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.     

一种在驱动轮打滑情况下爬壁机器人动力学建模方法

分析了轮式爬壁机器人(WWCR)在壁面作业容易发生打滑的原因,在建立其理想纯滚动假设条件下的动力学模型基础上,基于车辆动力学理论,引入单个驱动轮的动力学方程,提出了一种在驱动轮打滑情况下WWCR的动力学建模方法.仿真算例表明,吸盘吸附力和壁面附着系数对WWCR运动轨迹影响非常大;在复杂的壁面环境下,可通过对吸盘吸附力和驱动轮力矩的协调控制,合理调节轮子的打滑程度,获得尽可能大的附着系数,并弥补打滑造成的运动轨迹偏移,从而获得良好的壁面运动性能.该建模方法为WWCR在打滑情况下的运动控制和路径规划提供了理论研究基础.     

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.     

天波雷达对空探测任务下积累时间自适应优化设置研究

针对人工设置天波雷达相干积累时间存在盲目性,不能充分发挥雷达探测性能的问题,以空中目标探测为研究对象,提出了自适应积累时间设置优化方法.首先,分析了积累时间对天波超视距雷达探测性能的影响.其次,计算了影响相干积累时间的信号时宽和积累点数的最优值.然后,提出了自适应设置积累点数的方法.最后,通过实验证明了本文方法比人工方...     

模糊综合评判法及其在人才选拔中的应用

将模糊数学的理论方法应用于学生能力的综合评判中,提出了一种人才能力量化的评判方法.通过实例说明该方法的可行性,为人才招聘与人才选拔提供一种新的方法.     

有色金属大型壁板型材连续轧挤初探

利用自行设计改装的连续轧挤设备模拟大型壁板型材的成形.以橡皮泥作为模拟试验材料,在由二辊轧机改装得到的连续轧挤设备上进行试验,模拟了宽×厚为98 mm×1 mm的板材连续轧挤生产过程.橡皮泥模拟试验及连续轧挤的工程法力学分析证明,利用连续轧挤法制备大型壁板型材是可行的,对大型壁板型材的制备有一定的指导作用.     

PLC电梯模型设计的几点思考

从实践的角度出发,对基于PLC控制的电梯实物模型的硬件和软件设计进行可行性的改进。采用模块化和多分支选择结构等设计方法,使系统的硬件设计更适合实践性环节的需要,软件设计更具有灵活性、更易于扩展。