WorldWideScience

Sample records for satellite education network

  1. An access alternative for mobile satellite networks

    Science.gov (United States)

    Wu, W. W.

    1988-05-01

    Conceptually, this paper discusses strategies of digital satellite communication networks for a very large number of low density traffic stations. These stations can be either aeronautical, land mobile, or maritime. The techniques can be applied to international, domestic, regional, and special purpose satellite networks. The applications can be commercial, scientific, military, emergency, navigational or educational. The key strategy is the use of a non-orthogonal access method, which tolerates overlapping signals. With n being either time or frequency partitions, and with a single overlapping signal allowed, a low cost mobile satellite system can be designed with n squared (n squared + n + 1) number of terminals.

  2. A satellite based global education system: The Knowledge Network of the World

    Science.gov (United States)

    Pelton, Joseph N.

    Today the entire world is struggling to meet the educational needs of more people than ever before. Nearly every country, and especially the developing world has a current and projected shortage of qualified teachers at all educational levels. As a result, there is little likelihood that the necessary educational resources of traditional approaches can be mustered to meet the clearly identified global needs. This paper expands upon a visionary proposal by Arthur C. Clarke for the development and implementation of an electronic tutor. It is demonstrated that the realization of this idea is both technologically and economically feasible and capable of addressing the educational dilemma in an economically viable fashion. Developmental design, operational cost factors are explored together with forecasts for implementation of the electronic tutor unit and the infrastructure required to provide a truly global educational capability by the year 2000. This electronic tutor system is characterized as the key element within a new Knowledge Network of the World (KNOW).

  3. Satellite Upper Air Network (SUAN)

    Science.gov (United States)

    Reale, Tony L.; Thorne, Peter

    2004-10-01

    During the past 20 years of NOAA operational polar satellites, it has become evident that a growing problem concerning their utilization in Climate and also Numerical Weather Prediction (NWP) applications are the systematic errors and uncertainties inherent in the satellite measurements. Similar arguments can be made for global radiosonde observations. These uncertainties are often larger than the sensitive signals and processes, that satellite and radiosonde measurements are designed to reveal, particularly in the realm of climate. Possible strategies to quantify and compensate for these problems include the analysis of satellite overlap data and/or available collocations of satellite and ground truth (radiosonde) observations. However, overlap observations are typically not available except in extreme polar regions and current sampling strategies for compiling collocated radiosonde and satellite observations are insufficient, further compounding the inherent uncertainties in the ground-truth radiosonde data. A Satellite Upper Air Network is proposed to provide reference radiosonde launches coincident with operational polar satellite(s) overpass. The SUAN consist of 36 global radiosonde stations sub-sampled from the Global Upper Air Network (GUAN), and is designed to provide a robust, global sample of collocated radiosonde and satellite observations conducive to the monitoring and validation of satellite and radiosonde observations. The routine operation of such a network in conjunction with operational polar satellites would provide a long-term of performance for critical observations of particular importance for climate. The following report presents a candidate network of 36 upper-air sites that could comprise a SUAN. Their selection along with the mutual benefit across the satellite, radiosonde, climate, numerical weather prediction (NWP) and radiative transfer (RT) model areas are discussed.

  4. Multicast Routing in Satellite Network

    Institute of Scientific and Technical Information of China (English)

    郭惠玲; 宋姝; 李磊; 刘志涛; 郭鹏程

    2004-01-01

    There are some problems in the dual-layer satellite MPLs metworks to be composed of LEO and MEO. In order to solve the problems, this paper presents a plan by means of unicast LSP to implement multicast in the dual-layer satellite MPLs networks. It has advantages of saving space and reducing extra charge.

  5. Satellite Communication and Long Distance Education

    Directory of Open Access Journals (Sweden)

    Hafied Cangara

    2016-02-01

    Full Text Available Since Indonesia introduced communication satellite for telecommunication network, the satellite has brought a number of advantages for national development in various areas, such as telephone network, mass media development, business, education, politics, security and national defence as well as regional and international cooperation. In education, satellite communication could be used for long-distance learning as implemented by 13 state universities in eastern parts of Indonesia. It is also possible to develop the Open University System in teaching and learning process, particularly since the internet technology has been intensively used

  6. Space industrialization - Education. [via communication satellites

    Science.gov (United States)

    Joels, K. M.

    1978-01-01

    The components of an educational system based on, and perhaps enhanced by, space industrialization communications technology are considered. Satellite technology has introduced a synoptic distribution system for various transmittable educational media. The cost of communications satellite distribution for educational programming has been high. It has, therefore, been proposed to utilize Space Shuttle related technology and Large Space Structures (LSS) to construct a system with a quantum advancement in communication capability and a quantum reduction in user cost. LSS for communications purposes have three basic advantages for both developed and emerging nations, including the ability to distribute signals over wide geographic areas, the reduced cost of satellite communications systems versus installation of land based systems, and the ability of a communication satellite system to create instant educational networks.

  7. Gigabit Satellite Network for NASA's Advanced Communication Technology Satellite (ACTS)

    Science.gov (United States)

    Hoder, Douglas; Bergamo, Marcos

    1996-01-01

    The advanced communication technology satellite (ACTS) gigabit satellite network provides long-haul point-to-point and point-to-multipoint full-duplex SONET services over NASA's ACTS. at rates up to 622 Mbit/s (SONET OC-12), with signal quality comparable to that obtained with terrestrial fiber networks. Data multiplexing over the satellite is accomplished using time-division multiple access (TDMA) techniques coordinated with the switching and beam hopping facilities provided by ACTS. Transmissions through the satellite are protected with Reed-Solomon encoding. providing virtually error-free transmission under most weather conditions. Unique to the system are a TDMA frame structure and satellite synchronization mechanism that allow: (a) very efficient utilization of the satellite capacity: (b) over-the-satellite dosed-loop synchronization of the network in configurations with up to 64 ground stations: and (c) ground station initial acquisition without collisions with existing signalling or data traffic. The user interfaces are compatible with SONET standards, performing the function of conventional SONET multiplexers and. as such. can be: readily integrated with standard SONET fiber-based terrestrial networks. Management of the network is based upon the simple network management protocol (SNMP). and includes an over-the-satellite signalling network and backup terrestrial internet (IP-based) connectivity. A description of the ground stations is also included.

  8. Satellite communications network design and analysis

    CERN Document Server

    Jo, Kenneth Y

    2011-01-01

    This authoritative book provides a thorough understanding of the fundamental concepts of satellite communications (SATCOM) network design and performance assessments. You find discussions on a wide class of SATCOM networks using satellites as core components, as well as coverage key applications in the field. This in-depth resource presents a broad range of critical topics, from geosynchronous Earth orbiting (GEO) satellites and direct broadcast satellite systems, to low Earth orbiting (LEO) satellites, radio standards and protocols.This invaluable reference explains the many specific uses of

  9. Satellite ATM Networks: Architectures and Guidelines Developed

    Science.gov (United States)

    vonDeak, Thomas C.; Yegendu, Ferit

    1999-01-01

    An important element of satellite-supported asynchronous transfer mode (ATM) networking will involve support for the routing and rerouting of active connections. Work published under the auspices of the Telecommunications Industry Association (http://www.tiaonline.org), describes basic architectures and routing protocol issues for satellite ATM (SATATM) networks. The architectures and issues identified will serve as a basis for further development of technical specifications for these SATATM networks. Three ATM network architectures for bent pipe satellites and three ATM network architectures for satellites with onboard ATM switches were developed. The architectures differ from one another in terms of required level of mobility, supported data rates, supported terrestrial interfaces, and onboard processing and switching requirements. The documentation addresses low-, middle-, and geosynchronous-Earth-orbit satellite configurations. The satellite environment may require real-time routing to support the mobility of end devices and nodes of the ATM network itself. This requires the network to be able to reroute active circuits in real time. In addition to supporting mobility, rerouting can also be used to (1) optimize network routing, (2) respond to changing quality-of-service requirements, and (3) provide a fault tolerance mechanism. Traffic management and control functions are necessary in ATM to ensure that the quality-of-service requirements associated with each connection are not violated and also to provide flow and congestion control functions. Functions related to traffic management were identified and described. Most of these traffic management functions will be supported by on-ground ATM switches, but in a hybrid terrestrial-satellite ATM network, some of the traffic management functions may have to be supported by the onboard satellite ATM switch. Future work is planned to examine the tradeoffs of placing traffic management functions onboard a satellite as

  10. The Communications Satellite as Educational Tool.

    Science.gov (United States)

    Long, Peter

    1982-01-01

    Drawing on the experiences of several countries, the author describes satellite technology, discusses the feasibility of satellite use in traditional educational institutions, and analyzes the role of satellites in social development. (SK)

  11. Satellite Networks: Architectures, Applications, and Technologies

    Science.gov (United States)

    Bhasin, Kul (Compiler)

    1998-01-01

    Since global satellite networks are moving to the forefront in enhancing the national and global information infrastructures due to communication satellites' unique networking characteristics, a workshop was organized to assess the progress made to date and chart the future. This workshop provided the forum to assess the current state-of-the-art, identify key issues, and highlight the emerging trends in the next-generation architectures, data protocol development, communication interoperability, and applications. Presentations on overview, state-of-the-art in research, development, deployment and applications and future trends on satellite networks are assembled.

  12. Satellite Tracking Astrometric Network (STAN)

    Science.gov (United States)

    Vecchiato, Alberto; Gai, Mario

    2015-08-01

    The possibility of precise orbit tracking and determination of different types of satellites has been explored for at least some 25 years (Arimoto et al., 1990). Proposals in this sense made use mainly of astrometric observations, but multiple tracking techniques combining transfer and laser ranging was also suggested (Guo et al., 2009; Montojo et al., 2011), with different requirements and performances ranging from $\\sim100$~m to tenths of meters.In this work we explore the possible improvements and a novel implementation of a technique relying on large angle, high precision astrometry from ground for the determination of satellite orbits. The concept is based on combined observation of geostationary satellites and other near-Earth space objects from two or more telescopes, applying the triangulation principle over widely separated regions of the sky. An accuracy of a few $10^{-2}$~m can be attained with 1-meter-class telescopes and a field of vied of some arcminutes.We discuss the feasibility of the technique, some of the implementation aspects, and the limitations imposed by atmospheric turbulence. The potential benefits for satellite orbit control and navigation systems are presented, depending on the number and position of the contributing telescopes.We also discuss the possibility that, by reversing the roles of stars and satellites, the same kind of observations can be used for verification and maintenance of astrometric catalogs.

  13. Future large broadband switched satellite communications networks

    Science.gov (United States)

    Staelin, D. H.; Harvey, R. R.

    1979-01-01

    Critical technical, market, and policy issues relevant to future large broadband switched satellite networks are summarized. Our market projections for the period 1980 to 2000 are compared. Clusters of switched satellites, in lieu of large platforms, etc., are shown to have significant advantages. Analysis of an optimum terrestrial network architecture suggests the proper densities of ground stations and that link reliabilities 99.99% may entail less than a 10% cost premium for diversity protection at 20/30 GHz. These analyses suggest that system costs increase as the 0.6 power of traffic. Cost estimates for nominal 20/30 GHz satellite and ground facilities suggest optimum system configurations might employ satellites with 285 beams, multiple TDMA bands each carrying 256 Mbps, and 16 ft ground station antennas. A nominal development program is outlined.

  14. Congestion control and routing over satellite networks

    Science.gov (United States)

    Cao, Jinhua

    Satellite networks and transmissions find their application in fields of computer communications, telephone communications, television broadcasting, transportation, space situational awareness systems and so on. This thesis mainly focuses on two networking issues affecting satellite networking: network congestion control and network routing optimization. Congestion, which leads to long queueing delays, packet losses or both, is a networking problem that has drawn the attention of many researchers. The goal of congestion control mechanisms is to ensure high bandwidth utilization while avoiding network congestion by regulating the rate at which traffic sources inject packets into a network. In this thesis, we propose a stable congestion controller using data-driven, safe switching control theory to improve the dynamic performance of satellite Transmission Control Protocol/Active Queue Management (TCP/AQM) networks. First, the stable region of the Proportional-Integral (PI) parameters for a nominal model is explored. Then, a PI controller, whose parameters are adaptively tuned by switching among members of a given candidate set, using observed plant data, is presented and compared with some classical AQM policy examples, such as Random Early Detection (RED) and fixed PI control. A new cost detectable switching law with an interval cost function switching algorithm, which improves the performance and also saves the computational cost, is developed and compared with a law commonly used in the switching control literature. Finite-gain stability of the system is proved. A fuzzy logic PI controller is incorporated as a special candidate to achieve good performance at all nominal points with the available set of candidate controllers. Simulations are presented to validate the theory. An effocient routing algorithm plays a key role in optimizing network resources. In this thesis, we briefly analyze Low Earth Orbit (LEO) satellite networks, review the Cross Entropy (CE

  15. Satellite utilization for educational communications in the U.S.

    Science.gov (United States)

    Morgan, R. P.; Singh, J. P.

    1974-01-01

    This paper summarizes completed, continuing and planned satellite experiments in the U.S. related to the delivery of educational services and networking. It also describes some results of an on-going study at Washington University directed towards defining applications of fixed/broadcast communication satellites in the U.S. and alternative systems and strategies for large-scale telecommunication-based educational delivery systems utilizing satellites. An analysis is presented of recent actions which may influence future development of such systems.

  16. Applications of Communications Satellites in Higher Education.

    Science.gov (United States)

    Morgan, Robert P.

    Early experiments with the ATS-1 and ATS-3 satellites utilized one way and two way audio for a variety of university purposes, and several different television modes were employed in the ATS-6 satellite. Among the higher education activities on ATS-6 were inservice teacher education and the facilitation of regionalized medical education. A college…

  17. Interim Service ISDN Satellite (ISIS) network model for advanced satellite designs and experiments

    Science.gov (United States)

    Pepin, Gerard R.; Hager, E. Paul

    1991-01-01

    The Interim Service Integrated Services Digital Network (ISDN) Satellite (ISIS) Network Model for Advanced Satellite Designs and Experiments describes a model suitable for discrete event simulations. A top-down model design uses the Advanced Communications Technology Satellite (ACTS) as its basis. The ISDN modeling abstractions are added to permit the determination and performance for the NASA Satellite Communications Research (SCAR) Program.

  18. Satellite Applications for K-12 Geoscience Education

    Science.gov (United States)

    Mooney, M.; Ackerman, S.; Lettvin, E.; Emerson, N.; Whittaker, T. M.

    2007-12-01

    This presentation will highlight interactive on-line curriculum developed at the Cooperative Institute for Meteorological Satellite Studies (CIMSS) at the University of Wisconsin in Madison. CIMSS has been on the forefront of educational software design for over two decades, routinely integrating on-line activities into courses on satellite remote sensing. In 2006, CIMSS began collaborating with education experts and researchers from the University of Washington to create an NSF-funded distance learning course for science teachers called Satellite Applications for Geoscience Education. This course includes numerous web-based learning activities, including a distance education tool called VISITview which allows instructors to connect with multiple students simultaneously to conduct a lesson. Developed at CIMSS to facilitate training of National Weather Service forecasters economically and remotely, VISITview is especially effective for groups of people discussing and analyzing maps or images interactively from many locations. Along with an on-line chat function, VISITview participants can use a speaker phone or a networked voice-enabled application to create a learning environment similar to a traditional classroom. VISITview will be used in two capacities: first, instructors will convey topics of current relevance in geoscience disciplines via VISITview. Second, the content experts will participate in "virtual visits" to the classrooms of the educators who take the course for full credit. This will enable scientists to interact with both teachers and students to answer questions and discuss exciting or inspiring examples that link satellite data to their areas of research. As long as a school has Internet access, an LCD projector and a speakerphone, VISITview sessions can be shared with an entire classroom. The geoscientists who developed material for the course and conducting VISITview lectures include a geologist from the University of Wisconsin-Richland, an

  19. Lymphatic Education & Research Network

    Science.gov (United States)

    Lymphatic Education & Research Network Donate Now Become a Supporting Member X Living with LYMPHEDEMA AND Lymphatic Disease FAQs About ... 261 Madison Avenue, New York, NY 10016 | Lymphatic Education & Research Network is a 501(c)(3) under ...

  20. Design and analysis of the satellite laser communications network

    Science.gov (United States)

    Ren, Pei-an; Qian, Fengchen; Liu, Qiang; Jin, Linlin

    2015-02-01

    A satellite laser communications network structure with two layers and multiple domains has been proposed, which performance has been simulated by OPENT. To simulation, we design several OPNET models of the network's components based on a satellite constellation with two layers and multiple domains, as network model, node model, MAC layer protocol and optical antenna model. The network model consists of core layer and access layer. The core network consists of four geostationary orbit (GEO) satellites which are uniformly distributed in the geostationary orbit. The access network consists of 6 low Earth orbit (LEO) satellites which is the walker delta (walk-δ) constellation with three orbit planes. In access layer, each plane has two satellites, and the constellation is stably. The satellite constellation presented for space laser network can meet the demand of coverage in the middle and low latitude by a few satellites. Also several terminal device models such as the space laser transmitter, receiver, protocol layer module and optical antenna have been designed according to the inter-satellite links in different orbits t from GEO to LEO or GEO to ground. The influence to network of different transmitting throughput, receiving throughput, network protocol and average time delay are simulated. Simulation results of network coverage, connectivity and traffic load performance in different scenes show that the satellite laser network presented by the paper can be fit for high-speed satellite communications. Such analysis can provide effective reference for the research of satellite laser networking and communication protocol.

  1. Network Configuration Analysis for Formation Flying Satellites

    Science.gov (United States)

    Knoblock, Eric J.; Wallett, Thomas M.; Konangi, Vijay K.; Bhasin, Kul B.

    2001-01-01

    The performance of two networks to support autonomous multi-spacecraft formation flying systems is presented. Both systems are comprised of a ten-satellite formation, with one of the satellites designated as the central or 'mother ship.' All data is routed through the mother ship to the terrestrial network. The first system uses a TCP/EP over ATM protocol architecture within the formation, and the second system uses the IEEE 802.11 protocol architecture within the formation. The simulations consist of file transfers using either the File Transfer Protocol (FTP) or the Simple Automatic File Exchange (SAFE) Protocol. The results compare the IP queuing delay, IP queue size and IP processing delay at the mother ship as well as end-to-end delay for both systems. In all cases, using IEEE 802.11 within the formation yields less delay. Also, the throughput exhibited by SAFE is better than FTP.

  2. Networks for Autonomous Formation Flying Satellite Systems

    Science.gov (United States)

    Knoblock, Eric J.; Konangi, Vijay K.; Wallett, Thomas M.; Bhasin, Kul B.

    2001-01-01

    The performance of three communications networks to support autonomous multi-spacecraft formation flying systems is presented. All systems are comprised of a ten-satellite formation arranged in a star topology, with one of the satellites designated as the central or "mother ship." All data is routed through the mother ship to the terrestrial network. The first system uses a TCP/lP over ATM protocol architecture within the formation the second system uses the IEEE 802.11 protocol architecture within the formation and the last system uses both of the previous architectures with a constellation of geosynchronous satellites serving as an intermediate point-of-contact between the formation and the terrestrial network. The simulations consist of file transfers using either the File Transfer Protocol (FTP) or the Simple Automatic File Exchange (SAFE) Protocol. The results compare the IF queuing delay, and IP processing delay at the mother ship as well as application-level round-trip time for both systems, In all cases, using IEEE 802.11 within the formation yields less delay. Also, the throughput exhibited by SAFE is better than FTP.

  3. Satellites for Commonwealth Education: Some Policy Issues. Case Studies: AUSSAT, Australia; Knowledge Network, Canada; INSAT, India; University of the South Pacific; University of the West Indies.

    Science.gov (United States)

    Bates, A. W.

    This report presents case studies on the use of satellites for education in five Commonwealth countries: Australia, Canada, India, Fiji, and Jamaica. Information provided in each of the case studies includes geography, production, the distribution system, regulation and management, and costs. Additional information given for the Australian…

  4. LTE Adaptation for Mobile Broadband Satellite Networks

    Directory of Open Access Journals (Sweden)

    Bastia Francesco

    2009-01-01

    Full Text Available One of the key factors for the successful deployment of mobile satellite systems in 4G networks is the maximization of the technology commonalities with the terrestrial systems. An effective way of achieving this objective consists in considering the terrestrial radio interface as the baseline for the satellite radio interface. Since the 3GPP Long Term Evolution (LTE standard will be one of the main players in the 4G scenario, along with other emerging technologies, such as mobile WiMAX; this paper analyzes the possible applicability of the 3GPP LTE interface to satellite transmission, presenting several enabling techniques for this adaptation. In particular, we propose the introduction of an inter-TTI interleaving technique that exploits the existing H-ARQ facilities provided by the LTE physical layer, the use of PAPR reduction techniques to increase the resilience of the OFDM waveform to non linear distortion, and the design of the sequences for Random Access, taking into account the requirements deriving from the large round trip times. The outcomes of this analysis show that, with the required proposed enablers, it is possible to reuse the existing terrestrial air interface to transmit over the satellite link.

  5. Network coding and its applications to satellite systems

    DEFF Research Database (Denmark)

    Vieira, Fausto; Roetter, Daniel Enrique Lucani

    2015-01-01

    Network coding has its roots in information theory where it was initially proposed as a way to improve a two-node communication using a (broadcasting) relay. For this theoretical construct, a satellite communications system was proposed as an illustrative example, where the relay node would...... be a satellite covering the two nodes. The benefits in terms of throughput, resilience, and flexibility of network coding are quite relevant for wireless networks in general, and for satellite systems in particular. This chapter presents some of the basics in network coding, as well as an overview of specific...... scenarios where network coding provides a significant improvement compared to existing solutions, for example, in broadcast and multicast satellite networks, hybrid satellite-terrestrial networks, and broadband multibeam satellites. The chapter also compares coding perspectives and revisits the layered...

  6. Network coding and its applications to satellite systems

    DEFF Research Database (Denmark)

    Vieira, Fausto; Roetter, Daniel Enrique Lucani

    2015-01-01

    Network coding has its roots in information theory where it was initially proposed as a way to improve a two-node communication using a (broadcasting) relay. For this theoretical construct, a satellite communications system was proposed as an illustrative example, where the relay node would...... be a satellite covering the two nodes. The benefits in terms of throughput, resilience, and flexibility of network coding are quite relevant for wireless networks in general, and for satellite systems in particular. This chapter presents some of the basics in network coding, as well as an overview of specific...... scenarios where network coding provides a significant improvement compared to existing solutions, for example, in broadcast and multicast satellite networks, hybrid satellite-terrestrial networks, and broadband multibeam satellites. The chapter also compares coding perspectives and revisits the layered...

  7. Full Service ISDN Satellite (FSIS) network model for advanced ISDN satellite design and experiments

    Science.gov (United States)

    Pepin, Gerard R.

    1992-01-01

    The Full Service Integrated Services Digital Network (FSIS) network model for advanced satellite designs describes a model suitable for discrete event simulations. A top down model design uses the Advanced Communications Technology Satellite (ACTS) as its basis. The ACTS and the Interim Service ISDN Satellite (ISIS) perform ISDN protocol analyses and switching decisions in the terrestrial domain, whereas FSIS makes all its analyses and decisions on-board the ISDN satellite.

  8. 47 CFR 76.122 - Satellite network non-duplication.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Satellite network non-duplication. 76.122... MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Network Non-duplication Protection, Syndicated Exclusivity and Sports Blackout § 76.122 Satellite network non-duplication. (a) Upon receiving notification pursuant...

  9. An Educator's Guide to Communication Satellite Technology.

    Science.gov (United States)

    Polcyn, Kenneth A.

    Recent developments in the area of sophisticated communications technology present challenges to the imagination of every educator. This guide provides educational planners with an awareness and understanding of communication satellite technology, its current uses, and some of the tentative plans for educational experimentation. The first part…

  10. TUBSAT-1, satellite technology for educational purposes

    Science.gov (United States)

    Ginati, A.

    1988-01-01

    TUBSAT-1 (Technical University of Berlin Satellite) is an experimental low-cost satellite within the NASA Get Away Special (GAS) program. This project is being financed by the German BMFT (Federal Ministry for Research and Technology), mainly for student education. The dimensions and weight are determined by GAS requirements and the satellite will be ejected from the space shuttle into an approximately 300-km circular orbit. It is a sun/star oriented satellite with an additional spin stabilization mode. The first planned payload is to be used for observing flight paths of migratory birds from northern Europe to southern Africa and back.

  11. Integrated Adaptive Analysis and Visualization of Satellite Network Data Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop a system that enables integrated and adaptive analysis and visualization of satellite network management data. Integrated analysis and...

  12. The french educational satellite arsene

    Science.gov (United States)

    Danvel, M.; Escudier, B.

    ARSENE (Ariane, Radio-amateur, Satellite pour l'ENseignement de l'Espace) is a telecommunications satellite for Amateur Space Service. Its main feature is that more than 100 students from French engineering schools and universities have been working since 1979 for definition phase and satellite development. The highest IAF awards has been obtained by "ARSENE students" in Tokyo (1980) and Rome (1981). The French space agency, CNES and French aerospace industries are supporting the program. The European Space Agency offered to place ARSENE in orbit on the first Ariane mark IV launch late 1985.

  13. Satellite communications for the next generation telecommunication services and networks

    Science.gov (United States)

    Chitre, D. M.

    1991-01-01

    Satellite communications can play an important role in provisioning the next-generation telecommunication services and networks, provided the protocols specifying these services and networks are satellite-compatible and the satellite subnetworks, consisting of earth stations interconnected by the processor and the switch on board the satellite, interwork effectively with the terrestrial networks. The specific parameters and procedures of frame relay and broadband integrated services digital network (B-ISDN) protocols which are impacted by a satellite delay. Congestion and resource management functions for frame relay and B-ISDN are discussed in detail, describing the division of these functions between earth stations and on board the satellite. Specific onboard and ground functions are identified as potential candidates for their implementation via neural network technology.

  14. Satellite -Based Networks for U-Health & U-Learning

    Science.gov (United States)

    Graschew, G.; Roelofs, T. A.; Rakowsky, S.; Schlag, P. M.

    2008-08-01

    The use of modern Information and Communication Technologies (ICT) as enabling tools for healthcare services (eHealth) introduces new ways of creating ubiquitous access to high-level medical care for all, anytime and anywhere (uHealth). Satellite communication constitutes one of the most flexible methods of broadband communication offering high reliability and cost-effectiveness of connections meeting telemedicine communication requirements. Global networks and the use of computers for educational purposes stimulate and support the development of virtual universities for e-learning. Especially real-time interactive applications can play an important role in tailored and personalised services.

  15. Models of educational institutions' networking

    OpenAIRE

    Shilova Olga Nikolaevna

    2015-01-01

    The importance of educational institutions' networking in modern sociocultural conditions and a definition of networking in education are presented in the article. The results of research levels, methods and models of educational institutions' networking are presented and substantially disclosed.

  16. Models of educational institutions' networking

    OpenAIRE

    Shilova Olga Nikolaevna

    2015-01-01

    The importance of educational institutions' networking in modern sociocultural conditions and a definition of networking in education are presented in the article. The results of research levels, methods and models of educational institutions' networking are presented and substantially disclosed.

  17. Satellite Meteorology Education & Training Resources from COMET

    Science.gov (United States)

    Abshire, W. E.; Dills, P. N.; Weingroff, M.; Lee, T. F.

    2012-12-01

    The COMET® Program (www.comet.ucar.edu) receives funding from NOAA NESDIS as well as EUMETSAT and the Meteorological Service of Canada to support education and training in satellite meteorology. These partnerships enable COMET to create educational materials of global interest on geostationary and polar-orbiting remote sensing platforms. These materials focus on the capabilities and applications of current and next-generation satellites and their relevance to operational forecasters and other user communities. By partnering with experts from the Naval Research Laboratory, NOAA-NESDIS and its Cooperative Institutes, Meteorological Service of Canada, EUMETSAT, and other user communities, COMET stimulates greater use of satellite data observations and products. This presentation provides an overview of COMET's recent satellite education efforts in the area of polar orbiting satellites. COMET has a new module on Suomi NPP, which describes the satellite system and discusses the improvements that it is bringing to forecasting, numerical weather prediction, and environmental monitoring. COMET has also published an updated version of its module on the VIIRS instrument. "Imaging with VIIRS: A Convergence of Technologies and Experience, 2nd Edition" covers the instrument's enhanced capabilities by examining the systems that contributed to its development. Special attention is paid to the Day/Night Visible channel as VIIRS is the first instrument on a civilian satellite to image atmospheric and terrestrial features with and without moonlight. An upcoming module will exclusively focus on nighttime imaging with the VIIRS Day/Night Band (DNB). "Applications of the VIIRS Day-Night Band" will introduce the capabilities of DNB imagery to a wide audience ranging from forecasters and emergency managers to wildfire fighters and oceanographers. DNB products will be compared to traditional satellite products made from infrared data, including the "fog" product. Users will learn how DNB

  18. Study on Service Level Management in Integrated Satellite Information Network

    Institute of Scientific and Technical Information of China (English)

    SHANG Rui-qiang; ZHAO Jian-li; WANG Guang-xing

    2005-01-01

    Integrated Satellite Information Network (ISIN) includes those nodes in space and those on ground. It is the way to realize the fusion of satellite communication and traditional network technology. A satellite network management system based on Multiplex Network Management Protocol (MNMP) has accomplished traditional management, such as configuration, performance and fault management. An architecture of Service Level Management (SLM) in ISIN is proposed, and a service topology management and Service Level Agreement (SLA) are deeply researched. At last, service security and fault management are briefly discussed, and a simulation system is accomplished.

  19. Expanding Access with Satellite-Enabled Distance Education

    Directory of Open Access Journals (Sweden)

    Qi Wang

    2006-12-01

    Full Text Available Education and training became increasingly critical for citizens of every nation during the last century, and that paradigm will be no less true, throughout the 21st Century. As the world progresses fully into an information society, access to information and to a knowledge-based work force is a precondition for any country to remain competitive. Education, and increasingly distant education (DE, plays a vital role in turning human resources into knowledge workers. Information and communications technologies (ICT have provided new ways to educate and to disseminate information that is crucial for creating these competitive, knowledge-based work forces. Modern DE, enabled by ICT-based networks and the Internet tools, offers great advantages that are leveling the global playing field, in terms of providing access and opportunities for specialized training and education. Using satellite technology in DE may be imperative to developing countries, where the majority of their populations are scattered in rural and remote areas. Where the traditional brick and mortar classrooms cannot easily reach, satellite-powered DE systems can. Through literature review and rational analysis, this paper examines how satellite-assisted DE systems expand education access.

  20. Packet routing algorithm for polar orbit LEO satellite constellation network

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Broadband satellite networks are capable of providing global coverage and support various services. The networks constructed by Low Earth Orbit (LEO) satellite constellations have attracted great interests because of their short round-trip delays and wide bandwidths. A challenging problem is to develop a simple and efficient packet routing algorithm for the LEO satellite constellation network. This paper presents a SpiderWeb Topological Network (SWTN) and a distributed packet routing algorithm for the LEO satellite constellation network based on the SWTN. The algorithm gives the minimum propagation delay paths with low computational complexity and requires no routing tables, which is practical for on-board processing. The performance of the algorithm is demonstrated through simulations.

  1. On Using Satellite-Based Networks for Capacity Building and Education for All: A Case Study of Rajiv Gandhi Project for EduSat-Supported Elementary Education

    Science.gov (United States)

    Chaudhary, Sohanvir; Garg, Suresh

    2010-01-01

    One of the serious problems associated with Indian school education has been high dropout rate. The reasons are many and varied but the major constraints are: non-availability of adequate number of competent and trained teachers in most of the schools and separate room for each class. To overcome such problems and increase equitable access to all,…

  2. Test using communication satellite for security telecommunication network

    Energy Technology Data Exchange (ETDEWEB)

    Kimura, M.

    1988-01-01

    The authors confirmed by their experiment results that the satellite communication could be practically used for remote monitoring and control in gas distribution systems and data communication not only in emergency but also as the reinforced means of communication network. This report deals with the general description of the security communication network, our experiment of satellite operating system, the results and further plan for the practical application. Their company has started the test on the utilization of a communication satellite (CS-2 Japanese domestic communication satellite) since July, 1984, for the purpose of securing the telecommunication network in case of disaster and applying the satellite communications to data communication suitable for the information age, as for a gas utility industry.

  3. Dynamic Characteristics of Inter-Satellite Links in LEO Networks

    Institute of Scientific and Technical Information of China (English)

    王亮; 张乃通; 温萍萍

    2003-01-01

    To establish an efficient inter-satellite link (ISL) in an LEO network, the effect of geometric characteristics of ISL on the ISLs and the devices on the LEO satellite should be examined. Because of the continuous movement of the LEO satellite, the time-varying behaviours of the ISL's geometric charactersistics continuously change with the changes of the satellite's position on the orbit. These dynamic geometric characteristics of the ISLs are important for ISL's performance analyzing and the design of the devices on the LEO satellite. This paper describes dynamic geometric characteristics of ISL, analyzes the impact of these regulations on the tracking system of the satellite's antenna and the power adjusting system of the satellite's transmitter, with the Iridium system as an example.

  4. Transmission Technique towards Seamless Handover for NGEO Satellite Networks

    Institute of Scientific and Technical Information of China (English)

    Wang LU; Liu Lixiang; Hu Xiaohui

    2011-01-01

    This paper presents a seamless transmission technique for Non-Geostationary Earth Orbit (NGEO) satellite networks.The seamless transmission technique combines the concept of Hop-by-Hop and network coding to alleviate the negative impacts of handovers,high bit error rate,and long delay,and to achieve high throughput and complete delivery in NGEO satellite networks.This network coding algorithm is able to maintain expected small queue size and low decoding latency.Furthermore,the seamless transmission technique applies a novel explicit congestion notification mechanism and can achieve high bandwidth utilization.Various aspects of this seamless transmission technique are evaluated.

  5. Advances Made in the Next Generation of Satellite Networks

    Science.gov (United States)

    Bhasin, Kul B.

    1999-01-01

    Because of the unique networking characteristics of communications satellites, global satellite networks are moving to the forefront in enhancing national and global information infrastructures. Simultaneously, broadband data services, which are emerging as the major market driver for future satellite and terrestrial networks, are being widely acknowledged as the foundation for an efficient global information infrastructure. In the past 2 years, various task forces and working groups around the globe have identified pivotal topics and key issues to address if we are to realize such networks in a timely fashion. In response, industry, government, and academia undertook efforts to address these topics and issues. A workshop was organized to provide a forum to assess the current state-of-the-art, identify key issues, and highlight the emerging trends in the next-generation architectures, data protocol development, communication interoperability, and applications. The Satellite Networks: Architectures, Applications, and Technologies Workshop was hosted by the Space Communication Program at the NASA Lewis Research Center in Cleveland, Ohio. Nearly 300 executives and technical experts from academia, industry, and government, representing the United States and eight other countries, attended the event (June 2 to 4, 1998). The program included seven panels and invited sessions and nine breakout sessions in which 42 speakers presented on technical topics. The proceedings covers a wide range of topics: access technology and protocols, architectures and network simulations, asynchronous transfer mode (ATM) over satellite networks, Internet over satellite networks, interoperability experiments and applications, multicasting, NASA interoperability experiment programs, NASA mission applications, and Transmission Control Protocol/Internet Protocol (TCP/IP) over satellite: issues, relevance, and experience.

  6. Distributed Traffic Balancing Routing for LEO Satellite Networks

    Directory of Open Access Journals (Sweden)

    Yong Lu

    2013-11-01

    Full Text Available Satellite networks have been widely investigated both in the business and academia for many years, with many important routing algorithms reported in the literatures. However, fewer existing routing algorithms focus on the trade-off between the routing survivability and the routing computation and storage overheads. Due to topological dynamics, it is difficult to effectively apply the conventional routing protocols such as RIP or OSPF to Low Earth Orbit (LEO satellite networks. According to the virtual topology model based on virtual node, this paper propose a new fully distributed routing protocol for LEO satellite networks, called Distributed Traffic Balancing Routing (DTBR. The proposed protocol not only guarantees the routing survivability and provides the ability of traffic balancing, but also result in few additional computation and storage overheads only deriving from the information flooding of failed satellites. Simulation results demonstrate positive conclusions of our methods.

  7. Dynamic Routing Algorithm for Increasing Robustness in Satellite Networks

    Institute of Scientific and Technical Information of China (English)

    LI Dong-ni; ZHANG Da-kun

    2008-01-01

    In low earth orbit(LEO)and medium earth orbit(MEO)satellite networks,the network topology changes rapidly because of the high relative speed movement of satellites.When some inter-satellite links (ISLs)fail,they can not be repaired in a short time.In order to increase the robustness for LEO/MEO satellite networks,an effective dynamic routing algorithm is proposed.All the routes to a certain node are found by constructing a destination oriented acyclic directed graph(DOADG)with the node as the destination.In this algorithm,multiple routes are provided,loop-free is guaranteed,and as long as the DOADG maintains,it is not necessary to reroute even if some ISLs fail.Simulation results show that comparing to the conventional routing algorithms,it is more efficient and reliable,costs less transmission overhead and converges faster.

  8. Internetworking satellite and local exchange networks for personal communications applications

    Science.gov (United States)

    Wolff, Richard S.; Pinck, Deborah

    1993-01-01

    The demand for personal communications services has shown unprecedented growth, and the next decade and beyond promise an era in which the needs for ubiquitous, transparent and personalized access to information will continue to expand in both scale and scope. The exchange of personalized information is growing from two-way voice to include data communications, electronic messaging and information services, image transfer, video, and interactive multimedia. The emergence of new land-based and satellite-based wireless networks illustrates the expanding scale and trend toward globalization and the need to establish new local exchange and exchange access services to meet the communications needs of people on the move. An important issue is to identify the roles that satellite networking can play in meeting these new communications needs. The unique capabilities of satellites, in providing coverage to large geographic areas, reaching widely dispersed users, for position location determination, and in offering broadcast and multicast services, can complement and extend the capabilities of terrestrial networks. As an initial step in exploring the opportunities afforded by the merger of satellite-based and land-based networks, several experiments utilizing the NASA ACTS satellite and the public switched local exchange network were undertaken to demonstrate the use of satellites in the delivery of personal communications services.

  9. A Minimum Cost Handover Algorithm for Mobile Satellite Networks

    Institute of Scientific and Technical Information of China (English)

    Zhang Tao; Zhang Jun

    2008-01-01

    For mobile satellite networks,an appropriate handover scheme should be devised to shorten handover delay with optimized application of network resources.By introducing the handover cost model of service,this article proposes a rerouting triggering scheme for path optimization after handover and a new minimum cost handover algorithm for mobile satellite networks.This algorithm ensures the quality of service (QoS) parameters,such as delay,during the handover and minimizes the handover costs.Simulation indicates that this algorithm is superior to other current algorithms in guaranteeing the QoS and decreasing handover costs.

  10. SATELLITE OBSERVATIONS FOR EDUCATION OF CLIMATE CHANGE

    Directory of Open Access Journals (Sweden)

    ILONA PAJTÓK-TARI

    2011-03-01

    Full Text Available This paper surveys the key statements of the IPCC (2007 Reportbased mainly on the satellite-borne observations to support teaching climatechange and geography by using the potential of this technology. In theIntroduction we briefly specify the potential and the constraints of remote sensing.Next the key climate variables for indicating the changes are surveyed. Snow andsea-ice changes are displayed as examples for these applications. Testing theclimate models is a two-sided task involving satellites, as well. Validation of theability of reconstructing the present climate is the one side of the coin, whereassensitivity of the climate system is another key task, leading to consequences onthe reality of the projected changes. Finally some concluding remarks arecompiled, including a few ideas on the ways how these approaches can be appliedfor education of climate change.

  11. Designing the next phase domestic satellites - A step to communication satellites as intelligent network nodes

    Science.gov (United States)

    Majus, J.

    1982-09-01

    Applications of satellite systems for telecommunication networks are discussed in terms of harmonizing the satellite capabilities with ground-based equipment, and design for the satellites are discussed. Modern network services are becoming increasingly digitized and use optic fiber switching and information transfer. Spaceborne nodes can be used for telephony, television, packet switching, leased lines, and teletex, with reserved sectors for point-to-point communications. Space systems are capable of 100% coverage, while terrestrial systems frequently have utilization rates near 5%, implying that demand-oriented satellite expansion of local systems is the suitable methodology. Technological requirements are explored, including exclusive use of digital processing, flexible flow rates, signal transmission times, and short time availability.

  12. Next generation communications satellites: multiple access and network studies

    Science.gov (United States)

    Meadows, H. E.; Schwartz, M.; Stern, T. E.; Ganguly, S.; Kraimeche, B.; Matsuo, K.; Gopal, I.

    1982-01-01

    Efficient resource allocation and network design for satellite systems serving heterogeneous user populations with large numbers of small direct-to-user Earth stations are discussed. Focus is on TDMA systems involving a high degree of frequency reuse by means of satellite-switched multiple beams (SSMB) with varying degrees of onboard processing. Algorithms for the efficient utilization of the satellite resources were developed. The effect of skewed traffic, overlapping beams and batched arrivals in packet-switched SSMB systems, integration of stream and bursty traffic, and optimal circuit scheduling in SSMB systems: performance bounds and computational complexity are discussed.

  13. Satellite network robust QoS-aware routing

    CERN Document Server

    Long, Fei

    2014-01-01

    Satellite Network Robust QoS-aware Routing presents a novel routing strategy for satellite networks. This strategy is useful for the design of multi-layered satellite networks as it can greatly reduce the number of time slots in one system cycle. The traffic prediction and engineering approaches make the system robust so that the traffic spikes can be handled effectively. The multi-QoS optimization routing algorithm can satisfy various potential user requirements. Clear and sufficient illustrations are also presented in the book. As the chapters cover the above topics independently, readers from different research backgrounds in constellation design, multi-QoS routing, and traffic engineering can benefit from the book.   Fei Long is a senior engineer at Beijing R&D Center of 54th Research Institute of China Electronics Technology Group Corporation.

  14. Wavelength dimensioning for wavelength-routed WDM satellite network

    Institute of Scientific and Technical Information of China (English)

    Liu Zhe; Guo Wei; Deng Changlin; Hu Weisheng

    2016-01-01

    Internet and broadband applications driven by data traffic demand have become key dri-vers for satellite constellations. The key technology to satisfy the high capacity requirements between satellites is optical satellite networks by means of wavelength division multiplexing inter-satellite links (ISLs) with wavelength routing (WDM-OSN). Due to the limited optical amplifier bandwidth onboard the satellite, it is important to minimize the wavelength requirements to provi-sion requests. However, ISLs should be dynamically established and deleted for each satellite according to its visible satellites. Furthermore, different link assignments will result in different topologies, hence yielding different routings and wavelength assignments. Thus, a perfect match model-based link assignment scheme (LAS-PMM) is proposed to design an appropriate topology such that shorter path could be routed and less wavelengths could be assigned for each ISL along the path. Finally, simulation results show that in comparison to the regular Manhattan street net-work (MSN) topology, wavelength requirements and average end-to-end delay based on the topol-ogy generated by LAS-PMM could be reduced by 24.8%and 12.4%, respectively.

  15. Integration of Quantum Cryptography through Satellite Networks Transmission

    Directory of Open Access Journals (Sweden)

    Skander Aris

    2011-01-01

    Full Text Available Problem statement: The security of the telecommunications satellite has become a crucial issue. The telecommunications can be set using the classical cryptography. But this so-called classical cryptography provides cryptographic security. This means that security is based on the difficulty of some mathematics problems. On the other hand, quantum cryptography provides security without conditions based on the law of quantum physics. This method, called the theoretic information security is evidenced using the theory of information. Approach: In this study, we study whether quantum cryptography can be applied in the frame of the satellite telecommunications network. To do this in our project, we present theories regarding the following issues: Telecommunications Station and Satellite Communication Networks, Quantum Key Distribution, Open Space and Satellites, Analyses in different Scenarios between the Satellite and Earth station. Results: Quantum communications offers many advantages for secure data transmission, in our implementation study, we presented different scenarios of quantum key exchange between satellites and ground stations for possible approach to subsystem with quantum communication in space, capable of generating and detecting entangled photons as well as faint laser pulses. Conclusion: The use of satellites to distribute quantum photon provides a unique solution for long-distance. Moreover, quantum cryptography is a satisfactory solution to improve the safety problem. So, the quantum transmissions are the future of telecommunications.

  16. Satellite link augmentation of ground based packet switched data networks

    Science.gov (United States)

    Farrell, J. B.; McLane, P. J.; Campbell, L. L.

    Use of satellite link augmentation to improve the performance of a packet switched data network is considered. Particular attention is paid to the analysis of two queues in series from the standpoint of time delay. A finite state machine model is used to aid the analysis. The results from the analysis are then used in a flow deviation routing algorithm. This algorithm is applied to study the performance improvement when satellite links are used to augment the Canadian DATAPAC network. The results are backed up by extensive simulations on a digital computer.

  17. Incorporate design of on-board network and inter-satellite network

    Science.gov (United States)

    Li, Bin; You, Zheng; Zhang, Chenguang

    2005-11-01

    In satellite, Data transferring is very important and must be reliable. This paper first introduced an on-board network based on Control Area Network (CAN). As a kind of field bus, CAN is simple and reliable, and has been tested by previous flights. In this paper, the CAN frame is redefined, including the identifier and message data, the addresses for source and destination as well as the frame types. On-board network provides datagram transmission and buffer transmission. Data gram transmission is used to carry out TTC functions, and buffer transmission is used to transfer mass data such as images. Inter-satellite network for satellite formation flying is not designed individually. It takes the advantage of TCP/IP model and inherits and extends on-board network protocols. The inter-satellite network includes a linkage layer, a network layer and a transport layer. There are 8 virtual channels for various space missions or requirements and 4 kinds of services to be selected. The network layer is designed to manage the whole net, calculate and select the route table and gather the network information, while the transport layer mainly routes data, which correspondingly makes it possible for communication between each two nodes. Structures of the linkage frame and transport layer data segment are similar, thus there is no complex packing and unpacking. At last, this paper gives the methods for data conversion between the on-board network and the inter-satellite network.

  18. A Hybrid Satellite-Terrestrial Approach to Aeronautical Communication Networks

    Science.gov (United States)

    Kerczewski, Robert J.; Chomos, Gerald J.; Griner, James H.; Mainger, Steven W.; Martzaklis, Konstantinos S.; Kachmar, Brian A.

    2000-01-01

    Rapid growth in air travel has been projected to continue for the foreseeable future. To maintain a safe and efficient national and global aviation system, significant advances in communications systems supporting aviation are required. Satellites will increasingly play a critical role in the aeronautical communications network. At the same time, current ground-based communications links, primarily very high frequency (VHF), will continue to be employed due to cost advantages and legacy issues. Hence a hybrid satellite-terrestrial network, or group of networks, will emerge. The increased complexity of future aeronautical communications networks dictates that system-level modeling be employed to obtain an optimal system fulfilling a majority of user needs. The NASA Glenn Research Center is investigating the current and potential future state of aeronautical communications, and is developing a simulation and modeling program to research future communications architectures for national and global aeronautical needs. This paper describes the primary requirements, the current infrastructure, and emerging trends of aeronautical communications, including a growing role for satellite communications. The need for a hybrid communications system architecture approach including both satellite and ground-based communications links is explained. Future aeronautical communication network topologies and key issues in simulation and modeling of future aeronautical communications systems are described.

  19. A Network Primer for Educators.

    Science.gov (United States)

    Cornish, Maria; Monahan, Brian

    1996-01-01

    Provides educators with a basic understanding of what networks are and how they can be used in educational settings. Topics include issues, policies, and equipment involved in setting up a network; software; telephone service; a computer facilitator; and the Internet and the World Wide Web for elementary and secondary education. (LRW)

  20. PACKET ROUTING ALGORITHM FOR LEO SATELLITE CONSTELLATION NETWORK

    Institute of Scientific and Technical Information of China (English)

    Wang Kaidong; Tian Bin; Yi Kechu

    2005-01-01

    A novel distributed packet routing algorithm for Low Earth Orbit (LEO) satellite networks based on spiderweb topology is presented. The algorithm gives the shortest path with very low computational complexity and without on-board routing tables, which is suitable and practical for on-board processing. Simulation results show its practicability and feasibility.

  1. Network design tool for EHF satellite communications networks

    Science.gov (United States)

    Norvell, S.; Brown, G. J.

    1983-06-01

    This document describes the design concept of the network design tool. The network design tool (NDT) is a collection of analytical techniques, algorithms and simulation methods that may be used to characterize the performance of a computer communication network. Much work has been done over the past several years in network performance analysis and many techniques have been developed or proposed. Each of these methods applies to a particular aspect of the network design and is based on a particular modeling point of view. We define the computer communication network and then describe the different ways the network may be modeled. Each network model is related to the particular design problem being addressed. The various analytical approaches are briefly described and their relationship to the network models discussed. Chapter 2 is a survey of the major approaches to specific network design problems while chapters 3 and 4 discuss two fairly well defined areas of network analysis: topological design/optimization and protocol validation. Chapter 5 is a survey of network design tools presently available locally or on the advanced research projects agency network (ARPANET). Finally, chapter 6 presents an outline of the NDT specification.

  2. Future integrated broadband fiber, wireless, and satellite networks

    Science.gov (United States)

    Chan, Vincent W. S.

    2006-10-01

    With the increasing technical maturity in fiber, wireless and satellite communication technologies, new horizons are becoming feasible for future broadband networks, providing economical data rates well in excess of Gbps for stationary and mobile users as well as novel applications these advanced network services will permit. This talk explores the future architecture possibilities of such a network using new and radical technology building blocks such as: free space laser communications, multiple access multi-beam data satellite communications, novel all-optical network transport/switching and analog transmission and processing over optical carriers that support coherent distributed platform sensing and communications. We will articulate why we have to design this new network across layers from the Physical Layer to the Network and Transport Layers (even the Application Layer). Not only can future network performance and cost undergo quantum-leap improvements; such a network can have profound transforming effects on space and terrestrial system architectures for sensing, healthcare, early warning systems, disaster relief, research collaborations and other new commercial applications.

  3. Information Networking in Population Education.

    Science.gov (United States)

    United Nations Educational, Scientific, and Cultural Organization, Bangkok (Thailand). Regional Office for Education in Asia and the Pacific.

    The rapidly increasing body of knowledge in population education has created the need for systematic and effective information services. Information networking entails sharing resources so that the information needs of all network participants are met. The goals of this manual are to: (1) instill in population education specialists a more…

  4. Negative Attitudes, Network and Education

    DEFF Research Database (Denmark)

    Bennett, Patrick; la Cour, Lisbeth; Larsen, Birthe

    , the impact of negative attitudes and networking taking into account that these parameters may influence high and uneducated workers as well as immigrants and natives differently, creating different incentives to acquire education for the two ethnic groups. Using rich Danish administrative data, this paper......This paper explores potential explanations behind the educational gap between young natives and immigrants using two measures, negative attitudes towards immigrants and networking, which may influence natives and immigrants differently. The paper considers, both theoretically and empirically...... finds evidence that greater negative attitudes increase incentives for males to acquire education and that networking also increases immigrant education....

  5. Negative Attitudes, Network and Education

    DEFF Research Database (Denmark)

    Bennett, Patrick; la Cour, Lisbeth; Larsen, Birthe;

    This paper explores potential explanations behind the educational gap between young natives and immigrants using two measures, negative attitudes towards immigrants and networking, which may influence natives and immigrants differently. The paper considers, both theoretically and empirically......, the impact of negative attitudes and networking taking into account that these parameters may influence high and uneducated workers as well as immigrants and natives differently, creating different incentives to acquire education for the two ethnic groups. Using rich Danish administrative data, this paper...... finds evidence that greater negative attitudes increase incentives for males to acquire education and that networking also increases immigrant education....

  6. Satellite Meteorology Education Resources Freely Available from COMET°

    Science.gov (United States)

    Abshire, W. E.; Dills, P. N.

    2011-12-01

    The COMET° Program (www.comet.ucar.edu) receives funding from NOAA NESDIS, EUMETSAT, and the Meteorological Service of Canada to support education and training efforts in satellite meteorology. These partnerships enable COMET to create educational materials of global interest on the application of products from geostationary and polar-orbiting remote sensing platforms. Recently, COMET's satellite education programs have focused on both current and next generation satellites and their relevance to operational forecasters and other communities. By partnering with experts from the Naval Research Laboratory, NOAA-NESDIS and its Cooperative Institutes, MSC, and other user communities, COMET stimulates greater utilization of satellite data and products. COMET also continues to broaden the scope of its training to include materials on the EUMETSAT Polar-orbiting System (EPS) and Meteosat geostationary satellites. EPS represents an important contribution to the Initial Joint Polar System between NOAA and EUMETSAT, while Meteosat Second Generation imaging capabilities provide an authentic proving ground for the next-generation GOES-R imager. This presentation provides an overview of COMET's recent satellite education efforts including courses and publications that focus on topics like multispectral RGB products, detecting atmospheric dust, and climate monitoring from satellites. Over 50 satellite-focused self-paced online materials are freely available via the Satellite Topic area of the MetEd Web site (www.meted.ucar.edu/topics/modules/satellite) and COMET's Environmental Satellite Resource Center (ESRC)(www.meted.ucar.edu/esrc). The ESRC, another important resource developed for use by the geosciences and education communities, is a searchable, database driven Web site that provides easy access to a wide range of useful information and training materials on Earth-observing satellites. Simple free online registration is required to access all training materials and the

  7. NNIC—neural network image compressor for satellite positioning system

    Science.gov (United States)

    Danchenko, Pavel; Lifshits, Feodor; Orion, Itzhak; Koren, Sion; Solomon, Alan D.; Mark, Shlomo

    2007-04-01

    We have developed an algorithm, based on novel techniques of data compression and neural networks for the optimal positioning of a satellite. The algorithm is described in detail, and examples of its application are given. The heart of this algorithm is the program NNIC—neural network image compressor. This program was developed for compression color and grayscale images with artificial neural networks (ANNs). NNIC applies three different methods for compression. Two of them are based on neural networks architectures—multilayer perceptron and kohonen network. The third is based on a widely used method of discrete cosine transform, the basis for the JPEG standard. The program also serves as a tool for determining numerical and visual quality parameters of compression and comparison between different methods. A number of advantages and disadvantages of the compression using ANNs were discovered in the course of the present research, some of them presented in this report. The thrust of the report is the discussion of ANNs implementation problems for modern platforms, such as a satellite positioning system that include intensive image flowing and processing.

