关于I_3-半群(Ⅱ)

本文利用半群代数理论及偏序集理论、方法,继续讨论了I_3-半群的若干性质及其幂零性问题。给出了I_3-半群为幂零的若干充要条件,特别是给出了幂零的I_3-半群的序结构特征,完全确定了全序幂零的I_3-半群的结构。     

￣（45）Ca跨膜流动测定技术用于中药钙拮抗作用的研究

应用￣（４５）Ｃａ跨膜流动测定技术研究钙拮抗剂ｖｅｒａｐａｍｉｌ、中药西红花（ＣｒｏｃｕｓＳａｔｉｖｕｓＬ．）、“地奥心血康”（ＤＡＸＸＫ）、川红花（ＣａｒｔｈａｍｕｓｔｉｎｃｔｏｒｉｕｓＬ．）及银杏叶（ＧｉｎｋｇｏｂｉｌｏｂａＬ．）等对大鼠主动脉￣（４５）Ｃａ跨膜内流的作用，以确定其对细胞膜Ｃａ￣（２＋）通道影响。实验结果表明：西红花、川红花、ＤＡＸＸＫ对平滑肌细胞膜上电压依赖Ｃａ￣（２＋）通道（ＰＤＣ）和受体操纵Ｃａ￣（２＋）通道（ＲＯＣ）都有阻滞作用，并以西红花的阻滞作用最强；而银杏叶对细胞膜Ｃａ￣（２＋）通道无阻滞作用。     

Collaborative applications based on the internet

The basic concepts of collaborative applications and some relevant aspects about network communications are introduced. With the examples of some collaborative applications developed by us, several technical problems about collaborative applications, such as loss of data packets, unknown IP address and timedelay, are discussed in detail. And the methods of solving these problems are also provided. Supported by International Cooperation Project (Japan, Jincheng Co. Ltd) Fang Rui: born in 1975, Graduate student     

一类来自有限域 GF（16）子群上的高码率的 LDPC码

最近,Sobhani等人利用在有限群上的元素置换方法构造群置换LDPC码,本文在此基础上,给出了一类在有限域GF（16）的子群上构造的高码率的LDPC码,其Tanner图围长至少为8。仿真结果表明,这类码执行性能优于相应类型的随机LDPC码和其代数结构的准循环LDPC码。     

Ho∞-based fault detection for nonlinear networked systems with random packet dropout and probabilistic interval delay

The fault detection problem for the nonlinear networked control system (NCS) with packet dropout and delay is investigated.A nonlinear stochastic system model is proposed to account for the NCS with random packet dropout and networkinduced non-uniformly distributed time-varying delay in both from sensor to controller (S/C) and from controller to actuator (C/A).Based on the obtained NCS model,employing an observer-based fault detection filter as the residual generator,the addressed fault detection problem is converted into an auxiliary nonlinear H∞ control problem.Then,with the help of Lyapunov functional approach,a sufficient condition for the desired fault detection filter is constructed in terms of certain linear matrix inequalities,which depend on not only the delay interval but also the delay interval occurrence rate and successful packet communication rate.Especially,a trade-off phenomenon between the maximum allowable delay bound and successful data packet transmission rate is found,which is typically resulted from the limited bandwidth of communication networks.The effectiveness of the proposed method is demonstrated by a simulation example.     

H_∞-based fault detection for nonlinear networked systems with random packet dropout and probabilistic interval delay

The fault detection problem for the nonlinear networked control system(NCS) with packet dropout and delay is investigated.A nonlinear stochastic system model is proposed to account for the NCS with random packet dropout and networkinduced non-uniformly distributed time-varying delay in both from sensor to controller(S/C) and from controller to actuator(C/A).Based on the obtained NCS model,employing an observer-based fault detection filter as the residual generator,the addressed fault detection problem is converted into an auxiliary nonlinear H∞ control problem.Then,with the help of Lyapunov functional approach,a sufficient condition for the desired fault detection filter is constructed in terms of certain linear matrix inequalities,which depend on not only the delay interval but also the delay interval occurrence rate and successful packet communication rate.Especially,a trade-off phenomenon between the maximum allowable delay bound and successful data packet transmission rate is found,which is typically resulted from the limited bandwidth of communication networks.The effectiveness of the proposed method is demonstrated by a simulation example.     

基于SC-FDMA的可调公平度动态子载波分配算法

高速无线数据传输利用自适应的资源分配方式以对抗无线传输环境的不利影响。基于单载波频分复用系统提出一种最大平均容量动态子载波分配算法,并在此算法基础上引入公平系数,提出一种公平度可调的动态子载波分配算法,以实现系统分配公平性与总容量性能之间的权衡。仿真结果表明,最大平均容量算法在显著降低算法复杂度的同时,能获得与贪婪算法相近的系统总容量及误码率性能。可调公平度算法通过调整公平系数,能在较大范围内调整信道资源分配的公平度,满足不同传输质量需求,且不增加算法复杂度。     

Cyber攻击下韧性信息服务云环境能力评估

现代快速多变、不确定、Cyber对抗激励的战场环境对军事信息服务云环境的韧性能力提出了更高的要求,提出了一种Cyber攻击下韧性信息服务云环境能力评估方法。首先明确了韧性信息服务云环境的概念,分析了信息服务云环境韧性过程和要素,建立了Cyber攻击下云环境“四阶段”韧性过程模型;其次,从吸收扰动能力、恢复能力、适应能力3方面,建立了能力降级率、抗毁顽存时间、异常识别率、异常识别时间、能力恢复率、任务完成波动率等3类共15项韧性能力度量指标体系,建立了韧性能力指标评估计算模型。最后,以韧性信息服务云环境的指挥引导任务为案例,开展不同引导资源毁伤条件下指挥引导任务完成波动率的仿真实验,韧性评估结果可为提升韧性能力提供参考依据。     

Improved spectrum sharing algorithm based on feedback control information in cognitive radio networks

In order to avoid the system performance deterioration caused by the wireless fading channel and imperfect channel estimation in cognitive radio networks, the spectrum sharing problem with the consideration of feedback control information from the primary user is analyzed. An improved spectrum sharing algorithm based on the combination of the feedback control information and the optimization algorithm is proposed. The relaxation method is used to achieve the approximate spectrum sharing model, and the spectrum sharing strategy that satisfies the individual outage probability constraints can be obtained iteratively with the observed outage probability. Simulation results show that the proposed spectrum sharing algorithm can achieve the spectrum sharing strategy that satisfies the outage probability constraints and reduce the average outage probability without causing maximum transmission rate reduction of the secondary user.     

一个基于沟通函数的谣言传播仿真模型

人际谣言传播过程中人与人之间的沟通以及个体的记忆是谣言传播的主要因素。引入了个体对瑶言态度的不确定性、谣言的重要性和模糊性等参数建立了个体间的沟通函数,以此力基础实现了一介基于有限记忆的人际谣言传播的Agent仿真模型。仿真结果表明：谣言内容的重要性和模糊性、人际间的信任程度以及个体传播谣言的倾向概率以及个体基于有限记忆的态度选择是形成谣言及传播的重要因素。此结果能够与社会学、传播学对谣言形成与传播的研究结果相印证,反映了模型的合理性和有效性。