Science.gov

Sample records for acs events relay

  1. Real-Time Multimission Event Notification System for Mars Relay

    NASA Technical Reports Server (NTRS)

    Wallick, Michael N.; Allard, Daniel A.; Gladden, Roy E.; Wang, Paul; Hy, Franklin H.

    2013-01-01

    As the Mars Relay Network is in constant flux (missions and teams going through their daily workflow), it is imperative that users are aware of such state changes. For example, a change by an orbiter team can affect operations on a lander team. This software provides an ambient view of the real-time status of the Mars network. The Mars Relay Operations Service (MaROS) comprises a number of tools to coordinate, plan, and visualize various aspects of the Mars Relay Network. As part of MaROS, a feature set was developed that operates on several levels of the software architecture. These levels include a Web-based user interface, a back-end "ReSTlet" built in Java, and databases that store the data as it is received from the network. The result is a real-time event notification and management system, so mission teams can track and act upon events on a moment-by-moment basis. This software retrieves events from MaROS and displays them to the end user. Updates happen in real time, i.e., messages are pushed to the user while logged into the system, and queued when the user is not online for later viewing. The software does not do away with the email notifications, but augments them with in-line notifications. Further, this software expands the events that can generate a notification, and allows user-generated notifications. Existing software sends a smaller subset of mission-generated notifications via email. A common complaint of users was that the system-generated e-mails often "get lost" with other e-mail that comes in. This software allows for an expanded set (including user-generated) of notifications displayed in-line of the program. By separating notifications, this can improve a user's workflow.

  2. On the HEMP environment for protective relays. [High-altitude electromagnetic pulse

    SciTech Connect

    Thomas, D.E.; Wiggins, C.M.; Salas, T.M. ); Barnes, P.R. )

    1994-01-01

    An assessment of the transient environment for protective relays produced by high-altitude electromagnetic pulse (HEMP) events is presented in this paper. Several mechanisms for coupling of HEMP to relay terminals are used to develop estimates of possible HEMP threats to relays. These predicted relay responses to HEMP events are compared to measured data on a solid state based relay's impulse strength.

  3. New static relay for transmission line protection

    SciTech Connect

    Andrichak, J.G.; Massey, W.A.; Patterson, R.C.

    1981-01-01

    A new static ac voltage relay is described which meets the requirements of critical applications. This Static Line Voltage (SLV) relay consists of three independently adjustable detectors, each of which can be operated in the undervoltage or overvoltage mode. Each detector has a dropout to pickup ratio of 99 percent, and a high degree of immunity to harmonics (less than 3 percent variation in operating point with a voltage waveform containing 50 percent third harmonic). The outputs of the individual detectors are user programmable in the type SLV relay to provide AND, OR, or other logical combinations of output contact wiring to the external control circuits. 2 refs.

  4. On the HEMP (high-altitude electromagnetic pulse) response of protective relays

    SciTech Connect

    Thomas, D.E.; Wiggins, C.M.; Barnes, P.R.; Oak Ridge National Lab., TN )

    1990-01-01

    An assessment of the susceptibility of protective relays to the transients produced by high-altitude electromagnetic pulse (HEMP) events is presented in this paper. Several mechanisms responsible for coupling of HEMP to relay terminals are examined. The predicted relay responses to HEMP events are compared to measured data on a solid state based relay's impulse. 11 refs., 16 figs.

  5. Understanding the Design, Function and Testing of Relays

    ERIC Educational Resources Information Center

    Adams, Roger E.; Lindbloom, Trent

    2006-01-01

    The increased use of electronics in today's automobiles has complicated the control of circuits and actuators. Manufacturers use relays to control a variety of complex circuits--for example, those involving actuators and other components like the A/C clutch, electronic cooling fans, and blower motors. Relays allow a switch or processor to control…

  6. On the HEMP (high-altitude electromagnetic pulse) environment for protective relays

    SciTech Connect

    Thomas, D.E.; Wiggins, C.M.; Salas, T.M. ); Barnes, P.R. )

    1990-01-01

    An assessment of the transient environment for protective relays produced by high-altitude electromagnetic pulse (HEMP) events is presented in this paper. Several mechanisms for coupling of HEMP to relay terminals are used to develop estimates of possible HEMP threats to relays. These predicted relay responses to HEMP events are compared to measured data on a solid state based relay's impulse strength. 12 refs., 13 figs., 3 tabs.

  7. Phase protection system for ac power lines

    NASA Technical Reports Server (NTRS)

    Wong, W. J. (Inventor)

    1974-01-01

    The system described provides protection for phase sensitive loads from being or remaining connected to ac power lines whenever a phase reversal occurs. It comprises a solid state phase detection circuit, a dc power relay circuit, an ac-to-dc converter for energizing the relay circuit, and a bistable four terminal transducer coupled between the phase detection circuit and the power relay circuit, for controlling both circuits.

  8. Seismic ruggedness of relays

    SciTech Connect

    Merz, K.L. )

    1991-08-01

    This report complements EPRI report NP-5223 Revision 1, February 1991, and presents additional information and analyses concerning generic seismic ruggedness of power plant relays. Existing and new test data have been used to construct Generic Equipment Ruggedness Spectra (GERS) which can be used in identifying rugged relays during seismic re-evaluation of nuclear power plants. This document is an EPRI tier 1 report. The results of relay fragility tests for both old and new relays are included in an EPRI tier 2 report with the same title. In addition to the presentation of relay GERS, the tier 2 report addresses the applicability of GERS to relays of older vintage, discusses the important identifying nomenclature for each relay type, and examines relay adjustment effects on seismic ruggedness. 9 refs., 3 figs, 1 tab.

  9. Relay Support for the Mars Science Laboratory and the Coming Decade of Mars Relay Network Evolution

    NASA Technical Reports Server (NTRS)

    Edwards, Charles D., Jr.; Arnold, Bradford W.; Bell, David J.; Bruvold, Kristoffer N.; Gladden, Roy E.; Ilott, Peter A.; Lee, Charles H.

    2012-01-01

    Mars Relay Network is prepared to support MSL: a) ODY/MRO/MEX will all provide critical event comm support during EDL. b) New Electra/Electra-Lite capabilities on the MSL-MRO link will support >250 Mb/sol MSL data return. 2013 MAVEN orbiter will replenish on-orbit relay infrastructure as prior orbiters approach end-of-life. While NASA has withdrawn from the 2016 EMTGO and 2018 Joint Rover missions, analysis of the potential link shows a path to Gbit/sol relay capability 2012.

  10. That Article: Frame Relay.

    ERIC Educational Resources Information Center

    Schuyler, Michael

    1994-01-01

    Compares Frame Relay with digital and analog alternatives for connecting sites on a Wide Area Network. Cost considerations, the concepts on which the technology is based, its carrying capacity, the use of CD-ROM and Graphical User Interface (GUI) on Frame Relay, and engineering bandwidth limitations are covered. (KRN)

  11. MAVEN Relay Operations Concept

    NASA Technical Reports Server (NTRS)

    Chamberlain, Neil; Gladden, Roy; Bruvold, Kris

    2012-01-01

    The Mars Atmosphere and Volatile EvolutioN (MAVEN) mission will launch in late 2013 and following a 10 month cruise to Mars, will study the upper atmosphere of the planet. In addition to the science instruments, the MAVEN spacecraft is equipped with an Electra UHF transceiver to support relay communication with landed assets. This paper describes how UHF relay service is provisioned by MAVEN. The discussion includes a description of the Electra payload, the process by which relay activities are coordinated and accounted for, the process of a typical relay session, including uplink and downlink, as well as special commands to calibrate and verify relay performance. The operational processes for providing these services are inherited largely from prior Mars missions and take advantage of existing infrastructure and lessons learned from those missions. Preliminary data volume return capabilities using adaptive data rates and low-density parity check channel coding are presented.

  12. Relay Sequence Generation Software

    NASA Technical Reports Server (NTRS)

    Gladden, Roy E.; Khanampompan, Teerapat

    2009-01-01

    Due to thermal and electromagnetic interactivity between the UHF (ultrahigh frequency) radio onboard the Mars Reconnaissance Orbiter (MRO), which performs relay sessions with the Martian landers, and the remainder of the MRO payloads, it is required to integrate and de-conflict relay sessions with the MRO science plan. The MRO relay SASF/PTF (spacecraft activity sequence file/ payload target file) generation software facilitates this process by generating a PTF that is needed to integrate the periods of time during which MRO supports relay activities with the rest of the MRO science plans. The software also generates the needed command products that initiate the relay sessions, some features of which are provided by the lander team, some are managed by MRO internally, and some being derived.

  13. Multifunction protective relay

    NASA Astrophysics Data System (ADS)

    Harlow, J.; Yalla, M.; Kantor, J.

    1991-11-01

    Since the enactment of the National Energy Act of 1979, many private energy producers have been planning and building small generation and cogeneration facilities in order to sell power to the local utility. Many of the non-utility generators built after 1979 are connected directly to the closest utility distribution circuit. Aware of the problems associated with connecting generators in this manner, electric utilities across the country developed specifications and standards to allow safe and reliable interconnection. The report describes a malfunction protective relay which uses state-of-the-art digital signal processing procedures to accomplish the objective of providing most of the relay requirements of utility electrical interconnections. The relay has been demonstrated to be suitable for this critical application through extensive laboratory and in-service field testing. The relay, incorporating thirteen distinct protection functions affords the user the savings of the initial capital cost plus simplicity of installation and use.

  14. Fully relayed regenerative amplifier

    DOEpatents

    Glass, Alexander J.

    1981-01-01

    A regenerative laser apparatus and method using the optical relay concept to maintain high fill factors, to suppress diffraction effects, and to minimize phase distortions in a regenerative amplifier.

  15. A TRANSISTORIZED RELAY SERVO.

    DTIC Science & Technology

    DC motor is achieved with standard power transistors and a simple transistorized preamplifier, A permanent magnet, DC motor is used as the test vehicle to illustrate the feasibility of control without an amplidyne or mechanical relay. The ’bang-bang’, capability of the controller to operate as a near-ideal ’relay’ is emphasized. The inherent flexibility allowed in selecting the switching characteristics is also demonstrated. The discussion points toward practical application and stresses the analysis of the switching

  16. Relay Telecommunications for the Coming Decade of Mars Exploration

    NASA Technical Reports Server (NTRS)

    Edwards, C.; DePaula, R.

    2010-01-01

    Over the past decade, an evolving network of relay-equipped orbiters has advanced our capabilities for Mars exploration. NASA's Mars Global Surveyor, 2001 Mars Odyssey, and Mars Reconnaissance Orbiter (MRO), as well as ESA's Mars Express Orbiter, have provided telecommunications relay services to the 2003 Mars Exploration Rovers, Spirit and Opportunity, and to the 2007 Phoenix Lander. Based on these successes, a roadmap for continued Mars relay services is in place for the coming decade. MRO and Odyssey will provide key relay support to the 2011 Mars Science Laboratory (MSL) mission, including capture of critical event telemetry during entry, descent, and landing, as well as support for command and telemetry during surface operations, utilizing new capabilities of the Electra relay payload on MRO and the Electra-Lite payload on MSL to allow significant increase in data return relative to earlier missions. Over the remainder of the decade a number of additional orbiter and lander missions are planned, representing new orbital relay service providers and new landed relay users. In this paper we will outline this Mars relay roadmap, quantifying relay performance over time, illustrating planned support scenarios, and identifying key challenges and technology infusion opportunities.

  17. Autonomous mobile communication relays

    NASA Astrophysics Data System (ADS)

    Nguyen, Hoa G.; Everett, Hobart R.; Manouk, Narek; Verma, Ambrish

    2002-07-01

    Maintaining a solid radio communication link between a mobile robot entering a building and an external base station is a well-recognized problem. Modern digital radios, while affording high bandwidth and Internet-protocol-based automatic routing capabilities, tend to operate on line-of-sight links. The communication link degrades quickly as a robot penetrates deeper into the interior of a building. This project investigates the use of mobile autonomous communication relay nodes to extend the effective range of a mobile robot exploring a complex interior environment. Each relay node is a small mobile slave robot equipped with sonar, ladar, and 802.11b radio repeater. For demonstration purposes, four Pioneer 2-DX robots are used as autonomous mobile relays, with SSC-San Diego's ROBART III acting as the lead robot. The relay robots follow the lead robot into a building and are automatically deployed at various locations to maintain a networked communication link back to the remote operator. With their on-board external sensors, they also act as rearguards to secure areas already explored by the lead robot. As the lead robot advances and RF shortcuts are detected, relay nodes that become unnecessary will be reclaimed and reused, all transparent to the operator. This project takes advantage of recent research results from several DARPA-funded tasks at various institutions in the areas of robotic simulation, ad hoc wireless networking, route planning, and navigation. This paper describes the progress of the first six months of the project.

  18. 49 CFR 234.263 - Relays.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Relays. 234.263 Section 234.263 Transportation... Inspections and Tests § 234.263 Relays. (a) Except as stated in paragraph (b) of this section, each relay that.... (b)(1) Alternating current vane type relays, direct current polar type relays, and relays with...

  19. 49 CFR 234.263 - Relays.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Relays. 234.263 Section 234.263 Transportation... Inspections and Tests § 234.263 Relays. (a) Except as stated in paragraph (b) of this section, each relay that.... (b)(1) Alternating current vane type relays, direct current polar type relays, and relays with...

  20. High Expression of Cry1Ac Protein in Cotton (Gossypium hirsutum) by Combining Independent Transgenic Events that Target the Protein to Cytoplasm and Plastids.

    PubMed

    Singh, Amarjeet Kumar; Paritosh, Kumar; Kant, Uma; Burma, Pradeep Kumar; Pental, Deepak

    2016-01-01

    Transgenic cotton was developed using two constructs containing a truncated and codon-modified cry1Ac gene (1,848 bp), which was originally characterized from Bacillus thuringiensis subspecies kurstaki strain HD73 that encodes a toxin highly effective against many lepidopteran pests. In Construct I, the cry1Ac gene was cloned under FMVde, a strong constitutively expressing promoter, to express the encoded protein in the cytoplasm. In Construct II, the encoded protein was directed to the plastids using a transit peptide taken from the cotton rbcSIb gene. Genetic transformation experiments with Construct I resulted in a single copy insertion event in which the Cry1Ac protein expression level was 2-2.5 times greater than in the Bacillus thuringiensis cotton event Mon 531, which is currently used in varieties and hybrids grown extensively in India and elsewhere. Another high expression event was selected from transgenics developed with Construct II. The Cry protein expression resulting from this event was observed only in the green plant parts. No transgenic protein expression was observed in the non-green parts, including roots, seeds and non-green floral tissues. Thus, leucoplasts may lack the mechanism to allow entry of a protein tagged with the transit peptide from a protein that is only synthesized in tissues containing mature plastids. Combining the two events through sexual crossing led to near additive levels of the toxin at 4-5 times the level currently used in the field. The two high expression events and their combination will allow for effective resistance management against lepidopteran insect pests, particularly Helicoverpa armigera, using a high dosage strategy.

  1. High Expression of Cry1Ac Protein in Cotton (Gossypium hirsutum) by Combining Independent Transgenic Events that Target the Protein to Cytoplasm and Plastids

    PubMed Central

    Singh, Amarjeet Kumar; Paritosh, Kumar; Kant, Uma; Burma, Pradeep Kumar; Pental, Deepak

    2016-01-01

    Transgenic cotton was developed using two constructs containing a truncated and codon-modified cry1Ac gene (1,848 bp), which was originally characterized from Bacillus thuringiensis subspecies kurstaki strain HD73 that encodes a toxin highly effective against many lepidopteran pests. In Construct I, the cry1Ac gene was cloned under FMVde, a strong constitutively expressing promoter, to express the encoded protein in the cytoplasm. In Construct II, the encoded protein was directed to the plastids using a transit peptide taken from the cotton rbcSIb gene. Genetic transformation experiments with Construct I resulted in a single copy insertion event in which the Cry1Ac protein expression level was 2–2.5 times greater than in the Bacillus thuringiensis cotton event Mon 531, which is currently used in varieties and hybrids grown extensively in India and elsewhere. Another high expression event was selected from transgenics developed with Construct II. The Cry protein expression resulting from this event was observed only in the green plant parts. No transgenic protein expression was observed in the non-green parts, including roots, seeds and non-green floral tissues. Thus, leucoplasts may lack the mechanism to allow entry of a protein tagged with the transit peptide from a protein that is only synthesized in tissues containing mature plastids. Combining the two events through sexual crossing led to near additive levels of the toxin at 4–5 times the level currently used in the field. The two high expression events and their combination will allow for effective resistance management against lepidopteran insect pests, particularly Helicoverpa armigera, using a high dosage strategy. PMID:27391960

  2. Latching relay switch assembly

    SciTech Connect

    Duimstra, Frederick A.

    1991-01-01

    A latching relay switch assembly which includes a coil section and a switch or contact section. The coil section includes at least one permanent magnet and at least one electromagnet. The respective sections are, generally, arranged in separate locations or cavities in the assembly. The switch is latched by a permanent magnet assembly and selectively switched by an overriding electromagnetic assembly.

  3. Relay Support for the Mars Science Laboratory Mission

    NASA Technical Reports Server (NTRS)

    Edwards, Charles D. Jr,; Bell, David J.; Gladden, Roy E.; Ilott, Peter A.; Jedrey, Thomas C.; Johnston, M. Daniel; Maxwell, Jennifer L.; Mendoza, Ricardo; McSmith, Gaylon W.; Potts, Christopher L.; Schratz, Brian C.; Shihabi, Mazen M.; Srinivasan, Jeffrey M.; Varghese, Phillip; Sanders, Stephen S.; Denis, Michel

    2013-01-01

    The Mars Science Laboratory (MSL) mission landed the Curiosity Rover on the surface of Mars on August 6, 2012, beginning a one-Martian-year primary science mission. An international network of Mars relay orbiters, including NASA's 2001 Mars Odyssey Orbiter (ODY) and Mars Reconnaissance Orbiter (MRO), and ESA's Mars Express Orbiter (MEX), were positioned to provide critical event coverage of MSL's Entry, Descent, and Landing (EDL). The EDL communication plan took advantage of unique and complementary capabilities of each orbiter to provide robust information capture during this critical event while also providing low-latency information during the landing. Once on the surface, ODY and MRO have provided effectively all of Curiosity's data return from the Martian surface. The link from Curiosity to MRO incorporates a number of new features enabled by the Electra and Electra-Lite software-defined radios on MRO and Curiosity, respectively. Specifically, the Curiosity-MRO link has for the first time on Mars relay links utilized frequency-agile operations, data rates up to 2.048 Mb/s, suppressed carrier modulation, and a new Adaptive Data Rate algorithm in which the return link data rate is optimally varied throughout the relay pass based on the actual observed link channel characteristics. In addition to the baseline surface relay support by ODY and MRO, the MEX relay service has been verified in several successful surface relay passes, and MEX now stands ready to provide backup relay support should NASA's orbiters become unavailable for some period of time.

  4. Relay exchanges in elite short track speed skating.

    PubMed

    Hext, Andrew; Heller, Ben; Kelley, John; Goodwill, Simon

    2017-06-01

    In short track speed skating, the relay exchange provides an additional strategic component to races by allowing a team to change the skater involved in the pack race. Typically executed every 1½ laps, it is the belief of skaters and coaches that during this period of the race, time can be gained or lost due to the execution of the relay exchange. As such, the aim of this study was to examine the influence of the relay exchange on a team's progression through a 5000 m relay race. Using data collected from three World Cup relay events during the 2012-2013 season, the time taken to complete the straight for the scenarios with and without the relay exchange were compared at different skating speeds for the corner exit prior to the straight. Overall, the influence of the relay exchange was found to be dependent on this corner exit speed. At slower corner exit speeds (12.01-13.5 m/s), relay exchange straight times were significantly faster than the free skating scenario (P < 0.01). While at faster corner exit speeds (14.01-15 m/s), straight times were significantly slower (P < 0.001). The findings of this study suggest that the current norm of executing relay exchanges every 1½ laps may not be optimal. Instead, varying the frequency of relay exchange execution throughout the race could allow: (1) time to be gained relative to other teams; and (2) facilitate other race strategies by providing an improved opportunity to overtake.

  5. Adjustable electronic load-alarm relay

    DOEpatents

    Mason, Charles H.; Sitton, Roy S.

    1976-01-01

    This invention is an improved electronic alarm relay for monitoring the current drawn by an AC motor or other electrical load. The circuit is designed to measure the load with high accuracy and to have excellent alarm repeatability. Chattering and arcing of the relay contacts are minimal. The operator can adjust the set point easily and can re-set both the high and the low alarm points by means of one simple adjustment. The relay includes means for generating a signal voltage proportional to the motor current. In a preferred form of the invention a first operational amplifier is provided to generate a first constant reference voltage which is higher than a preselected value of the signal voltage. A second operational amplifier is provided to generate a second constant reference voltage which is lower than the aforementioned preselected value of the signal voltage. A circuit comprising a first resistor serially connected to a second resistor is connected across the outputs of the first and second amplifiers, and the junction of the two resistors is connected to the inverting terminal of the second amplifier. Means are provided to compare the aforementioned signal voltage with both the first and second reference voltages and to actuate an alarm if the signal voltage is higher than the first reference voltage or lower than the second reference voltage.

  6. Relaying an optical wavefront

    DOEpatents

    Sweatt, William C.; Vawter, G. Allen

    2007-03-06

    A wavefront rely devices samples an incoming optical wavefront at different locations, optically relays the samples while maintaining the relative position of the samples and the relative phase between the samples. The wavefront is reconstructed due to interference of the samples. Devices can be designed for many different wavelengths, including for example the ultraviolet, visible, infrared and even longer wavelengths such as millimeter waves. In one application, the device function as a telescope but with negligible length.

  7. 49 CFR 236.589 - Relays.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Relays. 236.589 Section 236.589 Transportation... Cab Signal Systems Inspection and Tests; Locomotive § 236.589 Relays. (a) Each relay shall be removed... such relay is designed to operate, as follows: (1) Master or primary relays of torque type depending...

  8. 49 CFR 236.589 - Relays.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Relays. 236.589 Section 236.589 Transportation... Cab Signal Systems Inspection and Tests; Locomotive § 236.589 Relays. (a) Each relay shall be removed... such relay is designed to operate, as follows: (1) Master or primary relays of torque type depending...

  9. 49 CFR 236.589 - Relays.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Relays. 236.589 Section 236.589 Transportation... Cab Signal Systems Inspection and Tests; Locomotive § 236.589 Relays. (a) Each relay shall be removed... such relay is designed to operate, as follows: (1) Master or primary relays of torque type depending...

  10. 49 CFR 236.589 - Relays.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Relays. 236.589 Section 236.589 Transportation... Cab Signal Systems Inspection and Tests; Locomotive § 236.589 Relays. (a) Each relay shall be removed... such relay is designed to operate, as follows: (1) Master or primary relays of torque type depending...

  11. 49 CFR 236.589 - Relays.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Relays. 236.589 Section 236.589 Transportation... Cab Signal Systems Inspection and Tests; Locomotive § 236.589 Relays. (a) Each relay shall be removed... such relay is designed to operate, as follows: (1) Master or primary relays of torque type depending...

  12. An overview of relay channels - Information theory of satellite data relay link

    NASA Astrophysics Data System (ADS)

    Iida, Takashi

    1987-03-01

    This paper gives an overview of the theory of the relay channel, the communication channel having a relay encoder between transmitter and receiver. The relay channel corresponds to a satellite data relay link. The basic problem of this theory is to find the channel capacity. The theory of the relay channel was introduced by Van der Meulen (1971) and was expanded by Cover and El Gamal (1979). This paper reviews the meaning of relay in communication, and discusses the general, degraded, Gaussian degraded, and feedback relay channels. Furthermore, the satellite data relay link is discussed in comparison with the relay channel theory.

  13. Radio Relays Improve Wireless Products

    NASA Technical Reports Server (NTRS)

    2009-01-01

    Signal Hill, California-based XCOM Wireless Inc. developed radio frequency micromachine (RF MEMS) relays with a Phase II Small Business Innovation Research (SBIR) contract through NASA?s Jet Propulsion Laboratory. In order to improve satellite communication systems, XCOM produced wireless RF MEMS relays and tunable capacitors that use metal-to-metal contact and have the potential to outperform most semiconductor technologies while using less power. These relays are used in high-frequency test equipment and instrumentation, where increased speed can mean significant cost savings. Applications now also include mainstream wireless applications and greatly improved tactical radios.

  14. Admittance relay helps wash out system instability

    SciTech Connect

    Sweezy, G.; Swift, G.; Zhang, Z.

    1996-01-01

    This article describes how delta-current admittance relays detect severe power system disturbances and initiate a power reduction signal on the dc transmission system to help stabilize the integrated ac/HVDC transmission system. It is always desirable to transmit as much power as possible over major transmission line interconnections, and the 500 kV line linking Manitoba in Canada to Minnesota in the US is a good example. A static var system (SVS) is part of this strategy. Note the southern end of an HVDC line through which the power is delivered from northern hydro-electric generation. The ability to quickly control dc-delivered power combined with the complication of SVS switching and the installation of series capacitors has led to special circumstances requiring an unusual approach to maintenance of system stability. The availability of a new protection-oriented computing platform has made the required algorithms feasible.

  15. 49 CFR 236.106 - Relays.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Relays. 236.106 Section 236.106 Transportation... Inspections and Tests; All Systems § 236.106 Relays. Each relay, the functioning of which affects the safety... centrifugal type relay shall be tested at least once every 12 months; (b) Alternating current vane type...

  16. 49 CFR 236.789 - Relay, timing.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Relay, timing. 236.789 Section 236.789... Relay, timing. A relay which will not close its front contacts or open its back contacts, or both, until the expiration of a definite time intervals after the relay has been energized....

  17. 49 CFR 236.789 - Relay, timing.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Relay, timing. 236.789 Section 236.789... Relay, timing. A relay which will not close its front contacts or open its back contacts, or both, until the expiration of a definite time intervals after the relay has been energized....

  18. 49 CFR 236.789 - Relay, timing.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Relay, timing. 236.789 Section 236.789... Relay, timing. A relay which will not close its front contacts or open its back contacts, or both, until the expiration of a definite time intervals after the relay has been energized....

  19. 49 CFR 236.789 - Relay, timing.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Relay, timing. 236.789 Section 236.789... Relay, timing. A relay which will not close its front contacts or open its back contacts, or both, until the expiration of a definite time intervals after the relay has been energized....

  20. 49 CFR 236.106 - Relays.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Relays. 236.106 Section 236.106 Transportation... Inspections and Tests; All Systems § 236.106 Relays. Each relay, the functioning of which affects the safety... centrifugal type relay shall be tested at least once every 12 months; (b) Alternating current vane type...

  1. 49 CFR 236.106 - Relays.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Relays. 236.106 Section 236.106 Transportation... Inspections and Tests; All Systems § 236.106 Relays. Each relay, the functioning of which affects the safety... centrifugal type relay shall be tested at least once every 12 months; (b) Alternating current vane type...

  2. 49 CFR 236.106 - Relays.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Relays. 236.106 Section 236.106 Transportation... Inspections and Tests; All Systems § 236.106 Relays. Each relay, the functioning of which affects the safety... centrifugal type relay shall be tested at least once every 12 months; (b) Alternating current vane type...

  3. 49 CFR 236.789 - Relay, timing.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Relay, timing. 236.789 Section 236.789... Relay, timing. A relay which will not close its front contacts or open its back contacts, or both, until the expiration of a definite time intervals after the relay has been energized....

  4. 49 CFR 236.106 - Relays.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Relays. 236.106 Section 236.106 Transportation... Inspections and Tests; All Systems § 236.106 Relays. Each relay, the functioning of which affects the safety... centrifugal type relay shall be tested at least once every 12 months; (b) Alternating current vane type...

  5. Laser Relay: Improving Space Communications

    NASA Video Gallery

    The Laser Communications Relay Demonstration mission proposes to revolutionize the way we send and receive data, video and other information, using lasers to encode and transmit data at rates 10 to...

  6. The power relay satellite

    SciTech Connect

    Glaser, P.E.

    1994-12-31

    The availability and use of renewable energy sources compatible with reducing risks to the global environment are key to sustainable development. Large-scale, renewable energy resources at undeveloped or underutilized sites are potentially available on several continents. The Power Relay Satellite (PRS) concept has the potential to access these remote energy resources by coupling primary electricity generation from terrestrial transmission lines. A global PRS network can be envisioned to provide a high degree of flexibility for supplying energy demands worldwide with wireless power transmitted from sites on Earth to geosynchronous orbit and then reflected to receivers interfacing with terrestrial power transmision networks. Past developments in wireless power transmission (WPT) are reviewed and recent successful results are noted. The origins of the PRS concept, and a possible configuration are discussed, principles of WPT at microwave frequencies, functional requirements, and system design contraints are outlined, and space transportation concepts presented. PRS assessments including applicable technologies, economic projections, and societal issues are highlighted. It is concluded that the PRS provides a promising option to access renewable resources at great distances from major markets, and represents an important stage in the future development in the future of solar power satellites.

  7. The power relay satellite

    NASA Astrophysics Data System (ADS)

    Glaser, Peter E.

    The availability and use of renewable energy sources compatible with reducing risks to the global environment are key to sustainable development. Large-scale, renewable energy resources at undeveloped or underutilized sites are potentially available on several continents. The Power Relay Satellite (PRS) concept has the potential to access these remote energy resources by coupling primary electricity generation from terrestrial transmission lines. A global PRS network can be envisioned to provide a high degree of flexibility for supplying energy demands worldwide with wireless power transmitted from sites on Earth to geosynchronous orbit and then reflected to receivers interfacing with terrestrial power transmision networks. Past developments in wireless power transmission (WPT) are reviewed and recent successful results are noted. The origins of the PRS concept, and a possible configuration are discussed, principles of WPT at microwave frequencies, functional requirements, and system design contraints are outlined, and space transportation concepts presented. PRS assessments including applicable technologies, economic projections, and societal issues are highlighted. It is concluded that the PRS provides a promising option to access renewable resources at great distances from major markets, and represents an important stage in the future development in the future of solar power satellites.

  8. PHOTOSENSITIVE RELAY CONTROL CIRCUIT

    DOEpatents

    Martin, C.F.

    1958-01-14

    adapted for the measurement of the time required for an oscillating member to pass through a preselected number of oscillations, after being damped to a certain maximum amplitude of oscillation. A mirror is attached to the moving member and directs light successively to a photocell which is part of a trigger unit and to first and second photocells which are part of a starter unit, as the member swings to its maximum amplitude. The starter and trigger units comprise thyratrons and relays so interconnected that the trigger circuit, although generating a counter pulse, does not register a count in the counter when the light traverses both photocells of the starter unit. When the amplitude of oscillation of the member decreases to where the second photocell is not transversed, the triggei pulse is received by the counter. The counter taen operates to register the desired number of oscillations and initiates and terminates a timer for measuring the time irterval for the preselected number of oscillations.

  9. Telecommunications Relay Support of the Mars Phoenix Lander Mission

    NASA Technical Reports Server (NTRS)

    Edwards, Charles D., Jr.; Erickson, James K.; Gladden, Roy E.; Guinn, Joseph R.; Ilott, Peter A.; Jai, Benhan; Johnston, Martin D.; Kornfeld, Richard P.; Martin-Mur, Tomas J.; McSmith, Gaylon W.; Thomas, Reid C.; Varghese, Phil; Signori, Gina; Schmitz, Peter

    2010-01-01

    The Phoenix Lander, first of NASA's Mars Scout missions, arrived at the Red Planet on May 25, 2008. From the moment the lander separated from its interplanetary cruise stage shortly before entry, the spacecraft could no longer communicate directly with Earth, and was instead entirely dependent on UHF relay communications via an international network of orbiting Mars spacecraft, including NASA's 2001 Mars Odyssey (ODY) and Mars Reconnaissance Orbiter (MRO) spacecraft, as well as ESA's Mars Express (MEX) spacecraft. All three orbiters captured critical event telemetry and/or tracking data during Phoenix Entry, Descent and Landing. During the Phoenix surface mission, ODY and MRO provided command and telemetry services, far surpassing the original data return requirements. The availability of MEX as a backup relay asset enhanced the robustness of the surface relay plan. In addition to telecommunications services, Doppler tracking observables acquired on the UHF link yielded an accurate position for the Phoenix landing site.

  10. EAGLE: relay mirror technology development

    NASA Astrophysics Data System (ADS)

    Hartman, Mary; Restaino, Sergio R.; Baker, Jeffrey T.; Payne, Don M.; Bukley, Jerry W.

    2002-06-01

    EAGLE (Evolutionary Air & Space Global Laser Engagement) is the proposed high power weapon system with a high power laser source, a relay mirror constellation, and the necessary ground and communications links. The relay mirror itself will be a satellite composed of two optically-coupled telescopes/mirrors used to redirect laser energy from ground, air, or space based laser sources to distant points on the earth or space. The receiver telescope captures the incoming energy, relays it through an optical system that cleans up the beam, then a separate transmitter telescope/mirror redirects the laser energy at the desired target. Not only is it a key component in extending the range of DoD's current laser weapon systems, it also enables ancillary missions. Furthermore, if the vacuum of space is utilized, then the atmospheric effects on the laser beam propagation will be greatly attenuated. Finally, several critical technologies are being developed to make the EAGLE/Relay Mirror concept a reality, and the Relay Mirror Technology Development Program was set up to address them. This paper will discuss each critical technology, the current state of the work, and the future implications of this program.

  11. Sealed reed relay limit switches

    NASA Astrophysics Data System (ADS)

    Ivanov, I. P.; Svintsov, G. P.; Yefimova, M. A.; Lebedev, A. V.; Samsonov, Y. P.

    1986-01-01

    Sealed reed relay limit switches are described which overcome the inherent deficiencies traditionally present in these devices: high material, labor consumption, and difficult operation. Series VSG limit switches developed at the All-Union Scientific Research and Technological Planning Institute for Relay Engineering (Cheboksary) for use in buildings are described. The VSG1 has a single switching contact, the VSG2 a single normally open contact, and the VSG3 a single normally closed contact. The VSG1 employs type MKS-27103 sealed reed relays, while the VSG2 and VSG3 employ KEM-1 reed relays. The magnet system, which consists of magnets and a plate, and the sealed reed relay are contained in a nonmagnetic casing with a slit in it. The mathematical expression defining the geometric dimensions of the magnet system is given. The basic parameteres of all three types of switches are tabulated. The VSG series switches can be used to replace VBK and BVK switches, thus saving electricity, labor, and materials, including silver.

  12. Satellite Relaying of Geophysical Data

    NASA Technical Reports Server (NTRS)

    Allenby, R. J.

    1977-01-01

    Data Collection Platforms (DCPs) for transmitting surface data to an orbiting satellite for relaying to a central data distribution center are being used in a number of geophysical applications. "Off-the-shelf" DCP's, transmitting through Landsat or GOES satellites, are fully capable of relaying data from low-data-rate instruments, such as tiltmeters or tide gauges. In cooperation with the Lamont-Doherty Geological Observatory, Goddard has successfully installed DCP systems on a tide gauge and tiltmeter array on Anegada, British Virgin Islands. Because of the high-data-rate requirements, a practical relay system capable of handling seismic information is not yet available. Such a system could become the basis of an operational hazard prediction system for reducing losses due to major natural catastrophies such as earthquakes, volcanic eruptions, landslides or tsunamis.

  13. Speech-to-Speech Relay Service

    MedlinePlus

    ... Speech-to-Speech (STS) is one form of Telecommunications Relay Service (TRS). TRS is a service that ... to STS, go to www. fcc. gov/ guides/ telecommunications- relay- service- trs. Filing a Complaint If you ...

  14. Performance limitations of relay neurons.

    PubMed

    Agarwal, Rahul; Sarma, Sridevi V

    2012-01-01

    Relay cells are prevalent throughout sensory systems and receive two types of inputs: driving and modulating. The driving input contains receptive field properties that must be transmitted while the modulating input alters the specifics of transmission. For example, the visual thalamus contains relay neurons that receive driving inputs from the retina that encode a visual image, and modulating inputs from reticular activating system and layer 6 of visual cortex that control what aspects of the image will be relayed back to visual cortex for perception. What gets relayed depends on several factors such as attentional demands and a subject's goals. In this paper, we analyze a biophysical based model of a relay cell and use systems theoretic tools to construct analytic bounds on how well the cell transmits a driving input as a function of the neuron's electrophysiological properties, the modulating input, and the driving signal parameters. We assume that the modulating input belongs to a class of sinusoidal signals and that the driving input is an irregular train of pulses with inter-pulse intervals obeying an exponential distribution. Our analysis applies to any [Formula: see text] order model as long as the neuron does not spike without a driving input pulse and exhibits a refractory period. Our bounds on relay reliability contain performance obtained through simulation of a second and third order model, and suggest, for instance, that if the frequency of the modulating input increases or the DC offset decreases, then relay increases. Our analysis also shows, for the first time, how the biophysical properties of the neuron (e.g. ion channel dynamics) define the oscillatory patterns needed in the modulating input for appropriately timed relay of sensory information. In our discussion, we describe how our bounds predict experimentally observed neural activity in the basal ganglia in (i) health, (ii) in Parkinson's disease (PD), and (iii) in PD during therapeutic deep

  15. 78 FR 40581 - Structure and Practices of the Video Relay Service Program; Telecommunications Relay Services and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-05

    ... Video Relay Service Program; Telecommunications Relay Services and Speech-to-Speech Services for Individuals With Hearing and Speech Disabilities; Final Rule #0;#0;Federal Register / Vol. 78, No. 129... Structure and Practices of the Video Relay Service Program; Telecommunications Relay Services and...

  16. 49 CFR 234.263 - Relays.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Relays. 234.263 Section 234.263 Transportation... SYSTEMS Maintenance, Inspection, and Testing Inspections and Tests § 234.263 Relays. (a) Except as stated in paragraph (b) of this section, each relay that affects the proper functioning of a...

  17. 49 CFR 234.263 - Relays.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Relays. 234.263 Section 234.263 Transportation... SYSTEMS Maintenance, Inspection, and Testing Inspections and Tests § 234.263 Relays. (a) Except as stated in paragraph (b) of this section, each relay that affects the proper functioning of a...

  18. 49 CFR 234.263 - Relays.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Relays. 234.263 Section 234.263 Transportation... SYSTEMS Maintenance, Inspection, and Testing Inspections and Tests § 234.263 Relays. (a) Except as stated in paragraph (b) of this section, each relay that affects the proper functioning of a...

  19. Relay Writing in an Adolescent Online Community

    ERIC Educational Resources Information Center

    Yi, Youngjoo

    2008-01-01

    "Welcome to Buckeye City" is an adolescent online community that was maintained by 25 Korean students who attended American schools. On the website, the students engaged in "relay writing"--a writing activity in which each person contributed a portion of an evolving story in a relayed manner. Relay writing offers teachers a new and valuable window…

  20. Signal Relay During Cell Migration

    NASA Astrophysics Data System (ADS)

    Guven, Can; Rericha, Erin; Ott, Edward; Losert, Wolfgang

    2012-02-01

    We developed a signal relay model to quantify the effect of intercellular communication in presence of an external signal, during the motion of groups of Dictyostelium discoideum cells. A key parameter is the ratio of amplitude of the cAMP (cyclic adenosine monophosphate) a signaling chemical secreted from individual cells versus the external cAMP field, which defines a time scale. Another time scale is set by the degradation rate of the cAMP. In our simulations, the competition between these two time scales results rich dynamics including uniform motion, as well as streaming and clustering instabilities. The simulations are compared to experiments for a wide range of different external signal strengths for both cells that secrete cAMP and a mutant which cannot relay cAMP. Under different strength of external linear cAMP gradient, the wild type cells form streams and exhibit clustering due to the intercellular signaling through individual cAMP secretion. In contrast, cells lacking signal relay move relatively straight. We find that the model captures both independent motion and the formation of aggregates when cells relay the signal.

  1. STBC AF relay for unmanned aircraft system

    NASA Astrophysics Data System (ADS)

    Adachi, Fumiyuki; Miyazaki, Hiroyuki; Endo, Chikara

    2015-01-01

    If a large scale disaster similar to the Great East Japan Earthquake 2011 happens, some areas may be isolated from the communications network. Recently, unmanned aircraft system (UAS) based wireless relay communication has been attracting much attention since it is able to quickly re-establish the connection between isolated areas and the network. However, the channel between ground station (GS) and unmanned aircraft (UA) is unreliable due to UA's swing motion and as consequence, the relay communication quality degrades. In this paper, we introduce space-time block coded (STBC) amplify-and-forward (AF) relay for UAS based wireless relay communication to improve relay communication quality. A group of UAs forms single frequency network (SFN) to perform STBC-AF cooperative relay. In STBC-AF relay, only conjugate operation, block exchange and amplifying are required at UAs. Therefore, STBC-AF relay improves the relay communication quality while alleviating the complexity problem at UAs. It is shown by computer simulation that STBC-AF relay can achieve better throughput performance than conventional AF relay.

  2. The magic of relay mirrors

    NASA Astrophysics Data System (ADS)

    Duff, Edward A.; Washburn, Donald C.

    2004-09-01

    Laser weapon systems would be significantly enhanced with the addition of high altitude or space-borne relay mirrors. Such mirrors, operating alone with a directed energy source, or many in a series fashion, can be shown to effectively move the laser source to the last, so-called fighting mirror. This "magically" reduces the range to target and offers to enhance the performance of directed energy systems like the Airborne Laser and even ground-based or ship-based lasers. Recent development of high altitude airships will be shown to provide stationary positions for such relay mirrors thereby enabling many new and important applications for laser weapons. The technical challenges to achieve this capability are discussed.

  3. On information flow in relay networks

    NASA Astrophysics Data System (ADS)

    El Gamal, A.

    Preliminary investigations conducted by El Gamal and Cover (1980) have shown that a max-flow min-cut interpretation for the capacity expressions of the classes of degraded and semideterministic relay channels can be found. In this paper it is shown that such an interpretation can also be found for fairly general classes of discrete memoryless relay networks. Cover and El Gamal (1979) have obtained general lower and upper bounds to capacity. However, the capacity of the general relay channel is not known. Past results are here extended to establish the capacity of deterministic relay networks with no interference and degraded relay networks. A general upper bound is given to the capacity of any relay network with this upper bound being a natural generalization of Theorem 4 in the study conducted by Cover and El Gamal (1979).

  4. The Laser Communications Relay and the Path to the Next Generation Near Earth Relay

    NASA Technical Reports Server (NTRS)

    Israel, David J.

    2015-01-01

    NASA Goddard Space Flight Center is currently developing the Laser Communications Relay Demonstration (LCRD) as a Path to the Next Generation Near Earth Space Communication Network. The current NASA Space Network or Tracking and Data Relay Satellite System is comprised of a constellation of Tracking and Data Relay Satellites (TDRS) in geosynchronous orbit and associated ground stations and operation centers. NASA is currently targeting a next generation of relay capability on orbit in the 2025 timeframe.

  5. Inhomogeneity induces relay synchronization in complex networks

    NASA Astrophysics Data System (ADS)

    Gambuzza, Lucia Valentina; Frasca, Mattia; Fortuna, Luigi; Boccaletti, Stefano

    2016-04-01

    Relay synchronization is a collective state, originally found in chains of interacting oscillators, in which uncoupled dynamical units synchronize through the action of mismatched inner nodes that relay the information but do not synchronize with them. It is demonstrated herein that relay synchronization is not limited to such simple motifs, rather it can emerge in larger and arbitrary network topologies. In particular, we show how this phenomenon can be observed in networks of chaotic systems in the presence of some mismatched units, the relay nodes, and how it is actually responsible for an enhancement of synchronization in the network.

  6. Inhomogeneity induces relay synchronization in complex networks.

    PubMed

    Gambuzza, Lucia Valentina; Frasca, Mattia; Fortuna, Luigi; Boccaletti, Stefano

    2016-04-01

    Relay synchronization is a collective state, originally found in chains of interacting oscillators, in which uncoupled dynamical units synchronize through the action of mismatched inner nodes that relay the information but do not synchronize with them. It is demonstrated herein that relay synchronization is not limited to such simple motifs, rather it can emerge in larger and arbitrary network topologies. In particular, we show how this phenomenon can be observed in networks of chaotic systems in the presence of some mismatched units, the relay nodes, and how it is actually responsible for an enhancement of synchronization in the network.

  7. 49 CFR 236.311 - Signal control circuits, selection through track relays or devices functioning as track relays...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... relays or devices functioning as track relays and through signal mechanism contacts and time releases at... relays or devices functioning as track relays and through signal mechanism contacts and time releases at... at restricted speed” shall be selected through track relays, or through devices that function...

  8. 49 CFR 236.311 - Signal control circuits, selection through track relays or devices functioning as track relays...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... relays or devices functioning as track relays and through signal mechanism contacts and time releases at... relays or devices functioning as track relays and through signal mechanism contacts and time releases at... at restricted speed” shall be selected through track relays, or through devices that function...

  9. 49 CFR 236.311 - Signal control circuits, selection through track relays or devices functioning as track relays...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... relays or devices functioning as track relays and through signal mechanism contacts and time releases at... relays or devices functioning as track relays and through signal mechanism contacts and time releases at... at restricted speed” shall be selected through track relays, or through devices that function...

  10. 49 CFR 236.311 - Signal control circuits, selection through track relays or devices functioning as track relays...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... relays or devices functioning as track relays and through signal mechanism contacts and time releases at... relays or devices functioning as track relays and through signal mechanism contacts and time releases at... at restricted speed” shall be selected through track relays, or through devices that function...

  11. 49 CFR 236.311 - Signal control circuits, selection through track relays or devices functioning as track relays...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... relays or devices functioning as track relays and through signal mechanism contacts and time releases at... relays or devices functioning as track relays and through signal mechanism contacts and time releases at... at restricted speed” shall be selected through track relays, or through devices that function...

  12. Scheduler software for tracking and data relay satellite system loading analysis: User manual and programmer guide

    NASA Technical Reports Server (NTRS)

    Craft, R.; Dunn, C.; Mccord, J.; Simeone, L.

    1980-01-01

    A user guide and programmer documentation is provided for a system of PRIME 400 minicomputer programs. The system was designed to support loading analyses on the Tracking Data Relay Satellite System (TDRSS). The system is a scheduler for various types of data relays (including tape recorder dumps and real time relays) from orbiting payloads to the TDRSS. Several model options are available to statistically generate data relay requirements. TDRSS time lines (representing resources available for scheduling) and payload/TDRSS acquisition and loss of sight time lines are input to the scheduler from disk. Tabulated output from the interactive system includes a summary of the scheduler activities over time intervals specified by the user and overall summary of scheduler input and output information. A history file, which records every event generated by the scheduler, is written to disk to allow further scheduling on remaining resources and to provide data for graphic displays or additional statistical analysis.

  13. Joint Source-Relay Design for Full-Duplex MIMO AF Relay Systems

    NASA Astrophysics Data System (ADS)

    Shi, Qingjiang; Hong, Mingyi; Gao, Xiqi; Song, Enbin; Cai, Yunlong; Xu, Weiqiang

    2016-12-01

    The performance of full-duplex (FD) relay systems can be greatly impacted by the self-interference (SI) at relays. By exploiting multi-antenna in FD relay systems, the spectral efficiency of FD relay systems can be enhanced through spatial SI mitigation. This paper studies joint source transmit beamforming and relay processing to achieve rate maximization for FD MIMO amplify-and-forward (AF) relay systems with consideration of relay processing delay. The problem is difficult to solve due mainly to the SI constraint induced by the relay processing delay. In this paper, we first present a sufficient condition under which the relay amplification matrix has rank one structure. Then, for the case of rank one amplification matrix, the rate maximization problem is equivalently simplified into an unconstrained problem which can be locally solved using gradient ascent method. Next, we propose a penalty-based algorithmic framework, called P-BSUM, for a class of constrained optimization problems which have difficult equality constraints in addition to some convex constraints. By rewriting the rate maximization problem with a set of auxiliary variables, we apply the P-BSUM algorithm to the rate maximization problem in the general case. Finally, numerical results validate the efficiency of the proposed algorithms and show that the joint source-relay design approach under the rank one assumption could be strictly suboptimal as compared to the P-BSUM-based joint source-relay design approach.

  14. A model of thalamocortical relay cells.

    PubMed

    Rhodes, Paul A; Llinás, Rodolfo

    2005-06-15

    It is well established that the main intrinsic electrophysiological properties of thalamocortical relay cells, production of a low threshold burst upon release from hyperpolarized potential and production of a train of single spikes following stimulation from depolarized potentials, can be readily modelled using a single compartment. There is, however, another less well explored intrinsic electrophysiological characteristic of relay cells for which models have not yet accounted: at somatic potentials near spike threshold, relay cells produce a fast ragged high threshold oscillation in somatic voltage. Optical [Ca(2+)] imaging and pharmacological tests indicate that this oscillation correlates with a high threshold Ca(2+) current in the dendrites. Here we present the development of a new compartment model of the thalamic relay cell guided by the simultaneous constraints that it must produce the familiar regular spiking relay mode and low threshold rebound bursts which characterize these cells, as well as the less-studied fast oscillation occurring at near-threshold somatic potentials. We arrive at a model cell which is capable of the production of isolated high threshold Ca(2+) spikes in distal branch segments, driven by a rapidly inactivating intermediate threshold Ca(2+) channel. Further, the model produces the low threshold spike behaviour of the relay cell without requiring high T-current density in the distal dendritic segments. The results thus support a new picture of the dendritic tree of relay cells which may have implications for the manner in which thalamic relay cells integrate descending input from the cortex.

