对高校图书馆开展虚拟参考咨询服务的思考

实施虚拟参考咨询服务工作，是高校图书馆适应时代需要深化信息服务的必然途径。本文在虚拟参考咨询服务的特点基础上，对当前高校图书馆加强虚拟咨询服务管理，提高虚拟参考咨询服务水平提出了自己的见解。     

KF60AK型自翻车制造工艺分析

分析了KF60AK型自翻车的主要结构特点及倾翻原理,指出了KF60AK型自翻车制造难点、工艺方法及工艺措施。     

Food supply mechanisms for cold-water corals along a continental shelf edge

In recent years it has been documented that deep-water coral reefs of the species Lophelia pertusa are a major benthic habitat in Norwegian waters. However, basic information about the biology and ecology of this species is still unknown. Lophelia live and thrive under special environmental conditions of which factors such as temperature, water depth, water movement and food supply are important. The present work explores the hypothesis that Lophelia forms reefs in places where the encounter rate of food particles is sufficiently high and stable over long periods of time for continuous growth. This is done by relating the distribution of reefs with the results of numerical ocean modelling.Numerical simulations have been performed with an idealized bottom topography similar to what is found outside parts of the Norwegian coast. In the simulations the model is first forced with an along slope jet and then with an idealized atmospheric low pressure. The model results show that the encounter rates between the particles and the water layer near the seabed are particularly high close to the shelf break. This may indicate that many Lophelia reefs are located along the shelf edges because the supply of food is particularly good in these areas.A sensitivity study of the particle supply in the area close to the seabed for increasing latitude has also been done. This shows that the Ekman transport in the benthic layer tends to create a steady supply of food for benthic organisms near the shelf edge away from the equator.     

城市轨道交通项目投资/组织模式的制度绩效变迁分析

中国的城市轨道交通正处于单线、多线、网络的并存建设状态，其技术经济特性一方面直接影响投资制度设计的目标功能效用和成本；另一方面还引发了制度实施过程中的非预期功能，导致项目投资、组织模式之间出现某种内在关联和相互制约，于是模式的实施绩效沿时间轴发生变迁。考察了对应于两种项目投资结构的融资功能及其隐性成本；实证了一元投资／纵向一体化模式和一元投资／纵向“四分开”模式的平均成本曲线，指出在网络发展期，后者有向前者回归的趋势；另外，多元投资的单线经营特征使得业主有采用“代建制”的激励，但同时也引发了轨道网各单线项目之间的协调成本。最后说明投资／组织模式和城市轨道网全寿命周期自然属性的契合程度是决定其制度实施绩效的一个重要因素。     

软件无线电及其特性

软件无线电是未来无线通信发展的方向，由于其巨大的优越性和广泛的应用前景，已成为全球研究开发的热点。首先提出了软件无线电的定义，阐述了软件无线电基本特性及其相互之间关系，进而论述了系统效率与可重构性的关系以及软件体系结构等相关问题。     

炭素制品X射线图像的缺陷特征选择

针对炭素制品X射线检测图像的特点,对缺陷特征提取与选择技术进行了研究。为排除噪声干扰的影响,采用数学形态学和迭代阈值分割相结合的方法从原始图像中提取缺陷区域。在此基础上,从缺陷样本中提取19个特征值。为提高缺陷模式识别对各种噪声及干扰的鲁棒性,提出以特征组合分类能力数学模型为适合度函数,设计基于遗传算法的特征选择策略,实现了对缺陷原始特征量的优化选择。利用BP神经网络分类器及选择的特征值对缺陷进行模式分类。研究结果表明,所提出的选择方法可以用于缺陷的识别与分类。     

基于事务的概率标记数据包的IP回溯

针对Dos攻击,提出了一种改进的IP溯源技术PTPM(Probabilistic Transaction Packet Marking),利用事务把一个路由器的标记信息经由中间路由器传播到目的主机,最后根据收到的数据包重构攻击路径.这种方案大大减少了回溯数据包的个数.     

关于Sm∨Fn的边色数和点色数

并研究了m 1阶的星Sm和n 1阶的扇Fn的联图Sm∨Fn的边染色和点染色,得到了Sm∨Fn的边色数和点色数.     

A low-cost video-based pavement distress screening system for low-volume roads

This study investigates the use of consumer-grade video camera to develop a low-cost pavement distress screening system, with a particular focus on low-volume roads. Due to the oblique view of video data captured in the car front, existing crack detection algorithms that are tailor-made for nadir view cannot be used directly. Instead, we propose and develop a Video-based PAvement Distress Screening (VPADS) system, which includes an automatic data processing workflow by first defining a Region of Interest (RoI) through robust line fitting of the two side lanes. The pavement condition can be assessed within the RoI by implementing a multi-scale ridge detection filter followed by a boundary contour analysis. Since the proposed VPADS system is designed for preliminary screening purpose, each video image scene is examined if there exists any potential crack or distress feature(s). We tested the proposed system on video data collected for two low-volume roads (Highway 624 and 668) in Northern Ontario region, Canada. The overall accuracy of detecting crack and distress features yielded 80%. Instead of replacing traditional field inspection or high-end multi-sensor pavement evaluation system, the proposed VPADS system aims to provide a computer-aided screening solution for transportation authorities of a vast rural road/highway network and with limited inspection budget. The scope of the work can be further expanded by developing a crowdsensing inspection network built by any regular road user, who can also act as a data provider for the regional/municipal pavement distress screening system.     

非理想边缘电容器电容的分析

电容器是广为应用的电子器件之一.由于电容器的边缘不规则和具有明显的边缘效应,使电容的标称值与其实际值不符,常会引起无法预料的电容击穿等线路故障.通过对两类具有非理想边缘的矩形平行板电容器电容的分析,得出了具有较明显边缘效应的电容器电容的半定量结果和两板不严格平行的电容器电容的定量结果,指出了在实际应用中应注意的有关问题.