  8. Educational Benefits From the AAU-cubesat Student Satellite Project

    DEFF Research Database (Denmark)

    Alminde, Lars

    2003-01-01

    In September 2001 Aalborg university started the AAU-cubesat project that reached it climax when the student built satellite was launched into space on the 30th of June 2003 on top of a former Russian ICBM. AAU-cubesat was among the first five satellites to be launched that are built within......-satellite designs will be given. In addition as the project has been carried through by students then the educational value will be addressed as well....

  9. Mexico's National Educational Videoconferencing Network.

    Science.gov (United States)

    Pisanty, Alejandro

    This paper begins with background on the National University of Mexico (UNAM) and its networks. Other distance education projects in Mexico are described, including projects of the Instituto Politecnico Nacional (IPN), the National Distance Education Program operated by the Secretary of Education, and the Instituto Tecnologico y de Estudios…

  10. A university-based distributed satellite mission control network for operating professional space missions

    Science.gov (United States)

    Kitts, Christopher; Rasay, Mike

    2016-03-01

    For more than a decade, Santa Clara University's Robotic Systems Laboratory has operated a unique, distributed, internet-based command and control network for providing professional satellite mission control services for a variety of government and industry space missions. The system has been developed and is operated by students who become critical members of the mission teams throughout the development, test, and on-orbit phases of these missions. The mission control system also supports research in satellite control technology and hands-on student aerospace education. This system serves as a benchmark for its comprehensive nature, its student-centric nature, its ability to support NASA and industry space missions, and its longevity in providing a consistent level of professional services. This paper highlights the unique features of this program, reviews the network's design and the supported spacecraft missions, and describes the critical programmatic features of the program that support the control of professional space missions.

  11. Hierarchical Supervisor and Agent Routing Algorithm in LEO/MEO Double-layered Optical Satellite Network

    Science.gov (United States)

    Li, Yongjun; Zhao, Shanghong

    2016-09-01

    A novel routing algorithm (Hierarchical Supervisor and Agent Routing Algorithm, HSARA) for LEO/MEO (low earth orbit/medium earth orbit) double-layered optical satellite network is brought forward. The so-called supervisor (MEO satellite) is designed for failure recovery and network management. LEO satellites are grouped according to the virtual managed field of MEO which is different from coverage area of MEO satellite in RF satellite network. In each LEO group, one LEO satellite which has maximal persistent link with its supervisor is called the agent. A LEO group is updated when this optical inter-orbit links between agent LEO satellite and the corresponding MEO satellite supervisor cuts off. In this way, computations of topology changes and LEO group updating can be decreased. Expense of routing is integration of delay and wavelength utilization. HSARA algorithm simulations are implemented and the results are as follows: average network delay of HSARA can reduce 21 ms and 31.2 ms compared with traditional multilayered satellite routing and single-layer LEO satellite respectively; LEO/MEO double-layered optical satellite network can cover polar region which cannot be covered by single-layered LEO satellite and throughput is 1% more than that of single-layered LEO satellite averagely. Therefore, exact global coverage can be achieved with this double-layered optical satellite network.

  12. A Time and Space-based Dynamic IP Routing in Broadband Satellite Networks

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The topology architecture, characteristics and routing technologies of broadband satellite networks are studied in this paper. The authors propose the routing scheme of satellite networks and design a time and space-based distributed routing algorithm whose complexity is O(1). Simulation results aiming at satellite mobility show that the new algorithm can determine the minimum propagation delay paths effectively.

  13. A Social Networks in Education

    Science.gov (United States)

    Klimova, Blanka; Poulova, Petra

    2015-01-01

    At present social networks are becoming important in all areas of human activities. They are simply part and parcel of everyday life. They are mostly used for advertising, but they have already found their way into education. The future potential of social networks is high as it can be seen from their statistics on a daily, monthly or yearly…

  14. Reconstructing regional climate networks from irregularly sampled satellite data

    Science.gov (United States)

    Wiedermann, Marc; Donner, Reik V.; Sykioti, Olga; Papadimitriou, Constantinos; Kurths, Jürgen

    2015-04-01

    With the increasing availability of remote sensing data Earth System Analysis has taken a great step forward. Satellite data with high resolution in time and space allow for an in-depth analysis of small-scale processes in the climate as well as ecosystems. This data type, however, also harbors crucial conceptual complications. First, depending on whether the satellite is orbiting on an ascending or descending path systematic biases are induced into the dataset and both measurements can not be evaluated simultaneously without an appropriate preprocessing. Second, remote sensing data are usually not produced with equidistant temporal sampling, but might contain huge gaps, due to cloud cover or maintenance work and irregular time steps, due to the orbiting time of the satellite. In this work, we utilize sea surface temperature (SST) data obtained from the SMOS satellite as part of ESA's Earth Explorer Mission to study small-scale regional interactions between different parts of the Mediterranean, Aegean and Black Sea. In a first step, we create homogeneous time series for each grid point by combining data from ascending and descending satellite paths by utilizing principal component and singular spectrum analysis. To address the issue of irregular temporal sampling we utilize a kernel weighted version of the linear cross-correlation function to compute lagged correlations between all pairs of grid points in the dataset. By setting a threshold to the thus obtained correlation matrix we obtain a binary matrix which can be interpreted as the adjacency matrix of a complex network. We then use tools from complex network theory to study regional interdependencies in the study area for different time lags of up to forty days. We find that the obtained networks represent well the observed average wind directions and speeds and display interaction structures between small regions in the Aegean Sea, which are in good agreement with earlier observations. The methods presented

  15. New dynamic routing algorithm based on MANET in LEO/MEO satellite network

    Institute of Scientific and Technical Information of China (English)

    LI Zhe; LI Dong-ni; WANG Guang-xing

    2006-01-01

    The features of low earth orbit/medium earth orbit (LEO/MEO) satellite networks routing algorithm based on inter-satellite link are analyzed and the similarities between satellite networks and mobile Ad Hoc network (MANET) are pointed out.The similar parts in MANET routing protocol are used in the satellite network for reference.A new dynamic routing algorithm based on MANET in LEO/MEO satellite networks,which fits for the LEO/MEO satellite communication system,is proposed.At the same time,the model of the algorithm is simulated and features are analyzed.It is shown that the algorithm has strong adaptability.It can give the network high autonomy,perfect function,low system overhead and great compatibility.

  16. Hardware demonstration of high-speed networks for satellite applications.

    Energy Technology Data Exchange (ETDEWEB)

    Donaldson, Jonathon W.; Lee, David S.

    2008-09-01

    This report documents the implementation results of a hardware demonstration utilizing the Serial RapidIO{trademark} and SpaceWire protocols that was funded by Sandia National Laboratories (SNL's) Laboratory Directed Research and Development (LDRD) office. This demonstration was one of the activities in the Modeling and Design of High-Speed Networks for Satellite Applications LDRD. This effort has demonstrated the transport of application layer packets across both RapidIO and SpaceWire networks to a common downlink destination using small topologies comprised of commercial-off-the-shelf and custom devices. The RapidFET and NEX-SRIO debug and verification tools were instrumental in the successful implementation of the RapidIO hardware demonstration. The SpaceWire hardware demonstration successfully demonstrated the transfer and routing of application data packets between multiple nodes and also was able reprogram remote nodes using configuration bitfiles transmitted over the network, a key feature proposed in node-based architectures (NBAs). Although a much larger network (at least 18 to 27 nodes) would be required to fully verify the design for use in a real-world application, this demonstration has shown that both RapidIO and SpaceWire are capable of routing application packets across a network to a common downlink node, illustrating their potential use in real-world NBAs.

  17. Convolutional neural network features based change detection in satellite images

    Science.gov (United States)

    Mohammed El Amin, Arabi; Liu, Qingjie; Wang, Yunhong

    2016-07-01

    With the popular use of high resolution remote sensing (HRRS) satellite images, a huge research efforts have been placed on change detection (CD) problem. An effective feature selection method can significantly boost the final result. While hand-designed features have proven difficulties to design features that effectively capture high and mid-level representations, the recent developments in machine learning (Deep Learning) omit this problem by learning hierarchical representation in an unsupervised manner directly from data without human intervention. In this letter, we propose approaching the change detection problem from a feature learning perspective. A novel deep Convolutional Neural Networks (CNN) features based HR satellite images change detection method is proposed. The main guideline is to produce a change detection map directly from two images using a pretrained CNN. This method can omit the limited performance of hand-crafted features. Firstly, CNN features are extracted through different convolutional layers. Then, a concatenation step is evaluated after an normalization step, resulting in a unique higher dimensional feature map. Finally, a change map was computed using pixel-wise Euclidean distance. Our method has been validated on real bitemporal HRRS satellite images according to qualitative and quantitative analyses. The results obtained confirm the interest of the proposed method.

  18. A study of multiple access schemes in satellite control network

    Science.gov (United States)

    Mo, Zijian; Wang, Zhonghai; Xiang, Xingyu; Wang, Gang; Chen, Genshe; Nguyen, Tien; Pham, Khanh; Blasch, Erik

    2016-05-01

    Satellite Control Networks (SCN) have provided launch control for space lift vehicles; tracking, telemetry and commanding (TTC) for on-orbit satellites; and, test support for space experiments since the 1960s. Currently, SCNs encounter a new challenge: how to maintain the high reliability of services when sharing the spectrum with emerging commercial services. To achieve this goal, the capability of multiple satellites reception is deserved as an update/modernization of SCN in the future. In this paper, we conducts an investigation of multiple access techniques in SCN scenario, e.g., frequency division multiple access (FDMA) and coded division multiple access (CDMA). First, we introduce two upgrade options of SCN based on FDMA and CDMA techniques. Correspondingly, we also provide their performance analysis, especially the system improvement in spectrum efficiency and interference mitigation. Finally, to determine the optimum upgrade option, this work uses CRISP, i.e., Cost, Risk, Installation, Supportability and Performance, as the baseline approach for a comprehensive trade study of these two options. Extensive numerical and simulation results are presented to illustrate the theoretical development.

  19. Regional climate network analysis from irregularly sampled satellite data

    Science.gov (United States)

    Wiedermann, Marc; Sykioti, Olga; Papadimitriou, Constantinos; Balasis, George; Kurths, Jürgen; Donner, Reik V.

    2016-04-01

    With the increasing availability of remote sensing data Earth System Analysis has taken a great step forward. This type of data, however, also harbors a variety of conceptual complications. First, depending on whether the satellite is orbiting on an ascending or descending path systematic biases are induced into the data, and both measurements cannot be evaluated simultaneously without an appropriate preprocessing. Second, remote sensing data are usually not produced with equidistant temporal sampling, but might contain huge gaps and irregular time steps. Third, the time period covered by the data is often too short to perform an appropriate seasonal detrending. Here, we propose a general framework to create homogeneous anomalized time series for a (multivariate) satellite data set by combining time series from ascending and descending satellite paths or even different missions using principal component and singular spectrum analysis. We then exemplarily apply our method to sea surface temperature data obtained from the SMOS satellite mission to study small-scale regional correlative patterns covering different parts of the Aegean Sea. To address the issue of irregular temporal sampling we utilize a kernel weighted version of the linear cross-correlation function to compute lagged correlations between all pairs of grid points in the data set. By binarizing the thus obtained matrices, we obtain a network representation of the system's similarity structure. Ultimately, we use tools from complex network theory to study regional interdependencies in the study area for different time lags of up to forty days. We find that the obtained networks represent well the observed average wind directions and speeds and display interaction structures between small regions in the Aegean Sea, which are in good agreement with earlier observations. In a second step, we extend the study area to the whole Mediterranean and Black Sea and investigate lagged interactions between these two

  20. A Multicast Routing Algorithm for Datagram Service in Delta LEO Satellite Constellation Networks

    Directory of Open Access Journals (Sweden)

    Yanpeng Ma

    2014-04-01

    Full Text Available Satellites can broadcast datagram over wide areas, therefore, the satellite network has congenital advantages to implement multicast service. LEO satellite has the property of efficient bandwidth usage, lower propagation delay and lower power consumption in the user terminals and satellites. Therefore, the constellation network composed by LEO satellites is an essential part of future satellite communication networks. In this paper, we propose a virtual center based multicast (VCMulticast routing algorithm for LEO satellite constellation network. The algorithm uses the geographic center information of group users to route multicast datagrams, with less memory, computer power and signaling overhead. We evaluate the delay and performance of our algorithm by means of simulations in the OPENET simulator. The results indicate that the delay of the proposed multicast method exceeds the minimum propagation by at most 29.1% on the average, which is a quite acceptable achievement, considering the resource overhead reduction that can be introduced by our proposal

  1. Satellite image eavesdropping: a multidisciplinary science education project

    Energy Technology Data Exchange (ETDEWEB)

    Friedt, Jean-Michel [Association Projet Aurore, UFR-ST La Bouloie, 16, route de Gray, 25030 Besancon Cedex (France)

    2005-11-01

    Amateur reception of satellite images gathers a wide number of concepts and technologies which makes it attractive as an educational tool. We here introduce the reception of images emitted from NOAA series low-altitude Earth-orbiting satellites. We tackle various issues including the identification and prediction of the pass time of visible satellites, the building of the radio-frequency receiver and antenna after modelling their radiation pattern, and then the demodulation of the resulting audio signal for finally displaying an image of the Earth as seen from space.

  2. Educational Benefits from the AAU-Cubesat Student Satellite Project

    DEFF Research Database (Denmark)

    Alminde, Lars

    2003-01-01

    In September 2001 Aalborg university started the AAU-cubesat project that reached it climax when the student built satellite was launched into space on the 30th of June 2003 on top of a former Russian ICBM. AAU-cubesat was among the first five satellites to be launched that are built within the c...... on pico-satellite designs will be given. In addition as the project has been carried through by students then the educational value will be addressed as well.......In September 2001 Aalborg university started the AAU-cubesat project that reached it climax when the student built satellite was launched into space on the 30th of June 2003 on top of a former Russian ICBM. AAU-cubesat was among the first five satellites to be launched that are built within...... the cubesat concept that prescribes a satellite with dimensions 10x10x10cm and mass one kilogram. These constraints clearly limits the possibilities for the satellite in terms of possible scientific missions, but on the other hand: by building satellites of this size a technology push is created...

  3. Applications of a Networked Array of Small Satellites for Planetary Observation

    NARCIS (Netherlands)

    Gunter, B.C.; Maessen, D.C.

    2010-01-01

    The goal of this study is to explore those applications which can best utilize a network of orbiting satellites working as a distributed computing array. The satellites are presumed to be low-cost mini- or micro-satellites orbiting Earth or some other celestial body (i.e., an asteroid, moon, etc.),

  4. Applications of a Networked Array of Small Satellites for Planetary Observation

    NARCIS (Netherlands)

    Gunter, B.C.; Maessen, D.C.

    2010-01-01

    The goal of this study is to explore those applications which can best utilize a network of orbiting satellites working as a distributed computing array. The satellites are presumed to be low-cost mini- or micro-satellites orbiting Earth or some other celestial body (i.e., an asteroid, moon, etc.),

  5. Program on application of communications satellites to educational development

    Science.gov (United States)

    Morgan, R. P.; Singh, J. P.

    1971-01-01

    Interdisciplinary research in needs analysis, communications technology studies, and systems synthesis is reported. Existing and planned educational telecommunications services are studied and library utilization of telecommunications is described. Preliminary estimates are presented of ranges of utilization of educational telecommunications services for 1975 and 1985; instructional and public television, computer-aided instruction, computing resources, and information resource sharing for various educational levels and purposes. Communications technology studies include transmission schemes for still-picture television, use of Gunn effect devices, and TV receiver front ends for direct satellite reception at 12 GHz. Two major studies in the systems synthesis project concern (1) organizational and administrative aspects of a large-scale instructional satellite system to be used with schools and (2) an analysis of future development of instructional television, with emphasis on the use of video tape recorders and cable television. A communications satellite system synthesis program developed for NASA is now operational on the university IBM 360-50 computer.

  6. TCP-ATCA: Improved Transmission Control Algorithm in Satellite Network

    Institute of Scientific and Technical Information of China (English)

    Liu Feng; Liu Hengna; Zhao Han

    2008-01-01

    An adaptive transmission control algorithm based on TCP (TCP-ATCA) is proposed to reduce the effects of long propagation de- lay and high link error rate of the satellite network on the performances. The flow control and the error recovery are differentiated by combined dynamic random early detection-explicit congestion notification (DRED-ECN) algorithm, and, moreover, the pertaining con- gestion control methods are used in TCP-ATCA to improve the throughput. By introducing the entire recovery algorithm, the unneces- sary congestion window decrease is reduced, and the throughput and fairness are improved. Simulation results show that, compared with TCP-Reno, TCP-ATCA provides a better throughput performance when the link capacity is higher (≥ 600 packet/s), and roughly the same when it is lower. At the same time, TCP-ATCA also increases fairness and reduces transmission delay.

  7. Economically sustainable public security and emergency network exploiting a broadband communications satellite

    OpenAIRE

    Lawal, Lasisi Salami

    2014-01-01

    The research contributes to work in Rapid Deployment of a National Public Security and Emergency Communications Network using Communication Satellite Broadband. Although studies in Public Security Communication networks have examined the use of communications satellite as an integral part of the Communication Infrastructure, there has not been an in-depth design analysis of an optimized regional broadband-based communication satellite in relation to the envisaged service coverage area, with l...

  8. Negative Attitudes, Network and Education

    DEFF Research Database (Denmark)

    Bennett, Patrick; la Cour, Lisbeth; Larsen, Birthe

    to an ambiguous impact. Empirically, we consider immigrants’ high school attendance. On the macro-level, we confirm a signficant negative correlation between negative attitudes towards immigrants and high school attendance and a positive impact of networking on high school attendance. On the individual level, we...... use Danish register data to find a signficant positive correlation between negative attitudes towards immigrants and high school attendance and find a positive impact of networking on high school attendance. In both the macro and the micro-econometric analysis we run the same regressions for natives......We consider the impact of negative attitudes against immigrants and immigration on educational choice in a search and wage bargaining model including networking. We consider two cases in terms of the importance of negative attitudes againts immigrants for high and low educated individuals and find...

  9. Capacity Model and Constraints Analysis for Integrated Remote Wireless Sensor and Satellite Network in Emergency Scenarios

    Directory of Open Access Journals (Sweden)

    Wei Zhang

    2015-11-01

    Full Text Available This article investigates the capacity problem of an integrated remote wireless sensor and satellite network (IWSSN in emergency scenarios. We formulate a general model to evaluate the remote sensor and satellite network capacity. Compared to most existing works for ground networks, the proposed model is time varying and space oriented. To capture the characteristics of a practical network, we sift through major capacity-impacting constraints and analyze the influence of these constraints. Specifically, we combine the geometric satellite orbit model and satellite tool kit (STK engineering software to quantify the trends of the capacity constraints. Our objective in analyzing these trends is to provide insights and design guidelines for optimizing the integrated remote wireless sensor and satellite network schedules. Simulation results validate the theoretical analysis of capacity trends and show the optimization opportunities of the IWSSN.

  10. Enhancing End-to-End Performance of Information Services Over Ka-Band Global Satellite Networks

    Science.gov (United States)

    Bhasin, Kul B.; Glover, Daniel R.; Ivancic, William D.; vonDeak, Thomas C.

    1997-01-01

    The Internet has been growing at a rapid rate as the key medium to provide information services such as e-mail, WWW and multimedia etc., however its global reach is limited. Ka-band communication satellite networks are being developed to increase the accessibility of information services via the Internet at global scale. There is need to assess satellite networks in their ability to provide these services and interconnect seamlessly with existing and proposed terrestrial telecommunication networks. In this paper the significant issues and requirements in providing end-to-end high performance for the delivery of information services over satellite networks based on various layers in the OSI reference model are identified. Key experiments have been performed to evaluate the performance of digital video and Internet over satellite-like testbeds. The results of the early developments in ATM and TCP protocols over satellite networks are summarized.

  11. Energy-Efficient Optimal Power Allocation in Integrated Wireless Sensor and Cognitive Satellite Terrestrial Networks.

    Science.gov (United States)

    Shi, Shengchao; Li, Guangxia; An, Kang; Gao, Bin; Zheng, Gan

    2017-09-04

    This paper proposes novel satellite-based wireless sensor networks (WSNs), which integrate the WSN with the cognitive satellite terrestrial network. Having the ability to provide seamless network access and alleviate the spectrum scarcity, cognitive satellite terrestrial networks are considered as a promising candidate for future wireless networks with emerging requirements of ubiquitous broadband applications and increasing demand for spectral resources. With the emerging environmental and energy cost concerns in communication systems, explicit concerns on energy efficient resource allocation in satellite networks have also recently received considerable attention. In this regard, this paper proposes energy-efficient optimal power allocation schemes in the cognitive satellite terrestrial networks for non-real-time and real-time applications, respectively, which maximize the energy efficiency (EE) of the cognitive satellite user while guaranteeing the interference at the primary terrestrial user below an acceptable level. Specifically, average interference power (AIP) constraint is employed to protect the communication quality of the primary terrestrial user while average transmit power (ATP) or peak transmit power (PTP) constraint is adopted to regulate the transmit power of the satellite user. Since the energy-efficient power allocation optimization problem belongs to the nonlinear concave fractional programming problem, we solve it by combining Dinkelbach's method with Lagrange duality method. Simulation results demonstrate that the fading severity of the terrestrial interference link is favorable to the satellite user who can achieve EE gain under the ATP constraint comparing to the PTP constraint.

  12. Neural Network Based Lna Design for Mobile Satellite Receiver

    Directory of Open Access Journals (Sweden)

    Abhijeet Upadhya

    2014-08-01

    Full Text Available Paper presents a Neural Network Modelling approach to microwave LNA design. To acknowledge the specifications of the amplifier, Mobile Satellite Systems are analyzed. Scattering parameters of the LNA in the frequency range 0.5 to 18 GHz are calculated using a Multilayer Perceptron Artificial Neural Network model and corresponding smith charts and polar charts are plotted as output to the model. From these plots, the microwave scattering parameter description of the LNA are obtained. Model is efficiently trained using Agilent ATF 331M4 InGaAs/InP Low Noise pHEMT amplifier datasheet and the neural model’s output seem to follow the various device characteristic curves with high regression. Next, Maximum Allowable Gain and Noise figure of the device are modelled and plotted for the same frequency range. Finally, the optimized model is utilized as an interpolator and the resolution of the amplifying capability with noise characteristics are obtained for the L Band of MSS operation.

  13. Romanian Educational Seismic Network Project

    Science.gov (United States)

    Tataru, Dragos; Ionescu, Constantin; Zaharia, Bogdan; Grecu, Bogdan; Tibu, Speranta; Popa, Mihaela; Borleanu, Felix; Toma, Dragos; Brisan, Nicoleta; Georgescu, Emil-Sever; Dobre, Daniela; Dragomir, Claudiu-Sorin

    2013-04-01

    Romania is one of the most active seismic countries in Europe, with more than 500 earthquakes occurring every year. The seismic hazard of Romania is relatively high and thus understanding the earthquake phenomena and their effects at the earth surface represents an important step toward the education of population in earthquake affected regions of the country and aims to raise the awareness about the earthquake risk and possible mitigation actions. In this direction, the first national educational project in the field of seismology has recently started in Romania: the ROmanian EDUcational SEISmic NETwork (ROEDUSEIS-NET) project. It involves four partners: the National Institute for Earth Physics as coordinator, the National Institute for Research and Development in Construction, Urban Planning and Sustainable Spatial Development " URBAN - INCERC" Bucharest, the Babeş-Bolyai University (Faculty of Environmental Sciences and Engineering) and the software firm "BETA Software". The project has many educational, scientific and social goals. The main educational objectives are: training students and teachers in the analysis and interpretation of seismological data, preparing of several comprehensive educational materials, designing and testing didactic activities using informatics and web-oriented tools. The scientific objective is to introduce into schools the use of advanced instruments and experimental methods that are usually restricted to research laboratories, with the main product being the creation of an earthquake waveform archive. Thus a large amount of such data will be used by students and teachers for educational purposes. For the social objectives, the project represents an effective instrument for informing and creating an awareness of the seismic risk, for experimentation into the efficacy of scientific communication, and for an increase in the direct involvement of schools and the general public. A network of nine seismic stations with SEP seismometers

  14. Network Performance Evaluation of Abis Interface over DVB-S2 in the GSM over Satellite Network

    Directory of Open Access Journals (Sweden)

    S. B. Musabekov

    2010-01-01

    Full Text Available This paper deals with establishing a GSM link over Satellite. Abis interface, which is defined between Base Transceiver Station (BTS and Base Station Controller (BSC, in a GSM network is considered here to be routed over the Satellite. The satellite link enables a quick and cost-effective GSM link in meagerly populated areas. A different scenario comparison was done to understand the impact of Satellite environment on network availability comparing to terrestrial scenario. We have implemented an Abis interface over DVB S2 in NS2 and evaluated the performance over the high delay and loss satellite channel. Network performance was evaluated with respect to Satellite channel delay and DVB S2 encapsulation efficiency under different amount of user traffic and compared with the terrestrial scenario. The results clearly showed an increased amount of SDCCH and TCH channels required in the case of satellite scenario for the same amount of traffic in comparison to conventional terrestrial scenario. We have optimized the parameters based on the simulation results. Link budget estimation considering DVB-S2 platform was done to find satellite bandwidth and cost requirements for different network setups.

  15. Study on networking issues of medium earth orbit satellite communications systems

    Science.gov (United States)

    Araki, Noriyuki; Shinonaga, Hideyuki; Ito, Yasuhiko

    1993-01-01

    Two networking issues of communications systems with medium earth orbit (MEO) satellites, namely network architectures and location determination and registration methods for hand-held terminals, are investigated in this paper. For network architecture, five candidate architectures are considered and evaluated in terms of signaling traffic. For location determination and registration, two methods are discussed and evaluated.

  16. Beam forming networks for mm-wave satellite communications

    Science.gov (United States)

    Sharon, T. E.

    1983-01-01

    Technology features of a beam forming network (BFN) employing ferrite devices to provide multiple beam antenna pattern control for satellites used in telecommunications are described. The BFN produces the phase and amplitude distribution for each horn in an antenna array, with the number of horns in the array being equal to the number of outputs in the BFN. One configuration involves microwave switches and permits illumination of a single feed horn at a time using ferrite latching circulators that function by reversing the circulation direction. A more flexible version, yielding a variable amplitude distribution across the feed horn array to accommodate changing traffic patterns or serving a TDMA system, includes the capability of forming nulls in the system with a variable phase shifter in the input ports. The antenna scan angles in phased arrays can be limited to 8 deg from center. Acceptable insertion losses have been demonstrated in BFN with hundreds of ports and switching rates as high as 10 kHz.

  17. Beam forming networks for mm-wave satellite communications

    Science.gov (United States)

    Sharon, T. E.

    1983-08-01

    Technology features of a beam forming network (BFN) employing ferrite devices to provide multiple beam antenna pattern control for satellites used in telecommunications are described. The BFN produces the phase and amplitude distribution for each horn in an antenna array, with the number of horns in the array being equal to the number of outputs in the BFN. One configuration involves microwave switches and permits illumination of a single feed horn at a time using ferrite latching circulators that function by reversing the circulation direction. A more flexible version, yielding a variable amplitude distribution across the feed horn array to accommodate changing traffic patterns or serving a TDMA system, includes the capability of forming nulls in the system with a variable phase shifter in the input ports. The antenna scan angles in phased arrays can be limited to 8 deg from center. Acceptable insertion losses have been demonstrated in BFN with hundreds of ports and switching rates as high as 10 kHz.

  18. Strategic Knowledge Networks for Global Education

    Science.gov (United States)

    Peterson, J. Fiona

    2009-01-01

    The inherent opportunities for communication, collaboration and experiential learning in an online and global network create the impetus for the new network paradigm in higher education. A strategic knowledge network in education was designed and developed to build "Mode 2" knowledge capabilities; create new knowledge for innovative application;…

  19. Network design for telemedicine--e-health using satellite technology.

    Science.gov (United States)

    Graschew, Georgi; Roelofs, Theo A; Rakowsky, Stefan; Schlag, Peter M

    2008-01-01

    Over the last decade various international Information and Communications Technology networks have been created for a global access to high-level medical care. OP 2000 has designed and validated the high-end interactive video communication system WinVicos especially for telemedical applications, training of the physician in a distributed environment, teleconsultation and second opinion. WinVicos is operated on a workstation (WoTeSa) using standard hardware components and offers a superior image quality at a moderate transmission bandwidth of up to 2 Mbps. WoTeSa / WinVicos have been applied for IP-based communication in different satellite-based telemedical networks. In the DELTASS-project a disaster scenario was analysed and an appropriate telecommunication system for effective rescue measures for the victims was set up and evaluated. In the MEDASHIP project an integrated system for telemedical services (teleconsultation, teleelectro-cardiography, telesonography) on board of cruise ships and ferries has been set up. EMISPHER offers an equal access for most of the countries of the Euro-Mediterranean area to on-line services for health care in the required quality of service. E-learning applications, real-time telemedicine and shared management of medical assistance have been realized. The innovative developments in ICT with the aim of realizing a ubiquitous access to medical resources for everyone at any time and anywhere (u-Health) bear the risk of creating and amplifying a digital divide in the world. Therefore we have analyzed how the objective needs of the heterogeneous partners can be joined with the result that there is a need for real integration of the various platforms and services. A virtual combination of applications serves as the basic idea for the Virtual Hospital. The development of virtual hospitals and digital medicine helps to bridge the digital divide between different regions of the world and enables equal access to high-level medical care. Pre

  20. A Novel Onboard-gateway-based Mechanism to Improve TCP Performance in Aeronautical Satellite Networks

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The IP-based networks on aircraft serve to support Internet services via satellites. However, in aeronautical satellite hybrid networks, the TCP protocol performance often deteriorates due to improper decreases and slow recovery of the congestion window. This paper proposes a window size determination and notification mechanism, onboard-gateway-based mechanism (OGBM), which is based on the onboard gateway in the networks on aircraft. A cross-layer approach is adopted by the onboard gateway to obtain the satellite link bandwidth information. And then, by the gateway, through changing the receiver's advertised window field in ACK packets, TCP sources are notified of the window size of each TCP source calculated on the ground of bandwidth delay product and flow numbers. The mechanism is able to avoid improper changes of TCP window and serve multiple users. Simulation results show that the mechanism with the fairness index close to 1 improves TCP performance in aeronautical satellite networks.

  1. Potentials and Limitations of CDMA Networks for Combined Inter-Satellite Communication and Relative Navigation

    NARCIS (Netherlands)

    Sun, R.; Guo, J.; Gill, E.K.A.; Maessen, D.C.

    2012-01-01

    Precision formation flying missions require formation acquisition and maintenance through the interactions among spacecraft by the inter-satellite communication and relative navigation. This paper analyses the dedicated system constraints of the network architecture for precision formation flying mi

  2. Innovative Large Scale Wireless Sensor Network Architecture Using Satellites and High-Altitude Platforms

    Directory of Open Access Journals (Sweden)

    Yasser Albagory

    2014-03-01

    Full Text Available Wireless sensor network has many applications and very active research area. The coverage span of this network is very important parameter where wide coverage area is a challenge. This paper proposes an architecture for large-scale wireless sensor network (LSWSN based on satellites and the High-Altitude Platforms (HAP where the sensor nodes are located on the ground and a wide coverage sink station may be in the form of a satellite or a network of HAPs. A scenario is described for multilayer LSWSN and a study for the system requirements has been established showing the number of Satellites, HAPs and coverage per each sink according to the elevation angle requirements. The Satellite-HAP-Sensor multilayer LSWSN architecture has the feasibility for effective energy and earth coverage and is optimum for covering largely sparse regions.

  3. Modeling management of research and education networks

    NARCIS (Netherlands)

    Galagan, D.V.

    2004-01-01

    Computer networks and their services have become an essential part of research and education. Nowadays every modern R&E institution must have a computer network and provide network services to its students and staff. In addition to its internal computer network, every R&E institution must have a con

  4. Technological Developments in Networking, Education and Automation

    CERN Document Server

    Elleithy, Khaled; Iskander, Magued; Kapila, Vikram; Karim, Mohammad A; Mahmood, Ausif

    2010-01-01

    "Technological Developments in Networking, Education and Automation" includes a set of rigorously reviewed world-class manuscripts addressing and detailing state-of-the-art research projects in the following areas: Computer Networks: Access Technologies, Medium Access Control, Network architectures and Equipment, Optical Networks and Switching, Telecommunication Technology, and Ultra Wideband Communications. Engineering Education and Online Learning: including development of courses and systems for engineering, technical and liberal studies programs; online laboratories; intelligent

  5. Cooperative network clustering and task allocation for heterogeneous small satellite network

    Science.gov (United States)

    Qin, Jing

    The research of small satellite has emerged as a hot topic in recent years because of its economical prospects and convenience in launching and design. Due to the size and energy constraints of small satellites, forming a small satellite network(SSN) in which all the satellites cooperate with each other to finish tasks is an efficient and effective way to utilize them. In this dissertation, I designed and evaluated a weight based dominating set clustering algorithm, which efficiently organizes the satellites into stable clusters. The traditional clustering algorithms of large monolithic satellite networks, such as formation flying and satellite swarm, are often limited on automatic formation of clusters. Therefore, a novel Distributed Weight based Dominating Set(DWDS) clustering algorithm is designed to address the clustering problems in the stochastically deployed SSNs. Considering the unique features of small satellites, this algorithm is able to form the clusters efficiently and stably. In this algorithm, satellites are separated into different groups according to their spatial characteristics. A minimum dominating set is chosen as the candidate cluster head set based on their weights, which is a weighted combination of residual energy and connection degree. Then the cluster heads admit new neighbors that accept their invitations into the cluster, until the maximum cluster size is reached. Evaluated by the simulation results, in a SSN with 200 to 800 nodes, the algorithm is able to efficiently cluster more than 90% of nodes in 3 seconds. The Deadline Based Resource Balancing (DBRB) task allocation algorithm is designed for efficient task allocations in heterogeneous LEO small satellite networks. In the task allocation process, the dispatcher needs to consider the deadlines of the tasks as well as the residue energy of different resources for best energy utilization. We assume the tasks adopt a Map-Reduce framework, in which a task can consist of multiple

  6. Satellites vs. fiber optics based networks and services - Road map to strategic planning

    Science.gov (United States)

    Marandi, James H. R.

    An overview of a generic telecommunications network and its components is presented, and the current developments in satellite and fiber optics technologies are discussed with an eye on the trends in industry. A baseline model is proposed, and a cost comparison of fiber- vs satellite-based networks is made. A step-by-step 'road map' to the successful strategic planning of telecommunications services and facilities is presented. This road map provides for optimization of the current and future networks and services through effective utilization of both satellites and fiber optics. The road map is then applied to different segments of the telecommunications industry and market place, to show its effectiveness for the strategic planning of executives of three types: (1) those heading telecommunications manufacturing concerns, (2) those leading communication service companies, and (3) managers of telecommunication/MIS departments of major corporations. Future networking issues, such as developments in integrated-services digital network standards and technologies, are addressed.

  7. Performance tests of a satellite-based asymmetric communication network for the 'hyper hospital'.

    Science.gov (United States)

    Yamaguchi, T

    1997-01-01

    The Hyper Hospital is a prototype networked telemedicine system which uses virtual reality. We measured the performance of a novel multimedia network based on satellite communications. The network was a hybrid system consisting of a satellite channel in one direction and a terrestrial channel in the other. Each user was equipped with a standard satellite communication receiver and a telephone connection. Requests from the users were sent by modern and telephone line and responses were received by satellite. The user requests were initiated by clicking buttons on a World Wide Web browser screen. The transmission rates of satellite and normal telephone-line communications were compared for standardized text data. Satellite communication was three to five times faster. The transmission rate was also measured for standardized graphical data (GIF format). With a file size of about 400 kByte, satellite-mediated communication was 10 times faster than telephone lines. The effect of simultaneous access on performance was also explored. For simultaneous access of nine users to a single graphics file, 78% of the transmission speed was obtained in comparison with that of a single user. The satellite-based system showed excellent high-speed communication performance, particularly for multimedia data.

  8. Open Educational Resources in Learning Networks

    NARCIS (Netherlands)

    Sloep, Peter

    2009-01-01

    Sloep, P. B. (2009). Open Educational Resources in Learning Networks. Keynote presentation at the 23rd ICDE World Conference on Open Learning and Distance Education 2009. June, 5-7, 2009, Maastricht, The Netherlands.

  9. Research-related intercultural higher education in satellite geodesy

    Science.gov (United States)

    Mayer, M.; Heck, B.; Krueger, C. P.

    2009-04-01

    In order to improve the education of young researchers (master degree, PhD, PostDocs) a cooperation between the Department of Geomatics (DGEOM), Federal University of Paraná (UFPR), Curitiba (Brazil) and the Geodetic Institute (GIK), University Karlsruhe (TH), Karlsruhe (Germany) was established which now exists since more than five years. The joint venture is actually called "PROBRAL: Precise positioning and height determination by means of GPS: Modeling of errors and transformation into physical heights" and focuses on research and education within the field of satellite geodesy. PROBRAL is funded by the Brazilian academic exchange service CAPES and the German academic exchange service DAAD. The geodetic aim of the research project is to validate and improve the quality of 3d positions derived from observations related to satellite navigation systems like GPS. In order to fulfill this ambitious goal sustainably, research has to be carried out in close cooperation. At the same time, e.g. to guarantee continuous success, a coordinated education has to be ensured. Besides technical education aspects key competences (e.g. language, capacity for teamwork, project management skills) are trained. Within the presentation the lessons which were learned from this project are discussed in detail.

  10. Adaptive Distributed Load Balancing Routing Mechanism for LEO Satellite IP Networks

    Directory of Open Access Journals (Sweden)

    Xiao Ma

    2014-04-01

    Full Text Available LEO (Low Earth Orbit satellite constellation is an ideal scheme for the next generation wideband internet. The constellation is formed as a mesh-like network with inter satellite links (ISLs which are equipped between the neighbor satellites for transmitting directly. As to the future wideband IP services, an efficient routing mechanism will play an important role in improving the performance and balancing the network traffic. An Adaptive Distributed Load Balancing Routing Mechanism (ADLB is proposed in this paper to address the above-mentioned issues. This mechanism makes well-performed routing decision based on the current and historical status of each ISLs in each satellite node. With collecting historical information from network initiated, a proper mechanism is contained in ADLB for making required computing power and storage space in a reasonable range. The performance of ADLB is verified via a series of simulations which demonstrate that the scheme can provide better throughput and lower packet drop rate.

  11. Achieving QoS for TCP Traffic in Satellite Networks with Differentiated Services

    Science.gov (United States)

    Durresi, Arjan; Kota, Sastri; Goyal, Mukul; Jain, Raj; Bharani, Venkata

    2001-01-01

    Satellite networks play an indispensable role in providing global Internet access and electronic connectivity. To achieve such a global communications, provisioning of quality of service (QoS) within the advanced satellite systems is the main requirement. One of the key mechanisms of implementing the quality of service is traffic management. Traffic management becomes a crucial factor in the case of satellite network because of the limited availability of their resources. Currently, Internet Protocol (IP) only has minimal traffic management capabilities and provides best effort services. In this paper, we presented a broadband satellite network QoS model and simulated performance results. In particular, we discussed the TCP flow aggregates performance for their good behavior in the presence of competing UDP flow aggregates in the same assured forwarding. We identified several factors that affect the performance in the mixed environments and quantified their effects using a full factorial design of experiment methodology.

  12. Evolution of the NOAA National Weather Service Satellite Broadcast Network (SBN) to Europe's DVB-S satellite communications technology standard

    Science.gov (United States)

    Cragg, Phil; Brockman, William E.

    2006-08-01

    The National Oceanic and Atmospheric Administration's (NOAA) National Weather Service (NWS) uses a commercial Satellite Broadcast Network (SBN) to distribute weather data to the NWS AWIPS workstations and National Centers and to NWS Family of Service Users. Advances in science and technology from NOAA's observing systems, such as remote sensing satellites and NEXRAD radars, and advances in Numeric Weather Prediction have greatly increased the volume of data to be transmitted via the SBN. The NOAA-NWS SBN Evolution Program did a trade study resulting in the selection of Europe's DVB-S communication protocol as the basis for enabling a significant increase in the SBN capacity. The Digital Video Broadcast (DVB) group, started to develop digital TV for Europe through satellite broadcasting, has become the current standard for defining technology for satellite broadcasting of digital data for much of the world. NOAA-NWS implemented the DVB-S with inexpensive, Commercial Off The Shelf receiving equipment. The modernized NOAA-NWS SBN meets current performance goals and provides the basis for continued future expansion with no increase in current communication costs. This paper discusses aspects of the NOAA-NWS decision and the migration to the DVB-S standard for its commercial satellite broadcasts of observations and Numerical Weather Prediction data.

  13. An Evaluation Network for Educational Change.

    Science.gov (United States)

    Marchesi, Alvaro; Martin, Elena; Martinez Arias, Rosario; Tiana, Alejandro; Moreno, Amparo

    2003-01-01

    Describes the experience of an evaluation network being put into practice in Spain to encourage educational change. Outlines the most relevant conditions needed for educational change and develops the description of a school evaluation network that includes all the previously described conditions. (SLD)

  14. Networks and Collaboration in Spanish Education Policy

    Science.gov (United States)

    Azorín, Cecilia M.; Muijs, Daniel

    2017-01-01

    Background: Networks play an important role in today's societies. As a consequence, changes are apparent in the political, economic, cultural, educational and social agendas. Purpose: The main goal of this article is to map the situation of school networks in Spain. The research questions are focused on what forms collaboration and networking take…

  15. Bayesian networks in educational assessment

    CERN Document Server

    Almond, Russell G; Steinberg, Linda S; Yan, Duanli; Williamson, David M

    2015-01-01

    Bayesian inference networks, a synthesis of statistics and expert systems, have advanced reasoning under uncertainty in medicine, business, and social sciences. This innovative volume is the first comprehensive treatment exploring how they can be applied to design and analyze innovative educational assessments. Part I develops Bayes nets’ foundations in assessment, statistics, and graph theory, and works through the real-time updating algorithm. Part II addresses parametric forms for use with assessment, model-checking techniques, and estimation with the EM algorithm and Markov chain Monte Carlo (MCMC). A unique feature is the volume’s grounding in Evidence-Centered Design (ECD) framework for assessment design. This “design forward” approach enables designers to take full advantage of Bayes nets’ modularity and ability to model complex evidentiary relationships that arise from performance in interactive, technology-rich assessments such as simulations. Part III describes ECD, situates Bayes nets as ...

  16. UMR: A utility-maximizing routing algorithm for delay-sensitive service in LEO satellite networks

    Directory of Open Access Journals (Sweden)

    Lu Yong

    2015-04-01

    Full Text Available This paper develops a routing algorithm for delay-sensitive packet transmission in a low earth orbit multi-hop satellite network consists of micro-satellites. The micro-satellite low earth orbit (MS-LEO network endures unstable link connection and frequent link congestion due to the uneven user distribution and the link capacity variations. The proposed routing algorithm, referred to as the utility maximizing routing (UMR algorithm, improve the network utility of the MS-LEO network for carrying flows with strict end-to-end delay bound requirement. In UMR, first, a link state parameter is defined to capture the link reliability on continuing to keep the end-to-end delay into constraint; then, on the basis of this parameter, a routing metric is formulated and a routing scheme is designed for balancing the reliability in delay bound guarantee among paths and building a path maximizing the network utility expectation. While the UMR algorithm has many advantages, it may result in a higher blocking rate of new calls. This phenomenon is discussed and a weight factor is introduced into UMR to provide a flexible performance option for network operator. A set of simulations are conducted to verify the good performance of UMR, in terms of balancing the traffic distribution on inter-satellite links, reducing the flow interruption rate, and improving the network utility.

  17. Design Issues for Traffic Management for the ATM UBR + Service for TCP Over Satellite Networks

    Science.gov (United States)

    Jain, Raj

    1999-01-01

    This project was a comprehensive research program for developing techniques for improving the performance of Internet protocols over Asynchronous Transfer Mode (ATM) based satellite networks. Among the service categories provided by ATM networks, the most commonly used category for data traffic is the unspecified bit rate (UBR) service. UBR allows sources to send data into the network without any feedback control. The project resulted in the numerous ATM Forum contributions and papers.

  18. A Model for the Handover Traffic and Channel Occupancy Time in LEO Satellite Networks

    Institute of Scientific and Technical Information of China (English)

    WangJingyu; YaoYongyang

    1995-01-01

    This paper presents a method to determine the parameters of the traffic model for the LEO satellite networks-the handover traffic and the mean channel occupancy time.The main idea is that the handover traffic is mainly due to the movement of the satellites and the velocity of the mobile terminals and earth rotation is ignored.The performance level can be calculated accord-ing to different handover queuing model.

  19. A Neural Network MLSE Receiver Based on Natural Gradient Descent: Application to Satellite Communications

    Directory of Open Access Journals (Sweden)

    Ibnkahla Mohamed

    2004-01-01

    Full Text Available The paper proposes a maximum likelihood sequence estimator (MLSE receiver for satellite communications. The satellite channel model is composed of a nonlinear traveling wave tube (TWT amplifier followed by a multipath propagation channel. The receiver is composed of a neural network channel estimator (NNCE and a Viterbi detector. The natural gradient (NG descent is used for training. Computer simulations show that the performance of our receiver is close to the ideal MLSE receiver in which the channel is perfectly known.

  20. Combined Geometric and Neural Network Approach to Generic Fault Diagnosis in Satellite Actuators and Sensors

    OpenAIRE

    Baldi, P.; Blanke, Mogens; P. Castaldi; Mimmo, N.; S. Simani

    2016-01-01

    This paper presents a novel scheme for diagnosis of faults affecting the sensors measuring the satellite attitude, body angular velocity and flywheel spin rates as well as defects related to the control torques provided by satellite reaction wheels. A nonlinear geometric design is used to avoid that aerodynamic disturbance torques have unwanted influence on the residuals exploited for fault detection and isolation. Radial basis function neural networks are used to obtain fault estimation filt...

  1. Facebook, Social Networking, and Business Education

    Science.gov (United States)

    Taylor, Steven A.; Mulligan, Jamie R.; Ishida, Chiharu

    2012-01-01

    Brown (2012) asserts that faculty perceptions of Web 2.0 for teaching will influence its adoption. For example, social media's influence on educational delivery is growing (Hrastinski and Dennon 2012). Zulu et al. (2011) note that business educators are only beginning to understand social networking related to education. We report an exploratory…

  2. A DISTRIBUTED QOS ROUTING BASED ON ANT ALGORITHM FOR LEO SATELLITE NETWORK

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Low Earth Orbit (LEO) satellites provide short round-trip delays and are becoming increasingly important. One of the challenges in LEO satellite networks is the development of specialized and efficient routing algorithms. To satisfy the QoS requirements of multimedia applications, satellite routing protocols should consider handovers and minimize their effect on the active connections. A distributed QoS routing scheme based on heuristic ant algorithm is proposed for satisfying delay bound and avoiding link congestion. Simulation results show that the call blocking probabilities of this algorithm are less than that of Shortest Path First (SPF) with different delay bound.

  3. Combined Geometric and Neural Network Approach to Generic Fault Diagnosis in Satellite Actuators and Sensors

    DEFF Research Database (Denmark)

    Baldi, P.; Blanke, Mogens; Castaldi, P.;

    2016-01-01

    This paper presents a novel scheme for diagnosis of faults affecting the sensors measuring the satellite attitude, body angular velocity and flywheel spin rates as well as defects related to the control torques provided by satellite reaction wheels. A nonlinear geometric design is used to avoid...... that aerodynamic disturbance torques have unwanted influence on the residuals exploited for fault detection and isolation. Radial basis function neural networks are used to obtain fault estimation filters that do not need a priori information about the fault internal models. Simulation results are based...... on a detailed nonlinear satellite model with embedded disturbance description. The results document the efficacy of the proposed diagnosis scheme....

  4. A COMBINED ADMISSION CONTROL ALGORITHM WITH DA PROTOCOL FOR SATELLITE ATM NETWORKS

    Institute of Scientific and Technical Information of China (English)

    Lu Rong; Cao Zhigang

    2006-01-01

    Admission control is an important strategy for Quality of Service (QoS) provisioning in Asynchronous Transfer Mode (ATM) networks. Based on a control-theory model of resources on-Demand Allocation (DA) protocol, the paper studies the effect of the protocol on the statistical characteristics of network traffic,and proposes a combined connection admission control algorithm with the DA protocol to achieve full utilization of link resources in satellite communication systems. The proposed algorithm is based on the cross-layer-design approach. Theoretical analysis and system simulation results show that the proposed algorithm can admit more connections within certain admission thresholds than one that does not take into account the DA protocol. Thus, the proposed algorithm can increase admission ratio of traffic sources for satellite ATM networks and improve satellite link utilization.

  5. Dynamic communications for small satellites using disruption tolerant network concepts

    NARCIS (Netherlands)

    Giuditta, N.; Gill, E.K.A.; Fernández, B.; Isaac, D.

    2009-01-01

    New network technologies are providing interconnectivity in areas previously unheard of. One of these novel technologies, named Disruption Tolerant Networking (DTN), shows promise for the space industry. In order to study its suitability for University projects, a model of a University space mission

  6. Chinese Surveying and Control Network for Earth-Orbit Satellites and Deep Space Detection

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The relationship between the surveying and control network(CSN) for earth-orbit satellite and spatial geodesy, and the relationship between the CSN for deep space celestial bodies and detectors, and deep space detection are briefly summarized, and so are the basic technical needs of the deep space surveying and control network(DSN). Then, the techniques, the constituents and the distributing of Chinese satellite CSN (CSCSN) and other radio observing establishments in China are introduced. Lastly, with the primary CSCSN and other observing establishments, some projects for China to rebuild a more perfect CSCSN, and to establish a DSN are analyzed and stated.

  7. Space Network IP Services (SNIS): An Architecture for Supporting Low Earth Orbiting IP Satellite Missions

    Science.gov (United States)

    Israel, David J.

    2005-01-01

    The NASA Space Network (SN) supports a variety of missions using the Tracking and Data Relay Satellite System (TDRSS), which includes ground stations in White Sands, New Mexico and Guam. A Space Network IP Services (SNIS) architecture is being developed to support future users with requirements for end-to-end Internet Protocol (IP) communications. This architecture will support all IP protocols, including Mobile IP, over TDRSS Single Access, Multiple Access, and Demand Access Radio Frequency (RF) links. This paper will describe this architecture and how it can enable Low Earth Orbiting IP satellite missions.

  8. Performance Analysis of Integrated Wireless Sensor and Multibeam Satellite Networks Under Terrestrial Interference

    Directory of Open Access Journals (Sweden)

    Hongjun Li

    2016-10-01

    Full Text Available This paper investigates the performance of integrated wireless sensor and multibeam satellite networks (IWSMSNs under terrestrial interference. The IWSMSNs constitute sensor nodes (SNs, satellite sinks (SSs, multibeam satellite and remote monitoring hosts (RMHs. The multibeam satellite covers multiple beams and multiple SSs in each beam. The SSs can be directly used as SNs to transmit sensing data to RMHs via the satellite, and they can also be used to collect the sensing data from other SNs to transmit to the RMHs. We propose the hybrid one-dimensional (1D and 2D beam models including the equivalent intra-beam interference factor β from terrestrial communication networks (TCNs and the equivalent inter-beam interference factor α from adjacent beams. The terrestrial interference is possibly due to the signals from the TCNs or the signals of sinks being transmitted to other satellite networks. The closed-form approximations of capacity per beam are derived for the return link of IWSMSNs under terrestrial interference by using the Haar approximations where the IWSMSNs experience the Rician fading channel. The optimal joint decoding capacity can be considered as the upper bound where all of the SSs’ signals can be jointly decoded by a super-receiver on board the multibeam satellite or a gateway station that knows all of the code books. While the linear minimum mean square error (MMSE capacity is where all of the signals of SSs are decoded singularly by a multibeam satellite or a gateway station. The simulations show that the optimal capacities are obviously higher than the MMSE capacities under the same conditions, while the capacities are lowered by Rician fading and converge as the Rician factor increases. α and β jointly affect the performance of hybrid 1D and 2D beam models, and the number of SSs also contributes different effects on the optimal capacity and MMSE capacity of the IWSMSNs.

  9. Performance Analysis of Integrated Wireless Sensor and Multibeam Satellite Networks Under Terrestrial Interference.

    Science.gov (United States)

    Li, Hongjun; Yin, Hao; Gong, Xiangwu; Dong, Feihong; Ren, Baoquan; He, Yuanzhi; Wang, Jingchao

    2016-10-14

    This paper investigates the performance of integrated wireless sensor and multibeam satellite networks (IWSMSNs) under terrestrial interference. The IWSMSNs constitute sensor nodes (SNs), satellite sinks (SSs), multibeam satellite and remote monitoring hosts (RMHs). The multibeam satellite covers multiple beams and multiple SSs in each beam. The SSs can be directly used as SNs to transmit sensing data to RMHs via the satellite, and they can also be used to collect the sensing data from other SNs to transmit to the RMHs. We propose the hybrid one-dimensional (1D) and 2D beam models including the equivalent intra-beam interference factor β from terrestrial communication networks (TCNs) and the equivalent inter-beam interference factor α from adjacent beams. The terrestrial interference is possibly due to the signals from the TCNs or the signals of sinks being transmitted to other satellite networks. The closed-form approximations of capacity per beam are derived for the return link of IWSMSNs under terrestrial interference by using the Haar approximations where the IWSMSNs experience the Rician fading channel. The optimal joint decoding capacity can be considered as the upper bound where all of the SSs' signals can be jointly decoded by a super-receiver on board the multibeam satellite or a gateway station that knows all of the code books. While the linear minimum mean square error (MMSE) capacity is where all of the signals of SSs are decoded singularly by a multibeam satellite or a gateway station. The simulations show that the optimal capacities are obviously higher than the MMSE capacities under the same conditions, while the capacities are lowered by Rician fading and converge as the Rician factor increases. α and β jointly affect the performance of hybrid 1D and 2D beam models, and the number of SSs also contributes different effects on the optimal capacity and MMSE capacity of the IWSMSNs.

