3COM交换机技术及应用

本文介绍了3COM Superstack ⅡSwitch 3300 的主要特性及其在局域网中的实际应用，评述了冗余网络的构造等问题。     

高清晰度电视样机控制子系统的实现

本文提出了基于微处理器AT89C55的国家高清晰度电视样机控制子系统的总体设计方案和软硬件实现方法。目前，该控制系统己顺利完成，并参与北京、上海两地的功能样机测试。     

AutoCAD图形的打印输出技巧

针对AutoCAD使用者出图时所遇到的问题,提供了两种不同的解决方法.     

MPC850中复位逻辑和CPM协议切换的CPLD实现

介绍了用CPLD辅助设计方法在嵌入式系统中进行MPU复杂逻辑功能设计的总体方案。给出了通过对XC5144中复用控制寄存器进行配置以实现MPU复位逻辑和CPM协议切换的实现方案和设计要点。     

Water quality surveys: A statistical method based on determinism, quantiles and the binomial distribution

A statistical method for surveying water quality and analysing the results in terms of quantiles is described. The value of a water quality variable in a grab-sample is taken as a deterministic function of the temporal and spatial coordinates of the sampling point. Quantiles can then be defined for any specified region in time and space as unique, fixed values, and randomly located grab-samples may be used to estimate them for the purposes of describing or regulating water quality. Robust statistical inferences are possible using the binomial distribution. Properties of the quantiles, confidence limits, comparisons with fixed values or between regions, assessment of trends, simultaneous inferences and estimation of sample sizes are discussed. Two examples of water quality surveys, one of Port Phillip Bay, the other of the Maribyrnong River, Victoria, are used to illustrate the theory, paying particular attention to practical problems which arose. The proposed method is compared with others based on stochastic models, and is claimed to be simpler and more reliable.     

Spouted bed drying of cork stoppers

The spouted bed is commonly used to dry granular particles as it displays some special characteristics which render it capable of performing cyclic operations, with particles that are very difficult to fluidize under a different type of bed.Information on the characteristic drying rates of cork stoppers is still very limited in the technical and scientific literature, and until now no published data was found on the spouted bed drying of cork stoppers.The characterization of the drying performance of Port wine cork stoppers was carried out in a laboratory scale spouted bed. Characteristic drying curves were determined with 29 mm × 21 mm cork stoppers under several operating conditions. Values for the effective diffusivity were obtained in the range of 1.36 × 10⁻⁹ to 4.44 × 10⁻⁹ m²/s, with the temperature dependence represented by an Arrhenius-type relationship. The activation energy obtained was 28.72 kJ/mol.     

计算机网络安全扫描技术研究

随着互联网技术的发展,网络安全问题日益突出。作为一种主动防御手段,网络安全扫描技术在保护网络安全方面发挥着越来越大的作用。本文主要对主机探测,端口扫描,操作系统探测以及漏洞扫描等四种主要的网络安全扫描技术做了研究。     

MicroPort: A general simulation platform for seaport container terminals

Seaport container terminals are essential nodes in sea cargo transportation networks. As such, the operational efficiency of container terminals in handling containers passing through them plays a critical role in a globalized world economy. Many models and algorithms have been developed to address various decision problems in container terminals to help improve operational efficiency. These decision support tools are usually used separately for specific purposes. However, the problems they are trying to tackle are often interrelated. Therefore, in this regard, an evaluation tool which can capture as many operational conditions as possible for different decision problems is necessary. This paper introduces a general simulation platform, named MicroPort, which aims to provide an integrated and flexible modeling system for evaluating the operational capability and efficiency of different designs of seaport container terminals. The software structure of MicroPort comprises three programming layers: (1) the Functions layer; (2) the Applications layer; and (3) the Extensions layer. Different layers are bound by Application Programming Interfaces (APIs). Basic functions built in the Functions layer support the Applications layer in which major operation processes can be modeled by an agent-based method. External modules and decision support tools in the Extensions layer then use APIs to adjust the system to produce suitable simulation models for specific purposes.     

宁波港口口岸物联网现状分析与策略研究

港口口岸作为现代综合物流的中心,在推动经济发展的过程中发挥着越来越重要的作用,而物联网技术的应用为港口口岸的发展注入了新的活力,提供了新的解决方案。为加快宁波港口口岸现代化港口建设的需要,宁波港已启动了物联网应用项目的研究和建设工作。首先介绍宁波港口口岸物联网发展的现状和宁波在港口口岸物联网建设中的优势,然后分析了其在物联网建设中需要解决的一些瓶颈,并据此提出了宁波港口口岸物联网建设的具体策略建议。     

校园网网络计费相关的网络管理问题研究

网络流量计费是一种常见的网络管理手段。网络计费中经常遇到对流量统计结果的质疑、IP地址抢夺和账号被盗等三类问题。针对上述三类问题,通过网络管理的手段给出了分别的解决方案。