时滞区间静态神经网络的全局鲁棒稳定性

应用Lyapunov泛函方法和拓扑度理论研究了时滞区间静态神经网络的全局鲁棒稳定性,给出了一些实用的判据。     

基于改进边际优化的离散变量优化设计算法

针对传统离散变量优化方法存在的目标函数测算次数多、收敛性不佳等问题,借鉴边际优化理论和模式搜索算法,设计了一种基于改进边际优化的离散变量优化设计算法.借鉴边际效用优化原理,通过引入周围单位步长空间的概念,在初始点选择、边际增量设计、禁忌搜索策略等方面进行了改进,并设计了变异操作以跳出局部最优.实例分析表明,所提算法能够...     

ZIP回归模型的局部影响诊断

基于EM算法和完全数据对数似然的条件期望,分别研究了ZIP回归模型在加权扰动、解释变量扰动和响应变量扰动下的局部影响诊断问题,得到了相应的诊断统计量．最后通过一个实例说明诊断统计量的有效性。     

局部精细点的结构及其应用

在本文中,我们主要研究了局部精细点的结构,并讨论了其对抽象等周问题的应用.     

改进的遗传局部搜索算法在漏磁逆问题中的应用研究

通过将模拟退火技术加到遗传局部搜索算法(GLSA)的扰动过程中,提出一种改进的遗传局部搜索算法(IGLSA)及基于IGLSA的逆算法,用于从漏磁信号中重构二维缺陷.该算法中,径向基函数神经网络(RBFNN)用作前向模型,IGLSA用于求解逆问题中的优化问题.实验将该逆算法分别与基于规范遗传算法(CGA)的逆算法和基于GLSA的逆算法进行了比较,结果表明基于IGLSA的逆算法更精确,并且对噪声具有鲁棒性.     

A new method for uniform local heating deep in body using ultrasound phased-array system

A new method for targeted heating of deep tissue was developed by using an ultrasound phased-array system which can generate various multiple foci patterns by electronically changing its amplitude or phase pattern. This method involves using a technique of combining switching and rotating of multiple foci patterns to create a uniform temperature over tissue volumes in various size. Using this method, the target tissue deep in the body can be heated to a specified temperature, which gives conditions for thermo-sensitive liposomes release. A simulation study for a 108-element, spherically sectioned array was performed to determine an optimal heating scheme from a set of multiple focus fields which were produced by inputting different combinations of phases and amplitudes. Comparisons of a static multiple foci field, the switched fields and the switched-rotated fields indicated that the technique of combining switching and rotating of multiple foci patterns has advantages of both lowering the peak temperature and evening the temperature distribution. The simulation results also show that the therapeutic heating zones in various size employing the combined method. These results offer significant data for designing thermotherapy equipment for tumor-specific drug release with thermo-sensitive liposomes.     

A novel QoS supported cooperative diversity algorithm for IEEE 802.11 WLAN

A new cooperative diversity algorithm with quality of service （QoS） awareness for wireless local area network （WLAN） is proposed. According to this protocol, cooperation is invoked only if a direct transmission cannot meet user-specific QoS requirements. If cooperation is implemented, partner choice depends on who can achieve the minimum data rate required to have a successful transmission. The closed-form expressions for the system throughput and the power consumption are provided. Theoretical analysis and simulation results indicate that the QoS-aware cooperative scheme can significantly improve the system performance in terms of throughput and energy efficiency by avoiding negative effect of unconditional cooperation.     

强孤立子模

在孤立子模的基础上给出强孤立子模的概念并讨论强孤立子模的一些性质,并证明R-模M的加补子模N是强孤立子模当且仅当N的任意真子模被包含在N的极大子模中.     

基于X-10协议的远程家居照明控制系统

介绍了基于X-10协议及电力线载波传输的远程家居照明控制系统的设计。对于系统的硬件部分,采用单片机作为收发端控制器,以较为简洁的电路完成交流电的过零点检测。在接收装置的输出端利用继电器控制灯的开关或可控硅控制灯光的明暗调节。软件部分着重论述了基于X-10协议的通信协议和控制信号的程序实现。对系统可能存在的干扰问题进行了分析,提出了具体的抗干扰措施。     

轻型折叠落地四坡野营房屋表面风压分布分析

为了研究轻型折叠落地四坡野营房屋在风作用下表面风压分布特性,基于计算流体动力学和大气边界层基本理论,运用计算流体力学软件Fluent,参考现场实测和风洞试验结果,对落地四坡野营房屋进行数值模拟基础性研究,确定网格划分方式、网格数量及湍流模型等技术及基本参数。在此基础上:以风向角和落地坡角为参数,进行了24种工况下落地四坡房屋表面风压分布的数值计算,得到房屋表面风压分布特性及风荷载体型系数;用影响建筑气动外形的表面各区体型系数为参数,以对建筑表面作用最小为目标进行体型优化,得到合理体形的建筑落地坡角为60°~72°(屋脊角为132°~140°)。研究结果可为落地四坡房屋的抗风设计及体型优化提供理论依据。