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 contacts...

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 contacts...

47 CFR 78.27 - License conditions.

Code of Federal Regulations, 2010 CFR

2010-10-01

..., modifications, assignments or transfers of control, and renewals) in the Cable Television Relay Service to serve cable television systems and other eligible systems, shall contain the condition that cable television... Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES CABLE TELEVISION RELAY...

47 CFR 78.27 - License conditions.

Code of Federal Regulations, 2012 CFR

2012-10-01

..., modifications, assignments or transfers of control, and renewals) in the Cable Television Relay Service to serve cable television systems and other eligible systems, shall contain the condition that cable television... Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES CABLE TELEVISION RELAY...

47 CFR 78.27 - License conditions.

Code of Federal Regulations, 2011 CFR

2011-10-01

..., modifications, assignments or transfers of control, and renewals) in the Cable Television Relay Service to serve cable television systems and other eligible systems, shall contain the condition that cable television... Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES CABLE TELEVISION RELAY...

47 CFR 78.27 - License conditions.

Code of Federal Regulations, 2014 CFR

2014-10-01

..., modifications, assignments or transfers of control, and renewals) in the Cable Television Relay Service to serve cable television systems and other eligible systems, shall contain the condition that cable television... Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES CABLE TELEVISION RELAY...

47 CFR 78.27 - License conditions.

Code of Federal Regulations, 2013 CFR

2013-10-01

..., modifications, assignments or transfers of control, and renewals) in the Cable Television Relay Service to serve cable television systems and other eligible systems, shall contain the condition that cable television... Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES CABLE TELEVISION RELAY...

Protective and control relays as coal-mine power-supply ACS subsystem

NASA Astrophysics Data System (ADS)

Kostin, V. N.; Minakova, T. E.

2017-10-01

The paper presents instantaneous selective short-circuit protection for the cabling of the underground part of a coal mine and central control algorithms as a Coal-Mine Power-Supply ACS Subsystem. In order to improve the reliability of electricity supply and reduce the mining equipment down-time, a dual channel relay protection and central control system is proposed as a subsystem of the coal-mine power-supply automated control system (PS ACS).

GPS/REFSAT definition study report for low-cost terminals

NASA Technical Reports Server (NTRS)

1980-01-01

A relay transponder, located either on a satellite in geostationary orbit or on a local tower to relay acquisition-aiding data, ephemerides, etc, from a ground-based remote control station to a GPS civil user terminal located on a ship or land-transportation vehicle is described. Termed REFSAT (Reference Satellite), this concept reduces the circuit complexity and cost of user terminals. The various systems needed to implement the REFSAT concept for low-cost, GPS civil terminals are defined. The GPS/REFSAT system compatible with the NAVSTAR GPS system consists of a geostationary relay satellite, civil user terminals, and the central facility which performs operations common to all users for relay via the space segment. A GPS/REFSAT system utilizing a local tower for the relay transponder is described, results of a study of civil user requirements are presented, and specifications for the GPS/REFSAT system and its individual segments are included.

Development of Hardware-in-the-loop Microgrid Testbed

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xiao, Bailu; Prabakar, Kumaraguru; Starke, Michael R

2015-01-01

A hardware-in-the-loop (HIL) microgrid testbed for the evaluation and assessment of microgrid operation and control system has been presented in this paper. The HIL testbed is composed of a real-time digital simulator (RTDS) for modeling of the microgrid, multiple NI CompactRIOs for device level control, a prototype microgrid energy management system (MicroEMS), and a relay protection system. The applied communication-assisted hybrid control system has been also discussed. Results of function testing of HIL controller, communication, and the relay protection system are presented to show the effectiveness of the proposed HIL microgrid testbed.

Relay Protection and Automation Systems Based on Programmable Logic Integrated Circuits

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lashin, A. V., E-mail: LashinAV@lhp.ru; Kozyrev, A. V.

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.

Multistability and hidden attractors in a relay system with hysteresis

NASA Astrophysics Data System (ADS)

Zhusubaliyev, Zhanybai T.; Mosekilde, Erik; Rubanov, Vasily G.; Nabokov, Roman A.

2015-06-01

For nonlinear dynamic systems with switching control, the concept of a "hidden attractor" naturally applies to a stable dynamic state that either (1) coexists with the stable switching cycle or (2), if the switching cycle is unstable, has a basin of attraction that does not intersect with the neighborhood of that cycle. We show how the equilibrium point of a relay system disappears in a boundary-equilibrium bifurcation as the system enters the region of autonomous switching dynamics and demonstrate experimentally how a relay system can exhibit large amplitude chaotic oscillations at high values of the supply voltage. By investigating a four-dimensional model of the experimental relay system we finally show how a variety of hidden periodic, quasiperiodic and chaotic attractors arise, transform and disappear through different bifurcations.

Commercial Grade Item (CGI) Dedication for Leak Detection Relays

DOE Office of Scientific and Technical Information (OSTI.GOV)

KOCH, M.R.; JOHNS, B.R.

1999-12-21

This Test Plan provides a test method to dedicate the leak detection relays used on the new Pumping and Instrumentation Control (PIC) skids. The new skids are fabricated on-site. The leak detection system is a safety class system per the Authorization Basis.

Commercial Grade Item (CGI) Dedication for Leak Detection Relays

DOE Office of Scientific and Technical Information (OSTI.GOV)

KOCH, M.R.

2000-02-28

This Test Plan provides a test method to dedicate the leak detection relays used on the new Pumping Instrumentation and Control (PIC) skids. The new skids are fabricated on-site. The leak detection system is a safety class system per the Authorization Basis.

Commercial Grade Item (CGI) Dedication for Leak Detection Relays

DOE Office of Scientific and Technical Information (OSTI.GOV)

KOCH, M.R.

1999-08-11

This Test Plan provides a test method to dedicate the leak detection relays used on the new Pumping and Instrumentation Control (PIC) skids. The new skids are fabricated on-site. The leak detection system is a safety class system per the Authorization Basis.

Commercial Grade Item (CGI) Dedication for Leak Detection Relays

DOE Office of Scientific and Technical Information (OSTI.GOV)

JOHNS, B.R.

1999-05-05

This Test Plan provides a test method to dedicate the leak detection relays used on the new Pumping and Instrumentation Control (PIC) skids. The new skids are fabricated on-site. The leak detection system is a safety class system per the Authorization Basis.

Commercial Grade Item (CGI) Dedication for Leak Detection Relays

DOE Office of Scientific and Technical Information (OSTI.GOV)

KOCH, M.R.

1999-10-26

This Test Plan provides a test method to dedicate the leak detection relays used on the new Pumping and Instrumentation Control (PIC) skids. The new skids are fabricated on-site. The leak detection system is a safety class system per the Authorization Basis.

Commercial Grade Item (CGI) Dedication for Leak Detection Relays

DOE Office of Scientific and Technical Information (OSTI.GOV)

JOHNS, B.R.; KOCH, M.R.

2000-01-28

This Test Plan provides a test method to dedicate the leak detection relays used on the new Pumping Instrumentation and Control (PIC) skids. The new skids are fabricated on-site. The leak detection system is a safety class system per the Authorization Basis.

Modeling and control of non-square MIMO system using relay feedback.

PubMed

Kalpana, D; Thyagarajan, T; Gokulraj, N

2015-11-01

This paper proposes a systematic approach for the modeling and control of non-square MIMO systems in time domain using relay feedback. Conventionally, modeling, selection of the control configuration and controller design of non-square MIMO systems are performed using input/output information of direct loop, while the output of undesired responses that bears valuable information on interaction among the loops are not considered. However, in this paper, the undesired response obtained from relay feedback test is also taken into consideration to extract the information about the interaction between the loops. The studies are performed on an Air Path Scheme of Turbocharged Diesel Engine (APSTDE) model, which is a typical non-square MIMO system, with input and output variables being 3 and 2 respectively. From the relay test response, the generalized analytical expressions are derived and these analytical expressions are used to estimate unknown system parameters and also to evaluate interaction measures. The interaction is analyzed by using Block Relative Gain (BRG) method. The model thus identified is later used to design appropriate controller to carry out closed loop studies. Closed loop simulation studies were performed for both servo and regulatory operations. Integral of Squared Error (ISE) performance criterion is employed to quantitatively evaluate performance of the proposed scheme. The usefulness of the proposed method is demonstrated on a lab-scale Two-Tank Cylindrical Interacting System (TTCIS), which is configured as a non-square system. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

Aerial Networking for the Implementation of Cooperative Control on Small Unmanned Aerial Systems

DTIC Science & Technology

2013-03-01

the relay aircraft to an optimal location. Secondly, a mesh network was configured and tested. This configuration successfully relayed aircraft...functionality, such as updating navigation waypoints to each aircraft. The results suggest the system be updated with more capable modems in a mesh ...

Dilution cycle control for an absorption refrigeration system

DOEpatents

Reimann, Robert C.

1984-01-01

A dilution cycle control system for an absorption refrigeration system is disclosed. The control system includes a time delay relay for sensing shutdown of the absorption refrigeration system and for generating a control signal only after expiration of a preselected time period measured from the sensed shutdown of the absorption refrigeration system, during which the absorption refrigeration system is not restarted. A dilution cycle for the absorption refrigeration system is initiated in response to generation of a control signal by the time delay relay. This control system is particularly suitable for use with an absorption refrigeration system which is frequently cycled on and off since the time delay provided by the control system prevents needless dilution of the absorption refrigeration system when the system is turned off for only a short period of time and then is turned back on.

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.

Commercial grade item (CGI) dedication of MDR relays for nuclear safety related applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Das, R.K.; Julka, A.; Modi, G.

1994-08-01

MDR relays manufactured by Potter and Brumfield (P and B) have been used in various safety related applications in commercial nuclear power plants. These include emergency safety features (ESF) actuation systems, emergency core cooling systems (ECCS) actuation, and reactor protection systems. The MDR relays manufactured prior to May 1990 showed signs of generic failure due to corrosion and outgassing of coil varnish. P and B has made design changes to correct these problems in relays manufactured after May 1990. However, P and B does not manufacture the relays under any 10CFR50 Appendix B quality assurance (QA) program. They manufacture themore » relays under their commercial QA program and supply these as commercial grade items. This necessitates CGI Dedication of these relays for use in nuclear-safety-related applications. This paper presents a CGI dedication program that has been used to dedicate the MDR relays manufactured after May 1990. The program is in compliance with current Nuclear Regulatory Commission (NRC) and Electric Power Research Institute (EPRI) guidelines and applicable industry standards; it specifies the critical characteristics of the relays, provides the tests and analysis required to verify the critical characteristics, the acceptance criteria for the test results, performs source verification to qualify P and B for its control of the critical characteristics, and provides documentation. The program provides reasonable assurance that the new MDR relays will perform their intended safety functions.« less

Transformational Communications Architecture for the Unit Operations Center (UOC); Common Aviation Command and Control System (CAC2S); and Command and Control On-the-Move Network, Digital Over-the-Horizon Relay (CONDOR)

DTIC Science & Technology

2004-06-01

CAPABILITY SETS..............................................................................11 Figure 6. T3 DESIGN ...Radio System (JTRS) in 2008 and beyond. JTRS is being designed to provide a flexible new approach to meet diverse warfighter communications needs...Command and Control On-the-Move Network, Digital Over the Horizon Relay (CoNDOR) The CoNDOR Capability Set is an Architectural Approach designed to

Solid state power controllers

NASA Technical Reports Server (NTRS)

Gibbs, R. S.

