高清晰度电视信号用外插内插预测编码方法

本文介绍了一种高清晰度电视(HDTV)信号的数字传输用高效编码方法。由于HDTV信号的带宽宽,所以存在两个主要问题:一是HDTV信号的随机噪声比传统电视信号的大,因而导致编码的效率下降;二是需要很高的取样频率。这样,就限制了编码算法的硬件实现。因此,本文提出两种技术来解决这些问题:第一是时空自适应滤波器,用它可降低随机噪声并改善编码效率;第二是具有自适应内场/帧间预测的外插和内插编码算法,这种算法消除了因高的取样频率引起的问题并保证了高效编码性能。     

"Push-the-Error" Algorithm for Nonlinear n-Term Approximation

This paper is concerned with further developing and refining the analysis of a recent algorithmic paradigm for nonlinear approximation, termed the "Push-the-Error" scheme. It is especially designed to deal with L_∞-approximation in a multilevel framework. The original version is extended considerably to cover all commonly used multiresolution frameworks. The main conceptually new result is the proof of the quasi-semi-additivity of the functional N(ε) counting the number of terms needed to achieve accuracy ε. This allows one to show that the improved scheme captures all rates of best n-term approximation.     

Adaptive-Additive Multilevel Methods for Hypersingular Integral Equation

In this article we present the combined adaptive-additive multilevel methods for the Galerkin approximation of hypersingular integral equation on the interval o = ( m 1,1). We also derive an efficient and reliable a posteriori error estimate for the error between the exact solution u and the approximated multilevel solution $ \tilde u_ {\cal M} $ , measuring locally the quality of $ \tilde u_ {\cal M} $ . The algorithm is carefully designed to obtain minimal complexity. A limitation of our analysis approach is that the meshes must be assumed to be quasi-uniform.     

Regularization in Sobolev Spaces with Fractional Order

We study the minimization of a quadratic functional where the Tichonov regularization term is an H ^s -norm with a fractional s > 0. Moreover, pointwise bounds for the unknown solution are given. A multilevel approach as an equivalent norm concept is introduced. We show higher regularity of the solution of the variational inequality. This regularity is used to show the existence of regular Lagrange multipliers in function space. The theory is illustrated by two applications: a Dirichlet boundary control problem and a parameter identification problem.     

Finite Volume Multilevel Approximation of the Shallow Water Equations

The authors consider a simple transport equation in one-dimensional space and the linearized shallow water equations in two-dimensional space, and describe and implement a multilevel finite-volume discretization in the context of the utilization of the incremental unknowns. The numerical stability of the method is proved in both cases.     

MIMO系统中STTC译码的一种改进型算法

本文对MIMO系统中用于STTC编码器的VA译码算法进行了改进,建立了节点度量的递推方程,并给出了分枝转移的度量方法。改进后的VA算法适用于已经估计出MIMO系统中信道转移阵的条件下。相比于标准的STTC译码算法,改进后的算法可以在一根接收天线上独立进行,并且节点度量可以通过递推方程进行累积。当多根天线独立译码后,可以进一步进行后续比较以再次降低误码率。仿真结果显示：改进VA在比特误码性能上与标准VA算法接近,但是在分段度量计算时收敛速度要远快于标准VA。     

Efficient Coding Unit and Prediction Unit Decision Algorithm for Multiview Video Coding

To aim at higher coding efficiency for multiview video coding, the multiview video with a modified high efficiency video coding (MV-HEVC) codec is proposed to encode the dependent views. However, the c...     

Electromagnetic spectrum chipless radio frequency identification: A review

Over the past few years, Radio Frequency IDentification (RFID) has stridden significantly due to its adoption in many business and daily life activities. RFID empowers end-to-end and item-by-item visibility, letting the customers or decision-makers effectively trail the personnel and resources for improved management. Significant research and development in this area have transformed the inexpensive, miniaturized technology of RFIDs without chip inside. Chipless Radio Frequency IDentification (CRFID) is a unique wireless technology based on radar principle to sense, identify, and track the objects. CRFIDs are simplified and miniaturized tags of traditional RFID, which can widely be used in small and cheap objects/applications in our daily life. This paper reviews the definition, principle, and most recent development in CRFIDs. Based on the reported researches, the ElectroMagnetic Spectrum (EMS) method is typical, which has been concerned by many RFID researchers. Therefore, this paper reviews different types of EMS CRFID tag and classifies these tags based on structure design emphasizing their significant geometries in comparison with performance parameters. Antenna and coding methods of the EMS CRFID are also elaborated, contrasting the tag capacity and coding performance. Finally, we briefly summarize the challenges and limitations in this emerging field and look forward to the prospects of future CRFID.     

Toward Meaningful Connectivity: Using Multilevel Communication Research to Reframe Digital Inequality

Digital inequality, or unequal access to the Internet and technologies that connect to it, has preoccupied communication scholars since the Internet's introduction into popular culture. The relationships between digital and broader social inequalities suggest that meaningful digital connectivity—that is, having the technical skills necessary to engage technology and mobilize information resources to address everyday needs—can empower socially disenfranchised individuals, families, and communities to address challenges related to those disparities. In this essay, we overview the arc of communication research on technology engagement and its consequences. On this foundation, we argue why multilevel research that accounts for individual‐, family‐, and community‐level influences on meaningful digital connectivity is the best path forward for research on digital inequality.