This is particularly true in urban environments where tall buildings block satellite view for GPS, and distortions in Earth’s magnetic field from power lines adversely affect compass readings.In this thesis, we describe an image based  localization  algorithm  for  estimating  the  pose  of  cell  phones  in  urban  environments.  This  is motivated by the fact that most of today’s cell phones are equipped with cameras whose imagery can be matched against an  image database for  localization purposes.

关键词：移动设备；手机；定位算法；GPS

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The National Research Council has highlighted the importance of the changeover to multicore architectures on software performance. They predict strong economic impacts for users in industry as a result of the change. This thesis is part of a larger research project that aims to quantify those effects. The main contribution of this thesis is to build a measure of how well firms can take advantage of multicore chips, which is a key ingredient in addressing this important problem. This measure is built up using unique data on firm software usage from the marketing firm Harte Hanks, and combining it with results from the Berkeley Software Parallelism Survey – a survey of parallelism experts run for this thesis. Alternative formulations for creating this parallelism measure are also discussed and evaluated, with the reasons for choosing the main formulation clearly expressed. Finally, this thesis highlights the limitations of this measure and discusses the other on-going initiatives that are underway to address them. This thesis also makes a supplemental contribution by highlighting a new case study detailing the impact of the changeover to multicore. It also reports additional results from the Berkeley Software Parallelism Survey that may be of interest to those assessing the presence of different types of parallelism or different computational motifs in mainstream software programs.

关键词：软件性能；转换多核；芯片；市场营销；并行度

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We present a mobile photo editing application— CrowdBrush, which uses Google Android as front-end platform and Amazon Mechanical Turk as back-end platform. As there are increasingly more images were captured by smart phone these days, providing photo manipulation functions on the mobile phone directly become very important for better user experience.Our system aims at providing more advanced photo manipulation features by uploading a user’s image to our backend server, having workers on the internet help to process the image, and then sending the processed result back to the mobile phone.

关键词：CrowbBrush；图片编辑软件；计算机视觉技术；自动全景

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In this thesis, we present two new deployment models for middleboxes which offer new capabilities for middlebox usage as well as new business models for middlebox deployment. Netcalls is an extension to the Internet architecture that allows end host applications to invoke and configure middleboxes in any network their traffic traverses; for example, we present a web server that invokes inter-domain DDoS defense when it detects that it is under attack. APLOMB is a system that allows enterprise networks (as well as individual end hosts) to tunnel their traffic to and from a cloud service that applies middlebox processing to their traffic, avoiding the costly and management-intensive burden of administering middleboxes in a local network. Netcalls and APLOMB allow ISPs and cloud providers (respectively) to monetize their deployment of middleboxes by offering them as a service to third-party clients; all the while presenting new capabilities, in the case of netcalls by enabling application interaction and in the case of APLOMB by providing better scalability and easier management. We discuss both of these proposals and their benefits in detail; we then discuss challenges and opportunities towards their deployment and adoption.

关键词：互联网；云计算；加工服务；体系结构

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New architectures require careful examination of security properties in order to assess and contain new threats. In light of this, emerging technologies, such as web APIs, medical devices, and applications on mobile phones, are a new security landscape that has recurring security problems. We develop new techniques to analyze these applications for security vulnerabilities, utilizing techniques including: dynamic symbolic execution, binary analysis and reverse engineering, and wide scale application comparison and classification. We develop Kudzu, a system for symbolic execution of JavaScript, and use it to evaluate a wide variety of JavaScript applications in order to find client-side validation vulnerabilities.

关键词：新兴架构；安全漏洞；新兴技术；web APIs；医疗器械；移动应用程序

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Current smartphone platforms provide ways for users to control access to information about their location. For instance, on the iPhone, when an application requests access to location information, the operating system asks the user whether to grant location access to this application. In this paper, we study how users are using these controls. Do iPhone users allow applications to access their location? Do their decisions di er from application to application? Can we predict how a user will respond for a particular application, given their past responses for other applications?

关键词：位置信息；隐私；用户行为；应用程序；智能手机

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The non-determinism in concurrent and distributed systems and the unreliability of the hardware environment in which they operate can result in defects that are hard to find and understand. In this thesis, we have developed tools and techniques to augment testing to enable it to quickly find and reproduce important bugs in concurrent and distributed systems.

关键词：分布式计算；程序分析；硬件环境；并发云系统；分布式系统

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We present a system for learning nouns directly from images, using probabilistic predictions generated by visual classifiers as the input to Bayesian word learning, and compare this system to human performance in an automated, large-scale experiment. The system captures a significant proportion of the variance in human responses. Combining the uncertain outputs of the visual classifiers with the ability to identify an appropriate level of abstraction that comes from Bayesian word learning allows the system to outperform alternatives that either cannot deal with visual stimuli or use a more conventional computer vision approach.

关键词：机器学习系统；贝叶斯模型；视觉刺激

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This dissertation addresses a series of graph problems inspired by the computational issues with face with the Internet, a massive distributed network of autonomous agents. There are several levels to this problem. From a systems perspective, what can we do to facilitate computation over massive graphs? From a modeling perspective, what do natural graphs look like and what features are useful? From a game theoretic perspective, the graphs often represent individuals or systems with their own goals and agendas. Can we understand how these systems compete and when these competitions are fair or can be manipulated? These questions are addressed. For the first, we consider the problem of streaming graph partitioning and show it is feasible. For the second, we study the joint degree distribution of a graph and show it is combinatorially easy to work with. Finally, we address questions about tournament design and manipulation.

关键词：互联网；图论算法；分布式网络图

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Long range dependence refers to stochastic processes for which correlations persist at much longer time scales as compared to traditional models. For such processes the central limit theorem does not in general hold, and the smoothing e ect of the law of large numbers takes more time to settle in. Such phenomena have been observed in many di erent elds including nancial time series, DNA sequences, network traffic and variable bit-rate video. The bursty nature and persistent correlation structure of long range dependent processes make them tough to control and predict in practice, and tough to analyze in theory. In this thesis we look at the origins of long range dependence through the use of Markov models.

关键词：长距离依赖；随机过程；可变比特率

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