Use of a dark object concept and support vector machines to automate forest cover change analysis

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.     

Web proxy cache replacement scheme based on back-propagation neural network

Web proxy caches are used to reduce the strain of contemporary web traffic on web servers and network bandwidth providers. In this research, a novel approach to web proxy cache replacement which utilizes neural networks for replacement decisions is developed and analyzed. Neural networks are trained to classify cacheable objects from real world data sets using information known to be important in web proxy caching, such as frequency and recency. Correct classification ratios between 0.85 and 0.88 are obtained both for data used for training and data not used for training. Our approach is compared with Least Recently Used (LRU), Least Frequently Used (LFU) and the optimal case which always rates an object with the number of future requests. Performance is evaluated in simulation for various neural network structures and cache conditions. The final neural networks achieve hit rates that are 86.60% of the optimal in the worst case and 100% of the optimal in the best case. Byte-hit rates are 93.36% of the optimal in the worst case and 99.92% of the optimal in the best case. We examine the input-to-output mappings of individual neural networks and analyze the resulting caching strategy with respect to specific cache conditions.     

信息工程专业创新人才培养模式研究

从课程体系与教学内容,教学方法与教学手段,实践能力与科学研究三个方面探讨了信息工程专业创新人才的培养模式。并提出在信息时代,只有进一步深化教学改革,加强创新实践环节,将教学与科研相结合,才能为国家和社会培养更多的拔尖信息工程专业创新人才。     

虚拟技术在计算机组装与维护实训中的应用与研究

阐述虚拟机的运行机制和特点,介绍通过虚拟机进行软件安装维护方面的典型案例,表明虚拟机可以在实训过程中替代真实的物理主机使用。     

浅淡关于平面设计的印刷色彩模式

可支持印刷的色彩模式有CMYK模式、灰度模式、位图模式和双色调模式。要提高印刷品的质量,掌握每种色彩模式的特点是关键。平面设计人员在处理图片时应先采用RGB模式处理图片的细微层次,然后再根据印刷品的实际情况谨慎转换成相应的印刷色彩模式。     

基于加噪算法的航迹模拟仿真技术研究

针对某军事外教训练系统中目标航迹模拟的特点和不足,提出了一种基于加噪算法的航迹模拟仿真方法,系统模型采用三种基本的目标运动方程模拟目标航迹,并用符合扰动分布规律的随机数进行加噪处理,实现模拟航迹的实时产生。结果证明,该方法模拟的航迹更符合目标的实际运动特性。     

短期负荷预测Volterra滤波器模型

讨论依据相空间邻近轨道演化相似性的特点构造训练模式,建立短期负荷预测Ｖｏｌｔｅｒｒａ滤波器模型的问题．以距离相似度和趋势相似度来衡量电力负荷吸引子轨道的相似度,提出了电力负荷吸引子邻近轨道判别的新方法．从模型训练充分性的角度出发,探讨了模型训练集规模的选择依据．仿真结果表明该模型是有效的．     

高校OA系统正式运行前的工作

很多高校都在进行办公自动化建设,但办公自动化(OA)系统在正式运行前一般要做什么准备工作?本文通过事例阐述了OA系统在正式运行需要经过的步骤和一些具体的实施方法,并说明了OA系统的实施,必须充分发挥各级各类人员的作用才能取得成功。最后指出,OA系统的运行并不能够彻底地废除纸质公文。     

基于项目驱动模式下的“软件工程”教学改革

本文介绍了我院针对软件工程传统教学模式的弊端,以项目为驱动,结合案例教学、团队合作等教学方法,使学生能够系统地掌握软件开发的过程、方法和工具,从而具备计算机软件系统开发和维护的能力,为学生将来的工作打下坚实的基础。     

某型防空导弹半实物仿真训练模拟系统设计

目前,某型战术防空导弹是我军主要野战防空兵器,具有技术先进、命中率高、机动性强等优点,但由于装备昂贵和一次性使用的特点,不易开展大量实装训练,以致影响了装备形成战斗力.文中运用系统仿真技术,针对防空部队某型防空导弹操作人员日常操作训练的需要,考虑部队实际应用环境和条件,设计了用于某型防空导弹操作训练的基于Pc(Personal Computer)的半实物仿真训练模拟系统,主要阐述了系统设计需求分析、系统体系结构设计,以及实现该半实物仿真训练模拟系统涉及的主要难点和关键技术,为最终实现该系统奠定了基础.