1973-01-01

The rationale, analysis, design, breadboarding and testing of the incremental functional requirements are reported that led to the development of prototype 1 and 5 Amp dc and 1 Amp ac solid state power controllers (SSPC's). The SSPC's are to be considered for use as a replacement of electro-mechanical relays and circuit breakers in future spacecraft and aircraft. They satisfy the combined function of both the relay and circuit breaker and can be remotely controlled by small signals, typically 10 mA, 5 to 28 Vdc. They have the advantage over conventional relay/circuit breaker systems in that they can be located near utilization equipment and the primary ac or dc bus. The low level control, trip indication and status signals can be circuited by small guage wire for control, computer interface, logic, electrical multiplexing, unboard testing, and power management and distribution purposes. This results in increased system versatility at appreciable weight saving and increased reliability.

Prescription and over-the-counter medications tool kit.

DOT National Transportation Integrated Search

2011-04-01

Automatic vehicle location (AVL) is a computer-based vehicle tracking system. For transit, the actual real-time position of each vehicle is measured and its location is relayed to a control center. Actual position determination and relay techniques v...

Space-based solar power conversion and delivery systems study. Volume 2: Engineering analysis of orbital systems

NASA Technical Reports Server (NTRS)

1976-01-01

Program plans, schedules, and costs are determined for a synchronous orbit-based power generation and relay system. Requirements for the satellite solar power station (SSPS) and the power relay satellite (PRS) are explored. Engineering analysis of large solar arrays, flight mechanics and control, transportation, assembly and maintenance, and microwave transmission are included.

Tracking and data relay satellite system: NASA's new spacecraft data acquisition system

NASA Astrophysics Data System (ADS)

Schneider, W. C.; Garman, A. A.

The growth in NASA's ground network complexity and cost triggered a search for an alternative. Through a lease service contract, Western Union will provide to NASA 10 years of space communications services with a Tracking and Data Relay Satellite System (TDRSS). A constellation of four operating satellites in geostationary orbit and a single ground terminal will provide complete tracking, telemetry and command service for all of NASA's Earth orbital satellites below an altitude of 12,000 km. The system is shared: two satellites will be dedicated to NASA service; a third will provide backup as a shared spare; the fourth satellite will be dedicated to Western Union's Advanced Westar commercial service. Western Union will operate the ground terminal and provide operational satellite control. NASA's Network Control Center will provide the focal point for scheduling user services and controlling the interface between TDRSS and the rest of the NASA communications network, project control centers and data processing facilities. TDRSS single access user spacecraft data systems should be designed for efficient time shared data relay support. Reimbursement policy and rate structure for non-NASA users are currently being developed.

The SAS-3 delayed command system

NASA Technical Reports Server (NTRS)

Hoffman, E. J.

1975-01-01

To meet the requirements arising from the increased complexity of the power, attitude control and telemetry systems, a full redundant high-performance control section with delayed command capability was designed for the Small Astronomy Satellite-3 (SAS-3). The relay command system of SAS-3 is characterized by 56 bystate relay commands, with capability for handling up to 64 commands in future versions. The 'short' data command service of SAS-1 and SAS-2 consisting of shifting 24-bit words to two users was expanded to five users and augmented with a 'long load' data command service (up to 4080 bits) used to program the telemetry system and the delayed command subsystem. The inclusion of a delayed command service ensures a program of up to 30 relay or short data commands to be loaded for execution at designated times. The design and system operation of the SAS-3 command section are analyzed, with special attention given to the delayed command subsystem.

Influence of Insulation Monitoring Devices on the Operation of DC Control Circuits

DOE Office of Scientific and Technical Information (OSTI.GOV)

Olszowiec, Piotr, E-mail: olpio@o2.pl

The insulation level of DC control circuits is an important safety-critical factor and, thus, should be subject to continuous and periodic monitoring. The methods used for monitoring the insulation in live circuits may, however, disturb the reliable operation of control relays. The risks of misoperation and failure to reset of relays posed by the operation of various insulation monitoring and fault location systems are evaluated.

Heavy Lift Helicopter Flight Control System. Volume III. Automatic Flight Control System Development and Feasibility Demonstration

DTIC Science & Technology

1977-09-01

vdI1 SCCLRITY CLASSIFICATIOlN OF THIS PAGE(When DMae ffnifod) Block 20 (Cont): ------ AFCS control laws are examined. Associated documents are: Volume I...both the HII gain and LO gain outputs. Both were traced to defective components. In the former, the HII gain output amplifier AR4 was replaced and in...the latter, a relay in the relay module was defective . 613 S. . ......-. . . 6.2.2.4 ExcessivC Time Lag During the BARO altitude hold evaluation, the

TDRSS data handling and management system study. Ground station systems for data handling and relay satellite control

NASA Technical Reports Server (NTRS)

1973-01-01

Results of a two-phase study of the (Data Handling and Management System DHMS) are presented. An original baseline DHMS is described. Its estimated costs are presented in detail. The DHMS automates the Tracking and Data Relay Satellite System (TDRSS) ground station's functions and handles both the forward and return link user and relay satellite data passing through the station. Direction of the DHMS is effected via a TDRSS Operations Control Central (OCC) that is remotely located. A composite ground station system, a modified DHMS (MDHMS), was conceptually developed. The MDHMS performs both the DHMS and OCC functions. Configurations and costs are presented for systems using minicomputers and midicomputers. It is concluded that a MDHMS should be configured with a combination of the two computer types. The midicomputers provide the system's organizational direction and computational power, and the minicomputers (or interface processors) perform repetitive data handling functions that relieve the midicomputers of these burdensome tasks.

Large Efficient Intelligent Heating Relay Station System

NASA Astrophysics Data System (ADS)

Wu, C. Z.; Wei, X. G.; Wu, M. Q.

2017-12-01

The design of large efficient intelligent heating relay station system aims at the improvement of the existing heating system in our country, such as low heating efficiency, waste of energy and serious pollution, and the control still depends on the artificial problem. In this design, we first improve the existing plate heat exchanger. Secondly, the ATM89C51 is used to control the whole system and realize the intelligent control. The detection part is using the PT100 temperature sensor, pressure sensor, turbine flowmeter, heating temperature, detection of user end liquid flow, hydraulic, and real-time feedback, feedback signal to the microcontroller through the heating for users to adjust, realize the whole system more efficient, intelligent and energy-saving.

Some optimal considerations in attitude control systems. [evaluation of value of relative weighting between time and fuel for relay control law

NASA Technical Reports Server (NTRS)

Boland, J. S., III

1973-01-01

The conventional six-engine reaction control jet relay attitude control law with deadband is shown to be a good linear approximation to a weighted time-fuel optimal control law. Techniques for evaluating the value of the relative weighting between time and fuel for a particular relay control law is studied along with techniques to interrelate other parameters for the two control laws. Vehicle attitude control laws employing control moment gyros are then investigated. Steering laws obtained from the expression for the reaction torque of the gyro configuration are compared to a total optimal attitude control law that is derived from optimal linear regulator theory. This total optimal attitude control law has computational disadvantages in the solving of the matrix Riccati equation. Several computational algorithms for solving the matrix Riccati equation are investigated with respect to accuracy, computational storage requirements, and computational speed.

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

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.

A new modelling and identification scheme for time-delay systems with experimental investigation: a relay feedback approach

NASA Astrophysics Data System (ADS)

Pandey, Saurabh; Majhi, Somanath; Ghorai, Prasenjit

2017-07-01

In this paper, the conventional relay feedback test has been modified for modelling and identification of a class of real-time dynamical systems in terms of linear transfer function models with time-delay. An ideal relay and unknown systems are connected through a negative feedback loop to bring the sustained oscillatory output around the non-zero setpoint. Thereafter, the obtained limit cycle information is substituted in the derived mathematical equations for accurate identification of unknown plants in terms of overdamped, underdamped, critically damped second-order plus dead time and stable first-order plus dead time transfer function models. Typical examples from the literature are included for the validation of the proposed identification scheme through computer simulations. Subsequently, the comparisons between estimated model and true system are drawn through integral absolute error criterion and frequency response plots. Finally, the obtained output responses through simulations are verified experimentally on real-time liquid level control system using Yokogawa Distributed Control System CENTUM CS3000 set up.

Model-based iterative learning control of Parkinsonian state in thalamic relay neuron

NASA Astrophysics Data System (ADS)

Liu, Chen; Wang, Jiang; Li, Huiyan; Xue, Zhiqin; Deng, Bin; Wei, Xile

2014-09-01

Although the beneficial effects of chronic deep brain stimulation on Parkinson's disease motor symptoms are now largely confirmed, the underlying mechanisms behind deep brain stimulation remain unclear and under debate. Hence, the selection of stimulation parameters is full of challenges. Additionally, due to the complexity of neural system, together with omnipresent noises, the accurate model of thalamic relay neuron is unknown. Thus, the iterative learning control of the thalamic relay neuron's Parkinsonian state based on various variables is presented. Combining the iterative learning control with typical proportional-integral control algorithm, a novel and efficient control strategy is proposed, which does not require any particular knowledge on the detailed physiological characteristics of cortico-basal ganglia-thalamocortical loop and can automatically adjust the stimulation parameters. Simulation results demonstrate the feasibility of the proposed control strategy to restore the fidelity of thalamic relay in the Parkinsonian condition. Furthermore, through changing the important parameter—the maximum ionic conductance densities of low-threshold calcium current, the dominant characteristic of the proposed method which is independent of the accurate model can be further verified.

