In this paper, we analyze seven MapReduce workload traces from production clusters at Facebook and at Cloudera customers in e-commerce, telecommunications,edia, and retail. Cumulatively, these traces comprise over a year’s worth of data logged from over 5000 machines, and contain over two million jobs that perform 1.6 exabytes of I/O. Key observations include input data forms up to 77% of all bytes, 90% of jobs access KB to GB sized files that make up less than 16% of stored bytes, up to 60% of jobs re-access data that has been touched within the past 6 hours, peak-to-median job submission rates are 9:1 or greater, an average of 68% of all compute time is spent in map, task-seconds-per-byte is a key metric for balancing compute and data bandwidth, task durations range from seconds to hours, and five out of seven workloads contain map-only jobs. We have also deployed a public workload repository with workload replay tools so that the researchers can systematically assess design priorities and compare performance across diverse MapReduce workloads.

关键词：集群生产工作量；电子商务；公共负载资料库；工作负载

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Big data is an inherent feature of the cloud and provides unprecedented opportunities to useboth traditional, structured database information and business analytics with social networking,sensor network data, and far less structured multimedia. Big data applications require a data-centric compute architecture, and many solutions include cloud-based APIs to interface withadvanced columnar searches, machine learning algorithms, and advanced analytics such ascomputer vision, video analytics, and visualization tools. This article examines the use of the Rlanguage and similar tools for big data analysis and methods to scale big data services in thecloud. It provides an in-depth look at digital photo management as a simple big data servicethat employs key elements of search, analytics, and machine learning applied to unstructureddata.

关键词：定义；系统设计；系统运用；云数据

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We consider optimal representations for representing prototypical categories in the latent deformable part model framework, with a specific emphasis on category-level retrieval tasks defined “on the fly” for a large corpus. In this
setting, it is impractical to perform an exhaustive search with a full model; we investigate methods which approximately reconstruct the score function of a novel category from a set of precomputed responses. We propose a novel
sparse reconstruction method where part classifiers are decomposed via a shared dictionary of part filters; in turn, our method can efficiently reconstruct approximate part responses on large image corpora using a sparse matrixvector product based on pre-computed filter responses instead of exhaustive convolutions. We compare our method to baseline schemes using SVD-based or nearest-category approximation and show our method is more effective at detecting novel categories. We additionally demonstrate results towards an end-to-end system for activity detection which trains a protoype category concept model from one dataset (PASCAL), learns post-hoc categories on the fly based on training data from a second dataset where labeled data are available (ImageNet), and sucessfully detects instances
in test data from a third dataset (TRECVID MED) via reconstruction with the precomputed prototype models.

关键词：模型框架原型;类级别检索;穷举搜索;稀疏重建方法;

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Discover the reasons for introducing lease policies into large cloud environments. This articleelaborates on one specific pattern deployment lease policy tailored for IBM PureApplication System, IBM SmartCloud Provisioning, and IBM Workload Deployer. The design andimplementation described here is a proven example of building lease policies for a cloudenvironment.

关键词：模式部署租用策略；实施；希望

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A broadband power amplifier design approach was used to design several monolithic microwave integrated circuits (MMICs) using a 0.13- m gallium arsenide (GaAs) pseudomorphic high electron mobility transistor (PHEMT) process from TriQuint Semiconductor. The design and fabrication of these circuits were performed as part of the fall 2011 Johns Hopkins University (JHU) MMIC Design Course, taught by the author. The design approach is taught by Dale Dawson in the JHU Power MMIC Design Course. This approach is useful for designing relatively broadband amplifiers that are limited only be the active transistor's 'Q'.

关键词：电子信息；电子；集成电路；放大器

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In this chapter, RF modulation schemes effects on RF power amplifier nonlinearities are presented. A review of various power amplifier RF linearization techniques are discussed. 2.2 RF Modulation Scheme in Bandpass Radio Communication Channel In radio communications, modulation can be described as the process of conveying a message signal by superimposing an information bearing signal onto a carrier signal by varying the signal characteristic [31-33]. Modulation is the process of changing a higher frequency signal in proportion to a lower frequency one or vise versa.

关键词：电子信息；电子；功率放大器；线性化技术

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A brief review of the properties of the material and device structures for photodiodes, and an update on the performance of high power waveguide photodiodes, including simulation results of directional coupled waveguide photodiodes, for analog link applications will be provided. The underlying physical mechanisms responsible for nonlinearities in high power photodiodes will be discussed in the presentation.

关键词：电子信息；电子；高功率；光电二极管

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Forced flow of fluids undergoing phase change in traditional single- phase cold plates is an effective way to manage waste heat removal of vehicle power electronics. Such cold plates come in a variety of standard styles, ranging from circular-tubed cold plates and flat-tube cold plates, to more exotic designs such as louvered and offset fin cold plates. The mechanisms of heat transfer in a two-phase system are different than single-phase, and as such, improvement can be made by custom designing cold plates for two-phase operation. Past research has focused on surface modifications that enhance nucleate boiling, convective vaporization, or both during two-phase operation. The method that has gained the most attention is the use of inner grooved tubes for performance improvement in refrigeration applications. Despite the popularity of inner grooved tubes, the flow mechanisms that deliver performance enhancement are not fully understood. The absence of phenomenological insights and physical models makes it difficult to transition inner grooved tube technology from conventional refrigeration equipment to cold plates. Therefore, understanding the physical mechanisms underpinning two-phase performance enhancement in inner grooved tubes is at the heart of this report.

关键词：电子信息；电子；冷却板；电力产品

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This work was done in the following directions: 1. Excitation of parasitic waves near cutoff in forward-wave amplifiers; 2. Periodic dielectric slow-wave structures; 3. Role of metallic dust on operation of high-power sources of electromagnetic radiation. The problem of excitation of dangerous parasitic modes in high-power amplifiers operating in high-order waves was studied, first, assuming strong focusing fields, in which electrons perform 1D motion. Then, the approach was generalized to the case of weak guiding fields, in which electrons exhibit 3D motion. The effect of guiding fields and other parameters on the conditions of parasitic excitation was analyzed and illustrated by design examples. Periodic dielectric slow-wave structures may exhibit an interesting class of new metamaterials attractive for high-power, millimeter-wave amplifiers. The theory of such structures has been developed and illustrated by some examples. Heating and melting of small micro-particles (metallic dust) in strong microwave fields may initiate the breakdown events in high-power microwave (HPM) sources. These processes have been studied in HPM sources operating in rep-rate regimes.

关键词：电子信息；电子；功率放大器；短波

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This program focused on new materials and fiber designs towards the realization of 100+ kW class eye-safe fiber lasers based on the following guiding principles: large mode area, single mode, purity of polarization state, minimization of nonlinear effects, compatibility with all-fiber pumps, and high temperature buffer coatings. Over the duration of this program the most significant findings are discussed below in the following sections: (1) Gain guided index anti guided fiber lasers; (2) High temperature fiber coatings; (3) Tm doped fiber lasers 4. Tm doped Photonic Crystal Fiber (PCF) lasers.

关键词：电子信息；电子；高功率；激光器

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