Oracle 10g数据库企业版上安装配置APEX的方法

针对Oracle Application Express(APEX)最新版本(V3.2)在Oracle 10g数据库企业版上不支持以嵌入式PL/SQL网关(EPG)的模式进行安装配置的问题,提出了修正XML数据库(XDB)匿名访问的方法.通过在XDB的配置文件xdbconfig.xml中添加元素allow-repository.anonymous.access并设置为真解决XDB匿名访问的方法,成功解决XDB中APEX相关资源的访问瓶颈,并简化原有Oracle 10g数据库上安装配置APEX需要额外的Apache服务器和med_pl/sql模块支持的解决方案.通过分析解决此过程中相关问题,有利于理解Oracle XDB、EPG和APEX的内涵.     

用Oracle APEX开发基于WEB的信息系统

首先分析了当前主流的基于WEB的信息系统开发平台的优劣,指出使用Oracle APEX的优势所在;然后阐述了Oracle APEX中的组件、基本概念和体系结构;最后说明了使用Oracle APEX实现一个基于WEB的信息系统的开发方法并实现了一个实例。     

柯达热升华APEX照片零售系统

易配套照片零售系统APEX是柯达公司为数码照相照片加工零售单位新开发的一种照相加工系统,是基于热升华喷墨打印技术的一种新系统。由于其多功能及容易为照相加工服务单位配套等特点,在全世界市场上取得很大成功,本文简要报道其发展情况。     

基于暗原色先验的APEX图像复原算法

为满足有效性和处理速度的要求,结合暗原色先验的参数估计,将用于模糊处理的近似点扩展函数估计(APEX)用于天气退化图像复原。考虑到不同天气条件下、不同大小的图像其APEX参数不一致,算法能够针对不同浓度的沙尘、雾动态调整估计参数;而且与大多数多幅图像输入的复原方法不同,算法针对单幅图像进行处理。仿真结果表明算法具有很好的实用性。为进一步改善视觉效果,基于颜色恒常性能够均衡图像中光源颜色分量不均匀造成的影响,对复原图像进行了颜色恒常性处理。     

Evaluation of two empirical wind erosion models in arid and semi-arid regions of China and the USA

Wind erosion models are important tools for assessing soil erodibility and identifying management practices to control erosion. The Agricultural Policy/Environmental eXtender (APEX) model and Revised Wind Erosion Equation (RWEQ) were tested using data collected from the Tarim Basin of China and Columbia Plateau of the United States of America. Adequate performance in simulating soil loss was achieved using the original APEX model and RWEQ in respectively a cotton field and desert-oasis ecotone in the Tarim Basin and winter wheat - summer fallow (WW-SF) field in the Columbia Plateau. We calibrated the APEX model and RWEQ to improve performance because both models have many empirical parameters. After calibration, both models adequately simulated soil loss from all land use types except the RWEQ from the red date orchard in the Tarim Basin. Inadequate performance of the calibrated RWEQ in the red date orchard was likely due to underestimating maximum mass transport.     

基于APEX算法改进的图像复原算法

在高斯类点扩函数退化图像复原的研究中,提出了一种基于降晰图像频谱特征改进的APEX图像复原算法.该算法采用APEX算法的基本原理,根据图像频谱信息特征,对点扩散函数(PSF)估计过程进行了改进,采用加权最小二乘算法拟合出降晰图像频谱主方向,采用图像频谱主方向上的数据进行PSF估计,以利用更多的有效数据,从而减少PSF的估计误差.针对模拟和实际采集的降晰图像进行实验,采用主观视觉和峰值信噪比进行评价.实验结果表明,改进的算法较使用非主频谱方向上的频谱数据的复原算法在复原效果上有一定的提高.     

Hydrologic and water quality impacts and biomass production potential on marginal land

Marginal land is proposed as viable land resources for biofuel production. However, environmental impacts of perennial biomass production on marginal lands is not clear. This study defined three marginal land types and assessed their availability and potential for biofuel production in the St. Joseph River watershed. The potential impacts were evaluated using the Agricultural Policy/Environmental eXtender (APEX) model. The total area of marginal land was estimated to be 611 km² covering 21.7% of the watershed. 161 and 207 million liters of bioethanol could be produced from the marginal land utilizing switchgrass and Miscanthus, respectively. Converting marginal land currently under corn/soybean production to switchgrass and Miscanthus reduced water yield by 13.4–36.3% and improved water quality by reducing soil erosion by 27%–98%. Similarly, total nitrogen losses were reduced by 30–91% and total phosphorus losses were reduced by 65–76%, respectively, at the field scales under various energy crop production scenarios.     

用Oracle APEX开发基于WEB的信息系统

首先分析了当前主流的基于WEB的信息系统开发平台的优劣,指出使用Oracle APEX的优势所在;然后阐述了Oracle APEX中的组件、基本概念和体系结构;最后说明了使用Oracle APEX实现一个基于WEB的信息系统的开发方法并实现了一个实例。     

自适应主元提取算法及其在人脸图像特征提取中的应用

本文指出了E.Oja将统计主元分析思想用于递推网络与S.Kung自适应主元提取(APEX)算法在提取特征信息上的共同点和差异,证明了该算法的收敛性.仿真结果验证了该算法的收敛性和稳定性,分析了主元数、子图像大小及学习率参数对该算法的影响,说明了该算法在人脸识别中是一种运算量较小的有效特征提取方法.