分集接收MLSE算法性能分析

基于频率选择性衰落信道,改进了以一般多径信道为模型的传统MLSE算法,提出了将分集接收方法与MLSE算法联合的改进MLSE算法;通过建立与分析新算法模型,推导得到新的误码率性能上界;对一般多径条件下的传统MLSE和在频率选择性衰落信道条件下新算法的误码率性能及性能界进行了仿真.仿真结果表明,使用分集接收的新算法性能界与...     

基于多样化进化策略的基因表达式编程算法

针对传统GEP（Gene Expression Programming）算法的未成熟收敛以及陷入局部最优问题,提出一种基于多样化进化策略的基因表达式编程算法（DS-GEP：Gene Expression Programming based on diversified develop-ment strategy）。该算法通过基因空间均匀分布策略,自适应地交叉和变异算子以及淘汰算子等方法,对种群给予不同的进化策略,以保持种群的多样性,从而增强算法的寻优能力。通过对函数挖掘的实验证明,多样化进化策略各个部分均对改善挖掘效率发挥了作用,提高了DS-GEP函数挖掘算法的成功率。与传统GEP算法相比较,该算法的平均成功进化代数缩短了11%,成功进化时间缩短了8%,进化成功率提高了20%。     

基因表达式编程种群多样性自适应调控算法

为了解决基因表达式编程GEP种群多样性控制问题,提出了一种新的带权种群多样性的自适应调控方法。设计了带权的种群多样性测度方法,详细分析了选择、交叉及变异算子对种群多样性的影响。提出了初始种群的多样化算法DAIP,以保证初始种群多样性的最大化。设计了自适应的交叉和变异算子,提出了种群多样性自适应调控算法APDTA,使种群在进化过程中维持合适的种群多样性,进而提高进化效率。实验验证了APDTA的有效性。     

五氯酚在厌氧生物体系中的降解及反馈作用

为探讨厌氧系统降解五氯酚(PCP)能力及PCP对厌氧系统的毒性影响,采用UASB反应器进行了PCP模拟污水连续流试验,考察了不同PCP浓度及负荷条件下系统对PCP和COD的降解去除规律,揭示了PCP对系统产酸相和产甲烷相影响状况.结果表明,在进水PCP含量从无到开始加入、PCP浓度提高以及PCP负荷提高3个冲击变化阶段,厌氧系统对PCP和COD的去除率均表现出先迅速降低后缓慢升高的变化趋势,运行稳定后PCP和COD的去除率分别达91.2%和83.5%以上.PCP对厌氧系统中微生物种群产生影响,使系统产酸菌由丁酸型菌群为主逐渐演替为丙酸型菌群为主,PCP对系统产甲烷菌活性产生明显抑制,甲烷产量由PCP加入前的12.1L/d降低至加入后的2.5L/d.     

广义分布式天线系统上行分集性能分析

针对广泛存在于无线通信环境中的阴影效应对系统性能影响非常大的问题,采用与传统的微分集技术相比,能够有效地对抗这种阴影衰落的分布式天线技术来解决这个问题.为了获得该条件下系统的理论性能,分析了采用最大比合并和相干等增益合并分集的广义分布式天线系统.借助lognormal近似法,给出了其中断概率和误码率性能的高精度解析结果.分析表明,在存在阴影衰落的情况下,这种广义分布式天线系统能够同时获得较大的微/宏分集增益,非常适合未来的无线小区环境.     

准正交空时分组码的自适应设计

为了能在满足空时分组码完全分集的同时尽可能降低译码复杂度,提出了准正交空时分组码的自适应设计方案. 在准正交空时分组码的编码结构上添加自适应系数,根据当前信道状态信息计算自适应系数的具体数值. 设计的目的是保证传输的数据符号之间相互正交,彼此没有干扰,从而实现完全分集,并能采用复杂度低的单符号译码方法. 仿真结果表明,准正交空时分组码自适应方案的误码率性能要明显好于采用星座旋转的准正交空时分组码方案,只需要采用有限反馈的方法就能实现近似理想反馈的误码率性能.      

