Civil and Environmental Engineering Challenges for Data Sensing and Analysis

The objective of this study was to identify challenges in civil and environmental engineering that can potentially be solved using data sensing and analysis research. The challenges were recognized through extensive literature review in all disciplines of civil and environmental engineering. The literature review included journal articles, reports, expert interviews, and magazine articles. The challenges were ranked by comparing their impact on cost, time, quality, environment and safety. The result of this literature review includes challenges such as improving construction safety and productivity, improving roof safety, reducing building energy consumption, solving traffic congestion, managing groundwater, mapping and monitoring the underground, estimating sea conditions, and solving soil erosion problems. These challenges suggest areas where researchers can apply data sensing and analysis research.

Comparison of Camera Motion Estimation Methods for 3D Reconstruction of Infrastructure

Camera motion estimation is one of the most significant steps for structure-from-motion (SFM) with a monocular camera. The normalized 8-point, the 7-point, and the 5-point algorithms are normally adopted to perform the estimation, each of which has distinct performance characteristics. Given unique needs and challenges associated to civil infrastructure SFM scenarios, selection of the proper algorithm directly impacts the structure reconstruction results. In this paper, a comparison study of the aforementioned algorithms is conducted to identify the most suitable algorithm, in terms of accuracy and reliability, for reconstructing civil infrastructure. The free variables tested are baseline, depth, and motion. A concrete girder bridge was selected as the "test-bed" to reconstruct using an off-the-shelf camera capturing imagery from all possible positions that maximally the bridge's features and geometry. The feature points in the images were extracted and matched via the SURF descriptor. Finally, camera motions are estimated based on the corresponding image points by applying the aforementioned algorithms, and the results evaluated.

Machine Vision Enhanced Post-earthquake Inspection

Camera motion estimation is one of the most significant steps for structure-from-motion (SFM) with a monocular camera. The normalized 8-point, the 7-point, and the 5-point algorithms are normally adopted to perform the estimation, each of which has distinct performance characteristics. Given unique needs and challenges associated to civil infrastructure SFM scenarios, selection of the proper algorithm directly impacts the structure reconstruction results. In this paper, a comparison study of the aforementioned algorithms is conducted to identify the most suitable algorithm, in terms of accuracy and reliability, for reconstructing civil infrastructure. The free variables tested are baseline, depth, and motion. A concrete girder bridge was selected as the "test-bed" to reconstruct using an off-the-shelf camera capturing imagery from all possible positions that maximally the bridge's features and geometry. The feature points in the images were extracted and matched via the SURF descriptor. Finally, camera motions are estimated based on the corresponding image points by applying the aforementioned algorithms, and the results evaluated.

A validation of commercial flow solver performance on hybridised octree meshes

In recent years we have been developing a meshing system which is aimed at eliminating the bottleneck represented by building meshes for real-world, complex turbomachinery configurations. This system is based on a rapid octree meshing technology which is then made conformal to the bodies present. The objective of this paper is to demonstrate that this class of mesh is not only very fast to produce but also fit-for-purpose in the sense that simulations generated with third-party commercial flow solvers like Fluent have the same accuracy as those performed on more conventional meshes. A range of standard examples and test cases will be presented. Copyright © 2011 by ASME.

中华鳖转“全鱼”生长激素基因研究

河南省自然科学资金项目(编号:0124040022)资助

生活污水对蝌蚪红细胞微核及核异常的诱导

利用青蛙蝌蚪红细胞微核试验,检测了城市生活污水处理厂各级处理工艺出水的诱变活性。在l6d生话污水处理的实验中,青蛙蝌蚪红细胞微核细胞率及核异常率2d后就呈现统计上的显著增加,并随暴露时间的延长而增高,第8天达到最大值。在不同浓度混合污水暴露实验中,蝌蚪红细胞微核细胞率和核异常率呈现明显的剂量依赖性增加。实验结果表明:城镇生活污水具有较强的诱变活性,一级和二级处理工艺出水也具有一定的诱变活性。现有污水处理工艺有待于进一步改进。

