A new calibration model of camera lens distortion

Lens distortion is one of the main factors affecting camera calibration. In this paper, a new model of camera lens distortion is presented, according to which lens distortion is governed by the coefficients of radial distortion and a transform from ideal image plane to real sensor array plane. The transform is determined by two angular parameters describing the pose of the real sensor array plane with respect to the ideal image plane and two linear parameters locating the real sensor array with respect to the optical axis. Experiments show that the new model has about the same correcting effect upon lens distortion as the conventional model including all the radial distortion, decentering distortion and prism distortion. Compared with the conventional model, the new model has fewer parameters to be calibrated and more explicit physical meaning.     

Visualizing transport structures of time-dependent flow fields

This article focuses on the transport characteristics of physical properties in fluids-in particular, visualizing the finite-time transport structure of property advection. Applied to a well-chosen set of property fields, the proposed approach yields structures giving insights into the underlying flow's dynamic processes.     

Consistency-driven data quality management of networked sensor systems

With more and more real deployments of wireless sensor network applications, we envision that their success is nonetheless determined by whether the sensor networks can provide a high quality stream of data over a long period. In this paper, we propose a consistency-driven data quality management framework called Orchis that integrates the quality of data into an energy efficient sensor system design. Orchis consists of four components, data consistency models, adaptive data sampling and process protocols, consistency-driven cross-layer protocols and flexible APIs to manage the data quality, to support the goals of high data quality and energy efficiency. We first formally define a consistency model, which not only includes temporal consistency and numerical consistency, but also considers the application-specific requirements of data and data dynamics in the sensing field. Next, we propose an adaptive lazy energy efficient data collection protocol, which adapts the data sampling rate to the data dynamics in the sensing field and keeps lazy when the data consistency is maintained. Finally, we conduct a comprehensive evaluation to the proposed protocol based on both a TOSSIM-based simulation and a real prototype implementation using MICA2 motes. The results from both simulation and prototype show that our protocol reduces the number of delivered messages, improves the quality of collected data, and in turn extends the lifetime of the whole network. Our analysis also implies that a tradeoff should be carefully set between data consistency requirements and energy saving based on the specific requirements of different applications.     

Scanning Depth of Route Panorama Based on Stationary Blur

This work achieves an efficient acquisition of scenes and their depths along long streets. A camera is mounted on a vehicle moving along a straight or a mildly curved path and a sampling line properly set in the camera frame scans the 1D images over scenes continuously to form a 2D route panorama. This paper proposes a method to estimate the depth from the camera path by analyzing a phenomenon called stationary blur in the route panorama. This temporal blur is a perspective effect in parallel projection yielded from the sampling slit with a physical width. We analyze the behavior of the stationary blur with respect to the scene depth, vehicle path, and camera properties. Based on that, we develop an adaptive filter to evaluate the degree of the blur for depth estimation, which avoids error-prone feature matching or tracking in capturing complex street scenes and facilitates real time sensing. The method also uses much less data than the structure from motion approach so that it can extend the sensing area significantly. The resulting route panorama with depth information is useful for urban visualization, monitoring, navigation, and modeling.     

抛物问题Mortar有限元的瀑布型多重网格法

对抛物问题的全离散格式采用Mortar型有限元逼近,构造了相应的瀑布型多重网格法,证明了该方法的最优性.     

基于动态融合蚁群遗传算法的医学图像配准

将基于动态融合的蚁群遗传算法作为一种新的图像配准优化算法应用在多模医学图像配准中。该算法以互信息作为相似性测度,生成初始信息素分布,采用蚁群算法搜索最优变换参数,其中动态融合策略提高了混合算法的搜索效率。仿真实验结果表明,该算法有效地避免信息函数的局部极值,减少大量重复运算,提高了配准的效率,配准结果具有良好的稳定性。     

一种基于SOADL的Web服务合成方法

服务合成是面向服务的软件开发中的一个重要开发活动.探讨了体系结构设计和服务合成之间的关系,提出了一种基于体系结构的Web服务合成方法.通过自动发现服务以及自动生成过程代码和部署代码,可以将SOADL的体系结构模型转化为一个可执行的BPEL组合系统,来实现Web服务的合成.与其它服务合成方法相比,合成方法可以更好地实现从设计到实现的平滑过渡,提高合成的效率和保障合成后系统与体系结构模型之间的可跟踪性.     

粘连细胞分割算法的研究与实现

以粘连细胞分割为例,提出了一种基于分水岭算法的图像分割算法.算法对分水岭分割之前的距离变换和求种子点进行了改进,得到了较好的分割效果.实验证明,该算法较好地完成了粘连细胞的分割任务.     

基于ASP.NET的“五线”报修管理系统设计与实现

讨论利用ASP.NET和ADO.NET技术开发的五线(网络、电视、电话、广播、监控)报修管理系统.借助网络使系统实现了无人职守状态下的报修记录追加、修改、删除、浏览、查询、统计等功能,提高了报修、维护、维修的工作效率.同时简要讨论了ASP.NET的优势,并介绍系统的开发原理、功能结构.