Parallel algorithms for sparse matrix-matrix multiplication typically spend most of their time on inter-processor communication rather than on computation, and hardware trends predict the relative cost of communication will only increase. Thus, sparse matrix multiplication algorithms must minimize communication costs in order to scale to large processor counts.

关键词：通信优化；并行算法；稀疏矩阵乘法；通信成本；处理器

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This paper discusses the use of the Ptides model of computation as a coordination language for the design of deterministic, event-driven, real-time, distributed embedded systems. Specifically, the paper shows how the use of synchronized clocks in the context of Ptides enables explicit, platform independent speci cation of functionality and timing. From this speci cation, we generate code for two target platforms: Renesas and XMOS. The generated code includes a lightweight operating system which performs scheduling, I/O and network handling as well as application speci c tasks.

关键词：Ptides模型；估计；操作系统；网络处理；代码

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This report has presented two software tools implemented in MATLAB to simulate a 13.6 g ornithopter in the sagittal plane and horizontal plane. Each of these simulations were compared totrueight data colected using a Vicon motion capture system to determine their accuracy.

关键词：飞行；模拟；扑翼飞机；MATLAB；软件

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Advertising is a critical part of the Android ecosystem| many applications use one or more advertising services as a source of revenue. To use these services, developers must bundle third-party, binary-only libraries into their applications. In this model, applications and their advertising libraries share permissions. Advertising-supported applications must request multiple privacy-sensitive permissions on behalf of their advertising libraries, and advertising libraries receive access to all of their host applications' other permissions. We conducted a study of the Android Market and found that 49% of Android applications contain at least one advertising library, and these libraries overprivilege 46% of advertising-supported applications. Further, we nd that 56% of the applications with advertisements that request location (34% of all applications) do so only because of advertisements. Such pervasive overprivileging is a threat to user privacy. We introduce AdDroid, a privilege separated advertising framework for the Android platform. AdDroid introduces a new advertising API and corresponding advertising permissions for the Android platform. This enables AdDroid to separate privileged advertising functionality from host applications, allowing applications to show advertisements without requesting privacy-sensitive permissions.

关键词：广告商；应用程序

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In this paper, we demonstrate a connection between Storvik's lter and a Kalman lter in parameter space and establish more general conditions under which Storvik's lter works. Drawing on an analogy to the extended Kalman lter, we develop and analyze, both theoretically and experimentally, a Taylor approximation to the parameter posterior that allows Storvik's method to be applied to a broader class of models. Our experiments on both synthetic examples and real applications show improvement over existing methods.

关键词：滤波器；增量计算；参数空间

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We establish theoretical results concerning all local optima of various regularized M- estimators, where both loss and penalty functions are allowed to be nonconvex. Our results show that as long as the loss function satis es restricted strong convexity and the penalty function satis es suitable regularity conditions, any local optimum of the composite objective function lies within statistical precision of the true parameter vector. Our theory covers a broad class of nonconvex objective functions, including corrected versions of the Lasso for error-in-variables linear models; regression in generalized linear models using nonconvex regularizers such as SCAD and MCP; and graph and inverse covariance matrix estimation. On the optimization side, we show that a simple adaptation of composite gradient descent may be used to compute a global optimum up to the statistical precision stat in log(1=stat) iterations, which is the fastest possible rate of any rst-order method. We provide a variety of simulations to illustrate the sharpness of our theoretical predictions.

关键词：局部最优；理论模型；目标函数；线性模型

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Central to many statistical inference problems is the computation of some quantities defined over variables that can be fruitfully modeled in terms of graphs. Examples of such quantities include marginal distributions over graphical models and empirical average of observations over sensor networks. For practical purposes, distributed message-passing algorithms are well suited to deal with such problems. In particular, the computation is broken down into pieces and distributed among different nodes. Following some local computations, the intermediate results are shared among neighboring nodes via the so called messages. The process is repeated until the desired quantity is obtained. These distributed inference algorithms have two primary aspects: statistical properties, in which characterize how mathematically sound an algorithm is, and computational complexity that describes the efficiency of a particular algorithm. In this thesis, we propose low-complexity (efficient), message-passing algorithms as alternatives to some well known inference problems while providing rigorous mathematical analysis of their performances. These problems include the computation of the marginal distribution via belief propagation for discrete as well as continuous random variables, and the computation of the average of distributed observations in a noisy sensor network via gossip-type algorithms.

关键词：低复杂度；算法；分布式计算；消息传递

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This thesis introduces CANDID, a passive NetFlow-based network traffic analysis platform targeted at inferring relationships and dependencies among services running on hosts in enterprise networks. These networks present challenges of great scale, complexity, and nonstop dynamism, which hinder the ability for network administrators to maintain insight into the complex relationships that exist in these networks. Consequently, administrators do not always know how best to proceed if a network failure occurs. CANDID strives to empower administrators by illuminating these relationships, such that they will be prepared to remedy complex service failures.The solutions presented here take the rst steps towards understanding these complex in-network relationships, with a special focus on inferring one class of dependencies and detecting load balanced services. The focal point of this thesis is two radically di erent, yet complementary, strategies for inferring the presence of load balancing for pairs of systems.

关键词：网络故障；复杂网络关系；依赖性；重要性

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Modern websites perform many cross-site requests that can be detrimental to user privacy. Cross-site requests undermine privacy by allowing third-party websites——the websites that are the recipients of cross-site requests——to track a user's browsing behavior. As a result, some users turn to browser extensions that give them control over these requests. One such extension, RequestPolicy, implements a default-deny policy for cross-site requests and provides users an interface through which they manage a whitelist to allow blocked requests. This approach breaks many websites and requires frequent user interaction. We set out to gain insight into how RequestPolicy is used. We study RequestPolicy's usage through an opt-in telemetry study. Over a period of 24 weeks, we collected data from more than 2,500 RequestPolicy users about how they interact with RequestPolicy. We use this data, user feedback, and our own experiences to guide a redesign of RequestPolicy.

关键词：需求政策；交互；网站；用户隐私；跨站点请求

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Fully printable flexible transistors are key to high throughput production of flexible electronics at low cost. In this work, the advantages of an inverse gravure printing system and the solution-processing of 99% semiconductor enriched single-walled carbon nanotube (SWCNT) solutions are combined to fabricate fully printable SWCNT flexible top-gated thin-film transistors. The fully printed transistors exhibit high performance with mobility and on/off ratio up to 7.8 cm2/Vs and 104 while remaining stable when bent to 1 mm radius of curvature. With the transistors’ high performance, throughput, uniformity, flexibility and stability, we have demonstrated the potential for our printing process scheme to serve as the backplane for future scalable, low cost, high throughput, flexible electronics applications.

关键词：电子产业；碳纳米管；半导体；晶体管；电子应用程序

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