  10. Effectiveness of a Satellite Educational Television Program for Ethiopian Secondary Education

    Science.gov (United States)

    Kim, Sung-Wan

    2015-01-01

    This study examined the actual practice and effectiveness of a satellite educational TV program in Ethiopian secondary schools. Participants in the survey were 228 students and 63 teachers from secondary schools. The results of the data analysis indicate that Ethiopian students and teachers scored highly in the evaluation areas. Levels of…

  11. A guide to the literature on application of communications satellites to educational development

    Science.gov (United States)

    Morgan, R. P.; Singh, J. P.

    1972-01-01

    A review of literature dealing with communication satellite technology is presented for the nontechnical reader with emphasis on the educational aspects. An introduction is provided for: satellite technology; nontechnological aspects including economic, organizational, social, and political factors; and educational and developmental uses. A guide to selected literature, and a bibliography are included.

  12. The Use of Communication Satellites for Distance Education: A World Perspective.

    Science.gov (United States)

    Coldevin, Gary; Amundsen, Cheryl

    1985-01-01

    Reviews communications satellites configurations (point-to-point, distribution, and direct broadcast)and presents an overview of primary uses for satellite communications worldwide, including extension of preparatory and first year university courses; inservice teacher, professional, and continuing education; non-formal education; primary level…

  13. Iowa Communications Network Enhancing Education in Iowa.

    Science.gov (United States)

    Ivanovic, Greta

    1995-01-01

    Describes the Iowa Communications Network, a statewide fiber optic network capable of transporting interactive, two-way audio, video, voice, and data signals. Topics include statewide cooperation among educational and state organizations; classroom design, including interactive classrooms; access to the Internet; and use by noneducational…

  14. Requirements analysis and design for implementation of a satellite link for a local area computer network

    OpenAIRE

    Lorentzen, Richard B.

    1991-01-01

    Approved for public release; distribution is unlimited The purpose of this thesis is to provide naval computer students with a basic knowledge on Very Small Aperture Terminal (VSAT) satellite technology and to define the hardware and software requirements at the interface between a VSAT and a Local Area Network (LAN). By restricting a computer network to terrestrial links, a vast amount of knowledge is not accessed because either the terrestrial links can't access the information or the...

  15. Protocol Support for a New Satellite-Based Airspace Communication Network

    Science.gov (United States)

    Shang, Yadong; Hadjitheodosiou, Michael; Baras, John

    2004-01-01

    We recommend suitable transport protocols for an aeronautical network supporting Internet and data services via satellite. We study the characteristics of an aeronautical satellite hybrid network and focus on the problems that cause dramatically degraded performance of the Transport Protocol. We discuss various extensions to standard TCP that alleviate some of these performance problems. Through simulation, we identify those TCP implementations that can be expected to perform well. Based on the observation that it is difficult for an end-to-end solution to solve these problems effectively, we propose a new TCP-splitting protocol, termed Aeronautical Transport Control Protocol (AeroTCP). The main idea of this protocol is to use a fixed window for flow control and one duplicated acknowledgement (ACK) for fast recovery. Our simulation results show that AeroTCP can maintain higher utilization for the satellite link than end-to-end TCP, especially in high BER environment.

  16. A Handover Strategy in the LEO Satellite-Based Constellation Networks with ISLs

    Institute of Scientific and Technical Information of China (English)

    LIU Gang; GOU Dingyong; WU Shiqi

    2003-01-01

    A new handover strategy named minimal-hops handover(MHH) strategy for the low earth orbit(LEO) satellite constellations networks equipped with inter-satellite links(ISLs) is proposed.MHH strategy, which is based on the hops of the end-to-end connection paths and makes good use of the regularity of the constellation network topology, can appropriately combine the handover procedure with routing and efficiently solve the inter-satellite handover issue. Moreover, MHH strategy can provide quality of services( QoS) guarantees to some extent. The system performances of the MHH strategy, such as time propagation delay and handover frequency, are evaluated and compared with that of other previous strategies. The simulation results show that MHH strategy performs better than other previous handover strategies.

  17. The performance evaluation of a new neural network based traffic management scheme for a satellite communication network

    Science.gov (United States)

    Ansari, Nirwan; Liu, Dequan

    1991-01-01

    A neural-network-based traffic management scheme for a satellite communication network is described. The scheme consists of two levels of management. The front end of the scheme is a derivation of Kohonen's self-organization model to configure maps for the satellite communication network dynamically. The model consists of three stages. The first stage is the pattern recognition task, in which an exemplar map that best meets the current network requirements is selected. The second stage is the analysis of the discrepancy between the chosen exemplar map and the state of the network, and the adaptive modification of the chosen exemplar map to conform closely to the network requirement (input data pattern) by means of Kohonen's self-organization. On the basis of certain performance criteria, whether a new map is generated to replace the original chosen map is decided in the third stage. A state-dependent routing algorithm, which arranges the incoming call to some proper path, is used to make the network more efficient and to lower the call block rate. Simulation results demonstrate that the scheme, which combines self-organization and the state-dependent routing mechanism, provides better performance in terms of call block rate than schemes that only have either the self-organization mechanism or the routing mechanism.

  18. The method of the antenna system positioning for satellite communication network radiomonitoring complex

    OpenAIRE

    Гребенюк, Олег Петрович

    2014-01-01

    The method of orientation of the antenna system of complex of radiomonitoring of satellite communication networks is offered. A method takes into account the features of construction and functional setting of a transport stream of standard of DVB ‑ S.

  19. TOLNet - A Tropospheric Ozone Lidar Profiling Network for Satellite Continuity and Process Studies

    Science.gov (United States)

    Newchurch, Michael J.; Kuang, Shi; Wang, Lihua; LeBlanc, Thierry; Alvarez II, Raul J.; Langford, Andrew O.; Senff, Christoph J.; Brown, Steve; Johnson, Bryan; Burris, John F.; hide

    2015-01-01

    NASA initiated an interagency ozone lidar observation network under the name TOLNet to promote cooperative multiple-station ozone-lidar observations to provide highly time-resolved (few minutes) tropospheric-ozone vertical profiles useful for air-quality studies, model evaluation, and satellite validation.

  20. Geometric Aspects of Ground Augmentation of Satellite Networks for the Needs of Deformation Monitoring

    Science.gov (United States)

    Protaziuk, Elżbieta

    2016-06-01

    Satellite measurements become competitive in many tasks of engineering surveys, however, in many requiring applications possibilities to apply such solutions are still limited. The possibility to widely apply satellite technologies for displacements measurements is related with new challenges; the most important of them relate to increasing requirements concerning the accuracy, reliability and continuity of results of position determination. One of the solutions is a ground augmentation of satellite network, which intention is to improve precision of positioning, ensure comparable accuracy of coordinates and reduce precision fluctuations over time. The need for augmentation of GNSS is particularly significant in situations: where the visibility of satellites is poor because of terrain obstacles, when the determined position is not precise enough or a satellites constellation does not allow for reliable positioning. Ground based source/sources of satellite signal placed at a ground, called pseudosatellites, or pseudolites were intensively investigated during the last two decades and finally were developed into groundbased, time-synchronized transceivers, that can transmit and receive a proprietary positioning signal. The paper presents geometric aspects of the ground based augmentation of the satellite networks using various quality measures of positioning geometry, which depends on access to the constellation of satellites and the conditions of the observation environment. The issue of minimizing these measures is the key problem that allows to obtain the position with high accuracy. For this purpose, the use of an error ellipsoid is proposed and compared with an error ellipse. The paper also describes the results of preliminary accuracy analysis obtained at test area and a comparison of various measures of the quality of positioning geometry.

  1. Connectivism: the educational theory of networks

    Directory of Open Access Journals (Sweden)

    Enrico Bocciolesi

    2013-12-01

    Full Text Available The significant use of electronic media in everyday life requires new considerations about learning, about communication, about being in the spaces of ubiquity. Siemenes (2005 proposed the theory of networks, the learning through networks, the connections between nodes, which Landow (2006, Bolter (1991, 1996, 2001, Cassany (2012 have at different times called even if other terms. The relevance of the theory of Connectivism offers new fields of investigation and experimentation for the area of education, which deserve reflections and insights that enable to validate, based on the need for education and training simultaneous, the applicability of a theory of networks.

  2. Application of communications satellites to educational development. [technology utilization/information systems - bibliographies

    Science.gov (United States)

    Morgan, R. P.

    1975-01-01

    A summary of research is presented. The broad objectives of this interdisciplinary research effort were: (1) to assess the role of satellite communications as a means of improving education in the United States, as well as in less-developed areas of the world; (2) to generate basic knowledge which will aid in making rational decisions about satellite application in the field of education in the years ahead; (3) to devise systems and strategies for improving education; and (4) to educate individuals who will be knowledgeable about aspects of satellite communications policy which transcend any single discipline.

  3. Neural network based satellite tracking for deep space applications

    Science.gov (United States)

    Amoozegar, F.; Ruggier, C.

    2003-01-01

    The objective of this paper is to provide a survey of neural network trends as applied to the tracking of spacecrafts in deep space at Ka-band under various weather conditions and examine the trade-off between tracing accuracy and communication link performance.

  4. A gradual neural-network approach for frequency assignment in satellite communication systems.

    Science.gov (United States)

    Funabiki, N; Nishikawa, S

    1997-01-01

    A novel neural-network approach called gradual neural network (GNN) is presented for a class of combinatorial optimization problems of requiring the constraint satisfaction and the goal function optimization simultaneously. The frequency assignment problem in the satellite communication system is efficiently solved by GNN as the typical problem of this class. The goal of this NP-complete problem is to minimize the cochannel interference between satellite communication systems by rearranging the frequency assignment so that they can accommodate the increasing demands. The GNN consists of NxM binary neurons for the N-carrier-M-segment system with the gradual expansion scheme of activated neurons. The binary neural network achieves the constrain satisfaction with the help of heuristic methods, whereas the gradual expansion scheme seeks the cost optimization. The capability of GNN is demonstrated through solving 15 instances in practical size systems, where GNN can find far better solutions than the existing algorithm.

  5. Networked Operations of Hybrid Radio Optical Communications Satellites

    Science.gov (United States)

    Hylton, Alan; Raible, Daniel

    2014-01-01

    In order to address the increasing communications needs of modern equipment in space, and to address the increasing number of objects in space, NASA is demonstrating the potential capability of optical communications for both deep space and near-Earth applications. The Integrated Radio Optical Communications (iROC) is a hybrid communications system that capitalizes on the best of both the optical and RF domains while using each technology to compensate for the other's shortcomings. Specifically, the data rates of the optical links can be higher than their RF counterparts, whereas the RF links have greater link availability. The focus of this paper is twofold: to consider the operations of one or more iROC nodes from a networking point of view, and to suggest specific areas of research to further the field. We consider the utility of Disruption Tolerant Networking (DTN) and the Virtual Mission Operation Center (VMOC) model.

  6. PEACESAT (Pan Pacific Education and Communication Experiments by Satellite) Project Early Experience: The Design and Early Years of the First Educational Communication Satellite Experiment. Report 1.

    Science.gov (United States)

    Hawaii Univ., Honolulu.

    The PEACESAT Project (Pan Pacific Education and Communication Experiments by Satellite) has been in daily operation for four years since April 1971. Initiated as an individual research project of a university faculty member, it has expanded to involve educational institutions in 12 countries or jurisdictions in the Pacific Basin. These…

  7. Educational Benefits From the AAU-cubesat Student Satellite Project

    DEFF Research Database (Denmark)

    Alminde, Lars

    2003-01-01

    In September 2001 Aalborg university started the AAU-cubesat project that reached it climax when the student built satellite was launched into space on the 30th of June 2003 on top of a former Russian ICBM. AAU-cubesat was among the first five satellites to be launched that are built within...... the cubesat concept that prescribes a satellite with dimensions 10x10x10cm and mass one kilogram. These constraints clearly limits the possibilities for the satellite in terms of possible scientific missions, but on the other hand: by building satellites of this size a technology push is created...... that in the future will help to reduce the size of both scientific and commercial satellites and thus help to drive down the launch cost. This paper will describe the overall architecture of the AAU-cubesat. Results from the operation phase will be stated, and recommendations on further work on pico-satellite...

  8. Amazon Rainforest Deforestation Daily Detection Tool Using Artificial Neural Networks and Satellite Images

    Directory of Open Access Journals (Sweden)

    Silvio César Cazella

    2012-10-01

    Full Text Available The main purpose of this work was the development of a tool to detect daily deforestation in the Amazon rainforest, using satellite images from the MODIS/TERRA [1] sensor and Artificial Neural Networks. The developed tool provides the parameterization of the configuration for the neural network training to enable us to find the best neural architecture to address the problem. The tool makes use of confusion matrixes to determine the degree of success of the network. Part of the municipality of Porto Velho, in Rondônia state, is located inside the tile H11V09 of the MODIS/TERRA sensor, which was used as the study area. A spectrum-temporal analysis of this area was made on 57 images from 20 of May to 15 of July 2003 using the trained neural network. This analysis allowed us to verify the quality of the implemented neural network classification as well as helping our understanding of the dynamics of deforestation in the Amazon rainforest. The great potential of neural networks for image classification was perceived with this work. However, the generation of consistent alarms, in other words, detecting predatory actions at the beginning; instead of firing false alarms is a complex task that has not yet been solved. Therefore, the major contribution of this paper is to provide a theoretical basis and practical use of neural networks and satellite images to combat illegal deforestation.

  9. Research on handover algorithm to reduce the blocking probability in LEO satellite network

    Institute of Scientific and Technical Information of China (English)

    Chen Bingcai; Zhang Naitong; Nie Boxun; Zhou Tingxian

    2006-01-01

    Based on the characteristics of guaranteed handover (GH) algorithm, the finite capacity in one system makes the blocking probability (PB) of GH algorithm increase rapidly in the case of high traffic load. So, when large amounts of multimedia services are transmitted via a single low earth orbit (LEO) satellite system, the PB of it is much higher. In order to solve the problem, a novel handover scheme defined by multi-tier optiral layer selection is proposed. The scheme sufficienfly takes into ac count the characteristics of double-tier satellite network, which is constituted by LEO satellites combined with medium earth orbit (MEO) satellites, and the multimedia transmitted by such network, so it can augment this systematic capacity and effectively reduces the traffic load in the LEO which performs GH algorithm. The detailed processes are also presented. The simulation and numerical results show that the approach integrated with GH algorithm achieves a significant improvement in the PB and practicability, as compared to the single LEO layer network.

  10. TOLNET – A Tropospheric Ozone Lidar Profiling Network for Satellite Continuity and Process Studies

    Directory of Open Access Journals (Sweden)

    Newchurch Michael J.

    2016-01-01

    Full Text Available Ozone lidars measure continuous, high-resolution ozone profiles critical for process studies and for satellite validation in the lower troposphere. However, the effectiveness of lidar validation by using single-station data is limited. Recently, NASA initiated an interagency ozone lidar observation network under the name TOLNet to promote cooperative multiple-station ozone-lidar observations to provide highly timeresolved (few minutes tropospheric-ozone vertical profiles useful for air-quality studies, model evaluation, and satellite validation. This article briefly describes the concept, stations, major specifications of the TOLNet instruments, and data archiving.

  11. Diversity reception for advanced multi-satellite networks: A CDMA approach

    Science.gov (United States)

    Colzi, E.; Degaudenzi, R.; Elia, C.; Giannetti, F.; Viola, R.

    1993-01-01

    Diversity reception for Synchronous CDMA (S-CDMA) is introduced and analyzed. A Gaussian co-channel synchronous and asynchronous interference approximation is derived to evaluate the effects on the system bit error rate. Numerical results are provided for a simple mobile communication system where the signals transmitted by two distinct satellites in visibility are coherently combined by a three fingers Rake receiver. A second example showing performance of an integrated ground/satellite single frequency network for digital audio broadcasting is presented. Results show the capacity advantage of utilizing S-CDMA in combination with diversity reception.

  12. Satellite image processing for precision agriculture and agroindustry using convolutional neural network and genetic algorithm

    Science.gov (United States)

    Firdaus; Arkeman, Y.; Buono, A.; Hermadi, I.

    2017-01-01

    Translating satellite imagery to a useful data for decision making during this time are usually done manually by human. In this research, we are going to translate satellite imagery by using artificial intelligence method specifically using convolutional neural network and genetic algorithm to become a useful data for decision making, especially for precision agriculture and agroindustry. In this research, we are focused on how to made a sustainable land use planning with 3 objectives. The first is maximizing economic factor. Second is minimizing CO2 emission and the last is minimizing land degradation. Results show that by using artificial intelligence method, can produced a good pareto optimum solutions in a short time.

  13. Diversity reception for advanced multi-satellite networks: A CDMA approach

    Science.gov (United States)

    Colzi, E.; Degaudenzi, R.; Elia, C.; Giannetti, F.; Viola, R.

    Diversity reception for Synchronous CDMA (S-CDMA) is introduced and analyzed. A Gaussian co-channel synchronous and asynchronous interference approximation is derived to evaluate the effects on the system bit error rate. Numerical results are provided for a simple mobile communication system where the signals transmitted by two distinct satellites in visibility are coherently combined by a three fingers Rake receiver. A second example showing performance of an integrated ground/satellite single frequency network for digital audio broadcasting is presented. Results show the capacity advantage of utilizing S-CDMA in combination with diversity reception.

  14. Satellite Radar Interferometry For Risk Management Of Gas Pipeline Networks

    Science.gov (United States)

    Ianoschi, Raluca; Schouten, Mathijs; Bas Leezenberg, Pieter; Dheenathayalan, Prabu; Hanssen, Ramon

    2013-12-01

    InSAR time series analyses can be fine-tuned for specific applications, yielding a potential increase in benchmark density, precision and reliability. Here we demonstrate the algorithms developed for gas pipeline monitoring, enabling operators to precisely pinpoint unstable locations. This helps asset management in planning, prioritizing and focusing in-situ inspections, thus reducing maintenance costs. In unconsolidated Quaternary soils, ground settlement contributes to possible failure of brittle cast iron gas pipes and their connections to houses. Other risk factors include the age and material of the pipe. The soil dynamics have led to a catastrophic explosion in the city of Amsterdam, which triggered an increased awareness for the significance of this problem. As the extent of the networks can be very wide, InSAR is shown to be a valuable source of information for identifying the hazard regions. We monitor subsidence affecting an urban gas transportation network in the Netherlands using both medium and high resolution SAR data. Results for the 2003-2010 period provide clear insights on the differential subsidence rates in the area. This enables characterization of underground motion that affects the integrity of the pipeline. High resolution SAR data add extra detail of door-to-door pipeline connections, which are vulnerable due to different settlements between house connections and main pipelines. The rates which we measure represent important input in planning of maintenance works. Managers can decide the priority and timing for inspecting the pipelines. The service helps manage the risk and reduce operational cost in gas transportation networks.

  15. Extraction of DTM from Satellite Images Using Neural Networks

    OpenAIRE

    Tapper, Gustav

    2016-01-01

    This thesis presents a way to generate a Digital Terrain Model (dtm) from a Digital Surface Model (dsm) and multi spectral images (including the Near Infrared (nir) color band). An Artificial Neural Network (ann) is used to pre-classify the dsm and multi spectral images. This in turn is used to filter the dsm to a dtm. The use of an ann as a classifier provided good results. Additionally, the addition of the nir color band resulted in an improvement of the accuracy of the classifier. Using th...

  16. Ku-band satellite data networks using very small aperture terminals. II - System design

    Science.gov (United States)

    Raychaudhuri, D.

    1987-12-01

    An overview is presented of system design for Ku-band star networks intended for interactive data applications. The component elements of such a network are discussed, and the critical items for performance, capacity, and cost are identified. A systematic design procedure combining delay-throughput characterization of the multiaccess inbound and TDM outbound channels with satellite link analysis is provided by which system components and their parameters are selected once the network response time and availability objectives are specified. The results are presented in the form of charts and tables which may serve as the basis for star network design over a range of typical traffic models, component parameters, and performance objectives. The methodology is potentially useful for evaluating alternative network architectures and traffic scenarios which may become important as VSAT technology evolves.

  17. Dynamic autonomous routing technology for IP-based satellite ad hoc networks

    Science.gov (United States)

    Wang, Xiaofei; Deng, Jing; Kostas, Theresa; Rajappan, Gowri

    2014-06-01

    IP-based routing for military LEO/MEO satellite ad hoc networks is very challenging due to network and traffic heterogeneity, network topology and traffic dynamics. In this paper, we describe a traffic priority-aware routing scheme for such networks, namely Dynamic Autonomous Routing Technology (DART) for satellite ad hoc networks. DART has a cross-layer design, and conducts routing and resource reservation concurrently for optimal performance in the fluid but predictable satellite ad hoc networks. DART ensures end-to-end data delivery with QoS assurances by only choosing routing paths that have sufficient resources, supporting different packet priority levels. In order to do so, DART incorporates several resource management and innovative routing mechanisms, which dynamically adapt to best fit the prevailing conditions. In particular, DART integrates a resource reservation mechanism to reserve network bandwidth resources; a proactive routing mechanism to set up non-overlapping spanning trees to segregate high priority traffic flows from lower priority flows so that the high priority flows do not face contention from low priority flows; a reactive routing mechanism to arbitrate resources between various traffic priorities when needed; a predictive routing mechanism to set up routes for scheduled missions and for anticipated topology changes for QoS assurance. We present simulation results showing the performance of DART. We have conducted these simulations using the Iridium constellation and trajectories as well as realistic military communications scenarios. The simulation results demonstrate DART's ability to discriminate between high-priority and low-priority traffic flows and ensure disparate QoS requirements of these traffic flows.

  18. Satellite clock corrections estimation to accomplish real time ppp: experiments for brazilian real time network

    Science.gov (United States)

    Marques, Haroldo; Monico, João; Aquino, Marcio; Melo, Weyller

    2014-05-01

    The real time PPP method requires the availability of real time precise orbits and satellites clocks corrections. Currently, it is possible to apply the solutions of clocks and orbits available by BKG within the context of IGS Pilot project or by using the operational predicted IGU ephemeris. The accuracy of the satellite position available in the IGU is enough for several applications requiring good quality. However, the satellites clocks corrections do not provide enough accuracy (3 ns ~ 0.9 m) to accomplish real time PPP with the same level of accuracy. Therefore, for real time PPP application it is necessary to further research and develop appropriated methodologies for estimating the satellite clock corrections in real time with better accuracy. Currently, it is possible to apply the real time solutions of clocks and orbits available by Federal Agency for Cartography and Geodesy (BKG) within the context of IGS Pilot project. The BKG corrections are disseminated by a new proposed format of the RTCM 3.x and can be applied in the broadcasted orbits and clocks. Some investigations have been proposed for the estimation of the satellite clock corrections using GNSS code and phase observable at the double difference level between satellites and epochs (MERVAT, DOUSA, 2007). Another possibility consists of applying a Kalman Filter in the PPP network mode (HAUSCHILD, 2010) and it is also possible the integration of both methods, using network PPP and observables at double difference level in specific time intervals (ZHANG; LI; GUO, 2010). For this work the methodology adopted consists in the estimation of the satellite clock corrections based on the data adjustment in the PPP mode, but for a network of GNSS stations. The clock solution can be solved by using two types of observables: code smoothed by carrier phase or undifferenced code together with carrier phase. In the former, we estimate receiver clock error; satellite clock correction and troposphere, considering

  19. SM_TCP: a new reliable multicast transport protocol for satellite IP networks

    Science.gov (United States)

    Liu, Gongliang; Gu, Xuemai; Li, Shizhong

    2005-11-01

    A new reliable multicast transport protocol SM_TCP is proposed for satellite IP networks in this paper. In SM_TCP, the XOR scheme with the aid of on-board buffering and processing is used for error recovery and an optimal retransmission algorithm is designed, which can reduce the recovery time by half of the RTT and minimize the number of retransmissions. In order to avoid the unnecessary decrease of congestion window in the high BER satellite channels, the occupied buffer sizes at bottlenecks are measured in adjusting the congestion window, instead of depending on the packet loss information. The average session rate of TCP sessions and of multicast sessions passing through the satellite are also measured and compared in adjusting the congestion window, which contributes to bandwidth fairness. Analysis and simulation results show fairness with TCP flows and scalability.

  20. A Topology Control Strategy with Reliability Assurance for Satellite Cluster Networks in Earth Observation.

    Science.gov (United States)

    Chen, Qing; Zhang, Jinxiu; Hu, Ze

    2017-02-23

    This article investigates the dynamic topology control problemof satellite cluster networks (SCNs) in Earth observation (EO) missions by applying a novel metric of stability for inter-satellite links (ISLs). The properties of the periodicity and predictability of satellites' relative position are involved in the link cost metric which is to give a selection criterion for choosing the most reliable data routing paths. Also, a cooperative work model with reliability is proposed for the situation of emergency EO missions. Based on the link cost metric and the proposed reliability model, a reliability assurance topology control algorithm and its corresponding dynamic topology control (RAT) strategy are established to maximize the stability of data transmission in the SCNs. The SCNs scenario is tested through some numeric simulations of the topology stability of average topology lifetime and average packet loss rate. Simulation results show that the proposed reliable strategy applied in SCNs significantly improves the data transmission performance and prolongs the average topology lifetime.

  1. The Role of Communication Satellites in Education and Training: The 1990s.

    Science.gov (United States)

    Polcyn, Kenneth A.

    1981-01-01

    Presents an overview of satellite technology and trends in its use, reviews the evolution of education and training applications of communication satellites, and prognosticates about the possible national and international uses during the 1990s. A bibliography of 26 items is included. (CHC)

  2. Design for an Analysis and Assessment of the Education Satellite Communications Demonstration: Final Report.

    Science.gov (United States)

    Practical Concepts, Inc., Washington, DC.

    A 3-month evaluation design effort developed a strategy and implementation plan for a policy level evaluation of the Educational Satellite Communications Demonstration (ESCD). The final report of the effort covers: (1) development of the evaluation strategy and plan; (2) data collection and analysis; (3) measurement of the impact of satellite TV…

  3. The Communications Satellite - Vehicle for a New Kind of Reciprocal Interdependence in International Adult Education

    Science.gov (United States)

    Wedemeyer, Charles A.

    1971-01-01

    Adult education by means of communication satellites is stressed as a key to reciprocal interdependence. The author states that technological advances such as communications satellites can be used effectively to diffuse knowledge and offer options for choice in evolving societies. (RR)

  4. COMMUNICATION SATELLITES FOR EDUCATION, SCIENCE AND CULTURE. REPORTS AND PAPERS ON MASS COMMUNICATION, NO. 53.

    Science.gov (United States)

    SCHRAMM, WILBUR

    THE TECHNOLOGY OF COMMUNICATION SATELLITES IS SUFFICIENTLY ADVANCED THAT CONCERNED AGENCIES, SUCH AS UNESCO, SHOULD BEGIN TO PLAN FOR THEIR USE IN EXCHANGE OF DATA, NEWS TRANSMISSION, CULTURAL EXCHANGE, AND EDUCATION. GROUNDWORK IN TECHNOLOGY, IN THE DESIGN OF A SATELLITE COMMUNICATION SYSTEM, IN VALUE JUDGMENTS, IN AGREEMENTS OF COOPERATION AND…

  5. The Role of Communication Satellites in Education and Training: The 1990s.

    Science.gov (United States)

    Polcyn, Kenneth A.

    1981-01-01

    Presents an overview of satellite technology and trends in its use, reviews the evolution of education and training applications of communication satellites, and prognosticates about the possible national and international uses during the 1990s. A bibliography of 26 items is included. (CHC)

  6. A Guide to the Literature on Application of Communications Satellites to Educational Development.

    Science.gov (United States)

    Morgan, Robert P.; Singh, Jai P.

    Because of the ability of communications satellites to distribute electronic information (radio, television, digital computer data) over wide areas with potentially attractive costs, considerable interest has been shown in using satellite technology to enhance educational programs, both in the United States and in other countries. In view of these…

  7. A space weather forecasting system with multiple satellites based on a self-recognizing network.

    Science.gov (United States)

    Tokumitsu, Masahiro; Ishida, Yoshiteru

    2014-05-05

    This paper proposes a space weather forecasting system at geostationary orbit for high-energy electron flux (>2 MeV). The forecasting model involves multiple sensors on multiple satellites. The sensors interconnect and evaluate each other to predict future conditions at geostationary orbit. The proposed forecasting model is constructed using a dynamic relational network for sensor diagnosis and event monitoring. The sensors of the proposed model are located at different positions in space. The satellites for solar monitoring equip with monitoring devices for the interplanetary magnetic field and solar wind speed. The satellites orbit near the Earth monitoring high-energy electron flux. We investigate forecasting for typical two examples by comparing the performance of two models with different numbers of sensors. We demonstrate the prediction by the proposed model against coronal mass ejections and a coronal hole. This paper aims to investigate a possibility of space weather forecasting based on the satellite network with in-situ sensing.

  8. A Space Weather Forecasting System with Multiple Satellites Based on a Self-Recognizing Network

    Directory of Open Access Journals (Sweden)

    Masahiro Tokumitsu

    2014-05-01

    Full Text Available This paper proposes a space weather forecasting system at geostationary orbit for high-energy electron flux (>2 MeV. The forecasting model involves multiple sensors on multiple satellites. The sensors interconnect and evaluate each other to predict future conditions at geostationary orbit. The proposed forecasting model is constructed using a dynamic relational network for sensor diagnosis and event monitoring. The sensors of the proposed model are located at different positions in space. The satellites for solar monitoring equip with monitoring devices for the interplanetary magnetic field and solar wind speed. The satellites orbit near the Earth monitoring high-energy electron flux. We investigate forecasting for typical two examples by comparing the performance of two models with different numbers of sensors. We demonstrate the prediction by the proposed model against coronal mass ejections and a coronal hole. This paper aims to investigate a possibility of space weather forecasting based on the satellite network with in-situ sensing.

  9. CloudSat Education Network: Partnerships for Outreach

    Science.gov (United States)

    TeBockhorst, D.

    2014-12-01

    CloudSat Education Network (CEN): Partnerships to improve the understanding of clouds in formal and informal settings. Since The CloudSat satellite launched in 2006 the Formal and Informal education programs for the mission have been focused on bringing an understanding about the mission science and the importance of clouds, climate & weather science. This has been done by creating and strengthening partnership and collaboration within scientific and educational communities around the country and the world. Because CloudSat was formally recognized as a Earth System Science Pathfinder campaign with the GLOBE program, the CEN developed a set of field protocols for student observations that augmented the GLOBE atmosphere protocols when there was a satellite overpass. This shared process between GLOBE & CloudSat resulted in the training & creation of CEN schools that are both GLOBE schools and CloudSat schools, and also produced three GLOBE partnerships that specialize in cloud science education and outreach. In addition, the CEN has developed productive relationships with other NASA missions and EPO teams. Specifically, in collaboration with the NASA CERES mission projects S'Cool and MyNASAData, we have co-presented at NSTA conferences and with schools participating in a NASA EPOESS-funded formal education project. This collaborative work has been a very real benefit to a wide variety of audiences needing to strengthen their understanding of clouds and their roles in the earth system, and we hope will serve as a model to future missions looking to involve the public in mission science.

  10. Aviation-oriented Mobility Management Method in IP/LEO Satellite Networks

    Institute of Scientific and Technical Information of China (English)

    Guo Xin; Zhang Jun; Zhang Tao; Ding Yanwen

    2008-01-01

    Taking into chief consideration the features of aviation nodes in satellite networks,such as high moving speed,long communication distance,and high connection frequency,this article proposes an aviatiun-oriented mobility management method for IP/low earth orbit (LEO) satellite networks.By introducing the concept of ground station real-time coverage area,the proposed method uses ground-station-based IP addressing method and cell paging scheme to decrease the frequency of IP binding update requests as well as the paging cost.In comparison with the paging mobile IP (P-MIP) method and the handover-independent IP mobility management method,as is verified by the mathematical analysis and simulation,the proposed method could decrease the management cost.It also possesses better ability to support the aviation nodes because it is subjected to fewer influences from increased node speeds and newly coming connection rates.

  11. Reconstruction of an infrared band of meteorological satellite imagery with abductive networks

    Science.gov (United States)

    Singer, Harvey A.; Cockayne, John E.; Versteegen, Peter L.

    1995-01-01

    As the current fleet of meteorological satellites age, the accuracy of the imagery sensed on a spectral channel of the image scanning system is continually and progressively degraded by noise. In time, that data may even become unusable. We describe a novel approach to the reconstruction of the noisy satellite imagery according to empirical functional relationships that tie the spectral channels together. Abductive networks are applied to automatically learn the empirical functional relationships between the data sensed on the other spectral channels to calculate the data that should have been sensed on the corrupted channel. Using imagery unaffected by noise, it is demonstrated that abductive networks correctly predict the noise-free observed data.

  12. A hybrid hopfield network-simulated annealing approach for frequency assignment in satellite communications systems.

    Science.gov (United States)

    Salcedo-Sanz, Sancho; Santiago-Mozos, Ricardo; Bousoño-Calzón, Carlos

    2004-04-01

    A hybrid Hopfield network-simulated annealing algorithm (HopSA) is presented for the frequency assignment problem (FAP) in satellite communications. The goal of this NP-complete problem is minimizing the cochannel interference between satellite communication systems by rearranging the frequency assignment, for the systems can accommodate the increasing demands. The HopSA algorithm consists of a fast digital Hopfield neural network which manages the problem constraints hybridized with a simulated annealing which improves the quality of the solutions obtained. We analyze the problem and its formulation, describing and discussing the HopSA algorithm and solving a set of benchmark problems. The results obtained are compared with other existing approaches in order to show the performance of the HopSA approach.

  13. Classification and Segmentation of Satellite Orthoimagery Using Convolutional Neural Networks

    Directory of Open Access Journals (Sweden)

    Martin Längkvist

    2016-04-01

    Full Text Available The availability of high-resolution remote sensing (HRRS data has opened up the possibility for new interesting applications, such as per-pixel classification of individual objects in greater detail. This paper shows how a convolutional neural network (CNN can be applied to multispectral orthoimagery and a digital surface model (DSM of a small city for a full, fast and accurate per-pixel classification. The predicted low-level pixel classes are then used to improve the high-level segmentation. Various design choices of the CNN architecture are evaluated and analyzed. The investigated land area is fully manually labeled into five categories (vegetation, ground, roads, buildings and water, and the classification accuracy is compared to other per-pixel classification works on other land areas that have a similar choice of categories. The results of the full classification and segmentation on selected segments of the map show that CNNs are a viable tool for solving both the segmentation and object recognition task for remote sensing data.

  14. Using Satellite Images for Wireless Network Planing in Baku City

    Science.gov (United States)

    Gojamanov, M.; Ismayilov, J.

    2013-04-01

    It is a well known fact that the Information-Telecommunication and Space research technologies are the fields getting much more benefits from the achievements of the scientific and technical progress. In many cases, these areas supporting each other have improved the conditions for their further development. For instance, the intensive development in the field of the mobile communication has caused the rapid progress of the Space research technologies and vice versa.Today it is impossible to solve one of the most important tasks of the mobile communication as Radio Frecance planning without the 2D and 3D digital maps. The compiling of such maps is much more efficient by means of the space images. Because the quality of the space images has been improved and developed, especially at the both spectral and spatial resolution points. It has been possible to to use 8 Band images with the spatial resolution of 50 sm. At present, in relation to the function 3G of mobile communications one of the main issues facing mobile operator companies is a high-precision 3D digital maps. It should be noted that the number of mobile phone users in the Republic of Azerbaijan went forward other Community of Independent States Countries. Of course, using of aerial images for 3D mapping would be optimal. However, depending on a number of technical and administrative problems aerial photography cannot be used. Therefore, the experience of many countries shows that it will be more effective to use the space images with the higher resolution for these issues. Concerning the fact that the mobile communication within the city of Baku has included 3G function there were ordered stereo images wih the spatial resolution of 50 cm for the 150 sq.km territory occupying the central part of the city in order to compile 3D digital maps. The images collected from the WorldView-2 satellite are 4-Band Bundle(Pan+MS1) stereo images. Such kind of imagery enable to automatically classificate some required

  15. Mathematical Education in the Network Environment

    Directory of Open Access Journals (Sweden)

    V. A. Testov

    2013-01-01

    Full Text Available The transition to the new educational paradigm in mathematical education is associated with the widespread introduction of information and communication technologies in education. The traditional teaching forms, methods, means and content do not seem to correspond with the new paradigm and need the theoretical reconsideration. In author’s opinion, it should be based on the post-non-classical methodology incorporating the synergetic world outlook and soft modeling ideas. The modern educational environment and network space provide the vast opportunities for self-study and self-education. However, the data perception tends to become nonlinear; and the task of the school, in this case, is to provide the nonlinear systemization of educational information through self-organized systems. The Author argues that the problem solving should remain the main activity in mathematics teaching, especially for the students of mathematical profile; the projecting activity should not dominate and prevail over the problem solving. 

  16. Mathematical Education in the Network Environment

    Directory of Open Access Journals (Sweden)

    V. A. Testov

    2015-02-01

    Full Text Available The transition to the new educational paradigm in mathematical education is associated with the widespread introduction of information and communication technologies in education. The traditional teaching forms, methods, means and content do not seem to correspond with the new paradigm and need the theoretical reconsideration. In author’s opinion, it should be based on the post-non-classical methodology incorporating the synergetic world outlook and soft modeling ideas. The modern educational environment and network space provide the vast opportunities for self-study and self-education. However, the data perception tends to become nonlinear; and the task of the school, in this case, is to provide the nonlinear systemization of educational information through self-organized systems. The Author argues that the problem solving should remain the main activity in mathematics teaching, especially for the students of mathematical profile; the projecting activity should not dominate and prevail over the problem solving. 

  17. Multi-layered Security Approaches for a Modular Open Network Architecture-based Satellite

    OpenAIRE

    Shirley, Brandon; Young, Quinn; Wegner, Peter; Christensen, Jacob; Janicik, Jeffrey

    2014-01-01

    A growing trend in satellite development includes shortening the development lifecycle for hardware and software, cost reduction, and promoting reuse for future missions. Department of Defense (DoD) acquisition policies mandate system providers use Open Systems Architecture (OSA) where feasible. Modular Open Network Architecture (MONA) is a subset of OSA and paves the way to achieve cost reduction and reuse during a reduced development lifecycle. MONA approaches provide opportunities to enhan...

  18. TCP-ADaLR: TCP with adaptive delay and loss response for broadband GEO satellite networks

    OpenAIRE

    Omueti, Modupe Omogbohun

    2007-01-01

    Transmission Control Protocol (TCP) performance degrades in broadband geostationary satellite networks due to long propagation delays and high bit error rates. In this thesis, we propose TCP with algorithm modifications for adaptive delay and loss response (TCP-ADaLR) to improve TCP performance. TCP-ADaLR incorporates delayed acknowledgement mechanism recommended for Internet hosts. We evaluate and compare the performance of TCP-ADaLR, TCP SACK, and TCP NewReno, with and without delayed ackno...

  19. Defense Science Board Task Force on Military Satellite Communication and Tactical Networking. Executive Summary

    Science.gov (United States)

    2017-03-01

    product of the Defense Science Board (DSB). The DSB is a Federal Advisory Committee established to provide independent advice to the Secretary of Defense...December 2014, the Under Secretary of Defense for Acquisition, Technology, and Logistics (USD(AT&L)) signed the “Terms of Reference – Defense Science ...Board Task Force on Military Satellite Communication and Tactical Networking.” As a result, the Chairman of the Defense Science Board established a

  20. A QoS Architecture for DVB-RCS Next Generation Satellite Networks

    Directory of Open Access Journals (Sweden)

    Gayraud Thierry

    2007-01-01

    Full Text Available The standardization of a return channel via satellite (DVB-RCS and satellite community efforts in term of interoperability over the last few years leads to quite a positive outcome: geostationary satellite networks are intended to provide broadband access to interactive multimedia services in low-infrastructure areas. However, in order to take in account real-time multimedia traffic, an efficient resource management scheme is still necessary to maximize the scarce uplink capacities usage. To address this capacity issue, this paper proposes a complete DVB-RCS QoS architecture that is implemented, thanks to an emulation platform, and evaluated with real multimedia applications. This paper first gives an overview of the QoS architecture usually used in DVB-S/RCS satellite system, especially in layers 2 and 3. It then introduces the satellite system emulation used in the experimentation and its calibration. The main contribution of this work focuses on the signaling principle designed to allow applications to take benefit from the QoS features of the satellite system even if they are non-QoS aware. It is then shown how signaling in such QoS architecture allows the user to change dynamically the QoS of his application using QoS agent and QoS server applications even if the application is not QoS-aware. It is also given quantitative results related to such a dynamic QoS change in the experiments done on the satellite emulation system.

  1. A QoS Architecture for DVB-RCS Next Generation Satellite Networks

    Directory of Open Access Journals (Sweden)

    Pascal Berthou

    2007-12-01

    Full Text Available The standardization of a return channel via satellite (DVB-RCS and satellite community efforts in term of interoperability over the last few years leads to quite a positive outcome: geostationary satellite networks are intended to provide broadband access to interactive multimedia services in low-infrastructure areas. However, in order to take in account real-time multimedia traffic, an efficient resource management scheme is still necessary to maximize the scarce uplink capacities usage. To address this capacity issue, this paper proposes a complete DVB-RCS QoS architecture that is implemented, thanks to an emulation platform, and evaluated with real multimedia applications. This paper first gives an overview of the QoS architecture usually used in DVB-S/RCS satellite system, especially in layers 2 and 3. It then introduces the satellite system emulation used in the experimentation and its calibration. The main contribution of this work focuses on the signaling principle designed to allow applications to take benefit from the QoS features of the satellite system even if they are non-QoS aware. It is then shown how signaling in such QoS architecture allows the user to change dynamically the QoS of his application using QoS agent and QoS server applications even if the application is not QoS-aware. It is also given quantitative results related to such a dynamic QoS change in the experiments done on the satellite emulation system.

  2. Network of educational investigation: Teaching innovatio

    Directory of Open Access Journals (Sweden)

    Rosana de Pablo Redondo

    2011-04-01

    Full Text Available The new educational reality, with the introduction of the European Higher Education Area (EHEA; and new requirements for education require a rethinking of the teaching process, which will use new technologies as key instruments. However, the concept of educational innovation goes beyond the widespread use of Information Technologies (IT. Structural changes are needed in educational institutions, which must be reorganized according to a new paradigm.This paper presents the strategic transformation developed by the National University of Distance Education (UNED; which involves the introduction of new instruments, new methodologies for current and prospective students and a new network organizational structure that facilitates global access to content and new methodologies. We emphasize Teaching Innovation Network, with special attention to the Educational Innovation in Finance. It shows a real example of combination of institutional change and educational initiatives. It combines efforts towards a better service and attention to students and the rest of the university community. And last, but not least, this new paradigm it is not only feasible but efficient because improvements outweigh organizational implications and economic costs

  3. UNSUPERVISED CLASSIFICATION OF HIGH RESOLUTION SATELLITE IMAGERY BY SELF-ORGANIZING NEURAL NETWORK

    Directory of Open Access Journals (Sweden)

    ÁRPÁD BARSI

    2010-06-01

    Full Text Available The current paper discusses the importance of the modern high resolution satellite imagery. The acquired high amount of data must be processed by an efficient way, where the used Kohonen-type self-organizing map has been proven as a suitable tool. The paper gives an introduction to this interesting method. The tests have shown that the multispectral image information can be taken after a resampling step as neural network inputs, and then the derived network weights are able to evaluate the whole image with acceptable thematic accuracy.

  4. World-wide interactive access to scientific databases via satellite and terrestrial data network

    Science.gov (United States)

    Sanderson, T. R.; Albrecht, M. A.; Ciarlo, A.; Brett, M.; Blank, K.; Hughes, P. M. T.; Wallum, G.; Hills, H. K.; Green, J. L.; Mcguire, R. E.; hide

    1990-01-01

    In order to demonstrate the possibilities for scientific networking and data transfer, a first temporary satellite network link was installed between Czecholovakia and the European space operations center in Darmstadt, during the meeting of the inter-agency consultative group for space science in Prague. Several experiments to show interactive nature of the facility and the capability of the system were carried out, and it was proven that, despite the temporary nature of the installation, the planned demonstrations could be conducted in real time. Demonstrations included electronic mail message, orbit prediction and solar X-ray data. The results of the experiment provided insight into possibilities of data exchange.

  5. World-wide interactive access to scientific databases via satellite and terrestrial data network

    Science.gov (United States)

    Sanderson, T. R.; Albrecht, M. A.; Ciarlo, A.; Brett, M.; Blank, K.; Hughes, P. M. T.; Wallum, G.; Hills, H. K.; Green, J. L.; Mcguire, R. E.; Kamei, T.; Kiplinger, A.; Waite, J. H., Jr.

    1990-01-01

    In order to demonstrate the possibilities for scientific networking and data transfer, a first temporary satellite network link was installed between Czecholovakia and the European space operations center in Darmstadt, during the meeting of the inter-agency consultative group for space science in Prague. Several experiments to show interactive nature of the facility and the capability of the system were carried out, and it was proven that, despite the temporary nature of the installation, the planned demonstrations could be conducted in real time. Demonstrations included electronic mail message, orbit prediction and solar X-ray data. The results of the experiment provided insight into possibilities of data exchange.

  6. NATO Education and Training Network

    Science.gov (United States)

    2012-02-01

    i.e., both technically and procedurally) with the tactical forces when needed for short notice mobile mission rehearsal training and other integrated...permanent subscription provides standard access to the: • CFBLNet Blackbone (IPv4 ( IPv6 ) transport network) • CFBLNet CUE (Unclassified Enclave all...1 Type of service None Bind to host t.b.d. IPv6 (off) 4.4.7.2 JPERF Server unclassified Configuration Listen Port 5001 Client

  7. Proximity graph analysis for linear networks extraction from high-resolution satellite imagery

    Science.gov (United States)

    Skourikhine, Alexei N.

    2006-05-01

    Reliable and accurate methods for detection and extraction of linear network, such as road networks, in satellite imagery are essential to many applications. We present an approach to the road network extraction from high-resolution satellite imagery that is based on proximity graph analysis. We are jumping off from the classification provided by existing spectral and textural classification tools, which produce a set of candidate road patches. Then, constrained Delaunay triangulation and Chordal Axis transform are used to extract centerline characterization of the delineated candidate road patches. We refine produced center lines to reduce noise influence on patch boundaries, resulting in a smaller set of robust center lines authentically representing their road patches. Refined center lines are triangulated using constrained Delaunay triangulation (CDT) algorithm to generate a sub-optimal mesh of interconnections among them. The generated triangle edges connecting different center lines are used for spatial analysis of the center lines relations. A subset of the Delaunay tessellation grid contains the Euclidian Minimum Spanning Tree (EMST) that provides an approximation of road network. The approach can be generalized to the multi-criteria MST and multi-criteria shortest path algorithms to integrate other factors important for road network extraction, in addition to proximity relations considered by standard EMST.

  8. An Ad-hoc Satellite Network to Measure Filamentary Current Structures in the Auroral Zone

    Science.gov (United States)

    Nabong, C.; Fritz, T. A.; Semeter, J. L.

    2014-12-01

    An ad-hoc cubesat-based satellite network project known as ANDESITE is under development at Boston University. It aims to develop a dense constellation of easy-to-use, rapidly-deployable low-cost wireless sensor nodes in space. The objectives of the project are threefold: 1) Demonstrate viability of satellite based sensor networks by deploying an 8-node miniature sensor network to study the filamentation of the field aligned currents in the auroral zones of the Earth's magnetosphere. 2) Test the scalability of proposed protocols, including localization techniques, tracking, data aggregation, and routing, for a 3 dimensional wireless sensor network using a "flock" of nodes. 3) Construct a 6U Cube-sat running the Android OS as an integrated constellation manager, data mule and sensor node deplorer. This small network of sensor nodes will resolve current densities at different spatial resolutions in the near-Earth magnetosphere using measurements from magnetometers with 1-nT sensitivities and 0.2 nT/√Hz self-noise. Mapping of these currents will provide new constraints for models of auroral particle acceleration, wave-particle interactions, ionospheric destabilization, and other kinetic processes operating in the low-beta plasma of the near Earth magnetosphere.

  9. Towards an Autonomous Turbidimeter Network for Multi-Mission Ocean Colour Satellite Data Validation Activities

    Science.gov (United States)

    Dogliotti, A. I.; Nechad, B.; Ruddick, K. G.; Gossn, J. I.

    2016-08-01

    Satellite-based optical sensors such as MODIS/Aqua, Sentinel-2, Sentinel-3, Landsat-8, Pléiades, SABIA/Mar, PROBA-V , etc. can be used to map turbidity and suspended particulate matter in coastal, estuarine and inland waters as support for water quality monitoring, sediment transport applications such as dredging and fisheries science. However, data quality is a critical problem and in situ data must be gathered from a wide range of test sites in order to provide validation for the diverse range of conditions that can be encountered all over the world. In this context, a network to validate satellite turbidity products called TURBINET is proposed with the goal to establish a long-term (autonomous) international network of collaboration and data-sharing. Joint measurements of turbidity, reflectance and in-water side/back-scattering have been performed in Belgium and Argentina in 2015. Instrument comparisons showed that comparable values could be retrieved using different sensors and field measurements were used to validate a Pléiades high resolution image (2m). The results presented in this work demonstrate the feasibility and usefulness of setting up a network to validate satellite turbidity products.

  10. Social networking policies in nursing education.

    Science.gov (United States)

    Frazier, Blake; Culley, Joan M; Hein, Laura C; Williams, Amber; Tavakoli, Abbas S

    2014-03-01

    Social networking use has increased exponentially in the past few years. A literature review related to social networking and nursing revealed a research gap between nursing practice and education. Although there was information available on the appropriate use of social networking sites, there was limited research on the use of social networking policies within nursing education. The purpose of this study was to identify current use of social media by faculty and students and a need for policies within nursing education at one institution. A survey was developed and administered to nursing students (n = 273) and nursing faculty (n = 33). Inferential statistics included χ², Fisher exact test, t test, and General Linear Model. Cronbach's α was used to assess internal consistency of social media scales. The χ² result indicates that there were associations with the group and several social media items. t Test results indicate significant differences between student and faculty for average of policies are good (P = .0127), policies and discipline (P = .0315), and policy at the study school (P = .0013). General Linear Model analyses revealed significant differences for "friend" a patient with a bond, unprofessional posts, policy, and nursing with class level. Results showed that students and faculty supported the development of a social networking policy.

  11. Detection of land cover change using an Artificial Neural Network on a time-series of MODIS satellite data

    CSIR Research Space (South Africa)

    Olivier, JC

    2007-11-01

    Full Text Available An Artificial Neural Network (ANN) is proposed to detect human-induced land cover change using a sliding window through a time-series of Moderate Resolution Imaging Spectroradiometer (MODIS) satellite surface reflectance pixel values. Training...

  12. Mapping Efficient Communication Networks in Higher Education.

    Science.gov (United States)

    Lubinescu, E. S.; Prabhu, R. P.; Terheggen, S. L.

    Some perspectives are presented that help explain communication networks in institutions of higher education and the factors that impede or facilitate their efficient functioning. The first theory that informs this exploration is that of K. Wieck (1969), which states that communication can be viewed through the lens of "sensemaking." The…

  13. Social Networking: A Collaborative Open Educational Resource

    Science.gov (United States)

    Toetenel, Lisette

    2014-01-01

    Studies undertaken since the introduction of Web 2.0 have focussed mainly on open educational resources (OERs) such as email, blogging and virtual learning environments. No consistent efforts have been undertaken to study the use of social networking sites as a tool for learning in the second language classroom. This study examined the use of…

  14. Social Networking: A Collaborative Open Educational Resource

    Science.gov (United States)

    Toetenel, Lisette

    2014-01-01

    Studies undertaken since the introduction of Web 2.0 have focussed mainly on open educational resources (OERs) such as email, blogging and virtual learning environments. No consistent efforts have been undertaken to study the use of social networking sites as a tool for learning in the second language classroom. This study examined the use of…

  15. Using Citation Network Analysis in Educational Technology

    Science.gov (United States)

    Cho, Yonjoo; Park, Sunyoung

    2012-01-01

    Previous reviews in the field of Educational Technology (ET) have revealed some publication patterns according to authors, institutions, and affiliations. However, those previous reviews focused only on the rankings of individual authors and institutions, and did not provide qualitative details on relations and networks of scholars and scholarly…

  16. Artificial neural network prediction model for geosynchronous electron fluxes: Dependence on satellite position and particle energy

    Science.gov (United States)

    Shin, Dae-Kyu; Lee, Dae-Young; Kim, Kyung-Chan; Hwang, Junga; Kim, Jaehun

    2016-04-01

    Geosynchronous satellites are often exposed to energetic electrons, the flux of which varies often to a large extent. Since the electrons can cause irreparable damage to the satellites, efforts to develop electron flux prediction models have long been made until recently. In this study, we adopt a neural network scheme to construct a prediction model for the geosynchronous electron flux in a wide energy range (40 keV to >2 MeV) and at a high time resolution (as based on 5 min resolution data). As the model inputs, we take the solar wind variables, geomagnetic indices, and geosynchronous electron fluxes themselves. We also take into account the magnetic local time (MLT) dependence of the geosynchronous electron fluxes. We use the electron data from two geosynchronous satellites, GOES 13 and 15, and apply the same neural network scheme separately to each of the GOES satellite data. We focus on the dependence of prediction capability on satellite's magnetic latitude and MLT as well as particle energy. Our model prediction works less efficiently for magnetic latitudes more away from the equator (thus for GOES 13 than for GOES 15) and for MLTs nearer to midnight than noon. The magnetic latitude dependence is most significant for an intermediate energy range (a few hundreds of keV), and the MLT dependence is largest for the lowest energy (40 keV). We interpret this based on degree of variance in the electron fluxes, which depends on magnetic latitude and MLT at geosynchronous orbit as well as particle energy. We demonstrate how substorms affect the flux variance.