The GRO remote terminal system

NASA Technical Reports Server (NTRS)

Zillig, David J.; Valvano, Joe

1994-01-01

In March 1992, NASA HQ challenged GSFC/Code 531 to propose a fast, low-cost approach to close the Tracking Data Relay Satellite System (TDRSS) Zone-of-Exclusion (ZOE) over the Indian Ocean in order to provide global communications coverage for the Compton Gamma Ray Observatory (GRO) spacecraft. GRO had lost its tape recording capability which limited its valuable science data return to real-time contacts with the TDRS-E and TDRS-W synchronous data relay satellites, yielding only approximately 62 percent of the possible data obtainable. To achieve global coverage, a TDRS spacecraft would have to be moved over the Indian Ocean out of line-of-sight control of White Sands Ground Terminal (WSGT). To minimize operations life cycle costs, Headquarters also set a goal for remote control, from the WSGT, of the overseas ground station which was required for direct communications with TDRS-1. On August 27, 1992, Code 531 was given the go ahead to implement the proposed GRO Relay Terminal System (GRTS). This paper describes the Remote Ground Relay Terminal (RGRT) which went operational at the Canberra Deep Space Communications Complex (CDSCC) in Canberra, Australia in December 1993 and is currently augmenting the TDRSS constellation in returning between 80-100 percent of GRO science data under the control of a single operator at WSGT.

Research on Fault Characteristics and Line Protections Within a Large-scale Photovoltaic Power Plant

NASA Astrophysics Data System (ADS)

Zhang, Chi; Zeng, Jie; Zhao, Wei; Zhong, Guobin; Xu, Qi; Luo, Pandian; Gu, Chenjie; Liu, Bohan

2017-05-01

Centralized photovoltaic (PV) systems have different fault characteristics from distributed PV systems due to the different system structures and controls. This makes the fault analysis and protection methods used in distribution networks with distributed PV not suitable for a centralized PV power plant. Therefore, a consolidated expression for the fault current within a PV power plant under different controls was calculated considering the fault response of the PV array. Then, supported by the fault current analysis and the on-site testing data, the overcurrent relay (OCR) performance was evaluated in the collection system of an 850 MW PV power plant. It reveals that the OCRs at downstream side on overhead lines may malfunction. In this case, a new relay scheme was proposed using directional distance elements. In the PSCAD/EMTDC, a detailed PV system model was built and verified using the on-site testing data. Simulation results indicate that the proposed relay scheme could effectively solve the problems under variant fault scenarios and PV plant output levels.

77 FR 9518 - Airworthiness Directives; The Boeing Company Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-17

...) Installation of New Relay and Wiring Bundle Within 72 months after the effective date of this AD: Change the... and temperature control system (CACTCS). This AD requires doing certain wiring changes, installing a new relay and necessary wiring in the CACTCS, and performing an operational test of the cooling pack...

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.

The National Aeronautics and Space Administration (NASA) Tracking and Data Relay Satellite System (TDRSS) program Economic and programmatic, considerations

NASA Technical Reports Server (NTRS)

Aller, R. O.

1985-01-01

The Tracking and Data Relay Satellite System (TDRSS) represents the principal element of a new space-based tracking and communication network which will support NASA spaceflight missions in low earth orbit. In its complete configuration, the TDRSS network will include a space segment consisting of three highly specialized communication satellites in geosynchronous orbit, a ground segment consisting of an earth terminal, and associated data handling and control facilities. The TDRSS network has the objective to provide communication and data relay services between the earth-orbiting spacecraft and their ground-based mission control and data handling centers. The first TDRSS spacecraft has been now in service for two years. The present paper is concerned with the TDRSS experience from the perspective of the various programmatic and economic considerations which relate to the program.

Tracking and data relay satellite fault isolation and correction using PACES: Power and attitude control expert system

NASA Technical Reports Server (NTRS)

Erikson, Carol-Lee; Hooker, Peggy

1989-01-01

The Power and Attitude Control Expert System (PACES) is an object oriented and rule based expert system which provides spacecraft engineers with assistance in isolating and correcting problems within the Power and Attitude Control Subsystems of the Tracking and Data Relay Satellites (TDRS). PACES is designed to act in a consultant role. It will not interface to telemetry data, thus preserving full operator control over spacecraft operations. The spacecraft engineer will input requested information. This information will include telemetry data, action being performed, problem characteristics, spectral characteristics, and judgments of spacecraft functioning. Questions are answered either by clicking on appropriate responses (for text), or entering numeric values. A context sensitive help facility allows access to additional information when the user has difficulty understanding a question or deciding on an answer. The major functionality of PACES is to act as a knowledge rich system which includes block diagrams, text, and graphics, linked using hypermedia techniques. This allows easy movement among pieces of the knowledge. Considerable documentation of the spacecraft Power and Attitude Control Subsystems is embedded within PACES. The development phase of TDRSS expert system technology is intended to provide NASA with the necessary expertise and capability to define requirements, evaluate proposals, and monitor the development progress of a highly competent expert system for NASA's Tracking and Data Relay Satellite Program.

Amplitude death induced by mixed attractive and repulsive coupling in the relay system

NASA Astrophysics Data System (ADS)

Zhao, Nannan; Sun, Zhongkui; Xu, Wei

2018-01-01

The amplitude death (AD) phenomenon is found in the relay system in the presence of the mixed couplings composed of attractive coupling and repulsive coupling. The generation mechanism of AD is revealed and shows that the middle oscillator achieving AD is a prerequisite to further suppress oscillation of the outermost oscillators for the paradigmatic Stuart-Landau and Rössler models. Moreover, regarding the Stuart-Landau relay system as a small motif of star network, we also observe that the mixed couplings can facilitate AD state of the whole network system. Particularly, the threshold of coupling strength is invariable with the change of network size. Our findings may shed a new insight to explore the effects of hybrid coupling on complex systems, also provide a new strategy to control dynamic behaviors in engineering science and neuroscience fields.

Integrated command, control, communication and computation system design study. Summary of tasks performed

NASA Technical Reports Server (NTRS)

1982-01-01

A summary of tasks performed on an integrated command, control, communication, and computation system design study is given. The Tracking and Data Relay Satellite System command and control system study, an automated real-time operations study, and image processing work are discussed.

Theoretical study of network design methodologies for the aerial relay system. [energy consumption and air traffic control

NASA Technical Reports Server (NTRS)

Rivera, J. M.; Simpson, R. W.

1980-01-01

The aerial relay system network design problem is discussed. A generalized branch and bound based algorithm is developed which can consider a variety of optimization criteria, such as minimum passenger travel time and minimum liner and feeder operating costs. The algorithm, although efficient, is basically useful for small size networks, due to its nature of exponentially increasing computation time with the number of variables.

Design study for LANDSAT D attitude control system

NASA Technical Reports Server (NTRS)

Iwens, R. P.; Bernier, G. E.; Hofstadter, R. F.

1976-01-01

A design and performance evaluation is presented for the LANDSAT D attitude control system (ACS). Control and configuration of the gimballed Ku-band antenna system for communication with the tracking and data relay satellite (TDRS). Control of the solar array drive considered part of the ACS is also addressed.

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. This software update is significant in that it provides the only centralized service for tactical request management available for relay missions.

Satellite Relay Telemetry of Seismic Data in Earthquake Prediction and Control

NASA Technical Reports Server (NTRS)

Jackson, W. H.; Eaton, J. P.

1971-01-01

The Satellite Telemetry Earthquake Monitoring Program was started 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 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. The principal advantages of the satellite relay system over commercial telephone or microwave systems were: (1) it could be made less prone to massive failure during a major earthquake; (2) it could be extended readily into undeveloped regions; and (3) it could provide flexible, uniform communications over large sections of major global tectonic zones. Fundamental characteristics of a communications system to cope with the large volume of raw data collected by a short-period seismograph network are discussed.

Versatile solid-state relay

NASA Technical Reports Server (NTRS)

Fox, D. A.

1977-01-01

Solid-state relay (SSR), containing multinode control logic, is operated as normally open, normally closed, or latched. Moreover several can be paralleled to form two-pole or double-throw relays. Versatile unit ends need to design custom control circuit for every relay application. Technique can be extended to incorporate selectable time delay, on operation or release, or pulsed output.

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.

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.

Wire Rope Failure on the Guppy Winch

NASA Technical Reports Server (NTRS)

Figert, John

2016-01-01

On January 6, 2016 at El Paso, the Guppy winch motor was changed. After completion of the operational checks, the load bar was being reinstalled on the cargo pallet when the motor control FORWARD relay failed in the energized position. The pallet was pinned at all locations (each pin has a load capacity of 16,000 lbs.) while the winch was running. The wire rope snapped before aircraft power could be removed. After disassembly, the fractured wire rope was shipped to ES4 lab for further characterization of the wire rope portion of the failure. The system was being operated without a clear understanding of the system capability and function. The proximate cause was the failure of the K48 -Forward Winch Control Relay in the energized position, which allowed the motor to continuously run without command from the hand controller, and operation of the winch system with both controllers connected to the system. This prevented the emergency stop feature on the hand controller from functioning as designed. An electrical checkout engineering work instruction was completed and identified the failed relay and confirmed the emergency stop only paused the system when the STOP button on both connected hand controllers were depressed simultaneously. The winch system incorporates a torque limiting clutch. It is suspected that the clutch did not slip and the motor did not stall or overload the current limiter. Aircraft Engineering is looking at how to change the procedures to provide a checkout of the clutch and set to a slip torque limit appropriate to support operations.

Formation Flying for Satellites and UAVs

NASA Technical Reports Server (NTRS)

Merrill, Garrick; Becker, Chris

2015-01-01

A formation monitoring and control system was developed utilizing mesh networking and decentralized control. Highlights of this system include low latency, seamless addition and removal of vehicles, network relay functionality, and the ability to run on a variety of hardware.

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.

A microcomputer-based testing station for dynamic and static testing of protective relay systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, W.J.; Li, R.J.; Gu, J.C.

1995-12-31

Dynamic and static relay performance testing before installation in the field is a subject of great interest to utility relay engineers. The common practice in utility testing of new relays is to put the new unit to be tested in parallel with an existing functioning relay in the system, wait until an actual transient occurs and then observe and analyze the performance of new relay. It is impossible to have a thorough test of the protective relay system through this procedure. An equipment, Microcomputer-Based Testing Station (or PC-Based Testing Station), that can perform both static and dynamic testing of themore » relay is described in this paper. The Power System Simulation Laboratory at the University of Texas at Arlington is a scaled-down, three-phase, physical power system which correlates well with the important components for a real power system and is an ideal facility for the dynamic and static testing of protective relay systems. A brief introduction to the configuration of this laboratory is presented. Test results of several protective functions by using this laboratory illustrate the usefulness of this test set-up.« less

47 CFR 74.635 - Unattended operation.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Stations § 74.635 Unattended operation. (a) TV relay stations, TV translator relay stations, TV STL... persons; (3) TV relay stations, TV STL stations, TV translator relay stations, and TV microwave booster... control point. Additionally, a TV translator relay station (and any associated TV microwave booster...

