[智能感知]基于粒子群优化支持向量机算法的行驶工况识别及应用

实车采集4种典型行驶工况数据,采用随机数法提取并扩充行驶工况识别训练及测试样本,利用多元统计理论对数据进行处理,基于粒子群优化的支持向量机(PSO-SVM)算法来进行行驶工况识别,分析了识别周期及更新周期对行驶工况在线识别精度的影响。将行驶工况识别技术应用在插电式混合动力汽车的能量管理策略中。仿真结果表明,相对于未采用行驶工况识别技术以及采用传统SVM算法进行工况识别的能量管理策略,基于PSO-SVM算法工况识别的能量管理策略使整车燃油经济性分别提高9.836%和4.348%,并且电池荷电状态(SOC)变化相对平稳,有利于提高系统效率和延长电池寿命。     

Subjective evaluation of speech compression codecs and other non-linear voice-path devices for telephony applications

Subjective assessment plays a key role in characterizing the voice quality of new telecommunications devices, both individually and in conjunction with other network equipment. This article discusses subjective test methods for speech quality evaluation with a particular focus on methods used to evaluate speech compression codecs and other non-linear DSP techniques used in modern communications networks. Understanding test designs and trade-offs will help codec designers and network planners appreciate what subjective tests are capable of, what the results of the tests mean, and how the results of different tests may be compared.The general categories of listening tests and conversation tests are compared, ACR and DCR methods are considered, and the details of listening test design, testing procedure, data analysis, and interpretation of results are discussed in detail.     

A Fast and Precise Blind I/Q Mismatch Compensation for Image Rejection in Direct‐Conversion Receiver

In this paper, we propose a new digital blind in‐phase/quadrature‐phase (I/Q) mismatch compensation technique for image rejection in a direct‐conversion receiver (DCR). The proposed image‐rejection circuit adopts DC offset cancellation and a sign‐sign least mean squares (LMS) algorithm with a unique step size adaptation both for a fast and precise I/Q mismatch estimation. In addition, several performance‐optimizing design considerations related to accuracy, speed, and hardware simplicity are discussed. The implementation of the proposed circuit in an FPGA results in an image‐rejection ratio (IRR) of 65 dB, which is the best performance with modulated signals, along with an adaptation time of 0.9 seconds, which is a tenfold increase in the compensation speed as compared to previously reported circuits. The proposed technique will be a promising solution in the area of image rejection to increase both the speed and accuracy of future DCRs.     

（英）STI埋层的高光电流和低暗计数率单光子雪崩二极管

本文研究和分析了一种0.18-μm CMOS工艺单光子雪崩二极管（SPAD）,其结构能抑制过早的边缘击穿（PEB）,同时获得较大的光电流和低的暗计数率（DCR）。该SPAD由p-well/deep n-well的感光结,deep n-well向上扩散形成的区域和边缘Shallow Trench Isolation（STI）共同形成的保护环组成。通过测试确定了与光电流和暗率有关的STI层的大小。结果证明,在STI层与保护环之间的重叠区域为1-μm 时,SPAD的暗计数率和光电流最佳。此外,直径为10-μm的圆形SPAD器件的暗计数率为208Hz,且在波长为510nm时峰值光子探测概率为20.8%,此时具有低的暗计数率和高的探测效率以及宽的光谱响应特性。     

双机架在线平整机组过焊缝技术应用

双机架平整机组二次冷轧过程中,极易发生断带情况。分析了首钢京唐公司在线双机架平整机组过焊缝过程中月牙区域断带的原因,一是局部浪形过大,导致部分形成应力集中;二是在线DCR平整过程中张力较大,局部应力集中,导致带钢屈服失稳,拉断带钢。通过调整辊系的水平度和垂直度,制定无带钢标定和轧制力偏差异常的临时控制措施;同时开发过焊缝自动降低张力程序,将机组过焊缝平整机前后张力降低20%,机组的断带率从2次/月降至0次/月。     

基于DCR假设的KDM-CCA安全性

加密方案的KDM（Key-Dependent Message）安全性定义依赖于某一特定的函数族[F]。通过引入一类新的函数族,证明了在两个用户的情形下,Cramer和Shoup提出了基于DCR（Decisional Composite Residuosity）假设的方案（以下称为CS-DCR方案）,关于这类新函数族具有KDM-CCA安全性。由于CS-DCR方案本身非常得高效,因此,获得了兼有高效性和（相应）KDM-CCA安全性的加密方案。     

A Joint Scheme of AGC and Gain/Phase Mismatch Compensation for QPSK DCR

This paper presents a simple gain/phase blind compensation algorithm with an automatic gain control (AGC) function for the adoption of the AGC function and compensation for gain/phase imbalances in quadrature phase shift keying (QPSK) direct conversion receivers (DCRs). The AGC function is interactively operated with the compensation algorithm for gain/phase imbalances. By detecting the gain sum and difference values between the I‐channel and Q‐channel, the combined AGC and gain imbalance compensation algorithm provides a simpler DCR architecture.     

基于DCR方法的沉砂池右边墙抗震安全评价

本文基于美国陆军工程师兵团EM 1110-2-6053中提出的水工建筑物抗震性能需求能力比(DCR,demand to capacity ratio)评价方法,对某水电站沉砂池综合抗震性能进行了评价。结果表明,在OBE下,沉砂池右边墙的抗剪性能、抗弯性能、抗滑动稳定和抗倾覆稳定性均能满足设计要求。而在MDE下,尽管沉砂池截面抗弯性能良好,但其右边墙的抗剪性能难以满足设计要求,需要对结构断面或配筋进行调整;且其可能发生滑动失稳和倾覆失稳破坏,需要进一步开展非线性动力分析。     

电力电缆载流量模型及其应用研究

研究了电力电缆载流量算法模型的原理、分类方法和特性,并分析了多个实用的模型及其应用;特别介绍了SCR和DCR电缆模型、综合分析方法在电缆系统的设计、在线监测和运行优化方面的应用,并提供了一个应用案例。     

基于DCR标准的数字对讲系统设计

本文研究了DCR标准的信源编码算法——AMBE算法和信道编码算法——删除卷积码,采用AMBE3000声码器和数字专网移动通信专用芯片CMX7141设计了一款遵从DCR标准的数字对讲系统。并对所设计的DCR数字对讲机系统进行仿真和实验验证。实验结果表明：该系统在保证通信的有效性和可靠性的基础上,具有较高的语音通信质量。