一种EW接收机信号处理系统的设计与实现方法

设计了一种基于FFT/IFFT、全FPGA实现、环形结构的电子战数字接收机信号处理系统,它由4片FPGA分别实现高速数据传输接口、FFT/IFFT运算及信号的时/频域检测。该系统可完成1～1024K点的FFT运算及1～64K点的IFFT运算,可检测出4个同时到达的脉冲雷达信号的脉冲描述字参数。系统中FPGA以分布式、多总线、并行、流水方式工作,当采用256K点的FFT变换、32K点的IFFT变换时,检测出4个信号的典型用时约20ms。     

Optimum design of a new VSS-NP chart with adjusting sampling inspection

The classical Shewhart NP control chart is used widely in industrial and service practice for the relative simplicity of handling attribute quality characteristics. However, the static strategies become less and less adequate for today's highly competitive industrial society because of their low efficiency to detect slight process changes promptly. To improve the capability of control charts, some adaptive schemes, such as variable sample size (VSS), variable sample interval (VSI), and variable control limits (VCL), have been extensively studied in the recent decade. In this paper, we propose a new VSS NP control chart with adjusting sampling inspection (called ASI-NP chart) and give the performance analysis using Markov chain. As the optimal model is related to an integer nonlinear program, genetic algorithms (GAs) are involved and Taguchi experiments are applied to configure the parameter of the GAs in numerical examples. The comparison study between classical NP chart and ASI-NP chart is conducted, and the result shows that ASI-NP chart's performance characteristics are significantly better than those of classical NP charts in all situations, especially, in processes with slight shift and high quality.     

Regulating a monopoly with universal service obligations: The role of flexible tariff schemes

This paper's purpose is to study the problem of a utility monopoly's regulator, which has a universal service goal that is binding, in the sense that there is no two-part tariff that can induce efficient consumption, self-finance the firm, and guarantee universal access at the same time.     

大型对数周期天线阵列伺服控制系统的设计与实现

为了对大型对数周期天线阵列进行伺服控制,实现天线阵列中单轴转台俯仰方向的运动控制,设计并实现了大型对数周期天线阵列伺服控制系统。系统的主控制单元通过CAN总线与天线阵列中各天线驱动控制单元通信。除主控制单元触摸屏外,PC上位机通过主控制单元配置扩展网络接口模块,可对天线阵列进行远程控制,无需专人值守;应急手持设备在主控制单元或CAN总线故障时,可单独控制天线阵列中任一天线运动。运行结果表明,本系统已在16个大型对数周期天线构成的阵列中使用,能单独控制某个天线、控制某几个(或所有)天线同时同向或异向转动,或通过角度设置使天线转动到确定的角度,位置精度达到0.1°,运行状态稳定良好,可靠性高。能够满足大型对数周期天线阵列的控制要求,可应用于大部分大型对数周期天线阵列,有较高的应用价值,能为大型天线阵列控制提供参考。     

外卡式PVDF压力传感器的设计

系统阐述了外卡式PVDF压力传感器的设计过程,主要分为原理设计,结构设计,材料的选择,频率响应、性能指标的选取等,此种外卡式PVDF传感器可应用于柴油机高压油管压力的不解体检测。     

大型灌区渠道编码标准的设计与应用

渠道编码是灌区信息化中一项重要的基础工作,在《中国河流名称代码》SL249-1999等标准中有很少一部分大型渠道的编码,而突出灌区特色的渠道编码在国内尚未见相关报道。本文介绍了一整套的灌区渠道编码标准方案,以及在该方案中研究的问题及解决方法。将该方案应用于四川省都江堰灌区,完成了《都江堰灌区渠道名称代码》,并以都江堰灌区内一部分较有代表性的渠系为例,对其进行编码以示范编码方法和过程。以期对全国其它灌区标准的编制俾有所益。     

架空线路大跨越水文气象设计的探讨

结合梧州500kV变电站──平浪220kV架空城路得江大跨越的设计,分析和探讨对架空线路大跨越影响技大的各种水文、气象因素及相应的设计途径。     

The desire for increased participation: The validation of a framework with two large New Zealand companies

The goal of the study was to validate a survey instrument which was designed to test a framework describing attitudes to participation. A postal questionnaire was used with a sample of employees of two large companies. The results indicated consistency between the survey instrument and the framework. The participative environment offered by each company, although different, was independent of job status. The degree of participation was related to job status and the participative environment. The overall desire for increased participation was relatively small and was moderated by the degree of actual participation and the participative environment.     

Dilemmas and opportunities of a new curriculum: Design and technology with Young Children

The article draws on the University of Leeds research project Technological Capability in Young Children. The research objectives were to identify and characterize capability in design and technology for children aged 5–11; to document features of progression in capability within the domains of graphicacy, evaluation skills and the handling of tools and equipment; and to identify and investigate factors which contribute to the development of a technological knowledge base in primary school classrooms. The research perspective relates to previous studies of contextual and developmental features of capability and the development of practical intelligence. Data sources include fieldnotes and video recordings of children working on tasks defined by their teachers as design and technology activities; interviews with the teachers and children about the outcomes of the activities; and contextual data such as availability of materials, resources, use of teacher time, and classroom organization.Analysis of classroom recordings, together with teacher and pupil interviews, revealed a learning environment which presented teachers with new dilemmas and children with opportunities to demonstrate previously unnoted capabilities and deficiencies, particularly in graphicacy, evaluation processes and the manipulation of tools. The findings are exemplified through analysis of critical incidents.     

一种便携式色谱工作站的设计

色谱法是从混合物中分离组分并进行分析测定的方法,是物理、化学分析不可缺少的重要方法。采用虚拟仪器设计了一种便携式的色谱工作站,利用NI公司USB-6211采集卡实现数据采集,通过小波滤波算法对采集的信号进行预处理,并完成了谱峰识别和定量计算。系统不仅利用了计算机运算能力强、精度高、运算速度快、存储量大的优点,而且还充分利用了虚拟仪器技术易于实现、简单的数据采集系统和功能强大的数据分析处理能力,大大简化了色谱系统采集及分析处理的难度。