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43341.快车道:为提高数据中心性能的一种敏捷拥塞信号机制
[信息传输、软件和信息技术服务业] [2013-11-07]
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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43342.基于物理渲染的快速筛选
[信息传输、软件和信息技术服务业] [2013-11-07]
Ray tracing allows for physically-accurate renderings of various phenomena, producing a highquality image. Because of its computational complexity, ray tracing is typically reserved for offline rendering, where each image is allowed virtually unlimited time to render. Much work has been done to accelerate ray tracing to enter the interactive domain, requiring each image to be produced in less than a few seconds. Current ray tracers can interactively produce images with only a limited subset of their possible offline effects. My work with Professor Ravi Ramamoorthi and Soham Mehta focuses on physical phenomena that are too computationally expensive to render interactively. We focus on two effects: soft shadows cast by area lights and di?use indirect lighting, but the principles behind our work can be applied to various other phenomena.
关键词:物理渲染;筛选;射线追踪
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43343.用户引导逆3D建模
[信息传输、软件和信息技术服务业] [2013-11-07]
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.
关键词:用户引导逆3D建模;用户交互;3D建模工具
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43344.自动手势识别与理疗跟踪系统
[信息传输、软件和信息技术服务业] [2013-11-07]
Physical Therapy is a branch of rehabilitative health that uses specially designed exercises and equipment to help patients regain or improve their physical abilities. Researchers have explored the use of software based rehabilitation tools based on video game consoles like Nintendo Wii Fit and Microsoft Kinect to provide remote rehabilitation facilities to patients. We propose a Kinect based Physical Therapy Application that guides patients to perform exercises and assists therapists to monitor as well as teach the specially designed exercises to patients. The application includes an Automated Exercise Generator for therapists to de ne exercises, an Automated Gesture Recognition and Tracking System to track and guide the patients while they perform the exercises and a Visual Feedback System for patients to correct the position and movement of their Joints. In this paper, we investigate how to enable continuous tracking of patients for pre-authored physiotherapy exercises. We introduce a state-machine-based approach that tracks a patient's progress and provides continuous feedback indicating whether the patient is doing an exercise correctly or not.
关键词:物理治疗;康复工具;自动手势识别;跟踪系统
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43345.底纹的形状,照明和反射
[信息传输、软件和信息技术服务业] [2013-11-07]
A fundamental problem in computer vision is that of inferring the intrinsic, 3D structure of the world from flat, 2D images of that world. Traditional methods for recovering scene properties such as shape, reflectance, or illumination rely on multiple observations of the same scene to overconstrain the problem. Recovering these same properties from a single image 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 more likely 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. Our technique 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:场景属性;经典计算机视觉问题;解决方案
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43346.矩阵乘法中的防通信并行递归算法
[信息传输、软件和信息技术服务业] [2013-11-07]
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.
关键词:通信模式;矩阵乘法;递推算法;数字线性代数;分布式计算;
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43347.在生产集群中的约束和软件电源管理技术
[信息传输、软件和信息技术服务业] [2013-11-07]
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。
关键词:生产集群;电源管理;服务器
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43348.机场安全管理系统试点研究的经验
[信息传输、软件和信息技术服务业] [2013-11-05]
In 2001, the International Civil Aviation Organization (ICAO), an agency of the United Nations with international aviation oversight, adopted a new standard in Annexes 6 (Operation of Aircraft), 11 (Air Traffic Services), and 14 (Aerodromes), requiring that all 192 contracting states establish safety management system (SMS) requirements. According to ICAO, "safety is increasingly viewed as the outcome of the management of certain organizational processes, which have the objective of keeping the safety risks of the consequences of hazards in operational contexts under organizational control.
关键词:电子信息;安全管理系统;经验
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43349.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。
[信息传输、软件和信息技术服务业] [2013-11-05]
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.
关键词:电子信息;安全管理系统(SMS);经验
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43350.安全管理系统试点研究项目管理
[信息传输、软件和信息技术服务业] [2013-11-05]
Once fully implemented, SMS is an operational system. However, there is a significant amount of planning and activity required to bring SMS from inception to normal operations. Program management is the set of structures, tools, activities, and personnel that is employed by airports to realize a fully functional and operational SMS.
关键词:电子信息;安全管理系统(SMS);操作系统;项目管理