System engineering practices for complex systems and networks now require that requirement, architecture, and concept of operations product development teams, simultaneously harmonize their activities to provide timely, useful and cost-effective products. When dealing with complex systems of systems, traditional systems engineering methodology quickly falls short of achieving project objectives. This approach is encumbered by the use of a number of disparate hardware and software tools, spreadsheets and documents to grasp the concept of the network design and operation. In case of NASA's space communication networks, since the networks are geographically distributed, and so are its subject matter experts, the team is challenged to create a common language and tools to produce its products. Using Model Based Systems Engineering methods and tools allows for a unified representation of the system in a model that enables a highly related level of detail. To date, Program System Engineering (PSE) team has been able to model each network from their top-level operational activities and system functions down to the atomic level through relational modeling decomposition. These models allow for a better understanding of the relationships between NASA's stakeholders, internal organizations, and impacts to all related entities due to integration and sustainment of existing systems. Understanding the existing systems is essential to accurate and detailed study of integration options being considered. In this paper, we identify the challenges the PSE team faced in its quest to unify complex legacy space communications networks and their operational processes. We describe the initial approaches undertaken and the evolution toward model based system engineering applied to produce Space Communication and Navigation (SCaN) PSE products. We will demonstrate the practice of Model Based System Engineering applied to integrating space communication networks and the summary of its results and impact. We will highlight the insights gained by applying the Model Based System Engineering and provide recommendations for its applications and improvements.

关键词：航天通信，通信网络;系统工程;数据集成;系统集成;体系结构

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关键词：团购；市场规模；扩大

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Since publishing the Great Lakes Networks first communication plan, science communication, particularly in the National Park Services Inventory and Monitoring program, has taken root and become an integral part of our work. Our first communication plan was necessarily broad in its goals and objectives because we were learning what was needed by parks and how we would fulfill those needs. We have been relatively successful in our efforts. In a 2011 survey of staff at the nine Network parks, 78of respondents said they were aware of Network monitoring programs being carried out in their parks. Thus, the goals and objectives in this plan are not much different than they were in 2009, but by achieving the four goals we have set in this version, we should improve upon the flow of information and diversify how it is presented. We are striving to clarify the relevance of our data to park management, strengthen the relationships between the Network and park interpreters, and to begin using social media and webinar technology. As always, we will evaluate our work towards these goals and continue improving how we work with and assist the Great Lakes Network parks.

关键词：沟通计划;网络;通信;监控

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U.S. Army leaders acknowledge the importance of the Human Domain, and it is therefore in the Army's best interest to retain the capabilities and knowledge built over the past 12 years. Failure to maintain these capabilities will inevitably mean redeveloping them during the next conflict at the cost of national treasure, e.g. American lives and dollars. Historically, the Army's improvements in process and technique draw directly from lessons learned in conflict. However, there is value in looking at empirical research drawn from fields with relevant parallels to practices used by influence operators. Within academia, there exists a vast amount of research on techniques and procedures influence operators can utilize. This study sought to identify how Army influence operators can benefit from outside institutions, and not rely solely on our experiences to further our capabilities. Therefore, this paper looked at what mass communication, advertising, and marketing research influence operators can adapt and implement at the strategic and operational levels of war. As a result, this study identified four reinforcing takeaways from the academic literature and two distinct recommendations for implementation, an additional step in the doctrinal process and training for our influence operators in communication strategy design that better supports the military campaign.

关键词：大众传播；广告；传播策略；通信

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This report presents and demonstrates a methodology for analyzing the frequency diversity dependency of a transmitted signal as a function of evaporation duct heights. The integrated Advanced Propagation (APM) module is used to compute maritime signal propagation loss, and a Nakagami-m model is used to model the fading channel. Several approaches for evaluating intermittent communications in maritime environments were presented and demonstrated. The authors show how the Navy-validated APM in combination with an effective channel model can predict maritime communications. Using this approach, simulation results showing the impact of evaporation ducts' wideband frequency diversity, as well as communication links states are presented. These types of analyses have very important applications in mission planning, and are a promising solution that can provide enhanced communication autonomy in unmanned maritime vehicles.

关键词：宽带，遥控飞行器；传输损耗；自主导航；电磁波的传播

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Advancing technologies in smallsats provide remote sensing and communications capabilities achievable with a constellation of satellites at a reasonable cost to meet military needs. Like any other nation looking for a cheap but effective solution in that area, Turkey might also benefit from a replacement of its remote sensing assets. Currently, Turkish Armed Forces rely on a limited number of reconnaissance aircraft and Unmanned Aerial Vehicles, which do not provide real-time or near real-time remote sensing capabilities. Near real-time remote sensing needs for the Turkish warfighter dictates that the Turkish Armed Forces reach that capability as soon as possible. Likewise, replacing its conventional communication radios with satellite communication devices would also fulfill its warfighter needs. While current communication devices have physical limitations in Turkey's mountainous terrain and the surrounding seas, satellite communication capability would provide a wider coverage, and for specific frequencies, it might provide better resistance to jamming and interference. For the benefit of the Turkish Armed Forces' communications needs, a satellite constellation must be optimized such that effective coverage will be achieved with the least number of satellites to provide a reasonable cost. In this study, satellite constellation optimization for the Turkish Armed Forces will be achieved using Analytical Graphics, Inc.'s Systems Tool Kit software for simulation and analysis of several possible communications and remote sensing satellite constellations covering Turkish territory and surrounding seas. The Concept of Operations (CONOPS) for a smallsat constellation will be described and an optimized smallsat constellation will be modeled using STK software. The resulting data will be analyzed and discussed in the form of a recommendation that would benefit the Turkish Armed Forces.

关键词：远程探测；卫星通讯；卫星星座；通信卫星

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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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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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关键词：计算机通讯;计算机安全；计算机软件；网络安全；网络空间

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