  17. Scalable Video Streaming in Wireless Mesh Networks for Education

    Science.gov (United States)

    Liu, Yan; Wang, Xinheng; Zhao, Liqiang

    2011-01-01

    In this paper, a video streaming system for education based on a wireless mesh network is proposed. A wireless mesh network is a self-organizing, self-managing and reliable intelligent network, which allows educators to deploy a network quickly. Video streaming plays an important role in this system for multimedia data transmission. This new…

  18. Scalable Video Streaming in Wireless Mesh Networks for Education

    Science.gov (United States)

    Liu, Yan; Wang, Xinheng; Zhao, Liqiang

    2011-01-01

    In this paper, a video streaming system for education based on a wireless mesh network is proposed. A wireless mesh network is a self-organizing, self-managing and reliable intelligent network, which allows educators to deploy a network quickly. Video streaming plays an important role in this system for multimedia data transmission. This new…

  19. Neural network-based recognition of whistlers on spectrograms detected by satellite

    Science.gov (United States)

    Conti, Livio

    2016-04-01

    We present a system to automatically recognize and classify the occurrence of whistler waves on spectrograms of electric field measurements performed by satellite. Whistlers - VLF waves generated by lightning, with a specific spectral dispersion relation - can induce precipitation of trapped Van Allen particles and have a role in the chemistry of some atmospheric components (mainly NOx). Moreover, it has also been suggested that the increase of the number of anomalous whistlers (i.e. whistlers with high value of dispersion constant) could be induced by disturbances in the Earth-ionosphere wave-guide, generated by seismo-electromagnetic emissions. On satellite, the recognition of whistlers asks for analyzing high-resolution spectrograms that cannot be downloaded to Earth, due to the limits of data transmission. For this reason, a real time identification and classification must be performed on satellite, by avoiding downloading all the unprocessed data. The procedure that we have developed is based on a Time Delay Neural Network (TDNN). The TDNN, proposed some years ago for speech recognition, can be fruitfully also applied in real-time analysis of electromagnetic spectrograms in order to detect phenomena characterized by a specific shape/signature such as those of the whistler waves. Some studies have been performed by the RNF experiment on board of the DEMETER satellite and our algorithm could be adopted on board of the satellite CSES (China Seismo-Electromagnetic Satellite), launch scheduled by the end of 2016. Moreover, the procedure can be also adopted to automatic analysis of whistlers detected on ground.

  20. The Second Young Engineers' Satellite: Innovative Technology through Education

    Science.gov (United States)

    Fujii, Hironori A.; Kruijff, Michiel; van der Heide, Erik J.; Watanabe, Takeo

    The second Young Engineers' Satellite,YES2, is the longest manmade structure launched in 2007 and is space piggybacked on the Foton-M3 microgravity platform with the objective of a controlled deployment of a 32km tether. This paper introduces the object and the flight results of YES2 and the performance of the satellite is studied in comparison of the simulations and ground tests with respect to the flight results.

  1. The design and networking of dynamic satellite constellations for global mobile communication systems

    Science.gov (United States)

    Cullen, Cionaith J.; Benedicto, Xavier; Tafazolli, Rahim; Evans, Barry

    1993-01-01

    Various design factors for mobile satellite systems, whose aim is to provide worldwide voice and data communications to users with hand-held terminals, are examined. Two network segments are identified - the ground segment (GS) and the space segment (SS) - and are seen to be highly dependent on each other. The overall architecture must therefore be adapted to both of these segments, rather than each being optimized according to its own criteria. Terrestrial networks are grouped and called the terrestrial segment (TS). In the SS, of fundamental importance is the constellation altitude. The effect of the altitude on decisions such as constellation design choice and on network aspects like call handover statistics are fundamental. Orbit resonance is introduced and referred to throughout. It is specifically examined for its useful properties relating to GS/SS connectivities.

  2. Proactive TCP mechanism to improve Handover performance in Mobile Satellite and Terrestrial Networks

    CERN Document Server

    Vinayakray-Jani, Preetida

    2012-01-01

    Emerging standardization of Geo Mobile Radio (GMR-1) for satellite system is having strong resemblance to terrestrial GSM (Global System for Mobile communications) at the upper protocol layers and TCP (Transmission Control Protocol) is one of them. This space segment technology as well as terrestrial technology, is characterized by periodic variations in communication properties and coverage causing the termination of ongoing call as connections of Mobile Nodes (MN) alter stochastically. Although provisions are made to provide efficient communication infrastructure this hybrid space and terrestrial networks must ensure the end-to-end network performance so that MN can move seamlessly among these networks. However from connectivity point of view current TCP performance has not been engineered for mobility events in multi-radio MN. Traditionally, TCP has applied a set of congestion control algorithms (slow-start, congestion avoidance, fast retransmit, fast recovery) to probe the currently available bandwidth on...

  3. A small satellite design for deep space network testing and training

    Science.gov (United States)

    Mcwilliams, Dennis; Slatton, Clint; Norman, Cassidy; Araiza, Joe; Jones, Jason; Tedesco, Mark; Wortman, Michael; Opiela, John; Lett, Pat; Clavenna, Michael

    1993-01-01

    With the continuing exploration of the Solar System and the reemphasis on Earth focused missions, the need for faster data transmission rates has grown. Ka-band could allow a higher data delivery rate over the current X-band, however the adverse effects of the Earth's atmosphere on Ka are as yet unknown. The Deep Space Network and Jet Propulsion Lab have proposed to launch a small satellite that would simultaneously transmit X and Ka signals to test the viability of switching to Ka-band. The Mockingbird Design Team at the University of Texas at Austin applied small satellite design principles to achieve this objective. The Mockingbird design, named BATSAT, incorporates simple, low-cost systems designed for university production and testing. The BATSAT satellite is a 0.64 m diameter, spherical panel led satellite, mounted with solar cells and omni-directional antennae. The antennae configuration negates the need for active attitude control or spin stabilization. The space-frame truss structure was designed for 11 g launch loads while allowing for easy construction and solar-panel mounting. The communication system transmits at 1 mW by carrying the required Ka and X-band transmitters, as well as an S band transmitter used for DSN training. The power system provides the 8.6 W maximum power requirements via silicon solar arrays and nickel-cadmium batteries. The BATSAT satellite will be lofted into an 1163 km, 70 deg orbit by the Pegasus launch system. This orbit fulfills DSN dish slew rate requirements while keeping the satellite out of the heaviest regions of the Van Allen radiation belts. Each of the three DSN stations capable of receiving Ka-band (Goldstone, Canberra, and Madrid) will have an average of 85 minutes of view-time per day over the satellites ten year design life. Mockingbird Designs hopes that its small satellite design will not only be applicable to this specific mission scenario, but that it could easily be modified for instrument capability for

  4. Monitoring Animal Behaviour and Environmental Interactions Using Wireless Sensor Networks, GPS Collars and Satellite Remote Sensing

    Directory of Open Access Journals (Sweden)

    Peter Corke

    2009-05-01

    Full Text Available Remote monitoring of animal behaviour in the environment can assist in managing both the animal and its environmental impact. GPS collars which record animal locations with high temporal frequency allow researchers to monitor both animal behaviour and interactions with the environment. These ground-based sensors can be combined with remotely-sensed satellite images to understand animal-landscape interactions. The key to combining these technologies is communication methods such as wireless sensor networks (WSNs. We explore this concept using a case-study from an extensive cattle enterprise in northern Australia and demonstrate the potential for combining GPS collars and satellite images in a WSN to monitor behavioural preferences and social behaviour of cattle.

  5. Networks systems and operations. [wideband communication techniques for data links with satellites

    Science.gov (United States)

    1975-01-01

    The application of wideband communication techniques for data links with satellites is discussed. A diagram of the demand assigned voice communications system is provided. The development of prototype integrated spacecraft paramps at S- and C-bands is described and the performance of space-qualified paramps is tabulated. The characteristics of a dual parabolic cylinder monopulse zoom antenna for use with the tracking and data relay satellite system (TDRSS) are analyzed. The development of a universally applicable transponder at S-band is reported. A block diagram of the major subassemblies of the S-band transponder is included. The technology aspects of network timing and synchronization of communication systems are to show the use of the Omega navigation system. The telemetry data compression system used during the Skylab program is evaluated.

  6. Communication Media and Educational Technology: An Overview and Assessment with Reference to Communication Satellites.

    Science.gov (United States)

    Ohlman, Herbert

    In this survey and analysis of the present state and future trends of communication media and educational technology, particular emphasis is placed on the potential uses of communication satellites and the substitution of electronic transmission for physical distribution of educational materials. The author analyzes in detail the characteristics…

  7. Policy Issues in Planning for Distance Education Using a Domestic Communication Satellite.

    Science.gov (United States)

    Gough, J. Eric; And Others

    1981-01-01

    Considers important political and practical issues within the field of distance education raised by the decision for Australia to have its own communications satellite. The experiences of other countries are examined and the importance of communication policy and planning, educational needs-assessment, cost-effectiveness studies, resource…

  8. Application of Communications Satellite to Educational Development; An Overview of the Washington University Program.

    Science.gov (United States)

    Morgan, Robert P.; And Others

    Selected aspects and results of an interdisciplinary research and education program to examine the potential and problems associated with the use of communication satellites to help meet educational needs in the United States are summarized. The progress of the program to date in four major areas is described: needs analysis, communications…

  9. Education and outreach using the falcon telescope network

    Science.gov (United States)

    Gresham, Kimberlee C.; Palma, Christopher; Polsgrove, Daniel E.; Chun, Francis K.; Della-Rose, Devin J.; Tippets, Roger D.

    2016-12-01

    The Falcon Telescope Network (FTN) is a global network of small aperture telescopes developed by the Center for Space Situational Awareness Research in the Department of Physics at the United States Air Force Academy (USAFA). Consisting of commercially available equipment, the FTN is a collaborative effort between USAFA and other educational institutions ranging from two- and four-year colleges to major research universities. USAFA provides the equipment (e.g. telescope, mount, camera, filter wheel, dome, weather station, computers and storage devices) while the educational partners provide the building and infrastructure to support an observatory. The user base includes USAFA along with K-12 and higher education faculty and students. The diversity of the users implies a wide variety of observing interests, and thus the FTN collects images on diverse objects, including satellites, galactic and extragalactic objects, and objects popular for education and public outreach. The raw imagery, all in the public domain, will be accessible to FTN partners and will be archived at USAFA. Currently, there are five Falcon telescopes installed, two in Colorado and one each in Pennsylvania, Chile, and Australia. These five telescopes are in various stages of operational capability but all are remotely operable via a remote desktop application. The FTN team has conducted STEM First Light Projects for three of the U.S. observatories, soliciting proposals from middle and high school students and teachers that suggest and then become what is observed as official STEM first-light objects. Students and teachers learn how to write and submit a proposal as well as how telescopes operate and take data, while university-level students at the U.S. Air Force Academy and The Pennsylvania State University learn how to evaluate proposals and provide feedback to the middle and high school students and teachers. In this paper, we present the current status of the FTN, details of and lessons

  10. OPEN LEADERSHIP AND SOCIAL NETWORKS IN EDUCATION

    Directory of Open Access Journals (Sweden)

    Murat Polat

    2014-04-01

    Full Text Available The 21st century, is a candidate to take its place in the pages of history as a golden age lived in the most prolific period of computer and internet technology. From the beginning of this century, all types and all fields that appear on the computer-based technology has changed the perspective of the opportunities and possibilities for the future of humanity. Technologies, especially Web 2.0 and other social networking (facebook, twitter, etc. facilities provided by almost every area of life is quite remarkable. Open leadership, educational organizations to facilitate this process, the property is considered to be an administrator. Hence, the purpose of this research is to explain the features and concepts of open leadership and social networks in education. The domestic and foreign publications on the subject were reviewed and suggestions were made in accordance with available data.

  11. Design for the Assessment and Policy Analysis of the Education Satellite Communications Demonstration. Phase 2 Final Report.

    Science.gov (United States)

    Syracuse Univ. Research Corp., NY. Educational Policy Research Center.

    The overall goal of the Education Satellite Communications Demonstration is to design a framework for the analysis of the potential utility of satellites to education in this country. Within this framework, Phase 2 sought to identify research which would be clearly related to educational goals that might be worthy of attainment. The entire…

  12. Magnetic resonance imaging research in sub-Saharan Africa: challenges and satellite-based networking implementation.

    Science.gov (United States)

    Latourette, Matthew T; Siebert, James E; Barto, Robert J; Marable, Kenneth L; Muyepa, Anthony; Hammond, Colleen A; Potchen, Michael J; Kampondeni, Samuel D; Taylor, Terrie E

    2011-08-01

    As part of an NIH-funded study of malaria pathogenesis, a magnetic resonance (MR) imaging research facility was established in Blantyre, Malaŵi to enhance the clinical characterization of pediatric patients with cerebral malaria through application of neurological MR methods. The research program requires daily transmission of MR studies to Michigan State University (MSU) for clinical research interpretation and quantitative post-processing. An intercontinental satellite-based network was implemented for transmission of MR image data in Digital Imaging and Communications in Medicine (DICOM) format, research data collection, project communications, and remote systems administration. Satellite Internet service costs limited the bandwidth to symmetrical 384 kbit/s. DICOM routers deployed at both the Malaŵi MRI facility and MSU manage the end-to-end encrypted compressed data transmission. Network performance between DICOM routers was measured while transmitting both mixed clinical MR studies and synthetic studies. Effective network latency averaged 715 ms. Within a mix of clinical MR studies, the average transmission time for a 256 × 256 image was ~2.25 and ~6.25 s for a 512 × 512 image. Using synthetic studies of 1,000 duplicate images, the interquartile range for 256 × 256 images was [2.30, 2.36] s and [5.94, 6.05] s for 512 × 512 images. Transmission of clinical MRI studies between the DICOM routers averaged 9.35 images per minute, representing an effective channel utilization of ~137% of the 384-kbit/s satellite service as computed using uncompressed image file sizes (including the effects of image compression, protocol overhead, channel latency, etc.). Power unreliability was the primary cause of interrupted operations in the first year, including an outage exceeding 10 days.

  13. Trans-Pacific HDR Satellite Communications Experiment Phase-2 Project Plan and Experimental Network

    Science.gov (United States)

    Hsu, Eddie; Kadowaki, Naoto; Yoshimura, Naoko; Takahashi, Takashi; Yoshikawa, Makoto; Bergman, Larry; Bhasin, Kul

    2000-01-01

    The trans-Pacific high data rate (TP-HDR) satellite communications experiment was proposed at the Japan-U.S. Cooperation in Space (JUCS) Program Workshop held in Hawaii in 1993 and remote high definition video post-production was demonstrated as the first phase trial. ATM-based 45 Mbps trans-Pacific link was established in the first phase, and the following experiments with 155 Mbps was planned as the phase 2. This paper describes the experimental network configuration and project plan of TP-HDR experiment phase 2. Additional information is provided in the original.

  14. Fast Road Network Extraction in Satellite Images Using Mathematical Morphology and Markov Random Fields

    Directory of Open Access Journals (Sweden)

    Thierry Géraud

    2004-12-01

    Full Text Available We present a fast method for road network extraction in satellite images. It can be seen as a transposition of the segmentation scheme “watershed transform + region adjacency graph + Markov random fields” to the extraction of curvilinear objects. Many road extractors which are composed of two stages can be found in the literature. The first one acts like a filter that can decide from a local analysis, at every image point, if there is a road or not. The second stage aims at obtaining the road network structure. In the method we propose to rely on a “potential” image, that is, unstructured image data that can be derived from any road extractor filter. In such a potential image, the value assigned to a point is a measure of its likelihood to be located in the middle of a road. A filtering step applied on the potential image relies on the area closing operator followed by the watershed transform to obtain a connected line which encloses the road network. Then a graph describing adjacency relationships between watershed lines is built. Defining Markov random fields upon this graph, associated with an energetic model of road networks, leads to the expression of road network extraction as a global energy minimization problem. This method can easily be adapted to other image processing fields, where the recognition of curvilinear structures is involved.

  15. Comparision of Clustering Algorithms usingNeural Network Classifier for Satellite Image Classification

    Directory of Open Access Journals (Sweden)

    S.Praveena

    2015-06-01

    Full Text Available This paper presents a hybrid clustering algorithm and feed-forward neural network classifier for land-cover mapping of trees, shade, building and road. It starts with the single step preprocessing procedure to make the image suitable for segmentation. The pre-processed image is segmented using the hybrid genetic-Artificial Bee Colony(ABC algorithm that is developed by hybridizing the ABC and FCM to obtain the effective segmentation in satellite image and classified using neural network . The performance of the proposed hybrid algorithm is compared with the algorithms like, k-means, Fuzzy C means(FCM, Moving K-means, Artificial Bee Colony(ABC algorithm, ABC-GA algorithm, Moving KFCM and KFCM algorithm.

  16. Privacy Issues of a National Research and Education Network.

    Science.gov (United States)

    Katz, James E.; Graveman, Richard F.

    1991-01-01

    Discussion of the right to privacy of communications focuses on privacy expectations within a National Research and Education Network (NREN). Highlights include privacy needs in scientific and education communications; academic and research networks; network security and privacy concerns; protection strategies; and consequences of privacy…

  17. Cost Analysis of Algorithm Based Billboard Manger Based Handover Method in LEO satellite Networks

    Directory of Open Access Journals (Sweden)

    Suman Kumar Sikdar

    2012-12-01

    Full Text Available Now-a-days LEO satellites have an important role in global communication system. They have some advantages like low power requirement and low end-to-end delay, more efficient frequency spectrum utilization between satellites and spot beams over GEO and MEO. So in future they can be used as a replacement of modern terrestrial wireless networks. But the handover occurrence is more due to the speed of the LEOs. Different protocol has been proposed for a successful handover among which BMBHO is more efficient. But it had a problem during the selection of the mobile node during handover. In our previous work we have proposed an algorithm so that the connection can be established easily with the appropriate satellite. In this paper we will evaluate the mobility management cost of Algorithm based Billboard Manager Based Handover method (BMBHO. A simulation result shows that the cost is lower than the cost of Mobile IP of SeaHO-LEO and PatHOLEO

  18. Minimum Number of Observation Points for LEO Satellite Orbit Estimation by OWL Network

    Science.gov (United States)

    Park, Maru; Jo, Jung Hyun; Cho, Sungki; Choi, Jin; Kim, Chun-Hwey; Park, Jang-Hyun; Yim, Hong-Suh; Choi, Young-Jun; Moon, Hong-Kyu; Bae, Young-Ho; Park, Sun-Youp; Kim, Ji-Hye; Roh, Dong-Goo; Jang, Hyun-Jung; Park, Young-Sik; Jeong, Min-Ji

    2015-12-01

    By using the Optical Wide-field Patrol (OWL) network developed by the Korea Astronomy and Space Science Institute (KASI) we generated the right ascension and declination angle data from optical observation of Low Earth Orbit (LEO) satellites. We performed an analysis to verify the optimum number of observations needed per arc for successful estimation of orbit. The currently functioning OWL observatories are located in Daejeon (South Korea), Songino (Mongolia), and Oukaïmeden (Morocco). The Daejeon Observatory is functioning as a test bed. In this study, the observed targets were Gravity Probe B, COSMOS 1455, COSMOS 1726, COSMOS 2428, SEASAT 1, ATV-5, and CryoSat-2 (all in LEO). These satellites were observed from the test bed and the Songino Observatory of the OWL network during 21 nights in 2014 and 2015. After we estimated the orbit from systematically selected sets of observation points (20, 50, 100, and 150) for each pass, we compared the difference between the orbit estimates for each case, and the Two Line Element set (TLE) from the Joint Space Operation Center (JSpOC). Then, we determined the average of the difference and selected the optimal observation points by comparing the average values.

  19. An Optical Sensor Network for Vegetation Phenology Monitoring and Satellite Data Calibration

    Directory of Open Access Journals (Sweden)

    Michal Heliasz

    2011-08-01

    Full Text Available We present a network of sites across Fennoscandia for optical sampling of vegetation properties relevant for phenology monitoring and satellite data calibration. The network currently consists of five sites, distributed along an N-S gradient through Sweden and Finland. Two sites are located in coniferous forests, one in a deciduous forest, and two on peatland. The instrumentation consists of dual-beam sensors measuring incoming and reflected red, green, NIR, and PAR fluxes at 10-min intervals, year-round. The sensors are mounted on separate masts or in flux towers in order to capture radiation reflected from within the flux footprint of current eddy covariance measurements. Our computations and model simulations demonstrate the validity of using off-nadir sampling, and we show the results from the first year of measurement. NDVI is computed and compared to that of the MODIS instrument on-board Aqua and Terra satellite platforms. PAR fluxes are partitioned into reflected and absorbed components for the ground and canopy. The measurements demonstrate that the instrumentation provides detailed information about the vegetation phenology and variations in reflectance due to snow cover variations and vegetation development. Valuable information about PAR absorption of ground and canopy is obtained that may be linked to vegetation productivity.

  20. An optical sensor network for vegetation phenology monitoring and satellite data calibration.

    Science.gov (United States)

    Eklundh, Lars; Jin, Hongxiao; Schubert, Per; Guzinski, Radoslaw; Heliasz, Michal

    2011-01-01

    We present a network of sites across Fennoscandia for optical sampling of vegetation properties relevant for phenology monitoring and satellite data calibration. The network currently consists of five sites, distributed along an N-S gradient through Sweden and Finland. Two sites are located in coniferous forests, one in a deciduous forest, and two on peatland. The instrumentation consists of dual-beam sensors measuring incoming and reflected red, green, NIR, and PAR fluxes at 10-min intervals, year-round. The sensors are mounted on separate masts or in flux towers in order to capture radiation reflected from within the flux footprint of current eddy covariance measurements. Our computations and model simulations demonstrate the validity of using off-nadir sampling, and we show the results from the first year of measurement. NDVI is computed and compared to that of the MODIS instrument on-board Aqua and Terra satellite platforms. PAR fluxes are partitioned into reflected and absorbed components for the ground and canopy. The measurements demonstrate that the instrumentation provides detailed information about the vegetation phenology and variations in reflectance due to snow cover variations and vegetation development. Valuable information about PAR absorption of ground and canopy is obtained that may be linked to vegetation productivity.

  1. Modulation Classification of Satellite Communication Signals Using Cumulants and Neural Networks

    Science.gov (United States)

    Smith, Aaron; Evans, Michael; Downey, Joseph

    2017-01-01

    National Aeronautics and Space Administration (NASA)'s future communication architecture is evaluating cognitive technologies and increased system intelligence. These technologies are expected to reduce the operational complexity of the network, increase science data return, and reduce interference to self and others. In order to increase situational awareness, signal classification algorithms could be applied to identify users and distinguish sources of interference. A significant amount of previous work has been done in the area of automatic signal classification for military and commercial applications. As a preliminary step, we seek to develop a system with the ability to discern signals typically encountered in satellite communication. Proposed is an automatic modulation classifier which utilizes higher order statistics (cumulants) and an estimate of the signal-to-noise ratio. These features are extracted from baseband symbols and then processed by a neural network for classification. The modulation types considered are phase-shift keying (PSK), amplitude and phase-shift keying (APSK),and quadrature amplitude modulation (QAM). Physical layer properties specific to the Digital Video Broadcasting - Satellite- Second Generation (DVB-S2) standard, such as pilots and variable ring ratios, are also considered. This paper will provide simulation results of a candidate modulation classifier, and performance will be evaluated over a range of signal-to-noise ratios, frequency offsets, and nonlinear amplifier distortions.

  2. A system for the simulation and evaluation of satellite communication networks

    Science.gov (United States)

    Bagwell, J. W.

    1984-01-01

    With the emergence of a new era in satellite communications, brought about by NASA's thrust into the Ka band with multibeam and onboard processing technologies, new and innovative techniques for evaluating these concepts and systems are required. To this end, NASA, in conjunction with its extensive program for advanced communications technology development, has undertaken to develop a concept for the simulation and evaluation of a complete communications network. Incorporated in this network will be proof-of-concept models of the latest technologies proposed for future satellite communications systems. These include low noise receivers, matrix switches, baseband processors, and solid state and tube type high power amplifiers. To accomplish this, numerous supporting technologies must be added to those aforementioned proof-of-concept models. These include controllers for synchronization, order wire, resource allocation, gain compensation, signal leveling, power augmentation, and rain fade and range delay simulation. Taken together, these will be assembled to comprise a system capable of addressing numerous design and performance questions. The simulation and evaluation system, as planned, will be modular in design and implementation, capable of modification and updating to track and evaluate a continuum of emerging concepts and technologies. Previously announced in STAR as N84-13400

  3. Quantum communication for satellite-to-ground networks with partially entangled states

    Science.gov (United States)

    Chen, Na; Quan, Dong-Xiao; Pei, Chang-Xing; Yang-Hong

    2015-02-01

    To realize practical wide-area quantum communication, a satellite-to-ground network with partially entangled states is developed in this paper. For efficiency and security reasons, the existing method of quantum communication in distributed wireless quantum networks with partially entangled states cannot be applied directly to the proposed quantum network. Based on this point, an efficient and secure quantum communication scheme with partially entangled states is presented. In our scheme, the source node performs teleportation only after an end-to-end entangled state has been established by entanglement swapping with partially entangled states. Thus, the security of quantum communication is guaranteed. The destination node recovers the transmitted quantum bit with the help of an auxiliary quantum bit and specially defined unitary matrices. Detailed calculations and simulation analyses show that the probability of successfully transferring a quantum bit in the presented scheme is high. In addition, the auxiliary quantum bit provides a heralded mechanism for successful communication. Based on the critical components that are presented in this article an efficient, secure, and practical wide-area quantum communication can be achieved. Project supported by the National Natural Science Foundation of China (Grant Nos. 61072067 and 61372076), the 111 Project (Grant No. B08038), the Fund from the State Key Laboratory of Integrated Services Networks (Grant No. ISN 1001004), and the Fundamental Research Funds for the Central Universities (Grant Nos. K5051301059 and K5051201021).

  4. Resilient Sensor Networks with Spatiotemporal Interpolation of Missing Sensors: An Example of Space Weather Forecasting by Multiple Satellites.

    Science.gov (United States)

    Tokumitsu, Masahiro; Hasegawa, Keisuke; Ishida, Yoshiteru

    2016-04-15

    This paper attempts to construct a resilient sensor network model with an example of space weather forecasting. The proposed model is based on a dynamic relational network. Space weather forecasting is vital for a satellite operation because an operational team needs to make a decision for providing its satellite service. The proposed model is resilient to failures of sensors or missing data due to the satellite operation. In the proposed model, the missing data of a sensor is interpolated by other sensors associated. This paper demonstrates two examples of space weather forecasting that involves the missing observations in some test cases. In these examples, the sensor network for space weather forecasting continues a diagnosis by replacing faulted sensors with virtual ones. The demonstrations showed that the proposed model is resilient against sensor failures due to suspension of hardware failures or technical reasons.

  5. Networking in medical education: Creating and connecting

    Directory of Open Access Journals (Sweden)

    Supe Avinash

    2008-03-01

    Full Text Available Social networking is being increasingly used as a tool of choice for communications and collaborations in business and higher education. Learning and practice become inseparable when professionals work in communities of practice that create interpersonal bonds and promote collective learning. Individual learning that arises from the critical reconstruction of practice, in the presence of peers and other health professionals, enhances a physician′s capability of clinical judgment and evidence-based practice. As such, it would be wise for medical schools, whose responsibility it is to prepare students to make a transition to adult life with the skills they need to succeed in both arenas, to reckon with it.

  6. The interactive use of networking multimedia--innovative education resource for professionals and patients.

    Science.gov (United States)

    Matthies, H K; Walter, G F; Brandis, A; Stan, A C; Ammann, A; von Jan, U; Porth, A J

    1999-01-01

    The combination of new and rapidly developing interactive multimedia computers and applications with electronic networks will require a restructuring of our traditional approach to strategic planning and organizational structure. Worldwide telecommunication networks (using satellites, cable) are now facilitating the global pooling of healthcare information and medical knowledge independent of location. The development of multimedia information and communication systems demands cooperative working teams of authors, who are able to master several areas of medical knowledge as well as the presentation of these in different multimedia forms. The assemblage of telematics and services offers a base for multimedia applications, for example teleteaching, telelearning, telepublishing, teleconsulting, teleconferencing, telemedicine etc. The expansion of the internet will also lead to the formation of interdisciplinary "Global Education Networks". The theory and practice of education are undergoing dramatic changes. Lifelong learning and adaptation of medical practice to new knowledge and new techniques will be even more important in the future.

  7. Core-based Shared Tree Multicast Routing Algorithms for LEO Satellite IP Networks

    Institute of Scientific and Technical Information of China (English)

    Cheng Lianzhen; Zhang Jun; Liu Kai

    2007-01-01

    A new core-based shared tree algorithm, viz core-cluster combination-based shared tree (CCST) algorithm and the weighted version (i.e. w-CCST algorithm) are proposed in order to resolve the channel resources waste problem in typical source-based multicast routing algorithms in low earth orbit (LEO) satellite IP networks. The CCST algorithm includes the dynamic approximate center (DAC)core selection method and the core-cluster combination multicast route construction scheme. Without complicated onboard computation,the DAC method is uniquely developed for highly dynamic networks of periodical and regular movement. The core-cluster combination method takes core node as the initial core-cluster, and expands it stepwise to construct an entire multicast tree at the lowest tree cost by a shortest path scheme between the newly-generated core-cluster and surplus group members, which results in great bandwidth utilization.Moreover, the w-CCST algorithm is able to strike a balance between performance of tree cost and that of end-to-end propagation delay by adjusting the weighted factor to meet strict end-to-end delay requirements of some real-time multicast services at the expense of a slight increase in tree cost. Finally, performance comparison is conducted between the proposed algorithms and typical algorithms in LEO satellite IP networks. Simulation results show that the CCST algorithm significantly decreases the average tree cost against to the others, and also the average end-to-end propagation delay of w-CCST algorithm is lower than that of the CCST algorithm.

  8. BUILDING A NETWORK FOR NEUTRON SCATTERING EDUCATION

    Energy Technology Data Exchange (ETDEWEB)

    Pynn, Roger [ORNL; Baker, Shenda Mary [ORNL; Louca, Despo A [ORNL; McGreevy, Robert L [ORNL; Ekkebus, Allen E [ORNL; Kszos, Lynn A [ORNL; Anderson, Ian S [ORNL

    2008-10-01

    In a concerted effort supported by the National Science Foundation, the Department of Commerce, and the Department of Energy, the United States is rebuilding its leadership in neutron scattering capability through a significant investment in U.S. neutron scattering user facilities and related instrumentation. These unique facilities provide opportunities in neutron scattering to a broad community of researchers from academic institutions, federal laboratories, and industry. However, neutron scattering is often considered to be a tool for 'experts only' and in order for the U.S. research community to take full advantage of these new and powerful tools, a comprehensive education and outreach program must be developed. The workshop described below is the first step in developing a national program that takes full advantage of modern education methods and leverages the existing educational capacity at universities and national facilities. During March 27-28, 2008, a workshop entitled 'Building a Network for Neutron Scattering Education' was held in Washington, D.C. The goal of the workshop was to define and design a roadmap for a comprehensive neutron scattering education program in the United States. Successful implementation of the roadmap will maximize the national intellectual capital in neutron sciences and will increase the sophistication of research questions addressed by neutron scattering at the nation's forefront facilities. (See Appendix A for the list of attendees, Appendix B for the workshop agenda, Appendix C for a list of references. Appendix D contains the results of a survey given at the workshop; Appendix E contains summaries of the contributed talks.) The workshop brought together U.S. academicians, representatives from neutron sources, scientists who have developed nontraditional educational programs, educational specialists, and managers from government agencies to create a national structure for providing ongoing neutron

  9. A New Damage Assessment Method by Means of Neural Network and Multi-Sensor Satellite Data

    Directory of Open Access Journals (Sweden)

    Alessandro Piscini

    2017-08-01

    Full Text Available Artificial Neural Network (ANN is a valuable and well-established inversion technique for the estimation of geophysical parameters from satellite images. After training, ANNs are able to generate very fast products for several types of applications. Satellite remote sensing is an efficient way to detect and map strong earthquake damage for contributing to post-disaster activities during emergency phases. This work aims at presenting an application of the ANN inversion technique addressed to the evaluation of building collapse ratio (CR, defined as the number of collapsed buildings with respect to the total number of buildings in a city block, by employing optical and SAR satellite data. This is done in order to directly relate changes in images with damage that has occurred during strong earthquakes. Furthermore, once they have been trained, neural networks can be used rapidly at application stage. The goal was to obtain a general tool suitable for re-use in different scenarios. An ANN has been implemented in order to emulate a regression model and to estimate the CR as a continuous function. The adopted ANN has been trained using some features obtained from optical and Synthetic Aperture Radar (SAR images, as inputs, and the corresponding values of collapse ratio obtained from the survey of the 2010 M7 Haiti Earthquake, i.e., as target output. As regards the optical data, we selected three change parameters: the Normalized Difference Index (NDI, the Kullback–Leibler divergence (KLD, and Mutual Information (MI. Concerning the SAR images, the Intensity Correlation Difference (ICD and the KLD parameters have been considered. Exploiting an object-oriented approach, a segmentation of the study area into several regions has been performed. In particular, damage maps have been generated by considering a set of polygons (in which satellite parameters have been calculated extracted from the open source Open Street Map (OSM geo-database. The trained

  10. Educational Applications of Communications Satellites in Canada. New Technologies in Canadian Education Series. Paper 12.

    Science.gov (United States)

    Richmond, J. Murray

    Canada has explored the use of satellites as a means to provide information and communications services to geographically isolated populations since 1962. Between 1972 and 1984, five series of satellites known as Anik A, B, C, and D and Hermes were launched. Each satellite provided expanded communications services, and each led to research and…

  11. Communication Satellite Technology as a Potential Comprehensive Delivery System for Correctional Institution Education and Training Programs

    Science.gov (United States)

    Polcyn, Kenneth A.

    1977-01-01

    By pooling resources and using communication satellites to access quality regional or national programs and personnel, institutions may be able to determine inmate aptitudes and career options, receive career counselling for inmates based on job trends, access educational and vocational training programs that match the inmates' capabilities and…

  12. Combined Release and Radiation Effects Satellite (CRRES) Experiment: Educational planning and coordination

    Science.gov (United States)

    Vaughan, William W.; Alzmann, Melanie

    1991-01-01

    The efforts conducted to provide educational planning and development support for the Combined Release and Radiation Satellite (CRRES) Experiment are summarized. Activities regarding the scientific working group and workshop development are presented including the preparation of descriptive information on the CRRES Project.

  13. Communication Satellite Technology as a Potential Comprehensive Delivery System for Correctional Institution Education and Training Programs

    Science.gov (United States)

    Polcyn, Kenneth A.

    1977-01-01

    By pooling resources and using communication satellites to access quality regional or national programs and personnel, institutions may be able to determine inmate aptitudes and career options, receive career counselling for inmates based on job trends, access educational and vocational training programs that match the inmates' capabilities and…

  14. Application of Communications Satellites to Educational Development. Final Technical Report, September 1, 1969-August 31, 1975.

    Science.gov (United States)

    Morgan, Robert P.

    Research is summarized in a brief final report built around a four-section bibliography. The first section lists periodic progress reports and articles which provide an overview of the program, including articles which pertain primarily to educational rather than technical aspects of satellite utilization. Theses carried out in the fields of…

  15. EDUCATIONAL NETWORKING: HUMAN VIEW TO CYBER DEFENSE

    Directory of Open Access Journals (Sweden)

    Oleksandr Yu. Burov

    2016-05-01

    Full Text Available Networks play more and more important role for human life and activity, both in critical occupations (aviation, power industry, military missions etc., and in everyday life (home computers, education, leisure. Interaction between human and other elements of human-machine system have changed, because they coincide in the information habitat. Human-system integration has reached new level of defense needs. The paper will introduce features of information society in respect of a human and corresponding changes in HF/E: (1 information becomes a tool, goal, mean and environment of a human activity, (2 it becomes a part of the human nature and this makes him/her unprotected, (3 human psycho-physiological status becomes not only a basis of effective performance, but an object of control and support, and means of a human security and safety should be a part of information habitat, (4 networking environment becomes an independent actor in a human activity. Accompanying cyber-security challenges and tasks are discussed, as well as types of networking threats and Human View regarding the cyber security challenges.

  16. SOCIAL NETWORKS AS THE ENVIRONMENT EDUCATION

    Directory of Open Access Journals (Sweden)

    Wojsław Czupryński

    2016-12-01

    Full Text Available The emergence of the global Internet has changed the way the entire human population communicates. The internet has become a platform, where human societies build their lives, and traditional communication over the last few years has been replaced by social networks. Today, social networks are the subject of many debates concerning their advantages, disadvantages and the ideas of what they bring to the future. Portals are not only the way of communication, fun, an idea to spend free time, but also source of social and humanistic knowledge too. Against that, social media could be a huge risk for those who use them. The assigned job above discusses about the topic the detrimental effect what the social networks bring. A series of deviant behaviors caused by use of the portal is also presented in this report. Often they become a dysfunctional generator of actions that manifest themselves among the youth. Consequently, there was a need to take action to stop the growth of this phenomenon among young people. First of all the primary activities at this level are prevention and education in the family.

  17. Inter-Agency Network for Education in Emergencies

    Directory of Open Access Journals (Sweden)

    Allison Anderson

    2006-07-01

    Full Text Available In December 2004, the Inter-Agency Network for Educationin Emergencies (INEE launched the first global tool todefine a minimum level of educational quality and helpensure the right to education for people affected by crises.

  18. Neural Network Change Detection Model for Satellite Images Using Textural and Spectral Characteristics

    Directory of Open Access Journals (Sweden)

    A. K. Helmy

    2010-01-01

    Full Text Available Problem statement: Change detection is the process of identifying difference of the state of an object or phenomena by observing it at different time. Essentially, it involves the ability to quantify temporal effects using multi-temporal data sets. Information about change is necessary for evaluating land cover and the management of natural resources. Approach: A neural network model based on both spectral and textural analysis is developed. Change detection system in this study is presented using modified version of back-propagation-training algorithm with dynamic learning rate and momentum. Through proposed model, the two images at different dates are fed into the input layer of neural network, in addition with Variance, Skewness and Eculedian for each image that represent different texture measure. This leads to better discrimination process. Results: The results showed that the trained network with texture measures achieve 23% higher accuracy than that without textural parameters. Conclusion: Adding textural parameters of satellite images through training phase increases the efficiently of change detection process also, it provides adequate information about the type of changes. It also found, when using dynamic momentum and learning rate, time and effort needed to select their appropriate value is reduced.

  19. A FD/DAMA network architecture for the first generation land mobile satellite services

    Science.gov (United States)

    Yan, T.-Y.; Wang, C.; Cheng, U.; Dessouky, K.; Rafferty, W.

    1989-01-01

    A frequency division/demand assigned multiple access (FD/DAMA) network architecture for the first-generation land mobile satellite services is presented. Rationales and technical approaches are described. In this architecture, each mobile subscriber must follow a channel access protocol to make a service request to the network management center before transmission for either open-end or closed-end services. Open-end service requests will be processed on a blocked call cleared basis, while closed-end requests will be processed on a first-come-first-served basis. Two channel access protocols are investigated, namely, a recently proposed multiple channel collision resolution scheme which provides a significantly higher useful throughput, and the traditional slotted Aloha scheme. The number of channels allocated for either open-end or closed-end services can be adaptively changed according to aggregated traffic requests. Both theoretical and simulation results are presented. Theoretical results have been verified by simulation on the JPL network testbed.

  20. Quantum communication for satellite-to-ground networks with partially entangled states

    Institute of Scientific and Technical Information of China (English)

    陈娜; 权东晓; 裴昌幸; 杨宏

    2015-01-01

    To realize practical wide-area quantum communication, a satellite-to-ground network with partially entangled states is developed in this paper. For efficiency and security reasons, the existing method of quantum communication in distributed wireless quantum networks with partially entangled states cannot be applied directly to the proposed quantum network. Based on this point, an efficient and secure quantum communication scheme with partially entangled states is presented. In our scheme, the source node performs teleportation only after an end-to-end entangled state has been established by entanglement swapping with partially entangled states. Thus, security of quantum communication is guaranteed. The destination node recovers the transmitted quantum bit with the help of auxiliary quantum bit and specially defined unitary matrices. Detailed calculations and simulation analyses show that in the presented scheme, the probability of successfully transferring a quantum bit is high. In addition, the auxiliary quantum bit provides a heralded mechanism for successful communication. Based on these critical components presented in this article, an efficient, secure, and practical wide-area quantum communication can be achieved.

  1. Qualitative exploration of centralities in municipal science education networks

    DEFF Research Database (Denmark)

    von der Fehr, Ane; Sølberg, Jan

    2016-01-01

    This article examines the social nature of educational change by conducting a social network analysis of social networks involving stakeholders of science education from teachers to political stakeholders. Social networks that comprise supportive structures for development of science education...... are diverse and in order to understand how municipal stakeholders may support such development, we explored four different municipal science education networks (MSE networks) using three different measures of centrality. The centrality measures differed in terms of what kind of stakeholder functions...... they expressed as well and thereby how they contributed to social capital in the MSE networks. We found that the central stakeholders comprised a small core of key people that always included MSE coordinators. These results imply that few central people in MSE networks play pivotal roles in development...

  2. Unlicensed Spectrum Sharing Game Between LEO Satellites and Terrestrial Cognitive Radio Networks

    Institute of Scientific and Technical Information of China (English)

    XIE Zhuochen; MA Lu; LIANG Xuwen

    2012-01-01

    By cognitive radio,the low Earth orbit (LEO) satellites may prefer to operate in the unlicensed spectrum which is open to all the users,and compete for the limited resources with terrestrial cognitive radio networks (CRNs).The competition can be regarded as a game and analyzed with game theory.This particular unlicensed spectrum sharing problem is modeled here,and the special properties of “spatially-distinguished-interference” and the short period of the interactions between satellites and terrestrial CRNs are explored.Then,the problem is formulated as a “partially-blind” finitely repeated prisoner's dilemma by game theory.Finally,we begin with two promising spectrum sharing schemes,which can be used to enforce the frequency reuse among the remotely located terrestrial CRN players as well as to overcome the observation noise.By analysis and comparison,it is proposed that the novel refreshing-contrite-tit-for-tat (R-CTFT) is the optimal spectrum sharing scheme.Simulation results verify that it can be used to utilize the spectrum most efficiently.

  3. A Topology Control Strategy with Reliability Assurance for Satellite Cluster Networks in Earth Observation

    Science.gov (United States)

    Chen, Qing; Zhang, Jinxiu; Hu, Ze

    2017-01-01

    This article investigates the dynamic topology control problem of satellite cluster networks (SCNs) in Earth observation (EO) missions by applying a novel metric of stability for inter-satellite links (ISLs). The properties of the periodicity and predictability of satellites’ relative position are involved in the link cost metric which is to give a selection criterion for choosing the most reliable data routing paths. Also, a cooperative work model with reliability is proposed for the situation of emergency EO missions. Based on the link cost metric and the proposed reliability model, a reliability assurance topology control algorithm and its corresponding dynamic topology control (RAT) strategy are established to maximize the stability of data transmission in the SCNs. The SCNs scenario is tested through some numeric simulations of the topology stability of average topology lifetime and average packet loss rate. Simulation results show that the proposed reliable strategy applied in SCNs significantly improves the data transmission performance and prolongs the average topology lifetime. PMID:28241474

  4. Adaptive Predistortions Based on Neural Networks Associated with Levenberg-Marquardt Algorithm for Satellite Down Links

    Directory of Open Access Journals (Sweden)

    Roviras Daniel

    2008-01-01

    Full Text Available Abstract This paper presents adaptive predistortion techniques based on a feed-forward neural network (NN to linearize power amplifiers such as those used in satellite communications. Indeed, it presents the suitable NN structures which give the best performances for three satellite down links. The first link is a stationary memoryless travelling wave tube amplifier (TWTA, the second one is a nonstationary memoryless TWT amplifier while the third is an amplifier with memory modeled by a memoryless amplifier followed by a linear filter. Equally important, it puts forward the studies concerning the application of different NN training algorithms in order to determine the most prefermant for adaptive predistortions. This comparison examined through computer simulation for 64 carriers and 16-QAM OFDM system, with a Saleh's TWT amplifier, is based on some quality measure (mean square error, the required training time to reach a particular quality level, and computation complexity. The chosen adaptive predistortions (NN structures associated with an adaptive algorithm have a low complexity, fast convergence, and best performance.

  5. Development of Cooperative Communication Techniques for a Network of Small Satellites and Cubesats in Deep Space

    Science.gov (United States)

    Babuscia, Alessandra; Cheung, Kar-Ming; Divsalar, Dariush; Lee, Charles

    2014-01-01

    This paper aims to address this problem by proposing cooperative communication approaches in which multiple CubeSats communicate cooperatively together to improve the link performance with respect to the case of a single satellite transmitting. Three approaches are proposed: a beam-forming approach, a coding approach, and a network approach. The approaches are applied to the specific case of a proposed constellation of CubeSats at the Lunar Lagrangian point L1 which aims to perform radio astronomy at very low frequencies (30 KHz -3 MHz). The paper describes the development of the approaches, the simulation and a graphical user interface developed in Matlab which allows to perform trade-offs across multiple constellation's configurations.

  6. A novel spectral index to automatically extract road networks from WorldView-2 satellite imagery

    Directory of Open Access Journals (Sweden)

    Kaveh Shahi

    2015-06-01

    Full Text Available This research develops a spectral index to automatically extract asphalt road networks named road extraction index (REI. This index uses WorldView-2 (WV-2 imagery, which has high spatial resolution and is multispectral. To determine the best bands for WV-2, field spectral data using a field spectroradiometer were collected. These data were then analyzed statistically. The bands were selected through the methodology of stepwise discriminant analysis. The appropriate WV-2 bands were distinguished from one another as per significant wavelengths. The proposed index is based on this classification. By applying REI to WV-2 imagery, we can extract asphalt roads accurately. Results demonstrate that REI is automated, transferable, and efficient in asphalt road extraction from high-resolution satellite imagery.

  7. Assimilation of Real-Time Satellite And Human Sensor Networks for Modeling Natural Disasters

    Science.gov (United States)

    Aulov, O.; Halem, M.; Lary, D. J.

    2011-12-01

    We describe the development of underlying technologies needed to address the merging of a web of real time satellite sensor Web (SSW) and Human Sensor Web (HSW) needed to augment the US response to extreme events. As an initial prototyping step and use case scenario, we consider the development of two major system tools that can be transitioned from research to the responding operational agency for mitigating coastal oil spills. These tools consist of the capture of Situation Aware (SA) Social Media (SM) Data, and assimilation of the processed information into forecasting models to provide incident decision managers with interactive virtual spatial temporal animations superimposed with probabilistic data estimates. The system methodologies are equally applicable to the wider class of extreme events such as plume dispersions from volcanoes or massive fires, major floods, hurricane impacts, radioactive isotope dispersions from nuclear accidents, etc. A successful feasibility demonstration of this technology has been shown in the case of the Deepwater Horizon Oil Spill where Human Sensor Networks have been combined with a geophysical model to perform parameter assessments. Flickr images of beached oil were mined from the spill area, geolocated and timestamped and converted into geophysical data. This data was incorporated into General NOAA Operational Modeling Environment (GNOME), a Lagrangian forecast model that uses near real-time surface winds, ocean currents, and satellite shape profiles of oil to generate a forecast of plume movement. As a result, improved estimates of diffusive coefficients and rates of oil spill were determined. Current approaches for providing satellite derived oil distributions are collected from a satellite sensor web of operational and research sensors from many countries, and a manual analysis is performed by NESDIS. A real time SA HSW processing system based on geolocated SM data from sources such as Twitter, Flickr, YouTube etc., greatly

  8. Community-centred Networks and Networking among Companies, Educational and Cultural Institutions and Research

    DEFF Research Database (Denmark)

    Konnerup, Ulla; Dirckinck-Holmfeld, Lone

    2010-01-01

    and research as formulated in the Triple Helix Model (Etzkowitz 2008). The article draws on a case study of NoEL, a network on e-learning among business, educational and cultural institutions and research, all in all 21 partners from all around Denmark. Focus is how networks and networking change character......This article presents visions for community-centred networks and networking among companies, educational and cultural institutions and research based on blended on- and off-line collaboration and communication. Our point of departure is the general vision of networking between government, industry...

  9. Coupling of ground biosensor networks for water monitoring with satellite observations in assessing Leptospirosis

    Science.gov (United States)

    Skouloudis, A. N.; Rickerby, D. G.

    2012-12-01

    Leptospirosis became recently a major public-health problem that is closely related with the environment (Nature review Oct 2009, Vol 7, pp 736-747). This disease originates from zoonotic pathogens associated with asymptomatic rodent carriers. Unfortunately, it effects human populations via various direct and indirect routes. This disease can claim many victims with large outbreaks during natural disasters or floods occurring during seasonal conditions. The severity of the illness ranges from subclinical infection to a fulminating fatal disease. Improved water quality monitoring techniques based on biosensor, optical, micro-fluidic and information technologies are leading to radical changes in our ability to perceive and monitor the aquatic environment. Biosensors are capable of providing specific, high spatial resolution information and allow unattended operation that will be particularly useful for water borne related diseases. Current research on biosensors is leading to solutions to problems for several contaminants that were previously irresolvable due to their high degree of complexity. Networking of the sensors enables sensitive monitoring systems allowing real-time monitoring of pollutants and facilitates data transmission between the measurement points and central control stations for continuous surveillance and to provide an early warning capability. The application of intelligent biosensor networks for water quality monitoring and detection of localized sources of pollution are discussed together with the setting up of a methodology that utilizes images from satellite coupled with in-situ sensors for anticipating the zones of potential evolution of this disease and assessing the population at risk. Environmental and climatic conditions that are associated the outbreaks are described and the rational of combining earth observations coupled with advanced in-situ biosensors is explained. The implementation of sensor networks for data collection and exposure

  10. The utility of satellite fire product accuracy information - Perspectives and recommendations from the southern Africa fire network

    NARCIS (Netherlands)

    Roy, D.P.; Trigg, S.N.; Bhima, R.; Brockett, B.H.; Mutanga, O.; Virgilo, S.

    2006-01-01

    This correspondence gives Southern Africa Fire Network (SAFNet) perspectives on the utility of satellite fire product accuracy information, drawing on two main sources: insights gained during SAFNet's six years of working together, and relevant findings from a SAFNet focus group study that explored

  11. Destination directed packet switch architecture for a 30/20 GHz FDMA/TDM geostationary communication satellite network

    Science.gov (United States)

    Ivancic, William D.; Shalkhauser, Mary JO

    1991-01-01

    Emphasis is on a destination directed packet switching architecture for a 30/20 GHz frequency division multiplex access/time division multiplex (FDMA/TDM) geostationary satellite communication network. Critical subsystems and problem areas are identified and addressed. Efforts have concentrated heavily on the space segment; however, the ground segment was considered concurrently to ensure cost efficiency and realistic operational constraints.

  12. Circuit-switch architecture for a 30/20-GHz FDMA/TDM geostationary satellite communications network

    Science.gov (United States)

    Ivancic, William D.

    1992-01-01

    A circuit switching architecture is described for a 30/20 GHz frequency division, multiple access uplink/time division multiplexed downlink (FDMA/TDM) geostationary satellite communications network. Critical subsystems and problem areas are identified and addressed. Work was concentrated primarily on the space segment; however, the ground segment was considered concurrently to ensure cost efficiency and realistic operational constraints.

  13. Destination-directed, packet-switching architecture for 30/20-GHz FDMA/TDM geostationary communications satellite network

    Science.gov (United States)

    Ivancic, William D.; Shalkhauser, Mary JO

    1992-01-01

    A destination-directed packet switching architecture for a 30/20-GHz frequency division multiple access/time division multiplexed (FDMA/TDM) geostationary satellite communications network is discussed. Critical subsystems and problem areas are identified and addressed. Efforts have concentrated heavily on the space segment; however, the ground segment has been considered concurrently to ensure cost efficiency and realistic operational constraints.

  14. Planning for Applications of Communications Satellites in Education.

    Science.gov (United States)

    O'Connell, William K.

    This report of a project to develop and test a prototype system for the delivery of continuing education (CE) to two defined target groups of registered dietitians includes user needs, alternative approaches, the operational plan, the management plan, and personnel. Major tasks involved in the project are described: (1) development,…

  15. An overview of neural network applications for soil moisture retrieval from radar satellite sensors

    Science.gov (United States)

    Santi, E.; Paloscia, S.; Pettinato, S.

