Oxygen reduction reaction (ORR) is important in fuel cells. Although platinum nanoparticles can catalyse the ORR in an efficient way, the high cost of the platinum catalysts, together with its limited reserves in nature, has been shown to be the major 'showstopper' to mass market fuel cells for commercial applications. Following our earlier work on metal-free, nitrogen- doped carbon nanotubes (Gong, K.; Du, F.; Xia, Z.; Durstock, M.; Dai, L. Science 2009, 323, 760) and nitrogen-doped graphene sheets (Qu, L.; Liu, Y.; Baek, J.-B.; Dai, L. ACS Nano 2010, 4, 1321) as highly efficient ORR, we have developed in this project new metal-free and oxygen-free graphene materials by either edge-functionalization or ball milling as efficient electrocatalysts for ORR in fuel cells and other applications, including dye-sensitized solar cells (DSSCs).

关键词：催化剂；燃料电池；石墨烯；纳米技术

查看摘要 索取原文[11页]

Turbine engines are highly complex mechanical systems that are becoming increasingly dependent on control technologies to achieve system performance and safety metrics. However, the contribution of controls to these measurable system objectives is difficult to quantify due to a lack of tools capable of informing the decision makers. This shortcoming hinders technology insertion in the engine design process. NASA Glenn Research Center is developing a Hardware-inthe- Loop (HIL) platform and analysis tool set that will serve as a focal point for new control technologies, especially those related to the hardware development and integration of distributed engine control. The HIL platform is intended to enable rapid and detailed evaluation of new engine control applications, from conceptual design through hardware development, in order to quantify their impact on engine systems. This paper discusses the complex interactions of the control system, within the context of the larger engine system, and how new control technologies are changing that paradigm. The conceptual design of the new HIL platform is then described as a primary tool to address those interactions and how it will help feed the insertion of new technologies into future engine systems.

关键词：主动控制；复杂的系统；发动机控制；发动机设计

查看摘要 索取原文[18页]

We demonstrate, for the first time, high-speed circuits that generate partitions on a set S of n objects. We offer two versions. In the first, partitions are produced in lexicographical order in response to successive clock pulses. In the second, an index input determines the set partition produced. Such circuits are needed in the hardware implementation of the optimum distribution of tasks to processors. Our circuits are combinational. For large n, they can have large delay. However, one can easily pipeline them to produce one set partition per clock period. We show (1) analytical and (2) experimental time/complexity results that quantify the efficiency of our designs. Our results show that a hardware partition generator running on a 100 MHz FPGA produces partitions at a rate that is approximately 10 times the rate of a software implementation on a processor running at 2.26 GHz.

关键词：计算机程序；电路；时钟；转换器

查看摘要 索取原文[13页]

Malware, also known as malicious code, refers to a program that is covertly inserted into another program with the intent to destroy data, run destructive or intrusive programs, or otherwise compromise the confidentiality, integrity, or availability of the victims data, applications, or operating system. Malware is the most common external threat to most hosts, causing widespread damage and disruption and necessitating extensive recovery efforts within most organizations. This publication provides recommendations for improving an organizations malware incident prevention measures. It also gives extensive recommendations for enhancing an organizations existing incident response capability so that it is better prepared to handle malware incidents, particularly widespread ones.

关键词：恶意软件；个人电脑；便携式设备；预防

查看摘要 索取原文[47页]

Scientists have dreamed of information systems with cognitive human- like skills for years. However, constrained by the device characteristics and rapidly increasing design complexity under the traditional processing technology, little progress has been made in hardware implementation. The recently popularized memristor offers a potential break-through for neuromorphic computing because of its unique properties including nonvolatility extremely high fabrication density, and sensitivity to historic voltage/current behavior. In this project, we first investigated the memristor-based synapse design and the corresponding training scheme. Then, the design optimization and its implementation in multi-synapse systems were analyzed too. With the aid of a sharing training circuit and self-training mode, the performance and energy can be significantly improved. At last, a case study of an arithmetic logic unit (ALU) was designed to demonstrate the hardware implementation of a reconfigurable system built based on memristor synapses. All the circuit design, simulation, layout, and functionality verifications have been completed.