Cooling system for radiator and condenser of vehicles with an air conditioner and method of operating the same

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shimada, Y.; Obata, Y.; Takeoka, T.

1987-04-21

A cooling system is described for radiator and condenser of vehicles with an air conditioner having a first blower and a second blower for cooling the radiator and the condenser so as to cool the engine cooling water and so as to condense the coolant, and a cooling cycle operation switch which comprises: (a) engine cooling water temperature switch (SW1) connected between a power supply and the first blower and turned on and off in accordance with high and low temperature conditions of the engine cooling water; (b) relay switching means for controlling the first and second blowers in accordancemore » with the on-off conditions of the cooling cycle operation switch; and (c) a control circuit having an on-off switch and a solenoid and connected between the relay switching means and either the first blower or the second blower, the solenoid of the control circuit being connected to switches (SW3, SW4 and SW5) for electrical equipment such as headlights, wipers; whereby, when any one of the switches for the electrical equipment of the vehicle is turned off, the first and second blowers are operated at normal speed through the relay switching means and the control circuit, upon the operation of the cooling cycle operation switch, while when any one of the switches for the electrical equipment is turned on, the first blower is on-off controlled through the engine cooling water temperature switch (SW1) and the second blower remains operated through the relay switching means.« less

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.

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.

14. CONTROL PANELS, EAST SIDE, MAIN FLOOR: TO LEFT (ORIGINAL ...

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

14. CONTROL PANELS, EAST SIDE, MAIN FLOOR: TO LEFT (ORIGINAL EQUIPMENT): UPPER FOUR GLASS BOXES ARE OVERCURRENT PROTECTIVE RELAYS; MIDDLE FOUR GLASS BOXES CONTAIN TESTING SWITCHES; LOWER TWO BOXES ARE DG1 METERING CHART RECORDERS TO RIGHT (MODERN EQUIPMENT): UPPER FOUR BLACK BOXES ARE PROTECTIVE SERVICE RELAYS; MIDDLE FOUR BOXES CONTAIN TESTING SWITCHES; LARGE BOX BELOW HOUSES REMOTE METERING SYSTEM METAL CABINETS (LABELED L-2 & L-4) BELOW CONTAIN ORIGINAL POWER CIRCUIT BREAKERS - Bonneville Power Administration South Bank Substation, I-84, South of Bonneville Dam Powerhouse, Bonneville, Multnomah County, OR

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.

Relay tracking control for second-order multi-agent systems with damaged agents.

PubMed

Dong, Lijing; Li, Jing; Liu, Qin

2017-11-01

This paper investigates a situation where smart agents capable of sensory and mobility are deployed to monitor a designated area. A preset number of agents start tracking when a target intrudes this area. Some of the tracking agents are possible to be out of order over the tracking course. Thus, we propose a cooperative relay tracking strategy to ensure the successful tracking with existence of damaged agents. Relay means that, when a tracking agent quits tracking due to malfunction, one of the near deployed agents replaces it to continue the tracking task. This results in jump of tracking errors and dynamic switching of topology of the multi-agent system. Switched system technique is employed to solve this specific problem. Finally, the effectiveness of proposed tracking strategy and validity of the theoretical results are verified by conducting a numerical simulation. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

ESTL tracking and data relay satellite /TDRSS/ simulation system

NASA Technical Reports Server (NTRS)

Kapell, M. H.

1980-01-01

The Tracking Data Relay Satellite System (TDRSS) provides single access forward and return communication links with the Shuttle/Orbiter via S-band and Ku-band frequency bands. The ESTL (Electronic Systems Test Laboratory) at Lyndon B. Johnson Space Center (JSC) utilizes a TDRS satellite simulator and critical TDRS ground hardware for test operations. To accomplish Orbiter/TDRSS relay communications performance testing in the ESTL, a satellite simulator was developed which met the specification requirements of the TDRSS channels utilized by the Orbiter. Actual TDRSS ground hardware unique to the Orbiter communication interfaces was procured from individual vendors, integrated in the ESTL, and interfaced via a data bus for control and status monitoring. This paper discusses the satellite simulation hardware in terms of early development and subsequent modifications. The TDRS ground hardware configuration and the complex computer interface requirements are reviewed. Also, special test hardware such as a radio frequency interference test generator is discussed.

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.

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.

Adaptive transmission based on multi-relay selection and rate-compatible LDPC codes

NASA Astrophysics Data System (ADS)

Su, Hualing; He, Yucheng; Zhou, Lin

2017-08-01

In order to adapt to the dynamical changeable channel condition and improve the transmissive reliability of the system, a cooperation system of rate-compatible low density parity check (RC-LDPC) codes combining with multi-relay selection protocol is proposed. In traditional relay selection protocol, only the channel state information (CSI) of source-relay and the CSI of relay-destination has been considered. The multi-relay selection protocol proposed by this paper takes the CSI between relays into extra account in order to obtain more chances of collabration. Additionally, the idea of hybrid automatic request retransmission (HARQ) and rate-compatible are introduced. Simulation results show that the transmissive reliability of the system can be significantly improved by the proposed protocol.

A pseudo-noise transponder design for low data rate users of the tracking and data relay satellite system

NASA Technical Reports Server (NTRS)

Birch, J. N.

1971-01-01

A compromise optimum design for the low data rate users of the Tracking and Data Relay Satellite System (TDRSS) is presented. Design goals for the TDRSS are employed in this report to arrive at the transponder design. Multipath, R.F.I., antenna pattern anomolies, other user signals, and other definable degrading factors are included as trade-off parameters in the design. Synchronization, emergency voice, user stabilization, polarization diversity and error control coding are also considered and their impact on the transponder design is evaluated.

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

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.

Airborne relay-based regional positioning system.

PubMed

Lee, Kyuman; Noh, Hongjun; Lim, Jaesung

2015-05-28

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.

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

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

DTIC Science & Technology

2013-03-01

Unmanned Aircraft Systems Flight Plan that identified small unmanned aerial systems ( SUAS ) as “a profound technological...advances in small unmanned aerial systems ( SUAS ) cooperative control. The end state objective of the research effort was to flight test an autonomous...requirements were captured in the Unmanned Aircraft Systems Flight Plan . The flight plan

76 FR 58424 - Transmission Relay Loadability Reliability Standard

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-21

... Protection Systems 2. Protective relays are devices that detect and initiate the removal of faults [[Page... protective relay detects a fault on an element of the system under its protection, it sends a signal to an... distribution providers to set load-responsive phase protection relays according to specific criteria to ensure...

Navigation system and method

NASA Technical Reports Server (NTRS)

Taylor, R. E.; Sennott, J. W. (Inventor)

1984-01-01

In a global positioning system (GPS), such as the NAVSTAR/GPS system, wherein the position coordinates of user terminals are obtained by processing multiple signals transmitted by a constellation of orbiting satellites, an acquisition-aiding signal generated by an earth-based control station is relayed to user terminals via a geostationary satellite to simplify user equipment. The aiding signal is FSK modulated on a reference channel slightly offset from the standard GPS channel. The aiding signal identifies satellites in view having best geometry and includes Doppler prediction data as well as GPS satellite coordinates and identification data associated with user terminals within an area being served by the control station and relay satellite. The aiding signal significantly reduces user equipment by simplifying spread spectrum signal demodulation and reducing data processing functions previously carried out at the user terminals.

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.

Analytical Approaches for Identification and Representation of Critical Protection Systems in Transient Stability Studies

NASA Astrophysics Data System (ADS)

Hedman, Mojdeh Khorsand

After a major disturbance, the power system response is highly dependent on protection schemes and system dynamics. Improving power systems situational awareness requires proper and simultaneous modeling of both protection schemes and dynamic characteristics in power systems analysis tools. Historical information and ex-post analysis of blackouts reaffirm the critical role of protective devices in cascading events, thereby confirming the necessity to represent protective functions in transient stability studies. This dissertation is aimed at studying the importance of representing protective relays in power system dynamic studies. Although modeling all of the protective relays within transient stability studies may result in a better estimation of system behavior, representing, updating, and maintaining the protection system data becomes an insurmountable task. Inappropriate or outdated representation of the relays may result in incorrect assessment of the system behavior. This dissertation presents a systematic method to determine essential relays to be modeled in transient stability studies. The desired approach should identify protective relays that are critical for various operating conditions and contingencies. The results of the transient stability studies confirm that modeling only the identified critical protective relays is sufficient to capture system behavior for various operating conditions and precludes the need to model all of the protective relays. Moreover, this dissertation proposes a method that can be implemented to determine the appropriate location of out-of-step blocking relays. During unstable power swings, a generator or group of generators may accelerate or decelerate leading to voltage depression at the electrical center along with generator tripping. This voltage depression may cause protective relay mis-operation and unintentional separation of the system. In order to avoid unintentional islanding, the potentially mis-operating relays should be blocked from tripping with the use of out-of-step blocking schemes. Blocking these mis-operating relays, combined with an appropriate islanding scheme, help avoid a system wide collapse. The proposed method is tested on data from the Western Electricity Coordinating Council. A triple line outage of the California-Oregon Intertie is studied. The results show that the proposed method is able to successfully identify proper locations of out-of-step blocking scheme.

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.

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.

High power regenerative laser amplifier

DOEpatents

Miller, John L.; Hackel, Lloyd A.; Dane, Clifford B.; Zapata, Luis E.

1994-01-01

A regenerative amplifier design capable of operating at high energy per pulse, for instance, from 20-100 Joules, at moderate repetition rates, for instance from 5-20 Hertz is provided. The laser amplifier comprises a gain medium and source of pump energy coupled with the gain medium; a Pockels cell, which rotates an incident beam in response to application of a control signal; an optical relay system defining a first relay plane near the gain medium and a second relay plane near the rotator; and a plurality of reflectors configured to define an optical path through the gain medium, optical relay and Pockels cell, such that each transit of the optical path includes at least one pass through the gain medium and only one pass through the Pockels cell. An input coupler, and an output coupler are provided, implemented by a single polarizer. A control circuit coupled to the Pockels cell generates the control signal in timed relationship with the input pulse so that the input pulse is captured by the input coupler and proceeds through at least one transit of the optical path, and then the control signal is applied to cause rotation of the pulse to a polarization reflected by the polarizer, after which the captured pulse passes through the gain medium at least once more and is reflected out of the optical path by the polarizer before passing through the rotator again to provide an amplified pulse.

High power regenerative laser amplifier

DOEpatents

Miller, J.L.; Hackel, L.A.; Dane, C.B.; Zapata, L.E.

