Validating for Liveness in Hidden Adversary Systems

Multi-stream interactive systems can be seen as “hidden adversary” systems (HAS), where the observable behaviour on any interaction channel is affected by interactions happening on other channels. One way of modelling HAS is in the form of a multi-process I/O automata, where each interacting process appears as a token in a shared state space. Constraints in the state space specify how the dynamics of one process affects other processes. We define the “liveness criterion” of each process as the end objective to be achieved by the process. The problem now for each process is to achieve this objective in the face of unforeseen interferences from other processes. In an earlier paper, it was proposed that this uncertainty can be mitigated by collaboration among the disparate processes. Two types of collaboration philosophies were also suggested: altruistic collaboration and pragmatic collaboration. This paper addresses the HAS validation problem where processes collaborate altruistically.     

Complex Task Allocation in Mobile Surveillance Systems

In mobile surveillance systems, complex task allocation addresses how to optimally assign a set of surveillance tasks to a set of mobile sensing agents to maximize overall expected performance, taking into account the priorities of the tasks and the skill ratings of the mobile sensors. This paper presents a market-based approach to complex task allocation. Complex tasks are the tasks that can be decomposed into subtasks. Both centralized and hierarchical allocations are investigated as winner determination strategies for different levels of allocation and for static and dynamic search tree structures. The objective comparison results show that hierarchical dynamic tree task allocation outperforms all the other techniques especially in complex surveillance operations where large number of robots is used to scan large number of areas.     

基于智能网络的视频监控系统分析

近些年,随着我国经济的飞速发展、科技水平的快速提升,国内安防领域相继开发、研制、推出了多种器械、设备、系统。其中,视频监控系统的发展与应用,已由以往创痛的VCR模拟系统、NVR/DVR半数字化系统,逐步改进、过度为全数字化视频监控系统,将传统被动的接收模式转化为主动的监控、分析模式,其主要是建立在电子信息网络系统的基础上,通过综合应用网络摄像机、多功能模块、视频服务器来实现。本文就基于智能网络的视频监控系统作简要的分析、探讨。     

The Lazy Adversary Conjecture Fails

In the context of competitive analysis of online algorithms for the k-server problem, it has been conjectured that every randomized, memoryless online algorithm exhibits the highest competitive ratio against an offline adversary that is lazy, i.e., that will issue requests forcing it to move one of its own servers only when this is strictly necessary to force a move on the part of the online algorithm. We prove that, in general, this lazy adversary conjecture fails. Moreover, it fails in a very strong sense: there are adversaries which perform arbitrarily better than any other adversary which is even slightly "lazier."     

Windows监控系统的串行通信部分设计

文中就一个典型的基于Windows的监控系统串行通信部分的设计实例,详细分析了系统中串行通信的实现,高精度定时器的实现以及软件的流程设计方面的问题与应用经验。     

智能监控系统跟踪技术研究

根据小区环境的复杂背景、光照变化以及经济成本等因素,开发了智能报警监控系统,自动控制云台转动,能保证目标在可监视范围之内.针对背景混淆下的跟踪难点,为准确预测目标位置,提出基于谱直方图的特征提取算法进行目标检测,并引入Kalman滤波器预测目标位置的跟踪算法.谱直方图将图像转移到频域进行统计,减少了颜色以及噪声等因素的干扰.仿真实验证明,系统可以保证视频监控的实时性以及自动跟踪的准确性,并且有效地节约了系统开发的经济成本.     

社会感知计算:概念、问题及其研究进展

普适计算技术的发展极大地丰富和增强了人类获取数据的途径和能力,如何利用这些感知数据,理解人类的社会行为与活动,实现计算“以人为中心”并为社会服务的目标,是当前信息领域的重要问题.本文介绍了计算机科学领域的一个刚刚兴起的研究主题——社会感知计算.社会感知计算旨在通过人类生活空间日益部署的大规模多种类传感设备,实时感知识别社会个体的行为,分析挖掘群体社会交互特征和规律,辅助个体社会行为,支持社群的互动、沟通和协作.论文讨论了社会感知计算的概念、起源、模型和主要研究问题,综述了社会感知计算典型系统与应用、数据感知、行为与交互分析、社会理论与规律验证以及社会交互高效支持等方面的研究进展.     

无线电监测系统与网络的分析与设计

网络构建是现代无线电监测的趋势。结合长江沿岸地形特点和监测覆盖范围,描述了如何构建覆盖水上重点区域的无线电监测网络体系的基本模型,并对长江沿岸无线电监测系统的功能进行了分析和设计。系统的主要任务是对违规用户的监听、测向、定位和抓获,利用固定监测中心、监测站监测和发现违规用户信号,井协调车载移动站或船栽便携设备快速逼近实现查处。     

Cache Aware Pre-Runtime Scheduling

We present a novel pre-runtime scheduling method for uniprocessors which precisely takes the effects of task switching on the processor cache into consideration. Tasks are modelled as a sequence of non preemptable segments with precedence constraints. The cache behavior of each task segment is statically determined by abstract interpretation. For the sake of efficiency, the scheduling algorithm uses a heuristically guided search strategy. Each time a new task segment is added to a partial schedule, its worst case execution time is calculated based on the cache state at the end of the preceding partial schedule.     

Structure Aware Visual Cryptography

Visual cryptography is an encryption technique that hides a secret image by distributing it between some shared images made up of seemingly random black‐and‐white pixels. Extended visual cryptography (EVC) goes further in that the shared images instead represent meaningful binary pictures. The original approach to EVC suffered from low contrast, so later papers considered how to improve the visual quality of the results by enhancing contrast of the shared images. This work further improves the appearance of the shared images by preserving edge structures within them using a framework of dithering followed by a detail recovery operation. We are also careful to suppress noise in smooth areas.     

