电子商务的发展现状与趋势

主要从技术和管理等层面上考察和总结了电子商务的发展现状 ,阐述了电子商务发展的阶段性和商务模式特征 ,分析和总结了企业电子商务发展和应用的制约因素 ,刻画了电子商务的核心和本质 ;最后 ,展望了电子商务研究和应用的发展趋势。     

本安仪表自动测试系统的研发及其实现

介绍了本安仪表自动测试系统的功能需求和组成结构,以串行通信为基础讨论了系统软硬件设计的技术方案和实现细节,给出了系统具体器件的选型和软件模块的实现方法,描述了软硬件的整合技术和联合调试过程.通过实际测试和试用,验证和完善了系统的设计目标和指定的功能.     

基于移动代理的网格资源发现与监控模型研究

介绍了Globus中网格资源的发现和监控模型.在此基础上提出了基于移动代理网格资源发现和监控模型,并对该模型中资源发现和监控过程进行了说明.最后给出了该模型和Globus在资源的发现和监控上进行了比较,给出了该模型所具有的优点.     

面向应用的电子商务综合集成:一个新的研究领域

针对企业电子商务应用系统的复杂性、分布性和动态性,考察了电子商务综合集成研究的背景和意义,总结了其研究现状和问题,阐释了电子商务综合集成的内涵和外延。分析和提出了主要研究内容和关键问题,给出了一个初步的研究框架。     

法律合约与智能合约一致性综述

从计算机科学的角度对法律合约与智能合约的一致性研究现状进行了总结和分析。首先,分别对法律合约描述语言和智能合约开发语言进行了分类和分析,总结了每种语言的特点;其次,根据合同自动化执行的三个发展阶段对法律合约和智能合约的一致性内涵进行了分析和讨论;分别基于形式化模型和合约模板总结了由法律合约生成智能合约代码的方法和关键技术,并对其进行了讨论和评价;最后,对未来法律合约与智能合约的一致性研究进行了总结和展望。     

PLC控制系统在炼钢生产中的应用

根据西门了PLC控制系统在炼钢生产中的实例,介绍了炼钢生产的主要过程和控制方法,给出了上位机和下位机的具体参数和设计原则。投运结果表明,该系统达到了规定的性能指标和要求。     

基于ARM和DSP的数据处理系统中嵌入式应用研究

采用ARM和DSP构建了数据处理系统的基本框架,介绍了系统中嵌入式部分硬件电路设计的方案,给出了硬件连接图,对ARM和DSP之间的数据通信驱动和ARM＋Linux环境下的LCD显示驱动的设计进行了介绍,就嵌入式系统启动过程中的显示器花屏和系统运行中屏幕抖动问题进行了探讨,对图像重影和色偏进行了合理的解释并提出了相应的解决方案。     

智能家居及其发展趋势

介绍了智能家居的发展历程,阐述了智能家居的定义和功能,介绍了其关键技术和嵌入式在智能家居中的应用,预测了其发展趋势,阐明了研究智能家居的重要意义,并指出了智能家居在控制系统、智能建筑系统和计算机领域的广泛运用,将使电子科学和计算机科学等科学中产生革命性的变革.     

信息系统的结构与运营机制研究综述

文章对信息系统结构和行为的研究现状、进展和不足进行了分析和综述,剖析了当前具有典型意义的信息系统结构模式和行为特征;进而进一步研究了信息系统的逻辑结构,提出了一种信息系统的层次逻辑体系结构模型,刻画了该模型的概念框架、基本组成和工作机制,该模型的价值和意义在于突破了现有结构模型在层次视野、技术和业务逻辑的集成性、系统模型之间的相关性和协同机制、结构和行为模式的适用性等方面的限制,提供了一个动态、集成和开放的信息系统逻辑结构和工作机理分析、设计和实践模式的框架。     

基于JSF和j2ee框架的办公自动化系统设计与实现

介绍了J2EE构架技术和办公自动化的现状,对基于JSF J2EE的办公自动化系统进行了研究,提出了基于JSF和J2EE的OA系统模型,给出了该模型的基本框架、实现方案和模型特点。在介绍了JSF技术后,以企业办公自动化系统的开发和实现为实例验证了模型的正确性和有效性。     

