实现GPRS数据传输新方法的研究

描述了在"863"农田墒情项目解决过程中提出的GPRS上网传输数据的新方法,总结了GPRS网络的体系结构.通过实例深入剖析了PPP协议的实现原理和帧格式,分析了协议中各种类型的包结构,简化了认证过程.并通过裁减PPP协议和UDP/IP协议,给出了详细可行的针对GPRS模块上网的UDP/IP包封装及解析的新方法,并且通过试验取得了良好的效果.     

GPRS网络应用系统中的协议转换

GPRS模块在当前远程监控过程中得到越来越广泛的应用,但在使用GRPS模块时存在数据不兼容性问题。本文介绍一种协议转换的解决方法,并实现了PPP协议、TCP/IP协议的一些基本特征,同时实现了在GPRS模块上的应用。     

Snoop在GPRS网络中性能的提高

仿真测试显示Snoop协议在GPRS网络中性能低下,文章测试分析了Snoop在GPRS网络中的性能,修改了Snoop协议的重传触发条件和实现机制,显著提高了Snoop在GPRS网络中的性能。     

一种串口与远程GPRS设备通信适配器的设计与开发

工业现场内置GPRS设备种类众多,技术人员需要分别使用各厂家的上位机软件对设备进行远程监控.为了解决这个不兼容问题,基于Modbus和Modbus TCP协议设计并实现了串口通讯软件与远程GPRS设备通信适配器.串口通讯软件将控制和数据采集的Modbus报文发送给适配器,适配器维护GPRS设备列表,将串口报文转为Mod...     

基于嵌入式Linux的无线自动拍照终端

在确定Linux+通用分组无线服务(GPRS)无线自动拍照终端总体设计方案的基础上,采用GPRS无线通信技术和计算机技术设计并实现无线自动拍照终端。采用AT91RM9200嵌入式微处理器、GPRS无线通信模块等电路设计无线自动拍照终端的硬件,构建嵌入式Linux操作系统平台,移植端对端协议(PPP),采用多进程开发应用程序,应用TCP/IP协议和PPP设计GPRS无线通信软件,并进行调试和实验。     

基于GPRS短信报警系统的设计研究

GPRS网络的数据交换优势在于图像传输能够通过点之间完成,除了图像传输之外,在远程目标监控、远程数据传输等等方面都得到了广泛的应用。在本文中,笔者从GPRS基础技术入手分析,简要阐述GPRS网络构成、协议模型、工作原理,在了解GPRS的基础内容之后,在VB开发的基础上,对GPRS短信报警系统进行设计研究,主要是对短信控制系统软件的收发实验,从两个方面进行重点介绍,一是窗体程序部分、一是模块程序部分。     

微控制器的GPRS无线上网

介绍一种在微控制器上实现PPP协议,并使其控制GPRS模块通过GPRS连入Internet的方法;介绍GPRS技术和GPRS模块的使用方法;重点介绍微控制器软件的层次结构和PPP协议的实现方法。     

基于GPRS短信报警系统的设计研究

GPRS网络的数据交换优势在于图像传输能够通过点之间完成,除了图像传输之外,在远程目标监控、远程数据传输等等方面都得到了广泛的应用。在本文中,笔者从GPRS基础技术入手分析,简要阐述GPRS网络构成、协议模型、工作原理,在了解GPRS的基础内容之后,在VB开发的基础上,对GPRS短信报警系统进行设计研究,主要是对短信控制系统软件的收发实验,从两个方面进行重点介绍,一是窗体程序部分、一是模块程序部分。     

GPRS网与Internet间数据传输方案的解析

文章分析了点对点协议,重点讨论了GPRS模块设置,介绍了通用无线分组业务（GPRS）无线方式接入互联网的方案,实现了GPRS网与Internet间的数据传输。该方案有效解决了采用传统有线方式进行工业现场数据采集监控所带来的局限,同时实现了软件和硬件、有线和无线的结合,从而达到了资源整合、优势互补。     

GPRS网络的远程监测系统

介绍了一基于GSM网络的GPRS网络通信技术实现远程数据传输，从而实现远程水位实时监控功能的系统。该系统的核心部分GPRS具有永远在线、快速登录、按量收费和自由切换等优点，保证了系统的稳定性，并且大大减少了系统的建设投资和运营费用。     

Hyperbolic regression analysis for kinetics, electrophoresis, ELISA, RIA, Bradford, Lowry, and other applications

Hyperbolic regression analysis is an effective method for fitting experimental data points obtained from a variety of experiments in molecular biology, including enzyme kinetics, agarose gel electrophoresis of DNA fragments, SDS-polyacrylamide gel electrophoresis of proteins, enzyme-linked immunosorbent assays (ELISA), radioimmunoassays (RIA), Bradford protein quantitation assays, Lowry protein assays, and other applications. Hyperbolic regression yields excellent fitted curves without the biases that are introduced by carrying out linear regression on double reciprocal coordinates, and it produces one simple equation, encompassing all the data points, that can be used easily in a pocket calculator to estimate the values of unknown samples from the known standards.     