  15. An adaptive out-of-step relay

    SciTech Connect

    Centeno, V.; Phadke, A.G.; Edris, A.; Benton, J.; Gaudi, M.; Michel, G.

    1997-01-01

    The paper describes the development of an adaptive out-of-step relay, from the formulation of its concept to its field implementation at the Florida-Georgia interface. Adaptive relaying seeks to make adjustments to the relay characteristics as system conditions change, thereby making the relay more attuned to the prevailing power system conditions. The work described here began as a theoretical examination of the out-of-step relaying application, its possible shortcomings, and the opportunities to make adaptive improvements. It is shown that for a system that behaves primarily as a two-machine power system, the out-of-step relay could be made more secure by applying the principle of equal area criterion. The paper describes the theory of such a relay, its hardware configuration, and the system as it is installed in the field. The newly developed technology of synchronized phasor measurements plays an important role in the realization of this relay. The paper includes a summary of the field experience gathered over a period of one year.

  16. Simple circuit monitors "third wire" in ac lines

    NASA Technical Reports Server (NTRS)

    Kojima, T. T.; Stuck, D. E.

    1980-01-01

    Device detects interruption of ground connection in three-wire electrical equipment and shuts off ac power to prevent shock hazard. Silicon-controlled rectifiers detect floating ground, and deenergize optoelectric relays thereby breaking power connections. Circuit could be incorporated into hand tools, appliances, and other electrical equipment.

  17. G. Marconi: A Data Relay Satellite for Mars Communications

    NASA Astrophysics Data System (ADS)

    Dionisio, C.; Marcozzi, M.; Landriani, C.

    2002-01-01

    Mars has always been a source of intrigue and fascination. Recent scientific discoveries have stimulated this longstanding interest, leading to a renaissance in Mars exploration. Future missions to Mars will be capable of long-distance surface mobility, hyperspectral imaging, subsurface exploration, and even life-detection. Manned missions and, eventually, colonies may follow. No mission to the Red Planet stands alone. New scientific and technological knowledge is passed on from one mission to the next, not only improving the journey into space, but also providing benefits here on Earth. The Mars Relay Network, an international constellation of Mars orbiters with relay radios, directly supports other Mars missions by relaying communications between robotic vehicles at Mars and ground stations on Earth. The ability of robotic visitors from Earth to explore Mars will take a gigantic leap forward in 2007 with the launch of the Guglielmo Marconi Orbiter (GMO), the first spacecraft primarily dedicated to providing communication relay, navigation and timing services at Mars. GMO will be the preeminent node of the Mars Relay Network. GMO will relay communications between Earth and robotic vehicles near Mars. GMO will also provide navigation services to spacecraft approaching Mars. GMO will receive transmissions from ground stations on Earth at X-band and will transmit to ground stations on Earth at X- and Ka-bands. GMO will transmit to robotic vehicles at Mars at UHF and receive from these vehicles at UHF and X-band. GMO's baseline 4450 km circular orbit provides complete coverage of the planet for telecommunication and navigation support. GMO will arrive at Mars in mid-2008, just before the NetLander and Mars Scout missions that will be its first users. GMO is designed for a nominal operating lifetime of 10 years and will support nominal commanding and data acquisition, as well as mission critical events such as Mars Orbit Insertion, Entry, Descent and Landing, and Mars

  18. Feature-linked synchronization of thalamic relay cell firing induced by feedback from the visual cortex

    NASA Astrophysics Data System (ADS)

    Sillito, Adam M.; Jones, Helen E.; Gerstein, George L.; West, David C.

    1994-06-01

    THE function of the massive feedback projection from visual cortex to its thalamic relay nucleus1,2 has so far eluded any clear overview. This feedback exerts a range of effects3-6, including an increase in the inhibition elicited by moving contours7,8, but the functional logic of the direct connections to the thalamic cells that relay the retinal input to the cortex9-11 remains largely unknown. In contrast to its thalamic nucleus, the visual cortex is characterized by cells that are strongly sensitive to the orientation of moving contours. Here we report that when driven by moving oriented visual stimuli the cortical feedback induces correlated firing in relay cells. This cortically induced correlation of relay cell activity produces coherent firing in those groups of relay cells with receptive field alignments appropriate to signalling the particular orientation of the moving contour to the cortex. Synchronization of relay cell firing means that they will elicit temporally overlapping excitatory postsynaptic potentials in their cortical target cells, thus increasing the chance that the cortical cells will fire. Effectively this increases the gain of the input for feature-linked events detected by the cortex. We propose that this feedback loop serves to lock or focus the appropriate circuitry onto the stimulus feature.

  19. Evolution of a radio communication relay system

    NASA Astrophysics Data System (ADS)

    Nguyen, Hoa G.; Pezeshkian, Narek; Hart, Abraham; Burmeister, Aaron; Holz, Kevin; Neff, Joseph; Roth, Leif

    2013-05-01

    Providing long-distance non-line-of-sight control for unmanned ground robots has long been recognized as a problem, considering the nature of the required high-bandwidth radio links. In the early 2000s, the DARPA Mobile Autonomous Robot Software (MARS) program funded the Space and Naval Warfare Systems Center (SSC) Pacific to demonstrate a capability for autonomous mobile communication relaying on a number of Pioneer laboratory robots. This effort also resulted in the development of ad hoc networking radios and software that were later leveraged in the development of a more practical and logistically simpler system, the Automatically Deployed Communication Relays (ADCR). Funded by the Joint Ground Robotics Enterprise and internally by SSC Pacific, several generations of ADCR systems introduced increasingly more capable hardware and software for automatic maintenance of communication links through deployment of static relay nodes from mobile robots. This capability was finally tapped in 2010 to fulfill an urgent need from theater. 243 kits of ruggedized, robot-deployable communication relays were produced and sent to Afghanistan to extend the range of EOD and tactical ground robots in 2012. This paper provides a summary of the evolution of the radio relay technology at SSC Pacific, and then focuses on the latest two stages, the Manually-Deployed Communication Relays and the latest effort to automate the deployment of these ruggedized and fielded relay nodes.

  20. Lightweight Distance Bounding Protocol against Relay Attacks

    NASA Astrophysics Data System (ADS)

    Kim, Jin Seok; Cho, Kookrae; Yum, Dae Hyun; Hong, Sung Je; Lee, Pil Joong

    Traditional authentication protocols are based on cryptographic techniques to achieve identity verification. Distance bounding protocols are an enhanced type of authentication protocol built upon both signal traversal time measurement and cryptographic techniques to accomplish distance verification as well as identity verification. A distance bounding protocol is usually designed to defend against the relay attack and the distance fraud attack. As there are applications to which the distance fraud attack is not a serious threat, we propose a streamlined distance bounding protocol that focuses on the relay attack. The proposed protocol is more efficient than previous protocols and has a low false acceptance rate under the relay attack.

  1. Experimental service of 3DTV broadcasting relay in Korea

    NASA Astrophysics Data System (ADS)

    Hur, Namho; Ahn, Chung-Hyun; Ahn, Chieteuk

    2002-11-01

    This paper introduces 3D HDTV relay broadcasting experiments of 2002 FIFA World Cup Korea/Japan using a terrestrial and satellite network. We have developed 3D HDTV cameras, 3D HDTV video multiplexer/demultiplexer, a 3D HDTV receiver, and a 3D HDTV OB van for field productions. By using a terrestrial and satellite network, we distributed a compressed 3D HDTV signal to predetermined demonstration venues which are approved by host broadcast services (HBS), KirchMedia, and FIFA. In this case, we transmitted a 40Mbps MPEG-2 transport stream (DVB-ASI) over a DS-3 network specified in ITU-T Rec. G.703. The video/audio compression formats are MPEG-2 main-profile, high-level and Dolby Digital AC-3 respectively. Then at venues, the recovered left and right images by the 3D HDTV receiver are displayed on a screen with polarized beam projectors.

  2. 49 CFR 236.52 - Relayed cut-section.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Relayed cut-section. 236.52 Section 236.52...: All Systems Track Circuits § 236.52 Relayed cut-section. Where relayed cut-section is used in... shall be open and the track circuit shunted when the track relay at such cut-section is in...

  3. 49 CFR 236.52 - Relayed cut-section.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Relayed cut-section. 236.52 Section 236.52...: All Systems Track Circuits § 236.52 Relayed cut-section. Where relayed cut-section is used in... shall be open and the track circuit shunted when the track relay at such cut-section is in...

  4. 49 CFR 234.265 - Timing relays and timing devices.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Timing relays and timing devices. 234.265 Section....265 Timing relays and timing devices. Each timing relay and timing device shall be tested at least... or marked on the timing relay or timing device. Timing devices which perform internal...

  5. 49 CFR 234.265 - Timing relays and timing devices.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Timing relays and timing devices. 234.265 Section....265 Timing relays and timing devices. Each timing relay and timing device shall be tested at least... or marked on the timing relay or timing device. Timing devices which perform internal...

  6. 49 CFR 234.265 - Timing relays and timing devices.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Timing relays and timing devices. 234.265 Section....265 Timing relays and timing devices. Each timing relay and timing device shall be tested at least... or marked on the timing relay or timing device. Timing devices which perform internal...

  7. Using Internet Relay Chat in Teaching Chinese.

    ERIC Educational Resources Information Center

    Xie, Tianwei

    2002-01-01

    Explored the feasibility of using Internet Relay Chat (IRC) to facilitate Chinese language teaching and learning. Describes procedures for organizing and conducting chat sessions and discusses the benefits and problems of using IRC. (Author/VWL)

  8. Evolution of a Radio Communication Relay System

    DTIC Science & Technology

    2013-05-01

    communication relays were produced and sent to Afghanistan to extend the range of EOD and tactical ground robots in 2012. This paper provides a summary of the...to extend the range of EOD and tactical ground robots in 2012. This paper provides a summary of the evolution of the radio relay technology at SSC...unmanned ground robots has long been recognized as a problem, considering the nature of the required high-bandwidth radio links. In the early 2000s, the

  9. Physical Layer Security Using Two-Path Successive Relaying

    PubMed Central

    Liau, Qian Yu; Leow, Chee Yen; Ding, Zhiguo

    2016-01-01

    Relaying is one of the useful techniques to enhance wireless physical-layer security. Existing literature shows that employing full-duplex relay instead of conventional half-duplex relay improves secrecy capacity and secrecy outage probability, but this is at the price of sophisticated implementation. As an alternative, two-path successive relaying has been proposed to emulate operation of full-duplex relay by scheduling a pair of half-duplex relays to assist the source transmission alternately. However, the performance of two-path successive relaying in secrecy communication remains unexplored. This paper proposes a secrecy two-path successive relaying protocol for a scenario with one source, one destination and two half-duplex relays. The relays operate alternately in a time division mode to forward messages continuously from source to destination in the presence of an eavesdropper. Analytical results reveal that the use of two half-duplex relays in the proposed scheme contributes towards a quadratically lower probability of interception compared to full-duplex relaying. Numerical simulations show that the proposed protocol achieves the ergodic achievable secrecy rate of full-duplex relaying while delivering the lowest probability of interception and secrecy outage probability compared to the existing half duplex relaying, full duplex relaying and full duplex jamming schemes. PMID:27294924

  10. Physical Layer Security Using Two-Path Successive Relaying.

    PubMed

    Liau, Qian Yu; Leow, Chee Yen; Ding, Zhiguo

    2016-06-09

    Relaying is one of the useful techniques to enhance wireless physical-layer security. Existing literature shows that employing full-duplex relay instead of conventional half-duplex relay improves secrecy capacity and secrecy outage probability, but this is at the price of sophisticated implementation. As an alternative, two-path successive relaying has been proposed to emulate operation of full-duplex relay by scheduling a pair of half-duplex relays to assist the source transmission alternately. However, the performance of two-path successive relaying in secrecy communication remains unexplored. This paper proposes a secrecy two-path successive relaying protocol for a scenario with one source, one destination and two half-duplex relays. The relays operate alternately in a time division mode to forward messages continuously from source to destination in the presence of an eavesdropper. Analytical results reveal that the use of two half-duplex relays in the proposed scheme contributes towards a quadratically lower probability of interception compared to full-duplex relaying. Numerical simulations show that the proposed protocol achieves the ergodic achievable secrecy rate of full-duplex relaying while delivering the lowest probability of interception and secrecy outage probability compared to the existing half duplex relaying, full duplex relaying and full duplex jamming schemes.

  11. Airborne Relay-Based Regional Positioning System

    PubMed Central

    Lee, Kyuman; Noh, Hongjun; Lim, Jaesung

    2015-01-01

    Ground-based pseudolite systems have some limitations, such as low vertical accuracy, multipath effects and near-far problems. These problems are not significant in airborne-based pseudolite systems. However, the monitoring of pseudolite positions is required because of the mobility of the platforms on which the pseudolites are mounted, and this causes performance degradation. To address these pseudolite system limitations, we propose an airborne relay-based regional positioning system that consists of a master station, reference stations, airborne relays and a user. In the proposed system, navigation signals are generated from the reference stations located on the ground and are relayed via the airborne relays. Unlike in conventional airborne-based systems, the user in the proposed system sequentially estimates both the locations of airborne relays and his/her own position. Therefore, a delay due to monitoring does not occur, and the accuracy is not affected by the movement of airborne relays. We conducted several simulations to evaluate the performance of the proposed system. Based on the simulation results, we demonstrated that the proposed system guarantees a higher accuracy than airborne-based pseudolite systems, and it is feasible despite the existence of clock offsets among reference stations. PMID:26029953

  12. Performance analysis of relay subset selection for amplify-and-forward cognitive relay networks.

    PubMed

    Sultan, Kiran; Qureshi, Ijaz Mansoor; Malik, Aqdas Naveed; Zubair, Muhammad

    2014-01-01

    Cooperative communication is regarded as a key technology in wireless networks, including cognitive radio networks (CRNs), which increases the diversity order of the signal to combat the unfavorable effects of the fading channels, by allowing distributed terminals to collaborate through sophisticated signal processing. Underlay CRNs have strict interference constraints towards the secondary users (SUs) active in the frequency band of the primary users (PUs), which limits their transmit power and their coverage area. Relay selection offers a potential solution to the challenges faced by underlay networks, by selecting either single best relay or a subset of potential relay set under different design requirements and assumptions. The best relay selection schemes proposed in the literature for amplify-and-forward (AF) based underlay cognitive relay networks have been very well studied in terms of outage probability (OP) and bit error rate (BER), which is deficient in multiple relay selection schemes. The novelty of this work is to study the outage behavior of multiple relay selection in the underlay CRN and derive the closed-form expressions for the OP and BER through cumulative distribution function (CDF) of the SNR received at the destination. The effectiveness of relay subset selection is shown through simulation results.

  13. Transmission line relay mis-operation detection based on time-synchronized field data

    DOE PAGES

    Esmaeilian, Ahad; Popovic, Tomo; Kezunovic, Mladen

    2015-05-04

    In this paper, a real-time tool to detect transmission line relay mis-operation is implemented. The tool uses time-synchronized measurements obtained from both ends of the line during disturbances. The proposed fault analysis tool comes into the picture only after the protective device has operated and tripped the line. The proposed methodology is able not only to detect, classify, and locate transmission line faults, but also to accurately confirm whether the line was tripped due to a mis-operation of protective relays. The analysis report includes either detailed description of the fault type and location or detection of relay mis-operation. As such,more » it can be a source of very useful information to support the system restoration. The focus of the paper is on the implementation requirements that allow practical application of the methodology, which is illustrated using the field data obtained the real power system. Testing and validation is done using the field data recorded by digital fault recorders and protective relays. The test data included several hundreds of event records corresponding to both relay mis-operations and actual faults. The discussion of results addresses various challenges encountered during the implementation and validation of the presented methodology.« less

  14. Transmission line relay mis-operation detection based on time-synchronized field data

    SciTech Connect

    Esmaeilian, Ahad; Popovic, Tomo; Kezunovic, Mladen

    2015-05-04

    In this paper, a real-time tool to detect transmission line relay mis-operation is implemented. The tool uses time-synchronized measurements obtained from both ends of the line during disturbances. The proposed fault analysis tool comes into the picture only after the protective device has operated and tripped the line. The proposed methodology is able not only to detect, classify, and locate transmission line faults, but also to accurately confirm whether the line was tripped due to a mis-operation of protective relays. The analysis report includes either detailed description of the fault type and location or detection of relay mis-operation. As such, it can be a source of very useful information to support the system restoration. The focus of the paper is on the implementation requirements that allow practical application of the methodology, which is illustrated using the field data obtained the real power system. Testing and validation is done using the field data recorded by digital fault recorders and protective relays. The test data included several hundreds of event records corresponding to both relay mis-operations and actual faults. The discussion of results addresses various challenges encountered during the implementation and validation of the presented methodology.

  15. Quantum network with trusted and untrusted relays

    NASA Astrophysics Data System (ADS)

    Ma, Xiongfeng; Annabestani, Razieh; Fung, Chi-Hang Fred; Lo, Hoi-Kwong; Lütkenhaus, Norbert; PitkäNen, David; Razavi, Mohsen

    2012-02-01

    Quantum key distribution offers two distant users to establish a random secure key by exploiting properties of quantum mechanics, whose security has proven in theory. In practice, many lab and field demonstrations have been performed in the last 20 years. Nowadays, quantum network with quantum key distribution systems are tested around the world, such as in China, Europe, Japan and US. In this talk, I will give a brief introduction of recent development for quantum network. For the untrusted relay part, I will introduce the measurement-device-independent quantum key distribution scheme and a quantum relay with linear optics. The security of such scheme is proven without assumptions on the detection devices, where most of quantum hacking strategies are launched. This scheme can be realized with current technology. For the trusted relay part, I will introduce so-called delayed privacy amplification, with which no error correction and privacy amplification is necessarily to be performed between users and the relay. In this way, classical communications and computational power requirement on the relay site will be reduced.

  16. COMPASS Final Report: Lunar Relay Satellite (LRS)

    NASA Technical Reports Server (NTRS)

    Oleson, Steven R.; McGuire, Melissa L.

    2012-01-01

    The Lunar Relay Satellite (LRS) COllaborative Modeling and Parametric Assessment of Space Systems (COMPASS) session was tasked to design a satellite to orbit in an elliptical lunar polar orbit to provide relay communications between lunar South Pole assets and the Earth. The design included a complete master equipment list, power requirement list, configuration design, and brief risk assessment and cost analysis. The LRS is a half-TDRSS sized box spacecraft, which provides communications and navigation relay between lunar outposts (via Lunar Communications Terminals (LCT)) or Sortie parties (with user radios) and large ground antennas on Earth. The LRS consists of a spacecraft containing all the communications and avionics equipment designed by NASA Jet Propulsion Laboratory s (JPL) Team X to perform the relay between lunar-based assets and the Earth. The satellite design is a standard box truss spacecraft design with a thermal control system, 1.7 m solar arrays for 1 kWe power, a 1 m diameter Ka/S band dish which provides relay communications with the LCT, and a Q-band dish for communications to/from the Earth based assets. While JPL's Team X and Goddard Space Flight Center s (GSFC) I M Design Center (IMDC) have completed two other LRS designs, this NASA Glenn Research Center (GRC) COMPASS LRS design sits between them in terms of physical size and capabilities.

  17. 49 CFR 236.206 - Battery or power supply with respect to relay; location.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Battery or power supply with respect to relay... to relay; location. The battery or power supply for each signal control relay circuit, where an open... from the relay....

  18. 49 CFR 236.206 - Battery or power supply with respect to relay; location.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Battery or power supply with respect to relay... to relay; location. The battery or power supply for each signal control relay circuit, where an open... from the relay....

  19. 49 CFR 236.206 - Battery or power supply with respect to relay; location.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Battery or power supply with respect to relay... to relay; location. The battery or power supply for each signal control relay circuit, where an open... from the relay....

  20. 49 CFR 236.206 - Battery or power supply with respect to relay; location.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Battery or power supply with respect to relay... to relay; location. The battery or power supply for each signal control relay circuit, where an open... from the relay....

  1. 49 CFR 236.206 - Battery or power supply with respect to relay; location.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Battery or power supply with respect to relay... to relay; location. The battery or power supply for each signal control relay circuit, where an open... from the relay....

  2. Optical deep space communication via relay satellite

    NASA Technical Reports Server (NTRS)

    Gagliardi, R. M.; Vilnrotter, V. A.; Dolinar, S. J., Jr.

    1981-01-01

    The possible use of an optical for high rate data transmission from a deep space vehicle to an Earth-orbiting relay satellite while RF links are envisioned for the relay to Earth link was studied. A preliminary link analysis is presented for initial sizing of optical components and power levels, in terms of achievable data rates and feasible range distances. Modulation formats are restricted to pulsed laser operation, involving bot coded and uncoded schemes. The advantage of an optical link over present RF deep space link capabilities is shown. The problems of acquisition, pointing and tracking with narrow optical beams are presented and discussed. Mathematical models of beam trackers are derived, aiding in the design of such systems for minimizing beam pointing errors. The expected orbital geometry between spacecraft and relay satellite, and its impact on beam pointing dynamics are discussed.

  3. Relays from Mars demonstrate international interplanetary networking

    NASA Astrophysics Data System (ADS)

    2004-08-01

    On 4 August at 14:24 CEST, as Mars Express flew over one of NASA’s Mars exploration rovers, Opportunity, it successfully received data previously collected and stored by the rover. The data, including 15 science images from the rover's nine cameras, were then downlinked to ESA’s European Space Operations Centre in Darmstadt (Germany) and immediately relayed to the Mars Exploration Rovers team based at the Jet Propulsion Laboratory in Pasadena, USA. NASA orbiters Mars Odyssey and Mars Global Surveyor have so far relayed most of the data produced by the rovers since they landed in January. Communication compatibility between Mars Express and the rovers had already been demonstrated in February, although at a low rate that did not convey much data. The 4 August session, at a transmit rate of 42.6 megabits in about six minutes, set a new mark for international networking around another planet. The success of this demonstration is the result of years of groundwork and was made possible because both Mars Express and the Mars rovers use the same communication protocol. This protocol, called Proximity-1, was developed by the international Consultative Committee for Space Data Systems, an international partnership for standardising techniques for handling space data. Mars Express was 1400 kilometres above the Martian surface during the 4 August session with Opportunity, with the goal of a reliable transfer of lots of data. Engineers for both agencies plan to repeat this display of international cooperation today, 10 August, with another set of Opportunity images. “We're delighted how well this has been working, and thankful to have Mars Express in orbit,” said Richard Horttor of NASA's Jet Propulsion Laboratory, Pasadena, California, project manager for NASA's role in Mars Express. JPL engineer Gary Noreen of the Mars Network Office said: “the capabilities that our international teamwork is advancing this month could be important in future exploration of Mars

  4. Impact of relay placement on diversity order in adaptive selective DF relay-assisted FSO communications.

    PubMed

    Boluda-Ruiz, Rubén; García-Zambrana, Antonio; Castillo-Vázquez, Beatriz; Castillo-Vázquez, Carmen

    2015-02-09

    The impact of relay placement on diversity order in adaptive selective decode-and-forward (DF) cooperative strategies is here investigated in the context of free-space optical (FSO) communications over atmospheric turbulence channels with pointing errors when line of sight is available. The irradiance of the transmitted optical beam here considered is susceptible to moderate-to-strong turbulence conditions, following a gamma-gamma (GG) distribution together with a misalignment fading model where the effect of beam width, detector size and jitter variance is considered. Novel closed-form approximate bit error-rate (BER) expressions are obtained for a cooperative FSO communication setup with N relays, assuming that these relays are located in an area similar to an annulus around source or destination node. An analytical expression is here found that determines the best selection criterion based on the knowledge of the channel state information (CSI) of source-relay or relay-destination links in order to significantly increase the diversity order corresponding to the cooperative strategy under study. It is concluded that the highest diversity order is achieved when the relation β(SR(min)) > β(SD) + β(R(min)D) is satisfied, wherein β(SR(min)), β(R(min)D) and β(SD) are parameters corresponding to the atmospheric turbulence conditions of source-relay and relay-destination link with the greatest scintillation index, and source-destination link, respectively.

  5. Multiantenna relay beamforming design for QoS discrimination in two-way relay networks.

    PubMed

    Xiong, Ke; Zhang, Yu; Li, Dandan; Chang, Chih-Yung; Zhong, Zhangdui

    2013-01-01

    This paper investigates the relay beamforming design for quality of service (QoS) discrimination in two-way relay networks. The purpose is to keep legitimate two-way relay users exchange their information via a helping multiantenna relay with QoS guarantee while avoiding the exchanged information overhearing by unauthorized receiver. To this end, we propose a physical layer method, where the relay beamforming is jointly designed with artificial noise (AN) which is used to interfere in the unauthorized user's reception. We formulate the joint beamforming and AN (BFA) design into an optimization problem such that the received signal-to-interference-ratio (SINR) at the two legitimate users is over a predefined QoS threshold while limiting the received SINR at the unauthorized user which is under a certain secure threshold. The objective of the optimization problem is to seek the optimal AN and beamforming vectors to minimize the total power consumed by the relay node. Since the optimization problem is nonconvex, we solve it by using semidefinite program (SDP) relaxation. For comparison, we also study the optimal relay beamforming without using AN (BFO) under the same QoS discrimination constraints. Simulation results show that both the proposed BFA and BFO can achieve the QoS discrimination of the two-way transmission. However, the proposed BFA yields significant power savings and lower infeasible rates compared with the BFO method.

  6. Relay communications strategies for Mars exploration through 2020

    NASA Technical Reports Server (NTRS)

    Edwards, Charles D., Jr.; Arnold, B.; DePaula, R.; Kazz, G.; Lee, C.; Noreen, G.

    2005-01-01

    In this paper we will examine NASA's strategy for relay communications support of missions planned for this decade, and discuss options for longer-term relay network evolution in support of second-decade missions.

  7. Deep space optical communication via relay satellite

    NASA Technical Reports Server (NTRS)

    Dolinar, S.; Vilnrotter, V.; Gagliardi, R.

    1981-01-01

    The application of optical communications for a deep space link via an earth-orbiting relay satellite is discussed. The system uses optical frequencies for the free-space channel and RF links for atmospheric transmission. The relay satellite is in geostationary orbit and contains the optics necessary for data processing and formatting. It returns the data to earth through the RF terrestrial link and also transmits an optical beacon to the satellite for spacecraft return pointing and for the alignment of the transmitting optics. Future work will turn to modulation and coding, pointing and tracking, and optical-RF interfacing.

  8. Counterfactual quantum cryptography network with untrusted relay

    NASA Astrophysics Data System (ADS)

    Chen, Yuanyuan; Gu, Xuemei; Jiang, Dong; Xie, Ling; Chen, Lijun

    2015-07-01

    Counterfactual quantum cryptography allows two remote parties to share a secret key even though a physical particle is not in fact transmitted through the quantum channel. In order to extend the scope of counterfactual quantum cryptography, we use an untrusted relay to construct a multi-user network. The implementation issues are discussed to show that the scheme can be realized with current technologies. We also prove the practical security advantages of the scheme by eliminating the probability that an eavesdropper can directly access the signal or an untrusted relay can perform false operations.

  9. Tracking and Data Relay Satellite System (TDRSS)

    NASA Technical Reports Server (NTRS)

    Mckenzie, J.; Vanek, C.

    1991-01-01

    The DSN (Deep Space Network) mission support requirements for the Tracking and Data Relay Satellite System (TDRSS) are summarized. The TDRSS consists of four identical satellites in geosynchronous orbits (35,800 km) and a dedicated ground station. The payload of each satellite is a telecommunications service system that relays communication signals between low earth-orbiting user spacecraft and the TDRSS ground terminal. Mission objectives are outlined and the DSN support requirements are defined through the presentation of tables and narratives describing the spacecraft flight profile; DSN support coverage; frequency assignments; support parameters for telemetry, command and support systems; and tracking support responsibility.

  10. Advanced Strategic and Tactical Relay Request Management for the Mars Relay Operations Service

    NASA Technical Reports Server (NTRS)

    Allard, Daniel A.; Wallick, Michael N.; Gladden, Roy E.; Wang, Paul; Hy, Franklin H.

    2013-01-01

    This software provides a new set of capabilities for the Mars Relay Operations Service (MaROS) in support of Strategic and Tactical relay, including a highly interactive relay request Web user interface, mission control over relay planning time periods, and mission management of allowed strategic vs. tactical request parameters. Together, these new capabilities expand the scope of the system to include all elements critical for Tactical relay operations. Planning of replay activities spans a time period that is split into two distinct phases. The first phase is called Strategic, which begins at the time that relay opportunities are identified, and concludes at the point that the orbiter generates the flight sequences for on board execution. Any relay request changes from this point on are called Tactical. Tactical requests, otherwise called Orbit - er Relay State Changes (ORSC), are highly restricted in terms of what types of changes can be made, and the types of parameters that can be changed may differ from one orbiter to the next. For example, one orbiter may be able to delay the start of a relay request, while another may not. The legacy approach to ORSC management involves exchanges of e-mail with "requests for change" and "acknowledgement of approval," with no other tracking of changes outside of e-mail folders. MaROS Phases 1 and 2 provided the infrastructure for strategic relay for all supported missions. This new version, 3.0, introduces several capabilities that fully expand the scope of the system to include tactical relay. One new feature allows orbiter users to manage and "lock" Planning Periods, which allows the orbiter team to formalize the changeover from Strategic to Tactical operations. Another major feature allows users to interactively submit tactical request changes via a Web user interface. A third new feature allows orbiter missions to specify allowed tactical updates, which are automatically incorporated into the tactical change process

  11. 47 CFR 11.20 - State Relay Network.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false State Relay Network. 11.20 Section 11.20 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL EMERGENCY ALERT SYSTEM (EAS) General § 11.20 State Relay Network. This network is composed of State Relay (SR) sources, leased common carrier...

  12. 47 CFR 90.245 - Fixed relay stations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Fixed relay stations. 90.245 Section 90.245... MOBILE RADIO SERVICES Non-Voice and Other Specialized Operations § 90.245 Fixed relay stations. Except where specifically provided for, fixed relay stations shall be authorized to operate only on...

  13. 47 CFR 11.20 - State Relay Network.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 1 2011-10-01 2011-10-01 false State Relay Network. 11.20 Section 11.20 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL EMERGENCY ALERT SYSTEM (EAS) General § 11.20 State Relay Network. This network is composed of State Relay (SR) sources, leased common carrier...

  14. 49 CFR 234.265 - Timing relays and timing devices.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Timing relays and timing devices. 234.265 Section... Maintenance, Inspection, and Testing Inspections and Tests § 234.265 Timing relays and timing devices. Each timing relay and timing device shall be tested at least once every twelve months. The timing shall...

  15. 47 CFR 90.243 - Mobile relay stations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false Mobile relay stations. 90.243 Section 90.243... MOBILE RADIO SERVICES Non-Voice and Other Specialized Operations § 90.243 Mobile relay stations. (a) Mobile relay operations will be authorized on frequencies below 512 MHz, except in the...

  16. 49 CFR 236.556 - Adjustment of relay.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Adjustment of relay. 236.556 Section 236.556..., Train Control and Cab Signal Systems Rules and Instructions; Locomotives § 236.556 Adjustment of relay. Change in adjustment of relay shall be made only in a shop equipped for that purpose except when...

  17. 47 CFR 90.243 - Mobile relay stations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 5 2011-10-01 2011-10-01 false Mobile relay stations. 90.243 Section 90.243... MOBILE RADIO SERVICES Non-Voice and Other Specialized Operations § 90.243 Mobile relay stations. (a) Mobile relay operations will be authorized on frequencies below 512 MHz, except in the...

  18. 47 CFR 90.245 - Fixed relay stations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false Fixed relay stations. 90.245 Section 90.245... MOBILE RADIO SERVICES Non-Voice and Other Specialized Operations § 90.245 Fixed relay stations. Except where specifically provided for, fixed relay stations shall be authorized to operate only on...

  19. 47 CFR 90.245 - Fixed relay stations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false Fixed relay stations. 90.245 Section 90.245... MOBILE RADIO SERVICES Non-Voice and Other Specialized Operations § 90.245 Fixed relay stations. Except where specifically provided for, fixed relay stations shall be authorized to operate only on...

  20. 47 CFR 11.20 - State Relay Network.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false State Relay Network. 11.20 Section 11.20 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL EMERGENCY ALERT SYSTEM (EAS) General § 11.20 State Relay Network. This network is composed of State Relay (SR) sources, leased common carrier...

  1. 47 CFR 90.243 - Mobile relay stations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Mobile relay stations. 90.243 Section 90.243... MOBILE RADIO SERVICES Non-Voice and Other Specialized Operations § 90.243 Mobile relay stations. (a) Mobile relay operations will be authorized on frequencies below 512 MHz, except in the...

  2. 76 FR 58412 - Relay Services for Deaf-Blind Individuals

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-21

    ... COMMISSION 47 CFR Part 64 Relay Services for Deaf-Blind Individuals AGENCY: Federal Communications Commission... Communications and Video Accessibility Act of 2010, Section 105, Relay Services for Deaf-Blind Individuals...-First Century Communications and Video Accessibility Act of 2010, Section 105, Relay Services for...

  3. 47 CFR 11.20 - State Relay Network.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false State Relay Network. 11.20 Section 11.20 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL EMERGENCY ALERT SYSTEM (EAS) General § 11.20 State Relay Network. This network is composed of State Relay (SR) sources, leased common carrier...

  4. 76 FR 18490 - Contributions to the Telecommunications Relay Service Fund

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-04

    ... COMMISSION 47 CFR Parts 1 and 64 Contributions to the Telecommunications Relay Service Fund AGENCY: Federal...- interconnected VoIP service to participate in and contribute to the Telecommunications Relay Services (TRS) Fund... summary of the Commission's Contributions to the Telecommunications Relay Service Fund, Notice of...

  5. 47 CFR 11.20 - State Relay Network.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false State Relay Network. 11.20 Section 11.20 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL EMERGENCY ALERT SYSTEM (EAS) General § 11.20 State Relay Network. This network is composed of State Relay (SR) sources, leased common carrier...

  6. 49 CFR 236.556 - Adjustment of relay.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Adjustment of relay. 236.556 Section 236.556..., Train Control and Cab Signal Systems Rules and Instructions; Locomotives § 236.556 Adjustment of relay. Change in adjustment of relay shall be made only in a shop equipped for that purpose except when...

  7. 49 CFR 236.556 - Adjustment of relay.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Adjustment of relay. 236.556 Section 236.556..., Train Control and Cab Signal Systems Rules and Instructions; Locomotives § 236.556 Adjustment of relay. Change in adjustment of relay shall be made only in a shop equipped for that purpose except when...

  8. 47 CFR 90.245 - Fixed relay stations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 5 2012-10-01 2012-10-01 false Fixed relay stations. 90.245 Section 90.245... MOBILE RADIO SERVICES Non-Voice and Other Specialized Operations § 90.245 Fixed relay stations. Except where specifically provided for, fixed relay stations shall be authorized to operate only on...

  9. 47 CFR 90.243 - Mobile relay stations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false Mobile relay stations. 90.243 Section 90.243... MOBILE RADIO SERVICES Non-Voice and Other Specialized Operations § 90.243 Mobile relay stations. (a) Mobile relay operations will be authorized on frequencies below 512 MHz, except in the...

  10. 76 FR 65965 - Contributions to the Telecommunications Relay Services Fund

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-25

    ... COMMISSION 47 CFR Parts 1 and 64 Contributions to the Telecommunications Relay Services Fund AGENCY: Federal... contributing to the interstate Telecommunications Relay Services (TRS) Fund in a manner prescribed by... to the Telecommunications Relay Service Fund, Report and Order (Order), document FCC 11-150,...

  11. 77 FR 20553 - Relay Services for Deaf-Blind Individuals

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-05

    ... COMMISSION 47 CFR Part 64 Relay Services for Deaf-Blind Individuals AGENCY: Federal Communications Commission... Relay Services for Deaf-Blind Individuals, Report and Order, document FCC 11-56, published at 76 FR... Commission to allocate up to $10 million annually from the Interstate Telecommunications Relay Services...

  12. 47 CFR 90.243 - Mobile relay stations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 5 2012-10-01 2012-10-01 false Mobile relay stations. 90.243 Section 90.243... MOBILE RADIO SERVICES Non-Voice and Other Specialized Operations § 90.243 Mobile relay stations. (a) Mobile relay operations will be authorized on frequencies below 512 MHz, except in the...

  13. 49 CFR 236.556 - Adjustment of relay.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Adjustment of relay. 236.556 Section 236.556..., Train Control and Cab Signal Systems Rules and Instructions; Locomotives § 236.556 Adjustment of relay. Change in adjustment of relay shall be made only in a shop equipped for that purpose except when...

  14. 49 CFR 234.265 - Timing relays and timing devices.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Timing relays and timing devices. 234.265 Section... Maintenance, Inspection, and Testing Inspections and Tests § 234.265 Timing relays and timing devices. Each timing relay and timing device shall be tested at least once every twelve months. The timing shall...

  15. 47 CFR 90.245 - Fixed relay stations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 5 2011-10-01 2011-10-01 false Fixed relay stations. 90.245 Section 90.245... MOBILE RADIO SERVICES Non-Voice and Other Specialized Operations § 90.245 Fixed relay stations. Except where specifically provided for, fixed relay stations shall be authorized to operate only on...

  16. 49 CFR 236.556 - Adjustment of relay.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Adjustment of relay. 236.556 Section 236.556..., Train Control and Cab Signal Systems Rules and Instructions; Locomotives § 236.556 Adjustment of relay. Change in adjustment of relay shall be made only in a shop equipped for that purpose except when...

  17. Cable Television Service; Cable Television Relay Service.

    ERIC Educational Resources Information Center

    Federal Register, 1972

    1972-01-01

    The rules and regulations of the Federal Communications Commission (FCC) concerning cable television service and cable relay service are presented along with the comments of the National Cable Television Association, the National Association of Broadcasters, the Association of Maximum Service Telecasters, and a major group of program suppliers.…

  18. Relay cross metathesis reactions of vinylphosphonates.

    PubMed

    Malla, Raj K; Ridenour, Jeremy N; Spilling, Christopher D

    2014-01-01

    Dimethyl (β-substituted) vinylphosphonates do not readily undergo cross metathesis reactions with Grubbs catalyst and terminal alkenes. However, the corresponding mono- or diallyl vinylphosphonate esters undergo facile cross metathesis reactions. The improved reactivity is attributed to a relay step in the cross metathesis reaction mechanism.

  19. First Things First: Internet Relay Chat Openings.

    ERIC Educational Resources Information Center

    Rintel, E. Sean; Mulholland, Joan; Pittam, Jeffery

    2001-01-01

    Argues that Internet Relay Chat (IRC) research needs to systematically address links between interaction structures, technological mediation and the instantiation and development of interpersonal relationships. Finds that openings that occur directly following user's entries into public IRC channels are often ambiguous, can disrupt relationship…

  20. Using a micromachined magnetostatic relay in commutating a DC motor

    NASA Technical Reports Server (NTRS)

    Tai, Yu-Chong (Inventor); Wright, John A. (Inventor); Lilienthal, Gerald (Inventor)

    2004-01-01

    A DC motor is commutated by rotating a magnetic rotor to induce a magnetic field in at least one magnetostatic relay in the motor. Each relay is activated in response to the magnetic field to deliver power to at least one corresponding winding connected to the relay. In some cases, each relay delivers power first through a corresponding primary winding and then through a corresponding secondary winding to a common node. Specific examples include a four-pole, three-phase motor in which each relay is activated four times during one rotation of the magnetic rotor.

  1. Optimised secure transmission through untrusted AF relays using link adaptation

    NASA Astrophysics Data System (ADS)

    Taki, Mehrdad; Sadeghi, Mohammad

    2016-05-01

    A new transmission scheme is presented for a two-hop relay network including two AF relays, considering physical layer security where relays are not able to detect signal with an acceptable bit error rate (BER) but the combined received signal is detected with an acceptable BER at the final receiver. It is assumed that there is no direct path between the transmitter and the receiver (relay network without diversity). Adaptive modulation and coding is utilised at the transmitter and transmission powers of the transmitter and of the relays are continuously adapted provisioning individual average power constraint for each node. Numerical evaluations show that an acceptable performance degradation is seen by the proposed secure relaying scheme compared to the optimum relay selection scheme without security constraint.

  2. [Arranging first aid as voluntary work in Jukola-relay].

    PubMed

    Karhumäki, Lauri; Lommi, Marja-Liisa; Mononen, Sanna; Sippo-Tujunen, Inkeri; Lommi, Jyri

    2013-01-01

    Various aspects must be anticipated in the planning of first aid in the massive orienteering contest Jukola-relay. Spreading of the event to a wide forest terrain area, beyond the reach of roads, poses a challenge for the evacuation of injured persons. The communication chains must be secured. In addition to the competition center, first aid points must be devised at various off-road points. Capable volunteers must be recruited in sufficient numbers. Establishing a temporary, health center standard emergency preparedness for approximately 50 000 people necessitates the acquisition of equipment and medicines for emergency care. Preparations must be made for the treatment of injuries and attacks of illness among the competitors, the audience and the volunteers.

  3. Data-Mining-Based Intelligent Differential Relaying for Transmission Lines Including UPFC and Wind Farms.

    PubMed

    Jena, Manas Kumar; Samantaray, Subhransu Ranjan

    2016-01-01

    This paper presents a data-mining-based intelligent differential relaying scheme for transmission lines, including flexible ac transmission system device, such as unified power flow controller (UPFC) and wind farms. Initially, the current and voltage signals are processed through extended Kalman filter phasor measurement unit for phasor estimation, and 21 potential features are computed at both ends of the line. Once the features are extracted at both ends, the corresponding differential features are derived. These differential features are fed to a data-mining model known as decision tree (DT) to provide the final relaying decision. The proposed technique has been extensively tested for single-circuit transmission line, including UPFC and wind farms with in-feed, double-circuit line with UPFC on one line and wind farm as one of the substations with wide variations in operating parameters. The test results obtained from simulation as well as in real-time digital simulator testing indicate that the DT-based intelligent differential relaying scheme is highly reliable and accurate with a response time of 2.25 cycles from the fault inception.

  4. Relay for Life as a Storytelling Occasion: Building Community in the Midst of Suffering.

    PubMed

    Rizzo Weller, Melissa

    2017-02-03

    In this essay, I reflect on my experiences with Relay for Life (RFL), the American Cancer Society's walking event focused on raising awareness and donations for research and patient support programs. I share stories of relationships built within this context and how those relationships are fostered by storytelling. I also draw on literature that brings to light the neoliberal effects of fundraising for health-related causes. In spite of the consumerism that is inherent in fundraising events such as RFL, those of us affected by cancer benefit from the connections created and nurtured in those spaces. We turn to similarly situated others and share stories that unite us into one community. These stories serve as powerful sources of support, healing, and strength. We relay. We story. We build community.

  5. Spaceborne centrifugal relays for spacecraft propulsion

    NASA Technical Reports Server (NTRS)

    Ouzidane, Malika

    1991-01-01

    Acceleration using centrifugal relays is a recently discovered method for the acceleration of spaceborne payloads to high velocity at high thrust. Centrifugal relays are moving rotors which progressively accelerate reaction mass to higher velocities. One important engineering problem consists of accurately tracking the position of the projectiles and rotors and guiding each projectile exactly onto the appropriate guide tracks on each rotor. The topics of this research are the system kinematics and dynamics and the computerized guidance system which will allow the projectile to approach each rotor with exact timing with respect to the rotor rotation period and with very small errors in lateral positions. Kinematics studies include analysis of rotor and projectile positions versus time and projectile/rotor interactions. Guidance studies include a detailed description of the tracking mechanism (interrupt of optical beams) and the aiming mechanism (electromagnetic focusing) including the design of electromagnetic deflection coils and the switching circuitry.

  6. Relay Support for the Mars Science Laboratory and the Coming Decade of Mars Relay Network Evolution

    NASA Technical Reports Server (NTRS)

    Edwards, Charles D., Jr.; Arnold, Bradford W.; Bell, David J.; Bruvold, Kristoffer N.; Gladden, Roy E.; Ilott, Peter A.; Lee, Charles H.

    2012-01-01

    In the past decade, an evolving network of Mars relay orbiters has provided telecommunication relay services to the Mars Exploration Rovers, Spirit and Opportunity, and to the Mars Phoenix Lander, enabling high-bandwidth, energy-efficient data transfer and greatly increasing the volume of science data that can be returned from the Martian surface, compared to conventional direct-to-Earth links. The current relay network, consisting of NASA's Odyssey and Mars Reconnaissance Orbiter and augmented by ESA's Mars Express Orbiter, stands ready to support the Mars Science Laboratory, scheduled to arrive at Mars on Aug 6, 2012, with new capabilities enabled by the Electra and Electra-Lite transceivers carried by MRO and MSL, respectively. The MAVEN orbiter, planned for launch in 2013, and the ExoMars/Trace Gas Orbiter, planned for launch in 2016, will replenish the on-orbit relay network as the current orbiter approach their end of life. Currently planned support scenarios for this future relay network include an ESA EDL Demonstrator Module deployed by the 2016 ExoMars/TGO orbiter, and the 2018 NASA/ESA Joint Rover, representing the first step in a multimission Mars Sample Return campaign.

  7. Non-latching relay switch assembly

    DOEpatents

    Duimstra, Frederick A.

    1991-01-01

    A non-latching relay switch assembly which includes a coil section and a switch or contact section. The coil section includes a permanent magnet and an electromagnet. The respective sections are arranged in separate locations or cavities in the assembly. The switch has a "normal" position and is selectively switched by an overriding electromagnetic assembly. The switch returns to the "normal" position when the overriding electromagnetic assembly is inactive.

  8. Overview of optical data relay system in JAXA

    NASA Astrophysics Data System (ADS)

    Chishiki, Y.; Yamakawa, S.; Takano, Y.; Miyamoto, Y.; Araki, T.; Kohata, H.

    2016-03-01

    To meet increasing demands of high-speed data transmission, JAXA has started to develop a new optical data relay system. This system provides 1.8Gbit/s data relay service through optical inter-satellite link and Ka-band feeder link using JDRS, a data relay satellite. The first user satellite is the Advanced Optical Satellite, a Japanese optical observation satellite in low earth orbit. As a total data relay system, the data relay satellite, Ka-band ground stations and two optical terminals for JDRS and the Advanced Optical Satellite are developed together. Target launch year of JDRS is 2019 in Japanese fiscal year. This paper describes the development plan and technologies of the optical data relay system.

  9. Laser Communications Relay Demonstration (LCRD) Update and the Path Towards Optical Relay Operations

    NASA Technical Reports Server (NTRS)

    Israel, David J.; Edwards, Bernard L.; Staren, John W.

    2017-01-01

    This Presentation provides a concept for an evolution of NASAs optical communications near Earth relay architecture. NASA's Laser Communications Relay Demonstration (LCRD), a joint project between NASAs Goddard Space Flight Center (GSFC), the Jet Propulsion Laboratory - California Institute of Technology (JPL), and the Massachusetts Institute of Technology Lincoln Laboratory (MIT LL). LCRD will provide a minimum of two years of high data rate optical communications service experiments in geosynchronous orbit (GEO), following launch in 2019. This paper will provide an update of the LCRD mission status and planned capabilities and experiments, followed by a discussion of the path from LCRD to operational network capabilities.

  10. Laser Communications Relay Demonstration (LCRD) Update and the Path Towards Optical Relay Operations

    NASA Technical Reports Server (NTRS)

    Israel, David J.; Edwards, Bernard L.; Staren, John W.

    2017-01-01

    This paper provides a concept for an evolution of NASA's optical communications near Earth relay architecture. NASA's Laser Communications Relay Demonstration (LCRD), a joint project between NASA's Goddard Space Flight Center (GSFC), the Jet Propulsion Laboratory - California Institute of Technology (JPL), and the Massachusetts Institute of Technology Lincoln Laboratory (MIT LL). LCRD will provide a minimum of two years of high data rate optical communications service experiments in geosynchronous orbit (GEO), following launch in 2019. This paper will provide an update of the LCRD mission status and planned capabilities and experiments, followed by a discussion of the path from LCRD to operational network capabilities.

  11. Compatibility Study of Protective Relaying in a Grid-Connected Fuel Cell

    SciTech Connect

    Staunton, R.H.

