Network traces are a useful tool in understanding how users navigate the web. Knowing the sequence of pages that led a user to arrive at a malicious website can help researchers develop techniques to prevent users from reaching such sites. Nevertheless, inferring sound causation between HTTP requests is a challenging task. We present here methods for and considerations when inferring causation relationships betweenHTTP requests. We also introduce causation trees and terminology needed to model causal relationships between HTTP requests. Finally, we describe Gretel, our system that infers causation relationships, how we calibrated it, and our results on a sample control data set where ground truth was available.

关键词：网络跟踪；HTTP请求；控制数据样本

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We describe an approach to automatically generate a floor plan for the interior environment of a building using laser scan data. This floor plan is meant to accurately indicate the positions of walls within an area of interest in the building. The proposed algorithm separates the floors of a building scan, selects a representative sampling of wall scans for each floor, and triangulates these samples to develop a watertight representation of the walls for each of the scanned areas. Curves and straight line segments are fit to these walls, in order to mitigate any registration errors from the original scans. This method is not dependent on the scanning system and can successfully process noisy scans with non-zero registration error. Most of the processing is performed after a dramatic dimensionality reduction, yielding a scalable approach. We demonstrate the effectiveness of our approach on a three-story point cloud from a commercial building as well as on the lobby and hallways of a hotel.

关键词：激光扫描数据；平面图；建筑物

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Driver-assistance systems and fully autonomous vehicles could address the global challenges of traffic congestion and reduced road capacity. Although the field of autonomous transportation is growing rapidly, system complexity and cost have delayed progress. This project attempts to mitigate these issues through the development of a scale model robot that utilizes the sensors of smartphones for autonomous navigation and collision avoidance. Designing a model robotic system is simpler and more cost-e?ective than developing one for a full-sized vehicle. This project investigates the possibility of using smartphones sensors as a viable alternative to high-end, expensive sensors. The system utilizes the Orca Robotics software framework, which provides a library of modular and customizable components. The results from this study suggest that integrating smartphone sensors is much more challenging than using standalone devices. Further work is needed to confirm the feasibility of using these sensors. Ideally, as smartphones continue to improve in computational power and sensor accuracy, it will be possible to use them as integral components in autonomous systems.

关键词：自主运输；自主导航；避免碰撞；智能手机；传感器；机器人

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We present Sifter, an interface for browsing, comparing and analyzing large collections of image manipulation tutorials based on their command-level structure. Sifter first applies supervised machine learning to identify the commands contained in a collection of 2500 Photoshop tutorials obtained from theWeb.It then provides three different views of the tutorial collection based on the extracted command-level structure.

关键词：图像处理教程；基于网络的教程；命令级结构

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Recovering these same properties from a singleimage seems almost impossible in comparison——there are an infinite number of shapes, paint, and lights that exactly reproduce a single image. However, certain explanations are morelikely than others: surfaces tend to be smooth, paint tends to be uniform, and illumination tends to be natural. We therefore pose this problem as one of statistical inference, and define an optimization problem that searches for the most likely explanation of a single image.Ourmodel, which we call "SIRFS", can be viewed as a superset of several classic computer vision problems (shape-from-shading, intrinsic images, color constancy, illumination estimation, etc) and outperforms all previous solutions to those constituent problems. Recovering these same properties from a singleimage seems almost impossible in comparison——there are an infinite number of shapes, paint, and lights that exactly reproduce a single image. However, certain explanations are morelikely than others: surfaces tend to be smooth, paint tends to be uniform, and illumination tends to be natural. We therefore pose this problem as one of statistical inference, and define an optimization problem that searches for the most likely explanation of a single image.Ourmodel, which we call "SIRFS", can be viewed as a superset of several classic computer vision problems (shape-from-shading, intrinsic images, color constancy, illumination estimation, etc) and outperforms all previous solutions to those constituent problems.

关键词：计算机视觉问题；三维结构；二维结构

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To summarize, the goals of this thesis were to motivate analog synthesis by showing some examples of fully automatic generators and (2) to create a code framework for fully automatic standard cells that could be extended to other styles of layout.

关键词：模拟合成；代码框架；自动发电机；电池

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In this position paper, we present the research initiative for a precision timed (PRET) infrastructure, consisting of languages, compilers, and microarchitectures, where timing is a correctness factor. In particular, the timing semantics in models and programs must be preserved during compilation to ensure that the behavior of real systems complies with models. We also outline new research and design challenges present in such an infrastructure.

关键词：实体系统；硬件平台；编程语言；模型

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Increasing demand for information processing in the last 50 years has been largely satis ed by the steadily declining price and improving performance of microelectronic devices. Much of this progress has been made by aggressively scaling the size of semiconductor transistors and metal interconnects that microprocessors are built from. As devices shrink to the size regime in which quantum e ects pose signicant challenges, new physics may be required in order to continue historical scaling trends. A variety of new devices and physics are currently under investigation throughout the scienti c and engineering community to meet these challenges.

关键词：微电子设备；纳米；磁设备；信息处理；半导体晶体管

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In this work, we derive a new parallel communication-avoiding matrix powers algorithm for matrices of the form A = D+USV H, where D is sparse and USV H has low rank but may be dense. Matrices of this form arise in many practical applications, including power-law graph analysis, circuit simulation, and algorithms involving hierarchical (H) matrices, such as multigrid methods, fast multipole methods, numerical partial di erential equation solvers, and preconditioned iterative methods.

关键词：移动数据；并行通讯；并行矩阵

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Android provides tools to enable rich interaction, but if developers do not know how to use them correctly, they will not use them securely. In this dissertation, we examine how mobile applications interact with each other and their environment. We uncover threats to application security due to developer confusion and general misuse of the features provided by the mobile platform. Specifically, we perform an in-depth analysis of how Android applications interact with each other through inter-process communication mechanisms, how they interact with system resources through Android permissions, and how they interact with web content through WebViews. We build static analysis tools to identify vulnerable applications and measure the prevalence of the vulnerabilities. Through automated and manual analysis, we identify patterns that illustrate how developers misuse these features and make their application vulnerable to attack. We further provide platform-level, API-level, and design-leve solutions to help developers and platform designers build secure applications and systems.

关键词：移动应用；安全性；应用程序；安卓

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