Mixed-criticality systems, in which multiple tasks of varying criticality are executed on a single hardware platform, are an emerging research area in real-time embedded systems. High-criticality tasks require spatial and temporal isolation guarantees, whereas low-criticality tasks should efficiently utilize hardware resources. Hardware-based isolation is desirable, but commonly underutilizes hardware resources, which can consist of multiple single-core, multicore, or multithreaded processors. We present FlexPRET, a processor designed specifically for mixed-criticality systems by allowing each task to make a trade-off between hardware-based isolation and efficient processor utilization. Flex-PRET uses fine-grained multithreading with flexible scheduling and timing instructions to provide this functionality.

关键词：计算机体系结构；效率；嵌入式系统；现场可编程门阵列

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In this paper, we present an approach to large-scale data analysis, Divide and Recombine (D&R), and describe a hardware and software implementation that supports this approach. We then illustrate the use of D&R on large-scale power systems sensor data to perform initial exploration discover multiple data integrity issues, build and validate algorithms to filter bad data, and construct statistical event detection algorithms. This paper also reports on experiences using a non-traditional Hadoop distributed computing setup on top of a HPC computing cluster.

关键词：算法；计算机程序；分布式数据处理；划分和重组

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This document provides an overview for the optimisation of the ARAMIS v6.3.0 digital image correlation system (GOM mbH, Germany) for use in a large-scale, high strain-rate synergistic blast and fragmentation event. The ARAMIS system uses 3D digital photogrammetry to track surface deformation of an object during an event and produces the resultant strain data. This document highlights some key considerations for use of high-speed photogrammerty for synergistic events, not fully covered by the hardware and software manuals or literature.

关键词：高炉；计算机程序；数字图像相关；数字系统

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The ability to accurately predict the performance of software components executing within a Cloud environment is an area of intense interest to many researchers. The availability of an accurate prediction of the time taken for a piece of code to execute would be beneficial for both planning and cost optimisation purposes. To that end, this paper proposes a performance data capture and modelling architecture that can be used to generate models of code execution time that are dynamically updated as additional performance data is collected. To demonstrate the utility of this approach, the workflow engine within the e-Science Central Cloud platform has been instrumented to capture execution data with a view to generating predictive models of workflow performance. Models have been generated for both simple and more complex workflow components operating on local hardware and within a virtualised Cloud environment and the ability to generate accurate performance predictions given a number of caveats is demonstrated.

关键词：云计算；预测建模；计算机软件

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When the quality of service (QoS) of an unmanned air vehicle's (UAV) communications link is poor, and the UAV is tracking a moving target, a trade- off exists between the fidelity and timeliness of information provided from the vehicle to an operator. The authors' 2011 ICCRTS paper showed that an optimal representation scheme for transmitting information from UAV to operator can be found by using information theory. This paper extends that work by introducing an adaptive, autonomous UAV command and control system that autonomously changes the fidelity of information communicated to an operator in response to variances in communications QoS. Results and analysis of hardware-in-the-loop experiments using a UAV that is tracking a moving car are presented. The paper also examines the impact of information decay and network performance on both human tele-operation and on-board autonomous control, comparing the relative performance of tele-operation and autonomy as a function of entropic drag, which is a measurement, in information theory 'bits,' of the rate at which information is lost due to unpredictable changes in the environment. In the experiments described in this paper, entropic drag is produced by the movement of the vehicle being tracked.

关键词：蜂窝通信；指挥和控制系统；无人机;信息交流

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All spacecraft represent a considerable investment of both time and money. To ensure mission success, testing and validation of all vital systems is crucial to the design process. The attitude control subsystem (ACS) is typically tested thoroughly, to include both hardware and control algorithms. Computer simulations offer a simple and relatively cheap method of predicting the performance of the ACS; however, computer simulations cannot provide the assurances necessary to qualify an ACS hardware configuration or control algorithm spaceworthy. For this reason, physical spacecraft simulators must be used to validate ACS dynamics. Previous research showed there is room for significant improvement to the design methodology of lab-rated control moment gyroscopes (CMGs), which can be used as attitude control devices. An improved design methodology was created to streamline the design process and develop best practices. To evaluate the design methodology, a CMG ACS was designed for the Attitude Control Subsystem Proving Ground (ACSPG), and a prototype was tested.

关键词：人工卫星；姿态控制系统；轴承；CMG

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This is the final report of project FANTOM, which was a part of the DESA program supported by the DSO office, DARPA, during the period between May 2005 and Aug. 2009, with a no-cost extension to Feb. 2010.

关键词：算法；计算机体系结构；嵌入式系统；芯片（电子）

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Under this task, we have augmented the hardware of the Long Wavelength Array (LWA) to provide a significant riometric capability, in order to search for anomalous absorption events that are associated with radiation belt precipitation events.

关键词：辐射带；数组；电离层；无线电干涉

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The U.S. Geological Survey Cascade Routing Tool (CRT) is a computer application for watershed models that include the coupled Groundwater and Surface-water FLOW model, GSFLOW, and the Precipitation-Runoff Modeling System (PRMS). CRT generates output to define cascading surface and shallow subsurface flow paths for grid-based model domains. CRT requires a land-surface elevation for each hydrologic response unit (HRU) of the model grid; these elevations can be derived from a Digital Elevation Model raster data set of the area containing the model domain. Additionally, a list is required of the HRUs containing streams, swales, lakes, and other cascade termination features along with indices that uniquely define these features. Cascade flow paths are determined from the altitudes of each HRU. Cascade paths can cross any of the four faces of an HRU to a stream or to a lake within or adjacent to an HRU. Cascades can terminate at a stream, lake, or HRU that has been designated as a watershed outflow location.

关键词：网格；流域；地下水；计算机应用；磷；环境管理

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Software-defined radios (SDRs) provide researchers with powerful and flexible wireless communications experimentation platforms. This report describes the development and usage of an U.S. Army Research Laboratory (ARL)- developed powerful software library that allows the user to interface with the Universal Software Radio Peripheral (USRP) family of radio hardware using MATLAB. This library enables fast prototyping of algorithms on SDRs.

关键词：软件工具；算法；无线通信；USRP

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