    2004-04-15

    A 200-kW fuel cell produced by International Fuel Cells (IFC), a United Technologies Company, began operation at the National Transportation Research Center (NTRC) in early June 2003. The NTRC is a joint Oak Ridge National laboratory (ORNL) and University of Tennessee research facility located in Knoxville, Tennessee. This research activity investigated the protective relaying functions of this fully commercialized fuel cell power plant, which uses ''synthesized'' protective relays. The project's goal is to characterize the compatibility between the fuel cell's interconnection protection system and the local distribution system or electric power system (EPS). ORNL, with assistance from the Electric Power Research Institute-Power Electronics Applications Center (EPRI-PEAC) in Knoxville, Tennessee, monitored and characterized the system compatibility over a period of 6 months. Distribution utility engineers are distrustful of or simply uncomfortable with the protective relaying and hardware provided as part of distributed generation (DG) plants. Part of this mistrust is due to the fact that utilities generally rely on hardware from certain manufacturers whose reliability is well established based on performance over many years or even decades. Another source of concern is the fact that fuel cells and other types of DG do not use conventional relays but, instead, the protective functions of conventional relays are simulated by digital circuits in the distributed generator's grid interface control unit. Furthermore, the testing and validation of internal protection circuits of DG are difficult to accomplish and can be changed by the vendor at any time. This study investigated and documented the safety and protective relaying present in the IFC fuel cell, collected data on the operation of the fuel cell, recorded event data during EPS disturbances, and assessed the compatibility of the synthesized protective circuits and the local distribution system. The project also

  12. Improving control performance across AWGN channels using a relay node†

    NASA Astrophysics Data System (ADS)

    Kumar, Utsaw; Liu, Jie; Gupta, Vijay; Laneman, J. Nicholas

    2014-07-01

    Consider an unstable linear time-invariant system in which the sensor transmits information to a controller across an additive white Gaussian noise channel. The designer can optionally utilise a relay node to assist the controller; however, the total transmission power consumed by the sensor and the relay node is constant. We consider two topologies: (1) a Gaussian relay channel and (2) a cascade of two Gaussian point-to-point channels. We propose coding schemes and present sufficient conditions for the stabilisability of the plant through such schemes. The analysis suggests that it is useful to utilise a relay node, even if the total transmission power remains the same.

  13. Modified Dynamic Decode-and-Forward Relaying Protocol for Type II Relay in LTE-Advanced and Beyond.

    PubMed

    Nam, Sung Sik; Alouini, Mohamed-Slim; Choi, Seyeong

    2016-01-01

    In this paper, we propose a modified dynamic decode-and-forward (MoDDF) relaying protocol to meet the critical requirements for user equipment (UE) relays in next-generation cellular systems (e.g., LTE-Advanced and beyond). The proposed MoDDF realizes the fast jump-in relaying and the sequential decoding with an application of random codeset to encoding and re-encoding process at the source and the multiple UE relays, respectively. A subframe-by-subframe decoding based on the accumulated (or buffered) messages is employed to achieve energy, information, or mixed combining. Finally, possible early termination of decoding at the end user can lead to the higher spectral efficiency and more energy saving by reducing the frequency of redundant subframe transmission and decoding. These attractive features eliminate the need of directly exchanging control messages between multiple UE relays and the end user, which is an important prerequisite for the practical UE relay deployment.

  14. Three phase AC motor controller

    DOEpatents

    Vuckovich, Michael; Wright, Maynard K.; Burkett, John P.

    1984-03-20

    A motor controller for a three phase AC motor (10) which is adapted to operate bidirectionally from signals received either from a computer (30) or a manual control (32). The controller is comprised of digital logic circuit means which implement a forward and reverse command signal channel (27, 29) for the application of power through the forward and reverse power switching relays (16, 18, 20, 22). The digital logic elements are cross coupled to prevent activation of both channels simultaneously and each includes a plugging circuit (65, 67) for stopping the motor upon the removal of control signal applied to one of the two channels (27, 29) for a direction of rotation desired. Each plugging circuit (65, 67) includes a one-shot pulse signal generator (88, 102) which outputs a single pulse signal of predetermined pulsewidth which is adapted to inhibit further operation of the application of power in the channel which is being activated and to apply a reversal command signal to the other channel which provides a reversed phase application of power to the motor for a period defined by the pulse-width output of the one-shot signal generator to plug the motor (10) which will then be inoperative until another rotational command signal is applied to either of the two channels.

  15. Sparsity-aware multiple relay selection in large multi-hop decode-and-forward relay networks

    NASA Astrophysics Data System (ADS)

    Gouissem, A.; Hamila, R.; Al-Dhahir, N.; Foufou, S.

    2016-12-01

    In this paper, we propose and investigate two novel techniques to perform multiple relay selection in large multi-hop decode-and-forward relay networks. The two proposed techniques exploit sparse signal recovery theory to select multiple relays using the orthogonal matching pursuit algorithm and outperform state-of-the-art techniques in terms of outage probability and computation complexity. To reduce the amount of collected channel state information (CSI), we propose a limited-feedback scheme where only a limited number of relays feedback their CSI. Furthermore, a detailed performance-complexity tradeoff investigation is conducted for the different studied techniques and verified by Monte Carlo simulations.

  16. 78 FR 40407 - Structure and Practices of the Video Relay Service Program: Telecommunications Relay Services and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-05

    ... Relay Services and Speech-to-Speech Services for Individuals With Hearing and Speech Disabilities AGENCY..., by commercial overnight courier, or by first-class or overnight U.S. Postal Service mail (although... the building. Commercial Mail sent by overnight mail (other than U.S. Postal Service Express Mail...

  17. 76 FR 24442 - Structure and Practices of the Video Relay Service Program; Telecommunications Relay Services and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-02

    ... Relay Services and Speech-to-Speech Services for Individuals With Hearing and Speech Disabilities AGENCY... or messenger delivery, by commercial overnight courier, or by first-class or overnight U.S. Postal... before entering the building. Commercial Mail sent by overnight mail (other than U.S. Postal...

  18. 49 CFR 236.737 - Cut-section, relayed.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Cut-section, relayed. 236.737 Section 236.737..., MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.737 Cut-section, relayed. A cut-section where the energy for one track circuit is supplied through front...

  19. 49 CFR 236.737 - Cut-section, relayed.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Cut-section, relayed. 236.737 Section 236.737..., MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.737 Cut-section, relayed. A cut-section where the energy for one track circuit is supplied through front...

  20. Implementation of a Relay Coordination System for the Mars Network

    NASA Technical Reports Server (NTRS)

    Allard, Daniel A.

    2010-01-01

    Mars network relay operations involve the coordination of lander and orbiter teams through long-term and short-term planning, tactical changes and post-pass analysis. Much of this coordination is managed through email traffic and point-to-point file data exchanges. It is often difficult to construct a complete and accurate picture of the relay situation at any given moment, as there is no centralized store of correlated relay data. The Mars Relay Operations Service (MaROS) is being implemented to address the problem of relay coordination for current and next-generation relay missions. The service is provided for the purpose of coordinating communications sessions between landed spacecraft assets and orbiting spacecraft assets at Mars. The service centralizes a set of functions previously distributed across multiple spacecraft operations teams, and as such greatly improves visibility into the end-to-end strategic coordination process. Most of the process revolves around the scheduling of communications sessions between the spacecraft during periods of time when a landed asset on Mars is geometrically visible by an orbiting spacecraft. These "relay" sessions are used to transfer data both to and from the landed asset via the orbiting asset on behalf of Earth-based spacecraft operators. This paper will discuss the relay coordination problem space, overview the architecture and design selected to meet system requirements, and describe the first phase of system implementation

  1. Progressively Communicating Rich Telemetry from Autonomous Underwater Vehicles via Relays

    DTIC Science & Technology

    2012-06-01

    2012-10 DOCTORAL DISSERTATION by Chris Murphy June 2012 Progressively Communicating Rich Telemetry from Autonomous Underwater Vehicles via Relays MIT...MIT/WHO I 2012-10 Progressively Communicating Rich Telemetry from Autonomous Underwater Vehicles via Relays by Chris Murphy Massachusetts...States Government. This thesis should be cited as: Chris Murphy, 2012. Progressively Communicating Rich Telemetry from Autonomous Underwater Vehicles

  2. MaROS Strategic Relay Planning and Coordination Interfaces

    NASA Technical Reports Server (NTRS)

    Allard, Daniel A.

    2010-01-01

    The Mars Relay Operations Service (MaROS) is designed to provide planning and analysis tools in support of ongoing Mars Network relay operations. Strategic relay planning requires coordination between lander and orbiter mission ground data system (GDS) teams to schedule and execute relay communications passes. MaROS centralizes this process, correlating all data relevant to relay coordination to provide a cohesive picture of the relay state. Service users interact with the system through thin-layer command line and web user interface client applications. Users provide and utilize data such as lander view periods of orbiters, Deep Space Network (DSN) antenna tracks, and reports of relay pass performance. Users upload and download relevant relay data via formally defined and documented file structures including some described in Extensible Markup Language (XML). Clients interface with the system via an http-based Representational State Transfer (ReST) pattern using Javascript Object Notation (JSON) formats. This paper will provide a general overview of the service architecture and detail the software interfaces and considerations for interface design.

  3. Using the 5 P Relay in Task Groups

    ERIC Educational Resources Information Center

    Stanley, Paula Helen

    2006-01-01

    This article describes the 5 P Relay, a group exercise that can increase the effectiveness of task groups. The 5 P Relay is based on the principles and concepts of the Invitational Model, which emphasizes the importance of assessing the effectiveness or health of five aspects of an organization's environment: people, places, programs, processes,…

  4. 77 FR 1039 - Internet-Based Telecommunications Relay Service Numbering

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-09

    ... COMMISSION 47 CFR Part 64 Internet-Based Telecommunications Relay Service Numbering AGENCY: Federal... rules that govern access to toll-free numbers by users of Internet- based Telecommunications Relay... an impact on any rules of particular applicability. Subject: Internet-Based Telecommunications...

  5. 77 FR 42187 - Relay Services for Deaf-Blind Individuals

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-18

    ... COMMISSION 47 CFR Part 64 Relay Services for Deaf-Blind Individuals AGENCY: Federal Communications Commission... Communications and Video Accessibility Act of 2010, Section 105, Relay Services for Deaf-Blind Individuals, Order... the Twenty-first Century Communications and Video Accessibility Act of 2010, Section 105,...

  6. A Geosynchronous Orbit Optical Communications Relay Architecture

    NASA Technical Reports Server (NTRS)

    Edwards, Bernard L.; Israel, David J.

    2014-01-01

    NASA is planning to fly a Next Generation Tracking and Data Relay Satellite (TDRS) next decade. While the requirements and architecture for that satellite are unknown at this time, NASA is investing in communications technologies that could be deployed on the satellite to provide new communications services. One of those new technologies is optical communications. The Laser Communications Relay Demonstration (LCRD) project, scheduled for launch in December 2017 as a hosted payload on a commercial communications satellite, is a critical pathfinder towards NASA providing optical communications services on the Next Generation TDRS. While it is obvious that a small to medium sized optical communications terminal could be flown on a GEO satellite to provide support to Near Earth missions, it is also possible to deploy a large terminal on the satellite to support Deep Space missions. Onboard data processing and Delay Tolerant Networking (DTN) are two additional technologies that could be used to optimize optical communications link services and enable additional mission and network operations. This paper provides a possible architecture for the optical communications augmentation of a Next Generation TDRS and touches on the critical technology work currently being done at NASA. It will also describe the impact of clouds on such an architecture and possible mitigation techniques.

  7. An economically viable space power relay system

    NASA Astrophysics Data System (ADS)

    Bekey, Ivan; Boudreault, Richard

    1999-09-01

    This paper describes and analyzes the economics of a power relay system that takes advantage of recent technological advances to implement a system that is economically viable. A series of power relay systems are described and analyzed which transport power ranging from 1,250 megawatts to 5,000 megawatts, and distribute it to receiving sites at transcontinental distances. Two classes of systems are discussed—those with a single reflector and delivering all the power to a single rectenna, and a second type which has multiple reflectors and distributes it to 10 rectenna sites, sharing power among them. It is shown that when offering electricity at prices competitive to those prevalent in developed cities in the US that a low IRR is inevitable, and economic feasibility of a business is unlikely. However, when the target market is Japan where the prevalent electricity prices are much greater, that an IRR exceeding 65% is readily attainable. This is extremely attractive to potential investors, making capitalization of a venture likely. The paper shows that the capital investment required for the system can be less than 1 per installed watt, contributing less than 0.02 /KW-hr to the cost of energy provision. Since selling prices in feasible regions range from 0.18 to over 030 $/kW-hr, these costs are but a small fraction of the operating expenses. Thus a very large IRR is possible for such a business.

  8. Generalizing performance limitations of relay neurons: application to Parkinson's disease.

    PubMed

    Agarwal, Rahul; Santaniello, Sabato; Sarma, Sridevi V

    2014-01-01

    Relay cells are prevalent throughout sensory systems and receive two types of inputs: driving and modulating. The driving input contains receptive field properties that must be transmitted while the modulating input alters the specifics of transmission. Relay reliability of a relay cell is defined as the fraction of pulses in the driving input that generate action potentials at the neuron's output, and is in general a complicated function of the driving input, the modulating input and the cell's properties. In a recent study, we computed analytic bounds on the reliability of relay neurons for a class of Poisson driving inputs and sinusoidal modulating inputs. Here, we generalize our analysis and compute bounds on the relay reliability for any modulating input. Furthermore, we show that if the modulating input is generated by a colored Gaussian process, closed form expressions for bounds on relay reliability can be derived. We applied our analysis to investigate relay reliability of thalamic cells in health and in Parkinson's disease (PD). It is hypothesized that in health, neurons in the motor thalamus relay information only when needed and this capability is compromised in PD due to exaggerated beta-band oscillations in the modulating input from the basal ganglia (BG). To test this hypothesis, we used modulating and driving inputs simulated from a detailed computational model of the cortico-BG-thalamo-cortical motor loop and computed our theoretical bounds in both PD and healthy conditions. Our bounds match well with our empirically computed reliability and show that the relay reliability is larger in the healthy condition across the population of thalamic neurons. Furthermore, we show that the increase in power in the beta-band of the modulating input (output of BG) is causally related with the decrease in relay reliability in the PD condition.

  9. Studies on the Enantioselective Iminium Ion Trapping of Radicals Triggered by an Electron-Relay Mechanism

    PubMed Central

    2017-01-01

    A combination of electrochemical, spectroscopic, computational, and kinetic studies has been used to elucidate the key mechanistic aspects of the previously reported enantioselective iminium ion trapping of photochemically generated carbon-centered radicals. The process, which provides a direct way to forge quaternary stereocenters with high fidelity, relies on the interplay of two distinct catalytic cycles: the aminocatalytic electron-relay system, which triggers the stereoselective radical trap upon iminium ion formation, and the photoredox cycle, which generates radicals under mild conditions. Critical to reaction development was the use of a chiral amine catalyst, bearing a redox-active carbazole unit, which could rapidly reduce the highly reactive and unstable intermediate generated upon radical interception. The carbazole unit, however, is also involved in another step of the electron-relay mechanism: the transiently generated carbazole radical cation acts as an oxidant to return the photocatalyst into the original state. By means of kinetic and spectroscopic studies, we have identified the last redox event as being the turnover-limiting step of the overall process. This mechanistic framework is corroborated by the linear correlation between the reaction rate and the reduction potential of the carbazole unit tethered to the aminocatalyst. The redox properties of the carbazole unit can thus be rationally tuned to improve catalytic activity. This knowledge may open a path for the mechanistically driven design of the next generation of electron-relay catalysts. PMID:28281754

  10. Studies on the Enantioselective Iminium Ion Trapping of Radicals Triggered by an Electron-Relay Mechanism.

    PubMed

    Bahamonde, Ana; Murphy, John J; Savarese, Marika; Brémond, Éric; Cavalli, Andrea; Melchiorre, Paolo

    2017-03-29

    A combination of electrochemical, spectroscopic, computational, and kinetic studies has been used to elucidate the key mechanistic aspects of the previously reported enantioselective iminium ion trapping of photochemically generated carbon-centered radicals. The process, which provides a direct way to forge quaternary stereocenters with high fidelity, relies on the interplay of two distinct catalytic cycles: the aminocatalytic electron-relay system, which triggers the stereoselective radical trap upon iminium ion formation, and the photoredox cycle, which generates radicals under mild conditions. Critical to reaction development was the use of a chiral amine catalyst, bearing a redox-active carbazole unit, which could rapidly reduce the highly reactive and unstable intermediate generated upon radical interception. The carbazole unit, however, is also involved in another step of the electron-relay mechanism: the transiently generated carbazole radical cation acts as an oxidant to return the photocatalyst into the original state. By means of kinetic and spectroscopic studies, we have identified the last redox event as being the turnover-limiting step of the overall process. This mechanistic framework is corroborated by the linear correlation between the reaction rate and the reduction potential of the carbazole unit tethered to the aminocatalyst. The redox properties of the carbazole unit can thus be rationally tuned to improve catalytic activity. This knowledge may open a path for the mechanistically driven design of the next generation of electron-relay catalysts.

  11. Satellite data-relay activities in Arizona

    USGS Publications Warehouse

    Boner, F.C.; Blee, J.W.; Shope, W.G.

    1985-01-01

    The U.S. Geological Survey (USGS) Arizona District collects data from automated streamflow stations for a wide variety of uses. Data from these stations are provided to Federal, State, and local agencies that have a responsibility to issue flood warnings; to generate forecasts of water availability; to monitor flow to insure compliance with treaties and other legal mandates; and to manage reservoirs for hydropower, flood abatement, and municipal and irrigation water supply. In the mid-1970's, the escalation of data collection costs and a need for more timely data led the Arizona District to examine alternatives for remote data acquisition. On the basis of successful data communications experiments with NASA 's Landsat satellite, an operational system for satellite-data relay was developed in 1976 using the National Oceanic and Atmospheric Administrations 's (NOAA) Geostationary Operational Environmental Satellite (GOES). A total of 62 data collection platforms (DCP's) was operated in 1983. Satellite telemetry operations are controlled at the remote data-collection stations by small battery-operated data collection platforms. The DCP 's periodically collect data from the sensors, store the data in computer memory, and at preset times transmit the data to the GOES satellite. The satellite retransmits the data to Earth where a ground-receive station transmits or transfers the data by land communications to the USGS computer in Reston, Virginia, for processing. The satellite relay transfers the data from sensor to computer in minutes; therefore, the data are available to users on a near real-time basis. (Author 's abstract)

  12. Wireless Information Surveillance via Proactive Eavesdropping with Spoofing Relay

    NASA Astrophysics Data System (ADS)

    Zeng, Yong; Zhang, Rui

    2016-12-01

    Wireless information surveillance, by which suspicious wireless communications are closely monitored by legitimate agencies, is an integral part of national security. To enhance the information surveillance capability, we propose in this paper a new proactive eavesdropping approach via a spoofing relay, where the legitimate monitor operates in a full-duplex manner with simultaneous eavesdropping and spoofing relaying to vary the source transmission rate in favor of the eavesdropping performance. To this end, a power splitting receiver is proposed, where the signal received at each antenna of the legitimate monitor is split into two parts for information eavesdropping and spoofing relaying, respectively. We formulate an optimization problem to maximize the achievable eavesdropping rate by jointly optimizing the power splitting ratios and relay beamforming matrix at the multi-antenna monitor. Depending on the suspicious and eavesdropping channel conditions, the optimal solution corresponds to three possible spoofing relay strategies, namely \\emph{constructive relaying}, \\emph{jamming}, and \\emph{simultaneous jamming and destructive relaying}. Numerical results show that the proposed technique significantly improves the eavesdropping rate of the legitimate monitor as compared to the existing passive eavesdropping and jamming-based eavesdropping schemes.

  13. Solar Particle Induced Upsets in the TDRS-1 Attitude Control System RAM During the October 1989 Solar Particle Events

    NASA Technical Reports Server (NTRS)

    Croley, D. R.; Garrett, H. B.; Murphy, G. B.; Garrard,T. L.

    1995-01-01

    The three large solar particle events, beginning on October 19, 1989 and lasting approximately six days, were characterized by high fluences of solar protons and heavy ions at 1 AU. During these events, an abnormally large number of upsets (243) were observed in the random access memory of the attitude control system (ACS) control processing electronics (CPE) on-board the geosynchronous TDRS-1 (Telemetry and Data Relay Satellite). The RAM unit affected was composed of eight Fairchild 93L422 memory chips. The Galileo spacecraft, launched on October 18, 1989 (one day prior to the solar particle events) observed the fluxes of heavy ions experienced by TDRS-1. Two solid-state detector telescopes on-board Galileo, designed to measure heavy ion species and energy, were turned on during time periods within each of the three separate events. The heavy ion data have been modeled and the time history of the events reconstructed to estimate heavy ion fluences. These fluences were converted to effective LET spectra after transport through the estimated shielding distribution around the TDRS-1 ACS system. The number of single event upsets (SEU) expected was calculated by integrating the measured cross section for the Fairchild 93L422 memory chip with average effective LET spectrum. The expected number of heavy ion induced SEU's calculated was 176. GOES-7 proton data, observed during the solar particle events, were used to estimate the number of proton-induced SEU's by integrating the proton fluence spectrum incident on the memory chips, with the two-parameter Bendel cross section for proton SEU'S. The proton fluence spectrum at the device level was gotten by transporting the protons through the estimated shielding distribution. The number of calculated proton-induced SEU's was 72, yielding a total of 248 predicted SEU'S, very dose to the 243 observed SEU'S. These calculations uniquely demonstrate the roles that solar heavy ions and protons played in the production of SEU

  14. Electrical and chemical synapses between relay neurons in developing thalamus.

    PubMed

    Lee, Seung-Chan; Cruikshank, Scott J; Connors, Barry W

    2010-07-01

    Gap junction-mediated electrical synapses interconnect diverse types of neurons in the mammalian brain, and they may play important roles in the synchronization and development of neural circuits. Thalamic relay neurons are the major source of input to neocortex. Electrical synapses have not been directly observed between relay neurons in either developing or adult animals. We tested for electrical synapses by recording from pairs of relay neurons in acute slices of developing ventrobasal nucleus (VBN) of the thalamus from rats and mice. Electrical synapses were common between VBN relay neurons during the first postnatal week, and then declined sharply during the second week. Electrical coupling was reduced among cells of connexin36 (Cx36) knockout mice; however, some neuron pairs remained coupled. This implies that electrical synapses between the majority of coupled VBN neurons require Cx36 but that other gap junction proteins also contribute. The anatomical distribution of a beta-galactosidase reporter indicated that Cx36 was expressed in some VBN neurons during the first postnatal week and sharply declined over the second week, consistent with our physiological results. VBN relay neurons also communicated via chemical synapses. Rare pairs of relay neurons excited one another monosynaptically. Much more commonly, spikes in one relay neuron evoked disynaptic inhibition (via the thalamic reticular nucleus) in the same or a neighbouring relay neuron. Disynaptic inhibition between VBN cells emerged as electrical coupling was decreasing, during the second postnatal week. Our results demonstrate that thalamic relay neurons communicate primarily via electrical synapses during early postnatal development, and then lose their electrical coupling as a chemical synapse-mediated inhibitory circuit matures.

  15. From Onions to Shallots: Rewarding Tor Relays with TEARS

    DTIC Science & Technology

    2014-07-18

    From Onions to Shallots: Rewarding Tor Relays with TEARS Rob Jansen1, Andrew Miller2, Paul Syverson1, and Bryan Ford3 1 U.S. Naval Research... Onions to Shallots: Rewarding Tor Relays with TEARS 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e...which, as in BRAIDS [15], may be contained within an onion -wrapped message). Thus, with- out needing to interact with the bank, the relay can confirm the

  16. Lessons Learned from Coordinating Relay Activities at Mars

    NASA Technical Reports Server (NTRS)

    Gladden, Roy E.; Hwang, Pauline; Waggoner, Bruce; McLaughlin, Bruce; Fieseler, Paul; Thomas, Reid; Bigwood, Maria; Herrera, Paul

    2005-01-01

    The Mission Management Office at the Jet Propulsion Laboratory was tasked with coordinating the relay of data between multiple spacecraft at Mars in support of the Mars Exploration Rover Missions in early 2004. The confluence of three orbiters (Mars Global Surveyor, Mars Odyssey, and Mars Express), two rovers (Spirit and Opportunity), and one lander (Beagle 2) has provided a challenging operational scenario that required careful coordination between missions to provide the necessary support and to avoid potential interference during simultaneous relay sessions. As these coordination efforts progressed, several important lessons were learned that should be applied to future Mars relay activities.

  17. A monolithically integrated torsional CMOS-MEMS relay

    NASA Astrophysics Data System (ADS)

    Riverola, M.; Sobreviela, G.; Torres, F.; Uranga, A.; Barniol, N.

    2016-11-01

    We report experimental demonstrations of a torsional microelectromechanical (MEM) relay fabricated using the CMOS-MEMS approach (or intra-CMOS) which exploits the full foundry inherent characteristics enabling drastic reduction of the fabrication costs and batch production. In particular, the relay is monolithically integrated in the back end of line of a commercial standard CMOS technology (AMS 0.35 μm) and released by means of a simple one-step mask-less wet etching. The fabricated torsional relay exhibits an extremely steep switching behaviour symmetrical about both contact sides with an on-state contact resistance in the k Ω -range throughout the on-off cycling test.

  18. 49 CFR 236.109 - Time releases, timing relays and timing devices.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Time releases, timing relays and timing devices... releases, timing relays and timing devices. Time releases, timing relays and timing devices shall be tested... predetermined time interval, which shall be shown on the plans or marked on the time release, timing relay,...

  19. 75 FR 25255 - Structure and Practices of the Video Relay Service Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-07

    ... COMMISSION Structure and Practices of the Video Relay Service Program AGENCY: Federal Communications... of calls made through Video Relay Service (VRS), a form of Telecommunications Relay Service (TRS... purposes of setting VRS compensation rates. The Relay Services Data Request form, which is submitted to...

  20. 49 CFR 236.109 - Time releases, timing relays and timing devices.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Time releases, timing relays and timing devices... releases, timing relays and timing devices. Time releases, timing relays and timing devices shall be tested... predetermined time interval, which shall be shown on the plans or marked on the time release, timing relay,...

  1. 49 CFR 236.109 - Time releases, timing relays and timing devices.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Time releases, timing relays and timing devices... releases, timing relays and timing devices. Time releases, timing relays and timing devices shall be tested... predetermined time interval, which shall be shown on the plans or marked on the time release, timing relay,...

  2. 49 CFR 236.109 - Time releases, timing relays and timing devices.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Time releases, timing relays and timing devices... releases, timing relays and timing devices. Time releases, timing relays and timing devices shall be tested... predetermined time interval, which shall be shown on the plans or marked on the time release, timing relay,...

  3. 49 CFR 236.109 - Time releases, timing relays and timing devices.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Time releases, timing relays and timing devices... releases, timing relays and timing devices. Time releases, timing relays and timing devices shall be tested... predetermined time interval, which shall be shown on the plans or marked on the time release, timing relay,...

  4. Relationship between exchange block time in swim starts and final performance in relay races in international championships.

    PubMed

    Saavedra, Jose M; García-Hermoso, Antonio; Escalante, Yolanda; Dominguez, Ana M; Arellano, Raul; Navarro, Fernando

    2014-01-01

    The purpose of this study was to investigate the association between relay exchange block time and final performance in 4 × 100-m and 4 × 200-m freestyle and 4 × 100-m medley relays as a function of sex (men and women) and classification (medallists and non-medallists) in international competitions. Nineteen international competitions covering a 13-year period (2000-2012) were analysed retrospectively. The data corresponded to a total of 827 team relay histories (407 men, 420 women). Kruskal-Wallis and Mann-Whitney tests were performed to determine any differences by sex, classification, and event. Similarly, the relationship between the exchange block times and final performance was examined by means of a Pearson correlation analysis. In the three events, the men's exchange block times were shorter than those of the women (η(2) = 0.049-0.109; P < 0.001). The exchange block time was especially relevant for the women's relay medallists in the 4 × 100-m freestyle (r = 0.306, P = 0.021) and 4 × 100-m medley (r = 0.385, P = 0.011), while for men the relationship was clearer for the non-medallists. These results suggest that the exchange block time should be considered as one of the performance parameters of swimming relay starts, and thus should be included explicitly as part of training. In particular, the coach could design training targeted at standardising an optimal exchange block time equal to or less than that expected for other teams in the competition.

  5. ACS: ALMA Common Software

    NASA Astrophysics Data System (ADS)

    Chiozzi, Gianluca; Šekoranja, Matej

    2013-02-01

    ALMA Common Software (ACS) provides a software infrastructure common to all ALMA partners and consists of a documented collection of common patterns and components which implement those patterns. The heart of ACS is based on a distributed Component-Container model, with ACS Components implemented as CORBA objects in any of the supported programming languages. ACS provides common CORBA-based services such as logging, error and alarm management, configuration database and lifecycle management. Although designed for ALMA, ACS can and is being used in other control systems and distributed software projects, since it implements proven design patterns using state of the art, reliable technology. It also allows, through the use of well-known standard constructs and components, that other team members whom are not authors of ACS easily understand the architecture of software modules, making maintenance affordable even on a very large project.

  6. An Ac transposon system based on maize chromosome 4S for isolating long-distance-transposed Ac tags in the maize genome.

    PubMed

    Wang, Fei; Li, Zhaoying; Fan, Jun; Li, Pengfei; Hu, Wei; Wang, Gang; Xu, Zhengkai; Song, Rentao

    2010-12-01

    Transposon tagging is an important tool for gene isolation and functional studies. In maize, several transposon-tagging systems have been developed, mostly using Activator/Dissociation (Ac/Ds) and Mutator systems. Here, we establish another Ac-based transposon system with the donor Ac tightly linked with sugary1 (su1) on maize chromosome 4S. Newly transposed Ac (tr-Acs) were detected based on a negative dosage effect, and long-distance-transposed Ac events were identified and isolated from the donor Ac by a simple backcross scheme. In this study, we identified 208 independent long-distance-transposed Ac lines. Thirty-one flanking sequences of these tr-Acs were isolated and localized in the maize genome. As found in previous studies, the tr-Acs preferentially inserted into genic sequences. The distribution of tr-Acs is not random. In our study, the tr-Acs preferentially transposed into chromosomes 1, 2, 9 and 10. We discuss the preferential distribution of tr-Acs from Ac systems. Our system is complementary to two other Ac-based regional-mutagenesis systems in maize, and the combined use of these systems will achieve an even and high-density distribution of Ac elements throughout the maize genome for functional-genomics studies.

  7. 129. INTERIOR OF RELAY BOX FOR HYDRAULIC CONTROL PANEL IN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    129. INTERIOR OF RELAY BOX FOR HYDRAULIC CONTROL PANEL IN UMBILICAL MAST PUMP ROOM (209), LSB (BLDG. 751) - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  8. 111. RELAY BOX AND SWITCHES AT SOUTH END OF HYDRAULIC ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    111. RELAY BOX AND SWITCHES AT SOUTH END OF HYDRAULIC CONTROL PANEL, UMBILICAL MAST PUMP ROOM (109), LSB (BLDG. 770) - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 West, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  9. 20. OBLIQUE VIEW, VANE LINE RELAY, CYLINDRICAL HOUSING, NEW HAVEN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    20. OBLIQUE VIEW, VANE LINE RELAY, CYLINDRICAL HOUSING, NEW HAVEN SIGNAL SHOP - New York, New Haven & Hartford Railroad, Automatic Signalization System, Long Island Sound shoreline between Stamford & New Haven, Stamford, Fairfield County, CT

  10. 34. ELEVATION OF RELAY AND CONTROL SWITCHBOARD, SANTA ANA RIVER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    34. ELEVATION OF RELAY AND CONTROL SWITCHBOARD, SANTA ANA RIVER P.H. #3, JUNE 23, 1943. SCE drawing no. 413187-1. - Santa Ana River Hydroelectric System, SAR-3 Powerhouse, San Bernardino National Forest, Redlands, San Bernardino County, CA

  11. 18. VIEW OF URBAN DISPATCH RELAY ROOM, FIRST FLOOR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. VIEW OF URBAN DISPATCH - RELAY ROOM, FIRST FLOOR (THIS IS THE CONTROL CENTER FOR TRACK SWITCHES) - Pennsylvania Railroad, Harrisburg Station & Trainshed, Market & South Fourth Streets, Harrisburg, Dauphin County, PA

  12. Reliable quantum communication over a quantum relay channel

    SciTech Connect

    Gyongyosi, Laszlo; Imre, Sandor

    2014-12-04

    We show that reliable quantum communication over an unreliable quantum relay channels is possible. The coding scheme combines the results on the superadditivity of quantum channels and the efficient quantum coding approaches.

  13. 130. RELAY SWITCHES AT SOUTH END OF HYDRAULIC CONTROL PANEL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    130. RELAY SWITCHES AT SOUTH END OF HYDRAULIC CONTROL PANEL IN UMBILICAL MAST PUMP ROOM (209), LSB (BLDG. 751) - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  14. 132. INTERIOR OF HYDRAULIC PUMPING UNIT RELAY BOX ON SOUTH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    132. INTERIOR OF HYDRAULIC PUMPING UNIT RELAY BOX ON SOUTH WALL OF CONTROL ROOM (114), LSB (BLDG. 770) - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 West, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  15. 16. FRONT VIEW, MODEL 15 VANE RELAY, NEW HAVEN SIGNAL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. FRONT VIEW, MODEL 15 VANE RELAY, NEW HAVEN SIGNAL SHOP - New York, New Haven & Hartford Railroad, Automatic Signalization System, Long Island Sound shoreline between Stamford & New Haven, Stamford, Fairfield County, CT

  16. 51. Electrical contacts and relays in the south machinery room ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    51. Electrical contacts and relays in the south machinery room (interior of both machinery rooms is identical). Facing south. - Henry Ford Bridge, Spanning Cerritos Channel, Los Angeles-Long Beach Harbor, Los Angeles, Los Angeles County, CA

  17. INTERIOR, FIRST FLOOR, SHOWING BANKS OF ELECTROMECHANICAL RELAYS, CAMERA FACING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR, FIRST FLOOR, SHOWING BANKS OF ELECTRO-MECHANICAL RELAYS, CAMERA FACING SOUTHEAST. - New Haven Rail Yard, Interlocking Control Building, Vicinity of Union Avenue, New Haven, New Haven County, CT

  18. 19. FRONT VIEW, VALVE LINE RELAY, CYLINDRICAL HOUSING, NEW HAVEN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    19. FRONT VIEW, VALVE LINE RELAY, CYLINDRICAL HOUSING, NEW HAVEN SIGNAL SHOP - New York, New Haven & Hartford Railroad, Automatic Signalization System, Long Island Sound shoreline between Stamford & New Haven, Stamford, Fairfield County, CT

  19. 10. INTERIOR DETAIL, FIRST STORY, SHOWING RELAY RACKS Baltimore ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. INTERIOR DETAIL, FIRST STORY, SHOWING RELAY RACKS - Baltimore & Potomac Interlocking Tower, Adjacent to AMTRAK railroad tracks in block bounded by Howard Street, Jones Falls Expressway, Maryland Avenue & Falls Road, Baltimore, Independent City, MD

  20. 17. SIDE VIEW, DETAIL, MODEL 15 VANE RELAY, NEW HAVEN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    17. SIDE VIEW, DETAIL, MODEL 15 VANE RELAY, NEW HAVEN SIGNAL SHOP - New York, New Haven & Hartford Railroad, Automatic Signalization System, Long Island Sound shoreline between Stamford & New Haven, Stamford, Fairfield County, CT

  1. 8. North elevation of electric relay station showing electrical cable ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. North elevation of electric relay station showing electrical cable connection to tower. - New York, New Haven, & Hartford Railroad, Shell Interlocking Tower, New Haven Milepost 16, approximately 100 feel east of New Rochelle Junction, New Rochelle, Westchester County, NY

  2. 18. SIDE VIEW, MODEL 15 VANE RELAY, NEW HAVEN SIGNAL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. SIDE VIEW, MODEL 15 VANE RELAY, NEW HAVEN SIGNAL SHOP - New York, New Haven & Hartford Railroad, Automatic Signalization System, Long Island Sound shoreline between Stamford & New Haven, Stamford, Fairfield County, CT

  3. 76 FR 31261 - Relay Services for Deaf-Blind Individuals

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-31

    ... From the Federal Register Online via the Government Publishing Office ] FEDERAL COMMUNICATIONS COMMISSION 47 CFR Part 64 Relay Services for Deaf-Blind Individuals AGENCY: Federal Communications Commission. ACTION: Final rule; correction. SUMMARY: The Federal Communications Commission (FCC) is correcting...

  4. Signal relay during the life cycle of Dictyostelium.

    PubMed

    Mahadeo, Dana C; Parent, Carole A

    2006-01-01

    A fundamental property of multicellular organisms is signal relay, the process by which information is transmitted from one cell to another. The integration of external information, such as nutritional status or developmental cues, is critical to the function of organisms. In addition, the spatial organizations of multicellular organisms require intricate signal relay mechanisms. Signal relay is remarkably exhibited during the life cycle of the social amoebae Dictyostelium discoideum, a eukaryote that retains a simple way of life, yet it has greatly contributed to our knowledge of the mechanisms cells use to communicate and integrate information. This chapter focuses on the molecules and mechanisms that Dictyostelium employs during its life cycle to relay temporal and spatial cues that are required for survival.

  5. 14. CENTRIFUGAL FREQUENCY RELAY IN WAYSIDE CABINET, NEW HAVEN YARD ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. CENTRIFUGAL FREQUENCY RELAY IN WAYSIDE CABINET, NEW HAVEN YARD - New York, New Haven & Hartford Railroad, Automatic Signalization System, Long Island Sound shoreline between Stamford & New Haven, Stamford, Fairfield County, CT

  6. 15. FRONT VIEW, DETAIL, CENTRIFUGAL FREQUENCY RELAY IN WAYSIDE CABINET, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. FRONT VIEW, DETAIL, CENTRIFUGAL FREQUENCY RELAY IN WAYSIDE CABINET, NEW HAVEN YARD - New York, New Haven & Hartford Railroad, Automatic Signalization System, Long Island Sound shoreline between Stamford & New Haven, Stamford, Fairfield County, CT

  7. Synthesis of polysubstituted cyclopenta[b]indoles via relay gold(I)/Brønsted acid catalysis.

    PubMed

    Dhiman, Seema; Ramasastry, S S V

    2015-01-11

    An efficient relay catalytic process involving Au(i)/Brønsted acid to access various polysubstituted cyclopentannulated indoles from easily accessible 1-(2-aminophenyl)prop-2-ynols and readily available 1,3-dicarbonyls has been developed. In an unprecedented event, the intermediate 2-indolylmethyl cations undergo the cation-Ene reaction with various 1,3-dicarbonyls followed by an intramolecular Friedel-Crafts-type reaction generating functionalized cyclopenta[b]indoles.

  8. Quantum relays and noise suppression using linear optics

    SciTech Connect

    Jacobs, B.C.; Pittman, T.B.; Franson, J.D.

    2002-11-01

    Probabilistic quantum nondemolition (QND) measurements can be performed using linear optics and postselection. Here we show how QND devices of this kind can be used in a straightforward way to implement a quantum relay, which is capable of extending the range of a quantum cryptography system by suppressing the effects of detector noise. Unlike a quantum repeater, a quantum relay system does not require entanglement purification or the ability to store photons.

  9. Controllability Analysis for Operation Margin of Zone 3 Impedance Relay

    NASA Astrophysics Data System (ADS)

    Li, Shenghu; Yorino, Naoto; Zoka, Yoshifumi

    Undesirable operation of zone 3 impedance relay (mho relays) is a possible factor for causing cascading failure as seen in several previous large scale blackouts, where power flow redistribution and power swing caused by outage or switching operations satisfy the condition for the relay operation. So far, the condition itself has not fully been investigated, and therefore, there has been little attempt to avoid the relay operation by means of direct power flow control. This paper analyzes the condition for zone 3 relay operation from the viewpoint of its sensitivity to power flow. An operating margin for security is defined for each relay to carry out effective monitoring. It is newly pointed out that undesirable operation can be effectively avoided by reactive power controls as well as real power controls. The method to compute the operation margin is also given through the analysis of the optimal Var location to control the operation margin. Effectiveness of the proposed method is demonstrated using the IEEE test systems.

  10. Modified Dynamic Decode-and-Forward Relaying Protocol for Type II Relay in LTE-Advanced and Beyond

    PubMed Central

    Nam, Sung Sik; Alouini, Mohamed-Slim; Choi, Seyeong

    2016-01-01

    In this paper, we propose a modified dynamic decode-and-forward (MoDDF) relaying protocol to meet the critical requirements for user equipment (UE) relays in next-generation cellular systems (e.g., LTE-Advanced and beyond). The proposed MoDDF realizes the fast jump-in relaying and the sequential decoding with an application of random codeset to encoding and re-encoding process at the source and the multiple UE relays, respectively. A subframe-by-subframe decoding based on the accumulated (or buffered) messages is employed to achieve energy, information, or mixed combining. Finally, possible early termination of decoding at the end user can lead to the higher spectral efficiency and more energy saving by reducing the frequency of redundant subframe transmission and decoding. These attractive features eliminate the need of directly exchanging control messages between multiple UE relays and the end user, which is an important prerequisite for the practical UE relay deployment. PMID:27898712

  11. 75 FR 54040 - Telecommunications Relay Services and Speech-to-Speech Services for Individuals With Hearing and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-03

    ... No. 03-123; DA 10-1235] Telecommunications Relay Services and Speech-to-Speech Services for... waivers of certain Telecommunications Relay Services (TRS) mandatory minimum standards for Video Relay Service (VRS) and Internet Protocol Relay (IP Relay). The waived TRS mandatory minimum standards are:...

  12. Analysis on Soft-Decision-and-Forward Cooperative Networks with Multiple Relays

    NASA Astrophysics Data System (ADS)

    Song, Kyoung-Young; Kim, Jaehong; No, Jong-Seon; Chung, Habong

    In this paper, we analyze the best relay selection scheme for the soft-decision-and-forward (SDF) cooperative networks with multiple relays. The term ‘best relay selection’ implies that the relay having the largest end-to-end signal-to-noise ratio is selected to transmit in the second phase transmission. The approximate performances in terms of pairwise error probability (PEP) and bit error rate (BER) are analyzed and compared with the conventional multiple-relay transmission scheme where all the relays participate in the second phase transmission. Using the asymptotics of the Fox's H-function, the diversity orders of the best relay selection and conventional relay scheme for the SDF cooperative networks are derived. It is shown that both have the same full diversity order. The numerical results show that the best relay selection scheme outperforms the conventional one in terms of bit error rate.

  13. Microfabricated AC impedance sensor

    DOEpatents

    Krulevitch, Peter; Ackler, Harold D.; Becker, Frederick; Boser, Bernhard E.; Eldredge, Adam B.; Fuller, Christopher K.; Gascoyne, Peter R. C.; Hamilton, Julie K.; Swierkowski, Stefan P.; Wang, Xiao-Bo

    2002-01-01

    A microfabricated instrument for detecting and identifying cells and other particles based on alternating current (AC) impedance measurements. The microfabricated AC impedance sensor includes two critical elements: 1) a microfluidic chip, preferably of glass substrates, having at least one microchannel therein and with electrodes patterned on both substrates, and 2) electrical circuits that connect to the electrodes on the microfluidic chip and detect signals associated with particles traveling down the microchannels. These circuits enable multiple AC impedance measurements of individual particles at high throughput rates with sufficient resolution to identify different particle and cell types as appropriate for environmental detection and clinical diagnostic applications.

  14. Associative Covalent Relay: An Oxadiazolone Strategy for Rhodium(III)-Catalyzed Synthesis of Primary Pyridinylamines.

    PubMed

    Yu, Xiaolong; Chen, Kehao; Wang, Qi; Guo, Shan; Zha, Shanke; Zhu, Jin

    2017-04-05

    A relay formalism is proposed herein for categorizing the interplay among reactants, target product, and catalytic center in transition-metal catalysis, an important factor that can dictate overall catalysis viability and efficiency. In this formalism, transition-metal catalysis can proceed by dissociative relay, associative covalent relay, and associative dative relay modes. An intriguing associative covalent relay process operates in rhodium(III)-catalyzed oxadiazolone-directed alkenyl C-H coupling with alkynes and allows efficient access to primary pyridinylamines. Although the primary pyridinylamine synthesis mechanism is posteriori rationalized, the relay formalism formulated herein can provide an important mechanistic conceptual framework for future catalyst design and reaction development.

  15. Commercialization and Standardization Progress Towards an Optical Communications Earth Relay

    NASA Technical Reports Server (NTRS)

    Edwards, Bernard L.; Israel, David J.

    2015-01-01

    NASA is planning to launch the next generation of a space based Earth relay in 2025 to join the current Space Network, consisting of Tracking and Data Relay Satellites in space and the corresponding infrastructure on Earth. While the requirements and architecture for that relay satellite are unknown at this time, NASA is investing in communications technologies that could be deployed to provide new communications services. One of those new technologies is optical communications. The Laser Communications Relay Demonstration (LCRD) project, scheduled for launch in 2018 as a hosted payload on a commercial communications satellite, is a critical pathfinder towards NASA providing optical communications services on the next generation space based relay. This paper will describe NASA efforts in the on-going commercialization of optical communications and the development of inter-operability standards. Both are seen as critical to making optical communications a reality on future NASA science and exploration missions. Commercialization is important because NASA would like to eventually be able to simply purchase an entire optical communications terminal from a commercial provider. Inter-operability standards are needed to ensure that optical communications terminals developed by one vendor are compatible with the terminals of another. International standards in optical communications would also allow the space missions of one nation to use the infrastructure of another.

  16. Energy efficiency analysis of relay-assisted cellular networks

    NASA Astrophysics Data System (ADS)

    Yu, Huan; Li, Yunzhou; Kountouris, Marios; Xu, Xibin; Wang, Jing

    2014-12-01

    To meet the demand for higher throughput, improved coverage and enhanced reliability, future wireless cellular networks face significant technical challenges. One promising solution is to place relay stations between transmitters and receivers in the cellular network. Meanwhile, as energy consumption reduction has been an important concern for the wireless industry, energy-efficient communications is of prime interest for future networks. In this paper, we study whether and how relays can improve the energy efficiency of cellular networks. Specifically, the energy efficiency of relay-assisted cellular networks is analyzed using tools of stochastic geometry. We first derive the coverage probability for the macro base station (MBS) to user (UE), the MBS to relay station (RS), and the RS to UE links, and then we model the power consumption at the MBS and RS. Based on the analytical model and expressions, the energy efficiency of relay-assisted cellular networks is then evaluated and is shown to be strictly quasi-concave on the transmit power for MBS to UE link or the RS to UE link. Numerical results show that the energy efficiency first improves while it hits a ceiling as the MBS density increases.

  17. Learning relay start strategies in swimming: What feedback is best?

    PubMed

    Fischer, Sebastian; Braun, Claudia; Kibele, Armin

    2017-04-01

    In the past, studies and book recommendations on relay starts in swimming have been predominantly focused on the change-over time (COT) as a performance criterion. Aside from the circular backswing start with parallel foot placement, few studies have analysed differences in the take-off movement including step approaches as well. Although trends could be identified, the results remained still somewhat inconclusive. In contrast, no study has examined as has examined whether a reduction of COT in between wall contact of the income swimmer and the take-off of the outgoing swimmer is an optimal relay start strategy, as advocated by various swimming experts. Therefore, the purpose of this study was to compare two different relay start strategies: offensive strategy minimizing COT and conservative strategy to maximize horizontal peak force (HPF). In this regard, a learning intervention with 24 elite-level swimmers (12 females, 12 male) was conducted to compare both strategies regarding relay start time, HPF and COT. Subjects were randomly assigned to two feedback groups: COT versus HPF at take-off. The results of this study showed a clear advantage for HPF feedback for relay start performance measured by wall contact of the incoming swimmer and head passage at 7.5 m of the outgoing swimmer. In addition, similar reductions in COTs were found in both training groups. In conclusion, swimmers should focus on force production rather than minimizing COT. For the latter, deteriorating consequences for force production must be considered.

  18. A novel relay method for determining low-clearance values.

    PubMed

    Di, Li; Trapa, Patrick; Obach, R Scott; Atkinson, Karen; Bi, Yi-An; Wolford, Angela C; Tan, Beijing; McDonald, Thomas S; Lai, Yurong; Tremaine, Larry M

    2012-09-01

    A novel relay method has been developed using cryopreserved human hepatocytes to measure intrinsic clearance of low-clearance compounds. The relay method involved transferring the supernatant from hepatocyte incubations to freshly thawed hepatocytes at the end of the 4-h incubation to prolong the exposure time to active enzymes in hepatocytes. An accumulative incubation time of 20 h or longer in hepatoctyes can be achieved using the method. The relay method was validated using seven commercial drugs (diazepam, disopyramide, theophylline, timolol, tolbutamide, S-warfarin, and zolmitriptan) that were metabolized by various cytochrome P450s with low human in vivo intrinsic clearance at approximately 2 to 15 ml · min⁻¹ · kg⁻¹. The results showed that the relay method produced excellent predictions of human in vivo clearance. The difference between in vitro and in vivo intrinsic clearance was within 2-fold for most compounds, which is similar to the standard prediction accuracy for moderate to high clearance compounds using hepatocytes. The relay method is a straightforward, relatively low cost, and easy-to-use new tool to address the challenges of low clearance in drug discovery and development.

