Ranking Pages by Topology and Popularity within Web Sites

We compare two link analysis ranking methods of web pages in a site. The first, called Site Rank, is an adaptation of PageRank to the granularity of a web site and the second, called Popularity Rank, is based on the frequencies of user clicks on the outlinks in a page that are captured by navigation sessions of users through the web site. We ran experiments on artificially created web sites of different sizes and on two real data sets, employing the relative entropy to compare the distributions of the two ranking methods. For the real data sets we also employ a nonparametric measure, called Spearman's footrule, which we use to compare the top-ten web pages ranked by the two methods. Our main result is that the distributions of the Popularity Rank and Site Rank are surprisingly close to each other, implying that the topology of a web site is very instrumental in guiding users through the site. Thus, in practice, the Site Rank provides a reasonable first order approximation of the aggregate behaviour of users within a web site given by the Popularity Rank.     

Modeling Microwave Vacuum Drying Kinetics and Moisture Diffusivity of Carrot Slices

Carrot slices of 3.5 mm thickness were dried in a laboratory microwave vacuum dryer at five different microwave power density levels of 2, 4.66, 7.33, 10, and 12.66 W/g and at three vacuum chamber pressure levels of 6.66, 19.98, and 33.3 kPa to 4-6% d.b. moisture content. Inside the dryer the sample holding plate was rotated with the speed of 4 rpm for uniform microwaves application. The drying rates were increased with the increase in microwave power density at all pressure levels and the Page model was found to be the most suitable model to predict the drying behavior of carrot slices at all process conditions. The Page model drying rate constant (k, min^-1) showed high correlation with microwave power density at constant pressure by a power law equation and showed a logarithmic relationship with the microwave power density and pressure. Similar to the drying rate constant, the average moisture diffusivity at constant pressure was found to be function of microwave power density by power law equation as well as was also dependent on the power density and pressure by a logarithmic relationship.     

S7-1200利用高速脉冲输出方式实现打印

本文介绍SIEMENS S7-1200利用高数脉冲（Pulse Train Output,PTO）功能与MCU进行通讯的方法,具体介绍其中的一个应用：用PTO实现S7-1200的字符打印输出。     

网络爬虫在网页信息提取中的应用研究

网络爬虫是为了实现网络资源下栽功能的程序,是搜索引擎最重要的构件。考虑到网络上信息的种类繁多,研究一种基于网络爬虫的网页信息提取技术,并给出相关的设计方案,对设计方案进行验证,结果表明设计的可行性。     

冷轧处理线卷取机带头定位精度的改进

针对采用带头与卷取机芯轴橡胶套筒定位区动态接触的传统自动定位技术控制效果不好而带来带头印缺陷的问题，对其产生原因进行了分析，这是因为不同规格、钢种带钢的工艺参数不同，带钢穿带过程中在传送辊上的打滑量不同，在传输通道上的下垂量不同，带头到达卷取机芯轴定位区时计算带头位置与实际带头位置存在不稳定的偏差，因此带头定位精度不稳定。为此，开发了双动态自动定位技术，穿带过程中预留了足够的带钢打滑及下垂富余量，且带头与定位区中心线在助卷皮带咬入口静止状态下接触，消除了影响带头定位精度的主要因素，带头定位精度能稳定在±15 mm的误差范围内。实际应用效果表明，该方法可行、实用。     

可定制数据采集技术的研究和实现

总结传统数据采集软件的设计方法和存在的弊端,分析研究不同数据采集任务的异同,提出可定制化的数据采集技术,并对页面设计、模型配置、页面生成、库表建立等进行设计和实现,改变传统的数据采集软件研制模式,提高数据采集工作效率。     

基于Delphi的“虚拟胶片打印系统”的技术实现

利用Delphi和VS这两种开发平台,结合Oracle数据库,实现胶片排版、胶片调整、虚拟打印,自助打印、系统管理等功能。重点介绍了系统开发过程中针对特殊问题采用的几种技术。目的是完成胶片的集中打印管理,胶片存储备份,减少开支。     

A comprehensive study on the droplet formation processes and its influencing factors of a tubular piezoelectric print head

Abstract

Various inks with different properties are widely used in the printed electronic industry. In order to obtain high quality inkjet printing, it is necessary to study the droplet formation process and its influencing factors comprehensively. Only in this way, the incentive conditions and liquid physical parameters of droplet ejection can be obtained and optimized. Firstly, the calculation model of the droplet ejection process is established for a tubular print head and the boundary conditions are set according to the driving characteristics. Secondly, the free surface flow is calculated in the simulation software and sequential pictures of the droplet formation processes are captured to validate the availability of the numerical algorithm. Finally, the droplet formation processes of the tubular piezoelectric print head are simulated under different incentive conditions, different viscosities and different surface tensions. Too small a driving energy is insufficient to cause the head to eject droplets. Excessive excitation energy will result in larger or multiple satellite droplets. Additionally, the thinning process of the liquid neck is examined carefully in this paper. Results show that surface tension and viscosity have a significant effect on the thinning speed of the liquid neck, but the effect is not as significant as previous studies.     

基于3D打印的定制脊柱侧弯矫形器设计制造与舒适度评价

针对青少年脊柱侧弯矫正问题,研制一款由3D打印制成的脊柱侧弯矫形器并做出舒适度评价.该方法依据色努矫形原理,建立脊柱侧弯矫形器三维模型,并考虑躯干约束对矫形器进行了有限元仿真分析和结构优化,最后进行模型的分块和3D打印,分析精度误差.依据模糊理论和层次分析法,建立了包括环境、材料、结构、运动4个方面的主观舒适度评价方法.结果表明:3D打印技术可实现定制脊柱侧弯矫形器的制造与生产,并在几何精度和穿戴舒适性上表现良好.     

基于Ajax请求会话超时处理的研究

B／S架构下,来自于浏览器的同步请求如果发生了会话超时,可以很容易的让页面跳转到超时页面,但现在的Web系统为了提高用户体验,大量使用了Ajax技术,请求变成了异步请求,使用原有的方法,页面无法去处理跳转。本文在JQuery和Ext框架下,提出一种处理异步请求会话超时的方法。