ZigBee无线传感器网络在瓦斯监测系统中的应用

为了提高矿井下瓦斯检测系统的安全性和稳定性,采用了基于ZigBee的无线通信技术和基于DEEH算法的无线传感器网络,以CC2430为传感器节点,设计了瓦斯浓度监测系统。实验结果表明,该系统完全符合瓦斯浓度监测的要求,可以有效地减少事故的发生,降低人员的伤亡.     

红外瓦斯无线传感检测系统设计与实现

针对煤矿瓦斯测量精度问题,在研究矿井瓦斯检测技术的基础上,基于红外光谱吸收原理,采用无线传感网络技术,设计了红外瓦斯无线传感检测系统,该系统采用差分检测技术,利用数据拟合解调出出瓦斯浓度,并利用ZigBee无线网络技术组建检测网络,实现了矿井瓦斯浓度的精确探测;实验结果表明,通过对11组数据进行测量和比较,红外瓦斯无线传感网络检测系统的平均绝对误差为0.091%,实现了瓦斯浓度的全量程精确检测,具有探测灵敏度高、测量误差小、传输距离远和组网灵活等优点,能够满足矿井瓦斯浓度检测的需求,具备了实用基础。     

面向矿井瓦斯监测的ZigBee无线传感网系统设计

针对传统有线传感网在井下进行瓦斯监测存在使用成本高、移动性差及覆盖范围有限等问题,设计了一种面向矿井瓦斯监测的ZigBee无线传感网系统。该系统利用采集节点实时采集井下瓦斯浓度,采用ZigBee协议将瓦斯浓度数据实时传输至汇聚节点,由汇聚节点汇总并传输至嵌入式网关,数据经嵌入式网关解析处理后转发至矿井监控中心,从而实现井下瓦斯监测数据的实时显示。实验结果表明,该系统具有较高的可靠性和较好的实时性,覆盖范围广。     

基于ZigBee的智能瓦斯报警矿灯设计

针对传统瓦斯检测方法只是对矿井某些重点位置进行不间断监测的问题,设计了一种基于ZigBee的智能瓦斯报警矿灯。该矿灯作为ZigBee网络中的移动节点,采用LED光源、锂电池供电,具有瓦斯检测、无线定位、ZigBee通信、充电管理及保护等功能。测试结果表明,该矿灯的实际参数和通信功能均满足设计要求,可实现煤矿井下瓦斯检测的全方位覆盖。     

ZigBee的新型矿用无线瓦斯传感器研究

煤炭是我国的主要能源,而生产安全是煤矿工作的重中之重。本文设计了基于ZigBee的矿用无线瓦斯监测系统,使井下工作人员可以实时地监测各处瓦斯浓度,以便及时处理安全隐患,可极大程度地提高井下的安全保障。     

基于ZigBee无线网络技术的矿井监测系统设计

在研究ZigBee的IEEE802.15.4标准通信协议的基础上,提出了基于ZigBee无线传感器网络的矿井监测系统架构,主要介绍了对煤矿井下温度、湿度和瓦斯气体浓度监测的全新的无线传感器网络的体系设计及无线网络监测系统数据采集与传输的软硬件,实现了监测信号的获取和无线传输。这一设计方案解决了大量监测点的无线组网,在矿井监测系统中得到成功应用。     

基于ZigBee的瓦斯监测系统设计

提出基于ZigBee无线传感器网络技术及红外吸收光谱检测的瓦斯监测系统,介绍系统架构、硬件方案和软件设计.     

甲烷光纤传感检测系统的设计

针对目前煤矿瓦斯气体检测存在测量误差和测量不稳定的问题,文章提出了一种新型的基于甲烷气体光谱吸收特性的甲烷光纤传感检测系统,阐述了甲烷气体浓度的检测原理,介绍了甲烷光纤传感检测系统的工作原理设计、光源选择等。该系统可实现对矿井瓦斯可靠、高效、实时的监测。     

基于51单片机和VB6.0的瓦斯浓度监测系统

文章介绍了一种基于AT89C2051单片机和VB6.0的瓦斯浓度监测系统的组成、工作原理及硬件、软件设计方法。该系统不仅可实现对矿井瓦斯浓度的实时监测与预警,还具有瓦斯增长率报警功能,为预防和减小瓦斯火灾损失提供了科学手段。     

基于ZigBee的高压开关SF6气体泄漏监测系统设计

针对高压开关对SF6气体泄漏监测的需要,分析了现有监测技术存在的缺陷,提出了以ZigBee无线传感网络技术为基础的高压开关SF6气体泄漏监测新方法。采用红外吸收光谱检测原理,实现SF6气体浓度的精确测量,以CC2530单片机为控制处理核心,控制SF6气体浓度数据的采集、处理与传输,实现自组网无线浓度监测。文中介绍了系统架构、硬件方案和软件设计。     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

How do children do mathematics with LOGO?

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.