基于改进CAPSO的原油管道调合多性质优化方法

在仔细研究原油管道调合工艺基础上,提出一种基于改进有约束自适应粒子群优化(CAPSO)算法的原油管道调合多性质优化方法;首先,基于原油调合规则库、优化预处理及设备实际工作能力约束,建立了多原油多性质优化模型;然后,根据原油调合目标,通过CAPSO算法对优化模型进行快速、准确的优化计算,获得多种组分原油的最优配比;投运效果表明,系统能够自动、高效计算出原油调合的最优配比,避免人工计算所造成的一致性差,计算效率低并且不易获得最佳配比的问题,有效提高了加工设备的生产效率。     

IBI and CA Model based Extraction of Urban Built\|up Areaand Its Application：A Case Study in Shanghai

At present,the automatic extraction of urban built\|up area is still a problem.Taking Shanghai city as an example,this research uses the binary image,which was derived from an IBI(index\|based built\|up index)image,as the geographical cellular automaton initial input data.This was then imported to the extended cellular automata model for further processing.After a series of processing such as thresholding,corrosion and connectivity test,the urban built\|up area was simulated and can be extracted.Based on this method,the urban built\|up area of Shanghai in five different years between 1987 and 2015 was extracted using multi\|temporal Landsat images of Shanghai.In addition,the urban growth intensity index,the concentric buffers analysis and radar chart analysis were calculated and used to analysis spatiotemporal pattern of Shanghai urban expansion in the 28 study years.The result shows that the built\|up area of Shanghai was expanded from 195 km² in 1987 to 1759 km² in 2015,which is eight times as large as that in 1987.In the period between 1987 and 2002,the urban built\|up area expanded mainly along the North\|South axis of the Huangpu River.However,after 2002 the expansion rate was increased more quickly,and the direction of the expansion was shifted to an east to west direction.Generally speaking,Shanghai has experienced a rapid urban expansion in the recent three decades.     

基于演化计算的异常轨迹并行检测算法

异常轨迹检测是轨迹数据挖掘研究领域的一个重要研究内容,基于演化计算的异常轨迹检测算法(Top-k evolving trajectory outlier detection, TOP-EYE)是一种有效的异常轨迹检测算法。不同于其他算法采用的轨迹距离计算方法,TOP-EYE算法 从轨迹的方向和密度角度出发,采用演化计算的方式检测异常。为了提高TOP-EYE算法对海量轨迹数据集异常检测的效率,本文在其基础上提出了基于MapReduce的异常轨迹检测并行算法(Parallel detecting abnormal trajectory based on TOP-EYE, PDAT-TOP ),利用MapReduce并行计算的优势提高了异常轨迹检测的效率。将算法PDA T-TOP在Hadoop平台上加以实现,实验结果表明,算法PDAT-TOP能够有效地检测异常轨迹,并且具有较高的可扩展性和加速比。     

新型人体参数自动测量系统

目的 针对国内外已有的非接触式测量系统普遍存在价格昂贵、安装复杂、占用空间大等问题,提出一种基于消失点和图像比例法相结合的人体参数尺寸的自动测量方法(HuFAMS-VP)。方法 首先,利用背景差分法,将人体从图像中分割出来;再将分割后的人体图像进行轮廓提取,从而获得人体轮廓图;然后,根据边缘检测和人体各个部位与人体身高比例等方法,获取人体几个关键部位特征点;最后,通过消失点方法(vanishing point)与比例法的结合获取人体参数尺寸。结果 根据HuFAMS-VP对7组被测人员(年龄在25±3岁,身高范围在1.7±0.2 m)进行尺寸测量,并与被测人员真实尺寸信息进行比较。由测量结果可以得到7组被测人员的绝对误差控制在±0.05 m之内,平均测量速度在2 s以内。结论 HuFAMS-VP在确保测量精度的前提下,具有操作方便、价格低廉等优势。根据测量结果,论证了本系统的准确性和鲁棒性。     

流程图化的嵌入式系统开发平台

面向嵌入式零代码基础使用者和低成本开发者,搭建了一个基于STM32的软硬件一体化编程的流程图化的嵌入式系统开发平台.该平台采用STM32作为硬件载体,用QT跨平台C++图形用户界面搭建简单易懂的流程图操作界面.硬件框图界面能驱动嵌入式设备,用编译软件封装功能模块放置功能编辑盒,通过命令行调用编译器,调用外部烧录软件完成下载,代码查看器可直观监视编译全过程.测试结果表明,该平台可方便、快捷解决编程问题.     

