基于嵌入式Linux的农业物联网网关软件的研究与设计

为实现农业精细化种植,在基于温室大棚农业生产方式的基础上,研究并设计了一个基于嵌入式Linux的农业物联网网关软件。农业物联网网关可以接收无线传感器网络采集的环境数据,进行本地存储,同时通过网络向数据中心发送采集的环境数据;可以转发数据中心的设备控制命令,还具有远程数据查询、远程设备控制等功能,具有较高的实用性。     

基于模糊控制的农业大棚远程监控系统的研究

以带有ARM11处理器的智能模块为监控端,以PC为远程管理中心,开发了一套农业大棚环境远程监控系统。该系统监控端基于Linux系统实现对大棚环境的视频和参数采集;远程管理中心通过3G网络远程查看植物生长状况,并对采集的环境参数经模糊控制器分析后,将控制信息通过3G网络发给监控端对相关设备进行控制。本系统实现了远程监控农业大棚的功能,对国内农业走智能化发展道路具有一定的参考价值。     

基于嵌入式Linux的网络远程视频监控系统

为设计一种网络远程视频监控系统,采用以S3C2440嵌入式处理器为核心,S3C2440的USB接口为摄像头的输入、输出通道,来实现摄像头的视频采集,完成了在Linux上架设BOA服务器进行远程视频采集传输、设备控制和环境检测,实现了通过互联网对远程设备的智能控制和视频监控;该系统通过互联网进行视频播放和远程设备控制,具有可视化界面和自动获取IP的功能,而且通过NAT编程具有了穿透路由的功能;实验中系统工作稳定可靠,满足设计要求。     

一种基于网络的新型远程监控系统的设计

随着现代通信技术和计算机设备的应用和发展,远程控制技术有了长足的进步,本文设计并实现了一个基于网络的远程控制系统.计算机网络远程控制系统的构成主要包括服务端、客户端和控制信息,这是设计和实现的重点.服务端管理注册信息,实现用户命令;客户端提供网络硬件软件等系统资源,响应系统消息,反馈服务端指令;控制信息基于传输层实现,使用TCP/IP协议,控制信息包括控制资源、控制命令等.     

基于网络的除湿机远程监控系统设计及应用

为实现地下工程中除湿机的集成监控,把计算机技术、PLC网络技术和现场控制采集设备结合起来,利用串口服务器组建了一个除湿机远程监控网络。该系统用两层网络将三层设备相连,第一层是S7-200与现场设备组成的Modbus网络,第二层是由上位工控机、集线器和串口服务器组成的TCP/IP网络。上位机通过力控组态软件组态完成远程控制与数据库处理。实际应用表明,该系统应用简便,运行可靠,在工程上具有实际意义。     

虚拟专用网络在农业物联网远程监控中的应用

本文介绍了如何通过虚拟专用网络,把组成农业物联网中的由大量的数据采集节点构成监控网络采集到的数据信息进行远程传输和控制,并通过具体的应用详细说明了虚拟专用网络连接的建立和配置方法.通过信息化、数字化、智能化改变传统的农业生产模式,使得各种自动化远程控制设备得到应用,极大地提高了农业生产效率.     

基于多线程的太阳能阵列数据采集系统

针对太阳能阵列参数的远程实时监控和相关数据的网络传输等问题,利用FPGA、PC机和网络接口,设计了太阳能阵列参数等相关数据的采集、传输和远程监控系统;实现了系统的硬件电路以及相关配套软件,使系统能够利用多线程技术完成设备参数的采集和对采集数据的高速实时记录、处理、分析、显示和网络远程传输、控制等功能;经企业实际应用后证实该系统抗干扰能力强,数据吞吐量大,运算速度快且不容易死机,操作灵活,使用和升级灵活方便,便于数据的查询和分析,给生产的正常运行和故障排查带来了极大的便利,具有很强的实用性。     

基于数据库的远程测控自适应命令链设计实现

远程测试系统将分布在各个节点的测试数据、测试设备通过计算机网络连接在一起,构成一个集数据采集、传输、处理和应用的综合信息网络,实现了远程控制和操作测量仪器,获取和传递测试信息与数据;分析了传统的远程测试与控制命令链的结构,针对其缺点与不足,提出一种基于数据库的自适应控制命令的建立方法,有效地解决了传统控制命令链的灵活性低、不易扩展等缺点,使远程测试系统的通用性和可扩展性得到提高;将该方法应用于网络化远程测试与故障诊断系统中,通过向数据设备表中加入新设备的参数来动态扩充测试前端的测试设备种类,自适应生成控制命令链,实现了对远程设备的控制,取得了良好的效果。     

基于网络接口技术风光互补控制器系统的设计

设计了一种基于网络接口技术的风光互补控制器系统.通过网络接口协议转换器实现RS-232转换为Internet,进而实现Internet的接入;利用Microchip PIC16F887采集风光互补控制器系统数据;通过监控软件可以实现局域网和远程监控,对采集的相关数据和状态信息进行分析来掌握控制器的性能状态,通过远程参数设置来控制控制器的性能和故障排除.     