1994-02-08

A regenerative amplifier design capable of operating at high energy per pulse, for instance, from 20-100 Joules, at moderate repetition rates, for instance from 5-20 Hertz is provided. The laser amplifier comprises a gain medium and source of pump energy coupled with the gain medium; a Pockels cell, which rotates an incident beam in response to application of a control signal; an optical relay system defining a first relay plane near the gain medium and a second relay plane near the rotator; and a plurality of reflectors configured to define an optical path through the gain medium, optical relay and Pockels cell, such that each transit of the optical path includes at least one pass through the gain medium and only one pass through the Pockels cell. An input coupler, and an output coupler are provided, implemented by a single polarizer. A control circuit coupled to the Pockels cell generates the control signal in timed relationship with the input pulse so that the input pulse is captured by the input coupler and proceeds through at least one transit of the optical path, and then the control signal is applied to cause rotation of the pulse to a polarization reflected by the polarizer, after which the captured pulse passes through the gain medium at least once more and is reflected out of the optical path by the polarizer before passing through the rotator again to provide an amplified pulse. 7 figures.

Reliability Analysis of Differential Relay as Main Protection Transformer Using Fuzzy Logic Algorithm

NASA Astrophysics Data System (ADS)

Mulyadi, Y.; Sucita, T.; Sumarto; Alpani, M.

2018-02-01

Electricity supply demand is increasing every year. It makes PT. PLN (Persero) is required to provide optimal customer service and satisfaction. Optimal service depends on the performance of the equipment of the power system owned, especially the transformer. Power transformer is an electrical equipment that transforms electricity from high voltage to low voltage or vice versa. However, in the electrical power system, is inseparable from interference included in the transformer. But, the disturbance can be minimized by the protection system. The main protection transformer is differential relays. Differential relays working system using Kirchoff law where inflows equal outflows. If there are excessive currents that interfere then the relays will work. But, the relay can also experience decreased performance. Therefore, this final project aims to analyze the reliability of the differential relay on the transformer in three different substations. Referring to the standard applied by the transmission line protection officer, the differential relay shall have slope characteristics of 30% in the first slope and 80% in the second slope when using two slopes and 80% when using one slope with an instant time and the corresponding ratio. So, the results obtained on the Siemens differential release have a reliable slope characteristic with a value of 30 on the fuzzy logic system. In a while, ABB a differential relay is only 80% reliable because two experiments are not reliable. For the time, all the differential relays are instant with a value of 0.06 on the fuzzy logic system. For ratios, the differential relays ABB have a better value than others brand with a value of 151 on the fuzzy logic system.

75 FR 2591 - Petition for Waiver of Compliance

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-15

... on vital microprocessor-based systems. CSXT proposes to verify and test signal locking systems controlled by microprocessor-based equipment by use of alternative procedures every 4 years after initial... vital microprocessor-based systems. These systems utilize programmed logic equations in lieu of relays...

14 CFR 1215.102 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION TRACKING AND DATA RELAY SATELLITE SYSTEM.... The Tracking and Data Relay Satellite System including Tracking and Data Relay Satellites (TDRS), the... user ground system/TDRSS interface. (c) Bit stream. The digital electronic signals acquired by TDRSS...

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…

78 FR 4055 - Airworthiness Directives; The Boeing Company Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-18

...) Installation of New Relay and Wiring Bundle Change Within 24 months after the effective date of this AD: Change... requires installing a new relay and doing certain wiring changes of the entertainment control switch. We... proposed to require installing a new relay and doing certain wiring changes of the entertainment control...

Interferometer design and controls for pulse stacking in high power fiber lasers

NASA Astrophysics Data System (ADS)

Wilcox, Russell; Yang, Yawei; Dahlen, Dar; Xu, Yilun; Huang, Gang; Qiang, Du; Doolittle, Lawrence; Byrd, John; Leemans, Wim; Ruppe, John; Zhou, Tong; Sheikhsofla, Morteza; Nees, John; Galvanauskas, Almantas; Dawson, Jay; Chen, Diana; Pax, Paul

2017-03-01

In order to develop a design for a laser-plasma accelerator (LPA) driver, we demonstrate key technologies that enable fiber lasers to produce high energy, ultrafast pulses. These technologies must be scalable, and operate in the presence of thermal drift, acoustic noise, and other perturbations typical of an operating system. We show that coherent pulse stacking (CPS), which requires optical interferometers, can be made robust by image-relaying, multipass optical cavities, and by optical phase control schemes that sense pulse train amplitudes from each cavity. A four-stage pulse stacking system using image-relaying cavities is controlled for 14 hours using a pulse-pattern sensing algorithm. For coherent addition of simultaneous ultrafast pulses, we introduce a new scheme using diffractive optics, and show experimentally that four pulses can be added while a preserving pulse width of 128 fs.

LCTS on ALPHASAT and Sentinel 1a: in orbit status of the LEO to geo data relay system

NASA Astrophysics Data System (ADS)

Zech, H.; Heine, F.; Troendle, D.; Pimentel, P. M.; Panzlaff, K.; Motzigemba, M.; Meyer, R.; Philipp-May, S.

2017-11-01

The performance of sensors for Earth Observation Missions is constantly improving. This drives the need for a reliable, high-speed data transfer capability from a Low Earth Orbit (LEO) spacecraft (S/C) to ground. In addition, for the transfer of time-critical data to ground, a low latency between data generation in orbit and data reception at the respective mission control center is of high importance. Laser communication between Satellites for high data transmission in combination with a GEO data relay system for reducing the latency time addresses these requirements.

[Improvement of controlling system by a separated medical unit of special purpose].

PubMed

Shelepov, A M; Savchenko, I F; Zhidik, V V; Gogolevskiĭ, A S

2009-11-01

The article presents a variant securing of field treatment institutes by mobile command points in combination with creation of automated system of control of a separated medical unit of special purpose and improvement of communications devices, computing and relaying of data. Such improvement of system of control permits to solve governmental tasks and make decision more effective, spending less time.

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 previous work applying PS-based receiver is not optimal.

Spatially Controlled Relay Beamforming

NASA Astrophysics Data System (ADS)

Kalogerias, Dionysios

This thesis is about fusion of optimal stochastic motion control and physical layer communications. Distributed, networked communication systems, such as relay beamforming networks (e.g., Amplify & Forward (AF)), are typically designed without explicitly considering how the positions of the respective nodes might affect the quality of the communication. Optimum placement of network nodes, which could potentially improve the quality of the communication, is not typically considered. However, in most practical settings in physical layer communications, such as relay beamforming, the Channel State Information (CSI) observed by each node, per channel use, although it might be (modeled as) random, it is both spatially and temporally correlated. It is, therefore, reasonable to ask if and how the performance of the system could be improved by (predictively) controlling the positions of the network nodes (e.g., the relays), based on causal side (CSI) information, and exploitting the spatiotemporal dependencies of the wireless medium. In this work, we address this problem in the context of AF relay beamforming networks. This novel, cyber-physical system approach to relay beamforming is termed as "Spatially Controlled Relay Beamforming". First, we discuss wireless channel modeling, however, in a rigorous, Bayesian framework. Experimentally accurate and, at the same time, technically precise channel modeling is absolutely essential for designing and analyzing spatially controlled communication systems. In this work, we are interested in two distinct spatiotemporal statistical models, for describing the behavior of the log-scale magnitude of the wireless channel: 1. Stationary Gaussian Fields: In this case, the channel is assumed to evolve as a stationary, Gaussian stochastic field in continuous space and discrete time (say, for instance, time slots). Under such assumptions, spatial and temporal statistical interactions are determined by a set of time and space invariant parameters, which completely determine the mean and covariance of the underlying Gaussian measure. This model is relatively simple to describe, and can be sufficiently characterized, at least for our purposes, both statistically and topologically. Additionally, the model is rather versatile and there is existing experimental evidence, supporting its practical applicability. Our contributions are summarized in properly formulating the whole spatiotemporal model in a completely rigorous mathematical setting, under a convenient measure theoretic framework. Such framework greatly facilitates formulation of meaningful stochastic control problems, where the wireless channel field (or a function of it) can be regarded as a stochastic optimization surface.. 2. Conditionally Gaussian Fields, when conditioned on a Markovian channel state: This is a completely novel approach to wireless channel modeling. In this approach, the communication medium is assumed to behave as a partially observable (or hidden) system, where a hidden, global, temporally varying underlying stochastic process, called the channel state, affects the spatial interactions of the actual channel magnitude, evaluated at any set of locations in the plane. More specifically, we assume that, conditioned on the channel state, the wireless channel constitutes an observable, conditionally Gaussian stochastic process. The channel state evolves in time according to a known, possibly non stationary, non Gaussian, low dimensional Markov kernel. Recognizing the intractability of general nonlinear state estimation, we advocate the use of grid based approximate nonlinear filters as an effective and robust means for recursive tracking of the channel state. We also propose a sequential spatiotemporal predictor for tracking the channel gains at any point in time and space, providing real time sequential estimates for the respective channel gain map. In this context, our contributions are multifold. Except for the introduction of the layered channel model previously described, this line of research has resulted in a number of general, asymptotic convergence results, advancing the theory of grid-based approximate nonlinear stochastic filtering. In particular, sufficient conditions, ensuring asymptotic optimality are relaxed, and, at the same time, the mode of convergence is strengthened. Although the need for such results initiated as an attempt to theoretically characterize the performance of the proposed approximate methods for statistical inference, in regard to the proposed channel modeling approach, they turn out to be of fundamental importance in the areas of nonlinear estimation and stochastic control. The experimental validation of the proposed channel model, as well as the related parameter estimation problem, termed as "Markovian Channel Profiling (MCP)", fundamentally important for any practical deployment, are subject of current, ongoing research. Second, adopting the first of the two aforementioned channel modeling approaches, we consider the spatially controlled relay beamforming problem for an AF network with a single source, a single destination, and multiple, controlled at will, relay nodes. (Abstract shortened by ProQuest.).

A Low-Cost Electronic Solar Energy Control

ERIC Educational Resources Information Center

Blade, Richard A.; Small, Charles T.

1978-01-01

Describes the design of a low-cost electronic circuit to serve as a differential thermostat, to control the operation of a solar heating system. It uses inexpensive diodes for sensoring temperature, and a mechanical relay for a switch. (GA)

Torque control for electric motors

NASA Technical Reports Server (NTRS)

Bernard, C. A.

1980-01-01

Method for adjusting electric-motor torque output to accomodate various loads utilizes phase-lock loop to control relay connected to starting circuit. As load is imposed, motor slows down, and phase lock is lost. Phase-lock signal triggers relay to power starting coil and generate additional torque. Once phase lock is recoverd, relay restores starting circuit to its normal operating mode.

