The integration of Unmanned Aircraft Systems (UAS) in the National Airspace represents new operational concepts required in civil aviation. These new concepts are evolving as the nation moves toward the Next Generation Air Transportation System (NextGen) under the leadership of the Joint Planning and Development Office (JPDO), and through ongoing work by the Federal Aviation Administration (FAA). The desire and ability to fly UAS in the National Air Space (NAS) in the near term has increased dramatically, and this multi-agency effort to develop and implement a national plan to successfully address the challenges of UAS access to the NAS in a safe and timely manner is well underway. As part of the effort to integrate UAS in the National Airspace, NASA Glenn Research Center is currently involved with providing research into Communications systems and Communication system operations in order to assist with developing requirements for this implementation. In order to provide data and information regarding communication systems performance that will be necessary, NASA GRC is tasked with developing and executing plans for simulations of candidate future UAS command and control communications, in line with architectures and communications technologies being developed and/or proposed by NASA and relevant aviation organizations (in particular, RTCA SC-203). The simulations and related analyses will provide insight into the ability of proposed communications technologies and system architectures to enable safe operation of UAS, meeting UAS in the NAS project goals (including performance requirements, scalability, and interoperability), and ultimately leading to a determination of the ability of NextGen communication systems to accommodate UAS. This presentation, compiled by the NASA GRC team, will provide a view of the overall planned simulation effort and objectives, a description of the simulation concept and status of the design and development that has occurred to date.

关键词：飞机通讯；通信网络；无线电通信；无人驾驶飞机系统

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The building blocks of emerging Petascale massively parallel processing (MPP) systems are multi-core processors with four or more cores as a single processing element and a customized network interface. The resulting memory and communication hierarchy of these platforms are now exposed to application developers and end users by creating a hierarchical or multi-core aware message-passing (MPI) programming interface and by providing a handful of runtime, tunable parameters that allows mapping and control of MPI tasks and message handling. We characterize performance of MPI communication patterns and present strategies for optimizing applications performance on Cray XT series systems that are composed of contemporary AMD processors and a proprietary network infrastructure. We highlight dependencies in its memory and network subsystems, which could influence production-level applications performance. We demonstrate that MPI micro-benchmarks could mislead an application developer or end user since these benchmarks often do not expose the interplay between memory allocation and usage in the user space, which depends on the number of tasks or cores and workload characteristics. Our studies show performance improvements compared to the default options for our target scientific benchmarks and production-level applications.

关键词：通信;并行编程;基准;通讯执行情况;内存

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The classical mean shift (MS) algorithm is the best color-based method for object tracking.However,in the real environment it presents some limitations,especially under the presence of noise,objects with partial and full occlusions in complex environments.In order to deal with these problems,this paper proposes a reliable object tracking algorithm using corrected background-weighted histogram (CBWH) and the Kalman filter (KF) based on the MS method.The experimental results show that the proposed method is superior to the traditional MS tracking in the following aspects:1) it provides consistent object tracking throughout the video; 2) it is not influenced by the objects with partial and full occlusions; 3) it is less prone to the background clutter.

关键词：目标跟踪;均值漂移;背景资料;卡尔曼滤波器;通信

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Communication, i.e., moving data, between levels of a memory hierarchy or between parallel processors on a network, can greatly dominate the cost of computation, so algorithms that minimize communication can run much faster (and use less energy) than algorithms that do not. Motivated by this, attainable communication lower bounds were established for a variety of algorithms including matrix computations. The lower bound approach used initially for Theta(N3) matrix multiplication, and later for many other linear algebra algorithms, depended on a geometric result by Loomis and Whitney: this result bounded the volume of a 3D set (representing multiply-adds done in the inner loop of the algorithm) using the product of the areas of certain 2D projections of this set (representing the matrix entries available locally, i.e., without communication). Using a recent generalization of Loomis' and Whitney's result, we generalize this lower bound approach to a much larger class of algorithms, that may have arbitrary numbers of loops and arrays with arbitrary dimensions as long as the index expressions are a ne combinations of loop variables. In other words, the algorithm can do arbitrary operations on any number of variables like A(i(sub 1), i(sub 2), i(sub 2) - 2i(sub 1), 3 - 4i(sub 3) + 7i(sub 4), ...). Moreover, the result applies to recursive programs, irregular iteration spaces, sparse matrices, and other data structures as long as the computation can be logically mapped to loops and indexed data structure accesses. We also discuss when optimal algorithms exist that attain the lower bounds; this leads to new asymptotically faster algorithms for several problems.