  19. Implementing Strategic Planning Capabilities Within the Mars Relay Operations Service

    NASA Technical Reports Server (NTRS)

    Hy, Franklin; Gladden, Roy; Allard, Dan; Wallick, Michael

    2011-01-01

    Since the Mars Exploration Rovers (MER), Spirit and Opportunity, began their travels across the Martian surface in January of 2004, orbiting spacecraft such as the Mars 2001 Odyssey orbiter have relayed the majority of their collected scientific and operational data to and from Earth. From the beginning of those missions, it was evident that using orbiters to relay data to and from the surface of Mars was a vastly more efficient communications strategy in terms of power consumption and bandwidth compared to direct-to-Earth means. However, the coordination between the various spacecraft, which are largely managed independently and on differing commanding timelines, has always proven to be a challenge. Until recently, the ground operators of all these spacecraft have coordinated the movement of data through this network using a collection of ad hoc human interfaces and various, independent software tools. The Mars Relay Operations Service (MaROS) has been developed to manage the evolving needs of the Mars relay network, and specifically to standardize and integrate the relay planning and coordination data into a centralized infrastructure. This paper explores the journey of developing the MaROS system, from inception to delivery and acceptance by the Mars mission users.

  20. AC magnetohydrodynamic microfluidic switch

    SciTech Connect

    Lemoff, A V; Lee, A P

    2000-03-02

    A microfluidic switch has been demonstrated using an AC Magnetohydrodynamic (MHD) pumping mechanism in which the Lorentz force is used to pump an electrolytic solution. By integrating two AC MHD pumps into different arms of a Y-shaped fluidic circuit, flow can be switched between the two arms. This type of switch can be used to produce complex fluidic routing, which may have multiple applications in {micro}TAS.

  1. Bilayer Protograph Codes for Half-Duplex Relay Channels

    NASA Technical Reports Server (NTRS)

    Divsalar, Dariush; VanNguyen, Thuy; Nosratinia, Aria

    2013-01-01

    Direct to Earth return links are limited by the size and power of lander devices. A standard alternative is provided by a two-hops return link: a proximity link (from lander to orbiter relay) and a deep-space link (from orbiter relay to Earth). Although direct to Earth return links are limited by the size and power of lander devices, using an additional link and a proposed coding for relay channels, one can obtain a more reliable signal. Although significant progress has been made in the relay coding problem, existing codes must be painstakingly optimized to match to a single set of channel conditions, many of them do not offer easy encoding, and most of them do not have structured design. A high-performing LDPC (low-density parity-check) code for the relay channel addresses simultaneously two important issues: a code structure that allows low encoding complexity, and a flexible rate-compatible code that allows matching to various channel conditions. Most of the previous high-performance LDPC codes for the relay channel are tightly optimized for a given channel quality, and are not easily adapted without extensive re-optimization for various channel conditions. This code for the relay channel combines structured design and easy encoding with rate compatibility to allow adaptation to the three links involved in the relay channel, and furthermore offers very good performance. The proposed code is constructed by synthesizing a bilayer structure with a pro to graph. In addition to the contribution to relay encoding, an improved family of protograph codes was produced for the point-to-point AWGN (additive white Gaussian noise) channel whose high-rate members enjoy thresholds that are within 0.07 dB of capacity. These LDPC relay codes address three important issues in an integrative manner: low encoding complexity, modular structure allowing for easy design, and rate compatibility so that the code can be easily matched to a variety of channel conditions without extensive

  2. Recent results in Mars Relay Network planning and scheduing

    NASA Technical Reports Server (NTRS)

    Lee, C. H.; Cheung, K. M.

    2003-01-01

    At different time periods in the future, Mars missions will overlap and previous studies indicate that during such periods existing deep space communication infrastructure will not be able to handle all Mars communication needs. A plausible solution is to perform optimal resource allocation for the Mars relay communication network; a network consisting of multiple surface units and orbiters on Mars and the Deep Space Stations. Unlike direct-to-earth, a relay communication, either in real-time or store-and-forward, can increase network science data return, reduce surface unit's direct-to-earth communication demands, and enable communication even when the surface unit is not facing Earth. It is the objective of this paper to take advantage of the relay operation to efficiently plan and schedule the network communications.

  3. VoiceRelay: voice key operation using visual basic.

    PubMed

    Abrams, Lise; Jennings, David T

    2004-11-01

    Using a voice key is a popular method for recording vocal response times in a variety of language production tasks. This article describes a class module called VoiceRelay that can be easily utilized in Visual Basic programs for voice key operation. This software-based voice key offers the precision of traditional voice keys (although accuracy is system dependent), as well as the flexibility of volume and sensitivity control. However, VoiceRelay is a considerably less expensive alternative for recording vocal response times because it operates with existing PC hardware and does not require the purchase of external response boxes or additional experiment-generation software. A sample project demonstrating implementation of the VoiceRelay class module may be downloaded from the Psychonomic Society Web archive, www.psychonomic.org/archive.

  4. CHED Events: Salt Lake City

    NASA Astrophysics Data System (ADS)

    Wink, Donald J.

    2009-03-01

    The Division of Chemical Education (CHED) Committee meetings planned for the Spring 2009 ACS Meeting in Salt Lake City will be in the Marriott City Center Hotel. Check the location of other CHED events, the CHED Social Event, the Undergraduate Program, Sci-Mix, etc. because many will be in the Salt Palace Convention Center.

  5. An analytical study of relay neuron's reliability: dependence on input and model parameters.

    PubMed

    Agarwal, Rahul; Sarma, Sridevi V

    2011-01-01

    Relay neurons are widely found in our nervous system, including the Thalamus, spinal cord and lateral geniculate body. They receive a modulating input (background activity) and a reference input. The modulating input modulates relay of the reference input. This modulation is critical for correct functioning of relay neurons, but is poorly understood. In this paper, we use a biophysical-based model and systems theoretic tools to calculate how well a single relay neuron relays a reference input signal as a function of the neuron's electro physiological properties (i.e. model parameters), the modulating signal, and the reference signal parameters. Our analysis is more rigorous than previous related works and is generalizable to all relay cells in the body. Our analytical expression matches relay performance obtained in simulation and suggest that increasing the frequency of a sinusoidal modulating input or decreasing its DC offset increases the relay cell reliability.

  6. 77 FR 18106 - Structure and Practices of the Video Relay Service Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-27

    ... From the Federal Register Online via the Government Publishing Office ] FEDERAL COMMUNICATIONS COMMISSION 47 CFR Part 64 Structure and Practices of the Video Relay Service Program AGENCY: Federal... Relay Service (VRS) industry. DATES: Effective September 26, 2011. FOR FURTHER INFORMATION...

  7. 77 FR 33662 - Structure and Practices of the Video Relay Service Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-07

    ... From the Federal Register Online via the Government Publishing Office FEDERAL COMMUNICATIONS COMMISSION 47 CFR Part 64 Structure and Practices of the Video Relay Service Program AGENCY: Federal..., August 5, 2011. The interim regulations require Internet- based Telecommunications Relay Service...

  8. Overview and status of the laser communication relay demonstration

    NASA Astrophysics Data System (ADS)

    Luzhanskiy, E.; Edwards, B.; Israel, D.; Cornwell, D.; Staren, J.; Cummings, N.; Roberts, T.; Patschke, R.

    2016-03-01

    NASA is presently developing the first all-optical high data rate satellite relay system, LCRD. To be flown on a geosynchronous satellite, it will communicate with DPSK and PPM modulation formats up to 1.244 Gbps. LCRD flight payload is being developed by NASA's Goddard Space Flight Center. The two ground stations, one on Table Mountain in CA, developed by NASA's Jet Propulsion Laboratory, and another on a Hawaiian island will enable bi-directional relay operation and ground sites diversity experiments.

  9. Overview and Status of the Laser Communication Relay Demonstration

    NASA Technical Reports Server (NTRS)

    Luzhanskiy, E.; Edwards, B.; Israel, D.; Cornwell, D.; Staren, J.; Cummings, N.; Roberts, T.; Patschke, R.

    2016-01-01

    NASA is presently developing first all optical high data rate satellite relay system, LCRD. To be flown on commercial geosynchronous satellite, it will communicate at DPSK and PPM modulation formats up to 1.244 Gbps. LCRD flight payload is being developed by NASA's Goddard Space Flight Center. The two ground stations, one on Table Mountain in CA, developed by NASA's Jet Propulsion Laboratory and another on Hawaiian island will enable bi-directional relay operation and ground sites diversity experiments. In this paper we will report on the current state of LCRD system development, planned operational scenarios and expected system performance.

  10. Performance Analysis of MIMO Relay Network via Propagation Measurement in L-Shaped Corridor Environment

    NASA Astrophysics Data System (ADS)

    Lertwiram, Namzilp; Tran, Gia Khanh; Mizutani, Keiichi; Sakaguchi, Kei; Araki, Kiyomichi

    Setting relays can address the shadowing problem between a transmitter (Tx) and a receiver (Rx). Moreover, the Multiple-Input Multiple-Output (MIMO) technique has been introduced to improve wireless link capacity. The MIMO technique can be applied in relay network to enhance system performance. However, the efficiency of relaying schemes and relay placement have not been well investigated with experiment-based study. This paper provides a propagation measurement campaign of a MIMO two-hop relay network in 5GHz band in an L-shaped corridor environment with various relay locations. Furthermore, this paper proposes a Relay Placement Estimation (RPE) scheme to identify the optimum relay location, i.e. the point at which the network performance is highest. Analysis results of channel capacity show that relaying technique is beneficial over direct transmission in strong shadowing environment while it is ineffective in non-shadowing environment. In addition, the optimum relay location estimated with the RPE scheme also agrees with the location where the network achieves the highest performance as identified by network capacity. Finally, the capacity analysis shows that two-way MIMO relay employing network coding has the best performance while cooperative relaying scheme is not effective due to shadowing effect weakening the signal strength of the direct link.

  11. 47 CFR 74.436 - Special requirements for automatic relay stations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 4 2013-10-01 2013-10-01 false Special requirements for automatic relay... SERVICES Remote Pickup Broadcast Stations § 74.436 Special requirements for automatic relay stations. (a) An automatic relay station must be designed, installed, and protected so that the transmitter...

  12. 78 FR 14701 - Misuse of Internet Protocol (IP) Captioned Telephone Service; Telecommunications Relay Services...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-07

    ... Relay Services and Speech-to-Speech Services for Individuals With Hearing and Speech Disabilities AGENCY... Protocol (IP) Captioned Telephone Service; Telecommunications Relay Services and Speech-to-Speech Services..., in order to be eligible for compensation from the Interstate Telecommunications Relay Service...

  13. 76 FR 67118 - Structure and Practices of the Video Relay Service Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-31

    ... COMMISSION 47 CFR Part 64 Structure and Practices of the Video Relay Service Program AGENCY: Federal... . SUPPLEMENTARY INFORMATION: This is a summary of the Commission's Structure and Practices of the Video Relay..., 254(k), 616 and 620, unless otherwise noted. Subpart F--Telecommunications Relay Services and...

  14. 47 CFR 74.436 - Special requirements for automatic relay stations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 4 2011-10-01 2011-10-01 false Special requirements for automatic relay... SERVICES Remote Pickup Broadcast Stations § 74.436 Special requirements for automatic relay stations. (a) An automatic relay station must be designed, installed, and protected so that the transmitter...

  15. 76 FR 68328 - Structure and Practices of the Video Relay Service Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-04

    ... COMMISSION 47 CFR Part 64 Structure and Practices of the Video Relay Service Program AGENCY: Federal..., the information collection associated with the Commission's Structure and Practices of the Video Relay... Structure and Practices of the Video Relay Service Program, CG Docket No. 10-51; FCC 11-118, published at...

  16. 76 FR 24437 - Structure and Practices of the Video Relay Service Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-02

    ... COMMISSION 47 CFR Part 64 Structure and Practices of the Video Relay Service Program AGENCY: Federal... proposed modifications to its certification process for Internet-based relay providers to ensure that all entities seeking certification to provide Internet-based telecommunications relay services (TRS) in...

  17. 76 FR 68116 - Structure and Practices of the Video Relay Service Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-03

    ... No. 10-51; FCC 11-118] Structure and Practices of the Video Relay Service Program AGENCY: Federal..., the information collection associated with the Commission's Structure and Practices of the Video Relay... Practices of the Video Relay Service Program, CG Docket No. 10-51, FCC 11-118, published at 76 FR...

  18. Development of a Relay Performance Web Tool for the Mars Network

    NASA Technical Reports Server (NTRS)

    Allard, Daniel A.; Edwards, Charles D.

    2009-01-01

    Modern Mars surface missions rely upon orbiting spacecraft to relay communications to and from Earth systems. An important component of this multi-mission relay process is the collection of relay performance statistics supporting strategic trend analysis and tactical anomaly identification and tracking.

  19. 76 FR 30841 - Structure and Practices of the Video Relay Service Program; Correction

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-27

    ... COMMISSION 47 CFR Part 64 Structure and Practices of the Video Relay Service Program; Correction AGENCY... document ] adopted rules to address fraud, waste, and abuse in the Video Relay Service (VRS) industry... Internet-based relay service, including documentation on loans for equipment, inventory,...

  20. 75 FR 39859 - Structure and Practices of the Video Relay Service Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-13

    ... COMMISSION 47 CFR Part 64 Structure and Practices of the Video Relay Service Program AGENCY: Federal... addressing the certification of provider information for Telecommunications Relay Services (TRS) calls. By... the Video Relay Service Program, Order, document FCC 10-88, adopted May 24, 2010, and released May...

  1. 75 FR 39945 - Structure and Practices of the Video Relay Service Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-13

    ... COMMISSION Structure and Practices of the Video Relay Service Program AGENCY: Federal Communications... Telecommunications Relay Service (TRS) Fund (Fund) payments may be suspended to providers that do not submit to... summary of the Commission's Structure and Practices of the Video Relay Service Program, Declaratory...

  2. 76 FR 8659 - Structure and Practices of the Video Relay Service Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-15

    ... COMMISSION 47 CFR Part 64 Structure and Practices of the Video Relay Service Program AGENCY: Federal..., the information collection associated with the Commission's Structure and Practices of the Video Relay... Date: January 31, 2014. Title: Structure and Practices of the Video Relay Service Program, CG Docket...

  3. 76 FR 59557 - Structure and Practices of the Video Relay Service Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-27

    ... COMMISSION 47 CFR Part 64 Structure and Practices of the Video Relay Service Program AGENCY: Federal... proceeding concerning Structure and Practices of the Video Relay Service Program, Second Report and Order and... oppositions and replies. In light of impending deadlines for initial and ] recertification Video Relay...

  4. 76 FR 47469 - Structure and Practices of the Video Relay Service Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-05

    ... COMMISSION 47 CFR Part 64 CG Docket No. 10-51; FCC 11-118] Structure and Practices of the Video Relay Service... Commission adopts modifications to its certification process for all Internet-based telecommunications relay... Commission's Structure and Practices of the Video Relay Service Program, Second Report and Order...

  5. 47 CFR 74.436 - Special requirements for automatic relay stations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 4 2014-10-01 2014-10-01 false Special requirements for automatic relay... SERVICES Remote Pickup Broadcast Stations § 74.436 Special requirements for automatic relay stations. (a) An automatic relay station must be designed, installed, and protected so that the transmitter...

  6. 76 FR 68642 - Structure and Practices of the Video Relay Service Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-07

    ...; FCC 11-155] Structure and Practices of the Video Relay Service Program AGENCY: Federal Communications... information collection associated with the Commission's Structure and Practices of the Video Relay Service... Practices of the Video Relay Service Program; Sprint Nextel Corporation Expedited Petition for...

  7. 78 FR 55249 - Transmission Relay Loadability Reliability Standard; Notice of Compliance Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-10

    ... Energy Regulatory Commission Transmission Relay Loadability Reliability Standard; Notice of Compliance... Interconnections. \\1\\ Transmission Relay Loadability Reliability Standard, Order No. 733, 130 FERC ] 61, 221 (2010..., Order No. 733-B, 136 FERC ] 61,185 (2011). \\2\\ Transmission Relay Loadability Reliability Standard,...

  8. 47 CFR 74.436 - Special requirements for automatic relay stations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 4 2012-10-01 2012-10-01 false Special requirements for automatic relay... SERVICES Remote Pickup Broadcast Stations § 74.436 Special requirements for automatic relay stations. (a) An automatic relay station must be designed, installed, and protected so that the transmitter...

  9. 47 CFR 74.436 - Special requirements for automatic relay stations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Special requirements for automatic relay... SERVICES Remote Pickup Broadcast Stations § 74.436 Special requirements for automatic relay stations. (a) An automatic relay station must be designed, installed, and protected so that the transmitter...

  10. 77 FR 60630 - Structure and Practices of the Video Relay Service Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-04

    ... COMMISSION 47 CFR Part 64 Structure and Practices of the Video Relay Service Program AGENCY: Federal... 2, 2011, 76 FR 24393. The final regulations address fraud, waste, and abuse in the Video Relay... Relay Service (TRS) Fund administrator and the Commission on the need to inquire further about, and...

  11. Tevatron AC dipole system

    SciTech Connect

    Miyamoto, R.; Kopp, S.E.; Jansson, A.; Syphers, M.J.; /Fermilab

    2007-06-01

    The AC dipole is an oscillating dipole magnet which can induce large amplitude oscillations without the emittance growth and decoherence. These properties make it a good tool to measure optics of a hadron synchrotron. The vertical AC dipole for the Tevatron is powered by an inexpensive high power audio amplifier since its operating frequency is approximately 20 kHz. The magnet is incorporated into a parallel resonant system to maximize the current. The use of a vertical pinger magnet which has been installed in the Tevatron made the cost relatively inexpensive. Recently, the initial system was upgraded with a more powerful amplifier and oscillation amplitudes up to 2-3{sigma} were achieved with the 980 GeV proton beam. This paper discusses details of the Tevatron AC dipole system and also shows its test results.

  12. ACS CCDs daily monitor

    NASA Astrophysics Data System (ADS)

    Sirianni, Marco

    2006-07-01

    This program consists of a set of basic tests to monitor, the read noise, thedevelopment of hot pixels and test for any source of noise in ACS CCDdetectors. The files, biases and dark will be used to create referencefiles for science calibration. This programme will be for the entire lifetime of ACS.For cycle 15 the program will cover 18 months 12.1.06->05.31.08and it has been divied into three different proposal each covering six months.The three poroposal are 11041-11042-11043.

  13. ac bidirectional motor controller

    NASA Technical Reports Server (NTRS)

    Schreiner, K.

    1988-01-01

    Test data are presented and the design of a high-efficiency motor/generator controller at NASA-Lewis for use with the Space Station power system testbed is described. The bidirectional motor driver is a 20 kHz to variable frequency three-phase ac converter that operates from the high-frequency ac bus being designed for the Space Station. A zero-voltage-switching pulse-density-modulation technique is used in the converter to shape the low-frequency output waveform.

  14. 76 FR 58424 - Transmission Relay Loadability Reliability Standard

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-21

    ... Energy Regulatory Commission 18 CFR Parts 39 and 40 Transmission Relay Loadability Reliability Standard... section 215 of the Federal Power Act, the Commission proposes to approve Reliability Standard PRC-023-2... Reliability Corporation (NERC), the Electric Reliability Organization (ERO) certified by the Commission....

  15. Spacecraft Orbits for Earth/Mars-Lander Radio Relay

    NASA Technical Reports Server (NTRS)

    Noreen, Gary; Diehl, Roger; Neelon, Joseph

    2004-01-01

    A report discusses a network of spacecraft, in orbit around Mars, used to relay radio communications between Earth stations and mobile exploratory robots (rovers) as well as stationary scientific instruments that have been landed on the Mars surface. The relay spacecraft include two already in orbit plus several others planned to arrive at Mars in the years 2004 through 2008. A major portion of the report is devoted to the orbit of the G. Macroni Orbiter, which is in the midst of an iterative design process and is intended to be the first Mars orbiter designed primarily for radio relay. Candidate orbits are analyzed with a view toward choosing one that maximizes the amount of time available for communication with surface units, taking account of visibility as a function of position, the limit on communication distance at low power, and the fact that surface units can transmit more easily when they are in sunlight. Two promising new orbits for Mars relay satellites are identified: a 1/2-sol apoapsis-at-constant-time-of-day equatorial orbit and a 1/4-sol apoapsis-at-constant-time-of-day, critical-inclination orbit.

  16. Protection Relaying Scheme Based on Fault Reactance Operation Type

    NASA Astrophysics Data System (ADS)

    Tsuji, Kouichi

    The theories of operation of existing relays are roughly divided into two types: one is the current differential types based on Kirchhoff's first law and the other is impedance types based on second law. We can apply the Kirchhoff's laws to strictly formulate fault phenomena, so the circuit equations are represented non linear simultaneous equations with variables fault point k and fault resistance Rf. This method has next two defect. 1) heavy computational burden for the iterative calculation on N-R method, 2) relay operator can not easily understand principle of numerical matrix operation. The new protection relay principles we proposed this paper focuses on the fact that the reactance component on fault point is almost zero. Two reactance Xf(S), Xf(R) on branch both ends are calculated by operation of solving linear equations. If signs of Xf(S) and Xf(R) are not same, it can be judged that the fault point exist in the branch. This reactance Xf corresponds to difference of branch reactance between actual fault point and imaginaly fault point. And so relay engineer can to understand fault location by concept of “distance". The simulation results using this new method indicates the highly precise estimation of fault locations compared with the inspected fault locations on operating transmission lines.

  17. The Tracking & Data Relay Satellite System. The New Space Network.

    ERIC Educational Resources Information Center

    Froehlich, Walter

    This publication describes the giant-capacity space communications installation called the "Tracking and Data Relay Satellite System" (TDRSS). Chapters include: (1) "A New Communications Bridge to Orbit" (illustrating what it is and how it looks); (2) "TDRSS Goes to Work" (describing how it functions); (3) "The…

  18. Hydrologic data relay by satellite from remote areas

    NASA Technical Reports Server (NTRS)

    Halliday, R. A. (Principal Investigator)

    1977-01-01

    The author has identified the following significant results. Experimental use of LANDSAT data collection system and the GOES system has demonstrated the feasibility of using this technology to relay hydrologic data from remote areas on a near real time basis. The system has proved to be accurate, reliable, and cost effective.

  19. 9. Detail of electrical cables from relay station to upper ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. Detail of electrical cables from relay station to upper floor of tower. Note the penetrations in the wall, right of center where cables formerly passed into the control room. - New York, New Haven, & Hartford Railroad, Shell Interlocking Tower, New Haven Milepost 16, approximately 100 feel east of New Rochelle Junction, New Rochelle, Westchester County, NY

  20. DETAIL OF ELECTROMECHANICAL RELAYS ON SHELVES, FIRST FLOOR, CAMERA FACING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL OF ELECTRO-MECHANICAL RELAYS ON SHELVES, FIRST FLOOR, CAMERA FACING SOUTHWEST. THESE "UNION ROUTE INTERLOCKING SELECTION UNITS" ALLOWED RELATIVELY EASY REPLACEMENT OF MALFUNCTIONING CIRCUITS. - New Haven Rail Yard, Interlocking Control Building, Vicinity of Union Avenue, New Haven, New Haven County, CT

  1. 32. View of relay assembly group and interconnecting group electronic ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    32. View of relay assembly group and interconnecting group electronic modules located on second floor of transmitter building no. 102 in MIP area. - Clear Air Force Station, Ballistic Missile Early Warning System Site II, One mile west of mile marker 293.5 on Parks Highway, 5 miles southwest of Anderson, Anderson, Denali Borough, AK

  2. Modeling and Simulation of a Novel Relay Node Based Secure Routing Protocol Using Multiple Mobile Sink for Wireless Sensor Networks

    PubMed Central

    Perumal, Madhumathy; Dhandapani, Sivakumar

    2015-01-01

    Data gathering and optimal path selection for wireless sensor networks (WSN) using existing protocols result in collision. Increase in collision further increases the possibility of packet drop. Thus there is a necessity to eliminate collision during data aggregation. Increasing the efficiency is the need of the hour with maximum security. This paper is an effort to come up with a reliable and energy efficient WSN routing and secure protocol with minimum delay. This technique is named as relay node based secure routing protocol for multiple mobile sink (RSRPMS). This protocol finds the rendezvous point for optimal transmission of data using a “splitting tree” technique in tree-shaped network topology and then to determine all the subsequent positions of a sink the “Biased Random Walk” model is used. In case of an event, the sink gathers the data from all sources, when they are in the sensing range of rendezvous point. Otherwise relay node is selected from its neighbor to transfer packets from rendezvous point to sink. A symmetric key cryptography is used for secure transmission. The proposed relay node based secure routing protocol for multiple mobile sink (RSRPMS) is experimented and simulation results are compared with Intelligent Agent-Based Routing (IAR) protocol to prove that there is increase in the network lifetime compared with other routing protocols. PMID:26495426

  3. Modeling and Simulation of a Novel Relay Node Based Secure Routing Protocol Using Multiple Mobile Sink for Wireless Sensor Networks.

    PubMed

    Perumal, Madhumathy; Dhandapani, Sivakumar

    2015-01-01

    Data gathering and optimal path selection for wireless sensor networks (WSN) using existing protocols result in collision. Increase in collision further increases the possibility of packet drop. Thus there is a necessity to eliminate collision during data aggregation. Increasing the efficiency is the need of the hour with maximum security. This paper is an effort to come up with a reliable and energy efficient WSN routing and secure protocol with minimum delay. This technique is named as relay node based secure routing protocol for multiple mobile sink (RSRPMS). This protocol finds the rendezvous point for optimal transmission of data using a "splitting tree" technique in tree-shaped network topology and then to determine all the subsequent positions of a sink the "Biased Random Walk" model is used. In case of an event, the sink gathers the data from all sources, when they are in the sensing range of rendezvous point. Otherwise relay node is selected from its neighbor to transfer packets from rendezvous point to sink. A symmetric key cryptography is used for secure transmission. The proposed relay node based secure routing protocol for multiple mobile sink (RSRPMS) is experimented and simulation results are compared with Intelligent Agent-Based Routing (IAR) protocol to prove that there is increase in the network lifetime compared with other routing protocols.

  4. Failure analysis of blistered gold plating on spot welded electrical relays

    NASA Technical Reports Server (NTRS)

    Sokolowski, Witold; O'Donnell, Tim

    1989-01-01

    Gold-plated stainless-steel sideplates, part of a JPL Galileo spacecraft electronic-relay assembly, exhibited blistering after resistance spot welding. Unacceptable relays had heavy nonuniform gold electrodeposited layers with thicknesses 4.5-11.5 microns. SEM and metallographic investigations indicated much higher heat input generated during the resistance spot welding in unacceptable relays. The attributes of acceptable welded relays are contrasted with unacceptable relays; the possible mechanism of laminar formation of polymeric material in the gold plating is discussed; and some recommendations are provided to prevent similar problems.

  5. Analysis and Measurement of Residual Stress in Bridge Membrane MEMS Relays

    NASA Astrophysics Data System (ADS)

    Ruan, Yong; Wang, Weizhong; Zhu, Yong; You, Zheng

    2017-04-01

    Microelectromechanical system (MEMS) relays are gradually replacing traditional relays because they are smaller and lighter and consume less power. However, performance parameters of MEMS relays, such as the pull-down voltage, response time, and resonant frequency, often deviate from those originally designed, due to residual stress generated during the fabrication process. We present herein a method to measure this residual stress, based on a metal bridge membrane MEMS relay, with the help of a nanoindenter and the finite-element method (FEM). The testing result lies in a reasonable range, indicating that this simple method is reliable and helpful for MEMS relay optimization.

  6. A Practical Method for Assessing the Effectiveness of Vector Surge Relays for Distributed Generation Applications

    SciTech Connect

    Freitas, Walmir; Huang, Zhenyu; Xu, Wilsun

    2005-01-01

    This paper presents simple and reliable method for predicting the islanding detection performance of vector surge relays. The relay performance is characterized by a tripping-time versus power-imbalance curve. With the curve, one can determine the time taken by a vector surge relay to detect islanding for any generation-load mismatch level. The main contribution of this paper is the development of analytical formulas for directly determining the behavior of vector surge relays. As a result, efforts needed to asses the relay performance for a given distributed generation scheme can be simplified significantly. The accuracy of the formulas has been verified by extensive simulation study results.

  7. 77 FR 43538 - Misuse of Internet Protocol (IP) Relay Service; Telecommunications Relay Services and Speech-to...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-25

    ... registrants as guest users prior to taking reasonable measures to verify their registration information. The... and registration system. In order to enable users to make calls under this ``guest user'' procedure... because in order to make IP Relay calls as a guest user, the user is given a ten-digit number that...

  8. AC/DC converter

    NASA Astrophysics Data System (ADS)

    Jain, Praveen K.

    1992-08-01

    In a system such as a 20 kHz space station primary electrical power distribution system, power conversion from AC to DC is required. Some of the basic requirements for this conversion are high efficiency, light weight and small volume, regulated output voltage, close to unity input power factor, distortionless input current, soft-starting, low electromagnetic interference, and high reliability. An AC-to-DC converter is disclosed which satisfies the main design objectives of such converters for use in space. The converter of the invention comprises an input transformer, a resonant network, a current controller, a diode rectifier, and an output filter. The input transformer is for connection to a single phase, high frequency, sinusoidal waveform AC voltage source and provides a matching voltage isolating from the AC source. The resonant network converts this voltage to a sinusoidal, high frequency bidirectional current output, which is received by the current controller to provide the desired output current. The diode rectifier is connected in parallel with the current controller to convert the bidirectional current into a unidirectional current output. The output filter is connected to the rectifier to provide an essentially ripple-free, substantially constant voltage DC output.

  9. AC/RF Superconductivity

    SciTech Connect

    Ciovati, Gianluigi

    2015-02-01

    This contribution provides a brief introduction to AC/RF superconductivity, with an emphasis on application to accelerators. The topics covered include the surface impedance of normal conductors and superconductors, the residual resistance, the field dependence of the surface resistance, and the superheating field.

  10. Search for {beta}-delayed fission of {sup 228}Ac

    SciTech Connect

    Xu Yanbing; Ding Huajie; Yuan Shuanggui; Yang Weifan; Niu Yanning; Li Yingjun; Xiao Yonghou; Zhang Shengdong; Lu Xiting

    2006-10-15

    Radium was radiochemically separated from natural thorium. Thin {sup 228}Ra{yields}{beta}{sup -228}Ac sources were prepared and exposed to mica fission track detectors, and measured by an HPGe {gamma}-ray detector. The {beta}-delayed fission events of {sup 228}Ac were observed and its {beta}-delayed fission probability was found to be (5{+-}2)x10{sup -12}.

  11. 78 FR 49693 - Speech-to-Speech and Internet Protocol (IP) Speech-to-Speech Telecommunications Relay Services...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-15

    ... Relay Services; Telecommunications Relay Services and Speech-to-Speech Services for Individuals With... this document, the Commission amends telecommunications relay services (TRS) mandatory minimum standards applicable to Speech- to-Speech (STS) relay service. This action is necessary to ensure...

  12. Design and architecture of the Mars relay network planning and analysis framework

    NASA Technical Reports Server (NTRS)

    Cheung, K. M.; Lee, C. H.

    2002-01-01

    In this paper we describe the design and architecture of the Mars Network planning and analysis framework that supports generation and validation of efficient planning and scheduling strategy. The goals are to minimize the transmitting time, minimize the delaying time, and/or maximize the network throughputs. The proposed framework would require (1) a client-server architecture to support interactive, batch, WEB, and distributed analysis and planning applications for the relay network analysis scheme, (2) a high-fidelity modeling and simulation environment that expresses link capabilities between spacecraft to spacecraft and spacecraft to Earth stations as time-varying resources, and spacecraft activities, link priority, Solar System dynamic events, the laws of orbital mechanics, and other limiting factors as spacecraft power and thermal constraints, (3) an optimization methodology that casts the resource and constraint models into a standard linear and nonlinear constrained optimization problem that lends itself to commercial off-the-shelf (COTS)planning and scheduling algorithms.

  13. Principles and Practices for Championship Performances in Wheelchair Track Events.

    ERIC Educational Resources Information Center

    Practical Pointers, 1979

    1979-01-01

    The booklet discusses training methods and approaches for wheelchair track and field. Detailed information and charts are presented on types of workouts (such as interval, distance, rhythm, speed play, and pace work) and mechanics of track events. A section on relay strategy and coaching approaches concludes the document. (CL)

  14. The Case for Deep Space Telecommunications Relay Stations

    NASA Technical Reports Server (NTRS)

    Chandler, Charles W.; Miranda, Felix A. (Technical Monitor)

    2004-01-01

    Each future mission to Jupiter and beyond must carry the traditional suite of telecommunications systems for command and control and for mission data transmission to earth. The telecommunications hardware includes the large antenna and the high-power transmitters that enable the communications link. Yet future spacecraft will be scaled down from the hallmark missions of Galileo and Cassini to Jupiter and Saturn, respectively. This implies that a higher percentage of the spacecraft weight and power must be dedicated to telecommunications system. The following analysis quantifies this impact to future missions and then explores the merits of an alternative approach using deep space relay stations for the link back to earth. It will be demonstrated that a telecommunications relay satellite would reduce S/C telecommunications weight and power sufficiently to add one to two more instruments.

  15. Strain compatibility and fault linkage in relay zones on normal faults

    NASA Astrophysics Data System (ADS)

    Long, Jonathan J.; Imber, Jonathan

    2012-03-01

    Relay zones on normal faults are unlikely to have tabular geometries as depicted in idealised models. Rotation of a relay ramp between non-parallel and non-planar relay-bounding faults will inevitably lead to strain compatibility problems causing open gaps or overlaps within the relay zone. Linkage of relay-bounding faults does not evolve from a single branch point. Rather, linkage occurs at multiple points along the fault tip lines giving rise to initially discontinuous branch lines. Where linkage occurs along a discontinuous slip-aligned branch line, displacement at different levels within the relay zone is partitioned between variable amounts of ramp rotation and slip across the branch line. The linking fault propagates when strain compatibility can no longer be maintained by continuous deformation processes, such as thickening or thinning of incompetent layers within the relay ramp. Step-like changes in vertical displacement vs. distance (D - x) profiles on horizons containing apparently intact relay ramps are probably indicative of incipient breaching and can be used predict the presence of a slip-aligned branch line in the sub-surface. Despite the complexity of the strain distribution within relay zones, the total vertical displacement across the relay remains geometrically coherent at all levels.

  16. Distributed beamforming designs to improve physical layer security in wireless relay networks

    NASA Astrophysics Data System (ADS)

    Qian, Mujun; Liu, Chen; Fu, Youhua

    2014-12-01

    This paper investigates security-oriented beamforming designs in a relay network composed of a source-destination pair, multiple relays, and a passive eavesdropper. Unlike most of the earlier works, we assume that only statistical information of the relay-eavesdropper channels is known to the relays. We propose beamforming solutions for amplify-and-forward (AF) and decode-and-forward (DF) relay networks to improve secrecy capacity. In an AF network, the beamforming design is obtained by approximating a product of two correlated Rayleigh quotients to a single Rayleigh quotient using the Taylor series expansion. Our study reveals that in an AF network, the secrecy capacity does not always grow as the eavesdropper moves away from the relays or as total relay transmit power increases. Moreover, if the destination is nearer to the relays than the eavesdropper is, a suboptimal power is derived in closed form through monotonicity analysis of secrecy capacity. While in a DF network, secrecy capacity is a single Rayleigh quotient problem which can be easily solved. We also found that if the relay-eavesdropper distances are about the same, it is unnecessary to consider the eavesdropper in a DF network. Numerical results show that for either AF or DF relaying protocol, the proposed beamforming scheme provides higher secrecy capacity than traditional approaches.

  17. The Dynamic Disulfide Relay of Quiescin Sulfhydryl Oxidase

    PubMed Central

    Alon, Assaf; Grossman, Iris; Gat, Yair; Kodali, Vamsi K.; DiMaio, Frank; Mehlman, Tevie; Haran, Gilad; Baker, David; Thorpe, Colin; Fass, Deborah

    2012-01-01

    Protein stability, assembly, localization, and regulation often depend on formation of disulfide cross-links between cysteine side chains. Enzymes known as sulfhydryl oxidases catalyze de novo disulfide formation and initiate intra- and intermolecular dithiol/disulfide relays to deliver the disulfides to substrate proteins1,2. Quiescin sulfhydryl oxidase (QSOX) is a unique, multi-domain disulfide catalyst that is localized primarily to the Golgi apparatus and secreted fluids3 and has attracted attention due to its over-production in tumors4,5. In addition to its physiological importance, QSOX is a mechanistically intriguing enzyme, encompassing functions typically carried out by a series of proteins in other disulfide formation pathways. How disulfides are relayed through the multiple redox-active sites of QSOX and whether there is a functional benefit to concatenating these sites on a single polypeptide are open questions. We determined the first crystal structure of an intact QSOX enzyme, derived from a trypanosome parasite. Notably, sequential sites in the disulfide relay were found more than 40 Å apart in this structure, too far for direct disulfide transfer. To resolve this puzzle, we trapped and crystallized an intermediate in the disulfide hand-off, which showed a 165° domain rotation relative to the original structure, bringing the two active sites within disulfide bonding distance. The comparable structure of a mammalian QSOX enzyme, also presented herein, reveals additional biochemical features that facilitate disulfide transfer in metazoan orthologs. Finally, we quantified the contribution of concatenation to QSOX activity, providing general lessons for the understanding of multi-domain enzymes and the design of novel catalytic relays. PMID:22801504

  18. Spatial filter system as an optical relay line

    DOEpatents

    Hunt, John T.; Renard, Paul A.

    1979-01-01

    A system consisting of a set of spatial filters that are used to optically relay a laser beam from one position to a downstream position with minimal nonlinear phase distortion and beam intensity variation. The use of the device will result in a reduction of deleterious beam self-focusing and produce a significant increase in neutron yield from the implosion of targets caused by their irradiation with multi-beam glass laser systems.

  19. Tracking and Data Relay Satellite System (TDRSS) frequency plan

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The functions of the Tracking and Data Relay Satellite System (TDRSS) are discussed. The primary purpose of the system is to transmit signals to and receive signals from earth orbiting user spacecraft, and provide data from which user spacecraft ephemerides can be calculated. The system configuration is described and illustrated. The frequency plan is analyzed to show the frequency coverage and the signal handling capability of the system. The characteristics of the components of the system are tabulated.

  20. Advanced Relay Design and Technology for Energy-Efficient Electronics

    DTIC Science & Technology

    2011-07-07

    4.3.2.2. Monotonicity Analysis vs. Finite - Element -Method Analysis .......................... 53 4.3.3. Summary of Design Optimization Study... film thickness. The movable structure is gradually buckled upward from its anchors toward its geometric center (it appears like an open umbrella...pull-in mode (with a TCONTACT-to-TACT ratio of 0.7 to 0.8) [25]. To validate the new relay design, Finite - Element -Method (FEM) analysis was performed

  1. Science Hybrid Orbiter and Lunar Relay (SCHOLR) Architecture and Design

    NASA Technical Reports Server (NTRS)

    Trase, Kathryn K.; Barch, Rachel A.; Chaney, Ryan E.; Coulter, Rachel A.; Gao, Hui; Huynh, David P.; Iaconis, Nicholas A.; MacMillan, Todd S.; Pitner, Gregory M.; Schwab, Devin T.

    2011-01-01

    Considered both a stepping-stone to deep space and a key to unlocking the mysteries of planetary formation, the Moon offers a unique opportunity for scientific study. Robotic precursor missions are being developed to improve technology and enable new approaches to exploration. Robots, lunar landers, and satellites play significant roles in advancing science and technologies, offering close range and in-situ observations. Science and exploration data gathered from these nodes and a lunar science satellite is intended to support future human expeditions and facilitate future utilization of lunar resources. To attain a global view of lunar science, the nodes will be distributed over the lunar surface, including locations on the far side of the Moon. Given that nodes on the lunar far side do not have direct line-of-sight for Earth communications, the planned presence of such nodes creates the need for a lunar communications relay satellite. Since the communications relay capability would only be required for a small portion of the satellite s orbit, it may be possible to include communication relay components on a science spacecraft. Furthermore, an integrated satellite has the potential to reduce lunar surface mission costs. A SCience Hybrid Orbiter and Lunar Relay (SCHOLR) is proposed to accomplish scientific goals while also supporting the communications needs of landers on the far side of the Moon. User needs and design drivers for the system were derived from the anticipated needs of future robotic and lander missions. Based on these drivers and user requirements, accommodations for communications payload aboard a science spacecraft were developed. A team of interns identified and compared possible SCHOLR architectures. The final SCHOLR architecture was analyzed in terms of orbiter lifetime, lunar surface coverage, size, mass, power, and communications data rates. This paper presents the driving requirements, operational concept, and architecture views for SCHOLR

  2. Mars Express Forward Link Capabilities for the Mars Relay Operations Service (MaROS)

    NASA Technical Reports Server (NTRS)

    Allard, Daniel A.; Wallick, Michael N.; Gladden, Roy E.; Wang, Paul

    2012-01-01

    This software provides a new capability for landed Mars assets to perform forward link relay through the Mars Express (MEX) European Union orbital spacecraft. It solves the problem of standardizing the relay interface between lander missions and MEX. The Mars Operations Relay Service (MaROS) is intended as a central point for relay planning and post-pass analysis for all Mars landed and orbital assets. Through the first two phases of implementation, MaROS supports relay coordination through the Odyssey orbiter and the Mars Reconnaissance Orbiter (MRO). With this new software, MaROS now fully integrates the Mars Express spacecraft into the relay picture. This new software generates and manages a new set of file formats that allows for relay request to MEX for forward and return link relay, including the parameters specific to MEX. Existing MEX relay planning interactions were performed via email exchanges and point-to-point file transfers. By integrating MEX into MaROS, all transactions are managed by a centralized service for tracking and analysis. Additionally, all lander missions have a single, shared interface with MEX and do not have to integrate on a mission-by mission basis. Relay is a critical element of Mars lander data management. Landed assets depend largely upon orbital relay for data delivery, which can be impacted by the availability and health of each orbiter in the network. At any time, an issue may occur to prevent relay. For this reason, it is imperative that all possible orbital assets be integrated into the overall relay picture.

  3. Spacecraft Data and Relay Management using Delay Tolerant Networking

    NASA Technical Reports Server (NTRS)

    Torgerson, J. Leigh; Schoolcraft, Joshua B.; Pang, Jackson N; Segui, John S; Jennings, Esther H.; Krupiarz, Christopher J.

    2006-01-01

    NASA's demonstration of the successful transmission of relay data through the orbiting Mars Odyssey, Mars Global Surveyor, and Mars Express by the Mars Exploration Rovers has shown not only the benefit of using a relay satellite for multiple landed assets in a deep space environment but also the benefit of international standards for such architecture. As NASA begins the quest defined in the Vision for Exploration with robotic and manned missions to the Moon, continues its study of Mars, and is joined in these endeavors by countries world-wide, landed assets transmitting data through relay satellites will be crucial for completing mission objectives. However, this method of delivery of data will result in increased complexity in routing and prioritization of data transmission as the number of missions increases. Also, there is currently no standard method among organizations conducting such missions to return these data sets to Earth given a complex environment. One possibility for establishing such a standard is for mission designers to deploy protocols which fall under the umbrella of Delay Tolerant Networking (DTN). These developing standards include the Bundle Protocol (BP) which provides a standard, secure, store and forward mechanism designed for high latency and asymmetric communication links and the Licklider Transmission Protocol (LTP) which is used to provide a reliable deep space link transmission service.

  4. A cooperative MAC protocol with error-aware relay selection for wireless ad hoc networks

    NASA Astrophysics Data System (ADS)

    Liu, Shanzhi; Liu, Kai; Wang, Rui; Fang, Ruochen; Liu, Feng

    2017-01-01

    To solve performance degradation caused by channel fading, we propose a cooperative MAC protocol with error-aware relay selection for wireless ad hoc networks in this paper. In the protocol, the transmission error of data packet caused by channel fading are considered in order to achieve the best cooperative gain in the poor quality channel. In the relay selection process, potential relay nodes satisfying corresponding requirement can compete to sever as final relay node by means of priority selection and collision resolution process. Finally, simulation results show that the proposed protocol outperforms other protocol in terms of packet error rate and the saturation throughput.

  5. A computer package for teaching relay coordination and loop based network solution

    SciTech Connect

    Goswami, S.K.; Basu, S.K. . Electrical Engineering Dept.)

    1994-05-01

    This paper reports the development of a relay coordination package specially designed as a teaching aid. Fault studies required for relay coordination has been performed by using a newly developed loop impedance matrix. This new method of forming loop impedance matrix is particularly suitable for multiple fault studies environment as required in relay coordination. A simple topology searching technique has been used to find all loops of the network. This package simultaneously serves the purpose of teaching relay coordination, loop analysis technique and the method of topology searching.

  6. Differential network coding for two-way relay networks with massive arrays

    NASA Astrophysics Data System (ADS)

    Fang, Zhaoxi; Shao, Pengfei; Zheng, Wen; Pang, Zeping

    2016-10-01

    In this paper, we propose a low-complexity differential transmission scheme for a two-way relay network (TWRN) with two sources and one relay node, where each source is equipped with a single antenna, while the relay node is equipped with a large number of antennas. In the proposed scheme, no channel state information (CSI) is required at each source node for signal detection. It is shown that as the number of relay antennas becomes large, the received signal at each source node includes the desired signal only. Numerical results are presented to demonstrate the bit-to-error rate (BER) performance of the proposed scheme.

  7. Formulas for predicting the dynamic performance of ROCOF relays for embedded generation applications

    SciTech Connect

    Vieira, J.C. M.; Freitas, Walmir; Huang, Zhenyu; Xu, Wilsun; Morelato, A.

    2006-07-13

    A set of formulas directly predict the performance of rate-of-change-of-frequency (ROCOF) relays used to detect islanding of embedded synchronous generators. The formulas are analytically derived from the dynamic model of the generator and relay. Dynamic simulation results obtained using a representative distribution system confirm the validity and accuracy. The formulas presented are a useful tool for protection engineers; they can be used, for example, to assess the effectiveness of anti-islanding schemes based on ROCOF relays, or to assist the selection of relay settings, significantly reducing the number of repeated dynamic simulations necessary to carry out such studies.

  8. AC resistance measuring instrument

    DOEpatents

    Hof, P.J.

    1983-10-04

    An auto-ranging AC resistance measuring instrument for remote measurement of the resistance of an electrical device or circuit connected to the instrument includes a signal generator which generates an AC excitation signal for application to a load, including the device and the transmission line, a monitoring circuit which provides a digitally encoded signal representing the voltage across the load, and a microprocessor which operates under program control to provide an auto-ranging function by which range resistance is connected in circuit with the load to limit the load voltage to an acceptable range for the instrument, and an auto-compensating function by which compensating capacitance is connected in shunt with the range resistance to compensate for the effects of line capacitance. After the auto-ranging and auto-compensation functions are complete, the microprocessor calculates the resistance of the load from the selected range resistance, the excitation signal, and the load voltage signal, and displays of the measured resistance on a digital display of the instrument. 8 figs.

  9. AC Resistance measuring instrument

    DOEpatents

    Hof, Peter J.

    1983-01-01

    An auto-ranging AC resistance measuring instrument for remote measurement of the resistance of an electrical device or circuit connected to the instrument includes a signal generator which generates an AC excitation signal for application to a load, including the device and the transmission line, a monitoring circuit which provides a digitally encoded signal representing the voltage across the load, and a microprocessor which operates under program control to provide an auto-ranging function by which range resistance is connected in circuit with the load to limit the load voltage to an acceptable range for the instrument, and an auto-compensating function by which compensating capacitance is connected in shunt with the range resistance to compensate for the effects of line capacitance. After the auto-ranging and auto-compensation functions are complete, the microprocessor calculates the resistance of the load from the selected range resistance, the excitation signal, and the load voltage signal, and displays of the measured resistance on a digital display of the instrument.

  10. AC Optimal Power Flow

    SciTech Connect

    2016-10-04

    In this work, we have implemented and developed the simulation software to implement the mathematical model of an AC Optimal Power Flow (OPF) problem. The objective function is to minimize the total cost of generation subject to constraints of node power balance (both real and reactive) and line power flow limits (MW, MVAr, and MVA). We have currently implemented the polar coordinate version of the problem. In the present work, we have used the optimization solver, Knitro (proprietary and not included in this software) to solve the problem and we have kept option for both the native numerical derivative evaluation (working satisfactorily now) as well as for analytical formulas corresponding to the derivatives being provided to Knitro (currently, in the debugging stage). Since the AC OPF is a highly non-convex optimization problem, we have also kept the option for a multistart solution. All of these can be decided by the user during run-time in an interactive manner. The software has been developed in C++ programming language, running with GCC compiler on a Linux machine. We have tested for satisfactory results against Matpower for the IEEE 14 bus system.

  11. Identification of /sup 233/Ac

    SciTech Connect

    Chu, Y.Y.; Zhou, M.L.

    1983-09-01

    We report in this paper identification of the new isotope /sup 233/Ac. Uranium targets were irradiated with 28 GeV protons; after rapid retrieval of the target and separation of actinium from thorium, /sup 233/Ac was allowed to decay into the known /sup 233/Th daughter. Exhaustive chemical purification was employed to permit the identification of /sup 233/Th via its characteristic ..gamma.. radiations. The half-life derived for /sup 233/Ac from several experiments is 2.3 +- 0.3 min. The production cross section for /sup 233/Ac is 100 ..mu..b.

