基于DSP的柑橘分级系统硬件设计

文章介绍了基于DSP的柑橘分级系统的硬件方案所使用的技术.成像系统将采集的图像信息通过视频编码、解码后输入DSP进行预处理,并提取特征值,与标称值进行比较,从而确定每个柑橘的质量级别,实现分级.     

A class of classification and regression methods by multiobjective programming

An extensive review for the recent developments of multiple criteria linear programming data mining models is provided in this paper. These researches, which include classification and regression methods, are introduced in a systematic way. Some applications of these methods to real-world problems are also involved in this paper. This paper is a summary and reference of multiple criteria linear programming methods that might be helpful for researchers and applications in data mining.     

Stability analysis of neutral systems with mixed delays

The stability of neutral systems with mixed delays is studied in this paper. A new discretized Lyapunov functional method is proposed. The method in this paper is less conservative than the existing ones and the results are very close to the analytical results. In addition, this method allows the coefficient matrix of the neutral term to have time-varying uncertainties.     

Stability analysis of neutral systems with distributed delays

The stability of neutral systems with distributed delays is investigated in this paper. A modified Lyapunov-Krasovskii functional is constructed to study this class of systems. The proposed stability criterion is discrete-, distributed- and neutral-delay-dependent. In addition, by this method one can study the case when the coefficient matrix of the neutral delay term is time-varying uncertain. The reduced conservatism is illustrated in a numerical example.     

Adaptive robust posture control of a parallel manipulator driven by pneumatic muscles

Rather severe parametric uncertainties and uncertain nonlinearities exist in the dynamic modeling of a parallel manipulator driven by pneumatic muscles. Those uncertainties not only come from the time-varying friction forces and the static force modeling errors of pneumatic muscles but also from the inherent complex nonlinearities and unknown disturbances of the parallel manipulator. In this paper, a discontinuous projection-based adaptive robust control strategy is adopted to compensate for both the parametric uncertainties and uncertain nonlinearities of a three-pneumatic-muscles-driven parallel manipulator to achieve precise posture trajectory tracking control. The resulting controller effectively handles the effects of various parameter variations and the hard-to-model nonlinearities such as the friction forces of the pneumatic muscles. Simulation and experimental results are obtained to illustrate the effectiveness of the proposed adaptive robust controller.     

基于单片机控制的等精度频率计设计制作

用D触发器控制两个计数器count1和count2的同步工作,以保证count1和count2计数时间的一致性;将count1和count2与单片机的定时器T0和T1相结合构成两个20位的高精度计数器,分别对标准频率脉中和被测频率脉中进行计数;利用单片机串行口完成输出显示.从而克服了传统测频原理的频率计的测量精度随被测信号频率的下降而降低的局限性,提高了频率测量的精度.     

基于效用公平的多用户下行OFDM系统机会调度

基于对单信道系统中效用公平机会调度的研究,提出了一种多用户下行OFDM多载波系统中的调度方案.该方案充分利用信道的时变和频率选择特性,由参数更新和调度决策两个模块组成:参数更新模块根据调度结果更新控制参数;调度决策模块根据所有用户的信道信息和参数更新模块输出的公平性控制参数决定该时隙每个用户使用哪些子载波.仿真结果表明,参数选取合适时,所提的简单调度方案能够在保证效用公平性的前提下,达到比复杂的Max-Min子裁波分配算法更好的系统性能.     

多小区MIMO系统中的一种主动式干扰抑制方案

针对多小区下行链路中的同频干扰问题,提出了一种新的主动式干扰抑制方案.该方案通过在各基站独立地采用预编码的方式来主动抑制本小区基站对其他相邻小区所产生的干扰.文中提出了两种实现算法:(1)迫零预编码,它可以获取和无同频干扰系统同样的性能;(2)基于干扰信道最大特征子信道的线性预编码,它能够有效地实现抑制干扰和提高本小区发遥自由度的折衷.仿真结果表明,本文方案提高了系统的性能和频谱效率.     

基于办公网络在线实验系统的实现

虚拟仪器技术的发展及应用,使远程实验办公成为可能。本文研究了基于办公网络的MatLab在线实验系统组建的多种技术方案,系统设计采用了Active X组件,COM组件等混合编程技术,服务器采用.NET框架、SQL数据库技术和网页制作技术,使先进的实验资源为办公网络中的所有用户所利用,满足办公环境下在线实验的需求。     

一种基于Web漏洞威胁模型的网站安全分析技术

网站日益受到黑客的青睐,针对Web应用程序的攻击事例屡见不鲜。如何全面、准确地分析网站面临的最大威胁成为专业信息安全公司和网站管理员的不可回避的难题。本论文借鉴攻击图的基本思想设计了漏洞威胁测试模型(VTTM),并以SQL注入漏洞为例对其进行建模,并利用两种算法分别计算了网站的最大威胁值及最优测试序列。