基带成形滤波器的FPGA实现

针对数字化基带成形滤波的信号处理特点，将截短的基带波形进行二维分解，得到成形滤波器的多相结构。通过对多相结构的分析，给出了一种较为精简实用的基于滤波器系数查询表模式的FPGA实现结构，该结构具有实现简单、占用资源少等特点。仿真结果表明，该结构完全可以达到实际应用的要求。     

Time Series Analysis of Repeated Surveys: The State–space Approach

Cross sectional estimates from repeated surveys form a time series { y_t }. These estimates can be viewed as the sum y _t = Y _t + e _t of two processes, { Y _t }, the population process and { e _t }, the survey error process. Serial correlations in the latter series are usually present, mainly due to sample overlap. Other sources of data such as censuses, administrative records and demographic population counts are also available. The state–space modelling approach to the analysis of repeated surveys allows combining information from different sources, incorporating benchmarking constraints in a natural way. Results from these methods seem to compare favourably with those from X-11-ARIMA in filtering out survey errors.     

椭圆半带滤波器及其在小波包谐波分析中的应用

小波包分解因为具有较高频谱分析的精度，在电力系统谐波检测中得到了广泛的应用．但其复杂的计算使它在实时的测量中受到了限制．现提出了将IIR椭圆半带滤波器应用于小波包谐波分析中的新方法，通过研究表明，该算法可以将复杂的计算减少到与快速傅立叶变换（FFT）同等数量级上．仿真和实验结果进一步表明了该算法的有效性．     

Time varying country risk: an assessment of alternative modelling techniques

Three different techniques for the estimation of a time-varying beta are investigated: a bivariate GARCH model, the Schwert and Seguin approach, and the Kalman filter method. These approaches are applied to a set of monthly Morgan Stanley country index data over the period 1970 to 1995 and their relative performances compared. In-sample forecast tests of the performance of each of these methods for generating conditional beta suggest that the GARCH-based estimates of risk generate the lowest forecast error although these are not necessarily significantly less than those generated by the other techniques considered.     

提高污水厂带式压滤机处理能力的途径

介绍了某污水处理厂污泥处理系统的组成和带式压滤机工作的特点,通过分析带式压滤机处理能力的影响因素,经过生产运行试验,提出了改变排泥、污泥缓冲池、带式压滤机运行过程的排泥法来降低进泥含水率,总结了改善滤带冲洗效果的方法和控制絮凝剂制配,提高了带式压滤机的处理能力,实践证明有较好的效果。     

Tourism expenditure patterns in China

Using China’s urban household survey data for 2002–2009, this study compares the impacts of the socio-economic and demographic characteristics of urban household expenditure on tourism in different age cohorts. The life cycle age profiles of group-tour and non-group tour expenditures are obtained by decomposing total household expenditure. The results show that the age profile of total tourism expenditure is hump-shaped, which conforms to consumers’ income discretionary expenditure cycles. The age profile of group-tour expenditure is hump-shaped whereas that of non-group tour expenditure is S-shaped, corresponding to the substitution of group and non-group tours as children grow older. The implications are discussed in the context of tourism marketing with a view to providing useful segmentation information for tourism decision makers.     

基于VAR 的我国预期通货膨胀率的估计问题研究

在当前影响物价变动的因素愈加广泛和复杂的背景下,如何准确把握未来通货膨胀预期走势进而有效调控通货膨胀至关重要。本文首先通过建立附加前瞻性政策变量的 VAR 预期模型, 根据 2002 年第一季度至 2014 年第三季度的通货膨胀率、实际利率和产出偏差的实际值与预期目 标值的偏差值季度数据,采用卡尔曼滤波递归算法得出我国的通货膨胀预期的估计结果。随后基 于理性预期理论对初步估计结果进行检验。研究结果表明,采用前三个月实际利率、实际通货膨 胀率的算术平均作为下期中国人民银行调控目标的预期值是较为符合我国情况的选择。     

新型小型化超宽上阻带双频带通滤波器的设计

本文使用并联短截线结构获得5.7GHZ的通带,再引入SIR谐振器结构,获得2.4GHZ的通带。SIR谐振器耦合作用到微带传输结构上,所以,两种谐振结构相互独立,能方便的调整两个通带的中心频点。此外,两种谐振结构在阻带上相互抑制,获得极宽的上阻带性能。本文在输入、输出端口附近又引入并联短截线,使得上阻带性能更加优异。最终测量结果和仿真结果吻合。     

纤维转盘滤池在污水处理厂深度处理中的应用

文章结合天津某污水处理厂升级改造工程的实例,介绍了一种先进的新型过滤技术--纤维转盘滤池的使用情况,对纤维转盘滤池的结构、运行状态、特点等均做了详细说明。     

Tourist market segmentation with linear and non-linear techniques

The need for in-depth knowledge of tourist market segments and the need to overcome the limitations of using linear techniques to analyse non-linear relationships requires a re-assessment of generally used approaches such as cluster analysis and multiple linear regression. The objectives of the research are (1) to consider the use of self-organising (SOM) neural networks for segmenting tourist markets and (2) to analyse the predictive ability of backpropagation (BP) neural networks for classifying tourists from follow-up surveys by using the output provided by a SOM neural network. The findings of the SOM neural network modelling indicate three natural clusters. In addition, the predictive ability of the BP neural network model appears to be superior to that of MLR static filter and logistic regression models. The BP neural network model developed for this application appears suitable for deployment (i.e. classification of tourists from follow-up surveys).