An algorithm for automatic 2D finite element mesh generation with line constraints

In this study, an algorithm is designed specifically for automatic finite element (FE) mesh generation on the transverse structure of hulls reinforced by stiffeners. Stiffeners attached to the transverse structure are considered as line constraints in the geometry boundary. For the FE mesh generation used in this study, the line constraints are treated as boundaries and by that means the geometry domain attached to the line constraints is decomposed into sub-domains, constrained only by the closed boundaries. Then, the mesh can be generated directly on those sub-domains by the traditional approach. The performance of the proposed algorithm is evaluated and the quality of the generated mesh meets expectations.     

Human foot modeling towards footwear design

Comfort test of footwear is mainly based on subjective perception of the wearer and a large number of subjects are required to obtain a reliable result. Therefore, the subjective comfort test is expensive and time consuming. Although the foot size and shape of a subject can be obtained by using a three-dimensional (3D) foot scanner, it is still difficult to create foot motion animations of each subject suitable for computer simulation.In this paper, we propose a fast approach to model foot deformation and present its application in simulating interaction with footwear towards footwear design. The simulation determines deformation of foot and footwear models. It can also determine stress distribution in the footwear. Given an initial foot model and a captured foot motion, human foot animation is created first. Then, the footwear model is fitted to the foot to compute the deformation and stress in the footwear. In this article, the boundary element method (BEM) is adopted. We demonstrate the results by conducting simulation of a captured gait motion. Experimental results showed that the method can be used to simulate human gait motion, and can determine deformation of footwear.     

Vortex pattern and wave motion produced by a bottom blunt body moving at a critical speed

An underwater object moving at a near-critical speed in a shallow-water domain had been observed to generate a sequence of upstream propagating solitary waves with an elongated depression of water surface and a train of dispersive waves followed in the downstream. This study presents the development of a two-dimensional stream function–vorticity based viscous fluid model with satisfied nonlinear free-surface conditions to study the generation of solitary waves and the induced vortex motion under the forcing of a moving object. A combined finite analytic and finite difference method is adopted to solve the flow field equations and free-surface boundary conditions in a transient curvilinear coordinate system. The model is shown to produce free-surface elevations in fairly good agreements with published results for a test case of a moving smooth bump. Other tests for the generation of recirculation zone behind a body of square shape in a confined fluid domain are also conducted to further verify the model performance. The results showing the generation of upstream advancing solitary waves and downstream vortex pattern by a blunt rectangular body moving at a critical speed along the bottom in a domain with free surface are presented. Comparisons of results from potential flow and viscous flow conditions are made to demonstrate the importance of viscosity to the wave generation. Different from the relatively regular vortex pattern occurred under the case of Re = 3500, the transition of the vortex motion for a larger Reynolds number (e.g. Re = 35,000) evolves without a regular pattern throughout the generation process of the advancing solitons. The effects of the size and bluntness of a moving object on the generated flow field and free-surface elevations are also analyzed and discussed.     

Water property monitoring and assessment for China's inland Lake Taihu from MODIS-Aqua measurements

We provide results of quantitative measurements and characterization for inland freshwater Lake Taihu from the Moderate Resolution Imaging Spectroradiometer (MODIS) on the satellite Aqua. China's Lake Taihu, which is located in the Yangtze River delta in one of the world's most urbanized and heavily populated areas, contains consistently highly turbid waters in addition to frequent large seasonal algae blooms in various lake regions. Thus, satellite data processing requires use of the shortwave infrared (SWIR) atmospheric correction algorithm. Specifically for Lake Taihu, an iterative SWIR-based atmospheric correction algorithm has been developed and proven to provide reasonably accurate water-leaving radiance spectra data. Using MODIS-Aqua measurements, the blue-green algae bloom in Lake Taihu in 2007 has been studied in detail, demonstrating the importance and usefulness of satellite water color remote sensing for effectively monitoring and managing a bloom event.Seasonal and interannual variability, as well as spatial distributions, of lake water properties were studied and assessed using the MODIS-Aqua measurements from 2002 to 2008. Results show that overall waters in Lake Taihu are consistently highly turbid all year round, with the winter and summer as the most and least turbid seasons in the lake, respectively. Extremely turbid waters in the winter are primarily attributed to strong winter winds that lead to significant amounts of total suspended sediment (TSS) in the water column. In addition, MODIS-Aqua-measured water-leaving radiance at the blue band is consistently low in various bay regions in Lake Taihu, indicating high algae concentration in these regions. Climatological water property maps, including normalized water-leaving radiance spectra nL_w(λ), chlorophyll-a concentration, and water diffuse attenuation coefficient at the wavelength of 490 nm (K_d(490)), are derived from all MODIS-Aqua data from 2002 to 2008 for Lake Taihu, showing overall spatial distribution features for the lake water property.