基于多层结构应用技术的研究

多层分布计算应用服务技术是目前数据库应用发展的潮流,文章讨论传统客户／服务器（二层）的应用存在的局限性及三层结构所要解决的问题,并对三层结构的优势及开发三层应用的工具加以论述。     

基于MIDAS分布式多层系统的容错技术

讨论了分布式多层系统的容错技术,研究了分布式系统的对象迁移技术,在MIDAS支持下给出了一个容错方法。     

Volatility Forecasting via MIDAS,HAR and their Combination: An Empirical Comparative Study for IBOVESPA

In this paper we compare several multi‐period volatility forecasting models, specifically from MIDAS and HAR families. We perform our comparisons in terms of out‐of‐sample volatility forecasting accuracy. We also consider combinations of the models' forecasts. Using intra‐daily returns of the BOVESPA index, we calculate volatility measures such as realized variance, realized power variation and realized bipower variation to be used as regressors in both models. Further, we use a nonparametric procedure for separately measuring the continuous sample path variation and the discontinuous jump part of the quadratic variation process. Thus MIDAS and HAR specifications with the continuous sample path and jump variability measures as separate regressors are estimated. Our results in terms of mean squared error suggest that regressors involving volatility measures which are robust to jumps (i.e. realized bipower variation and realized power variation) are better at forecasting future volatility. However, we find that, in general, the forecasts based on these regressors are not statistically different from those based on realized variance (the benchmark regressor). Moreover, we find that, in general, the relative forecasting performances of the three approaches (i.e. MIDAS, HAR and forecast combinations) are statistically equivalent. Copyright © 2014 John Wiley & Sons, Ltd.     

Forecasting Mixed‐Frequency Time Series with ECM‐MIDAS Models

This paper proposes a mixed‐frequency error correction model for possibly cointegrated non‐stationary time series sampled at different frequencies. We highlight the impact, in terms of model specification, of the choice of the particular high‐frequency explanatory variable to be included in the cointegrating relationship, which we call a dynamic mixed‐frequency cointegrating relationship. The forecasting performance of aggregated models and several mixed‐frequency regressions are compared in a set of Monte Carlo experiments. In particular, we look at both the unrestricted mixed‐frequency model and at a more parsimonious MIDAS regression. Whereas the existing literature has only investigated the potential improvements of the MIDAS framework for stationary time series, our study emphasizes the need to include the relevant cointegrating vectors in the non‐stationary case. Furthermore, it is illustrated that the choice of dynamic mixed‐frequency cointegrating relationship does not matter as long as the short‐run dynamics are adapted accordingly. Finally, the unrestricted model is shown to suffer from parameter proliferation for samples of relatively small size, whereas MIDAS forecasts are robust to over‐parameterization. We illustrate our results for the US inflation rate. Copyright © 2014 John Wiley & Sons, Ltd.     

一种EPC Gen2 RFID标签时钟校准方法（英文）

设计了一种对Gen2 RFID标签的振荡器产生的时钟信号进行校准的方法,以解决以下问题：因受到工艺偏差的影响,EPC Gen2 RFID标签的振荡器的时钟频率可能与设计时的标称值有偏差,导致标签不能满足协议的要求,或导致标签功耗过大性能下降.该方法设计了时钟校准命令的前导信号,命令代码和命令参数;并给出了读写器使用时钟...     

MIDAS及其在DELPHI中的实现

讨论了M IDAS的结构、特点及实现技术,分析了如何用Delph i实现基于M IDAS的多层结构和实现多层结构的步骤.     

Revision of the Mediterranean species of Harmothoe Kinberg, 1856 and Lagisca Malmgren, 1865 (Polychaeta: Polynoidae: Polynoinae) with descriptions of a new genus and a new species

Based on type material and additional specimens, the revision presented here comprises all Harmothoe and Lagisca species known to occur in the Mediterranean Sea. The following 16 Harmothoe species are considered to be valid and an identification key is provided; seven of them (marked by *) represent new records for the Mediterranean: Harmothoe antilopes McIntosh, 1876; H. areolata (Grube, 1860); *H. aspera (Hansen, 1879); H. extenuata (Grube, 1840); *H. fragilis Moore, 1910; H. fraserthomsoni McIntosh, 1897; *H. gilchristi Day, 1960; *H. goreensis Augener, 1918; H. imbricata (Linnaeus, 1767); H. impar (Johnston, 1839); *H. lagiscoides serrata Day, 1963; H. longisetis (Grube, 1863); *H. pagenstecheri Michaelsen, 1896; *H. pokoui Intes and Le Loeuff, 1975; H. spinifera (Ehlers, 1864); one new species, H. bellani, is described. Harmothoe notochaetosa Ló     

某无梁板桥基于活载产生裂缝仿真与实验研究

本文主要是研究某无梁板桥桥梁产生裂缝的原因,根据《公路桥涵设计通用规范》等相关规范的规定,应用无梁板桥的分析理论,通过MIDAS仿真分析软件建立无梁板桥有限元模型。借助于该桥在活荷载作用下的变形、最大弯矩等力学参数,从活载方面分析了该桥裂缝产生的原因,并提出了加固建议,为相关桥梁裂缝原因研究提供参考。     

艮岳与北宋的灭亡

艮岳是宋徽宗在位时期用20年时间在国都东京修建的一处胜景。宋徽宗不惜耗尽天下之财富，不惜把人民推向水深火热之中，来满足自己穷奢极欲的生活。然而，当艮岳筑成之时，北宋王朝也走向了灭亡。宋徽宗被俘掠至金国，受到历史无情的惩罚和嘲笑。     

张花高速澧水大桥索塔基础大体积混凝土温控

 结合张花高速澧水大桥索塔基础大体积混凝土施工,根据热传导和有限元基本原理,应用MIDAS软件建立了澧水大桥索塔基础大体积混凝土温控计算模型.根据计算结果确定了温控方案,对大体积混凝土施工全过程进行实时温度监测,实现了大体积混凝土温度控制的信息化施工,为混凝土冷却水通水和保温保湿养护等温控措施提供了依据.大体积混凝土浇注完成后,索塔基础未出现温度裂缝,达到了预期目标.工程实践表明本文采用的大体积混凝土温度控制方法和流程有效,可供桥梁索塔基础等大体积混凝土施工借鉴.