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用量子资源估计工具箱估算量子计算资源
Estimating the running time, number of qubits and other resources needed by realistic models of quantum computers is the rst necessary step to reducing these resource requirements. This report describes our Quantum Resource Estimator (QuRE) toolbox which we used to calculate resource estimates for a cross product of several quantum algorithms, quantum technologies, and error-correction techniques. The focus of this work is on the estimation methodology, overhead caused by error correction, and the software tools that we developed. Our toolbox simulates error correction with the Steane code [1, 2], Bacon-Shor code, Knill's post-selection scheme, and surface code, representing codes from both the concatenated and topological error-correcting code families.
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矩阵乘法中的防通信并行递归算法
Matrix multiplication is one of the most fundamental algorithmic problems in numerical linear algebra, distributed computing, scienti c computing, and high-performance computing. Parallelization of matrix multiplication has been extensively studied (e.g., [21, 12, 24, 2, 51, 39, 36, 23, 45, 61]). It has been addressed using many theoretical approaches, algorithmic tools, and software engineering methods in order to optimize performance and obtain faster and more ecient parallel algorithms and implementations. To design ecient parallel algorithms, it is necessary not only to load balance the computation, but also to minimize the time spent communicating between processors.
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在生产集群中的约束和软件电源管理技术
The proliferation of large clusters supporting online web workloads or large compute-intensive jobs has made cluster power management very important [1]. An analysis of utilization traces of production clusters reveal that a majority of them have a scope for (a) under-provisioning of electrical support infrastructure, leading to savings in capital expenditure, and (b) energy savings, leading to savings in operational expenditure; both with minimal impact on average job performance. Existing software techniques which tackle either of these problems have seen scant adoption because they do not address key problems and constraints relevant in production clusters.In this thesis, we first investigate possible reductions in cluster power infrastructure provisioning. It is possible that the lower provisioned power level is exceeded due to software behaviors on rare occasions and could cause the entire cluster infrastructure to breach the safety limits. A mechanism to cap servers to stay within the provisioned budget is needed, and processor frequency scaling based power capping methods are readily available for this purpose。
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用户引导逆3D建模
This thesis introduces and explores the idea of \user-guided inverse 3D modeling" — an interactive approach to shape construction and redesign that extracts well-structured, parameterized, procedural descriptions from unstructured, hierarchically at input data, such as point clouds, boundary representation meshes, or even multiple pictorial views of a given inspirational prototype. This approach combines traditional \forward" 3D modeling tools with a system of user-guided extraction modules and optimization routines. With a few cursor strokes users can express their preferences regarding the type of modeling primitives to be used in a particular area of the given prototype to be approximated, and they can also select the degree of parameterization associated with each modeling routine. The results are then pliable, structured descriptions that are well suited to implement the particular design modications intended by the user.
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机场安全管理系统试点研究的经验。机场合作研究项目(ACRP)第37项:机场综合实践。
This Synthesis studys objective is to provide airport operators with data and experience from SMS pilot study airports through survey results, lessons learned, and general findings and trends. The proposed audience is U.S. Part 139 certificated airport operators; however, while intended for Part 139 airports, the results gathered in this Synthesis of Practice may be helpful to all airports. The study approach focused on completing a literature review of current SMS industry documentation and conducting interviews with SMS pilot study airport representatives and consultants. Sources for the literature review included FAA, ICAO, the Government Accountability Office, various ACRP resources, Transport Canada, the Australian Governments Civil Aviation Safety Authority, and academic and industry references relating to SMS. The SMS pilot study interviews consisted of on-site or telephone discussions ranging from 30 to 90 min using a 36-question survey tool to address all aspects of the four SMS pilot studies, including program logistics, planning, staffing, and SMS integration and implementation. Of the 31 participating SMS pilot study airports, 26 airport operators respondedan 84response rate. Airports participants were represented from each of the four studies and from Class I, II, and IV airports (no Class III airports participated in the survey). Throughout this Synthesis study report, de-identified data and findings are presented by airport class to address differences in operational scale and staffing. Definitions of class size are presented in the Glossary of Terms and Acronyms.
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学习二次采样的数据:主动和随机策略
This dissertation addresses some of these issues:We begin with an active learning strategy for spectral clustering when the cost of assessing individual similarities is substantial or prohibitive.Next, we consider active learning in Bayesian models.Our third contribution looks at the e ects of randomized subsampling on Gaussian process models that make predictions about outliers and rare events. Finally, we turn to a theoretical evaluation of randomized subsampling for the purpose of inferring rankings of objects.
