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11.
12.
Windows 2000终端技术的研究 总被引:4,自引:0,他引:4
张宏星 《宁波工程学院学报》2004,16(2):61-63,82
Windows 2000终端是一项能降低用户“总体拥有成本”的技术,并且能为无法运行Windows 2000的计算机提供访问Windows桌面的能力。本文介绍了Windows 2000终端技术原理和Windows 2000终端网络架构,并论述了建立高效实用Windows 2000终端的方法。 相似文献
13.
The classification of agricultural tillage systems has proven challenging in the past using traditional classification methods due to the similarity of spectral reflectance signatures of soils and senescent crop residues. In this study, five classification methods were examined to determine the most suitable classification algorithm for the identification of no-till (NT) and traditional tillage (TT) cropping methods: minimum distance (MD), Mahalanobis distance, Maximum Likelihood (ML), spectral angle mapping (SAM), and the cosine of the angle concept (CAC). A Landsat ETM+ image acquired over southern Michigan and northern Indiana was used to test these classification methods. Each classification method was validated with 293 ground truth sampling locations collected commensurate with the satellite overpass. Classification accuracy was then assessed using error matrix analysis, Kappa statistics, and tests for statistical significance. The results indicate that of the classification routines examined, the two spectral angle methods were superior to the others. The cosine of the angle concept algorithm outperformed all the other classification routines for tillage practice identification and mapping, yielding an overall accuracy of 97.2% (Kappa=0.959). 相似文献
14.
基于3S不可移动文物管理系统的实现 总被引:1,自引:0,他引:1
提出对文物保护单位传统管理方式进行革新,将数据库技术、计算机网络技术、3S技术(地理信息系
统、遥感和全球定位系统)融为一体,基于GIS平台建立统一的内蒙古自治区不可移动文物信息管理系统,实现了自
治区文物数据完全共享的信息化管理和网络展示模式,为政府机关、文物机构的管理保护工作提供科学依据和决策
支持。 相似文献
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为了充分利用网格技术分布式、高性能、协同共享的能力,设计了一种基于网格和支持向量机的分布式图像分类器模型,采用网格计算技术,统筹网络运算资源,结合支持向量机在有限样本统计分类中的优势,探索网格技术在图像分类中的应用。以对遥感图像目标物体的特征提取为例,实现基于分布式计算的图像分类过程,基于.net环境的实验结果表明,该模型提高了数据密集型图像分类速度和处理效率。 相似文献
17.
A generalized regression-based model for forecasting winter wheat yields in Kansas and Ukraine using MODIS data 总被引:14,自引:0,他引:14
Wheat is one of the key cereal crops grown worldwide, providing the primary caloric and nutritional source for millions of people around the world. In order to ensure food security and sound, actionable mitigation strategies and policies for management of food shortages, timely and accurate estimates of global crop production are essential. This study combines a new BRDF-corrected, daily surface reflectance dataset developed from NASA's Moderate resolution Imaging Spectro-radiometer (MODIS) with detailed official crop statistics to develop an empirical, generalized approach to forecast wheat yields. The first step of this study was to develop and evaluate a regression-based model for forecasting winter wheat production in Kansas. This regression-based model was then directly applied to forecast winter wheat production in Ukraine. The forecasts of production in Kansas closely matched the USDA/NASS reported numbers with a 7% error. The same regression model forecast winter wheat production in Ukraine within 10% of the official reported production numbers six weeks prior to harvest. Using new data from MODIS, this method is simple, has limited data requirements, and can provide an indication of winter wheat production shortfalls and surplus prior to harvest in regions where minimal ground data is available. 相似文献
18.
The objective of this research is to develop a framework named Wise-ShopFloor and the enabling technologies for collaborative
manufacturing in a decentralized environment. Particularly, this paper presents our latest development on Web-based and sensor-driven
remote machining. Once a product design is given, its process plan and NC codes are generated by using a distributed process
planning (DPP) system. The NC codes are then used for remote machining via a standard Web browser and a Java GUI interface
running inside the browser. In this paper, the focus is given to the concept, architecture and a prototype implementation
of the enabling technology. A case study of a test part machining on a 5-axis milling machine is also completed for testing
and validation. It is expected that the developed technology can be applied to design verification via remote machining as
well as real part production in a distributed manufacturing environment. 相似文献
19.
非制冷色散式成像光谱仪辐射传递模型 总被引:1,自引:0,他引:1
根据接收信号信噪比,研究了基于非制冷微测辐射热计阵列构造色散式成像光谱仪的可行性.综合考虑目标红外辐射特性、大气传输透过率、仪器接收孔径、色散式光谱仪辐射传递特性、红外阵列探测器参数、数据链传输等环节,建立了完善的色散式长波红外成像光谱仪辐射能量传递模型.选用典型地物红外发射率数据,非制冷微测辐射热计红外焦平面阵列参数,利用低分辨率大气辐射传输计算软件LOWTRAN生成大气红外透过率曲线,依据传递模型,计算了以非制冷微测辐射热计阵列为探测器的色散式长波红外成像光谱仪可达到的光谱分辨率,验证了依据非制冷红外探测器构建小型红外成像光谱遥感器的潜力. 相似文献
20.
Password authentication has been accepted as one of the commonly used solutions in network environment to protect resources from unauthorized access. The emerging mobile Ad hoc network, however, has called for new requirements for designing authentication schemes due to its dynamic nature and vulnerable-to-attack structure, which the traditional schemes overlooked, such as availability and strong security against off line guessing attacks in face of node compromise. In this paper, we propose a threshold password authentication scheme, which meets both availability and strong security requirements in the mobile Ad hoc networks. In our scheme, t out of n server nodes can jointly achieve mutual authentication with a registered user within only two rounds of message exchanges. Our scheme allows users to choose and change their memorable password without subjecting to guessing attacks. Moreover, there is no password table in the server nodes end, which is preferable since mobile nodes are usually memory-restricted devices. We also show that our scheme is efficient to be implemented in mobile devices. 相似文献