  12. Privacy Preserving Quantum Anonymous Transmission via Entanglement Relay

    PubMed Central

    Yang, Wei; Huang, Liusheng; Song, Fang

    2016-01-01

    Anonymous transmission is an interesting and crucial issue in computer communication area, which plays a supplementary role to data privacy. In this paper, we put forward a privacy preserving quantum anonymous transmission protocol based on entanglement relay, which constructs anonymous entanglement from EPR pairs instead of multi-particle entangled state, e.g. GHZ state. Our protocol achieves both sender anonymity and receiver anonymity against an active adversary and tolerates any number of corrupt participants. Meanwhile, our protocol obtains an improvement in efficiency compared to quantum schemes in previous literature. PMID:27247078

  13. Privacy Preserving Quantum Anonymous Transmission via Entanglement Relay

    NASA Astrophysics Data System (ADS)

    Yang, Wei; Huang, Liusheng; Song, Fang

    2016-06-01

    Anonymous transmission is an interesting and crucial issue in computer communication area, which plays a supplementary role to data privacy. In this paper, we put forward a privacy preserving quantum anonymous transmission protocol based on entanglement relay, which constructs anonymous entanglement from EPR pairs instead of multi-particle entangled state, e.g. GHZ state. Our protocol achieves both sender anonymity and receiver anonymity against an active adversary and tolerates any number of corrupt participants. Meanwhile, our protocol obtains an improvement in efficiency compared to quantum schemes in previous literature.

  14. Coordination procedure for radio relay and communication satellite services

    NASA Technical Reports Server (NTRS)

    Eckerman, J.

    1973-01-01

    A global rain rate statistic model is used to link microwave propagation statistics to measurable rain statistics in order to develop international telecommunication site criteria for radio relay and communication satellite services that minimize interference between receivers and transmitters. This rain coordination procedure utilizes a rain storm cell size, a statistical description of the rainfall rate within the cell valid for most of the earth's surface, approximations between Raleigh scatter and constancy of precipitation with altitude, and an analytic relation between radar reflectivity and rain rate.

  15. Fabricating and using a micromachined magnetostatic relay or switch

    NASA Technical Reports Server (NTRS)

    Tai, Yu-Chong (Inventor); Wright, John A. (Inventor)

    2001-01-01

    A micromachined magnetostatic relay or switch includes a springing beam on which a magnetic actuation plate is formed. The springing beam also includes an electrically conductive contact. In the presence of a magnetic field, the magnetic material causes the springing beam to bend, moving the electrically conductive contact either toward or away from another contact, and thus creating either an electrical short-circuit or an electrical open-circuit. The switch is fabricated from silicon substrates and is particularly useful in forming a MEMs commutation and control circuit for a miniaturized DC motor.

  16. Implementing Strategic Planning Capabilities Within the Mars Relay Operations Service

    NASA Technical Reports Server (NTRS)

    Hy, Franklin

    2011-01-01

    Throughout this development and deployment process we have followed a few guiding principles: (1) Ensure ubiquitous access through ReSTful and web interfaces; (2) Design a system that is mission and even planet agnostic so that future missions may be added with little hassle, and the system itself may be redeployed for other planetary relay networks; (3) Accept constant input and feedback between mission operators and the development team to ensure that there is a useful product that may be used for years to come.

  17. MGS and Odyssey - relay satellites for the MER mission

    NASA Technical Reports Server (NTRS)

    Esposito, Pasquale B.; Bhat, R.; Demeak, S.; Ardalan, S.; Breeden, J.; Helfrich, C.; Jefferson, D.; Stauch, J.

    2004-01-01

    Both Mars Global Surveyor (MGS) and Odyssey are currently in low altitude, nearly circular and highly inclined orbits about Mars. Thus, they are available adn compartible to serve as relay satellites for the Mars Exploration Rovers (MER) mission. Consequently, the MER project developed requirements for MGS to be overhead for MER-A (Spirit) at Gusev crater, at maximum elevation, mudway between lander separation and initial touchdown; in time, this was specified as 01/04/04. 04:24:55 UTC/SCET with a 30 sec tolerance.

  18. Design analysis tracking and data relay satellite simulation system

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The design and development of the equipment necessary to simulate the S-band multiple access link between user spacecraft, the Tracking and Data Relay Satellite, and a ground control terminal are discussed. The core of the S-band multiple access concept is the use of an Adaptive Ground Implemented Phased Array. The array contains thirty channels and provides the multiplexing and demultiplexing equipment required to demonstrate the ground implemented beam forming feature. The system provided will make it possible to demonstrate the performance of a desired user and ten interfering sources attempting to pass data through the multiple access system.

  19. Relay discovery and selection for large-scale P2P streaming.

    PubMed

    Zhang, Chengwei; Wang, Angela Yunxian; Hei, Xiaojun

    2017-01-01

    In peer-to-peer networks, application relays have been commonly used to provide various networking services. The service performance often improves significantly if a relay is selected appropriately based on its network location. In this paper, we studied the location-aware relay discovery and selection problem for large-scale P2P streaming networks. In these large-scale and dynamic overlays, it incurs significant communication and computation cost to discover a sufficiently large relay candidate set and further to select one relay with good performance. The network location can be measured directly or indirectly with the tradeoffs between timeliness, overhead and accuracy. Based on a measurement study and the associated error analysis, we demonstrate that indirect measurements, such as King and Internet Coordinate Systems (ICS), can only achieve a coarse estimation of peers' network location and those methods based on pure indirect measurements cannot lead to a good relay selection. We also demonstrate that there exists significant error amplification of the commonly used "best-out-of-K" selection methodology using three RTT data sets publicly available. We propose a two-phase approach to achieve efficient relay discovery and accurate relay selection. Indirect measurements are used to narrow down a small number of high-quality relay candidates and the final relay selection is refined based on direct probing. This two-phase approach enjoys an efficient implementation using the Distributed-Hash-Table (DHT). When the DHT is constructed, the node keys carry the location information and they are generated scalably using indirect measurements, such as the ICS coordinates. The relay discovery is achieved efficiently utilizing the DHT-based search. We evaluated various aspects of this DHT-based approach, including the DHT indexing procedure, key generation under peer churn and message costs.

  20. Digital ac monitor

    DOEpatents

    Hart, George W.; Kern, Jr., Edward C.

    1987-06-09

    An apparatus and method is provided for monitoring a plurality of analog ac circuits by sampling the voltage and current waveform in each circuit at predetermined intervals, converting the analog current and voltage samples to digital format, storing the digitized current and voltage samples and using the stored digitized current and voltage samples to calculate a variety of electrical parameters; some of which are derived from the stored samples. The non-derived quantities are repeatedly calculated and stored over many separate cycles then averaged. The derived quantities are then calculated at the end of an averaging period. This produces a more accurate reading, especially when averaging over a period in which the power varies over a wide dynamic range. Frequency is measured by timing three cycles of the voltage waveform using the upward zero crossover point as a starting point for a digital timer.

  1. Digital ac monitor

    DOEpatents

    Hart, G.W.; Kern, E.C. Jr.

    1987-06-09

    An apparatus and method is provided for monitoring a plurality of analog ac circuits by sampling the voltage and current waveform in each circuit at predetermined intervals, converting the analog current and voltage samples to digital format, storing the digitized current and voltage samples and using the stored digitized current and voltage samples to calculate a variety of electrical parameters; some of which are derived from the stored samples. The non-derived quantities are repeatedly calculated and stored over many separate cycles then averaged. The derived quantities are then calculated at the end of an averaging period. This produces a more accurate reading, especially when averaging over a period in which the power varies over a wide dynamic range. Frequency is measured by timing three cycles of the voltage waveform using the upward zero crossover point as a starting point for a digital timer. 24 figs.

  2. Cooling Floor AC Systems

    NASA Astrophysics Data System (ADS)

    Jun, Lu; Hao, Ding; Hong, Zhang; Ce, Gao Dian

    The present HVAC equipments for the residential buildings in the Hot-summer-and-Cold-winter climate region are still at a high energy consuming level. So that the high efficiency HVAC system is an urgently need for achieving the preset government energy saving goal. With its advantage of highly sanitary, highly comfortable and uniform of temperature field, the hot-water resource floor radiation heating system has been widely accepted. This paper has put forward a new way in air-conditioning, which combines the fresh-air supply unit and such floor radiation system for the dehumidification and cooling in summer or heating in winter. By analyze its advantages and limitations, we found that this so called Cooling/ Heating Floor AC System can improve the IAQ of residential building while keep high efficiency quality. We also recommend a methodology for the HVAC system designing, which will ensure the reduction of energy cost of users.

  3. Automated ac galvanomagnetic measurement system

    NASA Technical Reports Server (NTRS)

    Szofran, F. R.; Espy, P. N.

    1985-01-01

    An automated, ac galvanomagnetic measurement system is described. Hall or van der Pauw measurements in the temperature range 10-300 K can be made at a preselected magnetic field without operator attendance. Procedures to validate sample installation and correct operation of other system functions, such as magnetic field and thermometry, are included. Advantages of ac measurements are discussed.

  4. Tracking and data relay satellite system configuration and tradeoff study, part 1. Volume 3: Telecommunications service system

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The results of the telecommunications subsystem analysis are presented. The relay system requirements and constraints, interference analysis, frequency selection, modulation and coding analysis, and the performance analysis of the relay system are included.

  5. Considerations for an Earth Relay Satellite with RF and Optical Trunklines

    NASA Technical Reports Server (NTRS)

    Israel, David J.

    2016-01-01

    Support for user platforms through the use of optical links to geosynchronous relay spacecraft are expected to be part of the future space communications architecture. The European Data Relay Satellite System (EDRS) has its first node, EDRS-A, in orbit. The EDRS architecture includes space-to-space optical links with a Ka-Band feeder link or trunkline. NASA's Laser Communications Relay Demonstration (LCRD) mission, originally baselined to support a space-to-space optical link relayed with an optical trunkline, has added an Radio Frequency (RF) trunkline. The use of an RF trunkline avoids the outages suffered by an optical trunkline due to clouds, but an RF trunkline will be bandwidth limited. A space relay architecture with both RF and optical trunklines could relay critical realtime data, while also providing a high data volume capacity. This paper considers the relay user scenarios that could be supported, and the implications to the space relay system and operations. System trades such as the amount of onboard processing and storage required, the use of link layer switching vs. network layer routing, and the use of Delay/Disruption Tolerant Networking (DTN) are discussed.

  6. Development of Autonomous Optimal Cooperative Control in Relay Rover Configured Small Unmanned Aerial Systems

    DTIC Science & Technology

    2013-03-01

    integrated into ground control software that takes telemetry data (the current position of the ground station , rover UAV, and relay UAV) to determine...where to navigate the relay aircraft for optimal communication signal strength. The ground station operator flies the rover aircraft in the extended line...

  7. 75 FR 41863 - Structure and Practices of the Video Relay Service Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-19

    ... COMMISSION Structure and Practices of the Video Relay Service Program AGENCY: Federal Communications Commission. ACTION: Notice. SUMMARY: In this document, the Commission takes a fresh look at its video relay.... SUPPLEMENTARY INFORMATION: This is a summary of the Commission's Structure and Practices of the Video...

  8. 47 CFR 64.6040 - Rates for Telecommunications Relay Service (TRS) calling.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 3 2014-10-01 2014-10-01 false Rates for Telecommunications Relay Service (TRS) calling. 64.6040 Section 64.6040 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON....6040 Rates for Telecommunications Relay Service (TRS) calling. No Provider shall levy or collect...

  9. 76 FR 59269 - Structure and Practices of the Video Relay Service Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-26

    ... COMMISSION 47 CFR Part 64 Structure and Practices of the Video Relay Service Program AGENCY: Federal..., the information collection associated with the Commission's Structure and Practices of the Video Relay... effective date of these rule sections. See, In the Matter of Structure and Practices of the Video...

  10. 76 FR 47476 - Structure and Practices of the Video Relay Service Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-05

    ... COMMISSION 47 CFR Part 64 Structure and Practices of the Video Relay Service Program AGENCY: Federal... requiring that Internet-based Telecommunications Relay Service (iTRS) providers certify, under penalty of... . SUPPLEMENTARY INFORMATION: This is a summary of the Commission's Structure and Practices of the Video...

  11. Coding, modulation, and relays for deep space communication Mars Rovers Case Study

    NASA Technical Reports Server (NTRS)

    Statman, Joseph I.; Edwards, Charles D.

    2004-01-01

    This paper presents the communications challenges for the MER mission, the use of DSN and MER tools to maximize the science return, and the application of standards-based relays to the problem. To date, more than 90% of the data returned from MER has been returned via relays, not direct-to-Earath (DTE).

  12. 47 CFR 64.606 - VRS and IP Relay provider and TRS program certification.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 3 2010-10-01 2010-10-01 false VRS and IP Relay provider and TRS program... CARRIER SERVICES (CONTINUED) MISCELLANEOUS RULES RELATING TO COMMON CARRIERS Telecommunications Relay Services and Related Customer Premises Equipment for Persons With Disabilities § 64.606 VRS and IP...

  13. The Baton Problem: Physics and the 4 x 100 M Relay

    ERIC Educational Resources Information Center

    Harris, Frank

    2012-01-01

    Success in any relay race depends on the speeds achieved by the individual runners and the successful handover of the baton from each runner to the next. Choosing top sprinters is the easy part but there are many ways for the passing of the baton to go wrong. In this article, the knowledge and judgement required by the coach for a relay team are…

  14. 78 FR 21929 - Transmission Relay Loadability Reliability Standard; Notice of Compliance Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-12

    ... Federal Energy Regulatory Commission Transmission Relay Loadability Reliability Standard; Notice of... utilities in three Interconnections. \\1\\ Transmission Relay Loadability Reliability Standard, Order No. 733... ] 61,127 (2011); clarified, Order No. 733-B, 136 FERC ] 61,185 (2011). \\2\\ Transmission...

  15. 75 FR 51735 - Structure and Practices of the Video Relay Service Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-23

    ...; FCC 10-88] Structure and Practices of the Video Relay Service Program AGENCY: Federal Communications... ways to amend its rules to detect and prevent fraud and misuse in the provision of Video Relay Service... changes in order to deter the billing of illegitimate minutes to the Interstate Telecommunications...

  16. 78 FR 28633 - TE Connectivity, a Subsidiary of Tyco Electronics Corporation, Relay Products Business Unit...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-15

    ... Employment and Training Administration TE Connectivity, a Subsidiary of Tyco Electronics Corporation, Relay... Assistance on March 12, 2013, applicable to workers of TE Connectivity, a subsidiary of Tyco Electronics... Connectivity, a subsidiary of Tyco Electronics Corporation, Relay Products Business Unit. The Department...

  17. Polar On-Line Acquisition Relay and Transmission System (POLARATS)

    SciTech Connect

    Yuracko, K.

    2004-07-15

    POLARATS (Polar On-Line Acquisition Relay And Transmission System) is being developed by YAHSGS LLC (YAHSGS) and Oak Ridge National Laboratory (ORNL) to provide remote, unattended monitoring of environmental parameters under harsh environmental conditions. In particular, instrumental design and engineering is oriented towards protection of human health in the Arctic, and with the additional goal of advancing Arctic education and research. POLARATS will obtain and transmit environmental data from hardened monitoring devices deployed in locations important to understanding atmospheric and aquatic pollutant migration as it is biomagnified in Arctic food chains. An Internet- and personal computer (PC)-based educational module will provide real time sensor data, on-line educational content, and will be integrated with workbooks and textbooks for use in middle and high school science programs. The educational elements of POLARATS include an Internet-based educational module that will instruct students in the use of the data and how those data fit into changing Arctic environments and food chains. POLARATS will: (1) Enable students, members of the community, and scientific researchers to monitor local environmental conditions in real time over the Internet; and (2) Provide additional educational benefits through integration with middle- and high-school science curricula. Information will be relayed from POLARATS devices to classrooms and libraries along with custom-designed POLARATS teaching materials that will be integrated into existing curricula to enhance the educational benefits realized from the information obtained.

  18. Detecting relay attacks on RFID communication systems using quantum bits

    NASA Astrophysics Data System (ADS)

    Jannati, Hoda; Ardeshir-Larijani, Ebrahim

    2016-11-01

    RFID systems became widespread in variety of applications because of their simplicity in manufacturing and usability. In the province of critical infrastructure protection, RFID systems are usually employed to identify and track people, objects and vehicles that enter restricted areas. The most important vulnerability which is prevalent among all protocols employed in RFID systems is against relay attacks. Until now, to protect RFID systems against this kind of attack, the only approach is the utilization of distance-bounding protocols which are not applicable over low-cost devices such as RFID passive tags. This work presents a novel technique using emerging quantum technologies to detect relay attacks on RFID systems. Recently, it is demonstrated that quantum key distribution (QKD) can be implemented in a client-server scheme where client only requires an on-chip polarization rotator that may be integrated into a handheld device. Now we present our technique for a tag-reader scenario which needs similar resources as the mentioned QKD scheme. We argue that our technique requires less resources and provides lower probability of false alarm for the system, compared with distance-bounding protocols, and may pave the way to enhance the security of current RFID systems.

  19. Coded Cooperation for Multiway Relaying in Wireless Sensor Networks.

    PubMed

    Si, Zhongwei; Ma, Junyang; Thobaben, Ragnar

    2015-06-29

    Wireless sensor networks have been considered as an enabling technology for constructing smart cities. One important feature of wireless sensor networks is that the sensor nodes collaborate in some manner for communications. In this manuscript, we focus on the model of multiway relaying with full data exchange where each user wants to transmit and receive data to and from all other users in the network. We derive the capacity region for this specific model and propose a coding strategy through coset encoding. To obtain good performance with practical codes, we choose spatially-coupled LDPC (SC-LDPC) codes for the coded cooperation. In particular, for the message broadcasting from the relay, we construct multi-edge-type (MET) SC-LDPC codes by repeatedly applying coset encoding. Due to the capacity-achieving property of the SC-LDPC codes, we prove that the capacity region can theoretically be achieved by the proposed MET SC-LDPC codes. Numerical results with finite node degrees are provided, which show that the achievable rates approach the boundary of the capacity region in both binary erasure channels and additive white Gaussian channels.

  20. Phoenix Mars Scout UHF Relay-Only Operations

    NASA Technical Reports Server (NTRS)

    Lewicki, Christopher A.; Krajewski, Joel; Ilott, Peter; Dates, Jason

    2006-01-01

    The Phoenix Mars Scout Lander will launch in August 2007 and land on the northern plains of Mars in May of 2008. In a departure from traditional planetary surface mission operations, it will have no direct-to-Earth communications capability and will rely entirely on Mars-orbiting relays in order to facilitate command and control as well as the return of science and engineering data. The Mars Exploration Rover missions have demonstrated the robust data-return capability using this architecture, and also have demonstrated the capability of using this method for command and control. The Phoenix mission will take the next step and incorporate this as the sole communications link. Operations for 90 Sols will need to work within the constraints of Odyssey and Mars Reconnaissance Orbiter communications availability, anomalies must be diagnosed and responded to through an intermediary and on-board fault responses must be tolerant to loss of a relay. These and other issues pose interesting challenges and changes in paradigm for traditional space operations and spacecraft architecture, and the approach proposed for the Phoenix mission is detailed herein.

  1. Three Generations of Tracking and Data Relay Satellite (TDRS) Spacecraft

    NASA Technical Reports Server (NTRS)

    Zaleski, Ron

    2016-01-01

    The current Tracking and Data Relay Satellite configuration consists of nine in-orbit satellites (four first generation, three second generation and two third generation satellites) globally distributed in geosynchronous orbit to provide near continuous data relay service to missions like Hubble Space Telescope and the International Space Station. The 1st generation spacecraft were designed by TRW/Northrop Grumman with their launches of the five spacecraft ranging from 1983 through 1995. The 2nd and 3rd generation spacecraft were designed by Boeing with their launches ranging 2000 - 2002 and 2013 - 2017 respectively. TDRS-3 is now 27 years on orbit, continues to be a capable asset for the TDRS constellation. Lack of need for inclination control combined with large fuel reserves and redundancy on critical elements provides spacecraft that operate well past design life, all of which contributes to expanded TDRS constellation support capabilities. All spacecraft generations have issues. Significant issues will be summarized with the focus on the Boeing related problems. Degradations and failures are continually assessed and provide the foundation for yearly updates to spacecraft reliability models, constellation service projections and deorbit plans (in order to meet NASAs mandate of limiting orbital debris). Even when accounting for degradations and failures, the life expectancy for the Boeing delivered 2nd generation TDRS-8, 9 10 TDRS are anticipated to be 25+ years.

  2. Mars Relay Spacecraft: A Low-Cost Approach

    NASA Technical Reports Server (NTRS)

    SvitekT, .; King, J.; Fulton, R.; McOmber, R.; Hastrup, R.; Miller, A.

    1995-01-01

    The next phase of Mars exploration will utilize numerous globally distributed small low-cost devices including landers penetrators microrovers and balloons. Direct-to-Earth communications links if required for these landers will drive the lander design for two reasons: a) mass and complexity needed for a steerable high-gain antenna and b) power requirements for a high-power amplifier (i.e. solar panel and battery mass). Total mass of the direct link hardware for several recent small-lander designs exceeded the mass of the scientific payload. Alternatively if communications are via a Mars-orbiting relay spacecraft resource requirements for the local UHF communication link are comparatively trivial: a simple whip antenna and less than 1 watt power. Clearly using a Mars relay spacecraft (MRS) is the preferred option if the MRS mission can be accomplished in an affordable and robust way. Our paper describes a point design for such a mission launched in the s001 or 2003 opportunity.

  3. UHF Relay Antenna Measurements on Phoenix Mars Lander Mockup

    NASA Technical Reports Server (NTRS)

    Ilott, Peter; Harrel, Jefferson; Arnold, Bradford; Bliznyuk, Natalia; Nielsen, Rick; Dawson, David; McGee, Jodi

    2006-01-01

    The Phoenix Lander, a NASA Discovery mission which lands on Mars in the spring of 2008, will rely entirely on UHF relay links between it and Mars orbiting assets, (Odyssey and Mars Reconnaissance Orbiter (MRO)), to communicate with the Earth. As with the Mars Exploration Rover (MER) relay system, non directional antennas will be used to provide roughly emispherical coverage of the Martian sky. Phoenix lander deck object pattern interference and obscuration are significant, and needed to be quantified to answer system level design and operations questions. This paper describes the measurement campaign carried out at the SPAWAR (Space and Naval Warfare Research) Systems Center San Diego (SSC-SD) hemispherical antenna range, using a Phoenix deck mockup and engineering model antennas. One goal of the measurements was to evaluate two analysis tools, the time domain CST, and the moment method WIPL-D software packages. These would subsequently be used to provide pattern analysis for configurations that would be difficult and expensive to model and test on Earth.

  4. Public Understanding of Chemistry, ACS National Meeting

    NASA Astrophysics Data System (ADS)

    Gettys, Nancy S.

    2000-06-01

    Three public events for area school-aged children were held on Saturday, March 25, 2000, prior to the opening of the 219th National Meeting of the American Chemical Society. All took place at the Moscone Convention Center in downtown San Francisco. The photographs tell the story: the programs were successful and a good time was had by all. Readers may be encouraged to try these ideas in their own area. If so, the local organizers of Carver Kidvention have additional information at www.scvacs.org/Carver/index.html or contact Howard Peters (Santa Clara Valley Section, ACS), peters4pa@aol.com. Additional photos of the Kidvention event may also be seen as supplemental material.

  5. Sequential control by speed drive for ac motor

    NASA Astrophysics Data System (ADS)

    Barsoum, Nader

    2012-11-01

    The speed drive for ac motor is widely used in the industrial field to allow direct control for the speed and torque without any feedback from the motor shaft. By using the ABB ACS800 speed drive unit, the speed and torque can be controlled using sequential control method. Sequential control is one of the application control method provided in the ABB ACS800 Drive, where a set of events or action performed in a particular order one after the other to control the speed and torque of the ac motor. It was claimed that sequential control method is using the preset seven constant speeds being provided in ABB ACS800 drive to control the speed and torque in a continuous and sequential manner. The characteristics and features of controlling the speed and torque using sequential control method can be investigated by observing the graphs and curves plotted which are obtained from the practical result. Sequential control can run either in the Direct Torque Control (DTC) or Scalar motor control mode. By using sequential control method, the ABB ACS800 drive can be programmed to run the motor automatically according to the time setting of the seven preset constant speeds. Besides, the intention of this project is to generate a new form of the experimental set up.

  6. Multiple Retinal Axons Converge onto Relay Cells in the Adult Mouse Thalamus.

    PubMed

    Hammer, Sarah; Monavarfeshani, Aboozar; Lemon, Tyler; Su, Jianmin; Fox, Michael Andrew

    2015-09-08

    Activity-dependent refinement of neural circuits is a fundamental principle of neural development. This process has been well studied at retinogeniculate synapses-synapses that form between retinal ganglion cells (RGCs) and relay cells within the dorsal lateral geniculate nucleus. Physiological studies suggest that shortly after birth, inputs from ∼20 RGCs converge onto relay cells. Subsequently, all but just one to two of these inputs are eliminated. Despite widespread acceptance, this notion is at odds with ultrastructural studies showing numerous retinal terminals clustering onto relay cell dendrites in the adult. Here, we explored this discrepancy using brainbow AAVs and serial block face scanning electron microscopy (SBFSEM). Results with both approaches demonstrate that terminals from numerous RGCs cluster onto relay cell dendrites, challenging the notion that only one to two RGCs innervate each relay cell. These findings force us to re-evaluate our understanding of subcortical visual circuitry.

  7. Trophic relay and prey switching - A stomach contents and calorimetric investigation of an ambassid fish and their saltmarsh prey

    NASA Astrophysics Data System (ADS)

    McPhee, Jack J.; Platell, Margaret E.; Schreider, Maria J.

    2015-12-01

    Trophic relay is an ecological model that involves the movement of biomass and energy from vegetation, such as saltmarshes, within estuaries to the open sea via a series of predator-prey relationships. Any potential for trophic relay is therefore affected by water movements within an estuary and by the ability of a predator to "switch" prey in response to fluctuating abundances of those prey. Saltmarsh-dwelling grapsid crabs, which feed on saltmarsh-derived detritus and microphytobenthos, release zoeae into ebbing tides that inundate saltmarshes during spring-tide cycles within tidally-dominated estuaries, such as Brisbane Water Estuary, therefore providing an opportunity to examine whether prey-switching and/or trophic relay may occur in fish that feed on those zoeae (such as the highly abundant estuarine ambassid, Ambassis jacksoniensis). This model was examined by sampling A. jacksoniensis near saltmarshes in a large, temperate south-eastern Australian estuary during flood and ebb tides on days of saltmarsh inundation and non-inundation over four spring-tide events in 2012. Stomach fullnesses of A. jacksoniensis were generally highest during ebb tides on days of saltmarsh inundation, implying that feeding was most marked at these times. Caridean decapods dominated diets during flood tides and on days of no saltmarsh inundation, while crab zoeae dominated diets during ebb tides and on days of inundation, suggesting that, when saltmarsh-derived zoeae became abundant, A. jacksoniensis switched to feeding on those prey. Three potential zooplankton prey (calanoid copepods, caridean decapods and crab zoeae) did not differ calorimetrically, indicating that switching of prey by A. jacksoniensis is not directly related to their preying on energetically greater prey, but reflects opportunistic feeding on more abundant and/or less elusive prey. As A. jacksoniensis is able to switch prey from estuarine caridean decapods to saltmarsh-derived crab zoeae, this very abundant

  8. 77 FR 75894 - Telecommunications Relay Services and Speech-to-Speech Services for Individuals With Hearing and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-26

    ...] Telecommunications Relay Services and Speech-to-Speech Services for Individuals With Hearing and Speech Disabilities... numbers associated with Internet-based Telecommunications Relay Service (iTRS). For the reasons set forth.... No party opposed Sorenson's Petition, and one party--Hamilton Relay--filed in support....

  9. EMTP transient modeling of a distance relay and a comparison with EMTP laboratory testing. [ElectroMagnetics Transient Program

    SciTech Connect

    Wilson, R.E. ); Nordstrom, J.M. )

    1993-07-01

    This paper reports on a method to test the transient performance of a sampled-data relay. A model of one measuring unit of a digital relay was created on a personal computer. The simulations are compared with laboratory results obtained by applying digitally generated waveforms to the actual relay. Computer modelling of the digital relay is done within the Models version of the Transient Analysis of Control System (TACS) subsection of the ElectroMagnetics Transient Program (EMTP). The input filter, analog to digital converter, Fourier fundamental frequency detector, and the relay measuring principle of one digital microprocessor based relay are modeled. The modeling of these components within an EMTP environment represents new work. An actual 115 Kv 150 mile long transmission line was simulated using the EMTP. The faults simulated on the transmission line were applied both to the digital model of the relay and the actual relay. The physical testing used the Bonneville Power Administration (BPA) Relay Evaluation System (RES). Results from the digital relay simulation are compared with results from an actual relay. The educational value of observing relay waveforms at various stages within the simulation is discussed.

  10. 76 FR 44326 - Telecommunications Relay Services and Speech-to-Speech Services for Individuals With Hearing and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-25

    ... COMMISSION Telecommunications Relay Services and Speech-to-Speech Services for Individuals With Hearing and Speech Disabilities; Structure and Practices of the Video Relay Service Program AGENCY: Federal... extends the current tiered, per-minute video relay service (``VRS'') compensation rates, and adopts...

  11. Layoff Handling Still Lags ACS Standards.

    ERIC Educational Resources Information Center

    Chemical and Engineering News, 1981

    1981-01-01

    Reviews termination procedures of professional chemists and the compliance of these terminations to the American Chemical Society's (ACS's) Professional Employment Guidelines. Provides the ACS guidelines. (DS)

  12. AC photovoltaic module magnetic fields

    SciTech Connect

    Jennings, C.; Chang, G.J.; Reyes, A.B.; Whitaker, C.M.

    1997-12-31

    Implementation of alternating current (AC) photovoltaic (PV) modules, particularly for distributed applications such as PV rooftops and facades, may be slowed by public concern about electric and magnetic fields (EMF). This paper documents magnetic field measurements on an AC PV module, complementing EMF research on direct-current PV modules conducted by PG and E in 1993. Although not comprehensive, the PV EMF data indicate that 60 Hz magnetic fields (the EMF type of greatest public concern) from PV modules are comparable to, or significantly less than, those from household appliances. Given the present EMF research knowledge, AC PV module EMF may not merit considerable concern.

  13. An airborne meteorological data collection system using satellite relay (ASDAR)

    NASA Technical Reports Server (NTRS)

    Bagwell, J. W.; Lindow, B. G.

    1978-01-01

    The National Aeronautics and Space Administration (NASA) has developed an airborne data acquisition and communication system for the National Oceanic and Atmospheric Administration (NOAA). This system known as ASDAR, the Aircraft to Satellite Data Relay, consists of a microprocessor based controller, time clock, transmitter and antenna. Together they acquire meteorological and position information from existing aircraft systems on B-747 aircraft, convert and format these, and transmit them to the ground via the GOES meteorological satellite series. The development and application of the ASDAR system is described with emphasis on unique features. Performance to date is exceptional, providing horizon-to-horizon coverage of aircraft flights. The data collected is of high quality and is considered a valuable addition to the data base from which NOAA generates its weather forecasts.

  14. Long distance quantum teleportation in a quantum relay configuration.

    PubMed

    de Riedmatten, H; Marcikic, I; Tittel, W; Zbinden, H; Collins, D; Gisin, N

    2004-01-30

    A long distance quantum teleportation experiment with a fiber-delayed Bell state measurement (BSM) is reported. The source creating the qubits to be teleported and the source creating the necessary entangled state are connected to the beam splitter realizing the BSM by two 2 km long optical fibers. In addition, the teleported qubits are analyzed after 2.2 km of optical fiber, in another laboratory separated by 55 m. Time-bin qubits carried by photons at 1310 nm are teleported onto photons at 1550 nm. The fidelity is of 77%, above the maximal value obtainable without entanglement. This is the first realization of an elementary quantum relay over significant distances, which will allow an increase in the range of quantum communication and quantum key distribution.

  15. A Calcium-Relay Mechanism in Vertebrate Phototransduction

    PubMed Central

    2013-01-01

    Calcium-signaling in cells requires a fine-tuned system of calcium-transport proteins involving ion channels, exchangers, and ion-pumps but also calcium-sensor proteins and their targets. Thus, control of physiological responses very often depends on incremental changes of the cytoplasmic calcium concentration, which are sensed by calcium-binding proteins and are further transmitted to specific target proteins. This Review will focus on calcium-signaling in vertebrate photoreceptor cells, where recent physiological and biochemical data indicate that a subset of neuronal calcium sensor proteins named guanylate cyclase-activating proteins (GCAPs) operate in a calcium-relay system, namely, to make gradual responses to small changes in calcium. We will further integrate this mechanism in an existing computational model of phototransduction showing that it is consistent and compatible with the dynamics that are characteristic for the precise operation of the phototransduction pathways. PMID:23472635

  16. Relay telescope for high power laser alignment system

    DOEpatents

    Dane, C. Brent; Hackel, Lloyd; Harris, Fritz B.

    2006-09-19

    A laser system includes an optical path having an intracavity relay telescope with a telescope focal point for imaging an output of the gain medium between an image location at or near the gain medium and an image location at or near an output coupler for the laser system. A kinematic mount is provided within a vacuum chamber, and adapted to secure beam baffles near the telescope focal point. An access port on the vacuum chamber is adapted for allowing insertion and removal of the beam baffles. A first baffle formed using an alignment pinhole aperture is used during alignment of the laser system. A second tapered baffle replaces the alignment aperture during operation and acts as a far-field baffle in which off angle beams strike the baffle a grazing angle of incidence, reducing fluence levels at the impact areas.

  17. The mammillary bodies and memory: more than a hippocampal relay

    PubMed Central

    Vann, Seralynne D.; Nelson, Andrew J.D.

    2015-01-01

    Although the mammillary bodies were one of the first neural structures to be implicated in memory, it has long been assumed that their main function was to act primarily as a hippocampal relay, passing information on to the anterior thalamic nuclei and from there to the cingulate cortex. This view not only afforded the mammillary bodies no independent role in memory, it also neglected the potential significance of other, nonhippocampal, inputs to the mammillary bodies. Recent advances have transformed the picture, revealing that projections from the tegmental nuclei of Gudden, and not the hippocampal formation, are critical for sustaining mammillary body function. By uncovering a role for the mammillary bodies that is independent of its subicular inputs, this work signals the need to consider a wider network of structures that form the neural bases of episodic memory. PMID:26072239

  18. Optical design of the post-focal relay of MAORY

    NASA Astrophysics Data System (ADS)

    Lombini, M.; De Rosa, A.; Ciliegi, P.; Cortecchia, F.; Diolaiti, E.; Patti, Mauro; Bonaglia, M.; Busoni, L.; De Caprio, V.; Esposito, S.; Feautrier, P.; Rabou, P.; Riva, M.; Stadler, E.

    2016-08-01

    The Multi Conjugate Adaptive Optics RelaY (MAORY) for the European Extremely Large Telescope is planned to be located on the straight-through port of the telescope Nasmyth platform and shall re-image the telescope focal plane to a wide field camera (MICADO) and a possible future second instrument. By means of natural and artificial (laser) reference sources for wavefront sensing, and of deformable mirrors for wavefront correction, MAORY shall be able to compensate the wavefront disturbances affecting the scientific observations, achieving high Strehl ratio and high sky coverage. A trade-off study among different design options has been carried out addressing optical performance at the exit ports (wave front error, field distortion, throughput), structure stability, interface constraints (mass, size, location and accessibility of the two client instruments), and the overall adaptive optics performance. We discuss the baseline configuration of the opto-mechanical design.

  19. Design and assessment of microlenslet-array relay optics.

    PubMed

    Shaoulov, Vesselin; Rolland, Jannick P

    2003-12-01

    Recent progress in micro-optics fabrication and optical modeling software opens the opportunity to investigate how microlenslet-array-based compact relay systems can be designed and assessed. We present various optical configurations that include an appropriate baffle computation to eliminate ghost images, followed by an analysis of image quality. The investigation shows the existing trade-off between compactness of the system and a tiling effect observed in the corresponding image, an effect we refer to as lensletization. To yield meaningful optical modeling results, we provide insight into ray-tracing optimization while ensuring a sufficient signal-to-noise ratio. The results show that, given no discernable lensletization, the most compact configuration to image gray-scale images is the 5f-based system. Finally, simulations of the imaging of gray scale and color bitmaps through microlenslet arrays are demonstrated for the first time to our knowledge.

  20. GSFC network operations with Tracking and Data Relay Satellites

    NASA Astrophysics Data System (ADS)

    Spearing, R.; Perreten, D. E.

    The Tracking and Data Relay Satellite System (TDRSS) Network (TN) has been developed to provide services to all NASA User spacecraft in near-earth orbits. Three inter-relating entities will provide these services. The TN has been transformed from a network continuously changing to meet User specific requirements to a network which is flexible to meet future needs without significant changes in operational concepts. Attention is given to the evolution of the TN network, the TN capabilities-space segment, forward link services, tracking services, return link services, the three basic capabilities, single access services, multiple access services, simulation services, the White Sands Ground Terminal, the NASA communications network, and the network control center.

  1. The design and evaluation of grazing incidence relay optics

    NASA Technical Reports Server (NTRS)

    Davis, John M.; Chase, R. C.; Silk, J. K.; Krieger, A. S.

    1989-01-01

    X-ray astronomy, both solar and celestial, has many needs for high spatial resolution observations which have to be performed with electronic detectors. If the resolution is not to be detector limited, plate scales in excess of 25 microns arc/sec, corresponding to focal lengths greater than 5 m, are required. In situations where the physical size is restricted, the problem can be solved by the use of grazing incidence relay optics. A system was developed which employs externally polished hyperboloid-hyperboloid surfaces to be used in conjunction with a Wolter-Schwarzschild primary. The secondary is located in front of the primary focus and provides a magnification of 4, while the system has a plate scale of 28 microns arc/sec and a length of 1.9 m. The design, tolerance specification, fabrication and performance at visible and X-ray wavelengths of this optical system are described.

  2. Automation of servicibility of radio-relay station equipment

    NASA Astrophysics Data System (ADS)

    Uryev, A. G.; Mishkin, Y. I.; Itkis, G. Y.

    1985-03-01

    Automation of the serviceability of radio relay station equipment must ensure central gathering and primary processing of reliable instrument reading with subsequent display on the control panel, detection and recording of failures soon enough, advance enough warning based on analysis of detertioration symptoms, and correct remote measurement of equipment performance parameters. Such an inspection will minimize transmission losses while reducing nonproductive time and labor spent on documentation and measurement. A multichannel automated inspection system for this purpose should operate by a parallel rather than sequential procedure. Digital data processing is more expedient in this case than analog method and, therefore, analog to digital converters are required. Spepcial normal, above limit and below limit test signals provide means of self-inspection, to which must be added adequate interference immunization, stabilization, and standby power supply. Use of a microcomputer permits overall refinement and expansion of the inspection system while it minimizes though not completely eliminates dependence on subjective judgment.

  3. Tensile-stressed microelectromechanical apparatus and microelectromechanical relay formed therefrom

    DOEpatents

    Fleming, James G.

    2008-03-04

    A microelectromechanical (MEM) apparatus is disclosed which includes a shuttle suspended above a substrate by two or more sets of tensile-stressed beams which are operatively connected to the shuttle and which can comprise tungsten or a silicon nitride/polysilicon composite structure. Initially, the tensile stress in each set of beams is balanced. However, the tensile stress can be unbalanced by heating one or more of the sets of beams; and this can be used to move the shuttle over a distance of up to several tens of microns. The MEM apparatus can be used to form a MEM relay having relatively high contact and opening forces, and with or without a latching capability.

  4. Glutamate receptor functions in sensory relay in the thalamus.

    PubMed Central

    Salt, T E

    2002-01-01

    It is known that glutamate is a major excitatory transmitter of sensory and cortical afferents to the thalamus. These actions are mediated via several distinct receptors with postsynaptic excitatory effects predominantly mediated by ionotropic receptors of the alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) and N-methyl-D-aspartate varieties (NMDA). However, there are also other kinds of glutamate receptor present in the thalamus, notably the metabotropic and kainate types, and these may have more complex or subtle roles in sensory transmission. This paper describes recent electrophysiological experiments done in vitro and in vivo which aim to determine how the metabotropic and kainate receptor types can influence transmission through the sensory thalamic relay. A particular focus will be how such mechanisms might operate under physiological conditions. PMID:12626010

  5. Excitatory actions of peptide histidine isoleucine on thalamic relay neurons.

    PubMed

    Lee, Sang-Hun; Cox, Charles L

    2008-12-01

    Peptide histidine isoleucine (PHI) and vasoactive intestinal peptide (VIP) are neuropeptides synthesized from a common precursor, prepro-VIP, and share structural similarity and biological functions in many systems. Within the central nervous system and peripheral tissues, PHI and VIP have overlapping distribution. PHI-mediated functions are generally via activation of VIP receptors; however, the potency and affinity of PHI for VIP receptors are significantly lower than VIP. In addition, several studies suggest distinct PHI receptors that are independent of VIP receptors. PHI receptors have been cloned and characterized in fish, but their existence in mammals is still unknown. This study focuses on the functional role of PHI in the thalamus because of the localization of both PHI and VIP receptors in this brain region. Using extracellular multiple-unit recording techniques, we found that PHI strongly attenuated the slow intrathalamic rhythmic activity. Using intracellular recording techniques, we found that PHI selectively depolarized thalamic relay neurons via an enhancement of the hyperpolarization-activated mixed cation current, Ih. Further, the actions of PHI were occluded by VIP and dopamine, indicating these modulators converge onto a common mechanism. In contrast to previous work, we found that PHI was more potent than VIP in producing excitatory actions on thalamic neurons. We next used the transgenic mice lacking a specific VIP receptor, VPAC2, to identify its possible role in PHI-mediated actions in the thalamus. PHI depolarized all relay neurons tested from wild-type mice (VPAC2(+/+)); however, in knockout mice (VPAC2(-/-)), PHI produced no change in membrane potential in all neurons tested. Our findings indicate that excitatory actions of PHI are mediated by VPAC2 receptors, not by its own PHI receptors and the excitatory actions of PHI clearly attenuate intrathalamic rhythmic activities, and likely influence information transfer through thalamocortical

  6. Wireless Relay Selection in Pocket Switched Networks Based on Spatial Regularity of Human Mobility †

    PubMed Central

    Huang, Jianhui; Cheng, Xiuzhen; Bi, Jingping; Chen, Biao

    2016-01-01

    Pocket switched networks (PSNs) take advantage of human mobility to deliver data. Investigations on real-world trace data indicate that human mobility shows an obvious spatial regularity: a human being usually visits a few places at high frequencies. These most frequently visited places form the home of a node, which is exploited in this paper to design two HomE based Relay selectiOn (HERO) algorithms. Both algorithms input single data copy into the network at any time. In the basic HERO, only the first node encountered by the source and whose home overlaps a destination’s home is selected as a relay while the enhanced HERO keeps finding more optimal relay that visits the destination’s home with higher probability. The two proposed algorithms only require the relays to exchange the information of their home and/or the visiting frequencies to their home when two nodes meet. As a result, the information update is reduced and there is no global status information that needs to be maintained. This causes light loads on relays because of the low communication cost and storage requirements. Additionally, only simple operations are needed in the two proposed algorithms, resulting in little computation overhead at relays. At last, a theoretical analysis is performed on some key metrics and then the real-world based simulations indicate that the two HERO algorithms are efficient and effective through employing only one or a few relays. PMID:26797609

  7. The Physical Layer Security Experiments of Cooperative Communication System with Different Relay Behaviors.

    PubMed

    Su, Yishan; Han, Guangyao; Fu, Xiaomei; Xu, Naishen; Jin, Zhigang

    2017-04-06

    Physical layer security is an attractive security mechanism, which exploits the randomness characteristics of wireless transmission channel to achieve security. However, it is hampered by the limitation of the channel condition that the main channel must be better than the eavesdropper channel. To alleviate the limitation, cooperative communication is introduced. Few studies have investigated the physical layer security of the relay transmission model. In this paper, we performed some experiments to evaluate the physical layer security of a cooperative communication system, with a relay operating in decode-and-forward (DF) cooperative mode, selfish and malicious behavior in real non-ideal transmission environment. Security performance is evaluated in terms of the probability of non-zero secrecy capacity. Experiments showed some different results compared to theoretical simulation: (1) to achieve the maximum secrecy capacity, the optimal relay power according to the experiments result is larger than that of ideal theoretical results under both cooperative and selfish behavior relay; (2) the relay in malicious behavior who forwards noise to deteriorate the main channel may deteriorate the eavesdropper channel more seriously than the main channel; (3) the optimal relay positions under cooperative and selfish behavior relay cases are both located near the destination because of non-ideal transmission.

  8. Cell speed, persistence and information transmission during signal relay and collective migration.

    PubMed

    McCann, Colin P; Kriebel, Paul W; Parent, Carole A; Losert, Wolfgang

    2010-05-15

    Collective migration is a key feature of the social amoebae Dictyostelium discoideum, where the binding of chemoattractants leads to the production and secretion of additional chemoattractant and the relay of the signal to neighboring cells. This then guides cells to migrate collectively in a head-to-tail fashion. We used mutants that were defective in signal relay to elucidate which quantitative metrics of cell migration are most strongly affected by signal relay and collective motion. We show that neither signal relay nor collective motion markedly impact the speed of cell migration. Cells maintained a preferred overall direction of motion for several minutes with similar persistence, regardless of whether or not they were attracted to moving neighbors, moving collectively in contact with their neighbors, or simply following a fixed exogenous signal. We quantitatively establish that signal relay not only increases the number of cells that respond to a chemotactic signal, but most remarkably, also transmits information about the location of the source accurately over large distances, independently of the strength of the exogenous signal. We envision that signal relay has a similar key role in the migration of a variety of chemotaxing mammalian cells that can relay chemoattractant signals.

  9. Wireless Relay Selection in Pocket Switched Networks Based on Spatial Regularity of Human Mobility.

    PubMed

    Huang, Jianhui; Cheng, Xiuzhen; Bi, Jingping; Chen, Biao

    2016-01-18

    Pocket switched networks (PSNs) take advantage of human mobility to deliver data. Investigations on real-world trace data indicate that human mobility shows an obvious spatial regularity: a human being usually visits a few places at high frequencies. These most frequently visited places form the home of a node, which is exploited in this paper to design two HomE based Relay selectiOn (HERO) algorithms. Both algorithms input single data copy into the network at any time. In the basic HERO, only the first node encountered by the source and whose home overlaps a destination's home is selected as a relay while the enhanced HERO keeps finding more optimal relay that visits the destination's home with higher probability. The two proposed algorithms only require the relays to exchange the information of their home and/or the visiting frequencies to their home when two nodes meet. As a result, the information update is reduced and there is no global status information that needs to be maintained. This causes light loads on relays because of the low communication cost and storage requirements. Additionally, only simple operations are needed in the two proposed algorithms, resulting in little computation overhead at relays. At last, a theoretical analysis is performed on some key metrics and then the real-world based simulations indicate that the two HERO algorithms are efficient and effective through employing only one or a few relays.

  10. The Relay/Converter Interface Influences Hydrolysis of ATP by Skeletal Muscle Myosin II.

    PubMed

    Bloemink, Marieke J; Melkani, Girish C; Bernstein, Sanford I; Geeves, Michael A

    2016-01-22

    The interface between relay and converter domain of muscle myosin is critical for optimal myosin performance. Using Drosophila melanogaster indirect flight muscle S1, we performed a kinetic analysis of the effect of mutations in the converter and relay domain. Introduction of a mutation (R759E) in the converter domain inhibits the steady-state ATPase of myosin S1, whereas an additional mutation in the relay domain (N509K) is able to restore the ATPase toward wild-type values. The R759E S1 construct showed little effect on most steps of the actomyosin ATPase cycle. The exception was a 25-30% reduction in the rate constant of the hydrolysis step, the step coupled to the cross-bridge recovery stroke that involves a change in conformation at the relay/converter domain interface. Significantly, the double mutant restored the hydrolysis step to values similar to the wild-type myosin. Modeling the relay/converter interface suggests a possible interaction between converter residue 759 and relay residue 509 in the actin-detached conformation, which is lost in R759E but is restored in N509K/R759E. This detailed kinetic analysis of Drosophila myosin carrying the R759E mutation shows that the interface between the relay loop and converter domain is important for fine-tuning myosin kinetics, in particular ATP binding and hydrolysis.