    2014-10-01

    Frequent and spatially distributed measurements of soil moisture (SMC), at different spatial scales, are advisable for all applications related to the environmental disciplines, such as climatology, meteorology, hydrology and agriculture. Satellite sensors operating in the low part of microwave spectrum are very suitable for this purpose, and their signals can be directly related to the moisture content of the observed surfaces, provided that all the contributions from soil and vegetation to the measured signal are properly accounted for. Among the algorithms used for the retrieval of SMC from both active (i.e. Synthetic Aperture Radar, SAR or real aperture radars) and passive (radiometers) microwave sensors, the artificial neural networks (ANN) represent the best compromise between accuracy and computation speed. ANN based algorithms have been developed at IFAC, and adapted to several radar and radiometric satellite sensors, in order to generate SMC products at different spatial resolutions, varying from hundreds of meters to tens of kilometers. These algorithms, which use the ANN techniques for inverting theoretical and semi-empirical models, such as Advanced Integral Equation (AIEM), Oh models, and Radiative transfer Theory (RTT), have been adapted to the C-band acquisitions from SAR (Envisat/ASAR) and real aperture radar (ASCAT) and to the X-band SAR acquisitions of Cosmo-SkyMed and TerraSAR-X. Moreover, a specific ANN algorithm has also been implemented for the L-band active and passive acquisitions of the incoming SMAP mission. The latter satellite will carry onboard simultaneously one radar and one radiometer operating at the same frequency, but with different spatial resolutions (3 and 40 km, respectively). Large datasets of co-located satellite acquisitions and direct SMC measurements on several test sites located worldwide have been used along with simulations derived from forward electromagnetic models for setting up, training and validating these

  16. Nurturing Global Collaboration and Networked Learning in Higher Education

    Science.gov (United States)

    Cronin, Catherine; Cochrane, Thomas; Gordon, Averill

    2016-01-01

    We consider the principles of communities of practice (CoP) and networked learning in higher education, illustrated with a case study. iCollab has grown from an international community of practice connecting students and lecturers in seven modules across seven higher education institutions in six countries, to a global network supporting the…

  17. Potential of Social Networking Sites for Distance Education Student Engagement

    Science.gov (United States)

    Lester, Jaime; Perini, Michael

    2010-01-01

    This chapter explores the potential of social networking sites for increasing student engagement for distance education learners. The authors present a modified student engagement model with a focus on the integration of technology, specifically social networking sites for community college distance education learners. The chapter concludes with…

  18. Potential of Social Networking Sites for Distance Education Student Engagement

    Science.gov (United States)

    Lester, Jaime; Perini, Michael

    2010-01-01

    This chapter explores the potential of social networking sites for increasing student engagement for distance education learners. The authors present a modified student engagement model with a focus on the integration of technology, specifically social networking sites for community college distance education learners. The chapter concludes with…

  19. Exploring Educational and Cultural Adaptation through Social Networking Sites

    Science.gov (United States)

    Ryan, Sherry D.; Magro, Michael J.; Sharp, Jason H.

    2011-01-01

    Social networking sites have seen tremendous growth and are widely used around the world. Nevertheless, the use of social networking sites in educational contexts is an under explored area. This paper uses a qualitative methodology, autoethnography, to investigate how social networking sites, specifically Facebook[TM], can help first semester…

  20. Social Network Methods for the Educational and Psychological Sciences

    Science.gov (United States)

    Sweet, Tracy M.

    2016-01-01

    Social networks are especially applicable in educational and psychological studies involving social interactions. A social network is defined as a specific relationship among a group of individuals. Social networks arise in a variety of situations such as friendships among children, collaboration and advice seeking among teachers, and coauthorship…

  1. Social Network Theory in Engineering Education

    Science.gov (United States)

    Simon, Peter A.

    Collaborative groups are important both in the learning environment of engineering education and, in the real world, the business of engineering design. Selecting appropriate individuals to form an effective group and monitoring a group's progress are important aspects of successful task performance. This exploratory study looked at using the concepts of cognitive social structures, structural balance, and centrality from social network analysis as well as the measures of emotional intelligence. The concepts were used to analyze potential team members to examine if an individual's ability to perceive emotion in others and the self and to use, understand, and manage those emotions are a factor in a group's performance. The students from a capstone design course in computer engineering were used as volunteer subjects. They were formed into groups and assigned a design exercise to determine whether and which of the above-mentioned tools would be effective in both selecting teams and predicting the quality of the resultant design. The results were inconclusive with the exception of an individual's ability to accurately perceive emotions. The instruments that were successful were the Self-Monitoring scale and the accuracy scores derived from cognitive social structures and Level IV of network levels of analysis.

  2. Integrated Services Digital Network (ISDN) status and opportunities for satellite systems

    Science.gov (United States)

    Casas, J. M.; Burke, W. R.

    1987-05-01

    The driving force behind the proposed Integrated Digital Services Network (ISDN) is identified as PTT's and industry. It is doubtful whether ISDN can satisfy business user requirements. For residential users, the prospects are even more uncertain, since the costs associated with the implementation of subscriber loops seem to be out of all proportion to the added value offered to end users in terms of new services. The evolution of IDN in Europe is such that it will leave substantial areas without digital connectivity for many years; morever, the transition from IDN to ISDN still requires the solution of many important problems at different levels of the network. Although ISDN can be expected to be offered gradually at national level in several countries in the coming years, access on a European scale will not be possible to any significant degree before the year 2000 and it will continue to remain unclear whether this offer will correspond to a real demand. It is shown that satellites could be of considerable help in solving Europe's communications problems. By providing instant coverage of the entire West European region, they can offer the benefits of ISDN wherever they are required.

  3. Delay analysis of an integrated voice and data access protocol with collision detection for multimedia satellite networks

    Science.gov (United States)

    Poon, Charles C. K.; Suda, Tatsuya

    1992-03-01

    The novel multiple-access scheme for multimedia satellite networks presented is based on a combination of FDMA and TDMA, integrating both circuit and packet-switching techniques. While the circuit-switching method is used to transmit such stream-type traffic as real-time voice communications, packet-switching is used to transmit such 'bursty' traffic as interactive data. A ground radio network is assumed for control signaling; the tone sense multiple access/partial collision detection scheme is implemented on this network to enhance the integrated access scheme's performance.

  4. Industry leading satellite based GNSS (Global Navigation Satellite System) positioning and monitoring solutions with real-time CORS (Continuously Operating Reference Station) networks

    Science.gov (United States)

    Janousek, Martin

    2010-05-01

    Real-Time CORS (Continuously Operating Reference Station Networks) today are typically GNSS networks for positioning and monitoring purposes. Real-Time networks can consist of a few stations for a local network up to nation- or continental wide networks with several hundred CORS stations. Such networks use wide area modeling of GNSS error sources including ionospheric, tropospheric and satellite orbit correction parameters to produce highest precision and efficiency method of positioning using GNSS. In 1998 Trimble Navigation Ltd. introduced a method of surveying with a non-physical or computed base station, called VRS (Virtual Reference Station). It is the most widely supported method of producing a network solution for precise carrier phase positioning in the industry. Surveying historically required one base as the fixed point of reference, and one or multiple rovers using that point of reference to compute their location by processing a vector result, either in real-time or in a postprocessed sense. Real-time survey is often referred to as RTK, short for real-time kinematic, and as the name suggests the results are in real time and you can move. The power of VRS is in the ability to compute a real-time wide-area solution to the factors that cause single base methods to degrade with distance. Namely, ionospheric and tropospheric modeling, and satellite orbit corrections. This is achieved by the reference network of CORS. A wide scattering of CORS across a state, typically 50-70km in mid-latitudes, creates a ground based sampling which significantly reduces the distance dependent errors that accumulate in the single base-rover relationship described early. Furthermore, GNSS networks can be used for real-time monitoring purposes at various distance range. Trimble Integrity Manager software provides a suite of motion engines designed to detect and quantify any movement in a range of scales from slow, creeping movement like subsidence, through sudden events such as

  5. Public and private dichotomy: social networking in higher education

    OpenAIRE

    Benson, Vladlena

    2011-01-01

    While the use of online social networking services (SNS) is still largely attributed to leisure communication, online social networking services are gaining popularity in education and business. Social networks tie individuals together and online social networking services enable these ties through technology. People flock to web sites like Facebook, MySpace, and Tribe.net to keep in touch with friends, interest groups and family, communicate and share news about them. User friendliness of s...

  6. Community-centred Networks and Networking among Companies, Educational and Cultural Institutions and Research

    DEFF Research Database (Denmark)

    Konnerup, Ulla; Dirckinck-Holmfeld, Lone

    2010-01-01

    and research as formulated in the Triple Helix Model (Etzkowitz 2008). The article draws on a case study of NoEL, a network on e-learning among business, educational and cultural institutions and research, all in all 21 partners from all around Denmark. Focus is how networks and networking change character...

  7. Swarm Utilisation Analysis: LEO satellite observations for the ESA's SSA Space Weather network

    Science.gov (United States)

    Kervalishvili, Guram; Stolle, Claudia; Rauberg, Jan; Olsen, Nils; Vennerstrøm, Susanne; Gullikstad Johnsen, Magnar; Hall, Chris

    2017-04-01

    ESA's (European Space Agency) constellation mission Swarm was successfully launched on 22 November 2013. The three satellites achieved their final constellation on 17 April 2014 and since then Swarm-A and Swarm-C orbiting the Earth at about 470 km (flying side-by-side) and Swarm-B at about 520 km altitude. Each of Swarm satellite carries instruments with high precision to measure magnetic and electric fields, neutral and plasma densities, and TEC (Total Electron Content) for which a dual frequency GPS receiver is used. SUA (Swarm Utilisation Analysis) is a project of the ESA's SSA (Space Situational Awareness) SWE (Space Weather) program. Within this framework GFZ (German Research Centre for Geosciences, Potsdam, Germany) and DTU (National Space Institute, Kongens Lyngby, Denmark) have developed two new Swarm products ROT (Rate Of change of TEC) and PEJ (Location and intensity level of Polar Electrojets), respectively. ROT is derived as the first time derivative from the Swarm measurements of TEC at 1 Hz sampling. ROT is highly relevant for users in navigation and communications: strong plasma gradients cause GPS signal degradation or even loss of GPS signal. Also, ROT is a relevant space weather asset irrespective of geomagnetic activity, e.g., high amplitude values of ROT occur during all geomagnetic conditions. PEJ is derived from the Swarm measurements of the magnetic field strength at 1 Hz sampling. PEJ has a high-level importance for power grid companies since the polar electrojet is a major cause for ground-induced currents. ROT and PEJ together with five existing Swarm products TEC, electron density, IBI (Ionospheric Bubble Index), FAC (Field-Aligned Current), and vector magnetic field build the SUA service prototype. This prototype will be integrated into ESA's SSA Space Weather network as a federated service and will be available soon from ESA's SSA SWE Ionospheric Weather and Geomagnetic Conditions Expert Service Centres (ESCs).

  8. Enhancement of primary education using EDUSAT: Rajiv Gandhi project for EDUSAT supported elementary education network (RGPEEE) overview

    Science.gov (United States)

    Desai, Vikram; Murthy, Jagdish; Saksena, Ravi; Gupta, Ajay

    2009-11-01

    Providing education access to the children in the age group 6-14 years is a constitutional obligation and challenge for the union as well state governments, as the development of elementary education is a key factor for a nation's development. Due to the non-availability of required number of trained and expert teachers' knowledge-divide exists between students population of urban and rural/remote areas. To bridge this gap Distance Learning or Tele-education is the best option. A dedicated satellite for the purpose (EDUSAT) was launched on 20th September 2004 to serve the nation in all the education activities. It was decided to provide a Tele-education network in and around the Sidhi district of Madhya Pradesh, with uplink and studio facility (Hub) at Jabalpur (MP) and around 700 receive only terminals (ROTs) in various schools. Since the medium of teaching used in this network is Hindi, it was later decided to extend the coverage to connect around 50 primary schools with ROTs in six surrounding states viz. Jharkhand, Bihar, Chhatisgarh, Uttar Pradesh, Rajasthan and Uttaranchal. The network is configured as a DTH network using state-of-art digital technology, in Ku-band with 3.8 m antenna and 16 W power amplifier at Hub. The ROTs are designed to operate on solar power for 2.5 h continuously, taking into consideration the non-availability of primary power in the rural areas. The teachers of the schools are trained for the proper operations of the ROTs. The teachers of these rural schools also contribute to the content generation, with local relevance, in coordination with Indira Gandhi National Open University (IGNOU). At present the network with around 1000 ROTs is being utilized for 2 h per day. The RGPEEE network is in the process of being augmented with 32 satellite interactive terminals (SITs), to be used for teachers training. The project is being managed by two tier management system. In order to oversee the project implementation and monitoring an Apex Core

  9. The Elements of a Network to Educate for World Security.

    Science.gov (United States)

    Network to Educate for World Security, New York, NY.

    This publication examines efforts to educate for peace and disarmament. A proposal by the Network to Educate for World Security for the establishment of a United Nations sponsored disarmament fund devoted to worldwide peace and security education is presented in Section One. Section Two contains papers that suggest how the traditional way to…

  10. Contribution of MODIS Derived Snow Cover Satellite Data into Artificial Neural Network for Streamflow Estimation

    Science.gov (United States)

    Uysal, Gokcen; Arda Sorman, Ali; Sensoy, Aynur

    2014-05-01

    Contribution of snowmelt and correspondingly snow observations are highly important in mountainous basins for modelers who deal with conceptual, physical or soft computing models in terms of effective water resources management. Long term archived continuous data are needed for appropriate training and testing of data driven approaches like artificial neural networks (ANN). Data is scarce at the upper elevations due to the difficulty of installing sufficient automated SNOTEL stations; thus in literatures many attempts are made on the rainfall dominated basins for streamflow estimation studies. On the other hand, optical satellites can easily detect snow because of its high reflectance property. MODIS (Moderate Resolution Imaging Spectroradiometer) satellite that has two platforms (Terra and Aqua) provides daily and 8-daily snow images for different time periods since 2000, therefore snow cover data (SCA) may be useful as an input layer for ANN applications. In this study, a multi-layer perceptron (MLP) model is trained and tested with precipitation, temperature, radiation, previous day discharges as well as MODIS daily SCA data. The weights and biases are optimized with fastest and robust Levenberg-Marquardt backpropagation algorithm. MODIS snow cover images are removed from cloud coverage using certain filtering techniques. The Upper Euphrates River Basin in eastern part of Turkey (10 250 km2) is selected as the application area since it is fed by snowmelt approximately 2/3 of total annual volume during spring and early summer. Several input models and ANN structures are investigated to see the effect of the contributions using 10 years of data (2001-2010) for training and validation. The accuracy of the streamflow estimations is checked with statistical criteria (coefficient of determination, Nash-Sutcliffe model efficiency, root mean square error, mean absolute error) and the results seem to improve when SCA data is introduced. Furthermore, a forecast study is

  11. Cubic Satellites, Vanguard Technology Integration, an Educational Opportunity of Modernization in Mexico

    Science.gov (United States)

    Moreno-Franco, Olmo A.; Muñoz-Ubando, L. A.; Moreno-Moreno, Prudenciano; Vargas-Méndez, Eduardo E.

    This paper provides a theoretical approach on the CubeSat standard making a cost-benefit analysis in the use of pico-satellites at the education and technology integration model for educational modernization. With the CubeSat format is planned to develop an orbit LEO pico-satellite as part of a multidisciplinary project led by the Robotics Institute of Yucatan (TRIY), assisted with previous experience in Mexico and Colombia, to build a satellite capable of stabilizing through a robotic device, which will be a training model for human resources in Mexico. The CubeSat initiative represents a technological development of more than 10 years who is still alive and growing, attracting new participants from different educational institutions and global business, which has proven to be a project that would be made and successful results with a significant low budget compared to other space missions, and finally is an opportunity to bring students and teachers to the aerospace industry, through a convergence of technology, and academic discipline.

  12. Comparison of global irradiance measurements of the official Spanish radiometric network for 2006 with satellite estimated data

    Directory of Open Access Journals (Sweden)

    J. M. Sancho

    2011-01-01

    Full Text Available The monthly average values of daily global irradiance measured in broadband at 40 stations of the National Radiometric Network of the Spanish Meteorological Agency have been compared with the monthly values of SIS (Surface Incoming Shortwave radiation of the Climate Monitoring-Satellite Application Facility for 2006. It is calculated by the data from the instrument Spinning Enhanced Visible and Infrared Imager of the Meteosat Second Generation satellite and of the Advanced Very High Resolution Radiometer of the NOAA polar satellites. The results show a great similarity between the data from both sources of information, and the discrepancies found are around 5%. The aim of such a comparison is to evaluate the suitability of the use of the SIS data for the elaboration of an atlas of solar irradiance available in Spain.

  13. Alternative packet switch architectures for a 30/20 GHz FDMA/TDMA geostationary communication satellite network

    Science.gov (United States)

    Stehle, Roy; Ogier, Richard G.

    1995-01-01

    This study has investigated alternatives for realizing a packet-based network switch for deployment on a communication satellite. The emphasis was on the avoidance of contention problems that can occur due to the simultaneous arrival of an excessive number of packets destined for the same downlink dwell. The study was to look ahead, beyond the current Advanced Communications Technology Satellite (ACTS) capability, to the next generation of satellites. The study has not been limited by currently available technology, but has used university and commercial research efforts as a basis for designs that can be readily constructed and launched within the next five years. Tradeoffs in memory requirement, power requirement, and architecture have been considered as a part of our study.

  14. Spatiotemporal interpolation of discharge across a river network by using synthetic SWOT satellite data

    Science.gov (United States)

    Paiva, Rodrigo C. D.; Durand, Michael T.; Hossain, Faisal

    2015-01-01

    Recent efforts have sought to estimate river discharge and other surface water-related quantities using spaceborne sensors, with better spatial coverage but worse temporal sampling as compared with in situ measurements. The Surface Water and Ocean Topography (SWOT) mission will provide river discharge estimates globally from space. However, questions on how to optimally use the spatially distributed but asynchronous satellite observations to generate continuous fields still exist. This paper presents a statistical model (River Kriging-RK), for estimating discharge time series in a river network in the context of the SWOT mission. RK uses discharge estimates at different locations and times to produce a continuous field using spatiotemporal kriging. A key component of RK is the space-time river discharge covariance, which was derived analytically from the diffusive wave approximation of Saint Venant's equations. The RK covariance also accounts for the loss of correlation at confluences. The model performed well in a case study on Ganges-Brahmaputra-Meghna (GBM) River system in Bangladesh using synthetic SWOT observations. The correlation model reproduced empirically derived values. RK (R2=0.83) outperformed other kriging-based methods (R2=0.80), as well as a simple time series linear interpolation (R2=0.72). RK was used to combine discharge from SWOT and in situ observations, improving estimates when the latter is included (R2=0.91). The proposed statistical concepts may eventually provide a feasible framework to estimate continuous discharge time series across a river network based on SWOT data, other altimetry missions, and/or in situ data.

  15. Linked to innovation : Shaping an innovative climate through network intentionality and educators' social network position

    NARCIS (Netherlands)

    Moolenaar, Nienke M.; Daly, Alan J.; Cornelissen, Frank; Liou, Yi Hwa; Caillier, Stacey; Riordan, Rob; Wilson, Kelly; Cohen, N. Andrew

    2014-01-01

    This study investigates whether educators' cognitive and structural social capital is associated with perceptions of innovative climate in charter schools. We explore a new concept to assess educators' cognitive social capital, namely network intentionality, meaning the extent to which an educator i

  16. Understanding Classrooms through Social Network Analysis: A Primer for Social Network Analysis in Education Research

    Science.gov (United States)

    Grunspan, Daniel Z.; Wiggins, Benjamin L.; Goodreau, Steven M.

    2014-01-01

    Social interactions between students are a major and underexplored part of undergraduate education. Understanding how learning relationships form in undergraduate classrooms, as well as the impacts these relationships have on learning outcomes, can inform educators in unique ways and improve educational reform. Social network analysis (SNA)…

  17. Using remote sensing satellite data and artificial neural network for prediction of potato yield in Bangladesh

    Science.gov (United States)

    Akhand, Kawsar; Nizamuddin, Mohammad; Roytman, Leonid; Kogan, Felix

    2016-09-01

    Potato is one of the staple foods and cash crops in Bangladesh. It is widely cultivated in all of the districts and ranks second after rice in production. Bangladesh is the fourth largest potato producer in Asia and is among the world's top 15 potato producing countries. The weather condition for potato cultivation is favorable during the sowing, growing and harvesting period. It is a winter crop and is cultivated during the period of November to March. Bangladesh is mainly an agricultural based country with respect to agriculture's contribution to GDP, employment and consumption. Potato is a prominent crop in consideration of production, its internal demand and economic value. Bangladesh has a big economic activities related to potato cultivation and marketing, especially the economic relations among farmers, traders, stockers and cold storage owners. Potato yield prediction before harvest is an important issue for the Government and the stakeholders in managing and controlling the potato market. Advanced very high resolution radiometer (AVHRR) based satellite data product vegetation health indices VCI (vegetation condition index) and TCI (temperature condition index) are used as predictors for early prediction. Artificial neural network (ANN) is used to develop a prediction model. The simulated result from this model is encouraging and the error of prediction is less than 10%.

  18. Learning Oriented Region-based Convolutional Neural Networks for Building Detection in Satellite Remote Sensing Images

    Science.gov (United States)

    Chen, C.; Gong, W.; Hu, Y.; Chen, Y.; Ding, Y.

    2017-05-01

    The automated building detection in aerial images is a fundamental problem encountered in aerial and satellite images analysis. Recently, thanks to the advances in feature descriptions, Region-based CNN model (R-CNN) for object detection is receiving an increasing attention. Despite the excellent performance in object detection, it is problematic to directly leverage the features of R-CNN model for building detection in single aerial image. As we know, the single aerial image is in vertical view and the buildings possess significant directional feature. However, in R-CNN model, direction of the building is ignored and the detection results are represented by horizontal rectangles. For this reason, the detection results with horizontal rectangle cannot describe the building precisely. To address this problem, in this paper, we proposed a novel model with a key feature related to orientation, namely, Oriented R-CNN (OR-CNN). Our contributions are mainly in the following two aspects: 1) Introducing a new oriented layer network for detecting the rotation angle of building on the basis of the successful VGG-net R-CNN model; 2) the oriented rectangle is proposed to leverage the powerful R-CNN for remote-sensing building detection. In experiments, we establish a complete and bran-new data set for training our oriented R-CNN model and comprehensively evaluate the proposed method on a publicly available building detection data set. We demonstrate State-of-the-art results compared with the previous baseline methods.

  19. AERONET-OC: Strengths and Weaknesses of a Network for the Validation of Satellite Coastal Radiometric Products

    Science.gov (United States)

    Zibordi, Giuseppe; Holben, Brent; Slutsker, Ilya; Giles, David; D'Alimonte, Davide; Melin, Frederic; Berthon, Jean-Francois; Vandemark, Doug; Feng, Hui; Schuster, Gregory; Fabbri, Bryan E.; Kaitala, Seppo; Seppala, Jukka

    2008-01-01

    The Ocean Color component of the Aerosol Robotic Network (AERONET-OC) has been implemented to support long-term satellite ocean color investigations through cross-site consistent and accurate measurements collected by autonomous radiometer systems deployed on offshore fixed platforms. The ultimate purpose of AERONET-OC is the production of standardized measurements performed at different sites with identical measuring systems and protocols, calibrated using a single reference source and method, and processed with the same code. The AERONET-OC primary data product is the normalized water leaving radiance determined at center-wavelengths of interest for satellite ocean color applications, with an uncertainty lower than 5% in the blue-green spectral regions and higher than 8% in the red. Measurements collected at 6 sites counting the northern Adriatic Sea, the Baltic Proper, the Gulf of Finland, the Persian Gulf, and, the northern and southern margins of the Middle Atlantic Bay, have shown the capability of producing quality assured data over a wide range of bio-optical conditions including Case-2 yellow substance- and sedimentdominated waters. This work briefly introduces network elements like: deployment sites, measurement method, instrument calibration, processing scheme, quality-assurance, uncertainties, data archive and products accessibility. Emphases is given to those elements which underline the network strengths (i.e., mostly standardization of any network element) and its weaknesses (i.e., the use of consolidated, but old-fashioned technology). The work also addresses the application of AERONET-OC data to the validation of primary satellite radiometric products over a variety of complex coastal waters and finally provides elements for the identification of new deployment sites most suitable to support satellite ocean color missions.

  20. Robust adjustment of a geodetic network measured by satellite technology in the Dargovských Hrdinov suburb

    Directory of Open Access Journals (Sweden)

    Slavomír Labant

    2011-12-01

    Full Text Available This article addresses the adjustment of a 3D geodetic network in the Dargovských Hrdinov suburbs using Global Navigation SatelliteSystems (GNSS for the purposes of deformation analysis. The advantage of using the GNSS compared to other terrestrial technology is thatit is not influenced by unpredictability in the ground level atmosphere and individual visibilities between points in the observed network arenot necessary. This article also includes the planning of GNSS observations using Planning Open Source software from Trimble as well assubsequent observations at individual network points. The geodetic network is processing on the basis of the Gauss-Markov model usingthe least square method and robust adjustment. From robust methods, Huber’s Robust M-estimation and Hampel’s Robust M-estimationwere used. Individual adjustments were tested and subsequently the results of analysis were graphically visualised using absolute confidenceellipsoids.

  1. Educational Seismology in Michigan: The MIQuakes Network

    Science.gov (United States)

    Fujita, K.; DeWolf, C. L.; Ruddock, J.; Svoboda, M. R.; Sinclair, J.; Schepke, C.; Waite, G. P.

    2013-12-01

    MIQuakes is a K-14 educational seismograph network currently consisting of 17 schools, mostly located in Michigan's lower peninsula. It is operated under the auspices of the Michigan Earth Science Teachers Association (MESTA) and is part of the IRIS Seismographs in Schools program. Although individual teachers in Michigan have had instruments as early as 1992, MESTA formed MIQuakes in 2010 to support the development of activities associated with classroom seismology appropriate for grades 6-12 and relevant to the Midwest, using locally recorded data. In addition, the deployment of the EarthScope transportable array in Michigan during 2011-2014 offered a tie in with a national-level research program. Michigan State University (MSU) and Michigan Tech provide content and technical support. In keeping with MESTA's philosophy of 'teachers helping teachers,' MIQuakes became, first and foremost, a group supported by teachers. Earthquake 'alerts' initially issued by MSU, were soon taken over by teachers who took the initiative in alerting each other to events, especially those that occurred during the school day. In-service teachers and university faculty have jointly organized workshops at MSU and at MESTA conferences - with teachers increasingly providing activities for sharing and relating the program to the new national standards. Workshops held to date have covered such topics as recognizing arrivals, filtering, focal mechanisms, and the Tohoku earthquake. As the group has grown, the degree of involvement and level of expertise have become broader, resulting in very different expectations from different teachers. How to keep the network cohesive, yet meet the needs of the individual members, will be one of the challenges of the next few years. Three levels of involvement by teachers are seen in the near term: those who operate their own classroom seismometer (currently either the short-period IRIS AS-1 or the broadband EAS-S102 seismometers); those who stream a nearby

  2. ATS-6 - A satellite for human needs. [Health, Education, Telecommunications Experiment

    Science.gov (United States)

    Whalen, A. A.; Johnston, W. A., Jr.

    1975-01-01

    On May 30, 1974, NASA launched the ATS-6 experimental communications satellite into a geosynchronous orbit at a station centered over the United States. The 1400 kg satellite was designed to be body-stabilized with a 3-axis control system capable of precision offset pointing. It deployed a 9.1 meter (30 foot) parabolic reflector antenna with a transponder that covered a frequency range from VHF through C-band. The high RF gains obtained with the antenna were to be used for many dramatic communications experiments, one of which was the Health/Education Telecommunications Experiment (HET), a demonstration of direct broadcast of color television to low cost terminals in remote regions of the United States. More than 120 terminals with 3-meter antennas were deployed in Alaska, Washington, the Rocky Mountains, and Appalachia to provide educational and health services to selected community centers. After 11 months of nearly continuous service, the performance of both the satellite and the experiment have exceeded all expectations.

  3. ATS-6 - A satellite for human needs. [Health, Education, Telecommunications Experiment

    Science.gov (United States)

    Whalen, A. A.; Johnston, W. A., Jr.

    1975-01-01

    On May 30, 1974, NASA launched the ATS-6 experimental communications satellite into a geosynchronous orbit at a station centered over the United States. The 1400 kg satellite was designed to be body-stabilized with a 3-axis control system capable of precision offset pointing. It deployed a 9.1 meter (30 foot) parabolic reflector antenna with a transponder that covered a frequency range from VHF through C-band. The high RF gains obtained with the antenna were to be used for many dramatic communications experiments, one of which was the Health/Education Telecommunications Experiment (HET), a demonstration of direct broadcast of color television to low cost terminals in remote regions of the United States. More than 120 terminals with 3-meter antennas were deployed in Alaska, Washington, the Rocky Mountains, and Appalachia to provide educational and health services to selected community centers. After 11 months of nearly continuous service, the performance of both the satellite and the experiment have exceeded all expectations.

  4. Social networks in medical education in bosnia and herzegovina.

    Science.gov (United States)

    Masic, Izet; Sivic, Suad; Pandza, Haris

    2012-01-01

    Beginning with the late twentieth and early twenty-first century, the Internet was a significant additional tool in the education of teenagers. Later, it takes more and more significant role in educating students and professionals. The aim of this paper is to investigate, to what extent and how effectively the Internet is used today by students of biomedical faculties in Bosnia and Herzegovina. In addition, more specifically, this paper will research the implications of the well-known social networks in education of students and health professionals in Bosnia and Herzegovina. We compared the ratio of using Social networks by students for spreading medical information as basics for health education at medical faculties at 3 universities in Bosnia and Herzegovina (B&H). The results showed that only 11.6% of professors use Facebook type of social network, 49.3% of them have a profile on BiomedExperts scientific social network and 79% have available articles in the largest biomedical literature database MEDLINE. Students are also frequent users of general social networks and educational clips from You Tube, which they prefer to utilize considerably more than the other types of professionals. Students rarely use the facilities of professional social networks, because they contain mainly data and information needed for further, postgraduate professional education. In B&H there are decent conditions for the use of online social networks in the education of health professionals. While students enthusiastically embraced these opportunities, this is not so much a case with health care professionals in practice; while scientific health care workers have not shown greater interest in the use of social networks, both for purposes of scientific research and in terms of self-education and training of students.

  5. Nurturing global collaboration and networked learning in higher education

    OpenAIRE

    Cronin, Catherine; Cochrane, Thomas; Gordon, Averill

    2016-01-01

    We consider the principles of communities of practice (CoP) and networked learning in higher education, illustrated with a case study. iCollab has grown from an international community of practice connecting students and lecturers in seven modules across seven higher education institutions in six countries, to a global network supporting the exploration and evaluation of mobile web tools to engage in participatory curriculum development and supporting students in developing international coll...

  6. Measuring QoS in an Aeronautical Opportunistic Network Architecture with Limited Access to a Satellite Communications Backhaul

    Directory of Open Access Journals (Sweden)

    Rubén Martínez-Vidal

    2016-01-01

    Full Text Available We measure quality of service (QoS in a wireless network architecture of transoceanic aircraft. A distinguishing characteristic of the network scheme we analyze is that it mixes the concept of Delay Tolerant Networking (DTN through the exploitation of opportunistic contacts, together with direct satellite access in a limited number of the nodes. We provide a graph sparsification technique for deriving a network model that satisfies the key properties of a real aeronautical opportunistic network while enabling scalable simulation. This reduced model allows us to analyze the impact regarding QoS of introducing Internet-like traffic in the form of outgoing data from passengers. Promoting QoS in DTNs is usually really challenging due to their long delays and scarce resources. The availability of satellite communication links offers a chance to provide an improved degree of service regarding a pure opportunistic approach, and therefore it needs to be properly measured and quantified. Our analysis focuses on several QoS indicators such as delivery time, delivery ratio, and bandwidth allocation fairness. Obtained results show significant improvements in all metric indicators regarding QoS, not usually achievable on the field of DTNs.

  7. Going Social: The Impact of Social Networking in Promoting Education

    Science.gov (United States)

    Jain, Neelesh Kumar; Verma, Ashish; Verma, Rama Shankar; Tiwari, Prashant

    2012-01-01

    The growth and the popularity of the Social networks has a high impact on the development of the students in the field of Personality, Attitudes, Knowledge and on its whole academic performance in classroom and society. This paper envisage on the impact of Social Network on Education and Training of the students.

  8. Bluetooth-Assisted Context-Awareness in Educational Data Networks

    Science.gov (United States)

    Gonzalez-Castano, F. J.; Garcia-Reinoso, J.; Gil-Castineira, F.; Costa-Montenegro, E.; Pousada-Carballo, J. M.

    2005-01-01

    In this paper, we propose an auxiliary "location network", to support user-independent context-awareness in educational data networks; for example, to help visitors in a museum. We assume that, in such scenarios, there exist "service servers" that need to be aware of user location in real-time. Specifically, we propose the implementation of a…

  9. China's Education Policy-Making: A Policy Network Perspective

    Science.gov (United States)

    Han, Shuangmiao; Ye, Fugui

    2017-01-01

    Policy network approach has become a broadly accepted and frequently adopted practice in modern state governance, especially in the public sector. The study utilises a broadly defined policy network conceptual frame and categories of reference to trace the evolution of education policy-making in China. The study uses "The Outline of China's…

  10. Bluetooth-Assisted Context-Awareness in Educational Data Networks

    Science.gov (United States)

    Gonzalez-Castano, F. J.; Garcia-Reinoso, J.; Gil-Castineira, F.; Costa-Montenegro, E.; Pousada-Carballo, J. M.

    2005-01-01

    In this paper, we propose an auxiliary "location network", to support user-independent context-awareness in educational data networks; for example, to help visitors in a museum. We assume that, in such scenarios, there exist "service servers" that need to be aware of user location in real-time. Specifically, we propose the implementation of a…

  11. Hierarchical Network Models for Education Research: Hierarchical Latent Space Models

    Science.gov (United States)

    Sweet, Tracy M.; Thomas, Andrew C.; Junker, Brian W.

    2013-01-01

    Intervention studies in school systems are sometimes aimed not at changing curriculum or classroom technique, but rather at changing the way that teachers, teaching coaches, and administrators in schools work with one another--in short, changing the professional social networks of educators. Current methods of social network analysis are…

  12. Collaborative Network Management for Enhancing Quality Education of Primary Schools

    Science.gov (United States)

    Chaikoed, Wisithsak; Sirisuthi, Chaiyuth; Numnaphol, Kochaporn

    2017-01-01

    This research aims to study the network and collaborative factors that enhance quality education of primary schools. Different methods were used in this research work: (1) Related approaches, theories, and research literatures and (2) Scholars were interviewed on 871 issues in the form of questionnaire, and the collaborative network factors were…

  13. Social networking in nursing education: integrative literature review

    Science.gov (United States)

    Kakushi, Luciana Emi; Évora, Yolanda Dora Martinez

    2016-01-01

    Abstract Objective: to identify the use of social networking in nursing education. Method: integrative literature review in the databases: LILACS, IBECS, Cochrane, BDENF, SciELO, CINAHL, Scopus, PubMed, CAPES Periodicals Portal and Web of Science, using the descriptors: social networking and nursing education and the keywords: social networking sites and nursing education, carried out in April 2015. Results: of the 489 articles found, only 14 met the inclusion and exclusion criteria. Most studies were published after 2013 (57%), originating from the United States and United Kingdom (77.8%). It was observed the use of social networking among nursing students, postgraduate students, mentors and nurses, in undergraduate programmes, hybrid education (blended-learning) and in interprofessional education. The social networking sites used in the teaching and learning process were Facebook (42.8%), Ning (28.5%), Twitter (21.4%) and MySpace (7.1%), by means of audios, videos, quizzes, animations, forums, guidance, support, discussions and research group. Conclusion: few experiences of the use of social networking in nursing education were found and their contributions show the numerous benefits and difficulties faced, providing resourses for the improvement and revaluation of their use in the teaching and learning process. PMID:27384465

  14. Social networking in nursing education: integrative literature review

    Directory of Open Access Journals (Sweden)

    Luciana Emi Kakushi

    Full Text Available Abstract Objective: to identify the use of social networking in nursing education. Method: integrative literature review in the databases: LILACS, IBECS, Cochrane, BDENF, SciELO, CINAHL, Scopus, PubMed, CAPES Periodicals Portal and Web of Science, using the descriptors: social networking and nursing education and the keywords: social networking sites and nursing education, carried out in April 2015. Results: of the 489 articles found, only 14 met the inclusion and exclusion criteria. Most studies were published after 2013 (57%, originating from the United States and United Kingdom (77.8%. It was observed the use of social networking among nursing students, postgraduate students, mentors and nurses, in undergraduate programmes, hybrid education (blended-learning and in interprofessional education. The social networking sites used in the teaching and learning process were Facebook (42.8%, Ning (28.5%, Twitter (21.4% and MySpace (7.1%, by means of audios, videos, quizzes, animations, forums, guidance, support, discussions and research group. Conclusion: few experiences of the use of social networking in nursing education were found and their contributions show the numerous benefits and difficulties faced, providing resourses for the improvement and revaluation of their use in the teaching and learning process.

  15. Research on a New Program of Satellite Network Security Certification%一种新型卫星网络安全认证方案的研究

    Institute of Scientific and Technical Information of China (English)

    高婧; 朱晨光

    2011-01-01

    在卫星网络通信中,卫星的安全防护是卫星通信系统建设的重要内容之一.结合卫星网络的特点,在对卫星网络的安全认证需求进行分析的基础上,提出了一种基于ELGamal数字签名的卫星网络安全双向认证方案,以解决卫星干扰、非法盗用卫星资源的问题;克服了传统认证方案中普遍存在的认证效率较低和认证过程较复杂等问题,如将该方案加以推广,可以广泛采用.%In the communication of satellite network, the security of satellite is an important content in the development of satellite communication system.Combining with the characteristics of satellite network and analyzing the safety certification requirements of satellite network, a two-way satellite network security certification program based on EIGamal digital signature is introduced to address the satellite interference, illegal use of satellite resources, and overcome the low efficiency and complex process certification existed in traditional common certification.This program can he widely adopted.

  16. Combined Geometric and Neural Network Approach to Generic Fault Diagnosis in Satellite Actuators and Sensors

    DEFF Research Database (Denmark)

    Baldi, P.; Blanke, Mogens; Castaldi, P.

    2016-01-01

    This paper presents a novel scheme for diagnosis of faults affecting the sensors measuring the satellite attitude, body angular velocity and flywheel spin rates as well as defects related to the control torques provided by satellite reaction wheels. A nonlinear geometric design is used to avoid...... on a detailed nonlinear satellite model with embedded disturbance description. The results document the efficacy of the proposed diagnosis scheme....

  17. A Methodology For Measuring Resilience in a Satellite-Based Communication Network

    Science.gov (United States)

    2014-03-27

    In the cyber realm, most satellite operators were in compliance with the National Security Agency’s (NSA) approved encryptions for transmissions...and more continue to meet compliance as new satellites are placed in orbit. Along with the encryptions , many 17 satellite operators utilize “deaf...nation at war may be of higher concern than the nation providing backdoor support which is higher than a neutral nation, and so on until a region not

  18. Network of educational investigation: Teaching innovatio

    OpenAIRE

    Rosana de Pablo Redondo

    2011-01-01

    The new educational reality, with the introduction of the European Higher Education Area (EHEA; and new requirements for education require a rethinking of the teaching process, which will use new technologies as key instruments. However, the concept of educational innovation goes beyond the widespread use of Information Technologies (IT). Structural changes are needed in educational institutions, which must be reorganized according to a new paradigm.This paper presents the strategic transform...

  19. Satellite/Terrestrial Networks: End-to-End Communication Interoperability Quality of Service Experiments

    Science.gov (United States)

    Ivancic, William D.

    1998-01-01

    Various issues associated with satellite/terrestrial end-to-end communication interoperability are presented in viewgraph form. Specific topics include: 1) Quality of service; 2) ATM performance characteristics; 3) MPEG-2 transport stream mapping to AAL-5; 4) Observation and discussion of compressed video tests over ATM; 5) Digital video over satellites status; 6) Satellite link configurations; 7) MPEG-2 over ATM with binomial errors; 8) MPEG-2 over ATM channel characteristics; 8) MPEG-2 over ATM over emulated satellites; 9) MPEG-2 transport stream with errors; and a 10) Dual decoder test.

  20. ESPACE - a geodetic Master's program for the education of Satellite Application Engineers

    Science.gov (United States)

    Hedman, K.; Kirschner, S.; Seitz, F.

    2012-04-01

    involved in ESPACE. This paper will first give the background and objectives of ESPACE with focus on its specific position in geodetic education programmes. Second, we will introduce the interdisciplinary study program and explain the involvement of external teaching staff. Further we will give an up-to-date description of current students and ESPACE alumni. The job market and international demand for satellite application engineers will be shown especially with focus to geodetic fields.

  1. Analysing the Correlation between Social Network Analysis Measures and Performance of Students in Social Network-Based Engineering Education

    Science.gov (United States)

    Putnik, Goran; Costa, Eric; Alves, Cátia; Castro, Hélio; Varela, Leonilde; Shah, Vaibhav

    2016-01-01

    Social network-based engineering education (SNEE) is designed and implemented as a model of Education 3.0 paradigm. SNEE represents a new learning methodology, which is based on the concept of social networks and represents an extended model of project-led education. The concept of social networks was applied in the real-life experiment,…

  2. Higher Education Change and Social Networks: A Review of Research

    Science.gov (United States)

    Kezar, Adrianna

    2014-01-01

    This article reviews literature on the potential for understanding higher education change processes through social network analysis (SNA). In this article, the main tenets of SNA are reviewed and, in conjunction with organizational theory, are applied to higher education change to develop a set of hypotheses that can be tested in future research.

  3. The Role of Transnational Networking for Higher Education Academics

    Science.gov (United States)

    Wakefield, Kelly; Dismore, Harriet

    2015-01-01

    Amidst rapid socio-economic change, higher education (HE) academics across the world face major challenges to its organisation, finance and management. This paper discusses the role of transnational networking in higher education. Data from 40 interviews with geographically distributed academics engaged in learning and teaching transnational…

  4. Extending the Network and Content of Adult Education Workers.

    Science.gov (United States)

    Draper, James A.

    1989-01-01

    Building networks of workers in the field of adult education can strengthen the sharing of ideas and resources, understanding, social action, knowledge diffusion, and democratization of research. Adult education as a social movement can thus be given the impetus to bring about change. (SK)

  5. Developing a new global network of river reaches from merged satellite-derived datasets

    Science.gov (United States)

    Lion, C.; Allen, G. H.; Beighley, E.; Pavelsky, T.

    2015-12-01

    In 2020, the Surface Water and Ocean Topography satellite (SWOT), a joint mission of NASA/CNES/CSA/UK will be launched. One of its major products will be the measurements of continental water extent, including the width, height, and slope of rivers and the surface area and elevations of lakes. The mission will improve the monitoring of continental water and also our understanding of the interactions between different hydrologic reservoirs. For rivers, SWOT measurements of slope must be carried out over predefined river reaches. As such, an a priori dataset for rivers is needed in order to facilitate analysis of the raw SWOT data. The information required to produce this dataset includes measurements of river width, elevation, slope, planform, river network topology, and flow accumulation. To produce this product, we have linked two existing global datasets: the Global River Widths from Landsat (GRWL) database, which contains river centerline locations, widths, and a braiding index derived from Landsat imagery, and a modified version of the HydroSHEDS hydrologically corrected digital elevation product, which contains heights and flow accumulation measurements for streams at 3 arcsecond spatial resolution. Merging these two datasets requires considerable care. The difficulties, among others, lie in the difference of resolution: 30m versus 3 arseconds, and the age of the datasets: 2000 versus ~2010 (some rivers have moved, the braided sections are different). As such, we have developed custom software to merge the two datasets, taking into account the spatial proximity of river channels in the two datasets and ensuring that flow accumulation in the final dataset always increases downstream. Here, we present our preliminary results for a portion of South America and demonstrate the strengths and weaknesses of the method.

  6. Integrating Satellite, Aircraft, and Ground-Based Observations to Improve a GHG Inventory Network

    Science.gov (United States)

    Midzik, M.; Abbate, J.; Raheja, G.

    2016-12-01

    Methane (CH4) is the second-most effective greenhouse gas, with a global warming potential up to 70 times that of carbon dioxide (CO2) over the span of 25 years. With a majority of these emissions attributed to livestock, landfill, and wastewater treatment, CH4 emissions are a concern for both urban and rural landscapes. Though Earth-observing satellites can effectively monitor mid-to-upper tropospheric CH4 on a global scale, current instrumentation is limited in its capacity to accurately measure near-surface CH4 on a local scale. The Bay Area Air Quality Management District (BAAQMD) regulates stationary sources of air pollution in the nine counties surrounding San Francisco Bay. BAAQMD traditionally estimates emissions using a bottom-up approach, combining emissions factor and activity data to estimate source emissions per sector. However, recent literature suggests that these bottom-up approaches are underestimating CH4 emissions by nearly 50% in many regions of California. In efforts to address the discrepancy, this project compares BAAQMD's current CH4 spatial emissions inventory with top-down sub-Planetary Boundary Layer aircraft measurements from the NASA Alpha Jet Atmospheric eXperiment (AJAX). Together, these different approaches were used to identify CH4 hot-spots in the San Francisco Bay Area. In addition, sources of high-CH4 anomalies were identified using USGS high resolution aerial imagery and trajectory analysis. Furthermore, this project used NASA Landsat 8 imagery and USGS orthoimagery to classify the types of indicated emissions and infer other points of interest not included in the current BAAQMD inventory. These findings help pinpoint specific sites for BAAQMD's upcoming Mobile GHG Measurement Network; furthermore, results from this project suggest future sites for coincident data collection between advancing bottom-up and top-down instruments.

  7. Nurturing global collaboration and networked learning in higher education

    Directory of Open Access Journals (Sweden)

    Catherine Cronin

    2016-03-01

    Full Text Available We consider the principles of communities of practice (CoP and networked learning in higher education, illustrated with a case study. iCollab has grown from an international community of practice connecting students and lecturers in seven modules across seven higher education institutions in six countries, to a global network supporting the exploration and evaluation of mobile web tools to engage in participatory curriculum development and supporting students in developing international collaboration and cooperation skills. This article explores the interplay of collaboration and cooperation, CoP and networked learning; describes how this interplay has operated in iCollab; and highlights opportunities and challenges of learning, teaching and interacting with students in networked publics in higher education.

  8. Network Reputational Risks of the Educational Institution

    Science.gov (United States)

    Bekturganov, Zakir Z.

    2016-01-01

    Development of the global information space is the basis of change in the educational paradigm and the formation of the world market of educational services. Traditional educational institutions face new challenges and risks that undermine their competitiveness. This implies the emerging phenomenon of online reputation risks, with significant…

  9. All Sky Imager Network for Science and Education

    Science.gov (United States)

    Bhatt, A.; Kendall, E. A.; Zalles, D. R.; Baumgardner, J. L.; Marshall, R. A.; Kaltenbacher, E.

    2012-12-01

    A new all sky imager network for space weather monitoring and education outreach has been developed by SRI International. The goal of this program is to install sensitive, low-light all-sky imagers across the continental United States to observe upper atmospheric airglow and aurora in near real time. While aurora borealis is often associated with the high latitudes, during intense geomagnetic storms it can extend well into the continental United States latitudes. Observing auroral processes is instrumental in understanding the space weather, especially in the times of increasing societal dependence on space-based technologies. Under the THEMIS satellite program, Canada has installed a network of all-sky imagers across their country to monitor aurora in real-time. However, no comparable effort exists in the United States. Knowledge of the aurora and airglow across the entire United States in near real time would allow scientists to quickly assess the impact of a geomagnetic storm in concert with data from GPS networks, ionosondes, radars, and magnetometers. What makes this effort unique is that we intend to deploy these imagers at high schools across the country. Selected high-schools will necessarily be in rural areas as the instrument requires dark night skies. At the commencement of the school year, we plan to give an introductory seminar on space weather at each of these schools. Science nuggets developed by SRI International in collaboration with the Center for GeoSpace Studies and the Center for Technology in Learning will be available for high school teachers to use during their science classes. Teachers can use these nuggets as desired within their own curricula. We intend to develop a comprehensive web-based interface that will be available for students and scientific community alike to observe data across the network in near real time and also to guide students towards complementary space weather data sets. This interface will show the real time extent of

  10. Assessing Collaboration Networks in Educational Research: A Co-Authorship-Based Social Network Analysis Approach

    Science.gov (United States)

    Munoz, David Andres; Queupil, Juan Pablo; Fraser, Pablo

    2016-01-01

    Purpose: The purpose of this paper is to analyze collaboration networks and their patterns among higher education institutions (HEIs) in Chile and the Latin American region. This will provide evidence to educational managements in order to properly allocate their efforts to improve collaboration. Design/methodology/approach: This quantitative…

  11. Connectivism: the educational theory of networks

    OpenAIRE

    2013-01-01

    The significant use of electronic media in everyday life requires new considerations about learning, about communication, about being in the spaces of ubiquity. Siemenes (2005) proposed the theory of networks, the learning through networks, the connections between nodes, which Landow (2006), Bolter (1991, 1996, 2001), Cassany (2012) have at different times called even if other terms. The relevance of the theory of Connectivism offers new fields of investigation and experimentation for t...

  12. The use of social-networking sites in medical education.

    Science.gov (United States)

    Cartledge, Peter; Miller, Michael; Phillips, Bob

    2013-10-01

    A social-network site is a dedicated website or application which enables users to communicate with each other and share information, comments, messages, videos and images. This review aimed to ascertain if "social-networking sites have been used successfully in medical education to deliver educational material", and whether "healthcare professionals, and students, are engaging with social-networking sites for educational purposes". A systematic-review was undertaken using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Eight databases were searched with pre-defined search terms, limits and inclusion criteria. Data was extracted into a piloted data-table prior to the narrative-synthesis of the Quality, Utility, Extent, Strength, Target and Setting of the evidence. 1047 articles were identified. Nine articles were reviewed with the majority assessing learner satisfaction. Higher outcome measures were rarely investigated. Educators used Facebook, Twitter, and a custom-made website, MedicineAfrica to achieve their objectives. Social-networking sites have been employed without problems of professionalism, and received positive feedback from learners. However, there is no solid evidence base within the literature that social-networking is equally or more effective than other media available for educational purposes.

  13. Design of a search and rescue terminal based on the dual-mode satellite and CDMA network

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The current goal is to create a set of portable terminals with GPS/BD2 dual-mode satellite positioning, vital signs monitoring and wireless transmission functions. The terminal depends on an ARM processor to collect and combine data related to vital signs and GPS/BD2 location information, and sends the message to headquarters through the military CDMA network. It integrates multiple functions as a whole. The satellite positioning and wireless transmission capabilities are integrated into the motherboard, and the vital signs sensors used in the form of belts communicate with the board through Bluetooth. It can be adjusted according to the headquarters’ instructions. This kind of device is of great practical significance for operations during disaster relief, search and rescue of the wounded in wartime, non-war military operations and other special circumstances.

  14. Design of a search and rescue terminal based on the dual-mode satellite and CDMA network

    Science.gov (United States)

    Zhao, Junping; Zhang, Xuan; Zheng, Bing; Zhou, Yubin; Song, Hao; Song, Wei; Zhang, Meikui; Liu, Tongze; Zhou, Li

    2010-12-01

    The current goal is to create a set of portable terminals with GPS/BD2 dual-mode satellite positioning, vital signs monitoring and wireless transmission functions. The terminal depends on an ARM processor to collect and combine data related to vital signs and GPS/BD2 location information, and sends the message to headquarters through the military CDMA network. It integrates multiple functions as a whole. The satellite positioning and wireless transmission capabilities are integrated into the motherboard, and the vital signs sensors used in the form of belts communicate with the board through Bluetooth. It can be adjusted according to the headquarters' instructions. This kind of device is of great practical significance for operations during disaster relief, search and rescue of the wounded in wartime, non-war military operations and other special circumstances.

  15. Dynamic Neural Network-Based Pulsed Plasma Thruster (PPT) Fault Detection and Isolation for Formation Flying of Satellites

    Science.gov (United States)

    Valdes, A.; Khorasani, K.

    The main objective of this paper is to develop a dynamic neural network-based fault detection and isolation (FDI) scheme for the Pulsed Plasma Thrusters (PPTs) that are used in the Attitude Control Subsystem (ACS) of satellites that are tasked to perform a formation flying mission. By using data collected from the relative attitudes of the formation flying satellites our proposed "High Level" FDI scheme can detect the pair of thrusters which is faulty, however fault isolation cannot be accomplished. Based on the "High Level" FDI scheme and the DNN-based "Low Level" FDI scheme developed earlier by the authors, an "Integrated" DNN-based FDI scheme is then proposed. To demonstrate the FDI capabilities of the proposed schemes various fault scenarios are simulated.

  16. Integration of Education: Using Social Media Networks to Engage Students

    Directory of Open Access Journals (Sweden)

    Risa Blair

    2014-10-01

    Full Text Available Any educator today will tell you that the strategies used in the classroom have evolved and changed with the access everyone has to technology. In a world with constant changes and shifts because of immediate access to information, the way course content is delivered must evolve and adjust to the new ways students learn. Engagement of students in course content and reaching learning objectives are the key elements educators strive for in every course. Enter social media networks and the ability to leverage the user activity with these applications in education. Now, educators can provide content which engages students and meets learning objectives the way students want to learn. By reviewing social media networks: Facebook, Pinterest, Instagram, Blogs, Twitter, and Evernote, educators can position themselves to be as technology-savvy as today's students.

  17. Energy-Efficient Network Transmission between Satellite Swarms and Earth Stations Based on Lyapunov Optimization Techniques

    Directory of Open Access Journals (Sweden)

    Weiwei Fang

    2014-01-01

    Full Text Available The recent advent of satellite swarm technologies has enabled space exploration with a massive number of picoclass, low-power, and low-weight spacecraft. However, developing swarm-based satellite systems, from conceptualization to validation, is a complex multidisciplinary activity. One of the primary challenges is how to achieve energy-efficient data transmission between the satellite swarm and terrestrial terminal stations. Employing Lyapunov optimization techniques, we present an online control algorithm to optimally dispatch traffic load among different satellite-ground links for minimizing overall energy consumption over time. Our algorithm is able to independently and simultaneously make control decisions on traffic dispatching over intersatellite-links and up-down-links so as to offer provable energy and delay guarantees, without requiring any statistical information of traffic arrivals and link condition. Rigorous analysis and extensive simulations have demonstrated the performance and robustness of the proposed new algorithm.