Investigation of a Nonlinear Control System

NASA Technical Reports Server (NTRS)

Flugge-Lotz, I; Taylor, C F; Lindberg, H E

1958-01-01

A discontinuous variation of coefficients of the differential equation describing the linear control system before nonlinear elements are added is studied in detail. The nonlinear feedback is applied to a second-order system. Simulation techniques are used to study performance of the nonlinear control system and to compare it with the linear system for a wide variety of inputs. A detailed quantitative study of the influence of relay delays and of a transport delay is presented.

Space and Missile Systems Center Standard: Parts, Materials, and Processes Control Program for Launch Vehicles -SMC-S-011 (2012)

DTIC Science & Technology

2012-07-03

Specification for MIL-PRF-39008 Resistor Fixed, Composition ( Insulated ), Established Reliability, General Specification for MIL-S-45743 Soldering, Manual...2.1.5 Prohibited Relays 1. Plug-in types 2. Solder-sealed relays 2.1.6 Prohibited Resistors 1. All hollow glass or hollow ceramic core devices 2...lowest maximum temperature. This may be the core material, the insulation of the magnet, etc. 2/ Current rating for each winding shall be less than

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 deenergized...

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 deenergized...

Engineering and Design: Control Stations and Control Systems for Navigation Locks and Dams

DTIC Science & Technology

1997-05-30

of human intelli- hypothetical lock and dam configurations. Finally, b. Terminology. (1) PLC system. The computer- based systems utilize special...electrical industry for industrial use. There- fore, for purposes of this document, a computer- based system is referred to as a PLC system. (2) Relay- based ...be custom made, because most of today’s control systems of any complexity are PLC - based , the standard size of a given motor starter cubicle is not

Application of programmable logic controllers to space simulation

NASA Technical Reports Server (NTRS)

Sushon, Janet

1992-01-01

Incorporating a state-of-the-art process control and instrumentation system into a complex system for thermal vacuum testing is discussed. The challenge was to connect several independent control systems provided by various vendors to a supervisory computer. This combination will sequentially control and monitor the process, collect the data, and transmit it to color a graphic system for subsequent manipulation. The vacuum system upgrade included: replacement of seventeen diffusion pumps with eight cryogenic pumps and one turbomolecular pump, replacing a relay based control system, replacing vacuum instrumentation, and upgrading the data acquisition system.

Cross-layer Joint Relay Selection and Power Allocation Scheme for Cooperative Relaying System

NASA Astrophysics Data System (ADS)

Zhi, Hui; He, Mengmeng; Wang, Feiyue; Huang, Ziju

2018-03-01

A novel cross-layer joint relay selection and power allocation (CL-JRSPA) scheme over physical layer and data-link layer is proposed for cooperative relaying system in this paper. Our goal is finding the optimal relay selection and power allocation scheme to maximize system achievable rate when satisfying total transmit power constraint in physical layer and statistical delay quality-of-service (QoS) demand in data-link layer. Using the concept of effective capacity (EC), our goal can be formulated into an optimal joint relay selection and power allocation (JRSPA) problem to maximize the EC when satisfying total transmit power limitation. We first solving optimal power allocation (PA) problem with Lagrange multiplier approach, and then solving optimal relay selection (RS) problem. Simulation results demonstrate that CL-JRSPA scheme gets larger EC than other schemes when satisfying delay QoS demand. In addition, the proposed CL-JRSPA scheme achieves the maximal EC when relay located approximately halfway between source and destination, and EC becomes smaller when the QoS exponent becomes larger.

Cooperative wireless network control based health and activity monitoring system.

PubMed

Prakash, R; Ganesh, A Balaji; Girish, Siva V

2016-10-01

A real-time cooperative communication based wireless network is presented for monitoring health and activity of an end-user in their environment. The cooperative communication offers better energy consumption and also an opportunity to aware the current location of a user non-intrusively. The link between mobile sensor node and relay node is dynamically established by using Received Signal Strength Indicator (RSSI) and Link Quality Indicator (LQI) based on adaptive relay selection scheme. The study proposes a Linear Acceleration based Transmission Power Decision Control (LA-TPDC) algorithm to further enhance the energy efficiency of cooperative communication. Further, the occurrences of false alarms are carefully prevented by introducing three stages of sequential warning system. The real-time experiments are carried-out by using the nodes, namely mobile sensor node, relay nodes and a destination node which are indigenously developed by using a CC430 microcontroller integrated with an in-built transceiver at 868 MHz. The wireless node performance characteristics, such as energy consumption, Signal-Noise ratio (SNR), Bit Error Rate (BER), Packet Delivery Ratio (PDR) and transmission offset are evaluated for all the participated nodes. The experimental results observed that the proposed linear acceleration based transmission power decision control algorithm almost doubles the battery life time than energy efficient conventional cooperative communication.

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.

Spreading Sequence System for Full Connectivity Relay Network

NASA Technical Reports Server (NTRS)

Kwon, Hyuck M. (Inventor); Pham, Khanh D. (Inventor); Yang, Jie (Inventor)

2018-01-01

Fully connected uplink and downlink fully connected relay network systems using pseudo-noise spreading and despreading sequences subjected to maximizing the signal-to-interference-plus-noise ratio. The relay network systems comprise one or more transmitting units, relays, and receiving units connected via a communication network. The transmitting units, relays, and receiving units each may include a computer for performing the methods and steps described herein and transceivers for transmitting and/or receiving signals. The computer encodes and/or decodes communication signals via optimum adaptive PN sequences found by employing Cholesky decompositions and singular value decompositions (SVD). The PN sequences employ channel state information (CSI) to more effectively and more securely computing the optimal sequences.

Tracking and data relay satellite system configuration and tradeoff study. Volume 1: Study summary

NASA Technical Reports Server (NTRS)

Hill, T. E.

1973-01-01

A study was conducted to determine the configuration and tradeoffs of a tracking and data relay satellite. The study emphasized the design of a three axis stabilized satellite and a telecommunications system optimized for support of low and medium data rate user spacecraft. Telecommunications support to low and high, or low medium, and high data rate users, considering launches with the Delta 2914, the Atlas/Centaur, and the space shuttle was also considered. The following subjects are presented: (1) launch and deployment profile, (2) spacecraft mechanical and structural design, (3) attitude stabilization and control subsystem, and (4) reliability analysis.

Diversity Order Analysis of Dual-Hop Relaying with Partial Relay Selection

NASA Astrophysics Data System (ADS)

Bao, Vo Nguyen Quoc; Kong, Hyung Yun

In this paper, we study the performance of dual hop relaying in which the best relay selected by partial relay selection will help the source-destination link to overcome the channel impairment. Specifically, closed-form expressions for outage probability, symbol error probability and achievable diversity gain are derived using the statistical characteristic of the signal-to-noise ratio. Numerical investigation shows that the system achieves diversity of two regardless of relay number and also confirms the correctness of the analytical results. Furthermore, the performance loss due to partial relay selection is investigated.

Electronic circuit provides accurate sensing and control of dc voltage

NASA Technical Reports Server (NTRS)

Loftus, W. D.

1966-01-01

Electronic circuit used relay coil to sense and control dc voltage. The control relay is driven by a switching transistor that is biased to cutoff for all input up to slightly less than the threshold level.

ITC/USA/'82; Proceedings of the International Telemetering Conference, San Diego, CA, September 28-30, 1982

NASA Astrophysics Data System (ADS)

The topics studied are related to customer-designed integrated circuits and silicon foundries, systems applications, recent developments in airborne telemetry hardware, optical communications, theoretical applications, stored data systems, digital communications-satellites and other systems, antenna systems and technology, the AF satellite control network, modems, telemetry standards, NASA Deep Space Network operations, and modems applicable to range telemetry and range data relay. Aspects of communication interoperability and transmission standards are considered along with subjects of magnetic tape rec/rep theory and technology, a satellite command and control panel, a computer automated ground station, STS communications, cryptography, RF systems, sensor unique data recovery techniques, software applications, multiplexer-demuliplexer, microprocessor applications, and communication relays. Attention is given to the U.S. Federal data encryption standard (DES), the impact of channel errors on data compression, the effect of premodulation filters on bit error rate performance, and power efficient optical communications for space applications. For individual items see A84-32402 to A84-32456

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.

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.

Sedimentary record of relay zone evolution, Central Corinth Rift (Greece): Role of fault propagation and structural inheritance.

NASA Astrophysics Data System (ADS)

Hemelsdaël, Romain; Ford, Mary; Meyer, Nicolas

2013-04-01

Relay zones along rift border fault systems form topographic lows that are considered to allow the transfer of sediment from the footwall into hanging wall depocentres. Present knowledge focuses on the modifications of drainage patterns and sediment pathways across relay zones, however their vertical motion during growth and interaction of faults segments is not well documented. 3D models of fault growth and linkage are also under debate. The Corinth rift (Greece) is an ideal natural laboratory for the study of fault system evolution. Fault activity and rift depocentres migrated northward during Pliocene to Recent N-S extension. We report on the evolution of a relay zone in the currently active southern rift margin fault system from Pleistocene to present-day. The relay zone lies between the E-W East Helike (EHF) and Derveni faults (DF) that lie just offshore and around the town of Akrata. During its evolution the relay zone captured the antecedent Krathis river which continued to deposit Gilbert-type deltas across the relay zone during fault interaction, breaching and post linkage phases. Moreover our work underlines the role that pre-existing structure in the location of the transfer zone. Offshore fault geometry and kinematics, and sediment distribution were defined by interpretation and depth conversion of high resolution seismic profiles (from Maurice Ewing 2001 geophysical survey). Early lateral propagation of the EHF is recorded by synsedimentary fault propagation folds while the DF records tilted block geometries since initiation. Within the relay zone beds are gradually tilted toward the basin before breaching. These different styles of deformation highlight mechanical contrasts and upper crustal partition associated with the development of the Akrata relay zone. Onshore detailed lithostratigraphy, structure and geomorphological features record sedimentation across the subsiding relay ramp and subsequent footwall uplift after breaching. The area is characterised by the successive deposition of the northward prograding Platanos Gilbert-type delta (Middle group; deposited in hangingwall of the Pirgaki-Mamoussia fault) and the NE to E prograding Akrata Gilbert-type delta (Upper group). The Akrata Gilbert-type delta records progressive rotation and lengthening of the relay ramp as the East Helike fault and Derveni fault propagated laterally (from around 0.8 Ma) and started to overlap. The relay ramp was then breached by the Krathis fault (around 0.45 Ma) and the latter reactivated a NW-SE oriented inherited structure. Onshore-offshore correlation and profile restoration of the Upper group demonstrate the presence of this pre-existing structure (detachment fault?) below the Akrata relay zone that was responsible for significant eastward thickening in early rift sediments (Lower to Middle group). Our evolution model is consistent with the 'isolated fault' model where a fault array initially develops from growth of kinematically independent fault segments and fault displacement gradually accumulates during pre- and post-linkage stages. Despite the prominent control of pre-existing fabrics on the location of the transfer zone, lateral fault propagation and interaction can be well documented.