武汉东湖上覆水和沉积物中磷形态的垂直分布特征

武汉东湖是有代表性的城市浅水型湖泊。于春、夏两季对东湖庙湖湖区的上覆水和沉积物柱状样品进行了磷的形态分析,研究了各种磷形态在上覆水及沉积物垂直方向上的分布特征。结果表明,春夏两季东湖上覆水总磷(TP)含量分别为1.11和1.25mg·L-1,超过国家标准近6倍,富营养化程度严重。春季湖水中磷主要以颗粒态形式存在,夏季主要以溶解态形式存在。春季湖区沉积物中铁结合磷(Fe-P)比例最大,占沉积物TP的44.3%,夏季闭蓄磷(OcP)比例最大,占TP的36.3%,高比例的Fe-P从沉积物角度说明了庙湖湖区的污染

银鲫生殖方式多样性的转铁蛋白和同工酶标记的遗传分析

用银鲫克隆D、克隆A和鲤鱼的精子分别与银鲫克隆F的卵子受精产生了三种繁殖组合FD、LA和FL;再用转铁蛋白和同工酶标记对这三种组合的遗传模式进行比较研究。结果发现,FL���合的子代具有与其母本完全相同的体形和电泳图谱,表现出雌核生殖银鲫的克隆品性。而在FD组合中则出现了体形的分化和酶谱的多态性;在一些个体的蛋白座位上同时检测到了父本和母本各自特有的谱带,证明FD生殖过程中有性重组的发生。同时,在所研究的蛋白的不同座位上存在着极端的连锁不平衡现象,可以推断在FD的重组过程中多个基因座位组成的连锁群(甚至是染色

Off-wall boundary conditions for turbulent flows obtained from buffer-layer minimal flow units

There is strong evidence that the transport processes in the buffer region of wall-bounded turbulence are common across various flow configurations, even in the embryonic turbulence in transition (Park et al., Phys. Fl. 24). We use this premise to develop off-wall boundary conditions for turbulent simulations. Boundary conditions are constructed from DNS databases using periodic minimal flow units and reduced order modeling. The DNS data was taken from a channel at Reτ=400 and a zero-pressure gradient transitional boundary layer (Sayadi et al., submitted to J. Fluid Mech.). Both types of boundary conditions were first tested on a DNS of the core of the channel flow with the aim of extending their application to LES and to spatially evolving flows.

Multi-objective shape optimisation for horizontal-axis wind turbine blades

We are developing a wind turbine blade optimisation package CoBOLDT (COmputa- tional Blade Optimisation and Load De ation Tool) for the optimisation of large horizontal- axis wind turbines. The core consists of the Multi-Objective Tabu Search (MOTS), which controls a spline parameterisation module, a fast geometry generation and a stationary Blade Element Momentum (BEM) code to optimise an initial wind turbine blade design. The objective functions we investigate are the Annual Energy Production (AEP) and the fl apwise blade root bending moment (MY0) for a stationary wind speed of 50 m/s. For this task we use nine parameters which define the blade chord, the blade twist (4 parameters each) and the blade radius. Throughout the optimisation a number of binary constraints are defined to limit the noise emission, to allow for transportation on land and to control the aerodynamic conditions during all phases of turbine operation. The test case shows that MOTS is capable to find enhanced designs very fast and eficiently and will provide a rich and well explored Pareto front for the designer to chose from. The optimised blade de- sign could improve the AEP of the initial blade by 5% with the same flapwise root bending moment or reduce MY0 by 7.5% with the original energy yield. Due to the fast runtime of order 10 seconds per design, a huge number of optimisation iterations is possible without the need for a large computing cluster. This also allows for increased design flexibility through the introduction of more parameters per blade function or parameterisation of the airfoils in future. © 2012 by Nordex Energy GmbH.