  11. Contingency Support Simulation for the Tracking and Data Relay Satellite System (TDRSS)

    NASA Technical Reports Server (NTRS)

    Dykes, Andy; Dunham, Joan; Ward, Douglas T.; Robertson, Mika; Nesbit, Gary

    2007-01-01

    In March 2006, the Tracking and Data Relay Satellite (TDRS)-3 experienced an unexpected thrusting event, which caused significant changes to its orbit. Recovery from this anomaly was protracted, raising concerns during the Independent Review Team (IRT) investigation of the anomaly regarding the contingency response readiness. The simulations and readiness exercises discussed in this paper were part of the response to the IRT concerns. This paper explains the various levels of simulation needed to enhance the proficiency of the Flight Dynamics Facility (FDF) and supporting elements in recovery from a TDRS contingency situation. The main emergency to address is when a TDRS has experienced uncommanded, unreported, or misreported thrusting, causing a ground station to lose the ability to acquire the spacecraft, as happened in 2006. The following levels of simulation are proposed: 1) Tests that would be performed by the individual support sites to verify that internal procedures and tools are in place and up to date; 2) Tabletop simulations that would involve all of the key support sites talking through their respective operating procedures to ensure that proper notifications are made and communications links are established; and 3) Comprehensive simulations that would be infrequent, but realistic, involving data exchanges between ground sites and voice and electronic communications among the supporting elements.

  12. Mars Interoperability 2008-2015: Options for Relay Orbiter Support to Mars Bound Assets

    NASA Technical Reports Server (NTRS)

    Kazz, Greg J.; Greenberg, Edward

    2008-01-01

    The current relay orbiter infrastructure at Mars, in support of the user assets presently at Mars and those scheduled for the 2008 to 2015 time frame, only have a need to store-and-forward the returned data collected by an asset to Earth as a single non-prioritized data file. In the forward direction, the relay orbiters are only required to relay the forward link data, i.e., command sequences, software and configuration information assembled on the ground, to the Asset. There are currently no requirements for status/control messages or files to be sent in the return direction from an Asset to an application located on the Relay, nor are there requirements in the forward direction to send status/control messages or files originating on a Relay to an Asset. In addition there are currently no networking requirements at Mars where data originally sent by an Asset is to be delivered to another user asset. However, we foresee the day when standard services for 1) on-board file prioritization of user asset data by a Relay, 2) control/status message transfer between assets and a Relay, and 3) networking between assets i.e., Asset to Asset message/file transfer via a Relay will be required. Each of these services will require the Relay to be capable of understanding the data type and routing needs of the user asset data and be capable of processing it for these purposes. This paper will focus on the innovative enhancements required to the existing communications infrastructure at Mars to enable these future services.

  13. Incorporating multiple energy relay dyes in liquid dye-sensitized solar cells.

    PubMed

    Yum, Jun-Ho; Hardin, Brian E; Hoke, Eric T; Baranoff, Etienne; Zakeeruddin, Shaik M; Nazeeruddin, Mohammad K; Torres, Tomas; McGehee, Michael D; Grätzel, Michael

    2011-02-25

    Panchromatic response is essential to increase the light-harvesting efficiency in solar conversion systems. Herein we show increased light harvesting from using multiple energy relay dyes inside dye-sensitized solar cells. Additional photoresponse from 400-590 nm matching the optical window of the zinc phthalocyanine sensitizer was observed due to Förster resonance energy transfer (FRET) from the two energy relay dyes to the sensitizing dye. The complementary absorption spectra of the energy relay dyes and high excitation transfer efficiencies result in a 35% increase in photovoltaic performance.

  14. Innovation Relay: Empowering School Nurses to Find New Solutions for Old Problems.

    PubMed

    Maughan, Erin D; Galemore, Cynthia; Mattey, Beth

    2016-09-01

    NASN's 48th Annual School Nurse Conference-Learning, Linking, Leading-included the first ever innovation relay contest. The relay was based on a design developed by the Institute of Healthcare Improvement's Innovation Relay. Participation included 43 contestants from 16 states and one foreign country. Teams were given 24 hours to develop a solution. This article describes the process utilized, the problem introduced, and a brief synopsis of each team's solution. The ongoing purpose of the exercise is to encourage innovation by school nurses as they experience student health-related barriers in the academic setting.

  15. NONLINEAR DIAGNOSTICS USING AC DIPOLES.

    SciTech Connect

    PEGGS,S.

    1999-03-29

    There are three goals in the accurate nonlinear diagnosis of a storage ring. First, the beam must be moved to amplitudes many times the natural beam size. Second, strong and long lasting signals must be generated. Third, the measurement technique should be non-destructive. Conventionally, a single turn kick moves the beam to large amplitudes, and turn-by-turn data are recorded from multiple beam position monitors (BPMs) [1-6]. Unfortunately, tune spread across the beam causes the center of charge beam signal to ''decohere'' on a time scale often less than 100 turns. Filamentation also permanently destroys the beam emittance (in a hadron ring). Thus, the ''strong single turn kick'' technique successfully achieves only one out of the three goals. AC dipole techniques can achieve all three. Adiabatically excited AC dipoles slowly move the beam out to large amplitudes. The coherent signals then recorded last arbitrarily long. The beam maintains its original emittance if the AC dipoles are also turned off adiabatically, ready for further use. The AGS already uses an RF dipole to accelerate polarized proton beams through depolarizing resonances with minimal polarization loss [7]. Similar AC dipoles will be installed in the horizontal and vertical planes of both rings in RHIC [8]. The RHIC AC dipoles will also be used as spin flippers, and to measure linear optical functions [9].

  16. G.E. SLATE SWITCHBOARD WITH RELAYS IN GLINES POWERHOUSE. ALSO NOTE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    G.E. SLATE SWITCHBOARD WITH RELAYS IN GLINES POWERHOUSE. ALSO NOTE 1926 PHONE BOOTH (STILL IN OPERATION). PHOTO BY JET LOWE, HAER, 1995. - Elwha River Hydroelectric System, Glines Hydroelectric Dam & Plant, Port Angeles, Clallam County, WA

  17. Balancing outage performance of primary user and secondary user by relay-assisted primary transmission

    NASA Astrophysics Data System (ADS)

    Zhao, Feng; Sun, Xiangqi; Chen, Hongbin; Bie, Rongfang

    2014-12-01

    In this paper, a cooperative transmission protocol for cognitive radio systems is proposed. In this protocol, the primary system comprises a transmitter (PT), a receiver (PR), and a decode-and-forward relay (Relay), while the secondary system comprises a transmitter (ST) and a receiver (SR). Both the ST and the Relay assist the transmissions of the primary users together. The outage probabilities of the primary system and the secondary system are analyzed and verified through simulations. In order to decrease outage probability of the secondary system, power allocation is performed at the ST. However, it will lead to deterioration of outage performance of the primary system. In order to guarantee outage performance of the primary system, a Relay is employed. Compared with two existing protocols, one without cooperation and the other with cooperation of the secondary system only, the proposed protocol is able to better balance outage performances of the primary system and the secondary system.

  18. Improved BDF Relaying Scheme Using Time Diversity over Atmospheric Turbulence and Misalignment Fading Channels

    PubMed Central

    García-Zambrana, Antonio; Castillo-Vázquez, Carmen; Castillo-Vázquez, Beatriz

    2014-01-01

    A novel bit-detect-and-forward (BDF) relaying scheme based on repetition coding with the relay is proposed, significantly improving the robustness to impairments proper to free-space optical (FSO) communications such as unsuitable alignment between transmitter and receiver as well as fluctuations in the irradiance of the transmitted optical beam due to the atmospheric turbulence. Closed-form asymptotic bit-error-rate (BER) expressions are derived for a 3-way FSO communication setup. Fully exploiting the potential time-diversity available in the relay turbulent channel, a relevant better performance is achieved, showing a greater robustness to the relay location since a high diversity gain is provided regardless of the source-destination link distance. PMID:24587711

  19. Modeling of Protection in Dynamic Simulation Using Generic Relay Models and Settings

    SciTech Connect

    Samaan, Nader A.; Dagle, Jeffery E.; Makarov, Yuri V.; Diao, Ruisheng; Vallem, Mallikarjuna R.; Nguyen, Tony B.; Miller, Laurie E.; Vyakaranam, Bharat; Tuffner, Francis K.; Pai, M. A.; Conto, Jose; Kang, Sun Wook

    2016-07-19

    This paper shows how generic protection relay models available in planning tools can be augmented with settings that are based on NERC standards or best engineering practice. Selected generic relay models in Siemens PSS®E have been used in dynamic simulations in the proposed approach. Undervoltage, overvoltage, underfrequency, and overfrequency relays have been modeled for each generating unit. Distance-relay protection was modeled for transmission system protection. Two types of load-shedding schemes were modeled: underfrequency (frequency-responsive non-firm load shedding) and underfrequency and undervoltage firm load shedding. Several case studies are given to show the impact of protection devices on dynamic simulations. This is useful for simulating cascading outages.

  20. Double- and relay-cropping oilseed and biomass crops for sustainable energy production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Economically and environmentally sustainable bioenergy production requires strategic integration of biofuel crops into modern cropping systems. Double- and relay-cropping can offer a means of increasing production efficiency to boost profits and provide environmental benefits through crop diversific...

  1. Tracking and Delay Relay Satellite System (TDRSS)-LIGHT: a space communications architecture

    NASA Astrophysics Data System (ADS)

    Seery, Bernard D.; Fitzmaurice, Michael W.; Hayden, William L.; Burt, Joseph; Minott, Peter O.; Krainak, Michael A.

    1994-08-01

    There is a growing interest in applying the resources of the Tracking and Data Relay Satellite System (TDRSS) as the primary support capability for future small satellite users. This interest is based on a variety of benefits offered by the TDRSS, and not available with globally-distributed space-ground links. An architecture based on an optical augmentation to the current TDRSS space network is discussed, including a candidate design for the user and relay terminals.

  2. Event Perception.

    PubMed

    Radvansky, Gabriel; Zacks, Jeffrey M

    2011-11-01

    Events are central elements of human experience. Formally, they can be individuated in terms of the entities that compose them, the features of those entities, and the relations amongst entities. Psychologically, representations of events capture their spatiotemporal location, the people and objects involved, and the relations between these elements. Here, we present an account of the nature of psychological representations of events and how they are constructed and updated. Event representations are like images in that they are isomorphic to the situations they represent. However, they are like models or language in that they are constructed of components rather than being holistic. Also, they are partial representations that leave out some elements and abstract others. Representations of individual events are informed by schematic knowledge about general classes of events. Event representations are constructed in a process that segments continuous activity into discrete events. The construction of a series of event representations forms a basis for predicting the future, planning for that future, and imagining alternatives.

  3. Event Perception

    PubMed Central

    Radvansky, Gabriel; Zacks, Jeffrey M.

    2012-01-01

    Events are central elements of human experience. Formally, they can be individuated in terms of the entities that compose them, the features of those entities, and the relations amongst entities. Psychologically, representations of events capture their spatiotemporal location, the people and objects involved, and the relations between these elements. Here, we present an account of the nature of psychological representations of events and how they are constructed and updated. Event representations are like images in that they are isomorphic to the situations they represent. However, they are like models or language in that they are constructed of components rather than being holistic. Also, they are partial representations that leave out some elements and abstract others. Representations of individual events are informed by schematic knowledge about general classes of events. Event representations are constructed in a process that segments continuous activity into discrete events. The construction of a series of event representations forms a basis for predicting the future, planning for that future, and imagining alternatives. PMID:23082236

  4. Development and Testing of a Two-UAV Communication Relay System

    PubMed Central

    Li, Boyang; Jiang, Yifan; Sun, Jingxuan; Cai, Lingfeng; Wen, Chih-Yung

    2016-01-01

    In the development of beyond-line-of-sight (BLOS) Unmanned Aerial Vehicle (UAV) systems, communication between the UAVs and the ground control station (GCS) is of critical importance. The commonly used economical wireless modules are restricted by the short communication range and are easily blocked by obstacles. The use of a communication relay system provides a practical way to solve these problems, improving the performance of UAV communication in BLOS and cross-obstacle operations. In this study, a communication relay system, in which a quadrotor was used to relay radio communication for another quadrotor was developed and tested. First, the UAVs used as the airborne platform were constructed, and the hardware for the communication relay system was selected and built up. Second, a set of software programs and protocol for autonomous mission control, communication relay control, and ground control were developed. Finally, the system was fully integrated into the airborne platform and tested both indoor and in-flight. The Received Signal Strength Indication (RSSI) and noise value in two typical application scenarios were recorded. The test results demonstrated the ability of this system to extend the communication range and build communication over obstacles. This system also shows the feasibility to coordinate multiple UAVs’ communication with the same relay structure. PMID:27754369

  5. Mars Relay Operations Service (MaROS): A Present Service Preparing for the Future

    NASA Technical Reports Server (NTRS)

    Gladden, Roy E.

    2014-01-01

    The Mars Relay Operations Service (MaROS) has been deployed by NASA's Mars Program Office and the Multimission Ground Systems and Services (MGSS) Project into mission operations to aid in the coordination of relay activities at Mars. This live system presents standardized interfaces and a centralized infrastructure to current and future participants in the Mars Relay Network for the purpose of reliably and securely exchanging and storing all relay-related planning and operations data. The initial development of this system leveraged over eight years of experience performing relay operations between the various spacecraft at Mars. Now, four years after its initial deployment, MaROS continues to undergo further refinement to better meet the needs of the Mars Relay Network. The most substantial, recent update was focused on providing capabilities needed by the Mars Science Laboratory project, which landed on Mars in August of 2012. This paper will describe the nature of that update and describe additional features being added to the system to better serve the needs of current and future Mars missions.

  6. Exploiting Outage and Error Probability of Cooperative Incremental Relaying in Underwater Wireless Sensor Networks

    PubMed Central

    Nasir, Hina; Javaid, Nadeem; Sher, Muhammad; Qasim, Umar; Khan, Zahoor Ali; Alrajeh, Nabil; Niaz, Iftikhar Azim

    2016-01-01

    This paper embeds a bi-fold contribution for Underwater Wireless Sensor Networks (UWSNs); performance analysis of incremental relaying in terms of outage and error probability, and based on the analysis proposition of two new cooperative routing protocols. Subject to the first contribution, a three step procedure is carried out; a system model is presented, the number of available relays are determined, and based on cooperative incremental retransmission methodology, closed-form expressions for outage and error probability are derived. Subject to the second contribution, Adaptive Cooperation in Energy (ACE) efficient depth based routing and Enhanced-ACE (E-ACE) are presented. In the proposed model, feedback mechanism indicates success or failure of data transmission. If direct transmission is successful, there is no need for relaying by cooperative relay nodes. In case of failure, all the available relays retransmit the data one by one till the desired signal quality is achieved at destination. Simulation results show that the ACE and E-ACE significantly improves network performance, i.e., throughput, when compared with other incremental relaying protocols like Cooperative Automatic Repeat reQuest (CARQ). E-ACE and ACE achieve 69% and 63% more throughput respectively as compared to CARQ in hard underwater environment. PMID:27420061

  7. Exploiting Outage and Error Probability of Cooperative Incremental Relaying in Underwater Wireless Sensor Networks.

    PubMed

    Nasir, Hina; Javaid, Nadeem; Sher, Muhammad; Qasim, Umar; Khan, Zahoor Ali; Alrajeh, Nabil; Niaz, Iftikhar Azim

    2016-07-12

    This paper embeds a bi-fold contribution for Underwater Wireless Sensor Networks (UWSNs); performance analysis of incremental relaying in terms of outage and error probability, and based on the analysis proposition of two new cooperative routing protocols. Subject to the first contribution, a three step procedure is carried out; a system model is presented, the number of available relays are determined, and based on cooperative incremental retransmission methodology, closed-form expressions for outage and error probability are derived. Subject to the second contribution, Adaptive Cooperation in Energy (ACE) efficient depth based routing and Enhanced-ACE (E-ACE) are presented. In the proposed model, feedback mechanism indicates success or failure of data transmission. If direct transmission is successful, there is no need for relaying by cooperative relay nodes. In case of failure, all the available relays retransmit the data one by one till the desired signal quality is achieved at destination. Simulation results show that the ACE and E-ACE significantly improves network performance, i.e., throughput, when compared with other incremental relaying protocols like Cooperative Automatic Repeat reQuest (CARQ). E-ACE and ACE achieve 69% and 63% more throughput respectively as compared to CARQ in hard underwater environment.

  8. a Distance Protection Strategic Spare Relay for 132/66 kv Overhead Lines

    NASA Astrophysics Data System (ADS)

    Harris, R. T.; Roberts, A. G.; Marks, A.; Phipps, W.

    2010-06-01

    The South African electrical supply utility (Eskom) has been experiencing problems in the field of protection, maintenance and in-service breakdowns which influence the quality of electrical supply to the consumer, an important and integral component of the utility business. As a result, further development of the generic relay, implemented as a strategic spare relay for the replacement of several schemes operating within Eskom's southern region has been initiated. These include the electromechanical, solid state and numerical distance protection relays and scheme failures on the 132/66 kV feeder network. The research considers the development, testing and configuration of the strategic spare relay in terms of software and peripheral hardware for the input and output terminal connections, generic equations and settings, for the purpose of scheme replacements. The various schemes are assessed for stepped distance and permissive intertripping for three and single pole operation. This is done in conjunction with the internal and external circuit diagrams to understand the detailed operation of the scheme and to ensure the effective implementation of the strategic spare relay. The generic relay is configured for the emergency replacement of the various schemes during in-service breakdowns. This constitutes a temporary installation and therefore the downtime of all the distance protection schemes that require replacement, is limited to a minimum.

  9. Performance Analysis of Amplify-and-Forward Systems with Single Relay Selection in Correlated Environments

    PubMed Central

    Nguyen, Binh Van; Kim, Kiseon

    2016-01-01

    In this paper, we consider amplify-and-forward (AnF) cooperative systems under correlated fading environments. We first present a brief overview of existing works on the effect of channel correlations on the system performance. We then focus on our main contribution which is analyzing the outage probability of a multi-AnF-relay system with the best relay selection (BRS) scheme under a condition that two channels of each relay, source-relay and relay-destination channels, are correlated. Using lower and upper bounds on the end-to-end received signal-to-noise ratio (SNR) at the destination, we derive corresponding upper and lower bounds on the system outage probability. We prove that the system can achieve a diversity order (DO) equal to the number of relays. In addition, and importantly, we show that the considered correlation form has a constructive effect on the system performance. In other words, the larger the correlation coefficient, the better system performance. Our analytic results are corroborated by extensive Monte-Carlo simulations. PMID:27626426

  10. Relay cropping as a sustainable approach: problems and opportunities for sustainable crop production.

    PubMed

    Tanveer, Mohsin; Anjum, Shakeel Ahmad; Hussain, Saddam; Cerdà, Artemi; Ashraf, Umair

    2017-03-01

    Climate change, soil degradation, and depletion of natural resources are becoming the most prominent challenges for crop productivity and environmental sustainability in modern agriculture. In the scenario of conventional farming system, limited chances are available to cope with these issues. Relay cropping is a method of multiple cropping where one crop is seeded into standing second crop well before harvesting of second crop. Relay cropping may solve a number of conflicts such as inefficient use of available resources, controversies in sowing time, fertilizer application, and soil degradation. Relay cropping is a complex suite of different resource-efficient technologies, which possesses the capability to improve soil quality, to increase net return, to increase land equivalent ratio, and to control the weeds and pest infestation. The current review emphasized relay cropping as a tool for crop diversification and environmental sustainability with special focus on soil. Briefly, benefits, constraints, and opportunities of relay cropping keeping the goals of higher crop productivity and sustainability have also been discussed in this review. The research and knowledge gap in relay cropping was also highlighted in order to guide the further studies in future.

  11. Development and Testing of a Two-UAV Communication Relay System.

    PubMed

    Li, Boyang; Jiang, Yifan; Sun, Jingxuan; Cai, Lingfeng; Wen, Chih-Yung

    2016-10-13

    In the development of beyond-line-of-sight (BLOS) Unmanned Aerial Vehicle (UAV) systems, communication between the UAVs and the ground control station (GCS) is of critical importance. The commonly used economical wireless modules are restricted by the short communication range and are easily blocked by obstacles. The use of a communication relay system provides a practical way to solve these problems, improving the performance of UAV communication in BLOS and cross-obstacle operations. In this study, a communication relay system, in which a quadrotor was used to relay radio communication for another quadrotor was developed and tested. First, the UAVs used as the airborne platform were constructed, and the hardware for the communication relay system was selected and built up. Second, a set of software programs and protocol for autonomous mission control, communication relay control, and ground control were developed. Finally, the system was fully integrated into the airborne platform and tested both indoor and in-flight. The Received Signal Strength Indication (RSSI) and noise value in two typical application scenarios were recorded. The test results demonstrated the ability of this system to extend the communication range and build communication over obstacles. This system also shows the feasibility to coordinate multiple UAVs' communication with the same relay structure.

  12. Structural dynamics of the myosin relay helix by time-resolved EPR and FRET.

    PubMed

    Agafonov, Roman V; Negrashov, Igor V; Tkachev, Yaroslav V; Blakely, Sarah E; Titus, Margaret A; Thomas, David D; Nesmelov, Yuri E

    2009-12-22

    We have used two complementary time-resolved spectroscopic techniques, dipolar electron-electron resonance and fluorescence resonance energy transfer to determine conformational changes in a single structural element of the myosin motor domain, the relay helix, before and after the recovery stroke. Two double-Cys mutants were labeled with optical probes or spin labels, and interprobe distances were determined. Both methods resolved two distinct structural states of myosin, corresponding to straight and bent conformations of the relay helix. The bent state was occupied only upon nucleotide addition, indicating that relay helix, like the entire myosin head, bends in the recovery stroke. However, saturation of myosin with nucleotide, producing a single biochemical state, did not produce a single structural state. Both straight and bent structural states of the relay helix were occupied when either ATP (ADP.BeF(x)) or ADP.P(i) (ADP.AlF(4)) analogs were bound at the active site. A greater population was found in the bent structural state when the posthydrolysis analog ADP.AlF(4) was bound. We conclude that the bending of the relay helix in the recovery stroke does not require ATP hydrolysis but is favored by it. A narrower interprobe distance distribution shows ordering of the relay helix, despite its bending, during the recovery stroke, providing further insight into the dynamics of this energy-transducing structural transition.

  13. The impact of SFCL and SMES integration on the distance relay

    NASA Astrophysics Data System (ADS)

    Yang, Jun; Zhang, Liling; Wang, Xinpu; Chen, Lei; Chen, Yanxia

    2016-11-01

    The superconducting fault current limiter (SFCL) is an ideal short-circuit fault current limiting device that can limit the fault current without any delay and control the voltage drop of the non-fault line. The superconducting magnetic energy storage (SMES) device can exchange the active and reactive power independently, so it is applied broadly to improve power system stability. With SFCL, the low voltage ride-through capability of SMES can be enhanced as well as its MW and MJ capacities. The distance relay is a key electrical apparatus that will trip circuit breakers to protect electrical devices from short circuit faults. Due to the application of SFCL and SMES integration, the voltage and current in power grid will change accordingly, and the operation characteristic of distance relay may be affected. In this paper, the impact of a bridge-type SFCL and SMES integration on the circle distance relay is studied. And simulation results show that the integration of SFCL and SMES does influence the measured impedance of distance relay, which can lead to mal-operation of the circle distance relay. Furthermore, an improved distance relay is proposed and verified.

  14. Performance Analysis of Amplify-and-Forward Systems with Single Relay Selection in Correlated Environments.

    PubMed

    Van Nguyen, Binh; Kim, Kiseon

    2016-09-11

    In this paper, we consider amplify-and-forward (AnF) cooperative systems under correlated fading environments. We first present a brief overview of existing works on the effect of channel correlations on the system performance. We then focus on our main contribution which is analyzing the outage probability of a multi-AnF-relay system with the best relay selection (BRS) scheme under a condition that two channels of each relay, source-relay and relay-destination channels, are correlated. Using lower and upper bounds on the end-to-end received signal-to-noise ratio (SNR) at the destination, we derive corresponding upper and lower bounds on the system outage probability. We prove that the system can achieve a diversity order (DO) equal to the number of relays. In addition, and importantly, we show that the considered correlation form has a constructive effect on the system performance. In other words, the larger the correlation coefficient, the better system performance. Our analytic results are corroborated by extensive Monte-Carlo simulations.

  15. Enzyme structure captures four cysteines aligned for disulfide relay

    PubMed Central

    Gat, Yair; Vardi-Kilshtain, Alexandra; Grossman, Iris; Major, Dan Thomas; Fass, Deborah

    2014-01-01

    Thioredoxin superfamily proteins introduce disulfide bonds into substrates, catalyze the removal of disulfides, and operate in electron relays. These functions rely on one or more dithiol/disulfide exchange reactions. The flavoenzyme quiescin sulfhydryl oxidase (QSOX), a catalyst of disulfide bond formation with an interdomain electron transfer step in its catalytic cycle, provides a unique opportunity for exploring the structural environment of enzymatic dithiol/disulfide exchange. Wild-type Rattus norvegicus QSOX1 (RnQSOX1) was crystallized in a conformation that juxtaposes the two redox-active di-cysteine motifs in the enzyme, presenting the entire electron-transfer pathway and proton-transfer participants in their native configurations. As such a state cannot generally be enriched and stabilized for analysis, RnQSOX1 gives unprecedented insight into the functional group environments of the four cysteines involved in dithiol/disulfide exchange and provides the framework for analysis of the energetics of electron transfer in the presence of the bound flavin adenine dinucleotide cofactor. Hybrid quantum mechanics/molecular mechanics (QM/MM) free energy simulations based on the X-ray crystal structure suggest that formation of the interdomain disulfide intermediate is highly favorable and secures the flexible enzyme in a state from which further electron transfer via the flavin can occur. PMID:24888638

  16. Smad2 and Smad3 have differential sensitivity in relaying TGFβ signaling and inversely regulate early lineage specification.

    PubMed

    Liu, Ling; Liu, Xu; Ren, Xudong; Tian, Yue; Chen, Zhenyu; Xu, Xiangjie; Du, Yanhua; Jiang, Cizhong; Fang, Yujiang; Liu, Zhongliang; Fan, Beibei; Zhang, Quanbin; Jin, Guohua; Yang, Xiao; Zhang, Xiaoqing

    2016-02-24

    The transforming growth factor beta (TGFβ) related signaling is one of the most important signaling pathways regulating early developmental events. Smad2 and Smad3 are structurally similar and it is mostly considered that they are equally important in mediating TGFβ signals. Here, we show that Smad3 is an insensitive TGFβ transducer as compared with Smad2. Smad3 preferentially localizes within the nucleus and is thus sequestered from membrane signaling. The ability of Smad3 in oligomerization with Smad4 upon agonist stimulation is also impaired given its unique linker region. Smad2 mediated TGFβ signaling plays a crucial role in epiblast development and patterning of three germ layers. However, signaling unrelated nuclear localized Smad3 is dispensable for TGFβ signaling-mediated epiblast specification, but important for early neural development, an event blocked by TGFβ/Smad2 signaling. Both Smad2 and Smad3 bind to the conserved Smads binding element (SBE), but they show nonoverlapped target gene binding specificity and differential transcriptional activity. We conclude that Smad2 and Smad3 possess differential sensitivities in relaying TGFβ signaling and have distinct roles in regulating early developmental events.

  17. Smad2 and Smad3 have differential sensitivity in relaying TGFβ signaling and inversely regulate early lineage specification

    PubMed Central

    Liu, Ling; Liu, Xu; Ren, Xudong; Tian, Yue; Chen, Zhenyu; Xu, Xiangjie; Du, Yanhua; Jiang, Cizhong; Fang, Yujiang; Liu, Zhongliang; Fan, Beibei; Zhang, Quanbin; Jin, Guohua; Yang, Xiao; Zhang, Xiaoqing

    2016-01-01

    The transforming growth factor beta (TGFβ) related signaling is one of the most important signaling pathways regulating early developmental events. Smad2 and Smad3 are structurally similar and it is mostly considered that they are equally important in mediating TGFβ signals. Here, we show that Smad3 is an insensitive TGFβ transducer as compared with Smad2. Smad3 preferentially localizes within the nucleus and is thus sequestered from membrane signaling. The ability of Smad3 in oligomerization with Smad4 upon agonist stimulation is also impaired given its unique linker region. Smad2 mediated TGFβ signaling plays a crucial role in epiblast development and patterning of three germ layers. However, signaling unrelated nuclear localized Smad3 is dispensable for TGFβ signaling-mediated epiblast specification, but important for early neural development, an event blocked by TGFβ/Smad2 signaling. Both Smad2 and Smad3 bind to the conserved Smads binding element (SBE), but they show nonoverlapped target gene binding specificity and differential transcriptional activity. We conclude that Smad2 and Smad3 possess differential sensitivities in relaying TGFβ signaling and have distinct roles in regulating early developmental events. PMID:26905010

  18. Specific binding of Autographa californica M nucleopolyhedrovirus occlusion-derived virus to midgut cells of Heliothis virescens larvae is mediated by products of pif genes Ac119 and Ac022 but not by Ac115.

    PubMed

    Ohkawa, Taro; Washburn, Jan O; Sitapara, Ronika; Sid, Eric; Volkman, Loy E

    2005-12-01

    Per os infectivity factors PIF1 (Ac119) and PIF2 (Ac022), like P74, are essential for oral infection of lepidopteran larval hosts of Autographa californica M nucleopolyhedrovirus (AcMNPV). Here we show that Ac115 also is a PIF (PIF3) and that, unlike PIF1 and PIF2, it does not mediate specific binding of AcMNPV occlusion-derived virus (ODV) to midgut target cells. We used an improved in vivo fluorescence dequenching assay to compare binding, fusion, and competition among control AcMNPV ODV and the ODVs of AcMNPV PIF1, PIF2, and PIF3 deletion mutants. Our results showed that binding and fusion of PIF1 and PIF2 mutants, but not the PIF3 mutant, were both qualitatively and quantitatively different from those of control ODV. Unlike control and PIF3-deficient ODV, an excess of PIF1- or PIF2-deficient ODV failed to compete effectively with control ODV's binding to specific receptors on midgut epithelial cells. Moreover, the levels of PIF1- and PIF2-deficient ODV binding were depressed threefold compared to control levels. Binding, fusion, and competition by PIF3-deficient ODV, however, were all indistinguishable from those of control ODV. These results implicated PIF1 and PIF2 as ODV envelope attachment proteins that mediate specific binding to primary target cells within the midgut. In contrast, PIF3 mediates another unidentified, but critical, early event during primary infection.

  19. ACS from development to operations

    NASA Astrophysics Data System (ADS)

    Caproni, Alessandro; Colomer, Pau; Jeram, Bogdan; Sommer, Heiko; Chiozzi, Gianluca; Mañas, Miguel M.

    2016-08-01

    The ALMA Common Software (ACS), provides the infrastructure of the distributed software system of ALMA and other projects. ACS, built on top of CORBA and Data Distribution Service (DDS) middleware, is based on a Component- Container paradigm and hides the complexity of the middleware allowing the developer to focus on domain specific issues. The transition of the ALMA observatory from construction to operations brings with it that ACS effort focuses primarily on scalability, stability and robustness rather than on new features. The transition came together with a shorter release cycle and a more extensive testing. For scalability, the most problematic area has been the CORBA notification service, used to implement the publisher subscriber pattern because of the asynchronous nature of the paradigm: a lot of effort has been spent to improve its stability and recovery from run time errors. The original bulk data mechanism, implemented using the CORBA Audio/Video Streaming Service, showed its limitations and has been replaced with a more performant and scalable DDS implementation. Operational needs showed soon the difference between releases cycles for Online software (i.e. used during observations) and Offline software, which requires much more frequent releases. This paper attempts to describe the impact the transition from construction to operations had on ACS, the solution adopted so far and a look into future evolution.

  20. Simple Equipment for Imaging AC.

    ERIC Educational Resources Information Center

    Kamata, Masahiro; Anayama, Takayuki

    2003-01-01

    Presents an effective way to demonstrate the difference between direct current and alternating current using red and green LEDs. Describes how to make a tool that shows how an AC voltage changes with time using the afterimage effect of the LEDs. (Author/NB)

  1. Introducing high performance distributed logging service for ACS

    NASA Astrophysics Data System (ADS)

    Avarias, Jorge A.; López, Joao S.; Maureira, Cristián; Sommer, Heiko; Chiozzi, Gianluca

    2010-07-01

    The ALMA Common Software (ACS) is a software framework that provides the infrastructure for the Atacama Large Millimeter Array and other projects. ACS, based on CORBA, offers basic services and common design patterns for distributed software. Every properly built system needs to be able to log status and error information. Logging in a single computer scenario can be as easy as using fprintf statements. However, in a distributed system, it must provide a way to centralize all logging data in a single place without overloading the network nor complicating the applications. ACS provides a complete logging service infrastructure in which every log has an associated priority and timestamp, allowing filtering at different levels of the system (application, service and clients). Currently the ACS logging service uses an implementation of the CORBA Telecom Log Service in a customized way, using only a minimal subset of the features provided by the standard. The most relevant feature used by ACS is the ability to treat the logs as event data that gets distributed over the network in a publisher-subscriber paradigm. For this purpose the CORBA Notification Service, which is resource intensive, is used. On the other hand, the Data Distribution Service (DDS) provides an alternative standard for publisher-subscriber communication for real-time systems, offering better performance and featuring decentralized message processing. The current document describes how the new high performance logging service of ACS has been modeled and developed using DDS, replacing the Telecom Log Service. Benefits and drawbacks are analyzed. A benchmark is presented comparing the differences between the implementations.

  2. Alternative relay domains of Drosophila melanogaster myosin differentially affect ATPase activity, in vitro motility, myofibril structure and muscle function.

    PubMed

    Kronert, William A; Dambacher, Corey M; Knowles, Aileen F; Swank, Douglas M; Bernstein, Sanford I

    2008-06-06

    The relay domain of myosin is hypothesized to function as a communication pathway between the nucleotide-binding site, actin-binding site and the converter domain. In Drosophila melanogaster, a single myosin heavy chain gene encodes three alternative relay domains. Exon 9a encodes the indirect flight muscle isoform (IFI) relay domain, whereas exon 9b encodes one of the embryonic body wall isoform (EMB) relay domains. To gain a better understanding of the function of the relay domain and the differences imparted by the IFI and the EMB versions, we constructed two transgenic Drosophila lines expressing chimeric myosin heavy chains in indirect flight muscles lacking endogenous myosin. One expresses the IFI relay domain in the EMB backbone (EMB-9a), while the second expresses the EMB relay domain in the IFI backbone (IFI-9b). Our studies reveal that the EMB relay domain is functionally equivalent to the IFI relay domain when it is substituted into IFI. Essentially no differences in ATPase activity, actin-sliding velocity, flight ability at room temperature or muscle structure are observed in IFI-9b compared to native IFI. However, when the EMB relay domain is replaced with the IFI relay domain, we find a 50% reduction in actin-activated ATPase activity, a significant increase in actin affinity, abolition of actin sliding, defects in myofibril assembly and rapid degeneration of muscle structure compared to EMB. We hypothesize that altered relay domain conformational changes in EMB-9a impair intramolecular communication with the EMB-specific converter domain. This decreases transition rates involving strongly bound actomyosin states, leading to a reduced ATPase rate and loss of actin motility.

  3. IEEE 802.16J-Relay Fortified Aeromacs Networks; Benefits and Challenges

    NASA Technical Reports Server (NTRS)

    Kamali, Behnam; Apaza, Rafael D.

    2014-01-01

    Aeronautical Mobile Airport Communications System (AeroMACS) is an IEEE 802.16 standard-based (WiMAX) broadband aviation transmission technology, developed to provide safety critical communications coverage for airport surface in support of fixed and mobile ground to ground applications and services. We have previously demonstrated that IEEE 802.16j-amendment-based WiMAX is most feasible for AeroMACS applications. The principal argument in favor of application of IEEE 802.16j technology is the flexible and cost effective extension of radio coverage that is afforded by relay fortified WiMAX networks, with virtually no increase in the power requirements. In this article, following introductory remarks on airport surface communications, WiMAX and AeroMACS; the IEEE 802.16j-based WiMAX technology and multihop relay systems are briefly described. The two modes of relay operation supported by IEEE 802.16j amendment; i.e., transparent (TRS) and non-transparent (NTRS) modes, are discussed in some detail. Advantages and disadvantages of using TRS and NTRS in AeroMACS networks are summarized in a table. Practical issues vis--vis the inclusion of relays in AeroMACS networks are addressed. It is argued that the selection of relay type may affect a number of network parameters. A discussion on specific benefits and challenges of inclusion of relays in AeroMACS networks is provided. The article concludes that in case it is desired or necessary to exclusively employ one type of relay mode for all applications throughout an AeroMACS network, the proper selection would be the non-transparent mode.

  4. Exact outage analysis of the effect of co-channel interference on secured multi-hop relaying networks

    NASA Astrophysics Data System (ADS)

    Quang Nguyen, Sang; Kong, Hyung Yun

    2016-11-01

    In this article, the presence of multi-hop relaying, eavesdropper and co-channel interference (CCI) in the same system model is investigated. Specifically, the effect of CCI on a secured multi-hop relaying network is studied, in which the source communicates with the destination via multi-relay-hopping under the presence of an eavesdropper and CCI at each node. The optimal relay at each cluster is selected to help forward the message from the source to the destination. We apply two relay selection approaches to such a system model, i.e. the optimal relay is chosen based on (1) the maximum channel gain from the transmitter to all relays in the desired cluster and (2) the minimum channel gain from the eavesdropper to all relays in each cluster. For the performance evaluation and comparison, we derived the exact closed form of the secrecy outage probability of the two approaches. That analysis is verified by Monte Carlo simulation. Finally, the effects of the number of hops, the transmit power at the source, relays and the external sources, the distance between the external sources and each node in the system, and the location of the eavesdropper are presented and discussed.

  5. MGS and Odyssey - Relay Satellites for the MER Mission

    NASA Technical Reports Server (NTRS)

    Esposito, Pasquale B.; Bhat, R.; Demcak, S.; Ardakab, S.; Breeden, J.; Helfrich, C.; Jefferson, D.; Stauch, J.

    2004-01-01

    Both Mars Global Surveyor (MGS) and Mars Odyssey are currently in low altitude, nearly circular and highly inclined orbits about Mars. Thus, they are available and compatible to serve as relay satellites for the Mars Exploration Rover (MER) mission. Consequently, the MER project developed requirements for MGS to be overhead, at a specific time with a 30 second tolerance, during the atmospheric entry, descent and landing (EDL) phase of both MER vehicles. The result, after execution of a single orbit synchronization maneuver (OSM) on 10/03/03, 92.4 days or 1130 orbits before Spirit's EDL, was that MGS was over Spirit 8 seconds past the required time. This maneuver, with a delta-velocity of 0.534 m/s, caused the orbital period to change by 3.34 s and resulted in a time-phasing change of 62 min 19 s in order to achieve the EDL overflight. Based on the navigation and execution of an OSM on 01/04/04, MGS was overhead for the Opportunity EDL on 01/25/04,3.5 seconds after the required epoch. Requirements also existed for the Odyssey over-flight of the MER rovers after landing and various equipment deployments had been completed. Thus, these requirements were that Odyssey should rise no earlier than specified times with respect to each of the landing sites. The Odyssey over-flights of both Spirit and Opportunity on sol 1 were equally successful. This paper will present the navigation plan, trajectory propagation accuracy and maneuver execution for the successful MGS and Odyssey over-flights of both the MER rovers.

  6. Reliability of spike and burst firing in thalamocortical relay cells.

    PubMed

    Zeldenrust, Fleur; Chameau, Pascal J P; Wadman, Wytse J

    2013-12-01

    The reliability and precision of the timing of spikes in a spike train is an important aspect of neuronal coding. We investigated reliability in thalamocortical relay (TCR) cells in the acute slice and also in a Morris-Lecar model with several extensions. A frozen Gaussian noise current, superimposed on a DC current, was injected into the TCR cell soma. The neuron responded with spike trains that showed trial-to-trial variability, due to amongst others slow changes in its internal state and the experimental setup. The DC current allowed to bring the neuron in different states, characterized by a well defined membrane voltage (between -80 and -50 mV) and by a specific firing regime that on depolarization gradually shifted from a predominantly bursting regime to a tonic spiking regime. The filtered frozen white noise generated a spike pattern output with a broad spike interval distribution. The coincidence factor and the Hunter and Milton measure were used as reliability measures of the output spike train. In the experimental TCR cell as well as the Morris-Lecar model cell the reliability depends on the shape (steepness) of the current input versus spike frequency output curve. The model also allowed to study the contribution of three relevant ionic membrane currents to reliability: a T-type calcium current, a cation selective h-current and a calcium dependent potassium current in order to allow bursting, investigate the consequences of a more complex current-frequency relation and produce realistic firing rates. The reliability of the output of the TCR cell increases with depolarization. In hyperpolarized states bursts are more reliable than single spikes. The analytically derived relations were capable to predict several of the experimentally recorded spike features.

  7. An overview of the ALMA Common Software (ACS) .

    NASA Astrophysics Data System (ADS)

    Di Marcantonio, P.; Cirami, R.; Caproni, A.; Chiozzi, G.; Jeram, B.; Sommer, H.; Harrington, S.; Zagar, K.; Plesko, M.; Sekoranja, M.

    The ALMA Common Software (ACS) is an application framework designed to provide a common and homogeneous software architecture and infrastructure, spanning the end to end needs of an Astronomical observatory, from the Telescope Control system to high-level data flow management. ACS offers, at the lower level, several basic services needed for object-oriented distributed computing like transparent remote object invocation, object deployment and location, distributed error, alarm handling, logging and events. On top of this it provides an application architecture based on the Component/Container paradigm that fosters sharing and reusing of software components. Although developed for the ALMA project, ACS is now used by several other projects worldwide, among which the Italian Sardinia Radio Telescope (SRT). Besides, there is an active community that shares ideas, concepts and actual software components. Major drivers for this diffusion were the choice of adopting the LGPL public license and the adoption of CORBA, a free but reliable and widely used middleware software. In this paper we present an overview of the main features of ACS, emphasizing in particular the role of INAF-OAT in this project.

  8. The ISC Seismic Event Bibliography

    NASA Astrophysics Data System (ADS)

    Di Giacomo, Domenico; Storchak, Dmitry

    2015-04-01

    The International Seismological Centre (ISC) is a not-for-profit organization operating in the UK for the last 50 years and producing the ISC Bulletin - the definitive worldwide summary of seismic events, both natural and anthropogenic - starting from the beginning of 20th century. Often researchers need to gather information related to specific seismic events for various reasons. To facilitate such task, in 2012 we set up a new database linking earthquakes and other seismic events in the ISC Bulletin to bibliographic records of scientific articles (mostly peer-reviewed journals) that describe those events. Such association allows users of the ISC Event Bibliography (www.isc.ac.uk/event_bibliography/index.php) to run searches for publications via a map-based web interface and, optionally, selecting scientific publications related to either specific events or events in the area of interest. Some of the greatest earthquakes were described in several hundreds of articles published over a period of few years. The journals included in our database are not limited to seismology but bring together a variety of fields in geosciences (e.g., engineering seismology, geodesy and remote sensing, tectonophysics, monitoring research, tsunami, geology, geochemistry, hydrogeology, atmospheric sciences, etc.) making this service useful in multidisciplinary studies. Usually papers dealing with large data set are not included (e.g., papers describing a seismic catalogue). Currently the ISC Event Bibliography includes over 17,000 individual publications from about 500 titles related to over 14,000 events that occurred in last 100+ years. The bibliographic records in the Event Bibliography start in the 1950s, and it is updated as new publications become available.

  9. Similar synapse elimination motifs at successive relays in the same efferent pathway during development in mice

    PubMed Central

    Sheu, Shu-Hsien; Tapia, Juan Carlos; Tsuriel, Shlomo; Lichtman, Jeff W

    2017-01-01

    In many parts of the nervous system, signals pass across multiple synaptic relays on their way to a destination, but little is known about how these relays form and the function they serve. To get some insight into this question we ask how the connectivity patterns are organized at two successive synaptic relays in a simple, cholinergic efferent pathway. We found that the organization at successive relays in the parasympathetic nervous system strongly resemble each other despite the different embryological origin and physiological properties of the pre- and postsynaptic cells. Additionally, we found a similar developmental synaptic pruning and elaboration strategy is used at both sites to generate their adult organizations. The striking parallels in adult innervation and developmental mechanisms at the relays argue that a general strategy is in operation. We discuss why from a functional standpoint this structural organization may amplify central signals while at the same time maintaining positional targeting. DOI: http://dx.doi.org/10.7554/eLife.23193.001 PMID:28157072

  10. Generation of major human excretory and circulating drug metabolites using a hepatocyte relay method.

    PubMed

    Ballard, T Eric; Orozco, Christine C; Obach, R Scott

    2014-05-01

    The prediction of human drug metabolites using in vitro experiments containing human-derived reagents is an important approach in modern drug research; however, this can be challenging for drugs that are slowly metabolized. In this report, we describe the use of a recently developed human hepatocyte relay method for the purpose of predicting human drug metabolite profiles. Five compounds for which in vivo human metabolism data were available were selected for the investigation of this method, and the results were compared with data gathered in hepatocyte suspensions as well as previous data from a micropatterned hepatocyte coculture method. The hepatocyte relay method demonstrated an improved performance (generation of 75% of human in vivo metabolites) for those drugs for which previous methods showed a relatively low rate of success (50% of human in vivo metabolites). Metabolites included those arising from both oxidative and conjugative reactions and metabolites that required sequential reactions. Two 4-hour relays were shown to adequately generate metabolites, and no further benefit was derived from more relays. Overall, it can be concluded that the hepatocyte relay assay method can be successfully used in the generation of relevant human metabolites, even for challenging drugs.

  11. Mapping interactions between myosin relay and converter domains that power muscle function.

    PubMed

    Kronert, William A; Melkani, Girish C; Melkani, Anju; Bernstein, Sanford I

    2014-05-02

    Intramolecular communication within myosin is essential for its function as motor, but the specific amino acid residue interactions required are unexplored within muscle cells. Using Drosophila melanogaster skeletal muscle myosin, we performed a novel in vivo molecular suppression analysis to define the importance of three relay loop amino acid residues (Ile(508), Asn(509), and Asp(511)) in communicating with converter domain residue Arg(759). We found that the N509K relay mutation suppressed defects in myosin ATPase, in vitro motility, myofibril stability, and muscle function associated with the R759E converter mutation. Through molecular modeling, we define a mechanism for this interaction and suggest why the I508K and D511K relay mutations fail to suppress R759E. Interestingly, I508K disabled motor function and myofibril assembly, suggesting that productive relay-converter interaction is essential for both processes. We conclude that the putative relay-converter interaction mediated by myosin residues 509 and 759 is critical for the biochemical and biophysical function of skeletal muscle myosin and the normal ultrastructural and mechanical properties of muscle.

  12. RoCoMAR: robots' controllable mobility aided routing and relay architecture for mobile sensor networks.

    PubMed

    Le, Duc Van; Oh, Hoon; Yoon, Seokhoon

    2013-07-05

    In a practical deployment, mobile sensor network (MSN) suffers from a low performance due to high node mobility, time-varying wireless channel properties, and obstacles between communicating nodes. In order to tackle the problem of low network performance and provide a desired end-to-end data transfer quality, in this paper we propose a novel ad hoc routing and relaying architecture, namely RoCoMAR (Robots' Controllable Mobility Aided Routing) that uses robotic nodes' controllable mobility. RoCoMAR repeatedly performs link reinforcement process with the objective of maximizing the network throughput, in which the link with the lowest quality on the path is identified and replaced with high quality links by placing a robotic node as a relay at an optimal position. The robotic node resigns as a relay if the objective is achieved or no more gain can be obtained with a new relay. Once placed as a relay, the robotic node performs adaptive link maintenance by adjusting its position according to the movements of regular nodes. The simulation results show that RoCoMAR outperforms existing ad hoc routing protocols for MSN in terms of network throughput and end-to-end delay.

  13. Joint relay selection and link scheduling in cooperative free-space optical system

    NASA Astrophysics Data System (ADS)

    Tan, Yuchen; Liu, Yejun; Guo, Lei; Han, Pengchao

    2016-11-01

    Free-space optical (FSO) communication system is vulnerable to link disruption due to the propagation loss and atmospheric turbulence. Cooperative FSO system has been proposed to mitigate the adverse effects of link disruption by the cooperative transmission in assistance of relay. However, most of the related works focus on the outage probability analysis and put less attention on the resource utilization. In fact, there exists a waste of bandwidth resource due to time slot waiting and more FSO transceivers are occupied. We mainly focus on the relay selection and link scheduling mechanisms of cooperative FSO system to improve not only network reliability but also resource utilization. We first propose a relay selection algorithm as a solution to combat channel fading. In the relay selection algorithm, two cooperative modes including intrarelay-set and inter-relay-set cooperative modes are proposed to enhance network capacity. Then, a link scheduling algorithm is further proposed to improve the bandwidth utilization and reduce the occupancy rate of transceivers by utilizing more sufficiently the idle FSO links. Simulation results show that the proposed algorithms can provide significant performance gain for cooperative FSO system in reliability and resource utilization and are highly suitable for the growing traffic demands.