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扬声器的记录:当前的限制和新方向
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.
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GameTime:嵌入式软件的时序分析仪的内部实施和评估
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.
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使用FPGA来模拟大规模的新型数据中心网络架构
The tremendous success of Internet services has led to the rapid growth of Warehouse-Scale Computers (WSCs). The networking infrastructure has become one of the most vital components in a datacenter. With the rapid evolving set of workloads and software, evaluating network designs really requires simulating a computer system with three key features: scale, performance, and accuracy. To avoid the high capital cost of hardware prototyping, many designs have only been evaluated with a very small testbed built with off-the-shelf devices, often running unrealistic microbenchmarks or traces collected from an old cluster. Many evaluations assume the workload is static and that computations are only loosely coupled with the very adaptive networking stack. We argue the research community is facing a hardware-software co-evaluation crisis.In this dissertation, we propose a novel cost-efficient evaluation methodology, called Datacenter-in-a-Box at Low cost (DIABLO), which uses Field-Programmable Gate Arrays (FPGAs) and treats datacenters as whole computers with tightly integrated hardware and software. Instead of prototyping everything in FPGAs, we build realistic reconfigurable abstracted performance models at scales of O(10,000) servers. Our server model runs the full Linux operating system and open-source datacenter software stack, including production software such as memcached. It achieves two orders of magnitude simulation speedup over software-based simulators. This speedup enables us to run the full datacenter software stack for O(100) seconds of simulated time. We have built a DIABLO prototype of a 2,000-node simulated cluster with runtime-configurable 10 Gbps interconnect using 6 multi-FPGA BEE3 boards.
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数字调制发射机的效率增强的设计与分析
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.
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Skaion网络安全数据集的统计分析
This thesis considers the best use of network traffic data to increase cyber security. This operational problem is one of great concern to network administrators and users generally. Our specific task was performed for the Network Security Division of the Army Research Laboratory, who requested we analyze a dataset of cyber-attacks masked in a background of representative network traffic (the 'Skaion' dataset). We find that substantial preprocessing must done before statistical methods can be applied to raw network data, that no single predictor is sufficient, and that the most effective statistical analysis is logistic regression. Our approach is novel in that we consider not only single predictor events, but also combinations of reports from multiple tools. While we consider a number of different statistical techniques, we find that the most satisfactory model is based on logistic regression. Finally, we conclude that while the Skaion dataset is valuable in terms of its new approach to network traffic emulation, the 1999 KDD Cup and DARPA-MIT datasets-despite their many shortcomings-are more clearly organized and accessible to academic study. Cyber security is a globally important problem and datasets like Skaion's must maximize opportunities for cross-disciplinary academic endeavors.
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任意基质的半导体材料科学和器件物理
Since the beginnings of the semiconductor revolution, device engineering and material development have been deeply interconnected. Innovations in one invariably spurred development in the other. One of the most important current challenges are developing techniques which enable deposition of materials on arbitrary substrates and the design constraints of devices fabricated via these techniques. This thesis focuses on furthering the materials development-device design cycle for three techniques: (i) epitaxial lift-off, (ii) nanowire growth via the vapor-liquid-solid growth mode, and (iii) the thin-film vapor-liquid-solid growth technique. The physics of devices made via (i) and (ii) are discussed in chapters two and three, the material science of (iii) is discussed in chapter four, and a method to engineer the physical and electronic properties of individual nanowires made via (ii) is discussed in chapter two deals with the device physics and performance of ultra-thin compound semiconductor on insulator field effect transistors. Due to its excellent electron transport properties, InAs is used as the material of choice for the transistors, termed XOI FETs. These devices are fabricated utilizing an epitaxial layer transfer technique, enabling highly lattice mismatched single-crystalline layers of InAs to be deposited on Si wafers. Allowing devices which combine the excellent transport properties of compound-semiconductors and the established processing infrastructure for silicon. Chapter three discusses the design constraints and guidelines for nanopillar photovoltaics, specifically those fabricated utilizing the CdS/CdTe material system. Critically, the materials parameters that are favorable to non-planar cells are discussed, and the performance expectations for CdS/CdTe nanopillar photovoltaics are discussed.