考虑下垫面类型的干旱指数比较研究

干旱作为常见的自然灾害，在世界各地发生的频率日渐增加，已对经济发展、农业生产和人类生活等方面产生了严重影响。但是干旱的类型较多，包括气象干旱、土壤干旱、水文干旱、农田干旱等，无法用单个干旱指数对不同类型的干旱进行监测。按照干旱发生类型，利用气象干旱指数（Standardized Precipitation Index SPI）、土壤水分干旱指数（Soil Moisture Index, SMI）和蒸发压力干旱指数（Evaporative Stress Index, ESI）对美国的旱情进行监测。研究结果表明：不同干旱指数之间呈显著相关，相关系数R在0.7以上。ESI整体监测精度较高，它能够真实反映地表水分盈亏状况，同时与遥感数据结合，可以实现从田块到全球不同尺度干旱实时监测。不同植被类型覆盖下垫面对不同类型干旱响应存在较大差异，草地下垫面对不同类型的干旱响应较为一致，但是随着地上生物量的增加，不同干旱指数监测结果之间差异逐渐增大。因此，在干旱监测时需要考虑植被的结构特征，植被与气候之间的相互作用，才能具体分析不同下垫面的受灾情况，进一步考虑更适合的方法以及干旱指数监测不同下垫面的干旱情况。     

SNMPvl、SNMPv2c和SNMPv3协议结构的分析与比较

本文从数据定义语言、管理信息库、协议操作规范及安全与访问控制这四个方面,对SNMP协议的三个版本进行了横向比较,有助于对SNMP协议的了解和使用.     

SNMP协议及其应用开发

随着计算机网络的发展,人们日益认识到网络管理的重要性。本文较详细地介绍了网络管理事实上的标准－－ＳＮＭＰ协议的基本原理和组成,接着介绍了用来实现ＳＮＭＰ协议的ＡｄｖｅｎｔＮｅｔ ＳＮＭＰｖ３ Ｐａｃｋａｇｅ,最后给出了利用ＡｄｖｅｎｔＮｅｔ ＳＮＭＰ包,用Ｊａｖａ语言编写的完成基本ＳＮＭＰ的Ｇｅｔ操作的应用程序实例。     

Impact of geometry on stretchable meandered interconnect uniaxial tensile extension fatigue reliability

This work investigates the impact of geometry on the reliability of a high conductivity, meandered, stretchable interconnect. Meandered copper conductor interconnects of varying geometries that have been encapsulated into a PDMS matrix, are evaluated for reliability under tensile stretching conditions to 10% elongation. We present results that support our earlier findings by experiment and FEM simulation. Following, we vary interconnect parameters related to the encapsulation geometry, such as encapsulation hardness, thickness and stretchable zone perimeter, to assess impact on fatigue life of the embedded meandered copper lines. Results confirm and refine the prior simulation findings. Combinations of interconnect geometry parameters critical for stretching reliability are identified. Among others, we find that the meander radius (R) and encapsulation thickness are strongly coupled, causing very large meanders with thick encapsulation to fail very early. We show that, depending on the design of the meander transition, the characteristic life of an interconnect can differ 50 times under moderate, 10% cyclic elongation. Finally, we indicate the significance of our findings for the design of reliable, stretchable electronic systems.     

一种改进的SMI波束形成算法

协方差矩阵求逆(SMI)波束形成算法利用协方差矩阵求逆的方法求得权值,其收敛速度快,但是当期望信号信噪比增加时,算法性能急剧下降。本文提出一种改进的SMI算法,它增加了一个可以调节这种波束形成器权向量中的增强因子,从而使算法在期望信号信噪比增加的条件下也实现。     

基于SMI－CMA联合自适应算法的性能分析

恒模算法(CMA)被广泛地应用到盲自适应波束形成中，除了传输信号波形具有恒定的包络外．CMA不需要先验知识。基于SMI—CMA算法的恒模(CM)阵列级联的结构，由SMI算法决定CMA的初始权向量．系统可以分离多个同信道信源，在干扰信号较强时，仍有稳定的SINR输出，具有较好的收敛速度。仿真结果也证明了SMI—CMA算法具有较强的稳健型和较快的收敛速度。     

中钢与住友金属关于和歌山上游生产线合作分析

介绍了中钢和住友金属关于和歌山上游生产线的合作内容，分析了合作的背景以及合作将产生的影响。指出这是一个新的、值得借鉴的合作模式。     

自适应波束形成采样矩阵求逆算法的改进

采样矩阵求逆(SMI)算法是自适应算法中的一个分类。由于该算法需要知道接收信号的波达方向角度,因此属于非盲算法。在现有采样矩阵求逆算法的基础上进行了2项改进,提出了对协方差矩阵进行信号子空间分解再加权的方法,有效改善了输出期望信号的主瓣增益和输出信干噪比;同时针对传统SMI算法无法应用于相干信号源的情况做了进一步改进,通过对相干信号进行解相关,解决了这一问题。     

A computational model for ranking cloud service providers using hypergraph based techniques

In a cloud marketplace, the existence of wide range of Cloud Service Providers (CSPs) makes it hard for the Cloud Users (CUs) to find an appropriate CSP based on their requirements. The design of a suitable service selection framework helps the users in the selection of a suitable CSP, while motivating the CSPs to satisfy the assured Service Level Agreement (SLA) and enhance the Quality of Service (QoS). Existing service selection models employ random assignment of weights to the QoS attributes, replacement of missing data by random values, etc. which results in an inaccurate ranking of the CSPs. Moreover, these models have high computational overhead. In this study, a novel cloud service selection architecture, Hypergraph based Computational Model (HGCM) and Minimum Distance-Helly Property (MDHP) algorithm have been proposed for ranking the cloud service providers. Helly property of the hypergraph had been used to assign weights to the attributes and reduce the complexity of the ranking model, while arithmetic residue and Expectation–Maximization (EM) algorithms were used to impute missing values. Experimental results provided by MDHP under different case studies (dataset used by various research communities and synthetic dataset) confirms the ranking algorithm to be scalable and computationally attractive.     

添加结构支撑约束的一种快速重分析算法

在结构设计优化中经常将结构支撑作为设计优化对象,支撑条件的修改导致系统的求解规模发生改变,使得快速准确分析修改后结构的响应成为一个挑战.本文发展了连续矩阵逆(SMI)方法,提出了添加结构支撑约束重分析的一种快速算法.该方法利用支撑修改后对应刚度矩阵的对称性,有效缩减了计算量.数值算例表明,本文方法能够快速给出精确结果.