Synergistic Sex Pheromone Components of White-Spotted Tussock Moth, Orgyia thyellina

In 1996, the exotic white-spotted tussock moth (WSTM), Orgyia thyellina (Lepidoptera: Lymantriidae), was discovered in Auckland, New Zealand. Because establishment of WSTM would threaten New Zealand's orchard industry and international trade, eradication of WSTM with microbial insecticide was initiated. To monitor and complement eradication of WSTM by capture of male moths in pheromone-baited traps, pheromone components of female WSTM needed to be identified. Coupled gas chromatographic–electroantennographic detection analysis of pheromone gland extract revealed several compounds that elicited responses from male moth antennae. Mass spectra of the two most EAD-active compounds suggested, and comparative GC-MS of authentic standards confirmed, that they were (Z)-6-heneicosen-11-one (Z6–11-one) and (Z)-6-heneicosen-9-one, the latter termed here thyellinone. In field experiments in Japan, Z6–11-one plus thyellinone at a 100:5 ratio attracted WSTM males, whereas either ketone alone failed to attract a single male moth. Addition of further candidate pheromone components did not enhance attractiveness of the binary blend. Through the 1997–1998 summer, 45,000 commercial trap lures baited with 2000 g of Z6–11-one and 100 g of thyellinone were deployed in Auckland towards eradication of the residual WSTM population.Dedicated to my dear mother in honor of her 75th birthday     

介体型水质BOD生物电化学传感器研究进展

生物化学需氧量(BOD)是目前国际上用来衡量水质有机物污染的重要指标之一。由于水体中氧的溶解度非常低,以电子媒介体代替溶解氧为电子受体的介体型BOD生物电化学传感器以其快速、准确、稳定等优点得到了较快的发展。论述了介体型水质BOD生物电化学传感器的发展现状及研究动态,重点讨论了介体型水质BOD生物电化学传感器的工作原理、构成及类型,分析了不同类型传感器的优缺点,并对其核心部分-微生物膜的制备方法做了比较详细的介绍。     

Activity and stability ofPenicillium cyclopium lipase in surfactant and detergent solutions

Activity and stability of an alkaline lipase fromPenicillium cyclopium var.album (PG 37) were studied in surfactant and detergent solutions. Three anionic surfactants [Na salts of C₁₂SO₄ ^? (sodium dodecyl sulfate), C₁₂ØSO₃/^? (linear alkyl benzene sulfonate), and C₁₁COO^? (laurate)] and four homologous series of nonionic surfactants of C_12–15 polyoxethylenated fatty alcohols (AEO₃, AEO₅, AEO₇, and AEO₉) were evaluated. At a concentration range of 3.2–40 μM, sodium dodecyl sulfate and laurate stimulated the activity of PG 37 lipase. At concentrations greater than 5.6 μM, linear alkylbenzene sulfonate inhibited PG 37 lipase activity. Nonionic surfactants, AEO₅ and AEO₇, in the concentration range of 0.25–20 mM, enhanced and stabilized the activity of PG 37 lipase. The presence of PG 37 lipase in detergent formulaton improved detergency ～20%. The mechanism of inhibition of the lipolytic activity of PG 37 lipase is proposed to be partly due to the formation of inactive (BR)_n-E complex between the hydrophobic moiety of the surfactants and the surface of the lipase. Conversely, formation of a soluble (RB)_n-E complex between the hydrophilic group of the surfactant and lipase may account for the increased lipolytic activity of PG 37 lipase.     

Optimal resource allocation for transmission diversity in multi-radio access networks： a coevolutionary genetic algorithm approach

The next generation wireless communication systems aim at supporting enhanced diversified network access and data transmission abilities via the cooperative integration and unified management of various radio access technologies(RATs).The resource allocation is the core component leading the network system and mobile terminals to the service robustness and performance maximization.In this paper,a numeric optimization model for optimizing terminals’transmission power and allocated RAT bandwidth for maximizing system capacity is proposed with the focal consideration of the multi-radio transmission diversity for parallel transmission through multiple links from diferent RATs,and diferent terminal characteristics on RAT supports.Also,we design a centralized and periodic scheduling algorithm including an improved coevolutionary genetic algorithm for efciently solving the optimization problem.Simulation results demonstrate that our propose algorithm can distinctly enhance the system performance and improve the computational efciency.