视频摘要技术综述

基于内容的视频分析,检索与索引技术是当前多媒体领域研究的热点之一,视频要主要分为两类,静态视频要模式（视频略览）,包括基于MPEG-1/2的关键帧表示和MPEG-4的关键对象表示;动态视频要模式（视频梗概）,包括视频概述和精彩片段,该介绍了视频要的新方向——基于情感,心理学等视频要模型。     

双目汇聚摄像系统深度信息测量研究

针对双目平行摄像系统中的盲区问题,首先提出了双目汇聚摄像系统的数学模型。然后基于这一数学模型,采用角点检测方法和外极线约束条件分别进行对应点提取和匹配,推导出双目汇聚摄像系统的物体深度计算公式。最后通过对双目汇聚模型的计算机仿真,验证算法的有效性。     

H.264/AVC及其在IP网络中的应用

H．264是一个新的低速率视频压缩标准,主要由视频编码层VCL和网络提取层NAL组成、该文研究在供时传输协议下,H264在IP网络中的应用。     

基于神经网络的汽车车图象自动识别

提出了一种利用前向三层神经网络及计算机视觉技术对汽车车型进行自动识别的方法,包括汽车车型图象的分割,特征提取以及基于前向三层神经网络的自动识别和分类,文中的所有算法均在５８６／１３３微机上实现,识别和分类效果良好。     

The entry point of face recognition: Evidence for face expertise.

Previous studies have shown that experts (e.g., birdwatchers) are as fast to recognize objects at subordinate levels of abstraction (e.g., robin) as they are to recognize the same object at the basic level (e.g., bird). As a test of face expertise, the current study found that adults identify faces more frequently (Experiment 1) and as quickly (Experiment 2) at the subordinate level (e.g., Bill Clinton) as at the basic level (e.g., human). Whereas brief presentation (75 ms) impaired subordinate-level recognition of nonface objects, it did not impair the subordinate level recognition of faces (Experiment 3). Finally, in an identity-matching task, subordinate-level primes facilitated the matching responses of faces but not nonface objects (Experiment 4). Collectively, these results indicate that face expertise, like expert object expertise, promotes a downward shift in recognition to more subordinate levels of abstraction. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

基于服务流网模型的网格应用细化与抽象

针对实现资源共享和协同工作的网格技术应用研究与发展现状,文章结合Petri网理论、工作流及WEB服务技术,定义了服务流网(ServerFlownet,SF-net)模型,并重点对基于服务流网模型的网格应用细化与抽象进行了研究,最后以军事信息网格环境下作战过程为例加以说明。     

抽象事件的完备逻辑时钟

调试分布式应用系统要比调试顺序程序困难得多,原因之一是分布式应用系统要比顺序程序复杂得多.为了处理分布式应用系统的复杂性,提出了对分布式应用系统的事件进行抽象的调试方法,这种方法让用户从不同的层次观察分布式应用系统的行为.在对分布式应用系统进行调试和抽象时,抽象事件（事件集）之间的先于关系起着重要作用,而逻辑时钟用来确定事件间的先于关系.文章给出了一种计算抽象事件的完备逻辑时钟的方法,这种方法比以往的方法所占存储量小,而且计算速度快.另外,文中还给出了算法的正确性证明.     

Reactive Modules

We present a formal model for concurrent systems. The model represents synchronous and asynchronous components in a uniform framework that supports compositional (assume-guarantee) and hierarchical (stepwise-refinement) design and verification. While synchronous models are based on a notion of atomic computation step, and asynchronous models remove that notion by introducing stuttering, our model is based on a flexible notion of what constitutes a computation step: by applying an abstraction operator to a system, arbitrarily many consecutive steps can be collapsed into a single step. The abstraction operator, which may turn an asynchronous system into a synchronous one, allows us to describe systems at various levels of temporal detail. For describing systems at various levels of spatial detail, we use a hiding operator that may turn a synchronous system into an asynchronous one. We illustrate the model with diverse examples from synchronous circuits, asynchronous shared-memory programs, and synchronous message-passing protocols.     

焦油中精蒽／咔唑提取工艺的评述

介绍了近年来从焦油中提取精蒽和咔唑产品工艺的现状,并对两种常用工艺从工艺方案合理性、技术先进性及经济技术三方面做了较详尽的比较分析和综合评述。提出结晶－蒸馏法是目前提取精蒽／咔唑技术先进、工艺合理、有发展前途的工艺。同时提出了对现有溶剂洗涤法制取精蒽和咔唑工艺状况的改进设想。     

Identifying and alleviating low flows in regulated rivers: the case of the Rivers Bulbourne and Gade,Hertfordshire, UK

This paper examines evidence for the occurrence and causes of low flows, and strategies for their mitigation, in two regulated, chalk‐fed streams. The rivers occupy adjacent catchments of similar topography, have long histories of water exploitation and land‐use change, and are subject to conflicting demands of water resource development and increased pressure for environmental improvement. In one case, a strategy of low‐flow mitigation based upon reduced groundwater abstraction has been proposed. Although flows are shown to be declining through time, and low flows are more common over the last decade, analysis of rainfall records and groundwater levels produce inconclusive evidence for the causes of low flows. Despite their natural similarities, the catchments are shown to have very different sensitivities to low flow. When concentrating upon quantity of low flow, the River Gade appears to be most compromised, but when consideration is taken of water quality, the Bulbourne is more severely affected. An examination of catchment changes over a longer time period provides the best rationale for these sensitivities and contrasts. The study illustrates the potential danger of starting with a solely climatic–hydrological perspective to low flows which then progresses to a hydrological ‘solution’. Consideration of catchment land‐use history, and of the importance of water quality, suggest limited applicability of reduced abstraction in mitigating low‐flow problems in these kinds of environments. The study reinforces calls for further studies of groundwater–surface water interaction as essential inputs to appropriate and sustainable water resource management strategies. Copyright © 2000 John Wiley & Sons, Ltd.