Ecosystem functioning of protected and altered Mediterranean environments: A remote sensing classification in Doñana, Spain

Spatial heterogeneity in ecosystem functioning is a key component of ecological variability requiring special attention in the context of global change. A large history of human use has produced high physiognomic heterogeneity in Mediterranean ecosystems. However, the consequences for ecosystem functioning remain insufficiently understood. We analyzed spectral indicators of matter and energy fluxes in the land surface to classify the functional ecosystem heterogeneity in a Mediterranean region covering different management histories and protection types. We specifically analyzed the spatial variability in seasonal and annual patterns in the Normalized Difference Vegetation Index (NDVI), surface temperature (T_s) and albedo from five Landsat ETM images. Then we classified numerically this variability into ecosystem functional types (EFTs) and explored their seasonal dynamics in terms of photosynthetic radiation absorption and evapotranspiration. We identified eight main EFTs with ecologically relevant differences including contrasting dynamics in fPAR seasonality, great variation in incoming radiation reflection and differing evapotranspiration rates, particularly during the water-limitation period. Functional variability in natural vegetation mostly consisted in dissimilar annual rates of NDVI and albedo, whereas differences in seasonality were more evident in transformed areas. Similarly, the spatial distribution of EFTs was partly associated to protection, with two EFTs exclusive of protected areas and comparatively higher functional diversity in humanized areas. Landform effects on water availability in protected areas and human activities under different ecological settings were seemingly responsible for the large functional diversity of the region. We advocate for the explicit incorporation of multifunctional ecosystem heterogeneity in ecosystem management and monitoring designs.     

Desktop publishing in education

Abstract The term 'desktop publishing' has received much media coverage in recent months in both the commercial and educational press. School-based 'desktop publishing' packages are at the moment poor imitations of full-specification systems. This paper discusses the state of desktop publishing in education today and demonstrates the weaknesses of the systems available for use in the classroom. The skills required for desktop publishing are interrelated in a complex way and cannot be presented in a hierarchical fashion. A model of the functional processes involved is suggested in the paper and analysed in terms of the skills required.     

关联规则挖掘技术研究进展*

为帮助人们深入研究关联规则挖掘技术,总结了关联规则的分类方法、评价方法以及相关技术的最新进展,特别是对关联规则的主要算法进行了详细的介绍,并探讨未来的发展方向。该研究比较系统全面,对将来进一步深入分析关联规则挖掘技术具有指导意义。     

基于HSV色彩空间的MODIS云检测算法研究

云是一种自然现象,广泛、高频、不规律地出现在地球上空,因此云也经常在卫星影像上有所体现。在遥感影像中,云覆盖在很大程度上降低了数据的质量和利用率。云检测是进行遥感数据处理与分析的基础和必要环节,因此准确地提取云区所在位置是一个非常有意义的研究课题。提出基于HSV色彩空间的MODIS云检测算法,首次将HSV色彩空间引入云检测领域,提出的算法以云与其他地物的自身光谱特性和光谱差异为理论基础,以色彩空间HSV正变换为数学基础,将MODIS波段1、6和26的假彩色合成影像进行HSV正变换,对获得的色调值（H）进行简单的、客观的阈值限定,获得最后的云检测效果。该算法具有精度高、简单可行、客观性强和计算速度快等特点,适用于不同的下垫面和季节,云检测效果理想。     

Production control: Current developments and future trends

Manufacturing industry is going through a period of unprecedented change as a result of the developments in micro-electronic technology. This is bringing about a transformation not only in hardware, in the form of computer-aided manufacturing, but in the manner in which production is organised and controlled.It is in the latter connection that the present paper sets out to review current developments and future trends. In particular the machine readable bar-code is seen as a key element in extending computerised control to cover not only the machines, but tools, materials and parts and their movement in the development of fully integrated manufacturing systems.As the move towards automation gathers pace it is forecast that manufacturing industry will become more process industry like in form, with consequences for the way in which production is organised and controlled.Finally consideration is given to the manner in which these current developments in the field of production are giving rise to a structural alteration in industrial labour requirements in which, in the future, fewer people will be required but on highly enriched work tasks.     

