生境参数,土地利用特征、水化学数据样本位置在马萨诸塞州水域进行了分析评估其影响大型无脊椎动物指标和生物完整性指数。参数和大型无脊椎动物栖息地指标从马萨诸塞州获得环保部门——流域管理分工(MA-DEP-DWM)。水质数据是来自一个不同的数据库也从MA-DEP-DWM ArcGIS 9.1。被小心地确保样本位置和生物,化学和栖息地的参数一致。示例中的差距水化学和大型无脊椎动物数据的日期不超过30天,但主要是在一周内。土地利用特征的流域和30米河岸缓冲区使用ArcGIS 9.1计算。用30米绿化带因为马萨诸塞湿地保护法禁止开发30米内的水体。一旦所有的数据合并到一个数据库,进行主成分分析和多项式回归分析评估之间的关系说明(环境)和反应(物种)变量。多项式回归方程是计算物种指标和组合。最重要的解释变量被认为是自然土地/安静的植被(河岸区和分水岭区)三个反应变量的HBI EPT指数和丰富。 The polynomial regression equations developed show a good agreement (R2 values ranging between 0.4 and 0.7) between the measured EPT Index and richness variables and those predicted by the model.展开/折叠切换
大型环境数据库从不同的公共机构获得在美国的明尼苏达州,俄亥俄和马里兰州。生物指标以及物理和化学环境变量和栖息地指标可用的一些数据。我们使用自组织映射(SOM)将数据分组为物理和化学均匀的压力团体。这些都是类似的SOM神经组(集群)或SOM神经细胞本身。使用集群的神经元时,生物指数的统计差异值被确定使用多个集群范围测试。随后,同样的程序应用于所有可用的环境变量。变量与相似的同类组织的生物完整性指数分布是解释为一个变量对生物完整性的一个重要的影响。neuron-based分析集中在回归神经元环境变量值与neuron-based生物指数。相关性最高的参数被认为是最重要的。两种方法似乎工作得很好,特别是在俄亥俄州和基于集群的分析在明尼苏达州。 Maryland also showed promising results and the separation of the sites in different strata clearly showed how the stressors are different in coastal sites than in the rest. The neuron-based analysis usually identified the same stressors in biotic integrity as the cluster-based analysis. Moreover, some of the relationships among off-stream and in-stream environmental variables as well as some of the in-stream physical variables and chemical elements could be explained. The SOM is a very powerful tool in identifying highly dimensional, with high natural variability, non-linear problems by means of data organization and pattern recognition.展开/折叠切换
损伤由于年龄或累积损伤的危害在现有结构提出了一个世界性的问题。为了评估老化的现状,变质和损坏的结构,它是至关重要的准确评估目前的情形。可以捕获结构的原位条件通过使用激光扫描仪产生密集的三维点云。本研究调查的使用高分辨率的三维地面激光扫描仪和图像捕获能力作为工具来捕获复杂场景的几何数据范围结构工程应用。激光扫描技术的不断改进,现在常见的扫描仪捕获超过每秒1000000材质贴图点~ 2毫米的精度。然而,自动从点云提取有意义的信息仍然是一个挑战,和当前最先进的需要大量的用户交互。本研究的首要目标是使用被广泛接受的点云处理步骤等登记、特征提取、分割、表面拟合和对象检测激光扫描仪的数据划分为有意义的对象群然后几种损伤诊断方法应用于这些集群。这需要建立一个过程从原料中提取重要信息的激光扫描数据集,如位置、方向和对象在扫描区域的大小,结构和位置受损区域。为此,首先处理范围数据来识别对象的方法给出了一个场景,然后一旦对象模型库是正确检测并安装到捕获的点云,这些安装对象与研究对象的初始点云定位缺陷结构。演示了算法在合成场景和验证范围二世收集的数据从测试标本和试验台桥梁。 The second objective of this research is to combine useful information extracted from laser scanner data with color information, which provides information in the fourth dimension that enables detection of damage types such as cracks, corrosion, and related surface defects that are generally difficult to detect using only laser scanner data; moreover, the color information also helps to track volumetric changes on structures such as spalling. Although using images with varying resolution to detect cracks is an extensively researched topic, damage detection using laser scanners with and without color images is a new research area that holds many opportunities for enhancing the current practice of visual inspections. The aim is to combine the best features of laser scans and images to create an automatic and effective surface damage detection method, which will reduce the need for skilled labor during visual inspections and allow automatic documentation of related information. This work enables developing surface damage detection strategies that integrate existing condition rating criteria for a wide range damage types that are collected under three main categories: small deformations already existing on the structure (cracks); damage types that induce larger deformations, but where the initial topology of the structure has not changed appreciably (e.g., bent members); and large deformations where localized changes in the topology of the structure have occurred (e.g., rupture, discontinuities and spalling). The effectiveness of the developed damage detection algorithms are validated by comparing the detection results with the measurements taken from test specimens and test-bed bridges.展开/折叠切换