  18. Monitoring Animal Behaviour and Environmental Interactions Using Wireless Sensor Networks, GPS Collars and Satellite Remote Sensing

    National Research Council Canada - National Science Library

    Handcock, Rebecca N; Swain, Dave L; Bishop-Hurley, Greg J; Patison, Kym P; Wark, Tim; Valencia, Philip; Corke, Peter; O'Neill, Christopher J

    2009-01-01

    ...). We explore this concept using a case-study from an extensive cattle enterprise in northern Australia and demonstrate the potential for combining GPS collars and satellite images in a WSN to monitor...

  19. Satellite- and Epoch Differenced Precise Point Positioning Based on a Regional Augmentation Network

    Directory of Open Access Journals (Sweden)

    Bin Wu

    2012-06-01

    Full Text Available Precise Point Positioning (PPP has been demonstrated as a simple and effective approach for user positioning. The key issue in PPP is how to shorten convergence time and improve positioning efficiency. Recent researches mainly focus on the ambiguity resolution by correcting residual phase errors at a single station. The success of this approach (referred to hereafter as NORM-PPP is subject to how rapidly one can fix wide-lane and narrow-lane ambiguities to achieve the first ambiguity-fixed solution. The convergence time of NORM-PPP is receiver type dependent, and normally takes 15–20 min. Different from the general algorithm and theory by which the float ambiguities are estimated and the integer ambiguities are fixed, we concentrate on a differential PPP approach: the satellite- and epoch differenced (SDED approach. In general, the SDED approach eliminates receiver clocks and ambiguity parameters and thus avoids the complicated residual phase modeling procedure. As a further development of the SDED approach, we use a regional augmentation network to derive tropospheric delay and remaining un-modeled errors at user sites. By adding these corrections and applying the Robust estimation, the weak mathematic properties due to the ED operation is much improved. Implementing this new approach, we need only two epochs of data to achieve PPP positioning converging to centimeter-positioning accuracy. Using seven days of GPS data at six CORS stations in Shanghai, we demonstrate the success rate, defined as the case when three directions converging to desired positioning accuracy of 10 cm, reaches 100% when the interval between the two epochs is longer than 15 min. Comparing the results of 15 min’ interval to that of 10 min’, it is observed that the position RMS improves from 2.47, 3.95, 5.78 cm to 2.21, 3.93, 4.90 cm in the North, East and Up directions, respectively. Combining the SDED coordinates at the starting point and the ED relative

  20. Satellite- and epoch differenced precise point positioning based on a regional augmentation network.

    Science.gov (United States)

    Li, Haojun; Chen, Junping; Wang, Jiexian; Wu, Bin

    2012-01-01

    Precise Point Positioning (PPP) has been demonstrated as a simple and effective approach for user positioning. The key issue in PPP is how to shorten convergence time and improve positioning efficiency. Recent researches mainly focus on the ambiguity resolution by correcting residual phase errors at a single station. The success of this approach (referred to hereafter as NORM-PPP) is subject to how rapidly one can fix wide-lane and narrow-lane ambiguities to achieve the first ambiguity-fixed solution. The convergence time of NORM-PPP is receiver type dependent, and normally takes 15-20 min. Different from the general algorithm and theory by which the float ambiguities are estimated and the integer ambiguities are fixed, we concentrate on a differential PPP approach: the satellite- and epoch differenced (SDED) approach. In general, the SDED approach eliminates receiver clocks and ambiguity parameters and thus avoids the complicated residual phase modeling procedure. As a further development of the SDED approach, we use a regional augmentation network to derive tropospheric delay and remaining un-modeled errors at user sites. By adding these corrections and applying the Robust estimation, the weak mathematic properties due to the ED operation is much improved. Implementing this new approach, we need only two epochs of data to achieve PPP positioning converging to centimeter-positioning accuracy. Using seven days of GPS data at six CORS stations in Shanghai, we demonstrate the success rate, defined as the case when three directions converging to desired positioning accuracy of 10 cm, reaches 100% when the interval between the two epochs is longer than 15 min. Comparing the results of 15 min' interval to that of 10 min', it is observed that the position RMS improves from 2.47, 3.95, 5.78 cm to 2.21, 3.93, 4.90 cm in the North, East and Up directions, respectively. Combining the SDED coordinates at the starting point and the ED relative coordinates thereafter, we

  1. Three-month performance evaluation of the Nanometrics, Inc., Libra Satellite Seismograph System in the northern California Seismic Network

    Science.gov (United States)

    Oppenheimer, David H.

    2000-01-01

    In 1999 the Northern California Seismic Network (NCSN) purchased a Libra satellite seismograph system from Nanometrics, Inc to assess whether this technology was a cost-effective and robust replacement for their analog microwave system. The system was purchased subject to it meeting the requirements, criteria and tests described in Appendix A. In early 2000, Nanometrics began delivery of various components of the system, such as the hub and remote satellite dish and mounting hardware, and the NCSN installed and assembled most equipment in advance of the arrival of Nanometrics engineers to facilitate the configuration of the system. The hub was installed in its permanent location, but for logistical reasons the "remote" satellite hardware was initially configured at the NCSN for testing. During the first week of April Nanometrics engineers came to Menlo Park to configure the system and train NCSN staff. The two dishes were aligned with the satellite, and the system was fully operational in 2 days with little problem. Nanometrics engineers spent the remaining 3 days providing hands-on training to NCSN staff in hardware/software operation, configuration, and maintenance. During the second week of April 2000, NCSN staff moved the entire remote system of digitizers, dish assembly, and mounting hardware to Mammoth Lakes, California. The system was reinstalled at the Mammoth Lakes water treatment plant and communications successfully reestablished with the hub via the satellite on 14 April 2000. The system has been in continuous operation since then. This report reviews the performance of the Libra system for the three-month period 20 April 2000 through 20 July 2000. The purpose of the report is to assess whether the system passed the acceptance tests described in Appendix A. We examine all data gaps reported by NCSN "gap list" software and discuss their cause.

  2. Project Work in Networked Distance Education

    DEFF Research Database (Denmark)

    Knudsen, Morten; Helbo, Jan; Jensen, Lars Peter

    2000-01-01

    . As the experience since then has proven this to be a very successful innovation in higher education [1], it seems to be an obvious idea also to base our new distance educations on the project study form. Traditionally, however, distance education has been characterized by one-way communication and self......-study, whereas the project study form is based on collaboration and dialogue. Consequently, successful implementation of project work in distance education requires extensive utilisation of new information and communication technology. In this paper the experiences of project work in a new Master of Industrial...... Information Technology distance education is described. The program is offered through Open University, and the students have a BSc degree or equivalent and at least 2 years of relevant professional experience - and a full-time job. The students are assumed to study 20 hours per week, half of the time being...

  3. A CDMA Spotbeam Architecture for the Next Generation Satellite System (NGSS) for the Aeronautical Telecommunications Network (ATN)

    Science.gov (United States)

    Raghavan, Rajesh S.; Shamma, Mohammed A.

    2003-01-01

    This paper will present work being done to model and simulate a CDMA based Mobile Satellite System architecture for providing all or part of the future Air Traffic Management (ATM) services. Such a system, will help in relieving the dependence on ground based networks, if not eliminate it. Additionally such an architecture can be used in parallel or as a supplementary service along with ground based links to help alleviate any capacity bottlenecks, or in areas where such services are difficult to make available such as in oceanic, remote areas outside the jet highways, or in developing countries where ground services are less available.

  4. Satellite altimetry and GOCE contribution to the pre-definition of the Kingdom of Saudi Arabia (KSA) Vertical Network

    Science.gov (United States)

    Vergos, Georgios S.; Grebenitcharsky, Rossen S.; Natsiopoulos, Dimitrios A.; Al-Kherayef, Othman; Al-Muslmani, Bandar

    2017-04-01

    The availability of a unified and well-established national vertical system and frame is of outmost importance in support of everyday geodetic, surveying and engineering applications. Vertical reference system (VRS) modernization and unification has gained increased importance especially during the last years due to the advent of gravity-field dedicated missions and GOCE in particular, since it is the first time that an unprecedented in accuracy dataset of gravity field functionals has become available at a global scale. The Kingdom of Saudi Arabia VRS is outdated and exhibits significant tilts and biases, so that during the last couple of years an extensive effort has been put forth in order to: re-measure by traditional levelling the entire network, establish new benchmarks (BMs), perform high-quality absolute and relative gravity observations and construct new tide-gauge (TG) stations in both the Arab and Red Seas. The Current work focuses on the combined analysis of the existing, recently collected, terrestrial observations with satellite altimetry data and the latest GOCE-based Earth Geopotential Models (EGMs) in order to provide a pre-definition of the KSA VRS. To that respect, a 30-year satellite altimetry time-series is constructed for each TG station in order to derive both the Mean Sea Level (MSL) as well as the sea level trends. This information is analyzed, through Wavelet (WL) Multi-resolution Analysis (MRA), with the TG sea level records in order to determine annual, semi-annual and secular trends of the Red and Arab Sea variations. Finally, the so-derived trends and MSL are combined with local gravity observations at the TG BMs, levelling offsets between the TGs and the network BMs, levelling observations between the network BMs themselves and GOCE-based EGM-derived geoid heights and potential values. The validation of GOCE contribution and of the satellite altimetry derived MSL and trends is based on a simultaneous adjustment of the entire KSA

  5. Program on application of communications satellites to educational development: Design of a 12 channel FM microwave receiver. [color television from communication satellites

    Science.gov (United States)

    Risch, C. O.; Rosenbaum, F. J.; Gregory, R. O.

    1974-01-01

    The design, fabrication, and performance of elements of a low cost FM microwave satellite ground station receiver is described. It is capable of accepting 12 contiguous color television equivalent bandwidth channels in the 11.72 to 12.2 GHz band. Each channel is 40 MHz wide and incorporates a 4 MHz guard band. The modulation format is wideband FM and the channels are frequency division multiplexed. Twelve independent CATV compatible baseband outputs are provided. The overall system specifications are first discussed, then consideration is given to the receiver subsystems and the signal branching network.

  6. A Space for Critical Research on Education Policy: ECER Paper Sessions and the "Policy Studies and Politics of Education" Network

    Science.gov (United States)

    Rasmussen, Palle

    2014-01-01

    The activities of the European Educational Research Association (EERA) and the yearly European Conference on Educational Research (ECER) are mainly organised in standing networks. Through the example of the Policy Studies and Politics of Education network, this article takes a closer look at network activity and the ways in which it contributes to…

  7. Effects of Social Networking on Adolescent Education

    Science.gov (United States)

    Miah, Muhammed; Omar, Adnan; Allison-Golding, Monique

    2013-01-01

    In recent years, the use of social networking sites has grown tremendously especially among the teens and high school students. However, very little is known about the scale of use, the purpose, how students use these sites and, more specifically, whether these sites help or hurt their academic progress. This study investigates how high school…

  8. Energy-Efficient Transmissions for Remote Wireless Sensor Networks: An Integrated HAP/Satellite Architecture for Emergency Scenarios.

    Science.gov (United States)

    Dong, Feihong; Li, Hongjun; Gong, Xiangwu; Liu, Quan; Wang, Jingchao

    2015-09-03

    A typical application scenario of remote wireless sensor networks (WSNs) is identified as an emergency scenario. One of the greatest design challenges for communications in emergency scenarios is energy-efficient transmission, due to scarce electrical energy in large-scale natural and man-made disasters. Integrated high altitude platform (HAP)/satellite networks are expected to optimally meet emergency communication requirements. In this paper, a novel integrated HAP/satellite (IHS) architecture is proposed, and three segments of the architecture are investigated in detail. The concept of link-state advertisement (LSA) is designed in a slow flat Rician fading channel. The LSA is received and processed by the terminal to estimate the link state information, which can significantly reduce the energy consumption at the terminal end. Furthermore, the transmission power requirements of the HAPs and terminals are derived using the gradient descent and differential equation methods. The energy consumption is modeled at both the source and system level. An innovative and adaptive algorithm is given for the energy-efficient path selection. The simulation results validate the effectiveness of the proposed adaptive algorithm. It is shown that the proposed adaptive algorithm can significantly improve energy efficiency when combined with the LSA and the energy consumption estimation.

  9. Energy-Efficient Transmissions for Remote Wireless Sensor Networks: An Integrated HAP/Satellite Architecture for Emergency Scenarios

    Directory of Open Access Journals (Sweden)

    Feihong Dong

    2015-09-01

    Full Text Available A typical application scenario of remote wireless sensor networks (WSNs is identified as an emergency scenario. One of the greatest design challenges for communications in emergency scenarios is energy-efficient transmission, due to scarce electrical energy in large-scale natural and man-made disasters. Integrated high altitude platform (HAP/satellite networks are expected to optimally meet emergency communication requirements. In this paper, a novel integrated HAP/satellite (IHS architecture is proposed, and three segments of the architecture are investigated in detail. The concept of link-state advertisement (LSA is designed in a slow flat Rician fading channel. The LSA is received and processed by the terminal to estimate the link state information, which can significantly reduce the energy consumption at the terminal end. Furthermore, the transmission power requirements of the HAPs and terminals are derived using the gradient descent and differential equation methods. The energy consumption is modeled at both the source and system level. An innovative and adaptive algorithm is given for the energy-efficient path selection. The simulation results validate the effectiveness of the proposed adaptive algorithm. It is shown that the proposed adaptive algorithm can significantly improve energy efficiency when combined with the LSA and the energy consumption estimation.

  10. Building an educational seismic network in Romanian schools

    Science.gov (United States)

    Zaharia, Bogdan; Tataru, Dragos; Grecu, Bogdan; Ionescu, Constantin; Bican-Brisan, Nicoleta; Neagoe, Cristian

    2014-05-01

    Understanding the earthquake phenomena and their effects is an important step toward the education of population and aims to raise the awareness about the earthquake risk and possible mitigation actions. In this sense, The Romanian Educational Seismic Network project represents an efficient communication tool, allowing teaching and learning about the earthquakes and seismic wave impact through experimental practices and educational activities. The seismic network consist of nine SEP seismometers installed in high-schools from the most important seismic areas (Vrancea, Banat, Făgăraş, Dobrogea), vulnerable cities (Bucharest, Iasi) or high populated places (Cluj, Sibiu, Timisoara, Zalău) and is coordinated by the National Institute of Earth Physics from Bucharest. Once installed, the seismic network is the starting point of activities for students through an e-learning platform. Some objectives are aimed: - To train students and teachers how to make analysis and interpretation of seismological data; - To make science more interesting for students; - To improve the participation rates in physical sciences for students; - To raise awareness of geoscience as a scientific discipline for pre-university students; - To promote the installation and effective use of educational seismographs and seismic data; - To reinforce and develop relationships between participating schools and research institutes; - To create an earthquake database this will be used by students and teachers for educational purposes. Different types of practical activities using educational seismometer, designed by researchers for students, are described in educational materials and in the web platform project. Also we encourage the teachers from the participating schools to share their experiences and produce new didactic tools for the classroom. This collaborative work could illustrate the conjugated efforts of researchers and teachers for a better education and awareness of the risk culture

  11. A Proposed Precision Network Measurements Architecture for the Philippine Research, Education, and Government Information Network (PREGINET)

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The paper proposes a network measurements architecture for the Philippine research, education, and government information network (PREGINET). The proposed architecture is an NTP-based hybrid network measurements system, which offers precise measurements, easily managed, and less bandwidth-consuming system. An NTP via GPS setup is included in the architecture to provide precise time synchronization all over the network. This setup provides a precise time reference for both the source of the measurements data and the collecting or processing machines.The current network measurements implementations in PREGINET, as presented in the latter part of the paper, will provide a hint on what tools have to be developed in order to implement the proposed architecture.

  12. Teacher Agency in Educational Reform: Lessons from Social Networks Research

    Science.gov (United States)

    Datnow, Amanda

    2012-01-01

    This article provides a context for understanding how social networks among teachers support or constrain school improvement in terms of instructional practice, professional development, and educational reform. It comments on the articles in this special issue, summarizing their contributions to the field. This analysis reveals several important…

  13. Understanding Groups in Outdoor Adventure Education through Social Network Analysis

    Science.gov (United States)

    Jostad, Jeremy; Sibthorp, Jim; Paisley, Karen

    2013-01-01

    Relationships are a critical component to the experience of an outdoor adventure education (OAE) program, therefore, more fruitful ways of investigating groups is needed. Social network analysis (SNA) is an effective tool to study the relationship structure of small groups. This paper provides an explanation of SNA and shows how it was used by the…

  14. BECUN. The Educational Computer User's Network at Battelle.

    Science.gov (United States)

    Battelle Memorial Inst., Columbus, OH.

    The Educational Computer User's Network at Battelle Columbus Laboratories is a cooperative computer center effort between a group of Ohio colleges, secondary schools, and a large research-oriented organization. This description of the program includes the historical background, program concept, data processing development, hardware and software,…

  15. Teacher Agency in Educational Reform: Lessons from Social Networks Research

    Science.gov (United States)

    Datnow, Amanda

    2012-01-01

    This article provides a context for understanding how social networks among teachers support or constrain school improvement in terms of instructional practice, professional development, and educational reform. It comments on the articles in this special issue, summarizing their contributions to the field. This analysis reveals several important…

  16. The Texas Water Education Network Directory.

    Science.gov (United States)

    Texas Water Development Board, Austin.

    The resource persons and program descriptions in this directory came from answers supplied in a 1988 survey mailed to 135 entities having some relationship to or interest in promoting the distribution of water education materials suitable for use in Texas elementary or secondary schools. This directory includes an update on the programs submitted…

  17. Networking of theories as a research practice in mathematics education

    CERN Document Server

    Bikner-Ahsbahs, Angelika

    2014-01-01

    How can we deal with the diversity of theories in mathematics education This was the main question that led the authors of this book to found the Networking Theories Group. Starting from the shared assumption that the existence of different theories is a resource for mathematics education research, the authors have explored the possibilities of interactions between theories, such as contrasting, coordinating, and locally integrating them. The book explains and illustrates what it means to network theories; it presents networking as a challenging but fruitful research practice and shows how the Group dealt with this challenge considering five theoretical approaches, namely the approach of Action, Production, and Communication (APC), the Theory of Didactical Situations (TDS), the Anthropological Theory of the Didactic (ATD), the approach of Abstraction in Context (AiC), and the Theory of Interest-Dense Situations (IDS). A synthetic presentation of each theory and their connections shows how the activity of netw...

  18. On Optimization Control Parameters in an Adaptive Error-Control Scheme in Satellite Networks

    Directory of Open Access Journals (Sweden)

    Ranko Vojinović

    2011-09-01

    Full Text Available This paper presents a method for optimization of control parameters of an adaptive GBN scheme in error-prone satellite channel. Method is based on the channel model with three state, where channel have the variable noise level.

  19. Link Performance Analysis for a Proposed Future Architecture of the Air Force Satellite Control Network

    Science.gov (United States)

    2011-12-01

    data to update the known location of their spacecraft. This, of course , differs from the way STK and, in turn, the AFSCN LP obtains spacecraft...Dynamic System - A Divide and Conquer Approach. Espoo, Finland: IEEE. Cuevas, E. G., & Rehwinkel, C. A. SPOCS : A System to Measure Satellite Link

  20. Combined Geometric and Neural Network Approach to Generic Fault Diagnosis in Satellite Reaction Wheels

    DEFF Research Database (Denmark)

    Baldi, P.; Blanke, Mogens; Castaldi, P.

    2015-01-01

    This paper suggests a novel diagnosis scheme for detection, isolation and estimation of faults affecting satellite reaction wheels. Both spin rate measurements and actuation torque defects are dealt with. The proposed system consists of a fault detection and isolation module composed by a bank...

  1. Quest for learning: A study of teachers' perceptions of the Satellite Education and Environmental Research Program

    Science.gov (United States)

    Ahern, Kathryn A.

    The purpose of this study was to examine the perceptions of teachers who participated in the Satellite Education and Environmental Research (SEER) Program Water Project, a curriculum design course developed at the University of Nebraska-Lincoln. The distance education course was a complex intervention which used the Nebraska Mathematics and Science Initiative's Model Program criteria for inquiry-based curriculum. Teachers formed communities of inquiry, experienced scientific inquiry processes, integrated different disciplines to create new thematic science curricula, and were encouraged to employ innovative pedagogical practices. National Science Education Standards and Nebraska Mathematics and Science Frameworks were consulted to develop important science process skills and concepts. Multicultural science education was addressed through investigation of local water issues. Teachers were encouraged to form community partnerships, supported with testing materials for conducting scientific research, and expected to use computer technology. Grounded theory was used to examine interviews of 26 participants for their perceptions of the effects of the intervention on their teaching strategies. The self-reports were triangulated through the external evaluation report, classroom artifacts, and a limited number of observations of classroom and field activities. Open coding was used to categorize the interview responses and to propose relationships among them. The central phenomenon that emerged from the axial and select coding was the changed focus: teaching science more thematically. Three theoretical propositions were posed to guide further inquiry: (1) teachers need opportunities and resources to experience science as an authentic, tenable, and realistic process if they are to develop curriculum and focus classroom activities on scientific inquiry; (2) autonomous learning communities must be fostered at downlink sites if distance learning experiences are to affect

  2. Scientific - Educational Micro-satellite "kolibri-2000": First Results of Measurements

    Science.gov (United States)

    Klimov, S. I.; Nozdrachev, M. N.; Tamkovich, G. M.; Grushin, V. A.; Grachov, Ye. A.; Grigoryan, O. R.; Afanasyev, Yu. V.; Zaitzev, A. N.; Farnakeev, I. V.; Parrot, M.

    Space today is an environment with intensive practical activity of mankind. The results of mastering of space are used in many ways, including education. School is a natural way to inform a broad public about space research. In this paper we will present the Program of Scientific - Educational Micro-satellite http://www.iki.rssi.ru/kollibri/mission1_e.htm. The space science and technologies that can be used as teaching tools in Program are: 1) The space systems of teleme- try, television, operational meteorological observations, remote exploration of the ground, and high-precision navigational systems which have become necessary and economically feasible parts of our life. 2) The space environment also attracts at- tention, as actively influencing many highly technological systems and the biosphere of the Earth, including the health of man. Space weather is becoming as well- known as (meteorological) weather. The first project of the Program is the Russian- Australian micro-satellite "Kolibri-2000" (total mass 22 kg) which start the oper- ation at the end of February 2002. In the project, several schools participate, in- cluding Russian schools sponsored by the Institute of Atomic Energy and Tech- nology (IAET, Obninsk www.obninsk.org) and two Australian schools in Sydney, Knox Grammar School www.knox.nsw.edu.au and Ravenswood School for Girls www.ravenswood.nsw.edu.au. "Kolibri-2000" is equipped with instruments to mea- sure and study the magnetic and electric field, and the radiation belts of the Earth. In this paper we will present the first measurements on the orbit near International Space Station.

  3. Remote Sensing Education and Development Countries: Multilateral Efforts through the Committee on Earth Observation Satellites (CEOS)

    Science.gov (United States)

    Charles, Leslie Bermann

    1998-01-01

    The Committee on Earth Observation Satellites (CEOS) is an international organization which coordinates space-based Earth observations world wide. Created in 1984, CEOS now comprises 38 national space agencies, regional organizations and international space-related and research groups. The aim of CEOS is to achieve international coordination in the planning of satellite missions for Earth observation and to maximize the utilization of data from these missions world-wide. With regard to developing countries, the fundamental aim of CEOS is to encourage the creation and maintenance of indigenous capability that is integrated into the local decision-making process, thereby enabling developing countries to obtain the maximum benefit from Earth observation. Obtaining adequate access to remote sensing information is difficult for developing countries and students and teachers alike. High unit data prices, the specialized nature of the technology , difficulty in locating specific data, complexities of copyright provisions, the emphasis on "leading edge" technology and research, and the lack of training materials relating to readily understood application are frequently noted obstacles. CEOS has developed an education CD-ROM which is aimed at increasing the integration of space-based data into school curricula, meeting the heretofore unsatisfied needs of developing countries for information about Earth observation application, data sources and future plans; and raising awareness around the world of the value of Earth observation data from space. The CD-ROM is designed to be used with an Internet web browser, increasing the information available to the user, but it can also be used on a stand-alone machine. It contains suggested lesson plans and additional resources for educators and users in developing countries.

  4. A feed-forward Hopfield neural network algorithm (FHNNA) with a colour satellite image for water quality mapping

    Science.gov (United States)

    Asal Kzar, Ahmed; Mat Jafri, M. Z.; Hwee San, Lim; Al-Zuky, Ali A.; Mutter, Kussay N.; Hassan Al-Saleh, Anwar

    2016-06-01

    There are many techniques that have been given for water quality problem, but the remote sensing techniques have proven their success, especially when the artificial neural networks are used as mathematical models with these techniques. Hopfield neural network is one type of artificial neural networks which is common, fast, simple, and efficient, but it when it deals with images that have more than two colours such as remote sensing images. This work has attempted to solve this problem via modifying the network that deals with colour remote sensing images for water quality mapping. A Feed-forward Hopfield Neural Network Algorithm (FHNNA) was modified and used with a satellite colour image from type of Thailand earth observation system (THEOS) for TSS mapping in the Penang strait, Malaysia, through the classification of TSS concentrations. The new algorithm is based essentially on three modifications: using HNN as feed-forward network, considering the weights of bitplanes, and non-self-architecture or zero diagonal of weight matrix, in addition, it depends on a validation data. The achieved map was colour-coded for visual interpretation. The efficiency of the new algorithm has found out by the higher correlation coefficient (R=0.979) and the lower root mean square error (RMSE=4.301) between the validation data that were divided into two groups. One used for the algorithm and the other used for validating the results. The comparison was with the minimum distance classifier. Therefore, TSS mapping of polluted water in Penang strait, Malaysia, can be performed using FHNNA with remote sensing technique (THEOS). It is a new and useful application of HNN, so it is a new model with remote sensing techniques for water quality mapping which is considered important environmental problem.

  5. Enhancing STEM Education through Cubesats: Using Satellite Integration as a Teaching Tool at a Non-Tech School

    Science.gov (United States)

    Bernardes, S.; Cotten, D. L.

    2016-12-01

    University-based satellite programs have been successfully used as a platform for teaching STEM related fields, bringing tremendous benefits to graduate and undergraduate education. Considering their infrastructure and curricula, tech schools have traditionally been considered logical candidates for hosting such programs. More recently, with the dissemination of small satellites initiatives, non-tech schools have been presented the opportunity of developing satellite design and implementation programs. This work reports on the experiences and challenges associated with implementing a satellite program at the University of Georgia (UGA), a non-tech university. With funding from the Air Force Research Laboratory's (AFRL) University Nanosat Program (UNP) and NASA's Undergraduate Student Instrument Project (USIP) a team of undergraduates at UGA has recently been tasked with building two small satellites and helping to create a Small Satellite Research Laboratory (SSRL) at the university. Unique features of the satellite program at UGA include its team of students from a broad range of backgrounds and departments (Engineering, Computer Science, Art, Business, and Geography) and the previous exposure of many of these students to synergistic technologies, including arduino and unmanned aerial systems. We show how informal exposure to those technologies and willingness of students to focus on areas outside of their field of study can benefit from the implementation of satellite programs. In this regard, we report on methods and techniques used to find and recruit driven and knowledgeable students to work in a high paced field such as satellite system integration. We show how students and faculty from multiple departments have collaborated to reach a common, far reaching goal and describe our proposed methods to evaluate and measure educational goals based around SSRL and its projects. We also present the challenges associated with the lack of a developed engineering

  6. 卫星教学资源通过城域网传输的方案与实现%Project of Transmitting Satellite Video Teaching Resources through Metropolitan Area Network

    Institute of Scientific and Technical Information of China (English)

    薛曼芳

    2012-01-01

      The paper discusses how to use streaming media technology, satellite reception technology and existing computer, network, software and hardware resources to achieve efficient transmission, sharing and centralized management of satellite video teaching resource via Metropolitan Area Network (MAN). This project addresses the issues including uneven allocation of educational resources, difficulties in equipment management and shortage of IT supporting professionals during the implementation process of modern remote educational project of elementary and middle school in countryside. It also improves the level of information technology of education.%  探讨了如何利用流媒体技术、卫星接收技术及现有电脑网络软硬件资源,实现卫星视频教学资源在城域网内的有效传输、分享和集中管理,解决在“农村中小学现代远程教育工程”实施过程中,教育资源分配不均衡、资源和设备管理难、专业信息人员缺乏等问题,提高了教育信息化水平。

  7. Project Work in Networked Distance Education

    DEFF Research Database (Denmark)

    Knudsen, Morten; Helbo, Jan; Jensen, Lars Peter

    2000-01-01

    Problem oriented project work has been the foundation for the educational system at Aalborg University since its start 25 years ago. The duration of each student project is one semester, and the students spend half of their time working on the project in groups of typically 5-6 persons......-study, whereas the project study form is based on collaboration and dialogue. Consequently, successful implementation of project work in distance education requires extensive utilisation of new information and communication technology. In this paper the experiences of project work in a new Master of Industrial...... devoted to courses and the other half to project work. A computer conference system, LuvitÒ provides facilities for the courses, as well as structured synchronous and asynchronous communication. Eight times per year two-day seminars are held at the university for intensive lectures, project work...

  8. Social networking for nurse education: Possibilities, perils and pitfalls.

    Science.gov (United States)

    Green, Janet; Wyllie, Aileen; Jackson, Debra

    2014-01-01

    Abstract In this paper, we consider the potential and implications of using social networking sites such as Facebook® in nurse education. The concept of social networking and the use of Facebook will be explored, as will the theoretical constructs specific to the use of online technology and Web 2.0 tools. Theories around Communities of Inquiry (Garrison, Anderson, & Archer, 2000), Communities of Practice (Wenger, 1998), Activity Theory (Daniels, Cole, & Wertsch, 2007) and Actor-Network theory (Latour, 1997) will be briefly explored, as will the work of Vygotsky (1978), as applies to the social aspects of learning. Boundary issues, such as if and how faculty and students should or could be connected via social networking sites will also be explored.

  9. Social networking for nurse education: Possibilities, perils and pitfalls.

    Science.gov (United States)

    Green, Janet; Wyllie, Aileen; Jackson, Debra

    2014-03-11

    Abstract In this paper, we consider the potential and implications of using social networking sites such as Facebook® in nurse education. The concept of social networking and the use of Facebook will be explored, as will the theoretical constructs specific to the use of online technology and web 2.0 tools. Theories around Communities of Inquiry (Garrison, Anderson & Archer 2000), Communities of Practice (Wenger 1998), Activity Theory (Daniels, Cole & Wertsch 2007) and Actor Network Theory (Latour 1997) will be briefly explored, as will the work of Vygotsky (1978), as applies to the social aspects of learning. Boundary issues, such as if and how faculty and students should or could be connected via social networking sites will also be explored.

  10. Networking for Education for Sustainable Development in Austria: The Austrian ECOLOG-Schools Programme

    Science.gov (United States)

    Rauch, Franz

    2016-01-01

    This case describes networking for education for sustainable development within the Austrian ECOLOG-schools network. The article presents theoretical concepts of networks in education in general, and the organization of the ECOLOG-network in particular. Based upon these foundations, the concept and results of a participatory evaluation study are…

  11. Networking for Education for Sustainable Development in Austria: The Austrian ECOLOG-Schools Programme

    Science.gov (United States)

    Rauch, Franz

    2016-01-01

    This case describes networking for education for sustainable development within the Austrian ECOLOG-schools network. The article presents theoretical concepts of networks in education in general, and the organization of the ECOLOG-network in particular. Based upon these foundations, the concept and results of a participatory evaluation study are…

  12. Dynamic Channel Network Extraction from Satellite Imagery of the Jamuna River

    Science.gov (United States)

    Addink, E. A.; Marra, W. A.; Kleinhans, M. G.

    2010-12-01

    Evolution of the largest rivers on Earth is poorly understood while their response to global change is dramatic, such as severe drought and flooding problems. Rivers with high annual dynamics, like the Jamuna, allow us to study their response to changing conditions. Most remote-sensing work so far focused only on pixel-based analysis of channels and change detection or manual digitisation of channels, which is far from urgently needed quantifiers of pattern and pattern change. Using a series of Landsat TM images taken at irregular intervals showing inter- and intra-annual variation, we demonstrate that braided rivers can be represented as nearly chain-like directional networks. These can be studied with novel methods gleaned from neurology. These networks provide an integral spatial description of the network and should not be confused with hierarchical hydrological stream network descriptions developed in the ’60s to describe drainage basins. The images were first classified into water, bare sediment and vegetation. The contiguous water body of the river was then selected and translated into a network description with bifurcations and confluences at the nodes, and interconnecting channels. Along the entire river the well-known braiding indices were derived from the network. The channel width is a crucial attribute of the channel network as this allows the calculation of bifurcation asymmetry. The width was also used with channel length as weights to all the elements in the network in the calculation of more advanced measures for the nature and evolution of the channel network. The key step here is to describe river network evolution by identifying the same node in multiple subsequent images as well as new and abandoned nodes, in order to distinguish migration of bifurcations from avulsion processes. Once identified through time, the changes in node position and the changes in the connected channels can be quantified. These changes can potentially be linked to

  13. Rainfall measurements from cellular networks microwave links : an alternative ground reference for satellite validation and hydrology in Africa .

    Science.gov (United States)

    Gosset, Marielle; cazenave, frederic; Zougmore, françois; Doumounia, Ali; kacou, Modeste

    2015-04-01

    In many part of the Tropics the ground based gauge networks are sparse, often degrading and accessing this data for monitoring rainfall or for validating satellite products is sometime difficult. Here, an alternative rainfall measuring technique is proposed and tested in West Africa. It is based on using commercial microwave links from cellular telephone networks to detect and quantify rainfall. Rainfall monitoring based on commercial terrestrial microwave links has been tested for the first time in Burkina Faso, in Sahel. The rainfall regime is characterized by intense rainfall intensities brought by mesoscale Convective systems (MCS), generated by deep organized convection. The region is subjected to drought as well as dramatic floods associated with the intense rainfall provided by a few MCSs. The hydrometeorological risk is increasing and need to be monitored. In collaboration with the national cellular phone operator, Telecel Faso, the attenuation on 29 km long microwave links operating at 7 GHz was monitored at 1s time rate for the monsoon season 2012. The time series of attenuation is transformed into rain rates and compared with rain gauge data. The method is successful in quantifying rainfall: 95% of the rainy days are detected. The correlation with the daily raingauge series is 0.8 and the season bias is 5%. The correlation at the 5 min time step within each event is also high. We will present the quantitative results, discuss the uncertainties and compare the time series and the 2D maps with those derived from a polarimetric radar. The results demonstrate the potential interest of exploiting national and regional wireless telecommunication networks to provide rainfall maps for various applications : urban hydrology, agro-hydrological risk monitoring, satellite validation and development of combined rainfall products. We will also present the outcome of the first international Rain Cell Africa workshop held in Ouagadougou early 2015.

  14. Improving information dissemination in sparse vehicular networks by adding satellite communication

    NARCIS (Netherlands)

    Kloiber, Bernhard; Strang, Thomas; Spijker, Hanno; Heijenk, Geert

    2012-01-01

    Information dissemination in pure Vehicular Ad Hoc NETworks (VANETs) such as ITS-G5 becomes problematic when the network is sparse. In situations where the number of vehicles, that can act as a communication node, is insufficiently low, e.g. in rural areas, during night-time or because of a low mark

  15. Improving information dissemination in sparse vehicular networks by adding satellite communication

    NARCIS (Netherlands)

    Kloiber, Bernhard; Strang, Thomas; Spijker, Hanno; Heijenk, Geert

    Information dissemination in pure Vehicular Ad Hoc NETworks (VANETs) such as ITS-G5 becomes problematic when the network is sparse. In situations where the number of vehicles, that can act as a communication node, is insufficiently low, e.g. in rural areas, during night-time or because of a low

  16. Social Networking Tools and Teacher Education Learning Communities: A Case Study

    Science.gov (United States)

    Poulin, Michael T.

    2014-01-01

    Social networking tools have become an integral part of a pre-service teacher's educational experience. As a result, the educational value of social networking tools in teacher preparation programs must be examined. The specific problem addressed in this study is that the role of social networking tools in teacher education learning communities…

  17. Social Networking Tools and Teacher Education Learning Communities: A Case Study

    Science.gov (United States)

    Poulin, Michael T.

    2014-01-01

    Social networking tools have become an integral part of a pre-service teacher's educational experience. As a result, the educational value of social networking tools in teacher preparation programs must be examined. The specific problem addressed in this study is that the role of social networking tools in teacher education learning communities…

  18. Assessment of a national network: the case of the French teacher training colleges' health education network.

    Science.gov (United States)

    Guével, Marie-Renée; Jourdan, Didier

    2009-06-01

    The French teacher training colleges' health education (HE) network was set up in 2005 to encourage the inclusion of HE in courses for primary and secondary school teachers. A systematic process of monitoring the activity and the impact of this initiative was implemented. This analysis was systematically compared with the perceptions of teaching staff involved in the network. This paper assesses the network after 2 years using documents produced and interviews with 24 coordinators. Twenty-nine teacher training colleges out of a total of 31 are involved in the network. The network has helped to create links between teacher training colleges, extend HE training and encourage partnerships with other public health organizations. By 2007, HE was included in courses offered by 19 teacher training colleges as opposed to only 3 in 2005. This study not only showed the positive impact of the network but also revealed issues in its management and presented new challenges to ensure the effectiveness of the network. The network has succeeded in attracting and training trainers who were already providing or were interested in HE. Reaching other trainers who are not familiar with HE remains a challenge for the future.

  19. 卫星宽带网络系统的研究与分析%An Analytical Research on Satellite Broadband Network system

    Institute of Scientific and Technical Information of China (English)

    薛中伟

    2012-01-01

    This artical mainly introduces the satellite broadband network system basic principle,technical features, development status and trend of application, through the research and analysis,that the satellite broadband network will be widely used in information communication.%本文主要介绍了卫星宽带网络系统的基本原理、技术特点、发展现状和应用趋势,通过研究和分析,证明了卫星宽带网络在信息通信领域具有广阔的应用前景。

  20. An advanced OBP-based payload operating in an asynchronous network for future data relay satellites utilising CCSDS-standard data structures

    Science.gov (United States)

    Grant, M.; Vernucci, A.

    1991-01-01

    A possible Data Relay Satellite System (DRSS) topology and network architecture is introduced. An asynchronous network concept, whereby each link (Inter-orbit, Inter-satellite, Feeder) is allowed to operate on its own clock, without causing loss of information, in conjunction with packet data structures, such as those specified by the CCSDS for advanced orbiting systems is discussed. A matching OBP payload architecture is described, highlighting the advantages provided by the OBP-based concept and then giving some indications on the OBP mass/power requirements.

  1. Load-Aware Radio Access Selection in Future Generation Satellite-Terrestrial Wireless Networks

    Directory of Open Access Journals (Sweden)

    M. Ali

    2012-03-01

    Full Text Available In the telecommunication networks the introduction of Next Generation Wireless Networks (NGWN has been described as the most significant change in wireless communication. The convergence of different access networks in NGWN allows generalized mobility, consistency and ubiquitous provision of services to mobile users. The general target of NGWN is to transport different types of information like voice,data, and other media like video in packets form like IP. The NGWNs offer significant savings in costs to the operators along with new and interesting services to the consumers. Major challenges in NGWN are efficient resource utilization, maintaining service quality, reliability and the security. This paper proposes a solution for seamless load aware Radio Access Technology (RAT selection based on interworking of different RATs in NGWN. In this paper novel load balancing algorithms have been proposed which have been simulated on the target network architecture for TCP data services. The IEEE 802.21 Media Independent Handover (MIH is utilized in load balancing specifically for mobility management, which enable low handover latency by reducing the target network detection time. The proposed method considers the network type, signal strength, data rate and network load as primary decision parameters for RAT selection process and consists of two different algorithms, one located inthe mobile terminal and the other at the network side. The network architecture, the proposed load balancing framework and RAT selection algorithms were simulated using NS2. Different attributes like load distribution in the wireless networks and average throughput to evaluate the effects of load balancing in considered scenarios.

  2. WORKING TOGETHER: EDUCATION, RESEARCH AND DEVELOPMENT FOR 5G NETWORKS

    Directory of Open Access Journals (Sweden)

    E. P. Ivanova

    2015-12-01

    Full Text Available In the new world of globalization of ideas and mobility difficulties in knowledge diffusion still remains. The effectiveexchange of experiences and skills in new generation networks is not guaranteed by the enormous potentialsofinternetworking systems and devices. Conceptual model for performance modeling and evaluation of multiservicenetworks has been major interest for mobile networks providers. It is essential to assess the performance ofmobile system architectures in order to identify where potential bottlenecks and data packet blocking probabilityare possible to occur. Educational platforms, new simulations opportunities represent a good opportunity to reducethe digital divide and to ensure faster and higher communication trends. Several universities and companies arecurrently involved in using educational platforms to provide better results. Conceptual model for teletrafficengineering in educational platform and applications focuses on some important aspects: tutorials, exercise,simulations, and expectation values of parameters, testing and estimation of students work. In the same time thesame model is very appropriate for simulation of network management for the new generation networks. Thiseducational platform for academics, students and researchers, puts together some of the critical aspects ofdistributed systems and their characteristics, parameters and probability of blocking.

  3. Destination directed packet switch architecture for a geostationary communication satellite network

    Science.gov (United States)

    Ivancic, W. D.; Shalkhauser, M. J.; Bobinsky, E. A.; Soni, N. J.; Quintana, J. A.; Kim, H.; Wagner, P.; Vanderaar, M.

    1992-01-01

    A major effort at NASA/Lewis is to identify and develop critical digital technologies and components that enable new commercial missions or significantly improve the performance, cost efficiency, and/or reliability of existing and planned space comunications systems. NASA envisions the need for low data rate, direct to the user communications services, for data, facsimile, voice, and video conferencing. A report that focuses on destination directed packet switching architectures for geostationary communication satellites is presented.

  4. Destination directed packet switch architecture for a geostationary communication satellite network

    Science.gov (United States)

    Ivancic, W. D.; Shalkhauser, M. J.; Bobinsky, E. A.; Soni, N. J.; Quintana, J. A.; Kim, H.; Wagner, P.; Vanderaar, M.

    1992-08-01

    A major effort at NASA/Lewis is to identify and develop critical digital technologies and components that enable new commercial missions or significantly improve the performance, cost efficiency, and/or reliability of existing and planned space comunications systems. NASA envisions the need for low data rate, direct to the user communications services, for data, facsimile, voice, and video conferencing. A report that focuses on destination directed packet switching architectures for geostationary communication satellites is presented.

  5. Combined Geometric and Neural Network Approach to Generic Fault Diagnosis in Satellite Actuators and Sensors

    OpenAIRE

    Baldi, Pietro; Blanke, Mogens; Castaldi, Paolo; Mimmo, Nicola; Simani, Silvio

    2016-01-01

    This paper suggests a novel diagnosis scheme for detection, isolation and estimation of faults affecting satellite reaction wheels. Both spin rate measurements and actuation torque defects are dealt with. The proposed system consists of a fault detection and isolation module composed by a bank of residual filters organized in a generalized scheme, followed by a fault estimation module consisting of a bank of adaptive estimation filters. The residuals are decoupled from aerodynamic disturbance...

  6. Satellite Remote Sensing with Artificial Neural Network Modeling Techniques for Water Quality Monitoring

    Science.gov (United States)

    Kuo, Y. C.; Chen, C. F.

    2016-12-01

    The analyzed parameters of the water quality samples in Lake Nicaragua and Lake Managua include basic physical and chemical water quality parameters, nutrients, bacteria and zooplankton index, heavy metals and organic compounds in the sediments etc. 5 parameters are tested to assess lake eutrophication. To associate with satellite data, the analysis is aim to establish a set of mathematical transformations to convert the model spectra of satellite imagery reactions on water quality parameters and further to calculate the concentration of the parameters in both lakes. The sampling period took place during the rainy season. The high cloud-covered satellite imagery did not provide a completed available data for the analysis. Therefore, we used mathematical techniques to remake an image which contains a completed lake areas. Following by using linear equation to build the water quality models, the results suggested that the testing of chlorophyll in the model performance was the most accurate, and then the suspended solids, total phosphorus and total nitrogen. Fecal colon bacilli, of all parameters, has the worst performance in testing accuracy.

  7. Networked Learning and Network Science: Potential Applications to Health Professionals' Continuing Education and Development.

    Science.gov (United States)

    Margolis, Alvaro; Parboosingh, John

    2015-01-01

    Prior interpersonal relationships and interactivity among members of professional associations may impact the learning process in continuing medical education (CME). On the other hand, CME programs that encourage interactivity between participants may impact structures and behaviors in these professional associations. With the advent of information and communication technologies, new communication spaces have emerged that have the potential to enhance networked learning in national and international professional associations and increase the effectiveness of CME for health professionals. In this article, network science, based on the application of network theory and other theories, is proposed as an approach to better understand the contribution networking and interactivity between health professionals in professional communities make to their learning and adoption of new practices over time.

  8. Getting into networks and clusters: evidence from the Midi-Pyrenean Global Navigation Satellite Systems (GNSS) Collaboration Network

    NARCIS (Netherlands)

    Vicente, J.; Balland, P.M.A.; Brossard, O.

    2011-01-01

    This paper analyses clusters from collaborative knowledge relations. Focusing on the interface of clusters and networks contributes to a better understanding of collaboration, within and across places and cognitive domains. We propose an empirical analysis of the Midi-Pyrenean GNSS (Global Navigatio

  9. Developing A Large-Scale, Collaborative, Productive Geoscience Education Network

    Science.gov (United States)

    Manduca, C. A.; Bralower, T. J.; Egger, A. E.; Fox, S.; Ledley, T. S.; Macdonald, H.; Mcconnell, D. A.; Mogk, D. W.; Tewksbury, B. J.

    2012-12-01

    Over the past 15 years, the geoscience education community has grown substantially and developed broad and deep capacity for collaboration and dissemination of ideas. While this community is best viewed as emergent from complex interactions among changing educational needs and opportunities, we highlight the role of several large projects in the development of a network within this community. In the 1990s, three NSF projects came together to build a robust web infrastructure to support the production and dissemination of on-line resources: On The Cutting Edge (OTCE), Earth Exploration Toolbook, and Starting Point: Teaching Introductory Geoscience. Along with the contemporaneous Digital Library for Earth System Education, these projects engaged geoscience educators nationwide in exploring professional development experiences that produced lasting on-line resources, collaborative authoring of resources, and models for web-based support for geoscience teaching. As a result, a culture developed in the 2000s in which geoscience educators anticipated that resources for geoscience teaching would be shared broadly and that collaborative authoring would be productive and engaging. By this time, a diverse set of examples demonstrated the power of the web infrastructure in supporting collaboration, dissemination and professional development . Building on this foundation, more recent work has expanded both the size of the network and the scope of its work. Many large research projects initiated collaborations to disseminate resources supporting educational use of their data. Research results from the rapidly expanding geoscience education research community were integrated into the Pedagogies in Action website and OTCE. Projects engaged faculty across the nation in large-scale data collection and educational research. The Climate Literacy and Energy Awareness Network and OTCE engaged community members in reviewing the expanding body of on-line resources. Building Strong

  10. A Syntagm of Networked Educational Management: Case Study--University of Botswana

    Science.gov (United States)

    Uys, Philip

    2004-01-01

    Networked educational management has emerged as an effective, distributed management approach for managing educational technologies and e-learning in educational institutions. This management model has been developed during the writer's doctorate research and implementation of e-learning (also referred to as networked education) at Massey…

  11. A Syntagm of Networked Educational Management: Case Study--University of Botswana

    Science.gov (United States)

    Uys, Philip

    2004-01-01

    Networked educational management has emerged as an effective, distributed management approach for managing educational technologies and e-learning in educational institutions. This management model has been developed during the writer's doctorate research and implementation of e-learning (also referred to as networked education) at Massey…

  12. LEO星座网络动态源路由算法%Dynamic Source Routing Algorithm for LEO Satellite Networks

    Institute of Scientific and Technical Information of China (English)

    万鹏; 曹志刚; 王京林

    2007-01-01

    近年来,在低轨(LEO)卫星星座通信网络中采用网际协议(IP)路由算法的研究已经取得了一系列进展,文章论述了LEO星座通信网络的特点、拓扑结构和虚拟节点策略.在此基础上提出了基于泛洪路由的LEO星座动态源路由算法DSR-LSN(Dynamic Source Routing algorithm in LEO Satellite Networks),星座网络仿真表明,DSR-LSN算法具有网络路由状态稳定性好、时延小的优点.

  13. Performance Analysis of Anti-Interference Wireless Packet Networks for LEO Micro-Satellite with Adaptive Nulling Antenna Array

    Institute of Scientific and Technical Information of China (English)

    LIU Hai-tao; HAN Fang-jing; WAN Jian-wei

    2006-01-01

    Information integrity is key to successful operations in intricacy environments in the future, especially when strong interferences exist. This paper presents the design of a novel wireless packet network receiver system for Low Earth Orbit (LEO) micro-satellites with adaptive nulling antenna arrays. It uses three types of interference suppression in cascade: namely spread spectrum, adaptive array nulling, and transform domain filtering. This paper proposes a pilot channel-aided method in order to make full advantage of this arrangement, and analyzes its throughput and delay performance using the Markov chain model. Our results show that this method can achieve excellent delay and throughput performance: When the number of array antenna is 8, its throughput increase relative to the standard Slot-ALOHA protocol is 125 %.

  14. Maritime Aerosol Network as a Component of AERONET - First Results and Comparison with Global Aerosol Models and Satellite Retrievals

    Science.gov (United States)

    Smirnov, A.; Holben, B. N.; Giles, D. M.; Slutsker, I.; O'Neill, N. T.; Eck, T. F.; Macke, A.; Croot, P.; Courcoux, Y.; Sakerin, S. M.; Smyth, T. J.; Zielinski, T.; Zibordi, G.; Goes, J. I.; Harvey, M. J.; Quinn, P. K.; Nelson, N. B.; Radionov, V. F.; Duarte, C. M.; Remer, L. A.; Kahn, R. A.; Kleidman, R. G.; Gaitley, B. J.; Tan, Q.; Diehl, T. L.

    2011-01-01

    The Maritime Aerosol Network (MAN) has been collecting data over the oceans since November 2006. Over 80 cruises were completed through early 2010 with deployments continuing. Measurement areas included various parts of the Atlantic Ocean, the Northern and Southern Pacific Ocean, the South Indian Ocean, the Southern Ocean, the Arctic Ocean and inland seas. MAN deploys Microtops handheld sunphotometers and utilizes a calibration procedure and data processing traceable to AERONET. Data collection included areas that previously had no aerosol optical depth (AOD) coverage at all, particularly vast areas of the Southern Ocean. The MAN data archive provides a valuable resource for aerosol studies in maritime environments. In the current paper we present results of AOD measurements over the oceans, and make a comparison with satellite AOD retrievals and model simulations.

  15. Digital networks to aid research and education in Africa

    CERN Multimedia

    2005-01-01

    Around 120 participants were assembled over two days at CERN to discuss ways to bridge the digital divide with Africa. As part of efforts to implement the outcome of the first World Summit on the Information Society (WSIS), held in Geneva in 2003, CERN held the international workshop on Research and Education Networks in Africa, from 25 to 27 September. Organized by the United Nations University (UNU) in collaboration with the International Telecommunications Union (ITU) and CERN, this meeting was designed to promote scientific cooperation with and within Africa, through the development of networking infrastructure. Faster, reliable and more affordable Internet access is widely recognized as one of the key factors for enhancing research and education efforts in African academic and research institutions. For the first time, this workshop brought together representatives of all the key stakeholders: African academic and research institutions, international coordinators, funding agencies, grass-roots imple...

  16. An implementation of Software Defined Radios for federated aerospace networks: Informing satellite implementations using an inter-balloon communications experiment

    Science.gov (United States)

    Akhtyamov, Rustam; Cruz, Ignasi Lluch i.; Matevosyan, Hripsime; Knoll, Dominik; Pica, Udrivolf; Lisi, Marco; Golkar, Alessandro

    2016-06-01

    Novel space mission concepts such as Federated Satellite Systems promise to enhance sustainability, robustness, and reliability of current missions by means of in-orbit sharing of space assets. This new paradigm requires the utilization of several technologies in order to confer flexibility and re-configurability to communications systems among heterogeneous spacecrafts. This paper illustrates the results of the experimental demonstration of the value proposition of federated satellites through two stratospheric balloons interoperating with a tracking ground station through Commercial Off-The-Shelf Software Defined Radios (SDRs). The paper reports telemetry analysis and characterizes the communications network that was realized in-flight. Furthermore, it provides details on an in-flight anomaly experienced by one of the balloons, which was recovered through the use of the federated technology that has been developed. The anomaly experienced led to the early loss of the directional link from the ground station to the affected stratospheric balloon node after 15 min in flight. Nevertheless, thanks to the federated approach among the systems, the ground station was still able to retrieve the balloon's data in real time through the network system, for which the other balloon operated as a federated relay for 45 min in flight, uninterrupted. In other words, the federated approach to the system allowed triplicating the useful lifetime of the defective system, which would have not been possible to realize otherwise. Such anomaly coincidentally demonstrated the value of the federated approach to space systems design. The paper paves the way for future tests on space assets.