  14. Implementation of Pass Through PPTP Relay System with Authentication at Each Gateway and Its Performance Evaluations

    NASA Astrophysics Data System (ADS)

    Saito, Shoichi; Uehara, Tetsutaro; Izumi, Yutaka; Kunieda, Yoshitoshi

    The VPN (Virtual Private Network) technique becomes more and more popular to protect contents of messages and to achieve secure communication from incidents, such as tapping. However, it grow in usage that a VPN server is used on a sub-network in part of an office-wide network. But, a PPTP system included in Windows operating systems cannot establish nested VPN links. Moreover encrypted communication by VPN hides a user of the VPN connection. Consequently, any administrators of network systems can’t find out the users of the VPN connection via firewall, moreover can’t decide whether if the user is legal or not. In order to solve this problem, we developed a multi step PPTP relay system on a firewall. This system solves all the problems of our previously developed PPTP relay system(1). The new relay system improves security by encrypting through the whole end-to-end communication and abolishing of prior registration of passwords for the next step. Furthermore, transport speed is accelerated, and the restriction of the number of steps on relay is also abolished. By these features the multi step PPTP relay system expands usability.

  15. ac-resistance-measuring instrument

    SciTech Connect

    Hof, P.J.

    1981-04-22

    An auto-ranging ac resistance measuring instrument for remote measurement of the resistance of an electrical device or circuit connected to the instrument includes a signal generator which generates an ac excitation signal for application to a load, including the device and the transmission line, a monitoring circuit which provides a digitally encoded signal representing the voltage across the load, and a microprocessor which operates under program control to provide an auto-ranging function by which range resistance is connected in circuit with the load to limit the load voltage to an acceptable range for the instrument, and an auto-compensating function by which compensating capacitance is connected in shunt with the range resistance to compensate for the effects of line capacitance.

  16. Simultaneous distribution of AC and DC power

    DOEpatents

    Polese, Luigi Gentile

    2015-09-15

    A system and method for the transport and distribution of both AC (alternating current) power and DC (direct current) power over wiring infrastructure normally used for distributing AC power only, for example, residential and/or commercial buildings' electrical wires is disclosed and taught. The system and method permits the combining of AC and DC power sources and the simultaneous distribution of the resulting power over the same wiring. At the utilization site a complementary device permits the separation of the DC power from the AC power and their reconstruction, for use in conventional AC-only and DC-only devices.

  17. EVENT SEGMENTATION

    PubMed Central

    Zacks, Jeffrey M.; Swallow, Khena M.

    2012-01-01

    One way to understand something is to break it up into parts. New research indicates that segmenting ongoing activity into meaningful events is a core component of ongoing perception, with consequences for memory and learning. Behavioral and neuroimaging data suggest that event segmentation is automatic and that people spontaneously segment activity into hierarchically organized parts and sub-parts. This segmentation depends on the bottom-up processing of sensory features such as movement, and on the top-down processing of conceptual features such as actors’ goals. How people segment activity affects what they remember later; as a result, those who identify appropriate event boundaries during perception tend to remember more and learn more proficiently. PMID:22468032

  18. Mechanical Evolution of Relay Zones in Normal Faulted Terranes: Insights From Three Dimensional Elastoplastic Finite Element Models

    NASA Astrophysics Data System (ADS)

    Goteti, R.; Mitra, G.; Sussman, A.; Lewis, C.

    2009-05-01

    We present a 3D nonlinear finite element model to gain insights into the evolution of relay zones in normal faulted terranes. The model comprises two listric frictional sliding surfaces that act as faults and are arranged en echelon in an elastoplastic medium. We have investigated various Synthetic and Antithetic (both convergent and divergent) relay zone configurations to study the influence of (1) fault overlap/spacing ratio (-2 to 2), (2) material strength (3) coefficient of sliding friction on the faults (0.1 - 0.6) and (4) orthogonal vs. oblique extension, on the incremental evolution of stresses and strain paths in relay zones. The results suggest that a relay zone evolves in a three dimensional strain field under a combination of rotational and distortional strains. In isotropic rocks, the maximum extensional strains in the relay zone initiate oblique to regional extension and progressively rotate toward regional extension with increasing displacement on the faults. The relay zone evolves along a non-coaxial strain path and the total strain ellipsoid shape (oblate vs. prolate) is dependent on the relative orientation of the primary faults and amount of extension on them, and structural position in the relay zone. With all other parameters being identical, magnitudes of von Mises stresses at the ground surface are highest in convergent relay zones and lowest in divergent relay zones. Thus subsidiary oblique structures are more likely to develop in convergent relay zones than in synthetic or divergent relay zones. Assuming uniform fault propagation, it is possible to gain insights into relay zone evolution during fault tip propagation by comparing models with different fault overlap/spacing ratios. Model plastic strains suggest that hard linkage can develop between adjacent faults with a gap or minimal overlap; however, the occurrence of oblique, strain transferring structures increases with increasing fault overlap. The orientations of the maximum extensional

  19. Event Coverage Detection and Event Source Determination in Underwater Wireless Sensor Networks

    PubMed Central

    Zhou, Zhangbing; Xing, Riliang; Duan, Yucong; Zhu, Yueqin; Xiang, Jianming

    2015-01-01

    With the advent of the Internet of Underwater Things, smart things are deployed in the ocean space and establish underwater wireless sensor networks for the monitoring of vast and dynamic underwater environments. When events are found to have possibly occurred, accurate event coverage should be detected, and potential event sources should be determined for the enactment of prompt and proper responses. To address this challenge, a technique that detects event coverage and determines event sources is developed in this article. Specifically, the occurrence of possible events corresponds to a set of neighboring sensor nodes whose sensory data may deviate from a normal sensing range in a collective fashion. An appropriate sensor node is selected as the relay node for gathering and routing sensory data to sink node(s). When sensory data are collected at sink node(s), the event coverage is detected and represented as a weighted graph, where the vertices in this graph correspond to sensor nodes and the weight specified upon the edges reflects the extent of sensory data deviating from a normal sensing range. Event sources are determined, which correspond to the barycenters in this graph. The results of the experiments show that our technique is more energy efficient, especially when the network topology is relatively steady. PMID:26694394

  20. Event Coverage Detection and Event Source Determination in Underwater Wireless Sensor Networks.

    PubMed

    Zhou, Zhangbing; Xing, Riliang; Duan, Yucong; Zhu, Yueqin; Xiang, Jianming

    2015-12-15

    With the advent of the Internet of Underwater Things, smart things are deployed in the ocean space and establish underwater wireless sensor networks for the monitoring of vast and dynamic underwater environments. When events are found to have possibly occurred, accurate event coverage should be detected, and potential event sources should be determined for the enactment of prompt and proper responses. To address this challenge, a technique that detects event coverage and determines event sources is developed in this article. Specifically, the occurrence of possible events corresponds to a set of neighboring sensor nodes whose sensory data may deviate from a normal sensing range in a collective fashion. An appropriate sensor node is selected as the relay node for gathering and routing sensory data to sink node(s). When sensory data are collected at sink node(s), the event coverage is detected and represented as a weighted graph, where the vertices in this graph correspond to sensor nodes and the weight specified upon the edges reflects the extent of sensory data deviating from a normal sensing range. Event sources are determined, which correspond to the barycenters in this graph. The results of the experiments show that our technique is more energy efficient, especially when the network topology is relatively steady.

  1. Attempt of automated space network operations at ETS-VI experimental data relay system

    NASA Technical Reports Server (NTRS)

    Ishihara, Kiyoomi; Sugawara, Masayuki

    1994-01-01

    National Space Development Agency of Japan (NASDA) is to perform experimental operations to acquire necessary technology for the future inter-satellite communications configured with a data relay satellite. This paper intends to overview functions of the experimental ground system which NASDA has developed for the Engineering Test Satellite VI (ETS-VI) Data Relay and Tracking Experiment, and to introduce Space Network System Operations Procedure (SNSOP) method with an example of Ka-band Single Access (KSA) acquisition sequence. To reduce operational load, SNSOP is developed with the concept of automated control and monitor of both ground terminal and data relay satellite. To perform acquisition and tracking operations fluently, the information exchange with user spacecraft controllers is automated by SNSOP functions.

  2. Study on Optimization of Electromagnetic Relay's Reaction Torque Characteristics Based on Adjusted Parameters

    NASA Astrophysics Data System (ADS)

    Zhai, Guofu; Wang, Qiya; Ren, Wanbin

    The cooperative characteristics of electromagnetic relay's attraction torque and reaction torque are the key property to ensure its reliability, and it is important to attain better cooperative characteristics by analyzing and optimizing relay's electromagnetic system and mechanical system. From the standpoint of changing reaction torque of mechanical system, in this paper, adjusted parameters (armature's maximum angular displacement αarm_max, initial return spring's force Finiti_return_spring, normally closed (NC) contacts' force FNC_contacts, contacts' gap δgap, and normally opened (NO) contacts' over travel δNO_contacts) were adopted as design variables, and objective function was provided for with the purpose of increasing breaking velocities of both NC contacts and NO contacts. Finally, genetic algorithm (GA) was used to attain optimization of the objective function. Accuracy of calculation for the relay's dynamic characteristics was verified by experiment.

  3. Optimal Beamforming and Performance Analysis of Wireless Relay Networks with Unmanned Aerial Vehicle

    NASA Astrophysics Data System (ADS)

    Ouyang, Jian; Lin, Min

    2015-03-01

    In this paper, we investigate a wireless communication system employing a multi-antenna unmanned aerial vehicle (UAV) as the relay to improve the connectivity between the base station (BS) and the receive node (RN), where the BS-UAV link undergoes the correlated Rician fading while the UAV-RN link follows the correlated Rayleigh fading with large scale path loss. By assuming that the amplify-and-forward (AF) protocol is adopted at UAV, we first propose an optimal beamforming (BF) scheme to maximize the mutual information of the UAV-assisted dual-hop relay network, by calculating the BF weight vectors and the power allocation coefficient. Then, we derive the analytical expressions for the outage probability (OP) and the ergodic capacity (EC) of the relay network to evaluate the system performance conveniently. Finally, computer simulation results are provided to demonstrate the validity and efficiency of the proposed scheme as well as the performance analysis.

  4. Improved Iterative Decoding of Network-Channel Codes for Multiple-Access Relay Channel

    PubMed Central

    Majumder, Saikat; Verma, Shrish

    2015-01-01

    Cooperative communication using relay nodes is one of the most effective means of exploiting space diversity for low cost nodes in wireless network. In cooperative communication, users, besides communicating their own information, also relay the information of other users. In this paper we investigate a scheme where cooperation is achieved using a common relay node which performs network coding to provide space diversity for two information nodes transmitting to a base station. We propose a scheme which uses Reed-Solomon error correcting code for encoding the information bit at the user nodes and convolutional code as network code, instead of XOR based network coding. Based on this encoder, we propose iterative soft decoding of joint network-channel code by treating it as a concatenated Reed-Solomon convolutional code. Simulation results show significant improvement in performance compared to existing scheme based on compound codes. PMID:27347526

  5. Joint Transmit Antenna Selection and Power Allocation for ISDF Relaying Mobile-to-Mobile Sensor Networks

    PubMed Central

    Xu, Lingwei; Zhang, Hao; Gulliver, T. Aaron

    2016-01-01

    The outage probability (OP) performance of multiple-relay incremental-selective decode-and-forward (ISDF) relaying mobile-to-mobile (M2M) sensor networks with transmit antenna selection (TAS) over N-Nakagami fading channels is investigated. Exact closed-form OP expressions for both optimal and suboptimal TAS schemes are derived. The power allocation problem is formulated to determine the optimal division of transmit power between the broadcast and relay phases. The OP performance under different conditions is evaluated via numerical simulation to verify the analysis. These results show that the optimal TAS scheme has better OP performance than the suboptimal scheme. Further, the power allocation parameter has a significant influence on the OP performance. PMID:26907282

  6. Video Relay Service for Signing Deaf - Lessons Learnt from a Pilot Study

    NASA Astrophysics Data System (ADS)

    Ponsard, Christophe; Sutera, Joelle; Henin, Michael

    The generalization of high speed Internet, efficient compression techniques and low cost hardware have resulted in low cost video communication since the year 2000. For the Deaf community, this enables native communication in sign language and a better communication with hearing people over the phone. This implies that Video Relay Service can take over the old Text Relay Service which is less natural and requires mastering written language. A number of such services have developed throughout the world. The objectives of this paper are to present the experience gained in the Walloon Region of Belgium, to share a number of lessons learnt, and to provide recommendations at the technical, user adoption and political levels. A survey of video relay services around the world is presented together with the feedback from users both before and after using the pilot service.

  7. Synchrophasors-Assisted IPII-Based Intelligent Relaying for Transmission Lines Including UPFC

    NASA Astrophysics Data System (ADS)

    Jena, Manas Kumar; Samantaray, S. R.

    2015-02-01

    This paper proposes a synchrophasors-assisted intelligent relaying scheme for transmission lines compensated by Unified Power Flow Controller (UPFC). The algorithm uses a new relaying signal termed as imaginary part of integrated impedance (IPII). The synchronized phasor measurements at both ends of the transmission line are used to extract voltage and current phasors from instantaneous voltage and current signals. The voltage and current phasors are utilized to derive IPII of each phase. Further, IPII of each phase is used as input to a data-mining model termed as decision tree (DT) which provides the final relaying decision. The proposed algorithm is validated on real-time digital simulator (RTDS) platform, and the results obtained indicate that the proposed scheme is both dependable and secure in protecting transmission system compensated by UPFC.

  8. A Disynaptic Relay from Superior Colliculus to Dorsal Stream Visual Cortex in Macaque Monkey

    PubMed Central

    Lyon, David C.; Nassi, Jonathan J.; Callaway, Edward M.

    2010-01-01

    The superior colliculus (SC) is the first station in a subcortical relay of retinal information to extrastriate visual cortex. Ascending SC projections pass through pulvinar and LGN on their way to cortex, but it is not clear how many synapses are required to complete these circuits or which cortical areas are involved. To examine this relay directly, we injected transynaptic rabies virus into several extrastriate visual areas. We observed disynaptically labeled cells in superficial, retino-recipient SC layers from injections in dorsal stream areas MT and V3, but not the earliest extrastriate area, V2, nor ventral stream area V4. This robust SC-dorsal stream pathway is most likely relayed through the inferior pulvinar and can provide magnocellular-like sensory inputs necessary for motion perception and the computation of orienting movements. Furthermore, by circumventing primary visual cortex, this pathway may also underlie the remaining visual capacities associated with blindsight. PMID:20152132

  9. High excitation transfer efficiency from energy relay dyes in dye-sensitized solar cells.

    PubMed

    Hardin, Brian E; Yum, Jun-Ho; Hoke, Eric T; Jun, Young Chul; Péchy, Peter; Torres, Tomás; Brongersma, Mark L; Nazeeruddin, Md Khaja; Grätzel, Michael; McGehee, Michael D

    2010-08-11

    The energy relay dye, 4-(Dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyran (DCM), was used with a near-infrared sensitizing dye, TT1, to increase the overall power conversion efficiency of a dye-sensitized solar cell (DSC) from 3.5% to 4.5%. The unattached DCM dyes exhibit an average excitation transfer efficiency (ETE) of 96% inside TT1-covered, mesostructured TiO(2) films. Further performance increases were limited by the solubility of DCM in an acetonitrile based electrolyte. This demonstration shows that energy relay dyes can be efficiently implemented in optimized dye-sensitized solar cells, but also highlights the need to design highly soluble energy relay dyes with high molar extinction coefficients.

  10. Improved Iterative Decoding of Network-Channel Codes for Multiple-Access Relay Channel.

    PubMed

    Majumder, Saikat; Verma, Shrish

    2015-01-01

    Cooperative communication using relay nodes is one of the most effective means of exploiting space diversity for low cost nodes in wireless network. In cooperative communication, users, besides communicating their own information, also relay the information of other users. In this paper we investigate a scheme where cooperation is achieved using a common relay node which performs network coding to provide space diversity for two information nodes transmitting to a base station. We propose a scheme which uses Reed-Solomon error correcting code for encoding the information bit at the user nodes and convolutional code as network code, instead of XOR based network coding. Based on this encoder, we propose iterative soft decoding of joint network-channel code by treating it as a concatenated Reed-Solomon convolutional code. Simulation results show significant improvement in performance compared to existing scheme based on compound codes.

  11. Strategies to control alkoxy radical-initiated relay cyclizations for the synthesis of oxygenated tetrahydrofuran motifs.

    PubMed

    Zhu, Hai; Leung, Joe C T; Sammis, Glenn M

    2015-01-16

    Radical relay cyclizations initiated by alkoxy radicals are a powerful tool for the rapid construction of substituted tetrahydrofurans. The scope of these relay cyclizations has been dramatically increased with the development of two strategies that utilize an oxygen atom in the substrate to accelerate the desired hydrogen atom transfer (HAT) over competing pathways. This has enabled a chemoselective 1,6-HAT over a competing 1,5-HAT. Furthermore, this allows for a chemoselective 1,5-HAT over competing direct cyclizations and β-fragmentations. Oxygen atom incorporation leads to a general increase in cyclization diastereoselectivity over carbon analogues. This chemoselective relay cyclization strategy was utilized in the improved synthesis of the tetrahydrofuran fragment in (−)-amphidinolide K.

  12. Robust on-line relay automatic tuning of PID control systems

    PubMed

    Tan; Lee; Jiang

    2000-01-01

    In this paper, a robust on-line relay automatic tuning method for PID control systems is developed which expand on the application domain of Astrom's renowned relay autotuning method. In the proposed configuration, a relay is applied to an inner loop of a controller-stabilised process in the usual manner. Using the induced limit cycle oscillations from the closed-loop system, the controller settings may be re-tuned non-iteratively to achieve enhanced performance without disrupting closed-loop control. Two control tuning methodologies are developed -- a direct and an indirect method based on an explicit process model. Simulation examples and a real-time experiment are provided to illustrate the practical appeal and potential advantages of the proposed method over the basic one.

  13. Transformational Events

    ERIC Educational Resources Information Center

    Denning, Peter J.; Hiles, John E.

    2006-01-01

    Transformational Events is a new pedagogic pattern that explains how innovations (and other transformations) happened. The pattern is three temporal stages: an interval of increasingly unsatisfactory ad hoc solutions to a persistent problem (the "mess"), an offer of an invention or of a new way of thinking, and a period of widespread adoption and…

  14. On Proper Selection of Multihop Relays for Future Enhancement of AeroMACS Networks

    NASA Technical Reports Server (NTRS)

    Kamali, Behnam; Kerczewski, Robert J.; Apaza, Rafael D.

    2015-01-01

    As the Aeronautical Mobile Airport Communications System (AeroMACS) has evolved from a technology concept to a deployed communications network over major US airports, it is now time to contemplate whether the existing capacity of AeroMACS is sufficient to meet the demands set forth by all fixed and mobile applications over the airport surface given the AeroMACS constraints regarding bandwidth and transmit power. The underlying idea in this article is to present IEEE 802.16j-based WiMAX as a technology that can address future capacity enhancements and therefore is most feasible for AeroMACS applications. The principal argument in favor IEEE 802.16j technology is the flexible and cost effective extension of radio coverage that is afforded by relay fortified networks, with virtually no increase in the power requirements and virtually no rise in interference levels to co-allocated applications. The IEEE 802.16j-based multihop relay systems are briefly described. The focus is on key features of this technology, frame structure, and its architecture. Next, AeroMACS is described as a WiMAX-based wireless network. The two major relay modes supported by IEEE 802.16j amendment, i.e., transparent and non-transparent are described. The benefits of employing multihop relays are listed. Some key challenges related to incorporating relays into AeroMACS networks are discussed. The selection of relay type in a broadband wireless network affects a number of network parameters such as latency, signal overhead, PHY (Scalable Physical Layer) and MAC (Media Access Layer) layer protocols, consequently it can alter key network quantities of throughput and QoS (Quality of Service).

  15. Orienteering competition injuries: injuries incurred in the Finnish Jukola and Venla relay competitions.

    PubMed Central

    Linko, P E; Blomberg, H K; Frilander, H M

    1997-01-01

    OBJECTIVES: The aim of this study was to find out the amount, type, and localisation of acute orienteering injuries in the 1995 Finnish Jukola (men's) and Venla (women's) relay competitions with 9724 participants. METHODS: Patient data were collected on a preplanned form at the first aid station. RESULTS: There were 244 acute competition injuries. The overall injury incidence was 2.5% (95% confidence interval (CI) 2.2 to 2.8), 2.3% in the men's relay and 3.2% in the women's relay, and the difference between incidences among men and women was statistically significant (odds ratio (OR) 1.4; 95% CI 1.1 to 1.9). The injury rates were also calculated per 1000 competition hours and per 1000 km and were 15.4 and 2.6 respectively. Most of the injuries could be treated at the first aid station. Female orienteers had more blisters (OR 4.4; 95% CI 2.5 to 7.9) and fewer wounds (OR 0.5; 95% CI 0.2 to 1.0) than male orienteers. Injuries occurred mostly in the lower extremities (70%), and ankle sprains accounted for 25% of all injuries. Injuries were more common during the first leg of both relays. CONCLUSIONS: This study shows the heavy workload in a first aid station of a big orienteering relay competition. It indicates a difference in injuries between the sexes and in the different stages of the relay, which should be further investigated in order to prevent orienteering competition injuries. Images Figure 1 PMID:9298554

  16. Data Relay Board with Protocol for High-Speed, Free-Space Optical Communications

    NASA Technical Reports Server (NTRS)

    Wright, Malcolm; Clare, Loren; Gould, Gary; Pedyash, Maxim

    2004-01-01

    In a free-space optical communication system, the mitigation of transient outages through the incorporation of error-control methods is of particular concern, the outages being caused by scintillation fades and obscurants. The focus of this innovative technology is the development of a data relay system for a reliable high-data-rate free-spacebased optical-transport network. The data relay boards will establish the link, maintain synchronous connection, group the data into frames, and provide for automatic retransmission (ARQ) of lost or erred frames. A certain Quality of Service (QoS) can then be ensured, compatible with the required data rate. The protocol to be used by the data relay system is based on the draft CCSDS standard data-link protocol Proximity-1, selected by orbiters to multiple lander assets in the Mars network, for example. In addition to providing data-link protocol capabilities for the free-space optical link and buffering the data, the data relay system will interface directly with user applications over Gigabit Ethernet and/or with highspeed storage resources via Fibre Channel. The hardware implementation is built on a network-processor-based architecture. This technology combines the power of a hardware switch capable of data switching and packet routing at Gbps rates, with the flexibility of a software- driven processor that can host highly adaptive and reconfigurable protocols used, for example, in wireless local-area networks (LANs). The system will be implemented in a modular multi-board fashion. The main hardware elements of the data relay system are the new data relay board developed by Rockwell Scientific, a COTS Gigabit Ethernet board for user interface, and a COTS Fibre Channel board that connects to local storage. The boards reside in a cPCI back plane, and can be housed in a VME-type enclosure.

  17. The effects of DBS patterns on basal ganglia activity and thalamic relay : a computational study.

    PubMed

    Agarwal, Rahul; Sarma, Sridevi V

    2012-08-01

    Thalamic neurons receive inputs from cortex and their responses are modulated by the basal ganglia (BG). This modulation is necessary to properly relay cortical inputs back to cortex and downstream to the brain stem when movements are planned. In Parkinson's disease (PD), the BG input to thalamus becomes pathological and relay of motor-related cortical inputs is compromised, thereby impairing movements. However, high frequency (HF) deep brain stimulation (DBS) may be used to restore relay reliability, thereby restoring movements in PD patients. Although therapeutic, HF stimulation consumes significant power forcing surgical battery replacements, and may cause adverse side effects. Here, we used a biophysical-based model of the BG-Thalamus motor loop in both healthy and PD conditions to assess whether low frequency stimulation can suppress pathological activity in PD and enable the thalamus to reliably relay movement-related cortical inputs. We administered periodic pulse train DBS waveforms to the sub-thalamic nucleus (STN) with frequencies ranging from 0-140 Hz, and computed statistics that quantified pathological bursting, oscillations, and synchronization in the BG as well as thalamic relay of cortical inputs. We found that none of the frequencies suppressed all pathological activity in BG, though the HF waveforms recovered thalamic reliability. Our rigorous study, however, led us to a novel DBS strategy involving low frequency multi-input phase-shifted DBS, which successfully suppressed pathological symptoms in all BG nuclei and enabled reliable thalamic relay. The neural restoration remained robust to changes in the model parameters characterizing early to late PD stages.

  18. 77 FR 65526 - Telecommunications Relay Services and Speech-to-Speech Services for Individuals With Hearing and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-29

    ... COMMISSION 47 CFR Part 64 Telecommunications Relay Services and Speech-to-Speech Services for Individuals With Hearing and Speech Disabilities; Structure and Practices of the Video Relay Service Program AGENCY... by hand or messenger delivery, by commercial overnight courier, or by first-class or overnight...

  19. 78 FR 49717 - Speech-to-Speech and Internet Protocol (IP) Speech-to-Speech Telecommunications Relay Services...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-15

    ... COMMISSION 47 CFR Part 64 Speech-to-Speech and Internet Protocol (IP) Speech-to-Speech Telecommunications Relay Services; Telecommunications Relay Services and Speech-to-Speech Services for Individuals With Hearing and Speech Disabilities AGENCY: Federal Communications Commission. ACTION: Proposed rule....

  20. Teach for America, Relay Graduate School, and the Charter School Networks: The Making of a Parallel Education Structure

    ERIC Educational Resources Information Center

    Mungal, Angus Shiva

    2016-01-01

    In New York City, a partnership between Teach For America (TFA), the New York City Department of Education (NYCDOE), the Relay Graduate School of Education (Relay), and three charter school networks produced a "parallel education structure" within the public school system. Driving the partnership and the parallel education structure are…

  1. Frequency-selectivity of a thalamocortical relay neuron during Parkinson's disease and deep brain stimulation: a computational study.

    PubMed

    Cagnan, Hayriye; Meijer, Hil G E; van Gils, Stephan A; Krupa, Martin; Heida, Tjitske; Rudolph, Michelle; Wadman, Wytse J; Martens, Hubert C F

    2009-10-01

    In this computational study, we investigated (i) the functional importance of correlated basal ganglia (BG) activity associated with Parkinson's disease (PD) motor symptoms by analysing the effects of globus pallidus internum (GPi) bursting frequency and synchrony on a thalamocortical (TC) relay neuron, which received GABAergic projections from this nucleus; (ii) the effects of subthalamic nucleus (STN) deep brain stimulation (DBS) on the response of the TC relay neuron to synchronized GPi oscillations; and (iii) the functional basis of the inverse relationship that has been reported between DBS frequency and stimulus amplitude, required to alleviate PD motor symptoms [A. L. Benabid et al. (1991)Lancet, 337, 403-406]. The TC relay neuron selectively responded to and relayed synchronized GPi inputs bursting at a frequency located in the range 2-25 Hz. Input selectivity of the TC relay neuron is dictated by low-threshold calcium current dynamics and passive membrane properties of the neuron. STN-DBS prevented the TC relay neuron from relaying synchronized GPi oscillations to cortex. Our model indicates that DBS alters BG output and input selectivity of the TC relay neuron, providing an explanation for the clinically observed inverse relationship between DBS frequency and stimulus amplitude.

  2. Contrary roles of kainate receptors in transmitter release at corticothalamic synapses onto thalamic relay and reticular neurons.

    PubMed

    Miyata, Mariko; Imoto, Keiji

    2009-03-01

    Corticothalamic fibres, which originate from layer VI pyramidal neurons in the cerebral cortex, provide excitatory synaptic inputs to both thalamic relay neurons and reticular neurons; reticular neurons in turn supply inhibitory inputs to thalamic relay neurons. Pyramidal cells in layer VI in the mouse somatosensory cortex highly express mRNA encoding kainate receptors, which facilitate or depress transmitter release at several synapses in the central nervous system. We report here that contrary modulation of transmitter release from corticothalamic fibres onto thalamic relay and reticular neurons is mediated by activation of kainate receptors in mouse thalamic ventrobasal complex and thalamic reticular nucleus. Exogenous kainate presynaptically depresses the synaptic transmission at corticothalamic synapses onto thalamic relay neurons, but facilitates it at corticothalamic synapses onto reticular neurons. Meanwhile, the lemniscal synaptic transmission, which sends primary somatosensory inputs to relay neurons, is not affected by kainate. In addition, GluR5-containing kainate receptors are involved in the depression of corticothalamic synaptic transmission onto relay neurons, but not onto reticular neurons. Furthermore, synaptically activated kainate receptors mimic these effects; high-frequency stimulation of corticothalamic fibres depresses synaptic transmission onto relay neurons, but facilitates it onto reticular neurons. Our results suggest that the opposite sensitivity of kainate receptors at the two corticothalamic synapses is governed by cortical activity and regulates the balance of excitatory and inhibitory inputs to thalamic relay neurons and therefore their excitability.

  3. Novel controller design for plants with relay nonlinearity to reduce amplitude of sustained oscillations: Illustration with a fractional controller.

    PubMed

    Kesarkar, Ameya Anil; Selvaganesan, N; Priyadarshan, H

    2015-07-01

    This paper proposes a novel constrained optimization problem to design a controller for plants containing relay nonlinearity to reduce the amplitude of sustained oscillations. The controller is additionally constrained to satisfy desirable loop specifications. The proposed formulation is validated by designing a fractional PI controller for a plant with relay.

  4. Satellite relay telemetry of seismic data in earthquake prediction and control

    USGS Publications Warehouse

    Jackson, Wayne H.; Eaton, Jerry P.

    1971-01-01

    The Satellite Telemetry Earthquake Monitoring Program was started in FY 1968 to evaluate the applicability of satellite relay telemetry in the collection of seismic data from a large number of dense seismograph clusters laid out along the major fault systems of western North America. Prototype clusters utilizing phone-line telemetry were then being installed by the National Center for Earthquake Research (NCER) in 3 regions along the San Andreas fault in central California; and the experience of installing and operating the clusters and in reducing and analyzing the seismic data from them was to provide the raw materials for evaluation in the satellite relay telemetry project.

  5. Distributed Quantum Packet Transmission in Non-maximally Entangled Relay System

    NASA Astrophysics Data System (ADS)

    Shi, Jinjing; Shi, Ronghua; Peng, Xiaoqi; Li, Yin; Guo, Ying

    2015-04-01

    A novel distributed quantum packet transmission scheme is proposed with teleportation in the non-maximally entangled relay channel. Quantum signals are encoded as quantum signal packets and transmitted from the source to the destination with assistance of the relay. The TDM (Time Division Multiplexing) technique is applied in order to improve the efficiency of quantum communications. The security depends on the security of signal particles and an upper bound of attackers' intercepting quantum information under their strongest collective attacks is derived. The communication efficiency can be improved to four times of the traditional schemes, and the timesaving percentage may approach to 75 %. It has a wide application in quantum networks as well.

  6. Noncoherent Physical-Layer Network Coding with FSK Modulation: Relay Receiver Design Issues

    DTIC Science & Technology

    2011-03-01

    digital network coding ( DNC ) to distinguish it from ANC. Under 0090-6778/11$25.00 c⃝ 2011 IEEE Report Documentation Page Form ApprovedOMB No. 0704-0188...223 2596 IEEE TRANSACTIONS ON COMMUNICATIONS, VOL. 59, NO. 9, SEPTEMBER 2011 many channel conditions, DNC offers enhanced performance over ANC. This...is because the decoding operation at the relay helps DNC to remove noise from the MAC phase, while the noise is amplied by the relay when ANC is used

  7. Investigations of the contact bounce behaviors and relative dynamic welding phenomena for electromechanical relay.

    PubMed

    Ren, Wanbin; He, Yuan; Jin, Jianbing; Man, Sida

    2016-06-01

    Dynamic welding, being the principal mechanism of sticking failure, correlates closely with the contact bounce of electromechanical relay. The typical waveforms of dynamic contact force and contact voltage at making and breaking process are obtained with the use of a new designed test rig. The variations in bounce time, bounce numbers, last bounce duration, and relevant welding force are investigated in the electrical endurance test. It is determined that the welding strength and the welding probability are increased with the reduced stationary force. The degradation physical mechanism is present to better understand the relationship between dynamic welding and operation characteristics of electromechanical relay.

  8. Joint TAS and power allocation for DF relaying M2M cooperative system

    NASA Astrophysics Data System (ADS)

    Xu, Lingwei; Zhang, Hao; Gulliver, T. Aaron

    2016-09-01

    The outage probability (OP) performance of transmit antenna selection (TAS) in a decode-and-forward relaying mobile-to-mobile system with relay selection over N-Nakagami fading channels is investigated. Exact closed-form expressions for the OP of two TAS schemes are derived, and the optimal power allocation optimisation problem is formulated. The OP performance is evaluated via Monte Carlo simulation to verify the analysis. The results obtained show that the optimal TAS scheme has better performance than the suboptimal TAS scheme, but the performance gap between these techniques decreases as the number of source antennas increases.

  9. Using Software Zelio Soft in Educational Process to Simulation Control Programs for Intelligent Relays

    NASA Astrophysics Data System (ADS)

    Michalik, Peter; Mital, Dusan; Zajac, Jozef; Brezikova, Katarina; Duplak, Jan; Hatala, Michal; Radchenko, Svetlana

    2016-10-01

    Article deals with point to using intelligent relay and PLC systems in practice, to their architecture and principles of programming and simulations for education process on all types of school from secondary to universities. Aim of the article is proposal of simple examples of applications, where is demonstrated methodology of programming on real simple practice examples and shown using of chosen instructions. In practical part is described process of creating schemas and describing of function blocks, where are described methodologies of creating program and simulations of output reactions on changeable inputs for intelligent relays.

  10. Achievable degrees of freedom of MIMO two-way relay interference channel with delayed CSIT

    NASA Astrophysics Data System (ADS)

    Li, Qingyun; Wu, Gang; Li, Shaoqian

    2016-10-01

    In this paper, assuming each node has delayed channel state information at the transmitter (CSIT), we investigate the achievable degrees of freedom (DOF) of MIMO two-way relay interference channel in frequency division duplex (FDD) systems, where there are K user pairs (i.e., 2K users) and each user in a user pair exchanges messages with the other user in the same user pair simultaneously via an intermediate relay. We propose a two-stage transmission scheme and derive the closed-form expressions for its achievable DOF.

  11. Mars Reconnaissance Orbiter Navigation Strategy for Mars Science Laboratory Entry, Descent and Landing Telecommunication Relay Support

    NASA Technical Reports Server (NTRS)

    Williams, Jessica L.; Menon, Premkumar R.; Demcak, Stuart W.

    2012-01-01

    The Mars Reconnaissance Orbiter (MRO) is an orbiting asset that performs remote sensing observations in order to characterize the surface, subsurface and atmosphere of Mars. To support upcoming NASA Mars Exploration Program Office objectives, MRO will be used as a relay communication link for the Mars Science Laboratory (MSL) mission during the MSL Entry, Descent and Landing sequence. To do so, MRO Navigation must synchronize the MRO Primary Science Orbit (PSO) with a set of target conditions requested by the MSL Navigation Team; this may be accomplished via propulsive maneuvers. This paper describes the MRO Navigation strategy for and operational performance of MSL EDL relay telecommunication support.

  12. Relay Protection and Automation Systems Based on Programmable Logic Integrated Circuits

    SciTech Connect

    Lashin, A. V. Kozyrev, A. V.

    2015-09-15

    One of the most promising forms of developing the apparatus part of relay protection and automation devices is considered. The advantages of choosing programmable logic integrated circuits to obtain adaptive technological algorithms in power system protection and control systems are pointed out. The technical difficulties in the problems which today stand in the way of using relay protection and automation systems are indicated and a new technology for solving these problems is presented. Particular attention is devoted to the possibility of reconfiguring the logic of these devices, using programmable logic integrated circuits.

  13. Relay Forward-Link File Management Services (MaROS Phase 2)

    NASA Technical Reports Server (NTRS)

    Allard, Daniel A.; Wallick, Michael N.; Hy, Franklin H.; Gladden, Roy E.

    2013-01-01

    This software provides the service-level functionality to manage the delivery of files from a lander mission repository to an orbiter mission repository for eventual spacelink relay by the orbiter asset on a specific communications pass. It provides further functions to deliver and track a set of mission-defined messages detailing lander authorization instructions and orbiter data delivery state. All of the information concerning these transactions is persisted in a database providing a high level of accountability of the forward-link relay process.

  14. Potential future applications for the Tracking and Data Relay Satellite II (TDRS II) system

    NASA Astrophysics Data System (ADS)

    Gibbons, Richard C.

    1992-08-01

    The effect of the consideration of potential Future Service Growth (FSG) payload applications imposed on the TDRS II system is examined. The FSG applications considered include an optical 650 Mbps Space-to-Space Link coupled to an optical or RF downlink, an RF or optical crosslink to extend the baseline TDRS II system coverage, relay for lunar communications (RF or optical), and relay for Martian communications (RF or optical). The traffic requirements and link distances require very different designs for the different applications, providing little room for synergy across the various applications.

  15. Evaluating resilience of DNP3-controlled SCADA systems against event buffer flooding

    SciTech Connect

    Yan, Guanhua; Nicol, David M; Jin, Dong

    2010-12-16

    The DNP3 protocol is widely used in SCADA systems (particularly electrical power) as a means of communicating observed sensor state information back to a control center. Typical architectures using DNP3 have a two level hierarchy, where a specialized data aggregator device receives observed state from devices within a local region, and the control center collects the aggregated state from the data aggregator. The DNP3 communication between control center and data aggregator is asynchronous with the DNP3 communication between data aggregator and relays; this leads to the possibility of completely filling a data aggregator's buffer of pending events, when a relay is compromised or spoofed and sends overly many (false) events to the data aggregator. This paper investigates how a real-world SCADA device responds to event buffer flooding. A Discrete-Time Markov Chain (DTMC) model is developed for understanding this. The DTMC model is validated by a Moebius simulation model and data collected on real SCADA testbed.

  16. Rare Events

    DTIC Science & Technology

    2009-10-01

    terrorists are likely to acquire and use WMDs over the next ten years. • Provide means to target areas, entities and persons facilitating adver - sary WMD...complicated and unpredictable to begin with, but also that human adver - saries (unlike physical disasters) will react and adapt to our planning to try to make...virulent vaccine strain (Keim et al., 2001). The latter might not be regarded as a bioterrorism event, even though it caused seven deaths and incited

  17. Outage probability of a relay strategy allowing intra-link errors utilizing Slepian-Wolf theorem

    NASA Astrophysics Data System (ADS)

    Cheng, Meng; Anwar, Khoirul; Matsumoto, Tad

    2013-12-01

    In conventional decode-and-forward (DF) one-way relay systems, a data block received at the relay node is discarded, if the information part is found to have errors after decoding. Such errors are referred to as intra-link errors in this article. However, in a setup where the relay forwards data blocks despite possible intra-link errors, the two data blocks, one from the source node and the other from the relay node, are highly correlated because they were transmitted from the same source. In this article, we focus on the outage probability analysis of such a relay transmission system, where source-destination and relay-destination links, Link 1 and Link 2, respectively, are assumed to suffer from the correlated fading variation due to block Rayleigh fading. The intra-link is assumed to be represented by a simple bit-flipping model, where some of the information bits recovered at the relay node are the flipped version of their corresponding original information bits at the source. The correlated bit streams are encoded separately by the source and relay nodes, and transmitted block-by-block to a common destination using different time slots, where the information sequence transmitted over Link 2 may be a noise-corrupted interleaved version of the original sequence. The joint decoding takes place at the destination by exploiting the correlation knowledge of the intra-link (source-relay link). It is shown that the outage probability of the proposed transmission technique can be expressed by a set of double integrals over the admissible rate range, given by the Slepian-Wolf theorem, with respect to the probability density function ( pdf) of the instantaneous signal-to-noise power ratios (SNR) of Link 1 and Link 2. It is found that, with the Slepian-Wolf relay technique, so far as the correlation ρ of the complex fading variation is | ρ|<1, the 2nd order diversity can be achieved only if the two bit streams are fully correlated. This indicates that the diversity

  18. Effect of the magnetic material on AC losses in HTS conductors in AC magnetic field carrying AC transport current

    NASA Astrophysics Data System (ADS)

    Wan, Xing-Xing; Huang, Chen-Guang; Yong, Hua-Dong; Zhou, You-He

    2015-11-01

    This paper presents an investigation on the AC losses in several typical superconducting composite conductors using the H-formulation model. A single superconducting strip with ferromagnetic substrate or cores and a stack of coated conductors with ferromagnetic substrates are studied. We consider all the coated conductors carrying AC transport currents and simultaneously exposed to perpendicular AC magnetic fields. The influences of the amplitude, frequency, phase difference and ferromagnetic materials on the AC losses are investigated. The results show that the magnetization losses of single strip and stacked strips have similar characteristics. The ferromagnetic substrate can increase the magnetization loss at low magnetic field, and decrease the loss at high magnetic field. The ferromagnetic substrate can obviously increase the transport loss in stacked strips. The trends of total AC losses of single strip and stacked strips are similar when they are carrying current or exposed to a perpendicular magnetic field. The effect of the frequency on the total AC losses of single strip is related to the amplitude of magnetic field. The AC losses decrease with increasing frequency in low magnetic field region while increase in high magnetic field region. As the phase difference changes, there is a periodic variation for the AC losses. Moreover, when the strip is under only the transport current and magnetic field, the ferromagnetic cores will increase the AC losses for large transport current or field.

  19. 47 CFR 78.40 - Transition of the 1990-2025 MHz band from the Cable Television Relay Service to emerging...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Cable Television Relay Service to emerging technologies. 78.40 Section 78.40 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES CABLE TELEVISION RELAY SERVICE Applications and Licenses § 78.40 Transition of the 1990-2025 MHz band from the Cable Television Relay Service to...

  20. 49 CFR 234.247 - Purpose of inspections and tests; removal from service of relay or device failing to meet test...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... service of relay or device failing to meet test requirements. 234.247 Section 234.247 Transportation Other... tests; removal from service of relay or device failing to meet test requirements. (a) The inspections... electronic device, relay, or other electromagnetic device that fails to meet the requirements of...

  1. 49 CFR 234.247 - Purpose of inspections and tests; removal from service of relay or device failing to meet test...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... service of relay or device failing to meet test requirements. 234.247 Section 234.247 Transportation Other... Inspections and Tests § 234.247 Purpose of inspections and tests; removal from service of relay or device... operations over the grade crossing resume. (c) Any electronic device, relay, or other electromagnetic...

  2. 49 CFR 234.247 - Purpose of inspections and tests; removal from service of relay or device failing to meet test...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... service of relay or device failing to meet test requirements. 234.247 Section 234.247 Transportation Other... Inspections and Tests § 234.247 Purpose of inspections and tests; removal from service of relay or device... operations over the grade crossing resume. (c) Any electronic device, relay, or other electromagnetic...

  3. 47 CFR 78.40 - Transition of the 1990-2025 MHz band from the Cable Television Relay Service to emerging...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Cable Television Relay Service to emerging technologies. 78.40 Section 78.40 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES CABLE TELEVISION RELAY SERVICE Applications and Licenses § 78.40 Transition of the 1990-2025 MHz band from the Cable Television Relay Service to...

  4. 47 CFR 78.40 - Transition of the 1990-2025 MHz band from the Cable Television Relay Service to emerging...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Cable Television Relay Service to emerging technologies. 78.40 Section 78.40 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES CABLE TELEVISION RELAY SERVICE Applications and Licenses § 78.40 Transition of the 1990-2025 MHz band from the Cable Television Relay Service to...

  5. 49 CFR 234.247 - Purpose of inspections and tests; removal from service of relay or device failing to meet test...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... service of relay or device failing to meet test requirements. 234.247 Section 234.247 Transportation Other... tests; removal from service of relay or device failing to meet test requirements. (a) The inspections... electronic device, relay, or other electromagnetic device that fails to meet the requirements of...

  6. 49 CFR 234.247 - Purpose of inspections and tests; removal from service of relay or device failing to meet test...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... service of relay or device failing to meet test requirements. 234.247 Section 234.247 Transportation Other... tests; removal from service of relay or device failing to meet test requirements. (a) The inspections... electronic device, relay, or other electromagnetic device that fails to meet the requirements of...

  7. 47 CFR 78.40 - Transition of the 1990-2025 MHz band from the Cable Television Relay Service to emerging...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Cable Television Relay Service to emerging technologies. 78.40 Section 78.40 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES CABLE TELEVISION RELAY SERVICE Applications and Licenses § 78.40 Transition of the 1990-2025 MHz band from the Cable Television Relay Service to...

  8. ISTTOK upgrade towards AC and remote operation

    NASA Astrophysics Data System (ADS)

    Fernandes, H.; Silva, C.; Carvalho, B.; Sousa, J.; Valcárcel, D.; Neto, A.; Fortunato, J.; Carvalho, I.; Varandas, C. A. F.

    2006-12-01

    ISTTOK has performed one of the earliest experiments of AC tokamak operation showing that long discharges could be produced merely with inductive current drive. However, due to the design of the machine, the data acquisition system and the power supplies, a limit of 250 ms (six times the nominal forward shot duration) is currently imposed. In this paper the relevant constrains to attain current operation up to the limit of the stable toroidal magnetic field (3s) are discussed and the work being carried out to achieve this goal is presented. The conditions that shall be accomplished are: (i) removing the power deposited on the limiters; (ii) density control through gas puffing and monitoring the recycling from the walls; (iii) assessment of the free magnetic flux available on the iron core (Wmax=0.2 Vs); (iv) reformulation of the data acquisition system towards an event driven philosophy maintaining the actual distributed architecture but allowing a real-time control; (v) active control of the equilibrium magnetic fields implementing a digital plasma position estimator and actuator through new power supplies for the poloidal magnetic fields. As a new high level software was needed to implement all this features, the ISTTOK data acquisition system and control has been totally redesigned in JAVA/SQL database technology and time stamps events were adopted to catalogue the data. This software has been design keeping in mind the needs for remote participation and operation of the machine. Therefore, a cooperative environment has been implemented where several persons can be connected together to the platform, programming their own devices and exchanging knowledge or opinions through an embedded chat.

  9. ac electroosmosis in rectangular microchannels.

    PubMed

    Campisi, Michele; Accoto, Dino; Dario, Paolo

    2005-11-22

    Motivated by the growing interest in ac electroosmosis as a reliable no moving parts strategy to control fluid motion in microfluidic devices for biomedical applications, such as lab-on-a-chip, we study transient and steady-state electrokinetic phenomena (electroosmosis and streaming currents) in infinitely extended rectangular charged microchannels. With the aid of Fourier series and Laplace transforms we provide a general formal solution of the problem, which is used to study the time-dependent response to sudden ac applied voltage differences in case of finite electric double layer. The Debye-Huckel approximation has been adopted to allow for an algebraic solution of the Poisson-Boltzmann problem in Fourier space. We obtain the expressions of flow velocity profiles, flow rates, streaming currents, as well as expressions of the complex hydraulic and electrokinetic conductances. We analyze in detail the dependence of the electrokinetic conductance on the extension of linear dimensions relative to the Debye length, with an eye on finite electric double layer effects.

  10. ACS PSF Variations with Temperatures

    NASA Astrophysics Data System (ADS)

    Sahu, Kailash C.; Lallo, Matt; Makidon, Russ

    2007-09-01

    We have used the HST ACS/WFC observations of a Galactic bulge field taken over a continuous interval of 7 days (Prop 9750) to investigate the possible dependence of the ACS focus with the external temperatures. This dataset allows us to investigate possible focus variations over timescales of a few hours to a few days. The engineering data related to the external temperatures for this duration show that the maximum temperature change occurred over the first 1.5 days. Among all the different temperatures recorded, the truss diametric differential and the truss axial temperatures are the only two temperatures which have the same timescale of variation as the PSFwidth variations. The PSF-widths also strongly correlate with these two temperatures during this time interval. We empirically fit the PSF-width variations with these 2 temperature sensor values. This suggests that the focus has a similar dependence, and we recommend that this finding be followed up with the determination of actual focus values to check if the focus values indeed have the same correlation. If so, the temperature data can be useful in estimating the focus values, which can then be used to predict the PSFs to a first order.

  11. ac electroosmosis in rectangular microchannels

    NASA Astrophysics Data System (ADS)

    Campisi, Michele; Accoto, Dino; Dario, Paolo

    2005-11-01

    Motivated by the growing interest in ac electroosmosis as a reliable no moving parts strategy to control fluid motion in microfluidic devices for biomedical applications, such as lab-on-a-chip, we study transient and steady-state electrokinetic phenomena (electroosmosis and streaming currents) in infinitely extended rectangular charged microchannels. With the aid of Fourier series and Laplace transforms we provide a general formal solution of the problem, which is used to study the time-dependent response to sudden ac applied voltage differences in case of finite electric double layer. The Debye-Hückel approximation has been adopted to allow for an algebraic solution of the Poisson-Boltzmann problem in Fourier space. We obtain the expressions of flow velocity profiles, flow rates, streaming currents, as well as expressions of the complex hydraulic and electrokinetic conductances. We analyze in detail the dependence of the electrokinetic conductance on the extension of linear dimensions relative to the Debye length, with an eye on finite electric double layer effects.

  12. Transcranial Alternating Current Stimulation (tACS) Enhances Mental Rotation Performance during and after Stimulation

    PubMed Central

    Kasten, Florian H.; Herrmann, Christoph S.