The influence of IT: perspectives from five Australian schools

Abstract Information and Communication Technologies (ICT) are now widespread in Australian schools but with variation in how, where, when and how much they are used. Computers may be located in a computer laboratory, distributed throughout the school, or students may use their own laptop computers. IT may be a subject in its own right or ICT may be used across all areas of the curriculum. It is how ICT is used in the school setting that is important in providing students with the skills to be participate in a 'knowledge society'. This paper examines the ways in which information and communication technologies influence teaching and learning in five Australian schools. Data were gathered through observation, interviews and document analysis in schools operating at the elementary and secondary grades in relatively technology rich environments. Each of the schools participated in the Australian component of the Second Information Technology in Education Study – Module 2 (SITES-M2) of innovative pedagogical practices. Several of the studies were of specific projects where ICT was the key enabler of the learning programme. Others focused on an entire school's approach to ICT as an agent for changed approaches to learning.     

Combined effects of fabric air permeability and moisture absorption on clothing microclimate and subjective sensation during intermittent exercise at 27 degrees C

The present paper aimed at determining the combined effects of two different levels of air permeability and moisture absorption, in terms of clothing microclimate and subjective sensation, in resting and exercising subjects at an ambient temperature of 27 °C, a relative humidity of 50% and an air velocity of 0.14 m s^-1. Three kinds of clothing ensemble were investigated: (1) polyester clothing with low moisture absorption and low air permeability (A), (2) polyester clothing with low moisture absorption and high air permeability (B), and (3) cotton clothing with high moisture absorption and high air permeability (C). The subjects exercised for 10 min on a cycle ergometer at an intensity of 30% maximal oxygen uptake and then had a 10 min rest. This sequence was repeated four times. The main findings are summarized as follows: (1) The clothing microclimate humidity in the back area was significantly higher in A than in B, and in C than in B. (2) The clothing microclimate temperature in the chest area was significantly higher in B than in A, and in B than in C. (3) The clothing microclimate temperature in the back area was significantly higher in C than in B. (4) The clothing surface temperature was significantly higher in C than in B. (5) Although the positive relationships between the microclimate humidity and forearm sweat rate was significantly confirmed in all three kinds of clothing, the microclimate humidity at chest for the same sweat rate was lower in C than in A and B. (6) Although the positive relationships between subjective sensation and forearm sweat rates were significantly confirmed in all three kinds of clothing, the subjective discomfort seemed to be reduced more effectively in C than in A and B for the same sweat rate. These results were discussed in terms of thermal physiology and combined effects of air permeability and moisture absorbency of the fabrics.     

Thermodynamics of martensitic transformations in the framework of the CALPHAD approach

Martensitic phases occur in a number of metallic materials, and are metastable in many systems. They have been of significant importance in steels for a long time, and have generated a great interest in Shape Memory Alloys (SMA) in recent years. This review describes a thermodynamic and kinetic approach for modelling martensitic phases in the framework of the CALPHAD approach.     

生物组织光声成像技术综述

光声成像是一种低功率、非电离的成像方式,既具有声学方法对深层组织成像分辨率高的优点,又具有光学方法在功能成像、分子成像方面具有高对比度的优势。本文回顾了近年来,光声成像技术在生物医学领域的研究进展,介绍了光声成像的基本成像原理。以此为基础,本文介绍了光声成像的两种主要成像方案：光声断层成像和光声显微镜,并且讨论了光声成像在获取生物组织化学成分信息和微结构信息方面的优越性;最后,本文对光声成像技术的优点和应用前景进行了总结。     

基于RAM结构的CAM的VerilogHDL设计

该文介绍了以FPGA芯片中RAM结构为核心,使用VerilogHDL设计CAM的方案。该CAM的数据深度和宽度易于扩展,匹配查找速度快。