poems have always been praised as “A poem wins a country”. Metaphor is a process to understand and experience one thing through another thing, with its core to create undiscovered connections between ontology and metaphor, it is to combine two dissimilar things together. Poems and Lyrics written by Mao Tse-tung are rich in metaphors, this paper compares and studies four English translations of Mao Tse-tung’s poems(translated by Xu Yuanchong, Foreign Languages Press, Wang Huiming and Gu Zhengkun) from the perspective of metaphor at conceptual level, and discusses how translator deal with verbal metaphors and nominal metaphors. The results find that most of the translators choose to retain metaphors in the target language in order to accurately convey the information of the poems, which is suitable to translate metaphors in the poems

A Meshfree Method for Signorini Problems Using Boundary Integral Equations

This paper presents a meshfree method for the numerical solution of Signorini problems. In this method, a projection iterative algorithm is used to convert the boundary inequality constraints into a fixed point equation. Then, the boundary value problem is reformulated as boundary integral equations and the unknown boundary variables are interpolated by the point interpolation scheme. Thus, only a nodal data structure on the boundary of a domain is required, and boundary conditions can be implemented directly and easily. The convergence of this method is verified theoretically. Numerical examples involving groundwater flow and electropainting problems are also provided to illustrate the performance and usefulness of the method.</jats:p