关键词：微分方程；线性代数；通信；数据结构；数据传输

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Programming with communication libraries such as the Message Passing Interface (MPI) obscures the high-level intent of the communication in an application and makes static communication analysis difficult to do. Compilers are unaware of communication libraries’ specifics, leading to the exclusion of communication patterns from any automated analysis and optimizations. To overcome this, communication patterns can be expressed at higher-levels of abstraction and incrementally added to existing MPI applications. In this paper, we propose the use of directives to clearly express the communication intent of an application in a way that is not specific to a given communication library. Our communication directives allow programmers to express communication among processes in a portable way, giving hints to the compiler on regions of computations that can be overlapped with communication and relaxing communication constraints on the ordering, completion and synchronization of the communication imposed by specific libraries such as MPI. The directives can then be translated by the compiler into message passing calls that efficiently implement the intended pattern and be targeted to multiple communication libraries. Thus far, we have used the directives to express point-to-point communication patterns in C, C++ and Fortran applications, and have translated them to MPI and SHMEM.

关键词：分布式数据处理；计算机通讯；编程语言；通信

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Warfighting based on Commander s Intent and Mission Tactics will remain the foundation of command and control, but the information structure that supports Marine Corps tactical units will continuously undergo changes based on developments in information technology. Mobile Ad Hoc Networking is one of the information technology developments that the Marine Corps is currently studying. Mobile Ad Hoc Network s (MANETs) are infrastructureless, highly mobile communications and their multi-hop routing capabilities have the potential to reliably and robustly extend existing networks to the tactical edge. There are many challenges to MANET implementation however, including management of the dynamic physical topology, and the efficient use of limited spectral and energy resources. One platform being tested by the Marine Corps utilizes a time-division multiple access (TDMA) scheme combined with Barrage Relaying to ensure robust communications. Other schemes for MANETs employ intelligent-routing protocols. This thesis examines those protocols and identifies the parameters needed to implement a tactical MANET routing scheme. The findings of this research advance understanding of MANETs and the elements necessary to enable their use in support of tactical communications; bringing the Marine Corps closer to its goal of lightweight and efficient tactical communications.

关键词：网络;路由;战术通信;通信和无线电系统;基础（结构）

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ragonfly is a password authenticated key exchange protocol that has been submitted to the Internet Engineering Task Force as a candidate standard for general internet use. We analyzed the security of this protocol and devised an attack that is capable of extracting both the session key and password from an honest party. This attack was then implemented and experiments were performed to determine the time-scale required to successfully complete the attack.

关键词：数据处理;攻击;认证;通信协议

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The broad research objective of the overall project was the development of multi-scale optimization approaches to aid in the design of energy storage systems. More specically, we focused on the development of optimization methods that operate on different physical length-scales for optimizing the internal structure of nanoporous materials. Potential applications include electrical supercapacitors and hydrogen storage systems. The optimization algorithms we have developed can be applied to more general hierarchical design problems arising from the design of complex systems.

关键词：储氢；纳米材料；分层问题；优化算法；技术报告

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Devices that provide hearing protection, situational awareness and radio communications are often referred to as Communications and Hearing Protection Systems (C&HPS). Soldiers use these systems to maintain auditory awareness within their environment, communicate with their team members and protect their hearing. Each of the three features of select C&HPS (hearing protection, speech communication and situational awareness) were independently evaluated by the U.S. Army Research Laboratory (ARL). This report is the third in a series of three and focuses on the auditory localization performance obtained from two commercially available C&HPS: Nacre QuietPro and Silynx QuietOps. These two systems were selected from three C&HPS evaluated for attenuation characteristics in the first report and speech intelligibility in the second report; the third system provided insufficient attenuation to be included. Results of the auditory localization testing indicated that both C&HPS negatively affected auditory localization accuracy performed in background noise, but the observed decrement was not significantly different between the two systems. Evidence from objective measures of the systems such as directivity, calculation of interaural level differences (ILDs), and the measurement of input/output functions indicate that changes in binaural intensity difference cues were the primary factor driving the reduction in performance.

关键词：通信和广播系统;背景噪音;语音通信;输入输出处理

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In this paper we introduce CARRQR, a communication avoiding rank revealing QR factorization with tournament pivoting. We show that CARRQR reveals the numerical rank of a matrix in an analogous way to QR factorization with column pivoting (QRCP). Although the upper bound of a quantity involved in the characterization of a rank revealing factorization is worse for CARRQR than for QRCP, our numerical experiments on a set of challenging matrices show that this upper bound is very pessimistic, and CARRQR is an effective tool in revealing the rank in practical problems. Our main motivation for introducing CARRQR is that it minimizes data transfer, modulo poly- logarithmic factors, on both sequential and parallel machines, while previous factorizations as QRCP are communication sub-optimal and require asymptotically more communication than CARRQR. Hence CARRQR is expected to have a better performance on current and future computers, where communication is a major bottleneck that highly impacts the performance of an algorithm.

关键词：通信;数据传输;QR分解;通信优化算法

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