制药设备运行数据信息远程监控方法仿真

制药设备运行数据信息远程监控方法在远程维护设备正常运行方面非常重要,提出一种制药设备运行数据信息远程监控方法。采集和传输制药设备运行的数据信息,根据采集到的数据、制药设备运行数据集中的元素个数和设备类别集的分类数等条件确认制药设备类别隶属度矩阵,得到制药设备运行数据的远程监控值。远程监控到的设备状态和量纲变化不同,需对其值归一化处理,分别计算数据远程监控值越大越优型、越小越优型和中间型的远程监控量,获得远程监控量的告警值和良好值。并根据远程监控值对设备运行数据隶属度和聚类中心的迭代计算来确定制药设备运行数据信息的状态,将其与告警值和良好值进行对比,实现制药设备数据信息的远程监控。实验结果表明,提出方法在对制药设备运行数据信息远程监控时,能够准确的完成数据的远程监控,并且增强了远程监控的实时性。     

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。     

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.     

Editorial: Special issue on recent advances in hybrid control theory and applications

正The demands of a rapidly advancing technology for faster and more accurate controllers have always had a strong influence on the progress of automatic control theory.In recent years control problems have been arising with increasing frequency in widely different areas,which cannot be addressed using conventional control techniques.The principal reason for this is the fact that a highly competitive economy is forcing systems to operate in regimes where     

Information for Authors

正Aim The Journals of Zhejiang University-SCIENCE(A/B/C)areedited by the international board of distinguished Chinese andforeign scientists,and are aimed to present the latest devel-opments and achievements in scientific research in China andoverseas to the world’s scientific circles,especially to stimulateand promote academic exchange between Chinese and for-eign scientists everywhere.     

Enhancing a leaf radiative transfer model to estimate concentrations and in vivo specific absorption coefficients of total carotenoids and chlorophylls a and b from single-needle reflectance and transmittance

The relative concentrations of different pigments within a leaf have significant physiological and spectral consequences. Photosynthesis, light use efficiency, mass and energy exchange, and stress response are dependent on relationships among an ensemble of pigments. This ensemble also determines the visible characteristics of a leaf, which can be measured remotely and used to quantify leaf biochemistry and structure. But current remote sensing approaches are limited in their ability to resolve individual pigments. This paper focuses on the incorporation of three pigments—chlorophyll a, chlorophyll b, and total carotenoids—into the LIBERTY leaf radiative transfer model to better understand relationships between leaf biochemical, biophysical, and spectral properties.Pinus ponderosa and Pinus jeffreyi needles were collected from three sites in the California Sierra Nevada. Hemispheric single-leaf visible reflectance and transmittance and concentrations of chlorophylls a and b and total carotenoids of fresh needles were measured. These data were input to the enhanced LIBERTY model to estimate optical and biochemical properties of pine needles. The enhanced model successfully estimated reflectance (RMSE = 0.0255, BIAS = 0.00477, RMS%E = 16.7%), had variable success estimating transmittance (RMSE = 0.0442, BIAS = 0.0294, RMS%E = 181%), and generated very good estimates of carotenoid concentrations (RMSE = 2.48 µg/cm², BIAS = 0.143 µg/cm², RMS%E = 20.4%), good estimates of chlorophyll a concentrations (RMSE = 10.7 µg/cm², BIAS = − 0.992 µg/cm², RMS%E = 21.1%), and fair estimates of chlorophyll b concentrations (RMSE = 7.49 µg/cm², BIAS = − 2.12 µg/cm², RMS%E = 43.7%). Overall root mean squared errors of reflectance, transmittance, and pigment concentration estimates were lower for the three-pigment model than for the single-pigment model. The algorithm to estimate three in vivo specific absorption coefficients is robust, although estimated values are distorted by inconsistencies in model biophysics. The capacity to invert the model from single-leaf reflectance and transmittance was added to the model so it could be coupled with vegetation canopy models to estimate canopy biochemistry from remotely sensed data.     

Mr. Twinn’s bombes

This article discusses the history and design of the special versions of the bombe key-finding machines used by Britain’s Government Code & Cypher School (GC&CS) during World War II to attack the Enigma traffic of the Abwehr (the German military intelligence service). These special bombes were based on the design of their more numerous counterparts used against the traffic of the German armed services, but differed from them in important ways that highlight the adaptability of the British bombe design, and the power and flexibility of the diagonal board. Also discussed are the changes in the Abwehr indicating system that drove the development of these machines, the ingenious ways in which they were used, and some related developments involving the bombes used by the U.S. Navy’s cryptanalytic unit (OP-20-G).