854 research outputs found
The NASA master directory: Quick reference guide
This is a quick reference guide to the NASA Master Directory (MD), which is a free, online, multidisciplinary directory of space and Earth science data sets (NASA and non-NASA data) that are of potential interest to the NASA-sponsored research community. The MD contains high-level descriptions of data sets, other data systems and archives, and campaigns and projects. It provides mechanisms for searching for data sets by important criteria such as geophysical parameters, time, and spatial coverage, and provides information on ordering the data. It also provides automatic connections to a number of data systems such as the NASA Climate Data System, the Planetary Data System, the NASA Ocean Data System, the Pilot Land Data System, and others. The MD includes general information about many data systems, data centers, and coordinated data analysis projects, It represents the first major step in the Catalog Interoperability project, whose objective is to enable researchers to quickly and efficiently identify, obtain information about, and get access to space and Earth science data. The guide describes how to access, use, and exit the MD and lists its features
Development of a virtual personal video recorder based on a set top box
Estágio realizado na Fraunhofer Portugal ResearchTese de mestrado integrado. Engenharia Electrotécnica e de Computadores (Major Telecomunicações). Faculdade de Engenharia. Universidade do Porto. 200
QoS SOLUTIONS FORVIDEOCONFERENCING
This project is intended to gain knowledge and apply the theory leamt about the need of
QoS in videoconferencing and the various options available. Today's conferencing
applications are now IP friendly, it can run on either dedicated lines (like ISDN or
telephone lines) or IP networks. However, as most network administrators know,
conferencingapplications can wreak havoc on unprepared corporate networks. The key to
successfully deploying conferencing applications is the activation of Quality of Service
(QoS). QoS refers to a network's ability to reliably and consistently provide a certain
level of throughput and performance. QoS for conferencing typically involves network
availability, bandwidth, end-to-end delay, jitter, and packet loss. Simply stated, if the
network doesn't conform to the minimum requirements in any of these areas, the
conferences are doomed to fail. QoS can be achieved in a variety of ways, including
over-provisioning (deploying additional bandwidth), data prioritization, and the use of
QoS-enabled overlay or converged networks. Organizations have two main options for
deploying QoS within their organizations; convergence or overlay. Convergence requires
the use of QoS-capable WAN links throughout the organization. In many cases, this
requires a fork-lift upgrade and migration of all network resources, which can place
convergence out of reach of many cost-sensitive organizations. On the other hand,
overlay networks allow a step-by-step migration from a non-QoS to a QoS network
without the high cost and inherent risk of major network reconfigurations. In this way,
overlay networks are a first step toward convergenc
Proceedings of the Second Annual NASA Science Internet User Working Group Conference
Copies of the agenda, list of attendees, meeting summaries, and all presentations and exhibit material are contained. Included are plenary sessions, exhibits of advanced networking applications, and user subgroup meetings on NASA Science Internet policy, networking, security, and user services and applications topics
A framework for usage management
This thesis proposes a formal framework for usage management in distributed systems. The principles of system design are applied in order to standardize certain features of the framework, such as the operational semantics, and leave free of standards areas that necessitate choice and innovation. The framework enables use of multiple policy languages, and dynamic interpretation of usage policies in different computing environments. In addition, the framework provides formal semantics to reason about interoperability of policies with respect to computing environments. The use of this framework in different usage management scenarios is demonstrated including multi-level security, cloud computing and digital rights management (DRM) systems. Furthermore, DRM is cast in a setting that allows the modeling of a number of current approaches within a game theoretic setting. Current strategies that attempt to influence the outcome of such games are analyzed, and a new type of architectural infrastructure that makes novel use of a trust authority is considered in order to create a suitable environment for constructing DRM games that may prove useful in the future
OSI in the NASA science internet: An analysis
The Open Systems Interconnection (OSI) protocol suite is a result of a world-wide effort to develop international standards for networking. OSI is formalized through the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC). The goal of OSI is to provide interoperability between network products without relying on one particular vendor, and to do so on a multinational basis. The National Institute for Standards and Technology (NIST) has developed a Government OSI Profile (GOSIP) that specified a subset of the OSI protocols as a Federal Information Processing Standard (FIPS 146). GOSIP compatibility has been adopted as the direction for all U.S. government networks. OSI is extremely diverse, and therefore adherence to a profile will facilitate interoperability within OSI networks. All major computer vendors have indicated current or future support of GOSIP-compliant OSI protocols in their products. The NASA Science Internet (NSI) is an operational network, serving user requirements under NASA's Office of Space Science and Applications. NSI consists of the Space Physics Analysis Network (SPAN) that uses the DECnet protocols and the NASA Science Network (NSN) that uses TCP/IP protocols. The NSI Project Office is currently working on an OSI integration analysis and strategy. A long-term goal is to integrate SPAN and NSN into one unified network service, using a full OSI protocol suite, which will support the OSSA user community
Communication Architecture For Distributed Interactive Simulation (CADIS): Military Standard (draft)
Report establishes the requirements for the communication architecture to be used in a distributed interactive simulation, including the standards and the recommended practices for implementing the communication architecture and the rationales behind them
System for acquisition, processing and presentation of energy consumption
Tese de mestrado integrado. Engenharia Electrotécnica e de Computadores (Major Telecomunicações). Faculdade de Engenharia. Universidade do Porto. 200
The SIMBAD astronomical database
Simbad is the reference database for identification and bibliography of
astronomical objects. It contains identifications, `basic data', bibliography,
and selected observational measurements for several million astronomical
objects. Simbad is developed and maintained by CDS, Strasbourg. Building the
database contents is achieved with the help of several contributing institutes.
Scanning the bibliography is the result of the collaboration of CDS with
bibliographers in Observatoire de Paris (DASGAL), Institut d'Astrophysique de
Paris, and Observatoire de Bordeaux. When selecting catalogues and tables for
inclusion, priority is given to optimal multi-wavelength coverage of the
database, and to support of research developments linked to large projects. In
parallel, the systematic scanning of the bibliography reflects the diversity
and general trends of astronomical research.
A WWW interface to Simbad is available at: http://simbad.u-strasbg.fr/SimbadComment: 14 pages, 5 Postscript figures; to be published in A&A
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