基于贝叶斯模型与最佳伙伴相似度量的目标跟踪

提出了一种基于产生式与判别式联合模型的视觉目标跟踪算法。首先介绍了一种基于全局颜色特征直方图特征的贝叶斯分类器,检测出若干最有可能属于目标的候选区域,然后利用最佳伙伴相似性度量（Best-Buddies Similarity）得到候选区域与目标模板的相似度,结合概率值与相似度值估计出最优的目标状态。通过划分目标-背景区域模型、目标-干扰区域模型,对可能产生干扰的区域提前进行抑制,降低了长期跟踪可能产生的漂移问题的风险,同时引入了自适应尺度估计机制和在线模型更新策略,以获得更为精准的跟踪结果。在37组具有挑战性的图像序列上与7种优秀的算法对比实验表明,所提出的算法能够有效应对光照变化、遮挡、旋转与尺度变化等多种问题。     

抗病毒类化合物结构与离解速率的关系

为了解决如何筛选出更加有效的抗病毒类化合物的问题,研究了离解速率(k_(off))与抗病毒类药物结构的关系,理论依据是k_(off)常用于评价药物在人体开放性系统中的活性.首先,应用分子描述符软件计算出每个抗病毒类化合物的分子描述符,并使用多元逐步回归分析法、偏最小二乘法和遗传算法3种方法对描述符进行筛选.然后,分别采用支持向量机和BP神经网络方法建立抗病毒类化合物的k_(off)的预测模型,并用测试集对模型进行了验证.结果表明:筛选出了具有良好预测能力的描述符,建立的2个预测模型经验证均合理,对未来抗病毒类药物的研制具有指导意义.     

雾霾污染下基于混沌性的图像去雾算法改进

传统基于边缘保持滤波的单幅图像快速去雾算法,在雾霾污染大气粒子散射作用下,图像会受到雾化背景的干扰,出现浓雾噪点,图像结构信息复原效果较差.提出一种基于混沌性的加权滤波图像快速去雾算法,通过分析雾天雾化背景干扰下的图像信息,获取图像数据的混沌特性,并对雾化图像进行最小颜色分量估计.在此基础上,结合带雾图像暗原色模型、时域和频域特征分量模型,构建出自适应加权滤波模型,完成基于混沌性的加权滤波图像快速去雾算法的改进设计.实验结果表明,采用该算法能避免雾化图像中间区域的颜色失真,降低雾化背景干扰,减少浓雾噪点,使远景的混沌特征得到合理的保留,在图像质量和运算性能方面都具有优越性.     

Study on dynamic response of multi-body structure under explosive driving

In this study, a complex multi-body structure was proposed, and the mechanism for the dynamic response of the structure under explosive driving was investigated by using the Lagrange equations of the second kind. An initial value subject to explosion loading was analyzed to develop the theoretical model of the dynamic response, and the centroid trajectory of three different structural shapes was solved. To verify the accuracy of the theoretical model, numerical simulation via finite element analysis within LS-DYNA and a dynamic experiment were conducted, and the consistent dynamic response process of the multi-body structure was obtained. In addition, the dynamic response time of the multi-body structure under different explosion loading conditions was calculated by the theoretical model, numerical simulation, and experimental investigation. It was found that the increased opening charge mass reduces the dynamic response time.     

Dynamic data packing towards the optimization of QoC and QoS in networked control systems

A class of networked control systems is investigated whose communication network is shared with other applications. The design objective for such a system setting is not only the optimization of the control performance but also the efficient utilization of the communication resources. We observe that at a large time scale the data packet delay in the communication network is roughly varying piecewise constant, which is typically true for data networks like the Internet. Based on this observation, a dynamic data packing scheme is proposed within the recently developed packet-based control framework for networked control systems. As expected this proposed approach achieves a fine balance between the control performance and the communication utilization: the similar control performance can be obtained at dramatically reduced cost of the communication resources. Simulations illustrate the effectiveness of the proposed approach.     

