基于新算法的P码序列捕获处理器设计与实现

通常P码的捕获是利用C/A码来完成的。但是,考虑到实际的战场可用性,利用C/A码引导的P码捕获方式不再具有较好的可靠性。同时考虑到P码信号的特点,对P码信号进行直接、快速的相关捕获是首先要解决的问题。因此,在研究相应理论的基础上,对提出的新的P码直接捕获算法进行硬件设计,实现了P码序列捕获处理器。在实验室环境下对序列捕获处理器进行测试,结果验证序列捕获处理器可以有效捕获GPSP码信号。     

Multiple targets vector miss distance measurement accuracy based on 2-D assignment algorithms

An extension of 2-D assignment approach is proposed for measurement-to-target association for improving multiple targets vector miss distance measurement accuracy. When the multiple targets move so closely, the measurements can not be fully resolved due to finite resolution. The proposed method adopts an auction algorithm to compute the feasible measurement-to-target assignment with unresolved measurements for solving this 2-D assignment problem. Computer simulation results demonstrate the effectiveness and feasibility of this method.     

Risk reduction in a project portfolio

The positive impacts of managing projects as a portfolio are quantified by comparing the value of the integrated risk of a project portfolio and the aggregation of single project risks implemented separately. Firstly, the integrated risk is defined by proposing risky events based on set theory. Secondly, as projects interact with each other in a project portfolio, the integrated risk is evaluated by using a Bayesian network structure learning algorithm to construct an interdependent network of risks. Finally, the integrated risk of a practical case is assessed using this method, and the results show that the proposed method is an effective tool for calculating the extent of risk reduction of implementing a project portfolio and identifying the most risky project, so as to assist companies in making comprehensive decisions in the phase of portfolio selection and portfolio controlling.     

Spectral Properties and Positivity of Flows in Infinite Networks with Dynamic Boundary Control Nodes

In this paper we study transport processes on infinite networks with dynamic boundary control nodes. These flows can be modeled by operator semigroups on a suitable Banach space. Using functional analytical and graph theoretical methods, we investigate its spectral properties of the system and positivity of the semigroup under appropriate assumptions on the network.     

基于广义随机Petri网的城市道路公交优先建模与性能研究

针对当前城市道路网存在的交通拥堵问题,根据城市地面交通的特点和公交优先的原则,利用广义随机Petri网通过将变迁分为时间变迁和瞬时变迁,结合禁止弧和赋予各弧不同的优先权, 构建公交优先策略模型,为实施公交优先策略提供理论依据.     

Online blind source separation based on joint diagonalization

A now algorithm is proposed for joint diagonalization. With a modified objective function, the now algorithm not only excludes trivial and unbalanced solutions successfully, but is also easily optimized. In addition, with the new objective function, the proposed algorithm can work well in online blind source separation (BSS) for the first time, although this family of algorithms is always thought to be valid only in batch-mode BSS by far. Simulations show that it is a very competitive joint diagonalization algorithm.     

基于观测器的飞机除冰液温度鲁棒控制方法研究

对飞机除冰液温升模型的时变和延时特性进行了分析研究.采用Pade逼近对飞机除冰液加热系统的纯时延特性进行近似,将系统的时延问题转化为非时延问题进行处理.为克服由于飞机除冰作业过程中流量变化所造成的系统模型参数变化,采用基于滑模变结构的鲁棒控制方法对系统模型参数摄动进行补偿.为解决系统状态不可测问题,消除Pade逼近误差对出口温度的影响,采用状态观测器对系统的状态进行估计,并对Pade逼近模型输出误差进行补偿.利用系统不同流量下的试验温升曲线模型对设计的控制策略进行了仿真研究,仿真结果验证了所提出算法的有效性.     

异构网络中基于兴趣感知的聚类缓存策略

为应对移动流量的爆炸式增长,在异构网络中引入缓存成为目前的热点研究方向之一。目前缓存部署策略存在缓存命中率不高、缓存数据冗余度较高等问题,没有充分利用存储资源,直接影响网络的性能。针对以上问题,提出一种基于用户兴趣感知的虚拟聚类协作缓存部署策略来提高缓存系统性能。根据用户距离构造虚拟聚类,依据内容请求因子确定系统缓存内容,采用基站协作缓存以及用户间虚拟聚类方式共享缓存内容,以缓存命中率最大化为目标建立优化模型并通过贪婪算法求解。理论分析及仿真结果表明,在异构网络场景下,跟现有方法相比,所提方法在缓存命中率、系统平均传输时延等性能上均有明显提升。     

无线自组织通信中基于前导符号的定时同步

传统的基于自相关的和基于互相关的定时同步算法具有相关峰的旁瓣较宽或对载波频率偏移(carrier frequency offset, CFO)敏感的问题,均无法满足无线自组织通信系统对快速准确的定时同步的需求。针对这一问题,提出了一种新的基于改进互相关的定时同步算法,通过将一个长的相关器拆分为两个较短子相关器的乘积,使度量函数的主峰更加尖锐、次峰更低,理论分析了算法的抗频偏性和计算复杂度。对所提算法和传统互相关算法的蒙特卡罗仿真结果表明,在复杂度相当的前提下,所提算法在检测准确率上具有1.1 dB的性能增益,且对频偏的鲁棒性较好。     

学术团队与学科群系统核心竞争力的关系研究

把集群和核心竞争能力的概念借鉴到教育学领域，引出学科群系统及其核心竞争力，并对学科群及其系统进行解释，探讨影响学科群系统核心竞争力的因素。进而研究学术团队的开放度对团队创造能力的影响以及对学科群系统核心竞争力的影响。