锻压机械打击力系统的计算机模拟

在试验的基础上建立了打击力测量的二阶动力学模型，不仅考虑了测力传感器的动态特性，而且考虑了被测机械系统的动态特性，并且上机进行了计算机模拟试验，探讨了打击力测量中存在的问题。     

分布式网络测量中测量节点的智能选择算法

大规模网络结构复杂,需要有针对性的网络监测方法。测量节点的自动选择必须在测量代价和覆盖范围之间进行权衡。合理地测量节点选择,能在获取全网性能状况的同时,有效减少测量给待测网络带来的带宽占用和软硬件资源消耗的影响。以最小化测量节点数量为目标,选择蚁群算法作为测量节点自动选择的基本算法,并通过对基本算法进行改进和创新,可形成一种针对分布式网络测量的测量节点智能选择算法。     

A Measurement‐Based Approach for Designing Fixed‐Order Controllers for Unknown Closed‐Loop Architecture

This paper presents a new technique to design fixed‐structure controllers for linear unknown systems using a set of measurements. In model‐based approaches, the measured data are used to identify a model of the plant for which a suitable controller can be designed. Due to the fact that real processes cannot be described perfectly by mathematical models, designing controllers using such models to guarantee some desired closed‐loop performance is a challenging task. Hence, a possible alternative to model‐based methods is to directly utilize the measured data in the design process. We propose an approach to designing structured controllers using a set of closed‐loop frequency‐domain data. The principle of such an approach is based on computing the parameters of a fixed‐order controller for which the closed‐loop frequency response fits a desired frequency response that describes some desired performance indices. This problem is formulated as an error minimization problem, which can be solved to find suitable values of the controller parameters. The main feature of the proposed control methodology is that it can be applied to stable and unstable plants. Additionally, the design process depends on a pre‐selected controller structure, which allows for the selection of low‐order controllers. An application of the proposed method to a DC servomotor system is presented to experimentally validate and demonstrate its efficacy.     

固定脉宽频率的自动化测试系统研究

论文的目的是实现电压频率转换电路的自动化测试。介绍了测频方法的原理和与计数法的比较,测试系统的软硬件组成和实现方法,并对实现的结果进行了说明。     

基于WinPcap的网络数据包监测系统

网络数据包监测是网络安全领域一个很重要的环节,设计网络监测系统是网络安全管理的起点。本文引入了WinPcap工具,分析了基于WinPcap的网络监测系统的设计框架,说明了数据包在程序内部的处理流程,描述了程序应用模块的设计过程,最后给出了系统运行情况并总结了其性能。     

Extraction Of Feature Lines On Surface Meshes Based On Discrete Morse Theory

We present an approach for extracting extremal feature lines of scalar indicators on surface meshes, based on discrete Morse Theory. By computing initial Morse‐Smale complexes of the scalar indicators of the mesh, we obtain a candidate set of extremal feature lines of the surface. A hierarchy of Morse‐Smale complexes is computed by prioritizing feature lines according to a novel criterion and applying a cancellation procedure that allows us to select the most significant lines. Given the scalar indicators on the vertices of the mesh, the presented feature line extraction scheme is interpolation free and needs no derivative estimates. The technique is insensitive to noise and depends only on one parameter: the feature significance. We use the technique to extract surface features yielding impressive, non photorealistic images.     

Performance analysis challenges and framework for high-performance reconfigurable computing

Reconfigurable computing (RC) applications employing both microprocessors and FPGAs have potential for large speedup when compared with traditional (software) parallel applications. However, this potential is marred by the additional complexity of these dual-paradigm systems, making it difficult to identify performance bottlenecks and achieve desired performance. Performance analysis concepts and tools are well researched and widely available for traditional parallel applications but are lacking in RC, despite being of great importance due to the applications’ increased complexity. In this paper, we explore challenges and present new techniques in automated instrumentation, runtime measurement, and visualization of RC application behavior. We also present ideas for integration with conventional performance analysis tools to create a unified tool for RC applications as well as our initial framework for FPGA instrumentation and measurement. Results from a case study are provided using a prototype of this new tool.     

低产井产量计量方法探讨

大庆油田已进人后续开发阶段,低产井数量在逐年增加,其产量的准确计量成了亟待解决的问题.现有的低产井产量计量还是采用与高产井相同的计量间分离器量油方式进行.由于低产井自身的特点,分离器量油方式不能如实反映其产能.对两种量油方式进行对比研究,通过具体应用实例表明,翻斗流量计计量低产井产量效果较好.     

基于MC9S12NE64的以太网测控系统的设计

嵌入式测控系统是当前工业自动化测控应用领域研究的热点之一。本文利用Freescale公司的MC9S12NE64MCU,运用其内部10位A/D模块,进行数据采集,并通过其集成的以太网网络模块实现了数据上传和远程控制。     

基于直方图相似度度量的中央空调风管附尘度检测

对于主从控制中央空调清洁机器人,操作人员依据视频很容易就可判断出风管是否清扫干净。在机器人自主清洗中央空调风管时,为了能够使机器人识别管道内灰尘附着程度,文章采用了直方图相似度作为清洁机器人自动判断管道附尘度和清洁与否的标准。文章给出了相关的原理和算法,并进行了试验验证,结果表明该方法具有快速性、实时性和准确性等特点。