基于车载激光扫描数据的城区道路自动提取

提取准确的道路信息对城市规划和数字城市制图具有重要意义。利用高密度车载激光扫描数据,针对无法以路沿作为道路边界的情况,提出一种基于边缘线检测的道路自动提取方法。先利用平面检测算法对分段后的路面完成粗提取,在此基础上,分析道路边缘线与相邻两侧路面在激光反射强度与几何性质上的差异,通过设定合理阈值提取边缘线上的点云,最后对离散边缘点进行曲线拟合完成道路精提取。利用实际获取的城区车载点云数据验证表明,该方法提取道路的正确度、完整度和提取质量等均高于90%,特别是对无明显路沿的道路,可有效识别出道路边缘线。     

网络安全扫描工具的分析与设计

主要分析了当前流行的扫描工具,并设计出一个简单模型.     

Centralized vs. Decentralized Models in Interlibrary Loan Access

ABSTRACT

In fall 1997, the University of Washington Bothell Library piloted a home-grown Electronic Reserves project to better meet the needs of its non-traditional population, consisting largely of returning, working, and/or commuting students. As the number of students commuting from greater distances increased, the need to provide remote access to course materials 24-hours a day became essential. Since no additional funding was received, the pilot began with only four classes. This enabled librarians to become familiar with the technology without being overwhelmed by demand. In-class demonstrations were provided, and quarterly surveys were distributed to students and faculty participating in the project. Results were analyzed over several quarters to determine the benefits to students and faculty. By fall 1998, 33 courses or 80% of reserves were available electronically. Issues that developed from the pilot included: (1) increased printing in the library and computer labs, (2) development of training classes for students; and (3) staff reorganization to provide the service.     

Interlibrary Loan Options With Digital Equipment

Technology has changed over time for interlibrary loan; digital equipment now gives opportunities to deliver requests without damaging rare or fragile materials. Examples of the equipment are cameras, flat bed scanners, form feed scanners, iPhones, iPads, handheld scanning wands, microreel scanners, and microfiche scanners. In this article, we will take a look at uses for copying rare books and uses of digital equipment to fill interlibrary loan requests.     

振镜扫描系统对熔石英损伤的修复

利用CO2激光器的振镜扫描修复装置对较大尺寸（≥200μm）的熔石英损伤点进行了定点修复,比较了功率和扫描速度对修复坑形貌的影响。修复后的面型大小以及深度随激光功率增加而增加,随激光扫描速度的提高而减小。先用较低功率作用,再用较高功率作用可以有效减少气泡的产生。利用激光功率缓慢递增多次作用的修复方法,可以消除烧蚀。修复后阈值基本上可以达到损伤前的水平,达到了提升损伤阈值的目的。     

单分子操纵与调控

由于具备在空间和能量尺度的高分辨表征能力以及纳米局域探针特点,扫描隧道显微术已经成为近年来对单分子体系进行空间、结构操纵和物理、化学性质调控的重要工具。它可以操纵单分子及其组元在材料表面进行各种运动模式乃至化学反应,并通过电致等外场效应调节单分子体系的量子态,从而在新型材料探索、纳米器件设计、化学反应机理研究与控制等领域具有极大的应用潜力。     

Intelligent agent systems for executive information scanning,filtering and interpretation: Perceptions and challenges

Using intelligent agent-based systems to support information processing for executives has not been significantly advanced in both theory and practice. Research into this field tends to focus more on technical aspects than on social perspective. When executives are faced with increasing information availability and uncertainty in the business environment, using intelligent agent-based systems to enhance executives’ information processing capability appears both an opportunity and a necessity. This study examines UK executives’ perceptions of intelligent agent-based systems for information scanning, filtering, interpretation and alerting. The study follows a deductive research design, i.e. hypothesis formulation and testing from the user’s perspective. Qualitative data was collected through focus groups and interviews with executives in the UK. The study produces rich evidence that challenges preconceptions of using agent-based information processing system by executives. The findings develop insight into executives’ behavior in information processing, which has implications for intelligent system developers and organizational information processing practice.     

Dynamic identification of historic masonry towers through an expeditious and no-contact approach: Application to the “Torre del Mangia” in Siena (Italy)

The paper presents a synergic and multidisciplinary approach where laser scanner survey, radar interferometric monitoring and finite element (FE) numerical modelling are used for expeditious and no-contact dynamic identification of monumental masonry towers. The methodology is applied to a real case of great historical interest: the “Torre del Mangia” (Mangia's tower) in Siena (Italy). The tower geometry was acquired through Terrestrial Laser Scanning (TLS) techniques. The tower oscillations were detected using an interferometric radar in “Piazza del Campo”, the square facing the Mangia's Tower, along three alignments, and movement of the structure at several heights were recorded. A FE model, built on the basis of the geometry acquired through the TLS, was used to interpret and verify the physical meaning of the experimental results. Through the discussion of the case study, the paper shows that the proposed approach can be considered as an effective and expeditious method for assessing the dynamic behavior of monumental buildings (and to plan interventions) on territorial scale.     

Earthquakes and ancient leaning towers: Geodetic monitoring of the bell tower of San Benedetto Church in Ferrara (Italy)

In May–June 2012, several seismic events took place in the Po River Plane in northern Italy, with a maximum magnitude of M_W 5.86 (M_L 5.9)] and the epicentre located about 32 km from the centre of Ferrara. Many historical buildings were seriously damaged and others showed marked deformations or differential settlements. Therefore, it was necessary to place many of them under monitoring, using fast and safe measurement techniques to quickly obtain accurate information on ongoing structural deformation. This paper presents the case study of the bell tower of San Benedetto Church in Ferrara (17th century), which was already under monitoring at the time of the earthquake because of its remarkable leaning angle. Immediately after the seismic events, monitoring of the bell tower was repeated. Digital levelling indicated a marked differential settlement of the foundations with regard to the trend of secular movement, while terrestrial laser scanning (TLS) revealed a significant increase of the inclination of the tower's axis, confirming the results from levelling and showing good integration of both monitoring techniques.     

Multi-Agent系统基于优先级的负载均衡任务调度模型*

从企业收集、监测互联网信息的实际需求出发，介绍基于Multi-Agent的分布式信息采集系统的结构模型；重点阐述中心控制Agent在组间层次上、调度Agent在组内层次上基于优先级的任务调度算法；为达到系统中运行任务Agent的各节点主机负载均衡，给出调度Agent与任务Agent间的组内协商机制；对系统原型的测试结果表明，基于优先级的负载均衡任务调度模型的正确性与有效性。