最佳取送车次数问题的改进

合理确定取送车作业次数有利于减少货车在站停留时间和相关的运营支出。通过对取送车作业过程和货物作业车在站停留时间的分析,以及对货物装卸时间进行合理调整,对一昼夜取送车最佳次数的确定进行改进,从而在原研究成果基础上对最佳取送次数的公式做相应修改,通过实例说明改进后更加符合实际情况。     

中国金融周期与横向关联:时空双维度相结合视角

宏观审慎政策关注各金融子市场在时间维度上的金融周期和空间维度上的横向关联。本文结合时间维度与空间维度视角,使用股票市场、货币市场、房地产市场以及信贷市场的数据,测算2001—2019年中国金融周期和横向关联的波动特征、作用关系与频域叠加机理。研究结果表明:时间维度金融周期与空间维度横向关联的波动趋势具有一致性。我国金融周期长度约为10.33年,横向关联波动周期的长度约为10.58年。从作用关系上看,首先,我国房地产周期达到波峰后,会对股票市场和信贷市场产生较强的溢出效应。随后,股市周期达到波峰后,会向房地产市场和信贷市场产生较强的溢出效应。最后,我国信贷市场接受股票市场和房地产市场溢出后,信贷周期会逐渐达到波峰。从频域叠加机理的角度看,我国金融子市场间横向关联的波动主要由中低频波段驱动,中低频波段横向关联的持续期在2个月以上。     

超高频电子标签射频模拟前端的设计与仿真

通过研究超高频段RFID电子标签的特性,对符合ISO18000-6B标准的超高频标签的射频模拟前端部分进行了研究,重点介绍了该标签的系统结构及工作原理,并给出了其射频模拟前端关键部分的设计与仿真。该超高频电子标签具有识别距离远、通信速度快、尺寸较小、可重复使用等优点,主要应用于生产、零售、物流、交通等各个行业。     

变频器在浮法玻璃生产线中的应用及其抗干扰的几个方法

主要介绍了变频器的使用方法,干扰的形成、来源、途径,防止干扰的对策及其在实际应用中几种有效的抗干扰措施。     

RFID技术在我国物流行业的应用分析

目前RFID（无线射频识别）技术已被越来越多企业关注,文章阐述了RFID技术应用于物流行业各领域的。优势,重点对RFID技术还无法得以广泛应用的原因进行了分析,最后提出了对我国物流业发展RFID技术的思考和美好愿望。     

Do market-concentrated airports propagate more delays than less concentrated ones? A case study of selected U.S. airports

Airport congestion and widespread passenger discontent with airlines' poor on-time performance have recently led the Federal government to reduce peak-time operations at large airports such as Chicago O'Hare and New York John F. Kennedy. This paper proposes a methodology to compute delay propagation based on the discrete Fourier transform (DFT) at a sample of ten U.S. airports in summer 2000, 2007 and 2008. The sampled airports are different in terms of size, location and index of concentration.In this research, a flight is considered to be late if it arrives more than fifteen minutes past its schedule. Delay propagation is defined as the hourly ratio of two amplitudes: the one of late arrivals at a sampled airport to that of late arrivals at the final destinations served from that same sampled airport. The purpose of this study is to determine whether delay propagation differs at market-concentrated airports from less concentrated ones. Based on nonparametric tests and proximity analysis, there is no clear evidence that market-concentrated airports are different from less concentrated ones in terms of propagated delays.     

一种新的频率规划方法

本文针对目前频率规划中存在的问题，提出了利用专家系统和改进遗传算法及分层技术等来克服手工频率规划过于烦琐和电子地图要求极高及频带紧张的障碍，从而在缺少准确电子地图的情况下，借助专家的经验和知识同时利用改进的优化算法亦能给出较准确的频率规划方案。同时提出了改进的模糊似然推理方法。此外我们开发了智能多层频率规划ＣＡＤ软件包，并给出仿真结果。     

Some empirical evidence on the ‘discouraged worker’ effect

This note produces empirical evidence on the existence of a significant ‘discouraged worker’ effect in US data–namely, on the tendency for groups of secondary workers to move in and out of the labor force with the business cycle, looking for jobs when these are available, while giving up job search during recessions — by focusing on the behavior of the ‘not in the labor force’ series, as well as of two of its segments (‘going to school’, and ‘keeping house’), at the business-cycle frequencies. Both in the aggregate, and for a number of age–sex groups, the series display a clear counter-cyclical pattern, thus lending support to the discouraged worker notion.     

Bayesian Premium Rating with Latent Structure

We propose a fully Bayesian approach to non-life risk premium rating, based on hierarchical models with latent variables for both claim frequency and claim size. Inference is based on the joint posterior distribution and is performed by Markov Chain Monte Carlo. Rather than plug-in point estimates of all unknown parameters, we take into account all sources of uncertainty simultaneously when the model is used to predict claims and estimate risk premiums. Several models are fitted to both a simulated dataset and a small portfolio regarding theft from cars. We show that interaction among latent variables can improve predictions significantly. We also investigate when interaction is not necessary. We compare our results with those obtained under a standard generalized linear model and show through numerical simulation that geographically located and spatially interacting latent variables can successfully compensate for missing covariates. However, when applied to the real portfolio data, the proposed models are not better than standard models due to the lack of spatial structure in the data.     

FRID技术在物流仓储管理中的应用

物流业发展迅速,采用自动化技术来提高效率,但有很多工作仍需要人工完成,容易出错。而无线射频识别技术(RFID)在仓库中作为信息传递的载体,可以有效避免人工输入可能出现的失误,大大提高工作效率。利用RFID无限射频技术并结合ABC库存管理法对货物的入库、出库、盘点进行自动化管理,实现仓储的自动化管理。