关键词：计算机体系结构；自适应系统；运算单元；电路；信息系统

查看摘要 索取原文[37页]

The main purpose of the Coordinated Infrastructure for Fault Tolerance in Systems initiative has been to conduct research with a goal of providing end-to-end fault tolerance on a systemwide basis for applications and other system software. While fault tolerance has been an integral part of most high-performance computing (HPC) system software developed over the past decade, it has been treated mostly as a collection of isolated stovepipes. Visibility and response to faults has typically been limited to the particular hardware and software subsystems in which they are initially observed. Little fault information is shared across subsystems, allowing little flexibility or control on a system-wide basis, making it practically impossible to provide cohesive end-to-end fault tolerance in support of scientific applications. As an example, consider faults such as communication link failures that can be seen by a network library but are not directly visible to the job scheduler, or consider faults related to node failures that can be detected by system monitoring software but are not inherently visible to the resource manager. If information about such faults could be shared by the network libraries or monitoring software, then other system software, such as a resource manager or job scheduler, could ensure that failed nodes or failed network links were excluded from further job allocations and that further diagnosis could be performed. As a founding member and one of the lead developers of the Open MPI project, our efforts over the course of this project have been focused on making Open MPI more robust to failures by supporting various fault tolerance techniques, and using fault information exchange and coordination between MPI and the HPC system software stackfrom the application, numeric libraries, and programming language runtime to other common system components such as jobs schedulers, resource managers, and monitoring tools.

关键词：容错计算机；计算机硬件；计算机软件；计算机控制系统

查看摘要 索取原文[19页]

The armed forces of many North Atlantic Treaty Organization (NATO) members and other nations have used ballistic meteorological (MET) messages for surface to surface trajectories (METB3s) for many decades. It was developed before users had ready access to computers on the battlefield and is normally applied in a manual mode. The later computer MET message (METCM) came into use, as the name implies, after the advent of battlefield computers and continues to be widely used. Some newer artillery MET systems no longer generate METB3s since modern fire control systems use METCMs, and in some NATO nations, the more recent gridded MET message (METGM). Nevertheless, for certain applications and as a backup, there is a requirement to be able to produce a METB3 from a METCM generated locally or transmitted from another artillery MET system. This report briefly discusses a program that converts a METCM into a METB3, which can be applied to specific systems with appropriate modifications, and outlines a modified version for a handheld device. The program applies methods found in available field manuals and NATO publications. Some of the algorithms embodied in the program were extracted from a similar spreadsheet-based method developed at the Armament Research, Development and Engineering Center (ARDEC).

关键词：弹道；计算机；信息处理；火炮

查看摘要 索取原文[28页]

The major components of the Ballistics Research Laboratory Computer- Aided Design (BRL-CAD) Package are reviewed. The BRL-CAD Package is a combinatorial solid geometry based modeling system which includes an interactive model editor, a ray tracing library, a generic framebuffer library, and a large collection of related tools. An object-oriented ray tracing library provides the primary method of model interrogation. A whole family of engineering analysis applications based on the ray tracing paradigm has been built, including traditional renderers and predictive radar models. A generic framebuffer library interface with transparent networking capability provides hardware independent access to any display device from any host. Several categories of software tools for image display, manipulation, and analysis are discussed. Some general user interface issues are mentioned. This paper emphasizes the reasons which led to the system as is exists today, and comments on some of its various strengths and weaknesses.

关键词：弹道；计算机辅助设计；相互作用；讯问

查看摘要 索取原文[14页]

A system was developed in a laboratory on a desktop computer to evaluate armor health. The system uses sensors embedded in the armor which causes the armor to vibrate. There are subtle changes in the vibration pattern if the armor has been damaged. The system uses these changes to diagnose armor health. The goal of the team was to take this application and transfer it to the field where it would be embedded in a portable system that could be readily used by soldiers.

关键词：计算机程序；微型计算机；算法；装甲；检测

查看摘要 索取原文[14页]

As part of NASA's Avionics Steering Committee's stated goal to advance the avionics discipline ahead of program and project needs, the committee initiated a multi-Center technology roadmapping activity to create a comprehensive avionics roadmap. The roadmap is intended to strategically guide avionics technology development to effectively meet future NASA missions needs. The scope of the roadmap aligns with the twelve avionics elements defined in the ASC charter, but is subdivided into the following five areas: Foundational Technology (including devices and components), Command and Data Handling, Spaceflight Instrumentation, Communication and Tracking, and Human Interfaces.

关键词：航空电子设备；指挥和控制；航天器仪表

查看摘要 索取原文[40页]