Compiler compatible 5.66 Mb/mm2 8T 1R1W register file in 14 nm FinFET technology

1-read/1-write (1R1W) register file (RF) is a popular memory configuration in modern feature rich SoCs requiring significant amount of embedded memory. A memory compiler is constructed using the 8T RF bitcell spanning a range of instances from 32 b to 72 Kb. An 8T low-leakage bitcell of 0.106 μm² is used in a 14 nm FinFET technology with a 70 nm contacted gate pitch for high-density (HD) two-port (TP) RF memory compiler which achieves 5.66 Mb/mm² array density for a 72 Kb array which is the highest reported density in 14 nm FinFET technology. The density improvement is achieved by using techniques such as leaf-cell optimization (eliminating transistors), better architectural planning, top level connectivity through leaf-cell abutment and minimizing the number of unique leaf-cells. These techniques are fully compatible with memory compiler usage over the required span. Leakage power is minimized by using power-switches without degrading the density mentioned above. Self-induced supply voltage collapse technique is applied for write and a four stack static keeper is used for read Vmin improvement. Fabricated test chips using 14 nm process have demonstrated 2.33 GHz performance at 1.1 V/25 °C operation. Overall V_min of 550 mV is achieved with this design at 25 °C. The inbuilt power-switch improves leakage power by 12x in simulation. Approximately 8% die area of a leading 14 nm SoC in commercialization is occupied by these compiled RF instances.     

一种新颖的CDMA系统下多目标无线定位方法

利用Marginalized粒子滤波算法,处理CDMA(Code Division Multiple Access)系统中多目标无线定位及跟踪问题。在CDMA系统中,由于数据的非线性导致了过大的计算复杂度,并影响到定位的精度。论文主要从CDMA系统中多目标联合检测和建立基于边缘化粒子滤波器的数据融合模型两方面进行研究和分析,解决CDMA中多用户的辨别、定位精度和计算复杂度之间的矛盾。仿真结果证明其方法能够保证多目标定位的精度,并极大地减少计算复杂度。     

基于矩阵式变换器的异步电机电流滞环跟踪矢量控制

采用混合控制策略将矩阵式变换器用于驱动和控制异步电机。将矩阵式变换器等效为虚拟交一直一交变换，对其虚拟整流侧采用空间矢量调制方法，对其虚拟逆变侧则采用电流滞环跟踪矢量调制，最后通过开关译码得到矩阵变换器的9个开关管的控制信号。仿真结果验证了控制方法的可行性和有效性：调速系统具有较好的动态特性，电网输入端功率因数为1。     

在PLC控制系统中的系统思维

目前，随着微电子技术的发展，PLC控制系统的应用已经远远突破了早期的逻辑控制，从硬件到软件、从单机到系统、从逻辑控制到过程控制，功能异常强大，产品非常丰富，以西门子、罗克维尔、施耐德等几个知名品牌来说，产品系列非常齐全。几乎每个系列又都覆盖大、中、小各种规模的应用场合，给使用者全面、快速地掌握PLC的应用增加了很大难度。为阐述方便，本文从西门子S7系列PLC着手，希望从系统思维的角度来全面分析PLC控制系统在各种应用场合中产品选型与解决方案。     

Landscaping of highway medians and roadway safety at unsignalized intersections

Well-planted and maintained landscaping can help reduce driving stress, provide better visual quality, and decrease over speeding, thus improving roadway safety. Florida Department of Transportation (FDOT) Standard Index (SI-546) is one of the more demanding standards in the U.S. for landscaping design criteria at highway medians near intersections. The purposes of this study were to (1) empirically evaluate the safety results of SI-546 at unsignalized intersections and (2) quantify the impacts of geometrics, traffic, and landscaping design features on total crashes and injury plus fatal crashes. The studied unsignalized intersections were divided into (1) those without median trees near intersections, (2) those with median trees near intersections that were compliant with SI-546, and (3) those with median trees near intersections that were non-compliant with SI-546. A total of 72 intersections were selected, for which five-year crash data from 2006–2010 were collected.The sites that were compliant with SI-546 showed the best safety performance in terms of the lowest crash counts and crash rates. Four crash predictive models—two for total crashes and two for injury crashes—were developed. The results indicated that improperly planted and maintained median trees near highway intersections can increase the total number of crashes and injury plus fatal crashes at a 90% confidence level; no significant difference could be found in crash rates between sites that were compliant with SI-546 and sites without trees. All other conditions remaining the same, an intersection with trees that was not compliant with SI-546 had 63% more crashes and almost doubled injury plus fatal crashes than those at intersections without trees. The study indicates that appropriate landscaping in highway medians near intersections can be an engineering technology that not only improves roadway environmental quality but also maintains intersection safety.     

大跨度柱形屋盖风荷载数值模拟研究

大跨钢结构屋盖具有柔性大、阻尼小的特点,为风敏感结构。CFD数值模拟方法是近年来发展起来的一种风荷载研究手段,本文基于Fluent软件平台,利用雷诺应力湍流模型(RSM)对某钢结构大跨钢结构屋盖进行了风场数值模拟研究,得出屋盖结构体型系数和风速分布,为结构设计人员确定屋盖结构表面风荷载时提供参考。     

基于MATLAB的Nomarski棱镜优化设计

根据落射式微分干涉相衬显微镜中Nomarski棱镜的光学原理,通过几何光学运算,推导出棱镜主要结构参数的理论关系式,利用MATLAB程序将关系式转化为二维曲线,再根据关系曲线的变化趋势来确定适合于Nomarski棱镜主要结构的参数取值范围,从而实现优化设计的目的。     

论ISO14064与广东省温室气体减排

在介绍ISO14064来源的基础上,说明ISO14064的组成、目的和实施要求等关键问题。分析广东省温室气体减排现状,提出广东企业或其它组织实施ISO14064所需注意和解决的关键问题。     

金沙洲大桥主桥设计

主要介绍了金沙洲大桥主桥的结构尺寸及结构设计特点,并采用桥梁计算程序对主桥进行结构分析和各施工阶段的验算,计算分析结果表明主桥运营阶段受力状态均满足规范要求,结构设计较为合理。     

旧路改造软基处理方法研究

以中山市北外环道路整治工程为研究对象,介绍了旧路改造沉降处理常用的高压旋喷桩、预应力管桩及CFG桩处理方案,并对三种方案进行了对比分析,总结了各方案的优缺点,以期根据工程的实际情况选择出合适的软基处理方案。