Louis Kruh,Cryptologist, Editor,Activist

Abstract

The double transposition cipher was considered to be one of the most secure types of manual ciphers. It was extensively used in both World Wars and during the Cold War. In 1999, Otto Leiberich, the former head of the German federal office for information security, suggested that a double transposition challenge be published with specific parameters designed to ensure its security. Such a challenge was published by Klaus Schmeh in 2007. In November 2013, the authors solved the challenge using a ciphertext-only hill climbing attack. They also solved the challenge using a dictionary attack. In this article, they describe both methods, which are based on a “divide-and-conquer” approach. They additionally discuss the impact of their solutions with respect to the general security of the double transposition cipher.     

Electronic Markets, Hierarchies, Hubs, and Intermediaries

The impact of information technologies on organizations is difficult to predict, although critical for developing comprehensive organizational strategies. Much of the difficulty is traceable to the treatment of all information technologies as a single factor, when in fact different technologies may have drastically different impacts on the organization. Specifically, the distinction between two general classes of technologies, communication and information processing technologies, is studied. An analytical model is developed to show that these two classes of technologies have exactly the opposite impacts on the organization. Moreover, the impact also depends on the organization, and its existing structure. Communication intensive and processing intensive organizational structures are distinguished and they are shown to be impacted differently by information technologies. An analytical framework is developed to show a continuum of organizational structures, depending on their relative communication and processing intensity, and the effect of various technologies is shown to be to move the organization along that continuum. Communication and information processing technologies are shown to move the organization in opposing directions. Finally, the analytical framework is shown to be robust and valid under a wide variety of conditions, covering most real life organizations.     

Pointcuts, advice, refinements, and collaborations: similarities, differences, and synergies

Aspect-oriented programming (AOP) is a novel programming paradigm that aims at modularizing complex software. It embraces several mechanisms including (1) pointcuts and advice as well as (2) refinements and collaborations. Though all these mechanisms deal with crosscutting concerns, i.e., a special class of design and implementation problems that challenge traditional programming paradigms, they do so in different ways. In this article we explore their relationship and their impact on modularity, which is an important prerequisite for reliable and maintainable software. Our exploration helps researchers and practitioners to understand their differences and exposes which mechanism is best used for which problem.     

Across disciplines: risk, design, method, process, and tools

In the search for solutions to make software development more predictable and controllable, one often looks for parallels in other disciplines such as architecture, bridge construction, and so on. The article looks at software development from the perspective of the electrical industry. Inspired by their management tradition, ATH techniek b.v. has learned to apply proven management techniques to software development. Simple and commonsense principles yield excellent results; for instance, developers reduced risk by estimating project effort using two different measures and by controlling execution. Comparing the software development processes with what goes on in the rest of the company or another application domain can be instructive     

结构应变的无线监测及融合技术

针对结构应变监测,设计了一类无线应变传感装置,并对该装置采集的数据进行了数据融合处理.,介绍了无线应变传感器的硬件集成;描述了基于算术平均值的无线应变传感器信息融合方法;结合应变的无线测试实验,应用数据融合技术对测量数据加以分析处理.研究表明:所集成的无线应变传感器,安装简单、携带方便;采用了数据融合处理的应变信号更加准确;基于数据融合的无线应变传感器适合在现场测试中应用.     

Plagiarism, originality, assemblage

Although students work and live in a remix culture, composition pedagogy does not always value the discursive practices of that culture, especially when it comes to producing written work for academic contexts. The reasons for these views are historically determined and tied, at least in part, to relatively traditional notions of authorship and creativity. But “writers” in other contexts, both disciplinary and popular, have developed interesting and useful remix approaches that can aid invention, leverage intellectual and physical resources, and dramatize the social dimensions of composing in this day and age. These approaches, however, ask teachers to reconsider taken-for-granted assumptions about plagiarism and originality.     

Petri nets, algebras, morphisms, and compositionality

It is shown how a category of Petri nets can be viewed as a subcategory of two sorted algebras over multisets. This casts Petri nets in a familiar framework and provides a useful idea of morphism on nets different from the conventional definition—the morphisms here respect the behaviour of nets. The categorical constructions which result provide a useful way to synthesise nets and reason about nets in terms of their components; for example, various forms of parallel composition of Petri nets arise naturally from the product in the category. This abstract setting makes plain a useful functor from the category of Petri nets to a category of spaces of invariants and provides insight into the generalisations of the basic definition of Petri nets—for instance, the coloured and higher level nets of Kurt Jensen arise through a simple modification of the sorts of the algebras underlying nets. Further, it provides a smooth formal relation with other models of concurrency such as Milner's calculus of communicating systems (CCS) and Hoare's communicating sequential processes (CSP), though this is only indicated in this paper.