真空光镊系统及其在精密测量中的研究进展

光镊具有非接触、低损伤和适用范围广等特性,被广泛应用于生命科学、纳米科技等领域。光镊系统通过调制束缚光场操控机械振子的运动,借助光动量和角动量的检测获取振子的运动状态,以实现对振子物理参量的精密测量。与传统液体光镊系统不同,真空光镊系统中的机械振子可获得与外界环境近乎完全隔离的状态,具有超高灵敏度的探测能力,是精密测量和基础物理研究的理想平台。首先介绍了真空光镊系统相关的基础理论,然后介绍了真空光镊系统的实验配置方案及其在精密测量中的典型应用,最后总结了真空光镊系统的发展现状,并给出了未来的发展建议。     

高速铣削工件表面粗糙度遗传-BP神经网络建模

遗传算法作为一种高效,并行的全局搜索优化方法,非常适合用于BP神经网络学习率的优化.文中通过基于遗传算法和BP神经网络提出了遗传-BP神经网络.以实验1、实验2、实验5、实验6、实验9、实验11、实验13和实验15下的高速铣削试验数据构建用于高速铣削工件表面粗糙度建模的训练样本对,并用回归的高速铣削工件表面粗糙度预测模...     

基于Prophet人工智能算法的网络潮汐效应预测研究

本文使用Prophet人工智能算法研究与预测移动通信网络"潮汐效应"现象,探索网络"潮汐效应"在优化网络资源配置实现网络降本增效的作用.Prophet人工智能算法是一种简单有效且易于实现的人工智能算法.本文通过Facebook的人工智能开源框架fbprophet,研究4G网络PRB利用率等网络资源指标的"潮汐效应",并...     

轻量级UPF N4接口开放性技术研究与应用

在阐述5G核心网架构与UPF网元的功能,以及N4接口开放在5G赋能垂直行业方面的重要影响的基础上,重点说明了运营商在推进轻量级UPF N4接口与5G核心网对接验证方面所做的工作,从技术层面证明了N4接口开放的可行性,进而说明了3种面向行业的5G应用部署模式,并结合实际案例进行分析.最后针对当前存在的问题,提出了在推进N...     

Chip‐interleaving direct sequence spread spectrum system over Rician multipath fading channels

Chip interleaving (CI) is a unique technique to exploit time diversity in direct sequence spread spectrum (DS/SS)‐based systems operating in fading environments. In order to facilitate design of CI systems in various fading situations, we present a performance analysis for CI DS/SS system over Rician multipath time‐varying fading channels. We derive the analytical bit error rate (BER) expression for CI DS/SS to allow fast and accurate evaluation of BER performance based on the interleaving depth selected, spreading codes employed, and the time correlation function of the channel. We then discuss some ideal cases by using the analytical results to reveal some of the insights presented in the performance analysis. For the purpose of comparison, we also obtain the BER expression for conventional DS/SS system as a special case of CI system with an interleaving depth of one. Using numerical examples, we verify the analytical results with computer simulations and illustrate the BER performance behavior of CI DS/SS system with varying interleaving depth for all possible combinations of two sets of spreading codes of different type and two different time correlation functions of the channel. Copyright © 2011 John Wiley & Sons, Ltd.     

Advanced Theragenerative Biomaterials with Therapeutic and Regeneration Multifunctionality

All tissues and organs can be affected by diseases, and treatments for these diseases can cause damage to surrounding healthy tissues and organs. Therefore, treatment is required that involves disease therapy alongside tissue/organ regeneration. The design, construction, and biomedical applications of biomaterial platforms with both disease‐therapeutic and tissue‐regeneration multifunctionalities are in demand, which are herein referred to as theragenerative (abbreviation of therapy and regeneration) biomaterials. Due to the rapid development of theragenerative biomaterials in versatile biomedical applications, this progress report aims to summarize, discuss, and highlight the rational construction of distinctive theragenerative biomaterials with intrinsic therapeutic performance and tissue‐regeneration bioactivity. Based on the intrinsic response to either external physical triggers (e.g., photonic response or magnetic‐field response) or endogenous disease microenvironments (e.g., mild acidity or overexpressed hydrogen peroxide) and tissue‐regeneration bioactivity, these theragenerative biomaterials are extensively explored in various biomedical fields, including bone‐tumor therapy/regeneration, bone antibacterial therapy/regeneration, skin‐tumor therapy/regeneration, skin antibacterial therapy/regeneration, breast‐tumor therapy/adipose‐tissue regeneration, and osteoarticular‐tuberculosis therapy/bone‐tissue regeneration. The challenges faced and future developments of these distinctive theragenerative biomaterials are discussed, as are methods for further promoting their clinical translation.     

CCD传感器实时检测技术在微细电火花加工机床上应用的优势

CCD传感器实时检测系统是一套基于光电检测技术的质量监测仪器,可用于实时观测和测量被加工工件,特别适合安装应用于微细电火花加工机床。此系统利用CCD（Charge-CoupleDevice）传感器对工件进行非接触式测量,提高了微细电火花加工机床的工作效率和质量。此文对这一系统进行讨论,分析了其特点和优越性。     

侵彻过程中的墙角效应

对侵彻火箭弹的引信中发火决策方式进行总结。利用有限元动力学仿真软件Ls-Dyna完成对火箭弹以不同角度斜侵彻复杂目标过程中遇到墙角时的动力学仿真。根据仿真得到的位移,加速度数据,对单传感器的火箭弹侵彻引信进行讨论,发现其中存在的一些问题,如无法分辨水平和竖直目标,无法探测跳弹等情况,即墙角效应对于侵彻引信的影响,同时根据仿真数据分析了引信中利用两个传感器测量的优势。     

基于LLE与Fisher线性判别的人脸识别算法

为了提高基于流形学习理论人脸识别算法的识别率,采用一种将非线性降维与Fisher线性判别相结合的方法。首先利用邻域嵌入算法,将人脸图像测试和训练集的维数降低到合适维度,然后使用Fisher线性判别进行人脸数据集特征的提取,最后将测试集人脸图像特征和训练集人脸图像特征,使用最近邻分类器进行分类。在公开的Olivettifaces和ORL人脸图像数据库上,分别将该算法与几种经典基于流形学习理论的人脸识别算法进行了对比实验,实验结果表明当近邻数比较大时本算法识别率是最高的。