Geometry Aware Tori Decomposition

This work presents a shape decomposition algorithm to partition a complex high genus surface into simple primitives, each of which is a torus. First, using a novel iterative algorithm, handle and tunnel fundamental cycles on the surface are progressively localized. Then, the problem of computing the splitting cycles that produce such a tori decomposition is posed as a min‐cut problem on the mesh's dual graph with earlier computed tunnels as source and target. The edge weights for the min‐cut problem are designed for the cut to be geometry‐aware. We present an implementation and demonstrate the results of our algorithm on numerous examples.     

Curvature Aware Fundamental Cycles

We present a graph algorithm to find fundamental cycles aligned with the principal curvature directions of a surface. Specifically, we use the tree‐cotree decomposition of graphs embedded in manifolds, guided with edge weights, in order to produce these cycles. Our algorithm is very quick compared to existing methods, with a worst case running time of O(n log n+gn) where n is the number of faces and g is the surface genus. Further, its flexibility to accommodate different weighting functions and to handle boundaries may be used to produce cycles suitable for a variety of applications and models.     

基于GIS的敌情信息库的研究

潜艇兵力的指挥控制需要一个具有对海量的GIS数据和属性数据进行存储、索引、查询能力的敌情信息库。本文提出一种基于Oracle数据库及其扩展包OracleSpatial信息库的解决方案,并给出相应例子,结果显示这种方案相当灵活实用。     

Adversary lower bounds for nonadaptive quantum algorithms

We present two general methods for proving lower bounds on the query complexity of nonadaptive quantum algorithms. Both methods are based on the adversary method of Ambainis. We show that they yield optimal lower bounds for several natural problems, and we challenge the reader to determine the nonadaptive quantum query complexity of the “1-to-1 versus 2-to-1” problem and of Hidden Translation.In addition to the results presented at Wollic 2008 in the conference version of this paper, we show that the lower bound given by the second method is always at least as good (and sometimes better) as the lower bound given by the first method. We also compare these two quantum lower bounds to probabilistic lower bounds.     

数码相机监控系统的研究与开发

近年来,在视频采集的应用中,数码相机监控系统以其高分辨率、方便、快捷、处理软件丰富以及高性能比等优点,愈来愈受到人们的青睐。文章将围绕数码相机监控系统软、硬件的设计和开发展开论述。     

Diagnostics and Surveillance Methods in Nuclear Systems for Real-Time Applications

This paper reviews some process signal analysis and representation methods that can be used during reactor operation such that they are suitable for real-time applicatons. All listed methods have been tested on data from operating plant. The objective is to detect and interpret changes in the plant or core status at an early stage, such that appropriate measures can be taken immediately. The methods that are discussed and demonstrated in the paper can be divided into two categories. The first is the use of fast and intelligent computing methods such as neural networks and fast wavelet transform, in combination with a diagnostic unfolding procedure which would be computationally rather demanding with traditional methods. The second type is based on direct representation of the system state through visualization of large complex data, showing the space–time behavior of the system. This latter is not associated with any unfolding procedure, it uses only a moderate signal preprocessing for filtering out redundant information, but otherwise showing the process status directly. Such methods have been made possible with the development of powerful computer visualization techniques. The potentials represented by this second alternative do not seem to have been explored fully yet in reactor diagnostics. Methods corresponding to both categories will be demonstrated and discussed in the paper.     

Online QoS Optimization Using Service Classes in Surveillance Radar Systems

Many application level qualities are functions of available computation resources. Recent studies have handled the computation resource allocation problem to maximize the overall application quality. However, such QoS problems are fundamentally multi-dimensional optimization problems that require extensive computation. Therefore, online usage of optimization procedures may significantly reduce the computation resource available for applications. This raises the question of how to best use the optimization procedures for dynamic real-time task sets. In dynamic real-time systems, it is important to improve the performance by re-allocating the resources adapting to dynamic situations. However, the overhead of changing task parameters (i.e., algorithms and frequencies) for resource re-allocation is non-negligible in many applications. Thus, too frequent change of resource allocation may not be desirable. This paper proposes a method called service classes configuration to address the QoS problem with dynamic arrival and departure of tasks. The method avoids online usage of optimization procedures by offline designing templates (called service classes) of resource allocation, which will be adaptively used depending on online situations. The service classes are designed by best trading-off the accuracy of dynamic adaptation against the overhead of resource re-allocation. A simplified radar application is used as an illustrative example.     

Infrastructure Aware Scientific Workflows and Infrastructure Aware Workflow Managers in Science Gateways

The workflow interoperability problem was successfully solved by the SHIWA project if the workflows to be integrated were running in the same grid infrastructure. However, in the more generic case when the workflows were running in different infrastructures the problem has not been solved yet. In the current paper we show a solution for this problem by introducing a new type of workflow called infrastructure-aware workflow. These are scientific workflows extended with new node types that enable the on-the-fly creation and destruction of the required infrastructures in the clouds. The paper shows the semantics of these new types of nodes and workflows and also how they can solve the workflow interoperability problem. The paper also describes how these new type of workflows can be implemented by a new service called Occopus, and how this service can be integrated with the existing SHIWA Simulation Platform services like the WS-PGRADE/gUSE portal to provide the required functionalities of solving the workflow interoperability problem.