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51.
针对互动媒体网站建设要求,利用ASP.NET2.0技术设计开发互动多媒体学习社区网站,本文对实现网上教学以及多媒体学习进行探讨。并详细介绍互动多媒体学习社区网站的主要功能设计和核心代码。  相似文献   
52.
Share price trends can be recognized by using data clustering methods. However, the accuracy of these methods may be rather low. This paper presents a novel supervised classification scheme for the recognition and prediction of share price trends. We first produce a smooth time series using zero-phase filtering and singular spectrum analysis from the original share price data. We train pattern classifiers using the classification results of both original and filtered time series and then use these classifiers to predict the future share price trends. Experiment results obtained from both synthetic data and real share prices show that the proposed method is effective and outperforms the well-known K-means clustering algorithm.  相似文献   
53.
An automated method was developed for mapping forest cover change using satellite remote sensing data sets. This multi-temporal classification method consists of a training data automation (TDA) procedure and uses the advanced support vector machines (SVM) algorithm. The TDA procedure automatically generates training data using input satellite images and existing land cover products. The derived high quality training data allow the SVM to produce reliable forest cover change products. This approach was tested in 19 study areas selected from major forest biomes across the globe. In each area a forest cover change map was produced using a pair of Landsat images acquired around 1990 and 2000. High resolution IKONOS images and independently developed reference data sets were available for evaluating the derived change products in 7 of those areas. The overall accuracy values were over 90% for 5 areas, and were 89.4% and 89.6% for the remaining two areas. The user's and producer's accuracies of the forest loss class were over 80% for all 7 study areas, demonstrating that this method is especially effective for mapping major disturbances with low commission errors. IKONOS images were also available in the remaining 12 study areas but they were either located in non-forest areas or in forest areas that did not experience forest cover change between 1990 and 2000. For those areas the IKONOS images were used to assist visual interpretation of the Landsat images in assessing the derived change products. This visual assessment revealed that for most of those areas the derived change products likely were as reliable as those in the 7 areas where accuracy assessment was conducted. The results also suggest that images acquired during leaf-off seasons should not be used in forest cover change analysis in areas where deciduous forests exist. Being highly automatic and with demonstrated capability to produce reliable change products, the TDA-SVM method should be especially useful for quantifying forest cover change over large areas.  相似文献   
54.
Large-scale simulation of separation phenomena in solids such as fracture, branching, and fragmentation requires a scalable data structure representation of the evolving model. Modeling of such phenomena can be successfully accomplished by means of cohesive models of fracture, which are versatile and effective tools for computational analysis. A common approach to insert cohesive elements in finite element meshes consists of adding discrete special interfaces (cohesive elements) between bulk elements. The insertion of cohesive elements along bulk element interfaces for fragmentation simulation imposes changes in the topology of the mesh. This paper presents a unified topology-based framework for supporting adaptive fragmentation simulations, being able to handle two- and three-dimensional models, with finite elements of any order. We represent the finite element model using a compact and “complete” topological data structure, which is capable of retrieving all adjacency relationships needed for the simulation. Moreover, we introduce a new topology-based algorithm that systematically classifies fractured facets (i.e., facets along which fracture has occurred). The algorithm follows a set of procedures that consistently perform all the topological changes needed to update the model. The proposed topology-based framework is general and ensures that the model representation remains always valid during fragmentation, even when very complex crack patterns are involved. The framework correctness and efficiency are illustrated by arbitrary insertion of cohesive elements in various finite element meshes of self-similar geometries, including both two- and three-dimensional models. These computational tests clearly show linear scaling in time, which is a key feature of the present data-structure representation. The effectiveness of the proposed approach is also demonstrated by dynamic fracture analysis through finite element simulations of actual engineering problems.
Glaucio H. PaulinoEmail:
  相似文献   
55.
If the production process, production equipment, or material changes, it becomes necessary to execute pilot runs before mass production in manufacturing systems. Using the limited data obtained from pilot runs to shorten the lead time to predict future production is this worthy of study. Although, artificial neural networks are widely utilized to extract management knowledge from acquired data, sufficient training data is the fundamental assumption. Unfortunately, this is often not achievable for pilot runs because there are few data obtained during trial stages and theoretically this means that the knowledge obtained is fragile. The purpose of this research is to utilize bootstrap to generate virtual samples to fill the information gaps of sparse data. The results of this research indicate that the prediction error rate can be significantly decreased by applying the proposed method to a very small data set.  相似文献   
56.
目前很多实际软件项目需求中都要求多个网络主机互相自动传输数据文件,而目前已有的解决方案均不能很好地满足此要求。该文首先分析了传统方案的若干缺陷,并针对性地提出一种全新的基于电子邮件的数据交换传输机制,并详细介绍了这种新传输机制的总体思路和过程,最后分析了这种新传输机制的优势。  相似文献   
57.
该文主要介绍电子政务在我国的发展,低保信息系统概述,重点阐述低保信息系统中面临的数据交换问题,并对基于XML的数据交换平台的构建进行分析。  相似文献   
58.
该文重点介绍了最新的一种关联规则后处理的方法,并且我们提出了这种方法的优化算法,能够有效去除关联规则集合中的无趣模式,并且为模式的可视化提供了良好的工具。相关实验表明该方法具有更好的模式后处理能力。  相似文献   
59.
本文提出了一种基于基因表达式编程GEP的多源时域数据融合模型GEP-MSDA,该模型可以在无任何先验知识的情况下自动对多源数据进行融合。实验表明,基于GEP的融合模型较传统方法能滤除更多的冗余数据,有效节省通信开销,并保持较高的精度。  相似文献   
60.
嵌入式系统的发展和普及应用使得在嵌入式系统平台下设计虚拟仪器成为构建仪器系统的新思路。本文提出了使用AD7864与ARM S3C2410构成数据采集系统的方案,设计了AD7864与S3C2410的接口电路;并在此硬件基础上开发了虚拟存储示波器,实现了示波器的功能。  相似文献   
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