Device reliability under electrical stress and photo response of oxide TFTs

Abstract— The stability of oxide TFTs has been the main focus of this research and is probably the most crucial requirement for the successful application to flat‐panel displays. Although the high Fermi level of oxide semiconductors makes TFTs basically stable under electrical stress, the device reliability under diverse variations of electrical stress is affected by materials such as active semiconductors and gate insulators, processes for the formation of back/front channels and passivation layers, and device configurations among other things. How these factors affect the device reliability have been investigated and a review of the stability is presented. In addition, several categories of the light instability of oxide TFTs is presented and the origin is discussed.     

Network coding-based reliable multicast in wireless networks

Reliable multicast, the lossless dissemination of data from one sender to a group of receivers, has a wide range of important applications. Recently, network coding has been applied to the reliable multicast in wireless networks, where multiple lost packets with distinct intended receivers are XOR-ed together as one packet and forwarded via single retransmission, resulting in a significant reduction of bandwidth consumption. However, the simple XOR operation cannot fully exploit the potential coding opportunities and finding the optimal set of lost packets for XOR-ing is a complex NP-complete optimization problem. In this work, we intend to move beyond the simple XOR to more general coding operations. Specifically, we propose two new schemes (a static scheme which repeatedly retransmits one coding packet until all intended receivers receive it and a dynamic scheme which updates the coding packet once one or more receivers receive it) to encode packets with more general coding operations, which not only can encode lost packets with common intended receivers together to fully exploit the potential coding opportunities but also have polynomial-time complexity. We demonstrate, through both analytical and simulation results, that the proposed schemes can more greatly reduce the bandwidth requirement than the available coding-based schemes, especially in the case of high packet loss probabilities and a larger number of receivers. This reduction can vary from a few percents to over 15% depending on the packet loss probabilities and the number of receivers.     

中国传统色彩在环境空间设计中的应用

传统色彩是某一民族特有的具有地域文化意味的色谱系统及其组合,是自然、社会、审美心理历史积淀的结果。同时,它是现代环境设计的灵感之源,成为深化设计语言的重要途径和手段。中国的色彩文化历史悠久,文化底蕴丰厚,是深化设计语言,提高文化品位的重要组成部分。本文试图探求传统色彩的文化内涵,探讨传统色彩与现代环境设计之间的深层关系,进而在现代设计中进一步传承和发展传统色彩。     

Numerical inversions of a source term in the FADE with a Dirichlet boundary condition using final observations

This paper deals with an inverse problem of determining a source term in the one-dimensional fractional advection-dispersion equation (FADE) with a Dirichlet boundary condition on a finite domain, using final observations. On the basis of the shifted Grünwald formula, a finite difference scheme for the forward problem of the FADE is given, by means of which the source magnitude depending upon the space variable is reconstructed numerically by applying an optimal perturbation regularization algorithm. Numerical inversions with noisy data are carried out for the unknowns taking three functional forms: polynomials, trigonometric functions and index functions. The reconstruction results show that the inversion algorithm is efficient for the inverse problem of determining source terms in a FADE, and the algorithm is also stable for additional data having random noises.     

Plasmonic enhanced fluorescence spectroscopy using side-polished microstructured optical fiber

We report excitation of surface plasmon in a gold-coated side-polished D-shape microstructure optical fiber (MOF). As the leaky evanescent field from the fiber core becomes highly localized by the plasmon wave, its intensity also gets amplified significantly. Here we demonstrate an efficient use of this intensified field as excitation in fluorescence spectroscopy. The so-called plasmonic enhanced fluorescence emission from Rhodamine B has been investigated experimentally. First, plasmonic effect alone was found to provide an immediate fluorescence enhancement factor of two. Second, experimental results show a good agreement with theoretical modeling. Strong evanescent field generation and surface enhancement with simple metallic coating makes this fiber based device a good candidate for compact fluorescence spectroscopy.     

Information Seeking Can Be Social

For reasons ranging from obligation to curiosity, users have a strong inclination to seek information from others during the search process. Search systems using statistical analytics over traces left behind by others can help support the search experience.     

Comparison of individual,ensemble and integrated ensemble machine learning methods to predict China’s SME credit risk in supply chain finance

Supply chain finance (SCF) becomes more important for small- and medium-sized enterprises (SMEs) due to global credit crunch, supply chain financing woes and tightening credit criteria for corporate lending. Currently, predicting SME credit risk is significant for guaranteeing SCF in smooth operation. In this paper, we apply six methods, i.e., one individual machine learning (IML, i.e., decision tree) method, three ensemble machine learning methods [EML, i.e., bagging, boosting, and random subspace (RS)], and two integrated ensemble machine learning methods (IEML, i.e., RS–boosting and multi-boosting), to predict SMEs credit risk in SCF and compare the effectiveness and feasibility of six methods. In the experiment, we choose the quarterly financial and non-financial data of 48 listed SMEs from Small and Medium Enterprise Board of Shenzhen Stock Exchange, six listed core enterprises (CEs) from Shanghai Stock Exchange and three listed CEs from Shenzhen Stock Exchange during the period of 2012–2013 as the empirical samples. Experimental results reveal that the IEML methods acquire better performance than IML and EML method. In particular, RS–boosting is the best method to predict SMEs credit risk among six methods.

     

Novel in-line WAT processing of 55 nm CIS product and effect of process waiting time on void growth at interface of SiCN with copper capping layer

The WAT (wafer acceptance test) is the last examination that is performed before a wafer or a chip fab out to ensure the quality and stability of chip performance. In 55 nm CIS (CMOS Image Sensor) technology, a highly smooth wafer surface is critical for the BSI (backside illumination) process. The traditional WAT process cannot be used; rather the in-line WAT must be performed during the process for forming copper interconnect. However, increasing the processing time increases the period of exposure of the copper interconnect to air, which is called the Q-time, affecting the reliability of copper interconnect. Nitrogen-doped silicon carbide (also called NDC or SiCN) has been used to fabricate copper diffusion barrier films. PECVD SiCN dielectric has a promisingly low dielectric constant for use as a copper diffusion barrier. Copper diffusion barrier films comprise one or more layers of silicon carbide. Covering a copper layer with a single thin NDC pre-layer significantly increases the maximum allowable Q-time for wafer probing. However, after the Q-time, a void forms between NDC layer and the NDC pre-layer. This work proposes a new two-step NDC process and the optimization of the thickness of the NDC pre-layer. The process has the advantages of providing a high stability for parametric test and a long allowable Q-time. These advantages are achieved by changing the thickness of the NDC pre-layer. This new approach has been analyzed using TEM and by performing parametric tests, and the feasibility has been confirmed experimentally. No void is formed between the NDC layers and a high test stability is achieved when the thickness of the NDC pre-layer is 120 Å.     

An auto-encoder-based summarization algorithm for unstructured videos

Multimedia Tools and Applications - Video summarization is an effective way to quick view videos and relieve the pressure of videos storage. However the traditional algorithms are hardly adapted to...     

基于修正变分法开孔板和加强板结构的自由振动分析

为研究船舶开孔板和加强板结构的振动特性,用1阶剪切变形板理论描述各向同性板的位移场,并采用修正变分原理和区域分解方法建立板的离散动力学模型.每一块子域板的位移和转角分量通过第一类切比雪夫正交多项式展开.针对加强板模型,将该方法获得的结果与已经发表的文献和有限元商用软件计算结果进行对比,验证该方法的收敛性和正确性.基于修正变分法探讨多种开孔和加强板模型的自由振动特性,充分说明该数理模型和半解析方法是一种适合处理复杂板结构问题的数值工具.