基于云环境下一种小文件传输策略研究

基于互联网的文件传输策略将直接影响到文件传输效率和网络资源的使用效率,这一情况在各种资源集中的云计算环境表现得更为明显,特别是当传输大量小文件时尤为突出。针对这种现状,提出了一种基于打包策略的文件传输策略,给出了文件包优化处理机制,基于该策略,文件传输之前对小文件进行打包处理,然后进行传输,在接收端收到文件时首先进行解包再进行存储,从而减小传输过程中大量的IO操作,提升文件传输效率。大量的实验表明了本文所提策略的正确性,能够极大地提升云环境下小文件的传输效率,提高云资源的利用率。     

A study of optimal viewing distance in a parallax barrier 3D display

The optimal viewing distance was proposed as a parameter for designing a parallax barrier 3D display. It can be designed based on simple geometric method and by considering the pitches of image display pixels and parallax barrier, or even including the aperture ratios of the image display pixels and parallax barrier. It can be analyzed by using ray tracing method. By considering the optical refraction index of the cover glass, the angular behavior of the system becomes more realistic; however, the geometric method is difficult to be used. We propose a revised method for estimating the view distance and angular behavior. In this paper, we have demonstrated a designated eye position (DEP) for each view and shown that multiple DEPs make a circular curve around the center of the display. We prove the new concept by comparing the optical ray tracing calculations and optical measurement.     

Ergonomic Analysis of Head‐Mounted Night Vision Goggle Systems in Simulated Ground Operations

This study compared the mounting time and strain on the head‐neck while using an old model (forehead and cheek supported) and a new model (head harness supported) of head‐mounted night vision goggle systems in the postures of standing, sitting, and lying prone. The results showed that effectively reducing the mounting time was attributed to the ease and less time required for length adjustments of the head harness in the new model. The novel device received higher positive subjective ratings for convenience and comfort while wearing than did the old model. Although the weight of the new model was decreased to 0.794 kg and the length was reduced to 0.155 m, the loads on the head‐neck complex remained high. These findings suggest that a rifle should be fitted with the night vision goggle or handheld model to decrease neck‐shoulder workload if the prone position is the most frequent and important posture for soldiers. © 2011 Wiley Periodicals, Inc.     

乌江水电开发环境保护工作的探索与实践

乌江是目前我国按规划实施开发较为充分的典型河流之一.乌江水电开发环境保护工作见证了我国经济建设由注重经济效益向协调环境效益和社会效益实现可持续发展的转变,见证了我国水电开发环境保护工作逐步认识、探索实践与发展完善的过程.本文回顾了乌江水电开发环境保护工作的历程,介绍了乌江水电开发环境保护典型措施及工作经验,提出了当前水...     

新余钢铁厂三期板坯连铸机系统分析

本系统分析建立在理论设计和实际应用的基础上总结的,其系统构成有很强的针对性,设计思想在其他行业中也可用到。本文比较详细的叙述了连铸系统的工艺流程;并且由于系统本身的扩展性较强,系统的适应性也比较强。     

基于802.11e EDCA的无线网络传输性能仿真与分析

首先从理论上对比分析了IEEE 802.11 DCF和IEEE 802.11e EDCA这两种MAC接入机制;然后运用NS2网络模拟软件,仿真网络中视频、FTP和背景流在不同MAC协议网络中的性能表现,证实了IEEE 802.11e EDCA能提供QoS支持,提升无线网络传输性能。     

Learning to Locate Informative Features for Visual Identification

Object identification is a specialized type of recognition in which the category (e.g. cars) is known and the goal is to recognize an object’s exact identity (e.g. Bob’s BMW). Two special challenges characterize object identification. First, inter-object variation is often small (many cars look alike) and may be dwarfed by illumination or pose changes. Second, there may be many different instances of the category but few or just one positive “training” examples per object instance. Because variation among object instances may be small, a solution must locate possibly subtle object-specific salient features, like a door handle, while avoiding distracting ones such as specular highlights. With just one training example per object instance, however, standard modeling and feature selection techniques cannot be used. We describe an on-line algorithm that takes one image from a known category and builds an efficient “same” versus “different” classification cascade by predicting the most discriminative features for that object instance. Our method not only estimates the saliency and scoring function for each candidate feature, but also models the dependency between features, building an ordered sequence of discriminative features specific to the given image. Learned stopping thresholds make the identifier very efficient. To make this possible, category-specific characteristics are learned automatically in an off-line training procedure from labeled image pairs of the category. Our method, using the same algorithm for both cars and faces, outperforms a wide variety of other methods.     

应用统计过程控制监控软件测试过程

统计过程控制(SPC)是通过使用控制图来制定过程决策和预测过程行为的一种质量控制方法.SPC的方法用于软件过程,可以通过描述过程行为来监控过程的稳定性.讨论了将SPC应用于软件测试过程,针对测试过程中所度量的不同分布形式的数据而采用不同计算方式应用SPC的控制图,然后根据控制图判断测试过程是否稳定,并分析可能存在的可归属原因.     

图书电子商务网站的设计与实现

阐述基于ASP.NET技术构建一个实现网上购物的图书电子商务网站,并详细分析了系统的功能需求,及主要功能模块的设计与实现方法。该系统将Web技术和数据库技术很好地融合在一起,使数据库成为Web的重要组成部分,实现了数据库技术和网络技术的有机结合。