  17. Research progress of Group Key Management for Multi-layered Satellite Networks%多层卫星网络组密钥管理研究进展

    Institute of Scientific and Technical Information of China (English)

    余哲赋; 周海刚; 吴兆峰; 朱晓薇

    2012-01-01

    为保证多层卫星网络的通信安全,使用组密钥对通信进行加密是一个普遍而有效的方法。设计适合卫星网络的组密钥管理方案,是确保卫星通信安全的关键问题之一。本文介绍了多层卫星网络的概况,对现有多层卫星网络组密钥管理方案进行了分类,详细分析了几类典型的组密钥管理方案,指出了存在的问题,并对以后的研究方向作了展望。%Encrypting the contents of communication by using group key is an universal and effective method to ensure the security of communication in the Multi-layered satellite networks,and the design of a group key management scheme suitable for satellite networks is one of the key problems.This article provides an introduction of multi-layered satellite networks and classifies the routing protocols.This paper details several existing typical group key management schemes,and points out the corresponding disadvantages.The trends of group key management for multi-layered satellite networks are analyzed briefly.

  18. DIGITAL VIDEO BROADCAST RETURN CHANNEL VIA SATELLITE (DVB-RCS HUB FOR SATELLITE BASED E-LEARNING

    Directory of Open Access Journals (Sweden)

    N.G.Vasantha Kumar

    2011-02-01

    Full Text Available This paper discusses in-house designed and developed scale-down DVB-RCS hub along with the performance of the realized hub. This development is intended to support the Satellite Based e-Learning initiative in India. The scale-down DVB-RCS HUB is implemented around a single PC with other subsystems making it very cost effective and unique of its kind. This realization will drastically reduce the total cost of Satellite based Education Networks as very low cost commercially available Satellite Interactive Terminals (SITs complying to open standard could be used at remote locations. The system is successfully tested to work with a commercial SIT using a GEO satellite EDUSAT which is especially dedicated for satellite based e-Learning. The internal detail of the DVB-RCS Forward and Return Link Organization and how it manages the Satellite Interactive Terminals access to the satellite channel using MF-TDMA approach has been described.

  19. A new generic method for the semi-automatic extraction of river and road networks in low and mid-resolution satellite images

    Energy Technology Data Exchange (ETDEWEB)

    Grazzini, Jacopo [Los Alamos National Laboratory; Dillard, Scott [PNNL; Soille, Pierre [EC JRC

    2010-10-21

    This paper addresses the problem of semi-automatic extraction of road or hydrographic networks in satellite images. For that purpose, we propose an approach combining concepts arising from mathematical morphology and hydrology. The method exploits both geometrical and topological characteristics of rivers/roads and their tributaries in order to reconstruct the complete networks. It assumes that the images satisfy the following two general assumptions, which are the minimum conditions for a road/river network to be identifiable and are usually verified in low- to mid-resolution satellite images: (i) visual constraint: most pixels composing the network have similar spectral signature that is distinguishable from most of the surrounding areas; (ii) geometric constraint: a line is a region that is relatively long and narrow, compared with other objects in the image. While this approach fully exploits local (roads/rivers are modeled as elongated regions with a smooth spectral signature in the image and a maximum width) and global (they are structured like a tree) characteristics of the networks, further directional information about the image structures is incorporated. Namely, an appropriate anisotropic metric is designed by using both the characteristic features of the target network and the eigen-decomposition of the gradient structure tensor of the image. Following, the geodesic propagation from a given network seed with this metric is combined with hydrological operators for overland flow simulation to extract the paths which contain most line evidence and identify them with the target network.

  20. A Global Network for Educational Seismology ready to be used by everyone

    Science.gov (United States)

    Courboulex, F.; Bérenguer, J.; Tocheport, A.; Esnault, Y.; Larroque, C.; Jouffrey, F.; Nolet, G.; Deschamps, A.; Sladen, A.; Balestra, J.

    2013-12-01

    The French ';Sismos à l'Ecole' (Seismology at School or SaE) network currently comprises 60 seismic stations installed in French high schools: 40 inside France and 20 around the world (including the ';La Perouse' school in San Francisco). At this moment the network is mainly composed of 3-component digital stations with a broad-band sensor. All data have open access through a website (www.edusismo.org). Seismograms are used by students, teachers and researchers. In addition to this worldwide permanent backbone we are developing a secondary network with a simpler low-cost station: a basic digitizer with a one-component sensor that can be fixed to the wall of a school. The data of these stations are also freely available in real time and permit the development of student projects on seismology and seismic risk in a larger number of schools. The SaE network currently involves about 100 secondary teachers, as well as 20 researchers motivated to give students practical experience on a broad range of topics involving several disciplines in secondary education (geology, physics, geography, technology ...). The network is a starting point for more advanced educational activities such as the processing and interpretation of real data, quality assessment, and use of databases. In addition it promotes the awareness of seismic risk. We invite all the teachers and researchers around the world who would like to do experimental seismology with their students to use the data and the tools on the website that are in both a French and an English version. For the past 2 years, SaE has also been expanding through the European NERA project, which aim is to share data and experience in educational seismology in Europe and abroad. We shall soon add a new component 'Adopt a Mermaid' - in which classes can follow the new floating seismometers developed at Geoazur (see session S008) and deployed in the Mediterranean and Indian Ocean, try to predict their trajectories and learn about the

  1. Self-Assembled Core-Satellite Gold Nanoparticle Networks for Ultrasensitive Detection of Chiral Molecules by Recognition Tunneling Current.

    Science.gov (United States)

    Zhang, Yuanchao; Liu, Jingquan; Li, Da; Dai, Xing; Yan, Fuhua; Conlan, Xavier A; Zhou, Ruhong; Barrow, Colin J; He, Jin; Wang, Xin; Yang, Wenrong

    2016-05-24

    Chirality sensing is a very challenging task. Here, we report a method for ultrasensitive detection of chiral molecule l/d-carnitine based on changes in the recognition tunneling current across self-assembled core-satellite gold nanoparticle (GNP) networks. The recognition tunneling technique has been demonstrated to work at the single molecule level where the binding between the reader molecules and the analytes in a nanojunction. This process was observed to generate a unique and sensitive change in tunneling current, which can be used to identify the analytes of interest. The molecular recognition mechanism between amino acid l-cysteine and l/d-carnitine has been studied with the aid of SERS. The different binding strength between homo- or heterochiral pairs can be effectively probed by the copper ion replacement fracture. The device resistance was measured before and after the sequential exposures to l/d-carnitine and copper ions. The normalized resistance change was found to be extremely sensitive to the chirality of carnitine molecule. The results suggested that a GNP networks device optimized for recognition tunneling was successfully built and that such a device can be used for ultrasensitive detection of chiral molecules.

  2. Planning alternative organizational frameworks for a large scale educational telecommunications system served by fixed/broadcast satellites

    Science.gov (United States)

    Walkmeyer, J.

    1973-01-01

    This memorandum explores a host of considerations meriting attention from those who are concerned with designing organizational structures for development and control of a large scale educational telecommunications system using satellites. Part of a broader investigation at Washington University into the potential uses of fixed/broadcast satellites in U.S. education, this study lays ground work for a later effort to spell out a small number of hypothetical organizational blueprints for such a system and for assessment of potential short and long term impacts. The memorandum consists of two main parts. Part A deals with subjects of system-wide concern, while Part B deals with matters related to specific system components.

  3. Handbook of satellite applications

    CERN Document Server

    Madry, Scott; Camacho-Lara, Sergio

    2017-01-01

    The first edition of this ground breaking reference work was the most comprehensive reference source available about the key aspects of the satellite applications field. This updated second edition covers the technology, the markets, applications and regulations related to satellite telecommunications, broadcasting and networking—including civilian and military systems; precise satellite navigation and timing networks (i.e. GPS and others); remote sensing and meteorological satellite systems. Created under the auspices of the International Space University based in France, this brand new edition is now expanded to cover new innovative small satellite constellations, new commercial launching systems, innovation in military application satellites and their acquisition, updated appendices, a useful glossary and more.

  4. Design of Geodetic SVLBI Satellite Orbit and Its Tracking Network%SVLBI用于大地测量的卫星轨道及其跟踪网设计

    Institute of Scientific and Technical Information of China (English)

    魏二虎; 刘经南; KULKARNI M.N.; FREY Sándor

    2008-01-01

    SVLBI (space very long baseline interferometry) has some important potential applications in geodesy and geodynam- ics, for which one of the most difficult tasks is to precisely determine the orbit of an SVLBI satellite. This work studies several technologies that will possibly be able to determine the orbit of a space VLBI satellite. Then, according to the types and charac- teristics of the satellite and the requirements for geodetic study and the geometry of the GNSS (GPS, GALILEO) satellite to track the space VLBI satellite, the six Keplerian elements of the SVLBI satellite (TEST-SVLBI) are determined. A program is designed to analyze the coverage area of space of different altitudes by the stations of the network, with which the tracking network of TEST-SVLBI is designed. The efficiency of tracking TEST-SVLBI by the network is studied, and the results are presented.

  5. 移动卫星网络中卫星切换调度研究%Research on the Handover Scheduling in Mobile Satellite Communication Networks

    Institute of Scientific and Technical Information of China (English)

    吴兆峰; 胡谷雨; 金凤林

    2015-01-01

    针对卫星切换调度问题,提出了一种最大服务时长切换调度算法。该算法利用了现有的GPS基础设施和卫星网络中卫星的多样性(即在任意时刻多颗卫星覆盖相同的区域),减少了用户在通信过程中的切换次数,从而最终降低了用户的掉话率,实现了用户在低轨( LEO)卫星网络中实时高效的切换。在Iridium卫星网络中的仿真结果验证了该算法的有效性。%A new satellite handover scheduling algorithm based on the maximum residual service time was proposed. The algorithm exploits both global positioning system ( GPS) infrastructure and satellite diversi-ty, providing a simple and real-time handover management in low earth orbit ( LEO) satellite networks to minimize the expected number of satellite handovers. It reduces the users' call drop probability ultimate-ly. Simulations were carried out on the typical Iridium satellite network and the simulation results corrob-orate the advantages gained by the proposed algorithm.

  6. Method of Performance-Aware Security of Unicast Communication in Hybrid Satellite Networks

    Science.gov (United States)

    Roy-Chowdhury, Ayan (Inventor); Baras, John S. (Inventor)

    2014-01-01

    A method and apparatus utilizes Layered IPSEC (LES) protocol as an alternative to IPSEC for network-layer security including a modification to the Internet Key Exchange protocol. For application-level security of web browsing with acceptable end-to-end delay, the Dual-mode SSL protocol (DSSL) is used instead of SSL. The LES and DSSL protocols achieve desired end-to-end communication security while allowing the TCP and HTTP proxy servers to function correctly.

  7. A global network for the control of snail-borne disease using satellite surveillance and geographic information systems.

    Science.gov (United States)

    Malone, J B; Bergquist, N R; Huh, O K; Bavia, M E; Bernardi, M; El Bahy, M M; Fuentes, M V; Kristensen, T K; McCarroll, J C; Yilma, J M; Zhou, X N

    2001-04-27

    At a team residency sponsored by the Rockefeller Foundation in Bellagio, Italy, 10-14 April 2000 an organizational plan was conceived to create a global network of collaborating health workers and earth scientists dedicated to the development of computer-based models that can be used for improved control programs for schistosomiasis and other snail-borne diseases of medical and veterinary importance. The models will be assembled using GIS methods, global climate model data, sensor data from earth observing satellites, disease prevalence data, the distribution and abundance of snail hosts, and digital maps of key environmental factors that affect development and propagation of snail-borne disease agents. A work plan was developed for research collaboration and data sharing, recruitment of new contributing researchers, and means of access of other medical scientists and national control program managers to GIS models that may be used for more effective control of snail-borne disease. Agreement was reached on the use of compatible GIS formats, software, methods and data resources, including the definition of a 'minimum medical database' to enable seamless incorporation of results from each regional GIS project into a global model. The collaboration plan calls for linking a 'central resource group' at the World Health Organization, the Food and Agriculture Organization, Louisiana State University and the Danish Bilharziasis Laboratory with regional GIS networks to be initiated in Eastern Africa, Southern Africa, West Africa, Latin America and Southern Asia. An Internet site, www.gnosisGIS.org, (GIS Network On Snail-borne Infections with special reference to Schistosomiasis), has been initiated to allow interaction of team members as a 'virtual research group'. When completed, the site will point users to a toolbox of common resources resident on computers at member organizations, provide assistance on routine use of GIS health maps in selected national disease control

  8. Satellite-delivered medical education and training for central Europe: a TEMPUS project. Trans-European Mobility Programme for University Students.

    Science.gov (United States)

    Young, H L

    1996-01-01

    This paper reports the experience gained in delivering continuing and postgraduate medical education by satellite to update medical teachers in Central Europe. An infrastructure of receiving sites was established in the Czech Republic, Slovakia, Poland and Hungary. The sites participated in regular, live interactive broadcasts on a range of medical education topics. Over three years a network of sites was established incrementally and a national coordinator identified for each country, who fed back from national coordinating committees to an overall steering body. In the final year a formal evaluation revealed high satisfaction levels and maintenance of activity during the grant period. The major problems related to a lack of telephone lines to facilitate interactivity, the timing of the programmes, and the need for training in medical English language. Video libraries were established, and the majority continued to be active at the end of the project grant. Material was incorporated into both undergraduate and postgraduate education. It is calculated that continuing professional development can be delivered at less than 18 ECU per participant per country.

  9. An Introduction to the UK Polar Network: Education and Outreach

    Science.gov (United States)

    Hendry, K.; Irvine, E.; Mugford, R.; Freeman, H.; Baker, N.; Thomas, L.; Rye, C.; Cheshire, J.

    2007-12-01

    The UK Polar Network is the UK branch of the IPY Youth Steering Committee, an endorsed IPY Project, and the Association of Polar Early Career Scientists (APECS). We have two aims in the UKPN: (1) to provide a network for early career polar researchers working in the UK and (2) to carry out education and outreach activities in UK schools, science festivals and through our website. The Education and Outreach working group is involved in organising programs for a range of age groups including engaging activities for primary and secondary school children, information packs on careers and gap year ideas to school leavers and undergraduate students. The intention is, as far as possible, to keep these events free through fundraising. In addition we aim to provide funding for UK polar researchers to attend national networking days and international IPY conferences to present their work, and are involved with organising workshops at these events. In addition, our website is being developed to provide discussion boards, careers information for polar researchers, as well as information for the public, photos and blogs from polar researchers in the field.

  10. Routing Technology Research for LEO Satellite Constellation Networks%低轨道卫星星座网络路由研究

    Institute of Scientific and Technical Information of China (English)

    蒋文娟; 宗鹏

    2011-01-01

    Because of the particular features of LEO satellite networks, such as dynamic topology, non-homogeneous traffic distribution,limited power and processing, new satellite routing approaches should be developed. How to design simple and efficient routing algorithm becomes the hot topic of LEO satellite networks. Analyze the characteristics of LEO satellite networks, and then survey the cunrrent LEO satellite routing algorithms classified with the geometric model, handoff and onboard processing capability. Typical algorithms of each class are presented and their advantages, suitable environment and shortcomings with a detailed comprehensive comparison are discussed. The end of the paper points out the future research field for LFO satellite routing prob1em.%拓扑时变性、承载业务分布不均衡以及星上资源有限,使得设计新的低轨道卫星星座网络路由算法迫在眉睫.如何设计简单、高效的低轨道卫星星座路由成为当前卫星网络研究的热点问题.深入剖析了LEO卫星网络的特点,从几何模型、切换以及星上处理能力三个视角出发,分类综述了LEO卫星路由算法,阐述了各类路由的典型算法,讨论了每种算法的优点和适用环境,剖析了其中存在的问题,并对它们进行了综合对比.最后指出了LEO卫星路由算法进一步的研究方向.

  11. Linked to Innovation: Shaping an Innovative Climate through Network Intentionality and Educators' Social Network Position

    Science.gov (United States)

    Moolenaar, Nienke M.; Daly, Alan J.; Cornelissen, Frank; Liou, Yi-Hwa; Caillier, Stacey; Riordan, Rob; Wilson, Kelly; Cohen, N. Andrew

    2014-01-01

    This study investigates whether educators' cognitive and structural social capital is associated with perceptions of innovative climate in charter schools. We explore a new concept to assess educators' cognitive social capital, namely network intentionality, meaning the extent to which an educator is intentional in connecting and…

  12. SHADOZ (Southern Hemisphere ADditional OZonesondes): An Ozonesonde Network for Satellite Validation, Climatology and Modeling

    Science.gov (United States)

    Thompson, Anne M.; Witte, Jacquelyn C.; Schmidlin, Francis J.; Oltmans, Samuel J.; McPeters, Richard D.; Einaudi, Franco (Technical Monitor)

    2000-01-01

    In the past 5 years, new tropical ozone data products have been developed from TOMS and other satellites, During this period, global chemical-transport models have been used for ozone assessment studies. However, there has been a lack of independent ozone profiles in the tropics for evaluation of the data sets and models. In 1998, NASA's Goddard Space Flight Center, Wallops Flight Facility and NOAA's CMDL (Climate Monitoring and Diagnostics Lab), began a 2-year project to collect a consistent data set by augmenting ozonesonde launches at southern hemisphere tropical sites The measurements are available to the scientific community at a single electronic location - the SHADOZ website at NASA/Goddard: http://code9l6.gsfc.nasa.gov/Data services/Shadoz/shadoz hmpg2.html. Stations in SHADOZ include four islands in the Pacific: Fiji, Tahiti, San Cristobal (Galapagos) and American Samoa. Two sites are at and in the Atlantic: Natal (Brazil) and Ascension Island. Three other sites span Africa (Nairobi and Irene, South Africa) and the Indian Ocean (Reunion Island and Watukosek in Java, Indonesia). All SHADOZ sites are using ECC-type sondes, with the conversion from JMD sondes at Java in 1999, but there are variations in sonde preparation technique and data processing. During the 1998-1999 period, more than 550 sondes were incorporated into the SHADOZ data base. Examples from these measurements illustrate the tropical wave-one pattern in total ozone which is easily detectable by satellite. They also show that the wave-one pattern appears to be in the troposphere, as assumed in creating the modified-residual tropospheric ozone data product from TOMS. SHADOZ will add data from intensive field campaigns from time to time. Recent contributions to the SHADOZ archive are from the INDOEX (Indian Ocean Experiment January-March 1999)sondes at the Maldives (5N, 73E) and 27 sondes on the US NOAA oceanographic vessel, the FIN Ronald H Brown between Virginia (US) and Mauritius via Cape

  13. Validation of satellite data through the remote sensing techniques and the inclusion of them into agricultural education pilot programs

    Science.gov (United States)

    Papadavid, Georgios; Kountios, Georgios; Bournaris, T.; Michailidis, Anastasios; Hadjimitsis, Diofantos G.

    2016-08-01

    Nowadays, the remote sensing techniques have a significant role in all the fields of agricultural extensions as well as agricultural economics and education but they are used more specifically in hydrology. The aim of this paper is to demonstrate the use of field spectroscopy for validation of the satellite data and how combination of remote sensing techniques and field spectroscopy can have more accurate results for irrigation purposes. For this reason vegetation indices are used which are mostly empirical equations describing vegetation parameters during the lifecycle of the crops. These numbers are generated by some combination of remote sensing bands and may have some relationship to the amount of vegetation in a given image pixel. Due to the fact that most of the commonly used vegetation indices are only concerned with red-near-infrared spectrum and can be divided to perpendicular and ratio based indices the specific goal of the research is to illustrate the effect of the atmosphere to those indices, in both categories. In this frame field spectroscopy is employed in order to derive the spectral signatures of different crops in red and infrared spectrum after a campaign of ground measurements. The main indices have been calculated using satellite images taken at interval dates during the whole lifecycle of the crops by using a GER 1500 spectro-radiomete. These indices was compared to those extracted from satellite images after applying an atmospheric correction algorithm -darkest pixel- to the satellite images at a pre-processing level so as the indices would be in comparable form to those of the ground measurements. Furthermore, there has been a research made concerning the perspectives of the inclusion of the above mentioned remote satellite techniques to agricultural education pilot programs.

  14. Instructional Materials Thesaurus for Special Education, Second Edition. Special Education IMC/RMC Network.

    Science.gov (United States)

    Oldsen, Carl F.; And Others

    The thesaurus delineates the standard terminology used to index and retrieve instructional materials for exceptional children in the Special Education Instructional Materials Center/Regional Media Centers Network. The thesaurus is presented in three formats: an alphabetical listing (word by word rather than letter by letter), a rotated index, and…

  15. The Effects of Financial Education and Networks on Business Students' Financial Literacy

    Science.gov (United States)

    Chung, Yunhyung; Park, Youngkyun

    2014-01-01

    This study investigates the joint effects of financial education and educational networks on students' financial literacy. With a sample (N = 105) of senior students in a business college, the study finds that not only financial education, but also strong networks with professors, are positively related to the financial literacy of business…

  16. Social Networks as Learning Environments for Higher Education

    Directory of Open Access Journals (Sweden)

    J.A.Cortés

    2014-09-01

    Full Text Available Learning is considered as a social activity, a student does not learn only of the teacher and the textbook or only in the classroom, learn also from many other agents related to the media, peers and society in general. And since the explosion of the Internet, the information is within the reach of everyone, is there where the main area of opportunity in new technologies applied to education, as well as taking advantage of recent socialization trends that can be leveraged to improve not only informing of their daily practices, but rather as a tool that explore different branches of education research. One can foresee the future of higher education as a social learning environment, open and collaborative, where people construct knowledge in interaction with others, in a comprehensive manner. The mobility and ubiquity that provide mobile devices enable the connection from anywhere and at any time. In modern educational environments can be expected to facilitate mobile devices in the classroom expansion in digital environments, so that students and teachers can build the teaching-learning process collectively, this partial derivative results in the development of draft research approved by the CONADI in “Universidad Cooperativa de Colombia”, "Social Networks: A teaching strategy in learning environments in higher education."

  17. FCJ-140 Radio Feeds, Satellite Feeds, Network Feeds: Subjectivity Across the Straits of Gibraltar.

    Directory of Open Access Journals (Sweden)

    Nicholas Knouf

    2012-07-01

    Full Text Available This paper engages with the practices surrounding the two fadaiat encounters that took place simultaneously in Spain and Morocco in the summers of 2004 and 2005 (see http://fadaiat.net/ .  The fadaiat project focused on the question of immigration to Europe, specifically from northern Africa, and the ‘Fortress Europe’ responses by European Union governments.  Participants in fadaiat included academic scholars, free software developers, artists, and activists, forming a meta-network that created bridges across disparate communities and practices.  In particular, the participation of the Spanish collective hackitectura was key; they describe themselves as a ‘posse of architects, hackers and social activists experimenting in the merging territories of recombining spatial cyborgs composed by physical spaces, ICT networks and bodies’.  hackitectura led the development of both a temporary civil, non-commercial wireless link across the straits of Gibraltar between Tarifa, Spain and Tangier, Morocco, as well as an entirely free software audio/video streaming system, that enabled participants on both sides to come together independently of the restrictions normally placed on such movement by immigration laws.The importance of free software for fadaiat extends beyond its purely instrumental use as an agent for disrupting state control.  Indeed, the imagery of computation and free software – networks, links, patches, nodes, penguins – pervades the documentation of the project.  Rave parties simulcast across the straits are as important as the discussions and software produced.  I suggest that this can be understood as developing new forms of subjectivity, in the sense given by Felix Guattari, and therefore link the fadaiat project to earlier pirate radio practices, especially Radio Alice in Bologna, Italy, in which Guattari was involved.

  18. Satellite mission Aeronomy of Ice in the Mesosphere (AIM) partners with formal and informal education programs to study clouds on the edge of space

    Science.gov (United States)

    Robinson, D. Q.; Maggi, B. H.

    2004-12-01

    The satellite-based research mission "Aeronomy of Ice In the Mesosphere" (AIM), has developed an exciting partnership of formal and informal education programs that will connect students and the public to the unique scientific aspects of the mission. The AIM satellite mission is dedicated to providing a scientific basis for understanding why Polar Mesospheric Clouds (PMCs) form and vary. PMCs are sometimes known as Noctilucent Clouds (NLCs) or "night shinning" clouds because of their visibility at dawn and dusk. The visible manifestation of PMCs provides a unique opportunity for Education and Public Outreach. The AIM outreach programs will utilize the beautiful images of "clouds on the edge of space" as a tool to motivate students and the public to increase their knowledge and understanding about issues surrounding changes in our atmosphere. In an effort to provide formal and informal outreach opportunities worldwide, AIM has developed a partnership with the GLOBE program. GLOBE is a network of schools, science centers, and clubs from over 105 countries where participants collect scientific data according to precise protocols and enter the data into a central database allowing both scientists and students to utilize the data. The collaboration between AIM and GLOBE will involve participants in collecting and utilizing NLC data worldwide. This partnership will provide a mechanism for sustaining AIM education opportunities for both formal and informal education venues in the future. Included in the formal education component of AIM outreach is the implementation of two educator workshops that will establish partnerships between the mission and classrooms nationwide. The educator workshops will be held in Alaska due to the optimal location for viewing NLCs. Participants attending the workshops will be chosen from a national pool allowing teachers working with students in southern latitudes an opportunity to experience the excitement of working with data that can only

  19. An Interactive Network Laboratory for Electronic Engineering Education

    Institute of Scientific and Technical Information of China (English)

    Shao-Chun Fan; Jian-Jun Jiang; Wen-Qing Liu

    2007-01-01

    The advantage of the network laboratory is the better flexibility of lab experiments by allowing remote control from different locations at a freely chosen time. In engineering education, the work should not only be focused on the technical realization of virtual or remote access experiments, but also on the achievement of its pedagogical goals. In this paper, an interactive laboratory is introduced which is based on the online tutoring system, virtual and remote access experiments. It has been piloted in the Department of Electronic Science and Technology, HUST. Some pedagogical issues for electronic engineering laboratory design, the development of a multi-server-based distributed architecture for the reduction of network latency and implementations of the function module are presented. Finally, the system is proved valid by an experiment.

  20. Educational Designs Supporting Student Engagement Through Network Project Studies

    DEFF Research Database (Denmark)

    Nielsen, Jørgen Lerche

    2016-01-01

    , developed from the traditions of organizing university studies through student-driven project work and problem-driven learning approaches, which have been developed at the Danish universities of Roskilde and Aalborg as early as from the beginning of the 1970s. Specific educational designs integrating...... digital media are discussed, especially focusing on student engagement and the implications of organizing the pedagogical practice as networked project work. The discussions are based on the author’s experiences during 16 years of teaching and supervising at the Danish Master’s Program of ICT and Learning...... (MIL), where students conduct blended learning study in groups within a networked learning structure. In problem-oriented learning and teaching, teachers act as well as teachers and as supervisors of students’ projects. This challenges the traditional teacher role, and it is crucial for a teacher...

  1. The Network for Astronomy in Education in Southwest New Mexico

    Science.gov (United States)

    Neely, B.

    1998-12-01

    The Network for Astronomy in Education was organized to use astronomy as a motivational tool to teach science methods and principles in the public schools. NFO is a small private research observatory, associated with the local University, Western New Mexico. We started our program in 1996 with an IDEA grant by introducing local teachers to the Internet, funding a portable planetarium (Starlab) for the students, and upgrading our local radio linked computer network. Grant County is a rural mining and ranching county in Southwest New Mexico. It is ethnically diverse and has a large portion of the population below the poverty line. It's dryness and 6000' foot elevation, along with dark skies, suite it to the appreciation of astronomy. We now have 8 local schools involved in astronomy at some level. Our main programs are the Starlab and Project Astro, and we will soon install a Sidewalk Solar System in the center of Silver City.

  2. Network management paradigm in education as a component of information society

    Directory of Open Access Journals (Sweden)

    O. O. Kolesnic

    2014-05-01

    Full Text Available Network organization has always existed, but that today information technologies create the material basis for the penetration of this type of structure in all areas. This allows to interpret the formation of a network management paradigm as one of the innovative processes of information society . The effects on the development of the virtual environment in the form of a network society leads to the fact that traditional forms of management education change it its own characteristics and there are conditions for the effective use of new forms of governance, it is connected with the network nature of education as a space object management. In practice, the process of modernization of the existing network of educational institutions and organizations that generally means use of information technology and the significant decline in the share of traditional hierarchical forms of control by increasing the share of collective polyarchical forms. Today, the introduction of a network management paradigm of education is performed primarily as a stochastic process of entering educational institutions in the space of network society. The main methodological shortcomings of network management in education is the lack of understanding of its specificity in the context of providing social impact of educational activities. Promising area of implementation of network management in education is the use of targeted management practices that focus on the development of very specific forms of network co­operation in education.

  3. Using actor-network theory to study an educational situation: an ...

    African Journals Online (AJOL)

    Using actor-network theory to study an educational situation: an example from information systems at a technikon. ... Actor-network theory allows a researcher to analyse a complex social setting involving both human and non-human actors.

  4. Route strategy of satellite network in GNSS based on topology evolution law

    Institute of Scientific and Technical Information of China (English)

    Xianqing Yi; Zhenwei Hou; Tao Zhong; Yaohong Zhang; Zhili Sun

    2014-01-01

    As each type of satel ite network has different link features, its data transmission must be designed based on its link features to improve the efficiency of data transferring. The transmission of navigation integrated services information (NISI) in a global navigation satel ite system (GNSS) with inter-satel ite links (ISLs) is studied by taking the real situation of inter-satel ite communication links into account. An on-demand computing and buffering centralized route strategy is proposed based on dynamic grouping and the topology evolution law of the GNSS network within which the satel ite nodes are operated in the manner of dynamic grouping. Dynamic grouping is based on satel ites spatial relationships and the group role of the satel ite node changes by turns due to its spatial relationships. The route strategy provides significant advantages of high efficiency, low complexity, and flexi-ble configuration, by which the established GNSS can possess the features and capabilities of feasible deployment, efficient trans-mission, convenient management, structural invulnerability and flexible expansion.

  5. Research on Satellite Network Secure Routing Objectives%卫星网络安全路由目标研究

    Institute of Scientific and Technical Information of China (English)

    周星; 刘军; 董春冻; 张玉静

    2013-01-01

    确定合适的安全目标是对协议进行安全增强的前提,针对目前对卫星网络路由协议的安全目标研究不充分,没有统一的安全目标的现状,文中对卫星网络路由协议的安全目标进行研究,并提出改进的安全路由目标.通过在现有plausible routing即路由可达的目标基础上对路由消息进行认证性、机密性等保护以增强安全性,并用串空间将所提目标形象地表示.分析表明,改进的安全目标,克服了原plausible routing目标的部分不足,增进了路由协议的安全性.文中提出的安全目标进一步从形式化的方式上对卫星网络路由协议的安全性进行了研究,为以后的研究提供了一定的基础.%It used to be the foremost thing to give a proper secure objectives so as to make a protocol safer,as there has been no sufficient research on secure objectives and no secure objectives is well accepted so far,researched the satellite network secure routing objectives,and gave improved secure routing objectives.Improved the security by doing authentication and confidentiality protection on the basis of plausible routing also named routing reachable,and illustrated it using strand space.Analysis showed the improved objectives solved some drawbacks appeared in the plausible routing,and enhanced the security of routing protocol.The proposed secure objectives further researched satellite network routing protocol formally,offering some fundamentals for later research.

  6. Verification of the Usefulness of the Trimble Rtx Extended Satellite Technology with the Xfill Function in the Local Network Implementing Rtk Measurements

    Science.gov (United States)

    Siejka, Zbigniew

    2014-12-01

    The paper presents the method of satellite measurements, which gives users the ability of GNSS continuous precise positioning in real time, even in the case of short interruptions in receiving the correction of the local ground system of measurements support. The proposed method is a combination of two satellite positioning technologies RTN GNSS and RTX Extended. In technology RTX Extended the xFill function was used for precise positioning in real time and in the local reference system. This function provides the ability to perform measurement without the need for constant communication with the ground support satellite system. Test measurements were performed on a test basis located in Krakow, and RTN GNSS positioning was done based on the national network of reference stations of the ASGEUPOS. The solution allows for short (up to 5 minutes) interruptions in radio or internet communication. When the primary stream of RTN correction is not available, then the global corrections Trimble xFill broadcasted by satellite are used. The new technology uses in the real-time data from the global network of tracking stations and contributes significantly to improving the quality and efficiency of surveying works. At present according to the authors, technology Trimble CenterPoint RTX can guarantee repeatability of measurements not worse than 3.8 cm (Trimble Survey Division, 2012). In the paper the comparative analysis of measurement results between the two technologies was performed: RTN carried out in the classic way, which was based on the corrections of the terrestrial local network of the Polish system of active geodetic network (ASG-EUPOS) and RTK xFill technology. The results were related to the data of test network, established as error free. The research gave satisfactory results and confirmed the great potential of the use of the new technology in the geodetic work realization. By combining these two technologies of GNSS surveying the user can greatly improve the

  7. Storage Area Network Implementation on an Educational Institute Network Computer Networking and Communication

    CERN Document Server

    Osama, Safarini

    2011-01-01

    the storage infrastructure is the foundation on which information relies and therefore must support a company's business objectives and business model. In this environment, simply deploying more and faster storage devices is not enough; a new kind of infrastructure is needed, one that provides more enhanced network availability, data accessibility, and system manageability than is provided by today's infrastructure. The SAN meets this challenge. The SAN liberates the storage device, so it is not on a particular server bus, and attaches it directly to the network. In other words, storage is externalized and functionally distributed across the organization. The SAN also enables the centralizing of storage devices and the clustering of servers, which makes for easier and less expensive administration. So the idea is to create an intelligent SAN infrastructure that stretches to meet increased demands, allows highly available and heterogeneous access to expanding information.

  8. NETWORKING OF EDUCATIONAL INSPECTION: THE "INSPECTIO" PLATFORM IN ANDALUSIA

    Directory of Open Access Journals (Sweden)

    Pedro Ángel Luna Ariza

    2014-12-01

    Full Text Available A look to the future of Educational Inspection demands to put the attention in the internal processes of organization and functioning. The model of inspector which work is realized to the margin of the rest of his companions has expired. The current tools that provide to us the new technologies of the information and the communication facilitate our daily occupation and improve the possibilities of coordination in the equipment and services. The possibilities to work in network of the inspectors of education in Andalusia using Inspectio Platform it is a good example of it. After a normative foundation and a conceptual approximation, we try to explain this tool, using a descriptive and practical methodology.

  9. Changes in satellite-derived impervious surface area at US historical climatology network stations

    Science.gov (United States)

    Gallo, Kevin; Xian, George

    2016-10-01

    The difference between 30 m gridded impervious surface area (ISA) between 2001 and 2011 was evaluated within 100 and 1000 m radii of the locations of climate stations that comprise the US Historical Climatology Network. The amount of area associated with observed increases in ISA above specific thresholds was documented for the climate stations. Over 32% of the USHCN stations exhibited an increase in ISA of ⩾20% between 2001 and 2011 for at least 1% of the grid cells within a 100 m radius of the station. However, as the required area associated with ISA change was increased from ⩾1% to ⩾10%, the number of stations that were observed with a ⩾20% increase in ISA between 2001 and 2011 decreased to 113 (9% of stations). When the 1000 m radius associated with each station was examined, over 52% (over 600) of the stations exhibited an increase in ISA of ⩾20% within at least 1% of the grid cells within that radius. However, as the required area associated with ISA change was increased to ⩾10% the number of stations that were observed with a ⩾20% increase in ISA between 2001 and 2011 decreased to 35 (less than 3% of the stations). The gridded ISA data provides an opportunity to characterize the environment around climate stations with a consistently measured indicator of a surface feature. Periodic evaluations of changes in the ISA near the USHCN and other networks of stations are recommended to assure the local environment around the stations has not significantly changed such that observations at the stations may be impacted.

  10. The use of Social Networks for Educational Purposes - Case Study: Polytechnic Nikola Tesla in Gospic

    Directory of Open Access Journals (Sweden)

    Aleksandar Skendžić

    2017-08-01

    Full Text Available Social networks are a way of mass communication between users, but they are also applied for educational purposes. The aim of this paper is to analyze the way that students use social networks for educational purposes, to find out how students come to information, do they use social networks for access to information related to teaching and exams, and what they think about the quality of information obtained from social networks. The relationship between the use of social networks for educational purposes and demographic indicators is examined. χ2 test for testing independence of the two characteristics was conducted.

  11. Network global navigation satellite system survey to harmonize water-surface elevation data for the Rainy River Basin

    Science.gov (United States)

    Ziegeweid, Jeffrey R.; Silliker, R. Jason; Densmore, Brenda K.; Krahulik, Justin

    2016-08-15

    Continuously recording water-level streamgages in Rainy Lake and Namakan Reservoir are used to regulate water levels according to rule curves established in 2000 by the International Joint Commission; however, water levels at streamgages were referenced to a variety of vertical datums, confounding efforts to model the flow of water through the system, regulate water levels during periods of high inflow, and evaluate the effectiveness of the rule curves. In October 2014, the U.S. Geological Survey, Natural Resources Canada, International Joint Commission, and National Park Service began a joint field study with the goal of obtaining precise elevations referenced to a uniform vertical datum for all reference marks used to set water levels at streamgages throughout Rainy Lake and Namakan Reservoir. This report was prepared by the U.S. Geological Survey in cooperation with Natural Resources Canada, International Joint Commission, and National Park Service.Three field crews deployed Global Navigation Satellite System receivers statically over 16 reference marks colocated with active and discontinued water-level streamgages throughout Rainy River, Rainy Lake, Namakan Reservoir, and select tributaries of Rainy Lake and Namakan Reservoir. A Global Navigation Satellite System receiver also was deployed statically over a National Geodetic Survey cooperative base network control station for use as a quality-control reference mark. Satellite data were collected simultaneously during a 5-day period and processed independently by the U.S. Geological Survey and Natural Resources Canada to obtain accurate positioning and elevations for the 17 surveyed reference marks. Processed satellite data were used to convert published water levels to elevations above sea level referenced to the Canadian Geodetic Vertical Datum of 2013 in order to compare water-surface elevations referenced to a uniform vertical datum throughout the study area. In this report, an “offset” refers to the

  12. Investigating the Potential of Deep Neural Networks for Large-Scale Classification of Very High Resolution Satellite Images

    Science.gov (United States)

    Postadjian, T.; Le Bris, A.; Sahbi, H.; Mallet, C.

    2017-05-01

    Semantic classification is a core remote sensing task as it provides the fundamental input for land-cover map generation. The very recent literature has shown the superior performance of deep convolutional neural networks (DCNN) for many classification tasks including the automatic analysis of Very High Spatial Resolution (VHR) geospatial images. Most of the recent initiatives have focused on very high discrimination capacity combined with accurate object boundary retrieval. Therefore, current architectures are perfectly tailored for urban areas over restricted areas but not designed for large-scale purposes. This paper presents an end-to-end automatic processing chain, based on DCNNs, that aims at performing large-scale classification of VHR satellite images (here SPOT 6/7). Since this work assesses, through various experiments, the potential of DCNNs for country-scale VHR land-cover map generation, a simple yet effective architecture is proposed, efficiently discriminating the main classes of interest (namely buildings, roads, water, crops, vegetated areas) by exploiting existing VHR land-cover maps for training.

  13. Galileo satellite antenna modeling

    Science.gov (United States)

    Steigenberger, Peter; Dach, Rolf; Prange, Lars; Montenbruck, Oliver

    2015-04-01

    The space segment of the European satellite navigation system Galileo currently consists of six satellites. Four of them belong to the first generation of In-Orbit Validation (IOV) satellites whereas the other two are Full Operational Capability (FOC) satellites. High-precision geodetic applications require detailed knowledge about the actual phase center of the satellite and receiver antenna. The deviation of this actual phase center from a well-defined reference point is described by phase center offsets (PCOs) and phase center variations (PCVs). Unfortunately, no public information is available about the Galileo satellite antenna PCOs and PCVs, neither for the IOV, nor the FOC satellites. Therefore, conventional values for the IOV satellite antenna PCOs have been adopted for the Multi-GNSS experiment (MGEX) of the International GNSS Service (IGS). The effect of the PCVs is currently neglected and no PCOs for the FOC satellites are available yet. To overcome this deficiency in GNSS observation modeling, satellite antenna PCOs and PCVs are estimated for the Galileo IOV satellites based on global GNSS tracking data of the MGEX network and additional stations of the legacy IGS network. Two completely independent solutions are computed with the Bernese and Napeos software packages. The PCO and PCV values of the individual satellites are analyzed and the availability of two different solutions allows for an accuracy assessment. The FOC satellites are built by a different manufacturer and are also equipped with another type of antenna panel compared to the IOV satellites. Signal transmission of the first FOC satellite has started in December 2014 and activation of the second satellite is expected for early 2015. Based on the available observations PCO estimates and, optionally PCVs of the FOC satellites will be presented as well. Finally, the impact of the new antenna model on the precision and accuracy of the Galileo orbit determination is analyzed.

  14. A Space Operations Network Alternative: Using the Globally Connected Research and Education Networks for Space-based Science Operations

    Science.gov (United States)

    Bradford, Robert N.

    2006-01-01

    Earth based networking in support of various space agency projects has been based on leased service/circuits which has a high associated cost. This cost is almost always taken from the science side resulting in less science. This is a proposal to use Research and Education Networks (RENs) worldwide to support space flight operations in general and space-based science operations in particular. The RENs were developed to support scientific and educational endeavors. They do not provide support for general Internet traffic. The connectivity and performance of the research and education networks is superb. The connectivity at Layer 3 (IP) virtually encompasses the globe. Most third world countries and all developed countries have their own research and education networks, which are connected globally. Performance of the RENs especially in the developed countries is exceptional. Bandwidth capacity currently exists and future expansion promises that this capacity will continue. REN performance statistics has always exceeded minimum requirements for spaceflight support. Research and Education networks are more loosely managed than a corporate network but are highly managed when compared to the commodity Internet. Management of RENs on an international level is accomplished by the International Network Operations Center at Indiana University at Indianapolis. With few exceptions, each regional and national REN has its own network ops center. The acceptable use policies (AUP), although differing by country, allows any scientific program or project the use of their networks. Once in compliance with the first RENs AUP, all others will accept that specific traffic including regional and transoceanic networks. RENs can support spaceflight related scientific programs and projects. Getting the science to the researcher is obviously key to any scientific project. RENs provide a pathway to virtually any college or university in the world, as well as many governmental institutes and

  15. The Worldviews Network: Transformative Global Change Education in Immersive Environments

    Science.gov (United States)

    Hamilton, H.; Yu, K. C.; Gardiner, N.; McConville, D.; Connolly, R.; "Irving, Lindsay", L. S.

    2011-12-01

    Our modern age is defined by an astounding capacity to generate scientific information. From DNA to dark matter, human ingenuity and technologies create an endless stream of data about ourselves and the world of which we are a part. Yet we largely founder in transforming information into understanding, and understanding into rational action for our society as a whole. Earth and biodiversity scientists are especially frustrated by this impasse because the data they gather often point to a clash between Earth's capacity to sustain life and the decisions that humans make to garner the planet's resources. Immersive virtual environments offer an underexplored link in the translation of scientific data into public understanding, dialogue, and action. The Worldviews Network is a collaboration of scientists, artists, and educators focused on developing best practices for the use of immersive environments for science-based ecological literacy education. A central tenet of the Worldviews Network is that there are multiple ways to know and experience the world, so we are developing scientifically accurate, geographically relevant, and culturally appropriate programming to promote ecological literacy within informal science education programs across the United States. The goal of Worldviews Network is to offer transformative learning experiences, in which participants are guided on a process integrating immersive visual explorations, critical reflection and dialogue, and design-oriented approaches to action - or more simply, seeing, knowing, and doing. Our methods center on live presentations, interactive scientific visualizations, and sustainability dialogues hosted at informal science institutions. Our approach uses datasets from the life, Earth, and space sciences to illuminate the complex conditions that support life on earth and the ways in which ecological systems interact. We are leveraging scientific data from federal agencies, non-governmental organizations, and our

  16. GPP Webinar: Solar Utilization in Higher Education Networking & Information Sharing Group: Financing Issues Discussion

    Science.gov (United States)

    This presentation from a Solar Utilization in Higher Education Networking and Information webinar covers financing and project economics issues related to solar project development in the higher education sector.

  17. Massachusetts Corporation for Educational Telecommunications: Models of Collaboration for the Integration of Telecommunications in Education.

    Science.gov (United States)

    Flores, John G.

    1997-01-01

    The Massachusetts Corporation for Educational Telecommunications (MCET), a quasi-public agency, plays a leadership role in distance education and the integration of telecommunications and education locally and nationally. Operator of the Mass LearnPike satellite network and the Mass Ed OnLine LearnNet computer network, MCET provides expanded…

  18. Hierarchical graph-based segmentation for extracting road networks from high-resolution satellite images

    Science.gov (United States)

    Alshehhi, Rasha; Marpu, Prashanth Reddy

    2017-04-01

    Extraction of road networks in urban areas from remotely sensed imagery plays an important role in many urban applications (e.g. road navigation, geometric correction of urban remote sensing images, updating geographic information systems, etc.). It is normally difficult to accurately differentiate road from its background due to the complex geometry of the buildings and the acquisition geometry of the sensor. In this paper, we present a new method for extracting roads from high-resolution imagery based on hierarchical graph-based image segmentation. The proposed method consists of: 1. Extracting features (e.g., using Gabor and morphological filtering) to enhance the contrast between road and non-road pixels, 2. Graph-based segmentation consisting of (i) Constructing a graph representation of the image based on initial segmentation and (ii) Hierarchical merging and splitting of image segments based on color and shape features, and 3. Post-processing to remove irregularities in the extracted road segments. Experiments are conducted on three challenging datasets of high-resolution images to demonstrate the proposed method and compare with other similar approaches. The results demonstrate the validity and superior performance of the proposed method for road extraction in urban areas.

  19. Satellite Based Education and Training in Remote Sensing and Geo-Information AN E-Learning Approach to Meet the Growing Demands in India

    Science.gov (United States)

    Raju, P. L. N.; Gupta, P. K.

    2012-07-01

    One of the prime activities of Indian Space Research Organisation's (ISRO) Space Program is providing satellite communication services, viz., television broadcasting, mobile communication, cyclone disaster warning and rescue operations etc. so as to improve their economic conditions, disseminate technical / scientific knowledge to improve the agriculture production and education for rural people of India. ISRO, along with National Aeronautical and Space Administration (NASA) conducted experimental satellite communication project i.e. Satellite Instructional Television Experiment (SITE) using NASA's Advanced Telecommunication Satellite (i.e. ATS 6) with an objective to educate poor people of India via satellite broadcasting in 1975 and 1976, covering more than 2600 villages in six states of India and territories. Over the years India built communication satellites indigenously to meet the communication requirements of India. This has further lead to launch of an exclusive satellite from ISRO for educational purposes i.e. EDUSAT in 2004 through which rich audio-video content is transmitted / received, recreating virtual classes through interactivity. Indian Institute of Remote Sensing (IIRS) established in 1966, a premier institute in south East Asia in disseminating Remote Sensing (RS) and Geographical Information System (GIS), mainly focusing on contact based programs. But expanded the scope with satellite based Distance Learning Programs for Universities, utilizing the dedicated communication satellite i.e. EDUSAT in 2007. IIRS conducted successfully eight Distance Learning Programs in the last five years and training more than 6000 students mainly at postgraduate level from more than 60 universities /Institutions spread across India. IIRS obtained feedback and improved the programs on the continuous basis. Expanded the scope of IIRS outreach program to train user departments tailor made in any of the applications of Remote Sensing and Geoinformation, capacity

  20. Tweacher: New proposal for Online Social Networks Impact in Secondary Education

    Directory of Open Access Journals (Sweden)

    Sebastián ROMERO

    2013-05-01

    Full Text Available This paper presents and analyzes the potential uses and motivations of online social networks in education, with special emphasis on secondary education. First, we show several previous researches supporting the use of social networking as an educational tool and discuss Edmodo, an educative online social network. The work carried out during two academic years with senior students of primary and secondary schools is also analyzed. After that we present Tweacher an educative social network application and evaluate its use in the classroom to prove its useful use between teachers and students. This research has allowed us to see the reality of social network use among young people and identify the challenges of its application to education environment.

  1. Dynamic Routing Algorithm for Satellite Network Based on Ant Colony Algorithm%基于蚁群算法的卫星网动态路由算法

    Institute of Scientific and Technical Information of China (English)

    马海滨; 王汝传; 饶元

    2011-01-01

    卫星网络路由应当具有使用较小的通信开销和处理能力计算出最优路径,并能够适应卫星网络拓扑结构动态变化等特点,这与蚁群算法的特征相匹配,能很好地解决这一问题.以此为背景,提出了一种新型的基于蚁群算法的卫星网动态路由算法(DRAS-ACA),并在NS2网络仿真平台上实现了该路由算法,使用gnuplot分析了仿真结果.%Satellite network routing should have the use of smaller capacity and communication overhead to calculate the optimal path, and be able to adapt to the satellite network topology changes, and other characteristics. The Ant Colony Algorithm should be a good appraach to solve this problem. In this paper, a dynamic routing algorithm for satellite network based on ant colony algorithm (DRAS-ACA) was presented and simulated on NS2 platform,and we also analyzed the simulation results with gnuplot.

  2. Networking Algorithm in Educational Institutions in the Context of Modernisation of Russian Education

    Directory of Open Access Journals (Sweden)

    Zakharova A.V.,

    2016-12-01

    Full Text Available The paper addresses the issues of changing the structure and content of the system of higher education in response to requests coming from the state and society. As it is argued, one of the most effective management tools for universities is networking. In practice this means that educational institutions should cooperate in order to find solutions to common tasks and goals and draw on various resources (i.e. material, informational and technological, scientific etc. making them available to all participants. The paper highlights the contradiction between the future specialists’ need for innovational technologies and the impossibility to fulfill it in the rapidly changing settings of the modern society.

  3. LEO 卫星通信网络的移动性管理%Mobility management in LEO satellite communication networks

    Institute of Scientific and Technical Information of China (English)

    贺达健; 游鹏; 雍少为

    2016-01-01

    近年来,低轨道(Low Earth Orbit,LEO)卫星通信网络以全球覆盖、低传输时延、低功耗链路、较强的抗毁性等特点而受到广泛关注,是未来全球移动通信系统的重要组成部分。移动性管理是构建 LEO 卫星通信网络的关键技术,为推动移动性管理问题的研究,文章从 LEO 卫星通信网络的结构和特点入手,阐述了 LEO 卫星通信网络中移动性管理的分类,并分析了其相比地面移动无线网络的特殊性。从链路层、网络层、传输层三个协议层次综述了近年来 LEO 卫星通信网络移动性管理研究的国内外现状,重点介绍了移动 IPv6(Mobile IPv6,MIPv6)和无缝 IP 分集通用移动性结构(Seamless IP-diversity based Generalized Mobility Architecture,SIGMA)在 LEO 卫星通信网络中的应用。最后,指出了移动性管理的发展趋势。%In recent years,low Earth orbit (LEO)satellite communication networks attract a lot of researchers'attention for its global coverage,short propagation delay,low-power links and great invulnerabi lity performance,etc. It wi ll be an important part of the future global mobi le communication systems.Mobi lity management is a key technology for enabling service in LEO satellite communication networks.The characteristics, research status and problems of mobi lity management were analyzed.Fi rstly,a brief classification of mobi lity management of LEO satellite communications networks was provided and characteristics distinguished from terrestrial mobi lity wi reless networks were analyzed based on the architecture and features of LEO satellite communication networks. Then the state-of-the-art mobi lity management schemes in LEO satellite communication networks were summarized from link layer,network layer and transport layer.A detai led description of the application of MIPv6 and SIGMA in LEO satellite envi ronment was given. Finally,some trends of mobi lity management of LEO satellite communications networks

  4. Towards a Versatile Tele-Education Platform for Computer Science Educators Based on the Greek School Network

    Science.gov (United States)

    Paraskevas, Michael; Zarouchas, Thomas; Angelopoulos, Panagiotis; Perikos, Isidoros

    2013-01-01

    Now days the growing need for highly qualified computer science educators in modern educational environments is commonplace. This study examines the potential use of Greek School Network (GSN) to provide a robust and comprehensive e-training course for computer science educators in order to efficiently exploit advanced IT services and establish a…

  5. The National Centers for Ocean Sciences Education Excellence Network: Building Bridges Between Ocean Scientists and Science Education

    Science.gov (United States)

    Scowcroft, G.; Hotaling, L. A.

    2009-12-01

    Since 2002 the National Centers for Ocean Sciences Education Excellence (COSEE) Network, funded by the National Science Foundation with support from the National Oceanic and Atmospheric Administration, has worked to increase the understanding of the ocean and its relevance to society. The Network is currently comprised of twelve Centers located throughout the United States and a Central Coordinating Office. COSEE focuses on innovative activities that transform and broaden participation in the ocean science education enterprise. A key player in the national ocean literacy movement, COSEE’s objectives are to develop partnerships between ocean scientists and educators and foster communication and coordination among ocean science education programs nationwide. COSEE has grown into the nation's most comprehensive ocean science and education network with over 200 partners, including universities and research institutions, community colleges, school districts, informal science education institutions, and state/federal agencies. Each Center is a consortium of one or more ocean science research institutions, informal science education organizations, and formal education entities. The mission of the National COSEE Network is to engage scientists and educators to transform ocean sciences education. Center activities include the development of catalytic partnerships among diverse institutions, the integration of ocean science research into high-quality educational materials, and the establishment of pathways that enable ocean scientists to interact with educators, students, and the public. In addition to the work and projects implemented locally and regionally by the Centers, Network-level efforts occur across Centers, such as the national promotion of Ocean Literacy Principals and encouragement of our nation’s youth to pursue ocean related areers. This presentation will offer several examples of how the National COSEE Network is playing an important and evolving role in

  6. Developing a Mission for the National Education Network: The Challenge of Seamless Access.

    Science.gov (United States)

    Lankes, R. David; Sutton, Stuart A.