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.

Application of Advanced Wide Area Early Warning Systems with Adaptive Protection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blumstein, Carl; Cibulka, Lloyd; Thorp, James

2014-09-30

Recent blackouts of power systems in North America and throughout the world have shown how critical a reliable power system is to modern societies, and the enormous economic and societal damage a blackout can cause. It has been noted that unanticipated operation of protection systems can contribute to cascading phenomena and, ultimately, blackouts. This project developed and field-tested two methods of Adaptive Protection systems utilizing synchrophasor data. One method detects conditions of system stress that can lead to unintended relay operation, and initiates a supervisory signal to modify relay response in real time to avoid false trips. The second methodmore » detects the possibility of false trips of impedance relays as stable system swings “encroach” on the relays’ impedance zones, and produces an early warning so that relay engineers can re-evaluate relay settings. In addition, real-time synchrophasor data produced by this project was used to develop advanced visualization techniques for display of synchrophasor data to utility operators and engineers.« less

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

Identification and Control of Non-Linear Time-Varying Dynamical Systems Using Artificial Neural Networks

DTIC Science & Technology

1992-09-01

finding an inverse plant such as was done by Bertrand [BD91] and by Levin, Gewirtzman and Inbar in a binary type inverse controller [LGI91], to self tuning...gain robust control. 2) Self oscillating adaptive controller. 3) Gain scheduling. 4) Self tuning. 5) Model-reference adaptive systems. Although the...of multidimensional systems (CS881 as well as aircraft [HG90]. The self oscillating method is also a feedback based mechanism, utilizing a relay in the

Grid Integrated Type 3 Wind Systems - Modeling, and Line Protection Performance Analysis using the RTDS

NASA Astrophysics Data System (ADS)

Jain, Rishabh

In this thesis, the line protection elements and their supervisory elements are analyzed in context of Type 3 (Doubly Fed Induction Generator based) grid integrated wind turbine systems. The underlying converter and controller design algorithms and topologies are discussed. A detailed controller for the Type 3 wind turbine system is designed and integrated to the grid using the RTDS. An alternative to the conventional PLL for tracking of rotor frequency is designed and implemented. A comparative analysis of the performance of an averaged model and the corresponding switching model is presented. After completing the WT model design, the averaged model is used to model an aggregate 10-generator equivalent model tied to a 230kV grid via a 22kV collector. This model is a great asset to understand dynamics, and the unfaulted and faulted behavior of aggregated and single-turbine Type 3 WT systems. The model is then utilized to analyze the response of conventional protection schemes (Line current Differential and Mho Distance elements) and their respective supervisory elements of modern commercial protection relays in real time by hardware-in-the-loop simulation using the RTDS. Differences in the behavior of these elements compared to conventional power systems is noted. Fault are analyzed from the relay's perspective and the reasons for the observed behavior are presented. Challenges associated with sequence components and relay sensitivity are discussed and alternate practices to circumvent these issues are recommended.

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.

RoCoMAR: Robots' Controllable Mobility Aided Routing and Relay Architecture for Mobile Sensor Networks

PubMed Central

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

2013-01-01

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. PMID:23881134

[Testing system design and analysis for the execution units of anti-thrombotic device].

PubMed

Li, Zhelong; Cui, Haipo; Shang, Kun; Liao, Yuehua; Zhou, Xun

2015-02-01

In an anti-thrombotic pressure circulatory device, relays and solenoid valves serve as core execution units. Thus the therapeutic efficacy and patient safety of the device will directly depend on their performance. A new type of testing system for relays and solenoid valves used in the anti-thrombotic device has been developed, which can test action response time and fatigue performance of relay and solenoid valve. PC, data acquisition card and test platform are used in this testing system based on human-computer interaction testing modules. The testing objectives are realized by using the virtual instrument technology, the high-speed data acquisition technology and reasonable software design. The two sets of the system made by relay and solenoid valve are tested. The results proved the universality and reliability of the testing system so that these relays and solenoid valves could be accurately used in the antithrombotic pressure circulatory equipment. The newly-developed testing system has a bright future in the aspects of promotion and application prospect.

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.

Energy Efficiency Optimization in Relay-Assisted MIMO Systems With Perfect and Statistical CSI

NASA Astrophysics Data System (ADS)

Zappone, Alessio; Cao, Pan; Jorswieck, Eduard A.

2014-01-01

A framework for energy-efficient resource allocation in a single-user, amplify-and-forward relay-assisted MIMO system is devised in this paper. Previous results in this area have focused on rate maximization or sum power minimization problems, whereas fewer results are available when bits/Joule energy efficiency (EE) optimization is the goal. The performance metric to optimize is the ratio between the system's achievable rate and the total consumed power. The optimization is carried out with respect to the source and relay precoding matrices, subject to QoS and power constraints. Such a challenging non-convex problem is tackled by means of fractional programming and and alternating maximization algorithms, for various CSI assumptions at the source and relay. In particular the scenarios of perfect CSI and those of statistical CSI for either the source-relay or the relay-destination channel are addressed. Moreover, sufficient conditions for beamforming optimality are derived, which is useful in simplifying the system design. Numerical results are provided to corroborate the validity of the theoretical findings.

The History and Development of the California Relay Service.

ERIC Educational Resources Information Center

Schultz, Stephen

1990-01-01

The California Relay Services (CRS) is a statewide 24-hour dual-party relay system which is designed to bridge the communication gap between the hearing-impaired and the normal-hearing community by using communication assistants to relay calls between those without Telecommunication Devices for the Deaf (TDDs) and TDD-users. (DB)

COMPASS Final Report: Lunar Communications Terminal (LCT)

NASA Technical Reports Server (NTRS)

Oleson, Steven R.; McGuire, Melissa L.

2010-01-01

The Lunar Communications Terminal (LCT) COllaborative Modeling and Parametric Assessment of Space Systems (COMPASS) session designed a terminal to provide communications between lunar South Pole assets, communications relay to/from these assets through an orbiting Lunar Relay Satellite (LRS) and navigation support. The design included a complete master equipment list, power requirement list, configuration design, and brief risk assessment and cost analysis. The Terminal consists of a pallet containing the communications and avionics equipment, surrounded by the thermal control system (radiator), an attached, deployable 10-m tower, upon which were mounted locally broadcasting and receiving modems and a deployable 1 m diameter Ka/S band dish which provides relay communications with the lunar relay satellites and, as a backup, Earth when it is in view. All power was assumed to come from the lunar outpost Habitat. Three LCT design options were explored: a stand-alone LCT servicing the manned outpost, an integrated LCT (into the Habitat or Lunar Lander), and a mini-LCT which provides a reduced level of communication for primarily robotic areas dealing as in situ resource utilization (ISRU) and remote science. Where possible all the designs assumed single fault tolerance. Significant mass savings were found when integrating the LCT into the Habitat or Lander but increases in costs occurred depending upon the level of man rating required for such designs.

47 CFR 78.35 - Assignment or transfer of control.

Code of Federal Regulations, 2013 CFR

2013-10-01

... CABLE TELEVISION RELAY SERVICE Applications and Licenses § 78.35 Assignment or transfer of control. (a) No assignment of the license of a cable television relay station or transfer of control of a CARS... 47 Telecommunication 4 2013-10-01 2013-10-01 false Assignment or transfer of control. 78.35...

47 CFR 78.35 - Assignment or transfer of control.

Code of Federal Regulations, 2014 CFR

2014-10-01

... CABLE TELEVISION RELAY SERVICE Applications and Licenses § 78.35 Assignment or transfer of control. (a) No assignment of the license of a cable television relay station or transfer of control of a CARS... 47 Telecommunication 4 2014-10-01 2014-10-01 false Assignment or transfer of control. 78.35...

47 CFR 78.35 - Assignment or transfer of control.

Code of Federal Regulations, 2010 CFR

2010-10-01

... CABLE TELEVISION RELAY SERVICE Applications and Licenses § 78.35 Assignment or transfer of control. (a) No assignment of the license of a cable television relay station or transfer of control of a CARS... 47 Telecommunication 4 2010-10-01 2010-10-01 false Assignment or transfer of control. 78.35...

47 CFR 78.35 - Assignment or transfer of control.

Code of Federal Regulations, 2011 CFR

2011-10-01

... CABLE TELEVISION RELAY SERVICE Applications and Licenses § 78.35 Assignment or transfer of control. (a) No assignment of the license of a cable television relay station or transfer of control of a CARS... 47 Telecommunication 4 2011-10-01 2011-10-01 false Assignment or transfer of control. 78.35...

47 CFR 78.35 - Assignment or transfer of control.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 4 2012-10-01 2012-10-01 false Assignment or transfer of control. 78.35... CABLE TELEVISION RELAY SERVICE Applications and Licenses § 78.35 Assignment or transfer of control. (a) No assignment of the license of a cable television relay station or transfer of control of a CARS...

VIEW OF HISTORIC SLATE SWITCHBOARD IN THE CONTROL ROOM OF ...

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

VIEW OF HISTORIC SLATE SWITCHBOARD IN THE CONTROL ROOM OF THE ELWHA POWERHOUSE, INCLUDING: METERS, PROTECTIVE RELAYS, AND SWITCHES. NOTE ADDITION OF PERSONAL COMPUTERS FOR POWER METERING AND OPERATIONS. PHOTO BY JET LOWE, HAER, 1995. - Elwha River Hydroelectric System, Elwha Hydroelectric Dam & Plant, Port Angeles, Clallam County, WA

Method for pulse control in a laser including a stimulated brillouin scattering mirror system

DOEpatents

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

2007-10-23

A laser system, such as a master oscillator/power amplifier system, comprises a gain medium and a stimulated Brillouin scattering SBS mirror system. The SBS mirror system includes an in situ filtered SBS medium that comprises a compound having a small negative non-linear index of refraction, such as a perfluoro compound. An SBS relay telescope having a telescope focal point includes a baffle at the telescope focal point which blocks off angle beams. A beam splitter is placed between the SBS mirror system and the SBS relay telescope, directing a fraction of the beam to an alternate beam path for an alignment fiducial. The SBS mirror system has a collimated SBS cell and a focused SBS cell. An adjustable attenuator is placed between the collimated SBS cell and the focused SBS cell, by which pulse width of the reflected beam can be adjusted.

