产酯酵母诱变育种

产酯酵母稀释液经紫外线照射处理后倾注平皿培养,挑选长出的菌落接种到试管培养,用自制杜氏发酵管通过产二氧化碳数量进行初筛,然后通过生理生化分析,复筛出优良菌株。本方法简单实用,值得发酵工厂菌种工作者参考。     

漫湾电厂6号水轮机蜗壳及钢管工作应力现场测试及结果分析

漫湾水电站是云南电网的主力电源点。确保电站的安全运行对于提高云南电网的安全可靠性意义重大。钢管和蜗壳作为特殊的薄壳压力容器，其运行条件和测试方法均有其特殊性，本文详细阐述了漫湾６号机钢管、蜗壳应力测试结果，对于其它已投入运行而需作钢管、蜗壳应力的测试分析的电站有参考价值。     

基于日志模板的异常检测技术

日志分析是云计算业务平台管理中一项非常重要的工作.日志分析旨在保证云平台的高效性与可用性,传统的人工分析方式存在日志复杂、日志量大等问题.本文提出了一种日志异常检测方法,首先基于编辑距离进行文本聚类形成日志模板,在此基础上构建特征向量,利用弱分类器训练形成得分特征向量,利用得分特征向量与随机森林构建强分类器.实验表明,日志模板与真实模板之间的互信息为0.91,较为接近,利用随机森林构建的强分类器在本文的数据集上表现最好,分类精度达0.94.     

Architecture and Engineering Issues in Building an IP over WDM Networks

The technologies of IP over WDM have presently received increasing attention owing to the rapid growth in Internet traffic and the need for next-generation Internet technologies. The challenge now is how to integrate the services of IP over WDM optical networks to take full advantages of WDM technologies and IP technologies, and yield a high-throughput optical platform directly underpinning next generation data networks. This article discusses some of the architecture and technology issues for the design of IP over WDM optical networks.     

Adaptive Bayesian multiuser detection for synchronous CDMA withGaussian and impulsive noise

We consider the problem of simultaneous parameter estimation and data restoration in a synchronous CDMA system in the presence of either additive Gaussian or additive impulsive white noise with unknown parameters. The impulsive noise is modeled by a two-term Gaussian mixture distribution. Bayesian inference of all unknown quantities is made from the superimposed and noisy received signals. The Gibbs sampler (a Markov chain Monte Carlo procedure) is employed to calculate the Bayesian estimates. The basic idea is to generate ergodic random samples from the joint posterior distribution of all unknown and then to average the appropriate samples to obtain the estimates of the unknown quantities. Adaptive Bayesian multiuser detectors based on the Gibbs sampler are derived for both the Gaussian noise synchronous CDMA channel and the impulsive noise synchronous CDMA channel. A salient feature of the proposed adaptive Bayesian multiuser detectors is that they can incorporate the a priori symbol probabilities, and they produce as output the a posteriori symbol probabilities. (That is, they are “soft-input soft-output” algorithms.) Hence, these methods are well suited for iterative processing in a coded system, which allows the adaptive Bayesian multiuser detector to refine its processing based on the information from the decoding stage, and vice versa-a receiver structure termed the adaptive turbo multiuser detector     

GPRS中的一种下行功率控制算法及其改进

通用分组无线业务GPRS是覆盖于GSM移动通信网之上的分组交换数据网络。提出了一种基于载干比C/I的下行功率控制算法。在此基础上,根据载干比C/I与误码率BER的函数关系,提出一种基于误码率的下行功率控制算法。最后,通过使用基于MLD平台设计的仿真软件,分析比较了这两种算法对系统性能的改善。     

Low-Complexity High-Rate Reed--Solomon Block Turbo Codes

This letter considers high-rate block turbo codes (BTC) obtained by concatenation of two single-error-correcting Reed-Solomon (RS) constituent codes. Simulation results show that these codes perform within 1 dB of the theoretical limit for binary transmission over additive white Gaussian noise with a low-complexity decoder. A comparison with Bose-Chaudhuri-Hocquenghem BTCs of similar code rate reveals that RS BTCs have interesting advantages in terms of memory size and decoder complexity for very-high-data-rate decoding architectures.     

室内可见光通信中噪声与干扰的实验与仿真分析

对室内可见光通信中的背景光噪声与干扰进行了实验测试,获得了噪声干扰的典型时域特性;进而模拟分析了背景光噪声与干扰对不同速率信号传输的影响。结果显示,背景光噪声及干扰对室内可见光通信的影响主要表现为直流电平和低频周期性信号,并且低速率数据信号更容易被干扰。通过比较分析几种无线光通信中常用调制方式的功率谱密度,结果表明,由于脉冲位置调制和曼彻斯特编码的低频分量较少,更适合室内可见光通信。