    1999-01-01

    Explores the potential mission of the National Education Network (NEN) in light of the emerging global learning infrastructure made possible by the Internet. Develops a five-part framework for exploring the nature of education information provision in a networked digital environment and examines government-sponsored and private sector initiatives.…

  7. Networks in Action: New Actors and Practices in Education Policy in Brazil

    Science.gov (United States)

    Shiroma, Eneida Oto

    2014-01-01

    This paper focuses on the role of networks in the policy-making process in education and discusses the potential of network analysis as an analytical tool for education policy research. Drawing on publically available data from personal or institutional websites, this paper reports the findings from research carried out between 2005 and 2011.…

  8. A Comparison of the Educational Research Forum and Other Computer Networks.

    Science.gov (United States)

    Pierce, Jean W.

    Designed to assist educators in selecting a computer network, this paper contains a listing and description of seven networks that currently exist specifically for educators, and compares the quality of their services in the areas of accessibility, responsiveness, cost, text editing, humanization, guidance and documentation, control, forgiveness…

  9. Massively Open Online Course for Educators (MOOC-Ed) Network Dataset

    Science.gov (United States)

    Kellogg, Shaun; Edelmann, Achim

    2015-01-01

    This paper presents the Massively Open Online Course for Educators (MOOC-Ed) network dataset. It entails information on two online communication networks resulting from two consecutive offerings of the MOOC called "The Digital Learning Transition in K-12 Schools" in spring and fall 2013. The courses were offered to educators from the USA…

  10. Mapping the Field of Educational Administration Research: A Journal Citation Network Analysis

    Science.gov (United States)

    Wang, Yinying; Bowers, Alex J.

    2016-01-01

    Purpose: The purpose of this paper is to uncover how knowledge is exchanged and disseminated in the educational administration research literature through the journal citation network. Design/ Methodology/Approach: Drawing upon social network theory and citation network studies in other disciplines, the authors constructed an educational…

  11. ASPEN, the Alberta Special Education Network: Using Appropriate Technology to Bring the Community Together.

    Science.gov (United States)

    Hill, W. Leigh; Anthony, Matthew

    1991-01-01

    The Alberta Special Education Network (ASPEN) is a computer-based communications and information network geared to the teaching and learning of exceptional children in rural Alberta, Canada. Network features include toll-free telephone access, a menu-driven user interface, training and awareness, electronic mail, weekly news, forums, and a…

  12. The Canadian Geoscience Education Network: a collaborative grassroots effort to support geoscience education

    Science.gov (United States)

    Bank, C.; Halfkenny, B.; Hymers, L.; Clinton, L.; Heenan, S.; Jackson, D.; Nowlan, G.; Haidl, F.; Vodden, C.

    2009-12-01

    The Canadian Geoscience Education Network (CGEN) numbers over 300 members who are active in promoting geoscience to the general public and especially in schools. Our membership spreads from coast to coast to coast in Canada and represents the wide range of geosciences. Most members work in education, government, industry, academia, or not-for-profit organizations. Our common goals are to (1) provide resources to teachers for the K-12 curriculum, (2) encourage students to pursue higher education and a rewarding career in geoscience, and (3) lobby to effect change to the school curriculum. Our strength is grounded in a grassroots approach (eg, regional chapters), flexible organization, and emphasis on a cost-effective style. Together we have created and maintain resources for teachers; for example, EdGEO (local workshops for teachers), Geoscape (community-based posters and lesson plans), and EarthNet (virtual resource centre). A new website showcases careers in the Earth sciences. CGEN members ensure that these resources remain current, promote them at individual outreach activities, and see to it that they are maintained. Although we have limited funding we draw strength from the networks of our members and capitalize on partnerships between seemingly disparate organizations and groups to get experts involved in the education of future geoscientists. (Details about CGEN may be found at http://www.geoscience.ca/cgen/principal.html.)

  13. Web based educational tool for neural network robot control

    Directory of Open Access Journals (Sweden)

    Jure Čas

    2007-05-01

    Full Text Available Abstract— This paper describes the application for teleoperations of the SCARA robot via the internet. The SCARA robot is used by students of mehatronics at the University of Maribor as a remote educational tool. The developed software consists of two parts i.e. the continuous neural network sliding mode controller (CNNSMC and the graphical user interface (GUI. Application is based on two well-known commercially available software packages i.e. MATLAB/Simulink and LabVIEW. Matlab/Simulink and the DSP2 Library for Simulink are used for control algorithm development, simulation and executable code generation. While this code is executing on the DSP-2 Roby controller and through the analog and digital I/O lines drives the real process, LabVIEW virtual instrument (VI, running on the PC, is used as a user front end. LabVIEW VI provides the ability for on-line parameter tuning, signal monitoring, on-line analysis and via Remote Panels technology also teleoperation. The main advantage of a CNNSMC is the exploitation of its self-learning capability. When friction or an unexpected impediment occurs for example, the user of a remote application has no information about any changed robot dynamic and thus is unable to dispatch it manually. This is not a control problem anymore because, when a CNNSMC is used, any approximation of changed robot dynamic is estimated independently of the remote’s user. Index Terms—LabVIEW; Matlab/Simulink; Neural network control; remote educational tool; robotics

  14. LEO/MEO双层卫星网络设计及仿真%Design and Simulation on a LEO/MEO Double-Layered Satellite Network

    Institute of Scientific and Technical Information of China (English)

    张基伟; 梁俊; 肖楠; 田斌

    2011-01-01

    Aiming at the issue of simplex function and low reliability in monolayer satellite network and high ISL complexity in three-layered satellite network, a framework of LEO/MEO network is proposed. Based on the "worst observational point" and " street of coverage" theory, a discontinuous connection LFO/MEO constellation is designed, and the principle to establish ISL is put forward. Furthermore , experimental results show that the network has the ability of global coverage and is easy to establish ISL.%针对单层卫星网络功能单一、可靠性较低以及三重卫星网络链路冗余度过高、实现复杂的问题,提出了利用LEO/MEO卫星构建双层网络的构想.基于"最坏观察点"与"覆盖带"理论设计了"弱连接"的LEO/MEO双层卫星网络星座,给出了星际链路建立原则.仿真结果表明,所设计的卫星网络具有全天时全球覆盖能力,有利于星际链路的建立.

  15. Investigation into the use of satellite remote sensing data products as part of a multi-modal marine environmental monitoring network

    Science.gov (United States)

    O'Connor, Edel; Smeaton, Alan F.; O'Connor, Noel E.; Regan, Fiona

    2012-09-01

    In this paper it is investigated how conventional in-situ sensor networks can be complemented by the satellite data streams available through numerous platforms orbiting the earth and the combined analyses products available through services such as MyOcean. Despite the numerous benefits associated with the use of satellite remote sensing data products, there are a number of limitations with their use in coastal zones. Here the ability of these data sources to provide contextual awareness, redundancy and increased efficiency to an in-situ sensor network is investigated. The potential use of a variety of chlorophyll and SST data products as additional data sources in the SmartBay monitoring network in Galway Bay, Ireland is analysed. The ultimate goal is to investigate the ability of these products to create a smarter marine monitoring network with increased efficiency. Overall it was found that while care needs to be taken in choosing these products, there was extremely promising performance from a number of these products that would be suitable in the context of a number of applications especially in relation to SST. It was more difficult to come to conclusive results for the chlorophyll analysis.

  16. Model of a neural network inertial satellite navigation system capable of estimating the earth's gravitational field gradient

    Science.gov (United States)

    Devyatisil'nyi, A. S.

    2016-09-01

    A model for recognizing inertial and satellite data on an object's motion that are delivered by a set of distributed onboard sensors (newtonmeters, gyros, satellite receivers) has been described. Specifically, the model is capable of estimating the parameters of the gravitational field.

  17. Satellite outreach in Asia and the Pacific.

    Science.gov (United States)

    1977-01-01

    Communication by satellite is rapidly changing information exchange in Asia, especially for rural areas. The integrated education planned for satellite networks includes family planning as part of general development. A series of conferences has already been held successfully via satellite for family planning associations who are members of the East and Southeast Asia and Oceania Region of the International Planned Parenthood Federation. These included a conference on nursing training. In India the Satellite Instructional Television Experiment (SITE) made history during its 1-year trial. By 1981 the entire nation is to be linked by satellite. The question is whether the television education will truly change rural life or whether it will become merely a diversion. In Indonesia, satellites were chosen as the fastest way to obtain interisland communication. The Domsat system links the entire 13,000-island archipelago and is already being used for emergency communications. The system, which was developed in 1 1/2 years by the Hughes Aircraft Corporation will be used for teaching basic health, hygiene, and family planning. It will be several years before Domsat is fully operational, but it bears watching.

  18. Status of the fast mission: Micro-satellite formation flying for technology, science and education

    NARCIS (Netherlands)

    Guo, J.; Maessen, D.C.; Gill, E.K.A.; Moon, S.G.; Zheng, G.

    2009-01-01

    FAST (Formation for Atmospheric Science and Technology demonstration) is a cooperative Dutch Chinese formation flying mission led by Delft University of Technology (TU Delft) in the Netherlands and Tsinghua University in China. It is expected to be the first international micro-satellite formation f

  19. Status of the fast mission: Micro-satellite formation flying for technology, science and education

    NARCIS (Netherlands)

    Guo, J.; Maessen, D.C.; Gill, E.K.A.; Moon, S.G.; Zheng, G.

    2009-01-01

    FAST (Formation for Atmospheric Science and Technology demonstration) is a cooperative Dutch Chinese formation flying mission led by Delft University of Technology (TU Delft) in the Netherlands and Tsinghua University in China. It is expected to be the first international micro-satellite formation

  20. Status of the fast mission: Micro-satellite formation flying for technology, science and education

    NARCIS (Netherlands)

    Guo, J.; Maessen, D.C.; Gill, E.K.A.; Moon, S.G.; Zheng, G.

    2009-01-01

    FAST (Formation for Atmospheric Science and Technology demonstration) is a cooperative Dutch Chinese formation flying mission led by Delft University of Technology (TU Delft) in the Netherlands and Tsinghua University in China. It is expected to be the first international micro-satellite formation f

  1. Demonstration system design of double-layered optical satellite network%双层卫星光网络仿真演示系统设计

    Institute of Scientific and Technical Information of China (English)

    李勇军; 赵尚弘; 吴继礼; 朱子行; 王翔; 赵顾灏; 姜晓峰

    2011-01-01

    In order to simulate and demonstrate the maintaining and handover of inter-orbit links of double-layered optical satellite network accurately, a hardware-in-the-loop demonstration system of asynchronous handover optical satellite network was designed in the scale of 1:30. The system was composed of demonstration hardware platform and computer simulation platform which were connected by System-In-the-Loop (SITL) module. Hardware platform was made up of a circular rotor mounted two servo-optical communication terminals and four servo-optical communication terminals which were located on the two sides of the circular rotor. The former demonstrated the LEO satellites and the latter demonstrated the MEO satellites. The system period was 280 s, the rotational velocity of circular rotor was 1.28(°)/s and the handover time from LEO satellites to MEO satellites was 4 s. The software environment was composed of computer virtual networks, in which flexible on board routing and processing may be performed. The demonstration system can achieve automatic tracking, bi-directional handover and automatic pointing. It can model OIOL (optical inter-orbit links) maintaining, data relaying and bi-directional handovers between LEO satellites andMEO satellites. Experiences from the demonstration system would be useful for the realization of LEO/MEO double-layered optical satellite network in engineering.%为了精确模拟、演示验证双层卫星光网络星际激光链路的稳定和切换,按l:30的比例设计了分时切换低/中轨道(LEO/MEO:Low Earth Orbit/Medium Earth Orbit)双层卫星光网络实验演示系统.系统由SITL(System-In-the-Loop)模块将硬件平台和计算机仿真平台互联而组成.硬件平台由中心的圆形往复转台上面的2个伺服终端和两侧的4个伺服终端组成,分别模拟LEO卫星和MEO卫星.转台平台角速度为1.28(°)/s,周期为280s,切换时间为4s.软件部分由虚拟网络组成,具有灵活的星上路由和处理

  2. Exploring social networks of municipal science education stakeholders in Danish Science Municipalities

    DEFF Research Database (Denmark)

    von der Fehr, Ane

    development in the science and technology industry. Therefore, much effort has been invested to improve science education. The importance of school external stakeholders in development of education has been an increasingly emphasised, also in the field of science education. This has led to a growing focus...... on how conditions and structures in municipalities affect the development. Projects aiming at the municipal arena have thus been initiated and the Danish Science Municipality Project (SM project) was such a project. Part of the SM project was to create networks connecting different municipal stakeholder...... involved in science education development. These municipal science education networks (MSE networks) were identified as important for development of science education in the SM project. Therefore, it was a key interest to explore these networks in order to investigate how the central stakeholders affected...

  3. SPARTAN: a global network to evaluate and enhance satellite-based estimates of ground-level particulate matter for global health applications

    Directory of Open Access Journals (Sweden)

    G. Snider

    2014-07-01

    Full Text Available Ground-based observations have insufficient spatial coverage to assess long-term human exposure to fine particulate matter (PM2.5 at the global scale. Satellite remote sensing offers a promising approach to provide information on both short- and long-term exposure to PM2.5 at local-to-global scales, but there are limitations and outstanding questions about the accuracy and precision with which ground-level aerosol mass concentrations can be inferred from satellite remote sensing alone. A key source of uncertainty is the global distribution of the relationship between annual average PM2.5 and discontinuous satellite observations of columnar aerosol optical depth (AOD. We have initiated a global network of ground-level monitoring stations designed to evaluate and enhance satellite remote sensing estimates for application in health effects research and risk assessment. This Surface PARTiculate mAtter Network (SPARTAN includes a global federation of ground-level monitors of hourly PM2.5 situated primarily in highly populated regions and collocated with existing ground-based sun photometers that measure AOD. The instruments, a three-wavelength nephelometer and impaction filter sampler for both PM2.5 and PM10, are highly autonomous. Hourly PM2.5 concentrations are inferred from the combination of weighed filters and nephelometer data. Data from existing networks were used to develop and evaluate network sampling characteristics. SPARTAN filters are analyzed for mass, black carbon, water-soluble ions, and metals. These measurements provide, in a variety of global regions, the key data required to evaluate and enhance satellite-based PM2.5 estimates used for assessing the health effects of aerosols. Mean PM2.5 concentrations across sites vary by an order of magnitude. Initial measurements indicate that the AOD column to PM2.5 ratio is driven temporally primarily by the vertical profile of aerosol scattering; and spatially by a~ more complex interaction

  4. Analysis of routing strategies in next -generation LEO satellite networks%下一代LEO卫星网络路由策略分析

    Institute of Scientific and Technical Information of China (English)

    罗雪山; 李健杰; 易先清; 唐曙

    2011-01-01

    鉴于LEO卫星网络有限的资源和高昂的建设维护成本,研究有效的LEO卫星网络路由策略成为下一代LEO卫星网络建设的关键问题.LEO卫星网络具有不同于传统的地面网络的特性,首先从对路由影响的角度对这些特性进行归纳,随后依据这些特性总结出侧重于网络拓扑结构、路由更新和负载平衡3个方面的解决方案,分析了每种方案特点,为进一步设计满足应用需求的、更为有效的下一代卫星网络路由策略奠定基础.%Studying effective routing strategies has become a critical issue in construction of LEO satellite networks because satellite network resources are very limited and maintenance costs are very great.Firstly, features of LEO satellite networks distinct from terrestrial networks are summed up according to their effects on routing issues.Subsequently, a survey of various routing strategies paying particular attention to these problems from aspects of topology, routing refreshment and load balancing is provided.By analyzing the characteristic of routing schemes in their various aspects, a foundation of designing more effective routing strategies to meet the needs of future applications is laid.

  5. Energy-Efficient Source Authentication for Secure Group Communication with Low-Powered Smart Devices in Hybrid Wireless/Satellite Networks

    Directory of Open Access Journals (Sweden)

    Baras JohnS

    2011-01-01

    Full Text Available We describe a new class of lightweight, symmetric-key digital certificates called extended TESLA certificates and a source authentication protocol for wireless group communication that is based on the certificate. The certificate binds the identity of a wireless smart device to the anchor element of its key chain; keys from the chain are used for computing message authentication codes (MACs on messages sourced by the device. The authentication protocol requires a centralized infrastructure in the network: we describe the protocol in a hybrid wireless network with a satellite overlay interconnecting the wireless devices. The satellite is used as the Certificate Authority (CA and also acts as the proxy for the senders in disclosing the MAC keys to the receivers. We also design a probabilistic nonrepudiation mechanism that utilizes the satellite's role as the CA and sender proxy. Through analysis, we show that the authentication protocol is secure against malicious adversaries. We also present detailed simulation results that demonstrate that the proposed protocol is much cheaper than traditional public key-based authentication technologies for metrics like processing delay, storage requirements, and energy consumption of the smart devices.

  6. Enviromental Education and Networking in Mafeteng Primary Schools: A Participatory Approach

    OpenAIRE

    BITSO, Constance

    2006-01-01

    This paper explores a participatory process of Environmental Education (EE) networking in Mafeteng primary schools. It gives an overview of the existing EE efforts in Lesotho, particularly the models schools of the National Curriculum Development Centre. It also provides information about Lesotho Environmental Information Network as the body that drove the networking process. The paper discusses cycles of the participatory process undertaken for the EE networking in Mafeteng schools, includi...

  7. Innovation, Quality and Networking in Engineering Education in Europe: the Contribution of SOCRATES THEMATIC NETWORKS

    Science.gov (United States)

    Borri, Claudio; Guberti, Elisa; Maffioli, Francesco

    Accreditation of the degree programmes in Engineering is surely an argument which stimulates a great interest not only in the Italian level but above all in the European perspective. It appears strategic that Europe is equipped with a system which permits to compare the degree programmes in Engineering offered by various universities in Europe also in view of a major competition in the area of higher education in the European Union, in comparison with third countries. This appears the principal basis of different actions financed by the European Commission, which have among their own objectives also the study of an accreditation system of the degree programmes in Engineering in Europe. In this article 3 SOCRATES Thematic Networks are presented, which, one after the other, starting from 1998, have been operational in the European panorama. Among their objectives there is a recurrent motive: accreditation of the degree programmes in Engineering in Europe.

  8. Personal communication networks and the effects of an entertainment-education radio soap opera in Tanzania.

    Science.gov (United States)

    Mohammed, S

    2001-01-01

    The personal networks of listeners and nonlisteners to an entertainment-education radio soap opera in Tanzania are examined to determine the effects of interpersonal discussion of the soap opera's educational themes of family planning and HIV prevention. Listeners are more likely to discuss these two educational issues in their personal communication networks and are also more likely to have other listeners to the radio program in their personal communication networks. Respondents demonstrate a relatively high degree of homophily with their network partners and are more likely to discuss matters arising from the radio program with their network partners who are of similar tribal membership, religious affiliation, and gender, and those who are equally or more highly educated than themselves.

  9. KEY ISSUES OF CONCEPTS' FORMATION OF THE NETWORK OF RESOURCE CENTER OF DISTANCE EDUCATION OF GENERAL EDUCATION INSTITUTIONS

    Directory of Open Access Journals (Sweden)

    Yuriy M. Bogachkov

    2013-06-01

    Full Text Available In the article the problem of constructing a network of resource centers for Distance Education to meet the needs of general secondary schools is presented. Modern educational trends in the use of Internet services in education are viewed.  Main contradictions, solution of which helps to create a network of resource centers, are identified. The definition of key terms related to the range of issues are given. The basic categories of participants, who  implementation of e-learning and networking are oriented on. There are considered the basic tasks of  distance education resource centers' functioning and types of supporting: personnel, regulatory, informative, systematic and  technical etc. The review of possible models of implementation of  students' distance education is reviewed . Three options for business models of resource centers, depending on funding  sources are offered.

  10. Networking and Special Educational Institutions for the Purpose of Socialization of Children with Disabilities

    Science.gov (United States)

    Valiullina, Gulnara V.; Fedotova, Anastasia E.

    2016-01-01

    The relevance to the article topic due to the fact that the network character of interaction of educational institutions aims at the implementation of accessible education of children with disabilities as a strategic objective of educational policy of Russian Federation. The purpose of the article is to analyze the existing models of network…

  11. Focus on Technology's Impact on Postsecondary Education. Network News. Volume 23, Number 1

    Science.gov (United States)

    L'Orange, Hans P., Ed.

    2004-01-01

    "Network News" provides an overview of technology's impact on postsecondary education. Particular attention is paid to recent studies looking at distance education and access. This issue contains the following articles: (1) New NCES Report: Distance Education at Degree-Granting Postsecondary Institutions 2000-2001; (2) How Does Technology Affect…

  12. Project on Application of Modern Communication Technologies to Educational Networking. Final Technical Report.

    Science.gov (United States)

    Morgan, Robert P.; Eastwood, Lester F., Jr.

    Research on this National Science Foundation grant to study the application of modern communications technology to educational networking was divided into three parts: assessment of the role of technology in non-traditional post-secondary education; assessment of communications technologies and educational services of current or potential future…

  13. ("un")Doing the Next Generation Science Standards: Climate Change Education Actor-Networks in Oklahoma

    Science.gov (United States)

    Colston, Nicole M.; Ivey, Toni A.

    2015-01-01

    This exploratory research investigated how science education communities of practice in Oklahoma engage in translations of climate change education (CCE). Applications of actor-network theory to educational policymaking facilitate this analysis of the spaces of prescription and spaces of negotiation that characterize CCE in Oklahoma. Informed by…

  14. A New Traffic Flow Prediction Algorithm for Satellite Communication Network%一种新的卫星通信网流量预测算法*

    Institute of Scientific and Technical Information of China (English)

    秦红祥; 杨飞

    2013-01-01

      在通信网络的设计中,使用基于流量预测的网络规划已成为LTE发展的必然趋势。与地面网络不同,卫星网络由于受资源受限和拓扑时变的不利影响,其流量预测算法必须能兼顾精度和效率,这令传统的地面网络预测方法已不再适用。为了解决以上问题,提出了一种新的基于小波回声状态网络的流量预测算法,该算法通过小波多尺度分解的信号处理方法屏蔽了网络流量的噪声,而后结合了无反馈的回声状态网络联合进行预测。仿真证明,新算法相比传统算法能大幅提升网络流量的预测精度和运行效率,为卫星网络的流量规划提供了强有力的决策支持。%In the design of a communication network,it has become an inevitable trend with LET development to use traffic flow prediction method for network planning. Due to suffer from the constrained resource and change-able topology,the traffic flow prediction algorithm of the satellite networks which is different from terrestrial net-works,should fully take into account the accuracy and efficiency,so the traditional prediction methods for ter-restrial networks are no longer fit for application. In order to resolve this problem,a new traffic flow prediction algorithm based on wavelet and echo state networks is proposed in this paper. The new algorithm uses the signal processing method based on multi-scale decomposition of wavelet to shield the noise of the network traffic,and it combines with the non-feedback echo state network to predict. The simulation results show that the new algorithm can greatly improve the prediction accuracy and running efficiency of network traffic compared with traditional al-gorithms,so it provides a more scientific decision support for satellite communication network traffic planning.

  15. [Benefit of network education to college students' knowledge about sexual and reproductive health in Ningbo city].

    Science.gov (United States)

    Wang, Guo-yao; Ji, Yun-xin; Ding, Hui-qing; Gui, Zhong-bao; Liang, Xiao-ming; Fu, Jian-fei; Cheng, Yue

    2015-12-01

    To investigate how network education can improve college students' knowledge on sexual and reproductive health in Ningbo city. From December 2012 to June 2013, we conducted a questionnaire investigation among college students in Ningbo city about the effects of network education on their knowledge about sexual psychology, sexual physiology, sexual ethics, and reproductive health. A total of 7 362 college students accomplished the investigation, of whom 2 483 (42.1% males and 57.9% females) received network education, while the other 4 879 (24.1% males and 75.9% females) did not. Approximately 47.1% of the male and 28.0% of the female students acquired sexual and reproductive knowledge via network education. Reproductive health-related network education significantly enriched the students' knowledge about the reproductive system and sex, pubertal development, sexual physiology, conception and embryonic development, methods of contraception, sexual psychology, sexually transmitted diseases and their prevention, pregnancy care and eugenics, and environment- and occupation-related reproductive health (P reproductive health knowledge (P reproductive health-related network education showed a significantly higher rate of masturbation (P education can enhance the effect of reproductive health education among college students and improve their sexual experience and health.

  16. Exploring social networks of municipal science education stakeholders in Danish Science Municipalities

    DEFF Research Database (Denmark)

    von der Fehr, Ane

    development of science education. By use of social network analysis (SNA), four MSE networks were approached empirically, and the municipal stakeholders and the relationships connecting them were mapped. The central stakeholders were identified based on quantitative network data. Through qualitative......Science education development is a field of many interests and a key interest is recruitment of students who wish to pursue an education in science. This is an urgent societal demand in Denmark as well as internationally, since highly skilled science graduates are needed for the continuous...

  17. Networks of Learning : Professional Association and the Continuing Education of Teachers of Mathematics in Pakistan

    DEFF Research Database (Denmark)

    Baber, Sikunder Ali

    . The formation and growth of this network can be viewed as developing insights into the improvement of mathematics education in the developing world. The contributions of the association may also add value to the learning of teacher colleagues in other parts of the world. This sharing of the experience may...... and policy makers have been recently receiving attention an innovative and flexible professional development forum for creating ownership among these stakeholders' regarding implementing change and reforms in educational landscape in different countries. The paper draws on the notion of "networking...... further support in opening up possibilities for creating other networks of learning to assist reform efforts in education throughout the world....

  18. Theory of geostationary satellites

    CERN Document Server

    Zee, Chong-Hung

    1989-01-01

    Geostationary or equatorial synchronous satellites are a daily reminder of our space efforts during the past two decades. The nightly television satellite weather picture, the intercontinental telecommunications of television transmissions and telephone conversations, and the establishrnent of educational programs in remote regions on Earth are constant reminders of the presence of these satellites. As used here, the term 'geo­ stationary' must be taken loosely because, in the long run, the satellites will not remain 'stationary' with respect to an Earth-fixed reference frame. This results from the fact that these satellites, as is true for all satellites, are incessantly subject to perturbations other than the central-body attraction of the Earth. Among the more predominant pertur­ bations are: the ellipticity of the Earth's equator, the Sun and Moon, and solar radiation pressure. Higher harmonics of the Earth's potential and tidal effects also influence satellite motion, but they are of second­ order whe...

  19. Wave activity (planetary, tidal) throughout the middle atmosphere (20-100km) over the CUJO network: Satellite (TOMS) and Medium Frequency (MF) radar observations

    OpenAIRE

    Manson, A. H.; Meek, C. E.; Chshyolkova, T.; Avery, S. K.; Thorsen, D.; MacDougall, J.W.; Hocking, W.; Murayama, Y.; Igarashi, K

    2005-01-01

    Planetary and tidal wave activity in the tropopause-lower stratosphere and mesosphere-lower thermosphere (MLT) is studied using combinations of ground-based (GB) and satellite instruments (2000-2002). The relatively new MFR (medium frequency radar) at Platteville (40° N, 105° W) has provided the opportunity to create an operational network of middle-latitude MFRs, stretching from 81° W-142° E, which provides winds and tides 70-100km. CUJO (Canada U.S. Japan Opp...

  20. A Successful Approach to Improving High School Mathematics Education: COME ON (California's Outstanding Math Educators' Ongoing Network)

    Science.gov (United States)

    St. John, Mark; Heenan, Barbara; Tambe, Pamela

    2009-01-01

    The California's Outstanding Math Educators' Ongoing Network (COME ON) initiative is a unique and innovative effort to support high school mathematics teachers in California. It serves as a living example of a successful model that addresses an issue critical to all of mathematics education K-18--how to sustain and strengthen those most directly…

  1. 34 CFR 412.1 - What is the National Network for Curriculum Coordination in Vocational and Technical Education?

    Science.gov (United States)

    2010-07-01

    ... Coordination in Vocational and Technical Education? 412.1 Section 412.1 Education Regulations of the Offices of... EDUCATION NATIONAL NETWORK FOR CURRICULUM COORDINATION IN VOCATIONAL AND TECHNICAL EDUCATION General § 412.1 What is the National Network for Curriculum Coordination in Vocational and Technical......

  2. Surgical education via the Internet: the Cardiothoracic Surgery Network.

    Science.gov (United States)

    Doty, J R; Liddicoat, J R; Salomon, N W; Greene, P S

    1998-11-01

    The Cardiothoracic Surgery Network is an international collaborative effort among cardiothoracic surgeons that provides a common platform for the exchange of information. The Cardiothoracic Surgery Network website provides peer-reviewed journals, multimedia applications, and a database repository.

  3. Entrepreneurs’ gender, age and education affecting their networks in private and public spheres: Denmark, Middle East and North Africa

    DEFF Research Database (Denmark)

    Ashourizadeh, Shayegheh; Schøtt, Thomas

    2013-01-01

    of the Middle East and North Africa. Analyses show that entrepreneurs are networking in the private sphere of family and friends, especially in traditional culture in Middle East and North Africa, and are networking in public spheres, especially in secular-rational culture in Denmark. Male entrepreneurs network...... broader than female entrepreneurs, especially in the public sphere and especially in traditional culture, whereas women network more intensely in the private sphere. Age influences networking in the way that networking in the private sphere is more extensive among young than among older entrepreneurs....... Education influences networking in the way that networking in the public sphere is especially extensive among educated entrepreneurs....

  4. Masculinity, Educational Achievement and Social Status: A Social Network Analysis

    Science.gov (United States)

    Lusher, Dean

    2011-01-01

    This study utilises a quantitative case study social network approach to explore the connection between masculinity and scholastic achievement in two secondary, all-boys schools in Australia. In both schools two social networks representing social status are explored: the "friendship" network as a measure of status that includes…

  5. THE PREPARATION OF A SPECIALIST IN NETWORKING CULTURAL-EDUCATIONAL SPACE OF UNIVERSITY

    Directory of Open Access Journals (Sweden)

    Zinaida Kekeeva

    2015-12-01

    Full Text Available The article deals with specialist preparation problems in networking cultural-educational space of the University. The authors consider the role of networking technologies in quality improvement of educational services in the conditions of the international cooperation. They also substantiate the process of entering the future experts in the working environment, the formation of their professional and personal competencies. The article reveals priority areas of training new generation specialists in the cultural and educational space of the university taking into account modern educational trends in the world.

  6. Integrated Satellite-HAP Systems

    DEFF Research Database (Denmark)

    Cianca, Ernestina; De Sanctis, Mauro; De Luise, Aldo

    2005-01-01

    for an efficient hybrid terrestrial-satellite communication system. Two integrated HAP-satellite scenarios are presented, in which the HAP is used to overcome some of the shortcomings of satellite- based communications. Moreover, it is shown that the integration of HAPs with satellite systems can be used......Thus far, high-altitude platform (HAP)-based systems have been mainly conceived as an alternative to satellites for complementing the terrestrial network. This article aims to show that HAP should no longer be seen as a competitor technology by investors of satellites, but as a key element...

  7. Improved monitoring of phytoplankton bloom dynamics in a Norwegian fjord by integrating satellite data, pigment analysis, and Ferrybox data with a coastal observation network

    Science.gov (United States)

    Volent, Zsolt; Johnsen, Geir; Hovland, Erlend K.; Folkestad, Are; Olsen, Lasse M.; Tangen, Karl; Sørensen, Kai

    2011-01-01

    Monitoring of the coastal environment is vitally important as these areas are of economic value and at the same time highly exposed to anthropogenic influence, in addition to variation of environmental variables. In this paper we show how the combination of bio-optical data from satellites, analysis of water samples, and a ship-mounted automatic flow-through sensor system (Ferrybox) can be used to detect and monitor phytoplankton blooms both spatially and temporally. Chlorophyll a (Chl a) data and turbidity from Ferrybox are combined with remotely sensed Chl a and total suspended matter from the MERIS instrument aboard the satellite ENVISAT (ENVIronmental SATellite) European Space Agency. Data from phytoplankton speciation and enumeration obtained by a national coastal observation network consisting of fish farms and the Norwegian Food Safety Authority are supplemented with data on phytoplankton pigments. All the data sets are then integrated in order to describe phytoplankton bloom dynamics in a Norwegian fjord over a growth season, with particular focus on Emiliania huxleyi. The approach represents a case example of how coastal environmental monitoring can be improved with existing instrument platforms. The objectives of the paper is to present the operative phytoplankton monitoring scheme in Norway, and to present an improved model of how such a scheme can be designed for a large part of the world's coastal areas.

  8. Planning Alternative Organizational Frameworks For a Large Scale Educational Telecommunications System Served by Fixed/Broadcast Satellites. Memorandum Number 73/3.

    Science.gov (United States)

    Walkmeyer, John

    Considerations relating to the design of organizational structures for development and control of large scale educational telecommunications systems using satellites are explored. The first part of the document deals with four issues of system-wide concern. The first is user accessibility to the system, including proximity to entry points, ability…

  9. A wavelet-based non-linear autoregressive with exogenous inputs (WNARX) dynamic neural network model for real-time flood forecasting using satellite-based rainfall products

    Science.gov (United States)

    Nanda, Trushnamayee; Sahoo, Bhabagrahi; Beria, Harsh; Chatterjee, Chandranath

    2016-08-01

    Although flood forecasting and warning system is a very important non-structural measure in flood-prone river basins, poor raingauge network as well as unavailability of rainfall data in real-time could hinder its accuracy at different lead times. Conversely, since the real-time satellite-based rainfall products are now becoming available for the data-scarce regions, their integration with the data-driven models could be effectively used for real-time flood forecasting. To address these issues in operational streamflow forecasting, a new data-driven model, namely, the wavelet-based non-linear autoregressive with exogenous inputs (WNARX) is proposed and evaluated in comparison with four other data-driven models, viz., the linear autoregressive moving average with exogenous inputs (ARMAX), static artificial neural network (ANN), wavelet-based ANN (WANN), and dynamic nonlinear autoregressive with exogenous inputs (NARX) models. First, the quality of input rainfall products of Tropical Rainfall Measuring Mission Multi-satellite Precipitation Analysis (TMPA), viz., TRMM and TRMM-real-time (RT) rainfall products is assessed through statistical evaluation. The results reveal that the satellite rainfall products moderately correlate with the observed rainfall, with the gauge-adjusted TRMM product outperforming the real-time TRMM-RT product. The TRMM rainfall product better captures the ground observations up to 95 percentile range (30.11 mm/day), although the hit rate decreases for high rainfall intensity. The effect of antecedent rainfall (AR) and climate forecast system reanalysis (CFSR) temperature product on the catchment response is tested in all the developed models. The results reveal that, during real-time flow simulation, the satellite-based rainfall products generally perform worse than the gauge-based rainfall. Moreover, as compared to the existing models, the flow forecasting by the WNARX model is way better than the other four models studied herein with the

  10. Use of the Advanced Communications Technology Satellite to Promote International Distance Education Programs for Georgetown University

    Science.gov (United States)

    Bradley, Harold; Kauffman, Amy

    1996-01-01

    Georgetown's distance education program is designed to demonstrate to faculty and administrators the feasibility and desirability of using two-way video transmission for international education. These programs will extend the reach of Georgetown's educational offerings; enrich the curriculum and content of Georgetown's offerings by interaction with institutions in other nations; enhance the world view of the School of Business Administration; enable Georgetown to share its resources with other institutions outside of the United States; and promote Commerce within the Americas. The primary reason for this pilot program is to evaluate the effectiveness and economic viability of offering academic courses and Small Business Development training.

  11. Satellite Communication.

    Science.gov (United States)

    Technology Teacher, 1985

    1985-01-01

    Presents a discussion of communication satellites: explains the principles of satellite communication, describes examples of how governments and industries are currently applying communication satellites, analyzes issues confronting satellite communication, links mathematics and science to the study of satellite communication, and applies…

  12. Validation of networks derived from snowball sampling of municipal science education actors

    DEFF Research Database (Denmark)

    von der Fehr, Ane; Sølberg, Jan; Bruun, Jesper

    2016-01-01

    Social network analysis (SNA) has been used in many educational studies in the past decade, but what these studies have in common is that the populations in question in most cases are defined and known to the researchers studying the networks. Snowball sampling is an SNA methodology most often us...

  13. A Report on Facilitating Educational Change with Local School Districts through the National Diffusion Network.

    Science.gov (United States)

    Parish, Ralph

    The National Diffusion Network was initiated in 1974 by the United States Office of Education (USOE). Thirty states developed state facilitators the first year and 36 states had facilitators the second year. Among the facilitators in the network, there appears to be considerable difference in the approaches that are taken to diffuse the projects…

  14. Lines of Sight in the "Network Society": Simulation, Art Education, and a Digital Visual Culture

    Science.gov (United States)

    Sweeny, Robert W.

    2004-01-01

    Contemporary societies are in the process of developing digital technological networks that simultaneously result in their transformation. The operations of networked computer systems, based in forms of simulation, have shifted general notions of visuality within a visual culture. Practices in art education that address these contemporary…

  15. Network-Based Leadership Development: A Guiding Framework and Resources for Management Educators

    Science.gov (United States)

    Cullen-Lester, Kristin L.; Woehler, Meredith L.; Willburn, Phil

    2016-01-01

    Management education and leadership development has traditionally focused on improving human capital (i.e., knowledge, skills, and abilities). Social capital, networks, and networking skills have received less attention. When this content has been incorporated into learning and development experiences, it has often been more ad hoc and has…

  16. WiFiSiM: An Educational Tool for the Study and Design of Wireless Networks

    Science.gov (United States)

    Mateo Sanguino, T. J.; Serrano Lopez, C.; Marquez Hernandez, F. A.

    2013-01-01

    A new educational simulation tool designed for the generic study of wireless networks, the Wireless Fidelity Simulator (WiFiSim), is presented in this paper. The goal of this work was to create and implement a didactic tool to improve the teaching and learning of computer networks by means of two complementary strategies: simulating the behavior…

  17. PCs for Families: A Study of Early Intervention Using Networked Computing in Education.

    Science.gov (United States)

    Reaux, Ray A.; Ehrich, Roger W.; McCreary, Faith; Rowland, Keith; Hood, Susan

    1998-01-01

    Discusses the PCs for Families experiment, a longitudinal quantitative and ethnographic study of networked computing in the fifth-grade classroom examining how networked computing affects students' educational achievements, attitude and professional development of teachers and support instructors, and how families support students and react to the…

  18. ESA's satellite communications programme

    Science.gov (United States)

    Bartholome, P.

    1985-02-01

    The developmental history, current status, and future plans of the ESA satellite-communications programs are discussed in a general survey and illustrated with network diagrams and maps. Consideration is given to the parallel development of national and European direct-broadcast systems and telecommunications networks, the position of the European space and electronics industries in the growing world market, the impact of technological improvements (both in satellite systems and in ground-based networks), and the technological and commercial advantages of integrated space-terrestrial networks. The needs for a European definition of the precise national and international roles of satellite communications, for maximum speed in implementing such decisions (before the technology becomes obsolete), and for increased cooperation and standardization to assure European equipment manufacturers a reasonable share of the market are stressed.

  19. Adoption of Social Networking in Education: A Study of the Use of Social Networks by Higher Education Students in Oman

    Science.gov (United States)

    Al-Mukhaini, Elham M.; Al-Qayoudhi, Wafa S.; Al-Badi, Ali H.

    2014-01-01

    The use of social networks is a growing phenomenon, being increasingly important in both private and academic life. Social networks are used as tools to enable users to have social interaction. The use of social networks (SNs) complements and enhances the teaching in traditional classrooms. For example, YouTube, Facebook, wikis, and blogs provide…

  20. Adoption of Social Networking in Education: A Study of the Use of Social Networks by Higher Education Students in Oman

    Science.gov (United States)

    Al-Mukhaini, Elham M.; Al-Qayoudhi, Wafa S.; Al-Badi, Ali H.

    2014-01-01

    The use of social networks is a growing phenomenon, being increasingly important in both private and academic life. Social networks are used as tools to enable users to have social interaction. The use of social networks (SNs) complements and enhances the teaching in traditional classrooms. For example, YouTube, Facebook, wikis, and blogs provide…

  1. The Utrecht Pharmacy Practice network for Education and Research: a network of community and hospital pharmacies in the Netherlands.

    Science.gov (United States)

    Koster, Ellen S; Blom, Lyda; Philbert, Daphne; Rump, Willem; Bouvy, Marcel L

    2014-08-01

    Practice-based networks can serve as effective mechanisms for the development of the profession of pharmacists, on the one hand by supporting student internships and on the other hand by collection of research data and implementation of research outcomes among public health practice settings. This paper presents the characteristics and benefits of the Utrecht Pharmacy Practice network for Education and Research, a practice based research network affiliated with the Department of Pharmaceutical Sciences of Utrecht University. Yearly, this network is used to realize approximately 600 student internships (in hospital and community pharmacies) and 20 research projects. To date, most research has been performed in community pharmacy and research questions frequently concerned prescribing behavior or adherence and subjects related to uptake of regulations in the pharmacy setting. Researchers gain access to different types of data from daily practice, pharmacists receive feedback on the functioning of their own pharmacy and students get in depth insight into pharmacy practice.

  2. Feasibility Analysis on the Utilization of the Iridium Satellite Communications Network for Resident Space Objects in Low Earth Orbit

    Science.gov (United States)

    2013-03-21

    equatorial speed. Ideally, the GEO satellite remains directly overhead in the absence of perturbing forces. Of course , perturbing forces exist and cause a...respectively. Assuming a mean Earth radius of 6371 km, the Earth- central angles and can be found from trigonometry using the footprint

  3. Occupational mobility networks of female and male higher education graduates

    Directory of Open Access Journals (Sweden)

    Eliza-Olivia LUNGU

    2013-08-01

    Full Text Available We employ a network based approach to explore occupational mobility of the Romanian university graduates in the first years after graduation. This representation of data permits us to use the novel statistical techniques developed in the framework of weighted directed networks in order to extract a set of stylized facts that highlight patterns of occupational mobility: centrality, degree and network density. We find that the gender plays a significant role in shaping the patterns of occupational mobility.

  4. Satellite orbit determination and gravity field recovery from satellite-to-satellite tracking

    Science.gov (United States)

    Wakker, K. F.; Ambrosius, B. A. C.; Leenman, H.

    1989-07-01

    Studies on satellite-to-satellite tracking (SST) with POPSAT (a geodetic satellite concept) and a ERS-class (Earth observation) satellite, a Satellite-to-Satellite Tracking (SST) gravity mission, and precise gravity field determination methods and mission requirements are reported. The first two studies primarily address the application of SST between the high altitude POPSAT and an ERS-class or GRM (Geopotential Research Mission) satellite to the orbit determination of the latter two satellites. Activities focussed on the determination of the tracking coverage of the lower altitude satellite by ground based tracking systems and by POPSAT, orbit determination error analysis and the determination of the surface forces acting on GRM. The third study surveys principles of SST, uncertainties of existing drag models, effects of direct luni-solar attraction and tides on orbit and the gravity gradient observable. Detailed ARISTOTELES (which replaced POPSAT) orbit determination error analyses were performed for various ground based tracking networks.

  5. Applied Remote Sensing Education and Training (ARSET): Opportunities to shorten the learning curve in use of NASA satellite data products

    Science.gov (United States)

    Kleidman, R. G.; Prados, A. I.; Christopher, S. A.

    2010-12-01

    The previous decade has provided ample opportunity to use observations from space to constrain and enhance aerosol modeling efforts, but we find that the typical modeling professional outside of the immediate NASA environment is often overwhelmed by the breadth and depth of NASA satellite data products. NASA has invested in creating ARSET to help users learn and navigate through the maze of atmospheric products available. ARSET activities include training workshops which run from 1 to 5 days, creating educational materials and monthly air quality case study exercises in contest format. Our workshops provide what nobody else does: a clear and concise training on how to obtain and make proper use of atmospheric remote sensing products. Although our focus is on air quality applications we provide information that can be used by anyone wishing to understand and use atmospheric remote sensing products. All the materials we have used in our workshops as well as our educational materials and case studies are available at http://arset.gsfc.nasa.gov

  6. Analysis on Ideological and Moral Education in Network Era

    Institute of Scientific and Technical Information of China (English)

    ZHAN Dao-rong

    2016-01-01

    This paper analyzes the status qua of the ideological and moral education in the Institutions of Higher Learning to de-fine the key factor which the moral education. According to the educational informationazation, the paper focused on the instruc-tional design of the ideological and moral education based on the constructionism and specify problems during the process of the moral education. Through the teaching design, so that the education in the process of schooling, can have the effect of the teach-ing stage to achieve, so that the teaching effect to maximize, improve students' comprehensive quality.

  7. Exchange Studies as Actor-Networks: Following Korean Exchange Students in Swedish Higher Education

    Science.gov (United States)

    Ahn, Song-ee

    2011-01-01

    This article explores how Korean exchange students organized their studies during exchange programs in Swedish higher education. For most students, the programs became a disordered period in relation to their education. The value of exchange studies seems mainly to be extra-curricular. Drawing upon actor network theory, the article argues that the…

  8. Uncovering Influence through Social Network Analysis: The Role of Schools in Education for Sustainable Development

    Science.gov (United States)

    Kolleck, Nina

    2016-01-01

    This paper examines the implementation of Education for Sustainable Development (ESD) in Germany and explores the possibilities of Social Network Analysis (SNA) for uncovering influential actors in educational policy innovation processes. From the theoretical perspective, an actor's influence is inferred from its relative position within…

  9. The Multilingual Education (MLE) Network Phenomenon: Advocacy and Action for Minoritized Language Communities

    Science.gov (United States)

    Trudell, Barbara

    2014-01-01

    This article examines a new phenomenon in language activism variously called the multilingual education working group or the multilingual education network, and abbreviated as MLEN. After an analysis of the conceptual and organizational contexts for these activist groups, the six MLENs in existence as of 2013 are described. The groups are then…

  10. Parental Networks, Ethnicity, and Social and Cultural Capital: The Societal Dynamics of Educational Resilience in Turkey

    Science.gov (United States)

    Çelik, Çetin

    2017-01-01

    Resilience research has increasingly gained ground in the field of education research, due to its potential for ameliorating inequalities. This article deals with the emergence of educational resilience, with particular attention to parental network structure, by employing a Bourdieusian social and cultural capital approach. While much of the…

  11. Exchange Studies as Actor-Networks: Following Korean Exchange Students in Swedish Higher Education

    Science.gov (United States)

    Ahn, Song-ee

    2011-01-01

    This article explores how Korean exchange students organized their studies during exchange programs in Swedish higher education. For most students, the programs became a disordered period in relation to their education. The value of exchange studies seems mainly to be extra-curricular. Drawing upon actor network theory, the article argues that the…

  12. From Radio, to Satellite, to M-Learning: Interactive Distance Education in Australia

    Science.gov (United States)

    Crump, Stephen

    2013-01-01

    This paper provides reflections on M-learning as a form of "distance education," based on a summary of the findings of the Interactive Distance e-Learning (IDL) research project in rural and remote Australia under an Australian Research Council Linkage grant. This project was a joint undertaking between 3 government agencies and an…

  13. Comparing social factors affecting recommender decisions in online and educational social network

    Science.gov (United States)

    MartÍn, Estefanía; Hernán-Losada, Isidoro; Haya, Pablo A.

    2016-01-01

    In the educational context, there is an increasing interest in learning networks. Recommender systems (RSs) can play an important role in achieving educational objectives. Although we can find many papers focused on recommendation techniques and algorithms, in general, less attention has been dedicated to social factors that influence the recommendation process. This process could be improved if we had a deeper understanding of the social factors that influence the quality or validity of a suggestion made by the RS. This work elucidates and analyses the social factors that influence the design and decision-making process of RSs. We conducted a survey in which 126 undergraduate students were asked to extract which are the main factors for improving suggestions when they are interacting with an Online Social Network (OSN) or in an Educational Social Network (ESN). The results show that different factors have to be considered depending on the type of network.

  14. 基于无速率码实现全球信息分发的双层卫星网络设计%Design of Double-layered Satellite Network to Worldwide Information Distribution Based on Rateless Codes

    Institute of Scientific and Technical Information of China (English)

    王闯; 张洪; 张威; 张更新

    2015-01-01

    This paper proposes a double-layered satellite information distribution network consisting of the GEO satel-lites and LEO satellites, which is based on the disruption tolerant characteristics of rateless codes in information distribu-tion. In the architecture of this satellite network, GEO constellation is used as the outer backbone network to provide a wide range of coverage in low latitudes, as well as to ensure the users capacity, while LEO constellation is used as the inner en-hanced network to make up the shortage of GEO backbone network's coverage. In the design of the satellite constellation net-works, considering the coverage characteristics of GEO satellites and LEO satellites, fewer satellites are adopted to achieve a worldwide information disruption tolerant distribution capacity, combined with the disruption tolerant characteristics of rateless codes. This paper simulates and analyzes the coverage capacity and the average elevation angle of the designed net-work, and the result verifies that the network can achieve a worldwide information distribution.%文章基于无速率编码在信息分发中容中断的特性,提出一种采用GEO卫星和LEO卫星组成的双层卫星信息分发网络。在该卫星网络的体系架构中,采用GEO星座作为外层骨干网络,提供中低纬度的大范围覆盖,保证用户的容量,而采用LEO星座作为内层的增强网络,弥补GEO骨干网络的覆盖不足。在卫星网络的星座设计中,考虑GEO卫星、LEO卫星的覆盖特点,结合无速率编码的容中断特性,采用较少的卫星实现信息在全球范围内的容中断分发。文章对所设计的双层卫星网络覆盖性能和平均通信仰角进行了仿真分析,验证了该网络能够实现全球范围的信息分发。

  15. Are Social Networking Websites Educational? Information Capsule. Volume 0909

    Science.gov (United States)

    Blazer, Christie

    2009-01-01

    More and more school districts across the country are joining social networking sites, such as Facebook and MySpace. This Information Capsule discusses the frequency with which school districts are using social networking sites, how districts are using the sites, and potential drawbacks associated with their use. Issues for districts to consider…

  16. Advantages of Social Network Analysis in Educational Research

    Science.gov (United States)

    Ushakov, K. M.; Kukso, K. N.

    2015-01-01

    Currently one of the main tools for the large scale studies of schools is statistical analysis. Although it is the most common method and it offers greatest opportunities for analysis, there are other quantitative methods for studying schools, such as network analysis. We discuss the potential advantages that network analysis has for educational…

  17. Globalization, Education, and the Topology of Social Networks

    OpenAIRE

    Vigier, A.

    2008-01-01

    The present paper suggests a possible framework to analyze the impact of changes to the economic and social environment on the topology of networks formed. Economic (costs) and social (norms) constraints bind individuals in their ability to create ties with others. When global phenomena affect these constraints, the overall shapes of resulting networks naturally alter. I attempt to shed light on this relationship.

  18. The Impact of Social Media and Social Networks on Education and Students of Pakistan

    Directory of Open Access Journals (Sweden)

    Waqas Tariq

    2012-07-01

    Full Text Available The impact of social websites can be good on students but if we have a closer look on the real impact of social networks. Today it is ruining the future and carrier of students. The social networking websites like https://www.linkedin.com, http://www.facebook.com/, https://twitter.com/ and https://www.orkut.com/ etc. are continuously distracting students from their studies. The main focus of student should be education but unfortunately todays student are emphasizing on such sites which can be a complete wastage of time. Social Networks was only an electronic connection between users but unfortunately it has become an addiction for students, teenagers and even adults. This paper presents impact of social networks on education, students and impact on life of teenagers, further it describes how social networking websites are auditory and dangerous for youth and teenagers.

  19. Improving Quantitative Precipitation Estimation via Data Fusion of High-Resolution Ground-based Radar Network and CMORPH Satellite-based Product

    Science.gov (United States)

    Cifelli, R.; Chen, H.; Chandrasekar, V.; Xie, P.

    2015-12-01

    A large number of precipitation products at multi-scales have been developed based upon satellite, radar, and/or rain gauge observations. However, how to produce optimal rainfall estimation for a given region is still challenging due to the spatial and temporal sampling difference of different sensors. In this study, we develop a data fusion mechanism to improve regional quantitative precipitation estimation (QPE) by utilizing satellite-based CMORPH product, ground radar measurements, as well as numerical model simulations. The CMORPH global precipitation product is essentially derived based on retrievals from passive microwave measurements and infrared observations onboard satellites (Joyce et al. 2004). The fine spatial-temporal resolution of 0.05o Lat/Lon and 30-min is appropriate for regional hydrologic and climate studies. However, it is inadequate for localized hydrometeorological applications such as urban flash flood forecasting. Via fusion of the Regional CMORPH product and local precipitation sensors, the high-resolution QPE performance can be improved. The area of interest is the Dallas-Fort Worth (DFW) Metroplex, which is the largest land-locked metropolitan area in the U.S. In addition to an NWS dual-polarization S-band WSR-88DP radar (i.e., KFWS radar), DFW hosts the high-resolution dual-polarization X-band radar network developed by the center for Collaborative Adaptive Sensing of the Atmosphere (CASA). This talk will present a general framework of precipitation data fusion based on satellite and ground observations. The detailed prototype architecture of using regional rainfall instruments to improve regional CMORPH precipitation product via multi-scale fusion techniques will also be discussed. Particularly, the temporal and spatial fusion algorithms developed for the DFW Metroplex will be described, which utilizes CMORPH product, S-band WSR-88DP, and X-band CASA radar measurements. In order to investigate the uncertainties associated with each

  20. The Construction of Higher Education Entrepreneur Services Network System a Research Based on Ecological Systems Theory

    Science.gov (United States)

    Xue, Jingxin

    The article aims to completely, systematically and objectively analyze the current situation of Entrepreneurship Education in China with Ecological Systems Theory. From this perspective, the author discusses the structure, function and its basic features of higher education entrepreneur services network system, and puts forward the opinion that every entrepreneurship organization in higher education institution does not limited to only one platform. Different functional supporting platforms should be combined closed through composite functional organization to form an integrated network system, in which each unit would impels others' development.