    2017-01-01

    Transcranial alternating current stimulation (tACS) has been repeatedly demonstrated to modulate endogenous brain oscillations in a frequency specific manner. Thus, it is a promising tool to uncover causal relationships between brain oscillations and behavior or perception. While tACS has been shown to elicit a physiological aftereffect for up to 70 min, it remains unclear whether the effect can still be elicited if subjects perform a complex task interacting with the stimulated frequency band. In addition, it has not yet been investigated whether the aftereffect is behaviorally relevant. In the current experiment, participants performed a Shepard-like mental rotation task for 80 min. After 10 min of baseline measurement, participants received either 20 min of tACS at their individual alpha frequency (IAF) or sham stimulation (30 s tACS in the beginning of the stimulation period). Afterwards another 50 min of post-stimulation EEG were recorded. Task performance and EEG were acquired during the whole experiment. While there were no effects of tACS on reaction times or event-related-potentials (ERPs), results revealed an increase in mental rotation performance in the stimulation group as compared to sham both during and after stimulation. This was accompanied by increased ongoing alpha power and coherence as well as event-related-desynchronization (ERD) in the alpha band in the stimulation group. The current study demonstrates a behavioral and physiological aftereffect of tACS in parallel. This indicates that it is possible to elicit aftereffects of tACS during tasks interacting with the alpha band. Therefore, the tACS aftereffect is suitable to achieve an experimental manipulation. PMID:28197084

  13. The New Space Network: the Tracking and Data Relay Satellite System

    NASA Technical Reports Server (NTRS)

    Froehlich, W.

    1986-01-01

    When the Tracking and Data Relay Satellite System (TDRSS)is completed, the system, together with its various NASA support elements will be known simply as the Space Networks. It will substantially increase information exchanges between low-orbiting spacecraft and the ground. The structural design, functions, earth-based links, and present and future use are discussed.

  14. Dielectrophoretic Relay Assisted Molecular Communication for In-Sequence Molecule Delivery.

    PubMed

    Manocha, Puneet; Chandwani, Gitanjali; Das, Soumen

    2016-10-01

    With current research focus to interconnect the molecular communication environment with external environment, it is imperative to design external devices working on molecular communication schemes to be interfaced with in-vivo molecular network. Recently, efforts have been made to integrate molecular communication with Lab-on-chip (LOC); one of the techniques used in LOC for manipulation and transportation of molecules is Dielctrophoresis (DEP). We propose the use of DEP in molecular communication to maintain in-sequence delivery of molecules. DEP planar electrodes are modeled as relays used in telecommunications. We describe the theoretical system model and analyze the effect of introducing DEP relays in diffusive channel in terms of probability of in-sequence delivery of molecules. Information rate of DEP-based channel is analytically obtained for in-sequence delivery. The numerical results obtained show that the information rate for in-sequence delivery of molecules through diffusive channel increases by 26% if DEP relays are used in the channel. Though the system is sensitive to noise variance, incorporation of DEP relay results in a substantial improvement in the capacity of the channel.

  15. Performance Analysis of Beamforming in Fixed-gain AF Relay Networks with Asymmetric Correlated Fading Channels

    NASA Astrophysics Data System (ADS)

    Li, Min

    2014-07-01

    In this paper, the performance of beamforming (BF) for a dual-hop amplify-and-forward (AF) relay network, where the source and destination are each equipped with multiple antennas, is investigated. It is assumed that the source-relay and relay-destination channels experience mixed fading distributions, namely, correlated Nakagami-m/Rician and correlated Rician/Nakagami-m, respectively. By considering fixed-gain relaying, analytical expressions for outage probability (OP) and average symbol error rate (ASER) are derived in closed-form. Numerical results are presented to demonstrate the efficacy of our performance analysis, also illustrate the impact of channel correlation, fading severity, Rician factor and antenna configuration on the performance of the system. It is shown that the correlated Nakagami-m/Rician fading channel can achieve better performance than the correlated Rician/Nakagami-m fading channel with the increase of fading severity parameter, and the correlated Rician/Nakagami-m fading channel may outperform the correlated Nakagami-m/Rician fading channel by enlarging the Rician factor.

  16. A unified synthetic strategy to the Cryptocarya family of natural products exploiting Anion Relay Chemistry (ARC).

    PubMed

    Melillo, Bruno; Smith, Amos B

    2013-05-03

    A unified synthetic strategy to the Cryptocarya family of natural products has been achieved employing four-component fragment unions in a "single flask" exploiting Anion Relay Chemistry (ARC). Functionalization of the ARC adducts permits rapid construction of five polyhydroxylated di- and tetrahydropyrone natural products of the Cryptocarya class (1-5), in a total of 7-9 steps from commercially available materials.

  17. Potential future applications for the tracking and data relay satellite II (TDRS II) system

    NASA Astrophysics Data System (ADS)

    Gibbons, Richard C.

    1995-04-01

    During the conceptual design phases of the tracking and data relay satellite (TDRS) II system provision was made for a future service growth (FSG) payload with an undefined mission. The intent of the FSG was to provide a resource for TDRS II applications which would be available to meet a change in requirements for the operational TDRS II system. This paper summarizes the effect of the consideration of potential FSG applications imposed on the tracking and data relay satellite (TDRS) II system. The following applications were considered as FSG candidates: An optical 650 Mbps space-to-space link (SSL) coupled to an optical or RF downlink, an RF or optical crosslink to extend the baseline TDRS II system coverage, -zone of exclusion (ZOE) closure, relay for lunar communications either RF or optically, and relay for Martian communications either RF or optically. This paper summarizes work done in the 1990 time frame on the above stated applications. Since then, NASA has sponsored several studies (during phase B of the TDRS II development cycle) of the ZOE closure application of the FSG. The purpose of this paper is to report on the efforts previously considered for the FSG. A previous paper was presented at the 1991 Congress related to the second application above. This paper extends this effort to the four stated applications.

  18. Potential future applications for the tracking and data relay satellite II (TDRS II) system

    NASA Technical Reports Server (NTRS)

    Gibbons, Richard C.

    1995-01-01

    During the conceptual design phases of the tracking and data relay satellite (TDRS) II system provision was made for a future service growth (FSG) payload with an undefined mission. The intent of the FSG was to provide a resource for TDRS II applications which would be available to meet a change in requirements for the operational TDRS II system. This paper summarizes the effect of the consideration of potential FSG applications imposed on the tracking and data relay satellite (TDRS) II system. The following applications were considered as FSG candidates: An optical 650 Mbps space-to-space link (SSL) coupled to an optical or RF downlink, an RF or optical crosslink to extend the baseline TDRS II system coverage, -zone of exclusion (ZOE) closure, relay for lunar communications either RF or optically, and relay for Martian communications either RF or optically. This paper summarizes work done in the 1990 time frame on the above stated applications. Since then, NASA has sponsored several studies (during phase B of the TDRS II development cycle) of the ZOE closure application of the FSG. The purpose of this paper is to report on the efforts previously considered for the FSG. A previous paper was presented at the 1991 Congress related to the second application above. This paper extends this effort to the four stated applications.

  19. High-performance inkjet-printed four-terminal microelectromechanical relays and inverters.

    PubMed

    Chung, Seungjun; Ul Karim, Muhammed Ahosan; Kwon, Hyuk-Jun; Subramanian, Vivek

    2015-05-13

    We report the first demonstration of inkjet-printed 4-terminal microelectromechanical (MEM) relays and inverters with hyper-abrupt switching that exhibit excellent electrical and mechanical characteristics. This first implementation of a printed 4-terminal device is critically important, since it allows for the realization of full complementary logic functions. The floated fourth terminal (body electrode), which allows the gate switching voltage to be adjusted, is bonded to movable channel beams via a printed epoxy layer in a planar structure, which can move downward together via the electrostatic force between the gate electrodes and body such that the channel can also actuate downward and touch the drain electrode. Because the body, channel, and drain electrodes are completely electrically separated, no detectable leakage or electrical interference between the electrodes is observed. The printed MEM relay exhibited an on-state resistance of only 3.48 Ω, immeasurable off-state leakage, subthreshold swing <1 mV/dec, and a stable operation over 10(4) cycles with a switching delay of 47 μs, and the relay inverter exhibits abrupt transitions between on/off states. The operation of the printed 4-terminal MEM relay was also verified against the results of a 3-dimensional (3D) finite element simulation.

  20. Cooperative Transmission for Relay Networks Based on Second-Order Statistics of Channel State Information

    NASA Astrophysics Data System (ADS)

    Li, Jiangyuan; Petropulu, Athina P.; Poor, H. Vincent

    2011-03-01

    Cooperative beamforming in relay networks is considered, in which a source transmits to its destination with the help of a set of cooperating nodes. The source first transmits locally. The cooperating nodes that receive the source signal retransmit a weighted version of it in an amplify-and-forward (AF) fashion. Assuming knowledge of the second-order statistics of the channel state information, beamforming weights are determined so that the signal-to-noise ratio (SNR) at the destination is maximized subject to two different power constraints, i.e., a total (source and relay) power constraint, and individual relay power constraints. For the former constraint, the original problem is transformed into a problem of one variable, which can be solved via Newton's method. For the latter constraint, the original problem is transformed into a homogeneous quadratically constrained quadratic programming (QCQP) problem. In this case, it is shown that when the number of relays does not exceed three the global solution can always be constructed via semidefinite programming (SDP) relaxation and the matrix rank-one decomposition technique. For the cases in which the SDP relaxation does not generate a rank one solution, two methods are proposed to solve the problem: the first one is based on the coordinate descent method, and the second one transforms the QCQP problem into an infinity norm maximization problem in which a smooth finite norm approximation can lead to the solution using the augmented Lagrangian method.

  1. Direct transmission detection of tunable mechanical resonance in an individual carbon nanofiber relay.

    PubMed

    Eriksson, Anders; Lee, SangWook; Sourab, Abdelrahim A; Isacsson, Andreas; Kaunisto, Risto; Kinaret, Jari M; Campbell, Eleanor E B

    2008-04-01

    A direct on-chip transmission measurement of the resonance frequency of an individual singly clamped carbon nanofiber relay is reported. The experimental results are in good agreement with a small signal model and show the expected tuning of the resonance frequency with changing bias voltage.

  2. High power excimer laser image relay system analysis using Delano diagram

    NASA Astrophysics Data System (ADS)

    Zhang, Yongshen; Zhao, Jun; Zhao, Xueqing; Hu, Yun; Wang, Dahui; Xue, Quanxi; Liu, Jingru

    2013-05-01

    The characteristics of Delano diagram are especially helpful in instrumental systems type with considerably separated components. For high power excimer laser system, especially for image relay scheme, the Delano diagram method is highly advantageous for the system's thin lens layout design. A primitive experimental image relay and it's combination optical layout is investigated in our high power XeCl laser system, with intensity smoothed spatial incoherent source. Instead of the uniform intensity distribution on the target as expected, it is obvious shows in the final image on the target that a gauss like intensity profile and a large amount of astigmatism results. There are two possible reasons: the first one is that not keeping proper relay of pupil plane (or Fourier plane) in the final stage, simply care the collimated beam of virtual object in the final focusing stage. With the help of Delano diagram, it's clearly shown in the diagram that the Fourier plane and the image plane come very close, indicates that a complete image relay of the object plane and Fourier plane is needed. The second reason is due to the off-axis setup in the large aperture main amplifier, which introduce significant astigmatism aberrations in the final optical path. This question can be solved using proper tilt and de-center of reflective mirror pair setup, and two possible such combination pairs are proposed.

  3. Curtain Time 20:00 GMT: Experiments in Virtual Theater on Internet Relay Chat.

    ERIC Educational Resources Information Center

    Danet, Brenda; And Others

    1995-01-01

    Analyzes the substantive and stylistic features of the "Hamnet" script (an 80-line parody of "Hamlet") as performed on Internet Relay Chat. Explicates the logistics of virtual production. Finds evidence for the democratization and globalization of culture in Hamnet productions. Suggests that Hamnet activities appeal primarily…

  4. Rate Control for Network-Coded Multipath Relaying with Time-Varying Connectivity

    DTIC Science & Technology

    2010-12-10

    currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1. REPORT DATE ( DD -MM-YYYY) 2. REPORT TYPE 3. DATES...Retransmission Interval 2.0 sec, and SPF Calculation Delay and Hold Time to 0 sec. For flooding, each of the N relay nodes is able to receive all

  5. 78 FR 53684 - Misuse of Internet Protocol (IP) Captioned Telephone Service; Telecommunications Relay Services...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-30

    ... does not require special skills such as sign language, is generally automated and invisible to the... service (IP CTS) is a form of telecommunications relay service (TRS) that permits people who can speak, but who have difficulty hearing over the telephone, to speak directly to another party on a...

  6. Tracking and data relay satellite system configuration and tradeoff study. Volume 8: Appendixes, part 1

    NASA Technical Reports Server (NTRS)

    Hill, T. E.

    1973-01-01

    The appendices to support the data involved in the design and development of the Tracking and Data Relay satellite are presented. The subjects discussed are: (1) spacecraft structural body shapes, (2) antenna configurations, (3) solar configurations, (4) telemetry equipment, and (5) reliability design practices.

  7. Double- and relay-cropping oilseed and biomass crops for sustainable energy production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Double- and relay-cropping offers a means to produce a biofuel and food or forage crop in a single season on the same land without sacrificing food security, while potentially boosting profits. Field studies were conducted between 2009 and 2012 in Morris, Minnesota (MN), and Prosper and Carrington, ...

  8. 75 FR 44964 - Structure and Practices of the Video Relay Service Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-30

    ... [Federal Register Volume 75, Number 146 (Friday, July 30, 2010)] [Notices] [Page 44964] [FR Doc No: C1-2010-17575] FEDERAL COMMUNICATIONS COMMISSION [CG Docket No. 10-51; FCC 10-111] Structure and Practices of the Video Relay Service Program Correction In notice document 10-17575 beginning on page...

  9. Double- and relay-cropping of energy crops in the northern Great Plains, USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In a growing developing world, innovative cropping systems are necessary to obtain continuous and sustainable supplies of food, feed, fuel, and bio-based products. Double- and relay- cropping systems are an option to produce biofuels, food, and biomass feedstock in a single season on the same land w...

  10. High accuracy alignment of the RC system coupled with the relay lens

    NASA Astrophysics Data System (ADS)

    Mu, Shengbo; Li, Yang; Du, Guojun; Xin, Wei; Zhang, Qingchun

    2016-10-01

    The area array CMOS devices are usually used on the staring imaging space remote sensors on which the wide field angle. Only an RC system cannot match the requirement. So at present, the RC system coupled with a group of relay lens which is always used in the long focal length and wide field angle system can extend the field angle because the aberration of off axis of the RC system can be corrected by the relay lens. In order to reach the high precision alignment of the system, the computer aided alignment technology and the high precision spatial location reconfiguration technology will be introduced. Comparing with the group of relay lens and the secondary mirror both adjusted, this method fixed the group of relay lens. It made the secondary mirror be the only variable. The number of the variable of the alignment was reduced. The efficiency of the alignment was also improved and the period was shortened. The result was that the MTF of all the nine field angles was better than 0.315, which the design result was 0.345. The factor of the alignment was 91 percent.

  11. Corynebacterium diphtheriae methionine sulfoxide reductase a exploits a unique mycothiol redox relay mechanism.

    PubMed

    Tossounian, Maria-Armineh; Pedre, Brandán; Wahni, Khadija; Erdogan, Huriye; Vertommen, Didier; Van Molle, Inge; Messens, Joris

    2015-05-01

    Methionine sulfoxide reductases are conserved enzymes that reduce oxidized methionines in proteins and play a pivotal role in cellular redox signaling. We have unraveled the redox relay mechanisms of methionine sulfoxide reductase A of the pathogen Corynebacterium diphtheriae (Cd-MsrA) and shown that this enzyme is coupled to two independent redox relay pathways. Steady-state kinetics combined with mass spectrometry of Cd-MsrA mutants give a view of the essential cysteine residues for catalysis. Cd-MsrA combines a nucleophilic cysteine sulfenylation reaction with an intramolecular disulfide bond cascade linked to the thioredoxin pathway. Within this cascade, the oxidative equivalents are transferred to the surface of the protein while releasing the reduced substrate. Alternatively, MsrA catalyzes methionine sulfoxide reduction linked to the mycothiol/mycoredoxin-1 pathway. After the nucleophilic cysteine sulfenylation reaction, MsrA forms a mixed disulfide with mycothiol, which is transferred via a thiol disulfide relay mechanism to a second cysteine for reduction by mycoredoxin-1. With x-ray crystallography, we visualize two essential intermediates of the thioredoxin relay mechanism and a cacodylate molecule mimicking the substrate interactions in the active site. The interplay of both redox pathways in redox signaling regulation forms the basis for further research into the oxidative stress response of this pathogen.

  12. Excision Patterns of Activator (Ac) and Dissociation (Ds) Elements in Zea Mays L.: Implications for the Regulation of Transposition

    PubMed Central

    Heinlein, M.

    1996-01-01

    The pattern of aleurone variegation of maize kernels carrying Ac and bz-m2(DI) as reporter allele for Ac activity depends on the dosage of both Ac and Ds. Alterations of Ac dosage can abolish Ds excision at certain times and allow it to occur at other times. wx-m7 and wx-m9 are different Ac insertions in the Waxy gene which have different dosage effects on Ds excision. Kernels, heterozygous for the two Ac alleles and being either wx-m7/wx-m7/wx-m9 or wx-m9/wx-m9/wx-m7 exhibit characteristic patterns of predominantly late excisions; this is in strong contrast to the pattern of early excisions present on wx-m7/wx-m7/wx-m7 homozygotes. This observation supports the hypothesis that the Ac alleles express different amounts of transposase (TPase) during development and that above a certain level of TPase transposition is inhibited. Furthermore, experimental results suggest that the frequency of Ac-induced events is influenced by the dosage and composition of the transactivated Ds or Ac allele. Thus, transposition frequency seems not to be exclusively determined in trans by the amount of active TPase, but also by specific cis-acting properties of the TPase substrate. PMID:8978069

  13. RHIC spin flipper AC dipole controller

    SciTech Connect

    Oddo, P.; Bai, M.; Dawson, C.; Gassner, D.; Harvey, M.; Hayes, T.; Mernick, K.; Minty, M.; Roser, T.; Severino, F.; Smith, K.

    2011-03-28

    The RHIC Spin Flipper's five high-Q AC dipoles which are driven by a swept frequency waveform require precise control of phase and amplitude during the sweep. This control is achieved using FPGA based feedback controllers. Multiple feedback loops are used to and dynamically tune the magnets. The current implementation and results will be presented. Work on a new spin flipper for RHIC (Relativistic Heavy Ion Collider) incorporating multiple dynamically tuned high-Q AC-dipoles has been developed for RHIC spin-physics experiments. A spin flipper is needed to cancel systematic errors by reversing the spin direction of the two colliding beams multiple times during a store. The spin flipper system consists of four DC-dipole magnets (spin rotators) and five AC-dipole magnets. Multiple AC-dipoles are needed to localize the driven coherent betatron oscillation inside the spin flipper. Operationally the AC-dipoles form two swept frequency bumps that minimize the effect of the AC-dipole dipoles outside of the spin flipper. Both AC bumps operate at the same frequency, but are phase shifted from each other. The AC-dipoles therefore require precise control over amplitude and phase making the implementation of the AC-dipole controller the central challenge.

  14. ACS/HRC Internal Assessment of Data Quality

    NASA Astrophysics Data System (ADS)

    Sirianni, Marco

    2006-07-01

    This program will assess the functionality of HRC after the ACS Suspend event that occurred on day 266 2006.A series of Bias, 0.1 sec pseudo dark, Dark and internal flat will be executed through amps A and B to assessdata quality.10-09-2006 : visits 01-03 should be withdrawn. 10-10-2006: visits 04-07 contains bias and dark frames to allow the creation of reference files using the standardamount of images. Two pairs of internal flats have been added for sanity checks.

  15. Differential distribution of the KCl cotransporter KCC2 in thalamic relay and reticular nuclei

    PubMed Central

    Barthó, P.; Payne, J. A.; Freund, T. F.; Acsády, L.

    2009-01-01

    In the thalamus of the rat the reversal potential of GABA-induced anion currents is more negative in relay cells than in neurones of the reticular nucleus (nRt) due to different chloride extrusion mechanisms operating in these cells. The distribution of KCl cotransporter type 2 (KCC2), the major neuronal chloride transporter that may underlie this effect, is unknown in the thalamus. In this study the precise regional and ultrastructural localization of KCC2 was examined in the thalamus using immunocytochemical methods. The neuropil of all relay nuclei was found to display intense KCC2 immunostaining to varying degrees. In sharp contrast, the majority of the nRt was negative for KCC2. In the anterior and dorsal part of the nRt, however, KCC2 immunostaining was similar to relay nuclei and parvalbumin and calretinin were found to colocalize with KCC2. At the ultrastructural level, KCC2 immunoreactivity was mainly located in the extrasynaptic membranes of thick and thin dendrites and the somata of relay cells but was also found in close association with asymmetrical synapses formed by cortical afferents. Quantitative evaluation of KCC2 distribution at the electron microscopic level demonstrated that the density of KCC2 did not correlate with dendritic diameter or synaptic coverage but is 1.7 times higher on perisynaptic membrane surfaces than on extrasynaptic membranes. Our data demonstrate that the regional distribution of KCC2 is compatible with the difference in GABA-A reversal potential between relay and reticular nuclei. At the ultrastructural level, abundant extrasynaptic KCC2 expression will probably play a role in the regulation of extrasynaptic GABA-A receptor-mediated inhibition. PMID:15305865

  16. Achievable rate maximization for decode-and-forward MIMO-OFDM networks with an energy harvesting relay.

    PubMed

    Du, Guanyao; Yu, Jianjun

    2016-01-01

    This paper investigates the system achievable rate for the multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) system with an energy harvesting (EH) relay. Firstly we propose two protocols, time switching-based decode-and-forward relaying (TSDFR) and a flexible power splitting-based DF relaying (PSDFR) protocol by considering two practical receiver architectures, to enable the simultaneous information processing and energy harvesting at the relay. In PSDFR protocol, we introduce a temporal parameter to describe the time division pattern between the two phases which makes the protocol more flexible and general. In order to explore the system performance limit, we discuss the system achievable rate theoretically and formulate two optimization problems for the proposed protocols to maximize the system achievable rate. Since the problems are non-convex and difficult to solve, we first analyze them theoretically and get some explicit results, then design an augmented Lagrangian penalty function (ALPF) based algorithm for them. Numerical results are provided to validate the accuracy of our analytical results and the effectiveness of the proposed ALPF algorithm. It is shown that, PSDFR outperforms TSDFR to achieve higher achievable rate in such a MIMO-OFDM relaying system. Besides, we also investigate the impacts of the relay location, the number of antennas and the number of subcarriers on the system performance. Specifically, it is shown that, the relay position greatly affects the system performance of both protocols, and relatively worse achievable rate is achieved when the relay is placed in the middle of the source and the destination. This is different from the MIMO-OFDM DF relaying system without EH. Moreover, the optimal factor which indicates the time division pattern between the two phases in the PSDFR protocol is always above 0.8, which means that, the common division of the total transmission time into two equal phases in

  17. Geophysical events

    NASA Astrophysics Data System (ADS)

    This is a summary of SEAN Bulletin, 13(2), February 29, 1988, a publication of the Smithsonian Institution's Scientific Event Alert Network. The complete bulletin is available in the microfiche edition of Eos as a microfiche supplement or as a paper reprint. For the microfiche, order document E88-002 at $2.50 (U.S.) by writing to AGU Orders, 2000 Florida Avenue, N.W., Washington, DC 20009 or by calling toll free on 800-424-2488. For the paper reprint, order SEAN Bulletin (giving volume and issue numbers and issue date) through the same address; the price is $3.50 for one copy of each issue number for those who do not have a deposit account, $2 for those who do; additional copies of each issue number are $ 1.

  18. Applications of satellite data relay to problems of field seismology

    NASA Technical Reports Server (NTRS)

    Webster, W. J., Jr.; Miller, W. H.; Whitley, R.; Allenby, R. J.; Dennison, R. T.

    1980-01-01

    A seismic signal processor was developed and tested for use with the NOAA-GOES satellite data collection system. Performance tests on recorded, as well as real time, short period signals indicate that the event recognition technique used is nearly perfect in its rejection of cultural signals and that data can be acquired in many swarm situations with the use of solid state buffer memories. Detailed circuit diagrams are provided. The design of a complete field data collection platform is discussed and the employment of data collection platforms in seismic network is reviewed.

  19. Are you ready for Mars? - Main media events surrounding the arrival of ESA's Mars Express at Mars

    NASA Astrophysics Data System (ADS)

    2003-11-01

    relating to the arrival of Mars Express at its destination will be marked by several media events not to be missed. Pencil them into your diaries so as not to miss one of the most exciting events of the year. Tuesday 11 November Mars Express/Beagle 2 Media briefing Royal Society- 6-9 Carlton House Terrace, London 10:00 - 13:00 -Status report on the mission -Technical details on forthcoming Mars Express/Beagle 2 operations -News handling arrangements around Christmas Speakers: Prof. David Southwood, ESA Director of Science; Prof. Colin Pillinger, Beagle 2 Lander Lead Scientist; John Reddy, ESA Mars Express Principal Electrical Systems Engineer. Contact: Peter Barratt, PPARC Tel. + 44 (0) 1793 44 20 25 e-mail: Beagle2@pparc.ac.uk Wednesday 3 December ESA Media briefing ESA/ ESOC, Darmstadt, Germany 10:30 - 12:30 -Scientific outlook and expected results -Status report on the mission -Presentation of upcoming events Speakers: Rudolf Schmidt, ESA Mars Express Project Manager; Augustin Chicarro, ESA Mars Express Project Scientist. In addition, Mars Express scientists and Mission Control Managers will highlight their contribution to the Mars Express mission. In videoconference with ESA/Headquarters, Paris (F); ESA/ESTEC, Noordwijk (NL), ESA/ESRIN, Frascati (I). Contact: Jocelyne Landeau Constantin, ESA/ESOC Tel. + 49 6151 90 26 96 e-mail: Jocelyne.Landeau-Constantin@esa.int Friday 19 December Mars Express Orbiter/ Beagle 2 separation Mission Control Managers announce results of Beagle 2 separation from the mother craft. a.Event at ESA/ESOC, Darmstadt , Germany 08:30 - 14:00 Speakers: Prof. David Southwood, ESA Director of Science; Rudolf Schmidt, ESA Mars Express Project Manager Contact: Jocelyne Landeau Constantin, ESA/ESOC Tel. + 49 6151 90 26 96 e-mail: Jocelyne.Landeau-Constantin@esa.int b.Event in London -location and time t.b.c. Speaker: Prof. Colin Pillinger, Beagle 2 Lander Lead Scientist. Contact: Peter Barratt, PPARC Tel. + 44 (0) 1793 44 20 25 e-mail: Beagle2@pparc.ac

  20. Events diary

    NASA Astrophysics Data System (ADS)

    2000-01-01

    as Imperial College, the Royal Albert Hall, the Royal College of Art, the Natural History and Science Museums and the Royal Geographical Society. Under the heading `Shaping the future together' BA2000 will explore science, engineering and technology in their wider cultural context. Further information about this event on 6 - 12 September may be obtained from Sandra Koura, BA2000 Festival Manager, British Association for the Advancement of Science, 23 Savile Row, London W1X 2NB (tel: 0171 973 3075, e-mail: sandra.koura@britassoc.org.uk ). Details of the creating SPARKS events may be obtained from creating.sparks@britassoc.org.uk or from the website www.britassoc.org.uk . Other events 3 - 7 July, Porto Alegre, Brazil VII Interamerican conference on physics education: The preparation of physicists and physics teachers in contemporary society. Info: IACPE7@if.ufrgs.br or cabbat1.cnea.gov.ar/iacpe/iacpei.htm 27 August - 1 September, Barcelona, Spain GIREP conference: Physics teacher education beyond 2000. Info: www.blues.uab.es/phyteb/index.html

  1. Structure and practices of the video relay service program; telecommunications relay services and speech-to-speech services for individuals with hearing and speech disabilities. Final rule.

    PubMed

    2013-07-05

    In this document, the Commission adopts further measures to improve the structure, efficiency, and quality of the video relay service (VRS) program, reducing the inefficiencies in the program, as well as reducing the risk of waste, fraud, and abuse, and ensuring that the program makes full use of advances in commercially-available technology. These measures involve a fundamental restructuring of the program to support innovation and competition, drive down ratepayer and provider costs, eliminate incentives for waste that have burdened the Telecommunications Relay Services (TRS) Fund in the past, and further protect consumers. The Commission adopts several measures in order to: ensure that VRS users can easily select their provider of choice by promoting the development of interoperability and portability standards; enable consumers to use off-the-shelf devices and deploying a VRS application to work with these devices; create a centralized TRS User Registration Database to ensure VRS user eligibility; encourage competition and innovation in VRS call handling services; spur research and development on VRS services by entering into a Memorandum of Understanding with the National Science Foundation; and pilot a National Outreach Program to educate the general public about relay services. In this document, the Commission also adopts new VRS compensation rates that move these rates toward actual costs over the next four years which will better approximate the actual, reasonable costs of providing VRS, and will reduce the costs of operating the program. The Commission takes these steps to ensure the integrity of the TRS Fund while providing stability and certainty to providers.

  2. Geophysical events

    NASA Astrophysics Data System (ADS)

    This is a summary of SEAN Bulletin, 13 (6), June 30, 1988, a publication of the Smithsonian Institution's Scientific Event Alert Network. The complete bulletin is available in the microfiche edition of Eos as a microfiche supplement or as a paper reprint. For the microfiche, order document E88-005 at $2.50 (U.S.) by writing to AGU Orders, 2000 Florida Avenue, N.W., Washington, DC 20009 or by calling toll free on 800-424-2488. For the paper reprint, order SEAN Bulletin (giving volume and issue numbers and issue date) through the same address; the price is $3.50 for one copy of each issue number for those who do not have a deposit account, $2 for those who do; additional copies of each issue number are $ 1. Subscriptions to SEAN Bulletin are also available from AGU-Orders; the price is $18 for 12 monthly issues mailed to a U.S. address, $28 if mailed elsewhere, and must be prepaid. SEAN Bulletin is available on Kosmos. Type CHECK SEAN on Part A of Kosmos.

  3. Geophysical events

    NASA Astrophysics Data System (ADS)

    This is a summary of SEAN Bulletin, 25(10), October 31, 1988, a publication of the Smithsonian Institution's Scientific Event Alert Network. The complete bulletin is available in the microfiche edition of Eos as a microfiche supplement or as a paper reprint. For the microfiche, order document E88-010 at $2.50 (U.S.) by writing to AGU Orders, 2000 Florida Avenue, N.W., Washington, DC 20009 or by calling toll free on 800-424-2488. For the paper reprint, order SEAN Bulletin (giving volume and issue numbers and issue date) through the same address; the price is $3.50 for one copy of each issue number for those who do not have a deposit account, $2 for those who do; additional copies of each issue number are $ 1 . Subscriptions to SEAN Bulletin are also available from AGU-Orders; the price is $18 for 12 monthly issues mailed to a U.S. address, $28 if mailed elsewhere, and must be prepaid. SEAN Bulletin is available on Kosmos. Type CHECK SEAN on Part A of Kosmos

  4. Geophysical events

    NASA Astrophysics Data System (ADS)

    This is a summary of SEAN Bulletin, 13(3), March 31, 1988, a publication of the Smithsonian Institution's Scientific Event Alert Network. The complete bulletin is available in the microfiche edition of Eos as a microfiche supplement or as a paper reprint. For the microfiche, order document E88-002 at $2.50 (U.S.) by writing to AGU Orders, 2000 Florida Avenue, N.W., Washington, DC 20009 or by calling toll free on 800-424-2488. For the paper reprint, order SEAN Bulletin (giving volume and issue numbers and issue date) through the same address; the price is $3.50 for one copy of each issue number for those who do not have a deposit account, $2 for those who do; additional copies of each issue number are $1. Subscriptions to SEAN Bulletin are also available from AGU-Orders; the price is $18 for 12 monthly issues mailed to a U.S. address, $28 if mailed elsewhere, and must be prepaid.

  5. Geophysical events

    NASA Astrophysics Data System (ADS)

    This is a summary of SEAN Bulletin, 13 (7), July 31, 1988, a publication of the Smithsonian Institution's Scientific Event Alert Network. The complete bulletin is available in the microfiche edition of Eos as a microfiche supplement or as a paper reprint. For the microfiche, order document E88-007 at $2.50 (U.S.) by writing to AGU Orders, 2000 Florida Avenue, N.W., Washington, DC 20009 or by calling toll free on 800-424-2488. For the paper reprint, order SEAN Bulletin (giving volume and issue numbers and issue date) through the same address; the price is $3.50 for one copy of each issue number for those who do not have a deposit account, $2 for those who do; additional copies of each issue number are $1. Subscriptions to SEAN Bulletin are also available from AGU-Orders; the price is $18 for 12 monthly issues mailed to a U.S. address, $28 if mailed elsewhere, and must be prepaid. SEAN Bulletin is available on Kosmos. Type CHECK SEAN on Part A of Kosmos.

  6. Geophysical events

    NASA Astrophysics Data System (ADS)

    This is a summary of SEAN Bulletin, 13 (1), January 31, 1988, a publication of the Smithsonian Institution's Scientific Event Alert Network. The complete bulletin is available in the microfiche edition of Eos as a microfiche supplement or as a paper reprint. For the microfiche, order document E88-001 at $2.50 (U.S.) by writing to AGU Orders, 2000 Florida Avenue, N.W., Washington, DC 20009 or by calling toll free on 800-424-2488. For the paper reprint, order SEAN Bulletin (giving volume and issue numbers and issue date) through the same address; the price is $3.50 for one copy of each issue number for those who do not have a deposit account, $2 for those who do; additional copies of each issue number are $ 1. Subscriptions to SEAN Bulletin are also available from AGU Orders; the price is $18 for 12 monthly issues mailed to a U.S. address, $28 if mailed elsewhere, and must be prepaid.

  7. Geophysical events

    NASA Astrophysics Data System (ADS)

    This is a summary of SEAN Bulletin, 13(9), September 30, 1988, a publication of the Smithsonian Institution's Scientific Event Alert Network. The complete bulletin is available in the microfiche edition of Eos as a microfiche supplement or as a paper reprint. For the microfiche, order document E88-013 at $2.50 (U.S.) by writing to AGU Orders, 2000 Florida Avenue, N.W., Washington, DC 20009 or by calling toll free on 800-424-2488. For the paper reprint, order SEAN Bulletin (giving volume and issue numbers and issue date) through the same address; the price is $3.50 for one copy of each issue number for those who do not have a deposit account, $2 for those who do; additional copies of each issue number are $1. Subscriptions to SEAN Bulletin are also available from AGU-Orders; the price is $18 for 12 monthly issues mailed to a U.S. address, $28 if mailed elsewhere, and must be prepaid. SEAN Bulletin is available on Kosmos. Type CHECK SEAN on Part A of Kosmos.

  8. Geophysical events

    NASA Astrophysics Data System (ADS)

    This is a summary of SEAN Bulletin, 13 (5), May 31, 1988, a publication of the Smithsonian Institution's Scientific Event Alert Network. The complete bulletin is available in the microfiche edition of Eos as a microfiche supplement or as a paper reprint. For the microfiche, order document E88-004 at $2.50 (U.S.) by writing to AGU Orders, 2000 Florida Avenue, N.W., Washington, DC 20009 or by calling toll free on 800-424-2488. For the paper reprint, order SEAN Bulletin (giving volume and issue numbers and issue date) through the same address; the price is $3.50 for one copy of each issue number for those who do not have a deposit account, $2 for those who do; additional copies of each issue number are $ 1. Subscriptions to SEAN Bulletin are also available from AGU-Orders; the price is $18 for 12 monthly issues mailed to a U.S. address, $28 if mailed elsewhere, and must be prepaid. SEAN Bulletin is available on Kosmos. Type CHECK SEAN on Part A of Kosmos.

  9. Soil Chemical Property Changes in Eggplant/Garlic Relay Intercropping Systems under Continuous Cropping

    PubMed Central

    Wang, Mengyi; Wu, Cuinan; Cheng, Zhihui; Meng, Huanwen; Zhang, Mengru; Zhang, Hongjing

    2014-01-01

    Soil sickness is a critical problem for eggplant (Solanum melongena L.) under continuous cropping that affects sustainable eggplant production. Relay intercropping is a significant technique on promoting soil quality, improving eco-environment, and raising output. Field experiments were conducted from September 2010 to November 2012 in northwest China to determine the effects of relay intercropping eggplant with garlic (Allium sativum L.) on soil enzyme activities, available nutrient contents, and pH value under a plastic tunnel. Three treatments were in triplicate using randomized block design: eggplant monoculture (CK), eggplant relay intercropping with normal garlic (NG) and eggplant relay intercropping with green garlic (GG). The major results are as follows: (1) the activities of soil invertase, urease, and alkaline phosphatase were generally enhanced in NG and GG treatments; (2) relay intercropping significantly increased the soil available nutrient contents, and they were mostly higher in GG than NG. On April 11, 2011, the eggplant/garlic co-growth stage, the available nitrogen content in GG was 76.30 mg·kg−1, significantly higher than 61.95 mg·kg−1 in NG. For available potassium on April 17, 2012, they were 398.48 and 387.97 mg·kg−1 in NG and GG, both were significantly higher than 314.84 mg·kg−1 in CK; (3) the soil pH showed a significantly higher level in NG treatment, but lower in GG treatment compared with CK. For the last samples in 2012, soil pH in NG and GG were 7.70 and 7.46, the highest and lowest one among them; (4) the alkaline phosphatase activity and pH displayed a similar decreasing trend with continuous cropping. These findings indicate that relay intercropping eggplant with garlic could be an ideal farming system to effectively improve soil nutrient content, increase soil fertility, and alleviate soil sickness to some extent. These findings are important in helping to develop sustainable eggplant production. PMID:25340875

  10. The mormyrid brainstem--II. The medullary electromotor relay nucleus: an ultrastructural horseradish peroxidase study.

    PubMed

    Elekes, K; Ravaille, M; Bell, C C; Libouban, S; Szabo, T

    1985-06-01

    The medullary relay nucleus of the mormyrid weakly electric fish Gnathonemus petersii is a stage in the command pathway for the electric organ discharge. It receives input from the presumed command or pacemaker nucleus and projects to the electromotoneurons in the spinal cord. Its fine structure and synaptology were investigated by electron microscopy. The origin of the terminals contacting the cell membrane of the neurons of this nucleus was determined by horseradish peroxidase (HRP) injections into different brain structures, namely into the bulbar command- and mesencephalic command-associated nuclei. Twenty-five to thirty large cells of about 45 micron in diameter constitute the medullary electromotor relay. Each cell has a kidney-shaped, lobulated nucleus, a large myelinated axon with a short initial segment and several long, richly arborizing primary dendrites. Many, if not all, cells are interconnected with large somatosomatic or dendrosomatic, dendrodendritic and dendroaxonic gap junctions. These junctions often occur in serial or triadic arrangements. The relay cells receive large club endings as well as small boutons. The club endings are found mainly on the soma and primary dendrites and are morphologically mixed synapses. The boutons are characterized by synapses which are only chemical and are distributed all over the cell membrane, but with a definitely higher frequency on secondary dendrites and more distal parts of dendritic processes. Horseradish peroxidase injections into the mesencephalic command-associated nucleus reveal a large number of labelled boutons on the secondary dendrites of the relay cells. Injections into the bulbar command-associated nucleus label the same type of boutons as mesencephalic injections, but also label club endings on relay cell soma and primary dendrites. The results support the conclusion made on the basis of previous light microscopical observations that boutons originate from the bulbar command-associated nucleus

  11. Soil chemical property changes in eggplant/garlic relay intercropping systems under continuous cropping.

    PubMed

    Wang, Mengyi; Wu, Cuinan; Cheng, Zhihui; Meng, Huanwen; Zhang, Mengru; Zhang, Hongjing

    2014-01-01

    Soil sickness is a critical problem for eggplant (Solanum melongena L.) under continuous cropping that affects sustainable eggplant production. Relay intercropping is a significant technique on promoting soil quality, improving eco-environment, and raising output. Field experiments were conducted from September 2010 to November 2012 in northwest China to determine the effects of relay intercropping eggplant with garlic (Allium sativum L.) on soil enzyme activities, available nutrient contents, and pH value under a plastic tunnel. Three treatments were in triplicate using randomized block design: eggplant monoculture (CK), eggplant relay intercropping with normal garlic (NG) and eggplant relay intercropping with green garlic (GG). The major results are as follows: (1) the activities of soil invertase, urease, and alkaline phosphatase were generally enhanced in NG and GG treatments; (2) relay intercropping significantly increased the soil available nutrient contents, and they were mostly higher in GG than NG. On April 11, 2011, the eggplant/garlic co-growth stage, the available nitrogen content in GG was 76.30 mg·kg(-1), significantly higher than 61.95 mg·kg(-1) in NG. For available potassium on April 17, 2012, they were 398.48 and 387.97 mg·kg(-1) in NG and GG, both were significantly higher than 314.84 mg·kg(-1) in CK; (3) the soil pH showed a significantly higher level in NG treatment, but lower in GG treatment compared with CK. For the last samples in 2012, soil pH in NG and GG were 7.70 and 7.46, the highest and lowest one among them; (4) the alkaline phosphatase activity and pH displayed a similar decreasing trend with continuous cropping. These findings indicate that relay intercropping eggplant with garlic could be an ideal farming system to effectively improve soil nutrient content, increase soil fertility, and alleviate soil sickness to some extent. These findings are important in helping to develop sustainable eggplant production.

  12. Outage Performance of Cooperative Relay Selection with Multiple Source and Destination Antennas over Dissimilar Nakagami-m Fading Channels

    NASA Astrophysics Data System (ADS)

    Lee, Wooju; Yoon, Dongweon

    Cooperative relay selection, in which one of multiple relays is selected to retransmit the source signal to the destination, has received considerable attention in recent years, because it is a simple way to obtain cooperative diversity in wireless networks. The exact expression of outage probability for a decode-and-forward cooperative relay selection with multiple source and destination antennas over Rayleigh fading channels was recently derived in [9]. In this letter, we derive the exact expressions of outage probability and diversity-multiplexing tradeoff over independent and non-identically distributed Nakagami-m fading channels as an extension of [9]. We then analyze the effects of various parameters such as fading conditions, number of relays, and number of source and destination antennas on the outage probability.

  13. 75 FR 26701 - Telecommunications Relay Services and Speech-to-Speech Services for Individuals With Hearing and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-12

    ...; DA 10-761] Telecommunications Relay Services and Speech-to-Speech Services for Individuals With Hearing and Speech Disabilities AGENCY: Federal Communications Commission. ACTION: Proposed rule. SUMMARY.... The Bureau seeks comment on NECA's proposed compensation rates for Interstate TRS,...

  14. Outage Analysis of Dual-hop Cognitive Networks with Relay Selection over Nakagami-m Fading Environment

    NASA Astrophysics Data System (ADS)

    Zhang, Zongsheng; Pi, Xurong

    2014-09-01

    In this paper, we investigate the outage performance of decode-and-forward cognitive relay networks for Nakagami-m fading channels, with considering both best relay selection and interference constraints. Focusing on the relay selection and making use of the underlay cognitive approach, an exact closed-form outage probability expression is derived in an independent, non-identical distributed Nakagami-m environment. The closed-form outage probability provides an efficient means to evaluate the effects of the maximum allowable interference power, number of cognitive relays, and channel conditions between the primary user and cognitive users. Finally, we present numerical results to validate the theory analysis. Moreover, from the simulation results, we obtain that the system can obtain the full diversity.

  15. Modeling the efficiency of Förster resonant energy transfer from energy relay dyes in dye-sensitized solar cells.

    PubMed

    Hoke, Eric T; Hardin, Brian E; McGehee, Michael D

    2010-02-15

    Förster resonant energy transfer can improve the spectral breadth, absorption and energy conversion efficiency of dye sensitized solar cells. In this design, unattached relay dyes absorb the high energy photons and transfer the excitation to sensitizing dye molecules by Förster resonant energy transfer. We use an analytic theory to calculate the excitation transfer efficiency from the relay dye to the sensitizing dye accounting for dynamic quenching and relay dye diffusion. We present calculations for pores of cylindrical and spherical geometry and examine the effects of the Förster radius, the pore size, sensitizing dye surface concentration, collisional quenching rate, and relay dye lifetime. We find that the excitation transfer efficiency can easily exceed 90% for appropriately chosen dyes and propose two different strategies for selecting dyes to achieve record power conversion efficiencies.

  16. Tracking and Pointing of Target by a Bifocal Relay Mirror Spacecraft Using Attitude Control and Fast Steering Mirrors Tilting

    DTIC Science & Technology

    2002-08-01

    proposed for the tracking and pointing of the target of the Bifocal Relay Mirror. The attitude control system consists of reaction wheels , star trackers and...nautics, Inc. with permission. T Transmitter portion of the spacecraft w Reaction wheel m Mirror rel Relative B Acronyms BRM Bifocal Relay Mirror...tem are respectively OR and OS . The other bodies considered in the dynamic model are: • four reaction wheels mounted in tetrahedral configuration on

  17. Ru(II)/Organo Relay Catalytic Three-Component Reaction of 3-Diazooxindoles, Amines, and Nitroalkene: Formal Synthesis of (-)-Psychotrimine.

    PubMed

    Lian, Xiao-Lei; Meng, Jing; Han, Zhi-Yong

    2016-09-02

    A highly enantioselective carbenoid-associated N-H functionalization/Michael addition cascade reaction is developed by virtue of Ru(II)/chiral organo bifunctional catalyst relay catalysis. In this way, a variety of optically pure 3-amino-3-alkyloxindoles can be easily achieved. Moreover, on the basis of this metal/organo relay catalytic three-component protocol, a key intermediate for the formal synthesis of (-)-psychotrimine could be obtained in six steps with 25% overall yield.

  18. Tracking and Data Relay Satellite System user impact and network compatibility study. [antenna design and telecommunication links

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The report contains data on antenna configurations for the low data rate users of the Tracking and Data Relay Satellite System (TDRSS). It treats the coverage and mutual visibility considerations between the user satellites and the relay satellites and relates these considerations to requirements of antenna beamwidth and fractional user orbital coverage. A final section includes user/TDRS telecommunication link budgets and forward and return link data rate tradeoffs.

  19. High salinity relay as a postharvest processing strategy to reduce vibrio vulnificus levels in Chesapeake Bay oysters (Crassostrea virginica).

    PubMed

    Audemard, Corinne; Kator, Howard I; Rhodes, Martha W; Gallivan, Thomas; Erskine, A J; Leggett, A Thomas; Reece, Kimberly S

    2011-11-01

    In 2009 the U.S. Food and Drug Administration (FDA) announced its intention to implement postharvest processing (PHP) methods to eliminate Vibrio vulnificus from oysters intended for the raw, half-shell market that are harvested from the Gulf of Mexico during warmer months. FDA-approved PHP methods can be expensive and may be associated with unfavorable responses from some consumers. A relatively unexplored PHP method that uses relaying to high salinity waters could be an alternative strategy, considering that high salinities appear to negatively affect the survival of V. vulnificus. During relay, however, oysters may be exposed to rapid and large salinity increases that could cause increased mortality. In this study, the effectiveness of high salinity relay to reduce V. vulnificus to <30 most probable number (MPN) per g and the impact on oyster mortality were assessed in the lower Chesapeake Bay. Two relay experiments were performed during the summer and fall of 2010. Oysters collected from three grow-out sites, a low salinity site (14 to 15 practical salinity units [psu]) and two moderate salinity sites (22 to 25 psu), were relayed directly to a high salinity site (≥30 psu) on Virginia's Eastern Shore. Oysters were assayed for V. vulnificus and Vibrio parahaemolyticus (another Vibrio species of concern) densities at time 0 prior to relay and after 7 and 14 days of relay, using the FDA MPN enrichment method combined with detection by real-time PCR. After 14 days, both V. vulnificus and V. parahaemolyticus densities were ≤0.8 MPN/g, and decreases of 2 to 3 log in V. vulnificus densities were observed. Oyster mortalities were low (≤4%) even for oysters from the low salinity harvest site, which experienced a salinity increase of approximately 15 psu. Results, although preliminary and requiring formal validation and economic analysis, suggest that high salinity relay could be an effective PHP method.

  20. Programming A Molecular Relay for Ultrasensitive Biodetection through 129 Xe NMR

    SciTech Connect

    Wang, Yanfei; Roose, Benjamin W.; Philbin, John P.; Doman, Jordan L.; Dmochowski, Ivan J.

    2015-12-21

    We reported a supramolecular strategy for detecting specific proteins in complex media by using hyperpolarized 129Xe NMR. A cucurbit[6]uril (CB[6])-based molecular relay was programmed for three sequential equilibrium conditions by designing a two-faced guest (TFG) that initially binds CB[6] and blocks the CB[6]–Xe interaction. Moreover, the protein analyte recruits the TFG and frees CB[6] for Xe binding. TFGs containing CB[6]- and carbonic anhydrase II (CAII)-binding domains were synthesized in one or two steps. X-ray crystallography confirmed TFG binding to Zn2+ in the deep CAII active-site cleft, which precludes simultaneous CB[6] binding. The molecular relay was reprogrammed to detect avidin by using a different TFG. Finally, Xe binding by CB[6] was detected in buffer and in E. coli cultures expressing CAII through ultrasensitive 129Xe NMR spectroscopy.