We conducted this review to determine the merits of an allegation that VA was transmitting sensitive data, including Personally Identifiable Information (PII) and internal network routing information, over unencrypted telecommunications carrier networks. The VA Midwest Health Care Network, also known as the Veterans Integrated Service Network (VISN) 23 within the Veterans Health Administration, serves more than 400,000 veterans enrolled to receive medical care residing in Iowa, Minnesota, Nebraska, North Dakota, South Dakota and portions of Illinois, Kansas, Missouri, Wisconsin, and Wyoming. In May 2012, a complainant contacted the VA Office of Inspector General (OIG) Hotline, alleging that certain VA medical centers (VAMCs) were transmitting sensitive information, including PII and internal network routing information, over unencrypted telecommunications carrier networks. More specifically, the complainant indicated that unencrypted data were transmitted among various VAMC networks using the South Dakota Network, which functions as the local telecommunications carrier network.The complainant alleged that these security violations occurred at VAMCs located in Fort Meade, SD; Omaha, NE; and Sioux Falls, SD, which are in VISN 23. To determine the merits of this Hotline allegation, we visited the three VAMCs identified in the complaint letter. We interviewed VA's Office of Information and Technology (OIT) personnel to gain an understanding of existing data transmission practices and associated controls.

关键词：通信网络;计算机通讯;指控;计算机安全;数据传输

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NASA has developed an experimental flight payload (referred to as the Space Communication and Navigation (SCAN) Test Bed) to investigate software defined radio (SDR) communications, networking, and navigation technologies, operationally in the space environment. The payload consists of three software defined radios each compliant to NASAs Space Telecommunications Radio System Architecture, a common software interface description standard for software defined radios. The software defined radios are new technology developments underway by NASA and industry partners launched in 2012. The payload is externally mounted to the International Space Station truss to conduct experiments representative of future mission capability. Experiment operations include in-flight reconfiguration of the SDR waveform functions and payload networking software. The flight system will communicate with NASAs orbiting satellite relay network, the Tracking and Data Relay Satellite System at both S-band and Ka-band and to any Earth-based compatible S-band ground station. The system is available for experiments by industry, academia, and other government agencies to participate in the SDR technology assessments and standards advancements.

关键词：航天通信；通信卫星；无线电通信；试验台

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Dense LU factorization is a prominent benchmark used to rank the performance of supercomputers. Many implementations use block-cyclic distributions of matrix blocks onto a two-dimensional process grid. The process grid dimensions drive a trade-off between communication and computation and are architecture- and implementation-sensitive. The critical panel factorization steps can be made less communication-bound by overlapping asynchronous collectives for pivoting with the computation of rank-k updates. By shifting the computation-commun icationtrade-off, a modified block-cyclic distribution can beneficially exploitmore available parallelism on the critical path, and reduce panel factorizations memory hierarchy contention on now-ubiquitous multicore architectures.

关键词：基准;通讯;计算机体系结构;超级计算机

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Engineering a city-wide ubiquitous computing system requires a comprehensive understanding of urban infrastructure including physical motorways, vehicular traffic, and human activities. Many world cities were built at different time periods and with different purposes that resulted in diversified structures and characteristics, which have to be carefully considered while designing ubiquitous computing facilities. In this paper, we propose a novel technique to study global urban infrastructure, with enabling city-wide ubiquitous computing as the aim, using a massive data-driven network of planet-scale online web-cameras and a location-based online social network service, Foursquare. Our approach examines six metropolitan regions infrastructure that includes more than 800 locations, 25 million vehicular mobility records, 220k routes, and two million Foursquare check-ins. We evaluate the spatio-temporal correlation in traffic patterns, examine the structure and connectivity in regions, and study the impact of human mobility on vehicular traffic to gain insight for enabling city-wide ubiquitous computing.

关键词：数据库管理，系统工程；计算机通信；计算机模拟；通信和广播系统

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Mobile augmented reality (MAR) may offer new and engaging ways to support consumer participation in health. We report on design-based research into a MAR application for smartphones and tablets, intended to improve public engagement with biomedical research in a specific urban precinct. Following a review of technical capabilities and organizational and locative design considerations, we worked with staff of four research institutes to elicit their ideas about information and interaction functionalities of a shared MAR app. The results were promising, supporting the development of a prototype and initial field testing with these staff. Evidence from this project may point the way toward user-centred design of MAR services that will enable more widespread adoption of the technology in other healthcare and biomedical research contexts.