Field study on performance of new technique of geosynthetic-reinforced and pile-supported embankment at bridge approach

Vehicle bumps at a bridge approach caused by the differential settlement between a bridge and an adjacent backfill embankment are one of the most difficult problems in geotechnical engineering. Large vehicle bumps make drivers uncomfortable and cause large impact loads on vehicles and the bridge abutment. A new ground-improvement technique called fixed-geosynthetic-reinforced and pile-supported embankment(FGT embankment) was developed and used to alleviate vehicle bumps at a trial bridge-approach site located in central China. To distribute the differential settlement between the bridge and adjacent backfill embankment over a long transition zone, the following three techniques were used at the trial bridge-approach site:(a) the FGT embankment,(b) conventional geosynthetic-reinforced and pile-supported embankment(CT embankment), and(c) geosynthetic-reinforced embankment without piles(GR embankment). The performance of all three techniques in the field trial was investigated by field measurements involving earth pressure cells, geosynthetic deformation sensors, and settlement gauges. The FGT and CT embankments exhibited better performance than the GR embankment. Compared with the CT embankment, the FGT embankment was more effective at ground improvement. At an elevation of 4.0 m from the base of the embankment, the pressures below the geosynthetic were smaller than those above the geosynthetic at the closest measurement point. The difference between the pressures between above and below the geosynthetic tended to increase with the embankment height.     

Investigation of Barree-Conway non-Darcy flow effects on coalbed methane production

Coalbed gas non-Darcy flow has been observed in high permeable fracture systems,and some mathematical and numerical models have been proposed to study the effects of non-Darcy flow using Forchheimer non-Darcy model.However,experimental results show that the assumption of a constant Forchheimer factor may cause some limitations in using Forchheimer model to describe non-Darcy flow in porous media.In order to investigate the effects of non-Darcy flow on coalbed methane production,this work presents a more general coalbed gas non-Darcy flow model according to Barree-Conway equation,which could describe the entire range of relationships between flow velocity and pressure gradient from low to high flow velocity.An expanded mixed finite element method is introduced to solve the coalbed gas non-Darcy flow model,in which the gas pressure and velocity can be approximated simultaneously.Error estimate results indicate that pressure and velocity could achieve first-order convergence rate.Non-Darcy simulation results indicate that the non-Darcy effect is significant in the zone near the wellbore,and with the distance from the wellbore increasing,the non-Darcy effect becomes weak gradually.From simulation results,we have also found that the non-Darcy effect is more significant at a lower bottom-hole pressure,and the gas production from non-Darcy flow is lower than the production from Darcy flow under the same permeable condition.     

钢曲杆在高温（火灾）下的力学特征数值分析

高温(火灾)环境下钢曲杆的受力和变形将会产生较大变化,对结构的力学特征影响较大。本文根据结构稳定理论和热力学原理,应用有限元分析方法,结合三种不同工况,分别探讨了高温(火灾)环境下不同支座形式、杆截面形式等因素对钢曲杆力学特征的影响,并对三种工况下钢曲杆力学特征进行了数值分析与对比,得出了H型钢截面无铰钢曲杆更加符合建筑安全要求的结论,研究成果可为钢曲杆抗火研究提供参考。     

莠去津磁性分子印迹材料制备与吸附应用研究

以莠去津(atrazine)为模板分子,甲基丙烯酸(methyl acrylic acid,MAA)为功能单体,Fe3O4磁性纳米微球为载体,制备了具有特异性识别莠去津的磁性分子印迹聚合物。通过Langmuir等温吸附模型得莠去津分子印迹聚合物(atrazine-magnetic molecularly imprinted polymer,AT-MMIPs)最大吸附量为84.34mg/g;结合吸附动力学模型和吸附位点Scatchard方程对莠去津磁性分子印迹聚合物进行了吸附机理分析。对水库水样中存在的痕量莠去津进行了模拟检测分析,结果表明莠去津磁性分子印迹聚合物用于检测水样中残存的痕量莠去津是可行的。     

基于投影及优势度的不确定语言群决策方法

针对属性权重信息不完全的多粒度不确定语言多属性群决策问题,提出一种基于投影及优势度的群决策方法.该方法采用连续区间二元语义的有序加权调和平均(ITC-OWH)算子将多粒度不确定语言评价矩阵转化为二元语义决策矩阵,基于投影法构建目标规划模型,从而确定单个决策者的属性权重向量.在每个决策者之下,计算任意2个方案之间比较的综合属性优势度,根据综合优势度矩阵及决策者权重向量获得群体综合优势度矩阵,由各方案的总优势度获取方案的排序结果.最后,将提出的群决策方法应用到潜艇研制方案遴选问题中,验证了该方法的可行性与有效性.