In 1965 Klyuev and Kokovkin-Shcherbak proved that that n^3/3n3+O(n^2)multiplications are necessary to solve an n-by-n system of linear equations. In 1969 Strassen proved O(n^(log2 7)) multiplications are sucient. They could both be right because they considered di erent models of permitted algorithms. Here we propose yet another algorithmic model, closer in spirit to Klyuev and Kokovkin-Shcherbak, but suciently more general to be able to provide lower bounds on the number of arithmetic operations required to perform dense, sparse or \structured" one-sided matrix factorizations: The simplest (and overly restrictive) version of our assumption is that each scalar result is computed using only the data on which it depends mathematically. We compare these lower bounds with a variety of algorithms and matrix sparsity patterns and algebraic structures (such as Vandermonde). Depending on the sparsity patterns and structures, conventional algorithms may or may not attain the lower bounds. In some cases when they do not, we present new algorithms that do. These bounds are based on a simple, general lower bound for the arithmetic complexity of computing rational functions.

关键词：算法模型；代数结构；算数运算；

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The last decade has witnessed a tremendous growth in wireless communications. Consumer demands for battery-operated mobile devices with versatile, high data-rate communication capabilities that are of low cost, small form-factor and long operating cycle have motivated the research on fully-integrated, back-o -effcient and coexistence-friendly wireless transceivers in CMOS VLSI technology. However, the full integration of an ecient CMOS power ampli er (PA) into such a transceiver is still among the most difficult challenges towards a true System-On-Chip (SOC) solution. This thesis investigates the PA eciency enhancement techniques for a complete power transmitter system that is fully-integrated and coexistable.

关键词：数字调制发射机；无线通信；增强效率

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A Massive Open Online Course (MOOC) is a large-scale web-based course that is offered to a very large number of participants. In the last few years, MOOCs have seen an increase in popularity due to the emergence of several well-designed online-education websites, such as edX and Coursera, and rising interest from top universities, such as MIT, Stanford and UC Berkeley, to open a variety of their courses to the wider public. The appeal for end consumers lies in the accessibility of high-quality education from any location regardless of personal background. MOOCs typically contain short lecture videos (10-15 minutes), as well as quizzes and homework assignments to assess students’ understanding of subject matter.

关键词：隐马尔科夫模型；预测；学生保留；

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Gesture recognition allows users to interact with their electronic devices in a manner that mimics their interaction with the physical world, thus making devices easier to use for all users. Interacting with the software, using gesture and body motion is definitely a cool ideal. However, designing effective interactions is a challenge on a gesture-controlled application.We partnered with the Microsoft Windows Phone Team to develop a Kinect physiotherapy application. This application enables the patients to perform recovery exercises remotely at home. It checks the patient’s body movements against doctors’ instructions and provides real-time instructions to the patients.

关键词：用户界面；手势识别；技术；网络交互软件

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Because of the emerging trend of mobile, developing applications on smartphone platform gathers more and more people’s interests. Our capstone project is to build a mobile application on the Android platform that generates a house floor plan overlaid with Wi-Fi strength map. Right now in the market, there are plenty of mobile apps about measuring the floor plan or the WiFi signal strength, but there has not been an app that combines those two features. Since Wi-Fi is becoming the de facto standard for in-home wireless connectivity between devices inside the home, our industry partner, Qualcomm, thought this could be a great feature to be added to thefloor plan app. We divided the whole product into two parts. One is the house floor plan, the other is the WiFi signal strength map. We finished those two separately then assembled them together. The whole developing process includes the selection of the main algorithms for the floor plan measurement and the WiFi signal strength, graphical user interface design as well as some marketing research. Finally we achieved that the error of the measurement result given by our application is within 10%. After the measurement process, the user can get the desired floorplan with the WiFi signal strength map

关键词：智能应用程序；WIFI覆盖平面图；无线连接；

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In this project we examine the possibilities of bringing the gesture recognition to Windows Phone and Surface tablet devices by integrating Kinect to the aforementioned devices. We will demonstrate this by designing a physiotherapy application.In physiotherapy exercises, it is very important and critical to the patient to do the exercises as accurately as possible. So our physiotherapy application should have the ability to give feedback to the users in order for them to do the exercises correctly. For this purpose, we decided to render 3D arrows that show users how to adjust incorrectly positioned limbs.

关键词：手势识别；理疗应用程序；3D反馈

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In the last 50 years, information technology has automated many jobs like word processing, mathematical calculation and data retrieval. However, as driving a car is much more difficult than such simple jobs, it has always been a dream to do so autonomously with a computer. With the development of related technologies, people have begun significant work on making this dream a reality.For automakers, it is more profitable to invest in a mature market – semi-automatic vehicles. However, this project aims to develop a fully automated driving system that is profitable in the market.

关键词：信息技术自动化；GPS驱动器；自动驾驶系统

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Timing analysis is central to the design and implementation of cyber-physical systems. This thesis presents GameTime, a timing analysis toolkit that is based on a combination of game-theoretic online learning and systematic testing using satis ability modulo theories (SMT) solvers. GameTime can be used to tackle a range of problems related to program timing, including estimating the worst-case execution time, predicting the distribution of execution times, and detecting timing-related anomalies.This thesis describes the details of the implementation of GameTime. The notion of basis paths is used to handle the exponentially many paths in a program. The issues that arise during the translation of statements in C programs to the equivalent clauses in SMT queries are presented, and the techniques used by GameTime to address these issues are elaborated through examples. Finally, experimental results demonstrate the speed of GameTime analysis and the accuracy of the predictions made by GameTime, with a relative error margin of less than 5% on most of the benchmarks measured.

关键词：时序分析；基准路径；内部实施和评估

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The drive towards richer, more interactive content places increasingly stringent latency requirements on datacenters. A critical component of meeting these is ensuring that the network responds agilely to congestion, bounding network latency and improving high-percentile flow completion times. We propose a new approach to rapidly detecting and responding to congestion. We introduce FastLane, a congestion signaling mechanism that allows senders to respond more quickly. By delivering signals to senders with high probability and low latency, FastLane allows them to retransmit packets sooner, avoiding resource-wasting timeouts. It also enables senders to make more informed decisions by differentiating between out-of-order delivery and packet loss. We demonstrate through simulation and implementation that FastLane reduces high-percentile flow completion times by over 80% by effectively managing congestion hot-spots. These benefits come at minimal cost—FastLane consumes no more than 2% of bandwidth and 5% of buffers.

关键词：拥塞信号机制；拥塞管理；响应敏捷；

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Speaker diarization is the problem of determining “who spoke when” in an audio recording when the number and identities of the speakers are unknown. Motivated by applications in automatic speech recognition and audio indexing, speaker diarization has been studied extensively over the past decade, and there are currently a wide variety of approaches – including both top-down and bottom-up unsupervised clustering methods. The contributions of this thesis are to provide a unified analysis of the current state-of-the-art, to understand where and why mistakes occur, and to identify directions for improvements.In the first part of the thesis, we analyze the behavior of six state-of-the-art diarization systems, all evaluated on the National Institute of Standards and Technology (NIST) Rich Transcription 2009 evaluation dataset. While performance is typically assessed in terms of a single number – the diarization error rate (DER) – we further characterize the errors based on speech segment durations and their proximity to speaker change points.

关键词：语音识别和音频索引；扬声器系统；改善

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