关键词：增强现实技术；生物医学；移动医疗；医疗保健

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This thesis researched the availability and applicability of using commercial off-the-shelf (COTS) cellular software and smartphone hardware platforms to address future individual communication requirements for the US Navy at sea. The paper presents evidence in favor of incorporation of COTS technology aboard ships to address tactical communications. Individual communication needs facilitated by devices include text, chat, voice, position location information, imagery and map viewing, streaming video, web browsing and e-mail. While all of these identified communication capabilities are currently available in military command and control systems, they presently reside primarily at hardwired workstations requiring large assets to maintain. The paper also studies current research in micro mobile communication networks that have been growing exponentially in the past year including a host of different network types: ad hoc, smartphone, access point, sensor, etc. The paper lays out a solid understanding of all layers of wireless networking and the interactions between them (including physical, data link, medium access control, routing, transport, and application). The topics of security, efficiency, mobility, health risk, scalability, and their unique characteristics in wireless networks are discussed. Finally, the researcher explores advanced architectures, protocols, and satellite support for complex, dynamic, developing recursive network architectures, protocols, and looks at devices for complex, dynamic, high-performance communication in hostile and extremely remote locations such as the high sea.

关键词：人造卫星；商业设备；通信和广播系统；通讯网络

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Ensuring the effectiveness and reliability of communications networks is essential to national security, the economy, and public health and safety. The communications networks (including core and access networks) can be threatened by both natural and human-caused events, including increasingly sophisticated and prevalent cyber-based threats. GAO has identified the protection of systems supporting the nation's critical infrastructure--which includes the communications sector--as a government-wide high-risk area. GAO was asked to (1) identify the roles of and actions taken by key federal entities to help protect communications networks from cyber-based threats, (2) assess what is known about the extent to which cyber incidents affecting the communications networks have been reported to the FCC and DHS, and (3) determine if Defense's pilot programs to promote cybersecurity in the defense industrial base can be used in the communications sector. To do this, GAO focused on core and access networks that support communication services, as well as critical components supporting the Internet. GAO analyzed federal agency policies, plans, and other documents; interviewed officials; and reviewed relevant reports.

关键词：通信；计算机网络；计算机安全

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The Global System for Mobile Communications (GSM) Association predicts that there will be nearly 50 billion connected devices by 2025, nearly ten times the worlds predicted human population. ABI estimates that through 2012, Machine-to-Machine connected devices will grow by 100m units per year by 2012.1 An M2M module uses a device to capture an event (temperature, activation of airbags, etc.), which is relayed through a network, either wireless or wired, to an application, such as a software program, that translates the captured event into meaningful information (e.g., ice warning, crash notification). An M2M device typically converts analog sensor data into internet protocol (IP) packets for transmission over a communications medium. M2M applications are often characterized by the absence of a human decision maker directly controlling communications intensity, frequency and costs, though there are M2M applications in the transportation sector that also require interaction with drivers. M2M devices can be transmitted over a variety of communications mediums including mobile satellite services, cellular networks, and even combinations of carriers and carrier coverage areas across several networks. Hybrid wireless solutions include intermediary devices such as cellular modems connected to an M2M endpoint via wireless local, personal area or near field communications networks such as Wi-Fi, ZigBee, Bluetooth or Radio Frequency Identification (RFID). The most common communications system for M2M in use today in North America is second generation (2G) wireless, using either General Packet Radio Service (GPRS) or Short Message Service (SMS), which uses signaling protocols that set up and tear down voice calls to transmit small amounts of data.

关键词：汽车；通讯；无线通讯；软件程序；移动卫星服务

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关键词：通讯和广播系统；报警系统；信息传播；移动设备

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To improve the efficiency of communications among unmanned systems, the research focused on the novel use of asymmetric polarized MIMO and network availability. The dissertation objective was to maintain the highest network availability for a mobile ad hoc network with heterogeneous communication capabilities. Using a hybrid dual-polarized Rayleigh fading channel model, asymmetric antenna configurations were studied in simulation for bit error rate and capacity. For a 1 x 1 configuration, polarization reciprocity was used to exploit the polarized channel knowledge, thereby maximizing received uplink power. The optimum gains to maximize uplink capacity were also derived for varying channel cross-polarization values. Larger configurations of 2 x 1 and 2 x 2 were investigated, including overlays of orthogonal space-time block coding, which improved diversity performance in the polarized channels. Extending these link results to realistic scenarios with unmanned systems, a reference point group mobility model including large-scale propagation was proposed to compute the network availability. Another scenario detailed robot exploration of unknown environments, which included large-scale path loss models. While deploying the network, the factors of exploration strategies, signal thresholds and routing were shown to impact the availability metric. Lastly, four extensible formation models were analyzed for their influence on network availability.

关键词：无线通信;天线配置;不对称;通道;通信和广播系统;配置

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