μC/OS-Ⅱ的多任务系统在SOPC中的硬件实现

本人在教学及科研实验中,对基于uC／OS～II的多任务系统在SOPC中的设计总结出了具体实现方法。经过实践验证,该方法简单、可靠,值得推广。     

EtherCAT网络数据采集系统的设计与实现

针对很多领域中数据采集量大、数据采集点分布广、间距长等问题设计了一种基于EtherCAT工业以太网的网络数据采集系统;简介了EtherCAT网络通信原理和结构,详细阐述了系统的硬件设计:以PIC单片机为主控制器,采用一片AD转换芯片并配合数个模拟量多路开关实现多路数据采集,并完成了EtherCAT主站程序、从站应用程序的设计;最后,对采集系统进行了实验验证,实验结果证实了该网络数据采集系统的实用性和可靠性。     

基于网卡的某型声呐目标模拟系统的设计

针对某型声呐目标模拟器是利用PCI总线进行上位机和下位机之间的通信,而随着移动PC和网络技术的发展,网络化的数据传输是未来数据传输的发展趋势,采用网卡芯片W5300开发了一种以太网接口系统;该系统由TMS320F2812DSP控制网络芯片W5300,给出了以太网接口的硬件设计原理、网络芯片的初始化及网络芯片数据的接收和发送控制三部分并介绍了网络驱动程序的设计;实践表明该接口稳定实现了上位机和下位机之间的网络通讯。     

一种基于多级检测的军装图片识别算法研究

为了在互联网上对军装图片进行过滤,我们设计了一种基于多级检测的军装图片识别框架,并在该框架下对其中的关键技术进行了深入的分析,就人脸快速检测技术、颜色纹理处理、区域形态学处理、基于支持向量机分类识别领花物件等进行了研究。实验表明,该算法在检测效率和精度方面能够满足实际应用的需要,可高效地对网络上传的军装图片进行高速过滤,该算法还可以解决其它类似的服装检测的问题。     

Swarm intelligence-based extremum seeking control

This paper proposes an extremum seeking control (ESC) scheme based on particle swarm optimization (PSO). In the proposed scheme, the controller steers the system states to the optimal point based on the measurement, and the explicit form of the performance function is not needed. By measuring the performance function value online, a sequence, generated by PSO algorithm, guides the regulator that drives the state of system approaching to the set point that optimizes the performance. We also propose an algorithm that first reshuffles the sequence, and then inserts intermediate states into the sequence, in order to reduce the regulator gain and oscillation induced by population-based stochastic searching algorithms. The convergence of the scheme is guaranteed by the PSO algorithm and state regulation. Simulation examples demonstrate the effectiveness and robustness of the proposed scheme.     

基于证据理论数据融合的双效水印

提出一种新的基于证据理论的数据融合的双效水印算法.首先应用水印公式构造特殊的水印嵌入后条件,根据嵌入系数之间的定性分析提取鲁棒水印;利用嵌入系数之间的定量分析能提取脆弱水印,并能准确定位篡改的区域.其次在嵌入过程中还使用纠错码对水印信息进行调和,把水印重复嵌入到图像信息的不同位置,以便利用纠错码的辅助信息来估计出提取的...     

Development of adaptive mesh refinement scheme for engine spray simulations

Spray modeling is a critical component to engine combustion and emissions simulations. Accurate spray modeling often requires a fine computational mesh for better numerical resolutions. However, computations with a fine mesh will require extensive computer time. This study developed a methodology that uses a locally refined mesh in the spray region. The fine mesh virtually moves with the liquid spray. Such adaptive mesh refinement can enable greater resolution of the liquid-gas interaction while incurring only a small increase in the total number of computational cells. The present study uses an h-refinement adaptive method. A face-based approach is used for the inter-level boundary condition. The prolongation and restriction procedure preserves conservation of properties in performing grid refinement/coarsening. The refinement criterion is based on the total mass of liquid drops and fuel vapor in each cell. The efficiency and accuracy of the present adaptive mesh refinement scheme is described in the paper. Results show that the present scheme can achieve the same level of accuracy in modeling sprays with significantly lower computational cost as compared to a uniformly fine mesh.     

A schema and ontology-aided intelligent information integration

The research issues of intelligent information integration have become ubiquitous and critically important in e-business (EB) with the increasing dependence on Internet/Intranet and information technology (IT). Accessing the intelligent information sources separately without integration may lead to the chaos of information requested. It is also not cost-effective in EB settings. A common general way to deal with heterogeneity problems in traditional III is to create a common data model. The eXtensible Markup Language (XML) has been the standard data document format for exchanging information on the Web. XML only deals with the structural heterogeneity; it can barely handle the semantic heterogeneity. Ontologies are regarded as an important and natural means to represent the implicit semantics and relationships in the real world. And they are used to assist to reach semantic interoperability in III in this research. In this paper, we provide a generic construct orientation no ad hoc method to generate the global schema to enable the web-based alternative to traditional III. We provide a wiser query method over multiple intelligent information sources by applying global-as-view (GAV) and local-as-view (LAV) approach with the use of ontology to enhance both structural and semantic interoperability of the underlying intelligent information sources. We construct a prototype implementing the method to provide a proof on the validity and feasibility.     

Selection of the implant thread pitch for optimal biomechanical properties: A three-dimensional finite element analysis

In this paper, effects of the implant thread pitch on the maximum Von Mises stresses were evaluated in jaw bones and implant–abutment complex by a finite element method. The thread pitch ranged from 0.5 mm to 1.6 mm. Results suggested that under axial load, the maximum equivalent stresses in cortical bone, cancellous bone and implant–abutment complex decreased by 6.7%, 55.2% and 22.3%, respectively with the variation of thread pitch; and under buccolingual load, 2.7%, 22.4% and 13.0%, respectively. When thread pitch exceeded 0.8 mm, minimum stresses were obtained. Data indicated that cancellous bone was more sensitive to thread pitch than cortical bone did; thread pitch played a great role in protecting dental implant under axial load than under buccolingual load; and thread pitch exceeding 0.8 mm were optimal selection for a screwed implant by biomechanical consideration.