77 FR 20505 - Airworthiness Directives; The Boeing Company Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-05

... Company Model 757 airplanes. This AD requires replacing the power control relays for the fuel boost pumps and override pumps with new relays having a ground fault interrupter (GFI) feature. This AD also requires an electrical bonding resistance measurement for certain GFI relays to verify that certain bonding...

Symbol Error Rate of Underlay Cognitive Relay Systems over Rayleigh Fading Channel

NASA Astrophysics Data System (ADS)

Ho van, Khuong; Bao, Vo Nguyen Quoc

Underlay cognitive systems allow secondary users (SUs) to access the licensed band allocated to primary users (PUs) for better spectrum utilization with the power constraint imposed on SUs such that their operation does not harm the normal communication of PUs. This constraint, which limits the coverage range of SUs, can be offset by relaying techniques that take advantage of shorter range communication for lower path loss. Symbol error rate (SER) analysis of underlay cognitive relay systems over fading channel has not been reported in the literature. This paper fills this gap. The derived SER expressions are validated by simulations and show that underlay cognitive relay systems suffer a high error floor for any modulation level.

25 CFR 542.10 - What are the minimum internal control standards for keno?

Code of Federal Regulations, 2014 CFR

2014-04-01

...) The random number generator shall be linked to the computer system and shall directly relay the... information shall be generated by the computer system. (2) This documentation shall be restricted to... to the computer system shall be adequately restricted (i.e., passwords are changed at least quarterly...

Information management system: A summary discussion. [for use in the space shuttle sortie, modular space station and TDR satellite

NASA Technical Reports Server (NTRS)

Sayers, R. S.

1972-01-01

An information management system is proposed for use in the space shuttle sortie, the modular space station, the tracking data relay satellite and associated ground support systems. Several different information management functions, including data acquisition, transfer, storage, processing, control and display are integrated in the system.

Performance Analysis of Amplify-and-Forward Relaying FSO/SC-QAM Systems over Weak Turbulence Channels and Pointing Error Impairments

NASA Astrophysics Data System (ADS)

Trung, Ha Duyen

2017-12-01

In this paper, the end-to-end performance of free-space optical (FSO) communication system combining with Amplify-and-Forward (AF)-assisted or fixed-gain relaying technology using subcarrier quadrature amplitude modulation (SC-QAM) over weak atmospheric turbulence channels modeled by log-normal distribution with pointing error impairments is studied. More specifically, unlike previous studies on AF relaying FSO communication systems without pointing error effects; the pointing error effect is studied by taking into account the influence of beamwidth, aperture size and jitter variance. In addition, a combination of these models to analyze the combined effect of atmospheric turbulence and pointing error to AF relaying FSO/SC-QAM systems is used. Finally, an analytical expression is derived to evaluate the average symbol error rate (ASER) performance of such systems. The numerical results show that the impact of pointing error on the performance of AF relaying FSO/SC-QAM systems and how we use proper values of aperture size and beamwidth to improve the performance of such systems. Some analytical results are confirmed by Monte-Carlo simulations.

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.

Benefits of a Space-Based Group System Architecture

DTIC Science & Technology

2015-06-01

Relay Satellite TRL Technology Readiness Level TT&C Telemetry, Tracking, and Control UFO UHF Follow-On xv ACKNOWLEDGMENTS I would like to...replacement with more advanced systems. An example of this addition was adding UHF Follow-On ( UFO ) satellite F11, as a gap filler between the UFO

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

TDRSS operations control analysis study

NASA Technical Reports Server (NTRS)

1976-01-01

The use of an operational Tracking and Data Relay Satellite System (TDRSS) and the remaining ground stations for the STDN (GSTDN) was investigated. The operational aspects of TDRSS concepts, GSTDN as a 14-site network, and GSTDN as a 7 site-network were compared and operations control concepts for the configurations developed. Man/machine interface, scheduling system, and hardware/software tradeoff analyses were among the factors considered in the analysis.

Differential correction capability of the GTDS using TDRSS data

NASA Technical Reports Server (NTRS)

Liu, S. Y.; Soskey, D. G.; Jacintho, J.

1980-01-01

A differential correction (DC) capability was implemented in the Goddard Trajectory Determination System (GTDS) to process satellite tracking data acquired via the Tracking and Data Relay Satellite System (TRDRSS). Configuration of the TDRSS is reviewed, observation modeling is presented, and major features of the capability are discussed. The following types of TDRSS data can be processed by GTDS: two way relay range and Doppler measurements, hybrid relay range and Doppler measurements, one way relay Doppler measurements, and differenced one way relay Doppler measurements. These data may be combined with conventional ground based direct tracking data. By using Bayesian weighted least squares techniques, the software allows the simultaneous determination of the trajectories of up to four different satellites - one user satellite and three relay satellites. In addition to satellite trajectories, the following parameters can be optionally solved: for drag coefficient, reflectivity of a satellite for solar radiation pressure, transponder delay, station position, and biases.

Variable current speed controller for eddy current motors

DOEpatents

Gerth, H.L.; Bailey, J.M.; Casstevens, J.M.; Dixon, J.H.; Griffith, B.O.; Igou, R.E.

1982-03-12

A speed control system for eddy current motors is provided in which the current to the motor from a constant frequency power source is varied by comparing the actual motor speed signal with a setpoint speed signal to control the motor speed according to the selected setpoint speed. A three-phase variable voltage autotransformer is provided for controlling the voltage from a three-phase power supply. A corresponding plurality of current control resistors is provided in series with each phase of the autotransformer output connected to inputs of a three-phase motor. Each resistor is connected in parallel with a set of normally closed contacts of plurality of relays which are operated by control logic. A logic circuit compares the selected speed with the actual motor speed obtained from a digital tachometer monitoring the motor spindle speed and operated the relays to add or substract resistance equally in each phase of the motor input to vary the motor current to control the motor at the selected speed.

Spaceborne CO2 laser communications systems

NASA Technical Reports Server (NTRS)

Mcelroy, J. H.; Mcavoy, N.; Johnson, E. H.; Goodwin, F. E.; Peyton, B. J.

1975-01-01

Projections of the growth of earth-sensing systems for the latter half of the 1980's show a data transmission requirement of 300 Mbps and above. Mission constraints and objectives lead to the conclusion that the most efficient technique to return the data from the sensing satellite to a ground station is through a geosynchronous data relay satellite. Of the two links that are involved (sensing satellite to relay satellite and relay satellite to ground), a laser system is most attractive for the space-to-space link. The development of CO2 laser systems for space-to-space applications is discussed with the completion of a 300 Mpbs data relay receiver and its modification into a transceiver. The technology and state-of-the-art of such systems are described in detail.

49 CFR 236.101 - Purpose of inspection and tests; removal from service of relay or device failing to meet test...

Code of Federal Regulations, 2010 CFR

2010-10-01

.../or equipment is maintained in condition to perform its intended function. Electronic device, relay... service of relay or device failing to meet test requirements. 236.101 Section 236.101 Transportation Other... Inspections and Tests; All Systems § 236.101 Purpose of inspection and tests; removal from service of relay or...

Mobile User Connectivity in Relay-Assisted Visible Light Communications.

PubMed

Pešek, Petr; Zvanovec, Stanislav; Chvojka, Petr; Bhatnagar, Manav R; Ghassemlooy, Zabih; Saxena, Prakriti

2018-04-07

In this paper, we investigate relay-assisted visible light communications (VLC) where a mobile user acts as a relay and forwards data from a transmitter to the end mobile user. We analyse the utilization of the amplify-and-forward (AF) and decode-and-forward (DF) relaying schemes. The focus of the paper is on analysis of the behavior of the mobile user acting as a relay while considering a realistic locations of the receivers and transmitters on a standard mobile phone, more specifically with two photodetectors on both sides of a mobile phone and a transmitting LED array located upright. We also investigate dependency of the bit error rate (BER) performance on the azimuth and elevation angles of the mobile relay device within a typical office environment. We provide a new analytical description of BER for AF and DF-based relays in VLC. In addition we compare AF and DF-based systems and show that DF offers a marginal improvement in the coverage area with a BER < 10 -3 and a data rate of 100 Mb/s. Numerical results also illustrate that relay-based systems offer a significant improvement in terms of the coverage compared to direct non-line of sight VLC links.

Mobile User Connectivity in Relay-Assisted Visible Light Communications

PubMed Central

Pešek, Petr; Zvanovec, Stanislav; Chvojka, Petr; Bhatnagar, Manav R.; Ghassemlooy, Zabih; Saxena, Prakriti

2018-01-01

In this paper, we investigate relay-assisted visible light communications (VLC) where a mobile user acts as a relay and forwards data from a transmitter to the end mobile user. We analyse the utilization of the amplify-and-forward (AF) and decode-and-forward (DF) relaying schemes. The focus of the paper is on analysis of the behavior of the mobile user acting as a relay while considering a realistic locations of the receivers and transmitters on a standard mobile phone, more specifically with two photodetectors on both sides of a mobile phone and a transmitting LED array located upright. We also investigate dependency of the bit error rate (BER) performance on the azimuth and elevation angles of the mobile relay device within a typical office environment. We provide a new analytical description of BER for AF and DF-based relays in VLC. In addition we compare AF and DF-based systems and show that DF offers a marginal improvement in the coverage area with a BER < 10–3 and a data rate of 100 Mb/s. Numerical results also illustrate that relay-based systems offer a significant improvement in terms of the coverage compared to direct non-line of sight VLC links. PMID:29642432

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

... automatic interlocking. (a) The control circuits for aspects with indications more favorable than “proceed... 49 Transportation 4 2010-10-01 2010-10-01 false Signal control circuits, selection through track... automatic interlocking. 236.311 Section 236.311 Transportation Other Regulations Relating to Transportation...

Performance Analysis of an Inter-Relay Co-operation in FSO Communication System

NASA Astrophysics Data System (ADS)

Khanna, Himanshu; Aggarwal, Mona; Ahuja, Swaran

2018-04-01

In this work, we analyze the outage and error performance of a one-way inter-relay assisted free space optical link. The assumption of the absence of direct link between the source and destination node is being made for the analysis, and the feasibility of such system configuration is studied. We consider the influence of path loss, atmospheric turbulence and pointing error impairments, and investigate the effect of these parameters on the system performance. The turbulence-induced fading is modeled by independent but not necessarily identically distributed gamma-gamma fading statistics. The closed-form expressions for outage probability and probability of error are derived and illustrated by numerical plots. It is concluded that the absence of line of sight path between source and destination nodes does not lead to significant performance degradation. Moreover, for the system model under consideration, interconnected relaying provides better error performance than the non-interconnected relaying and dual-hop serial relaying techniques.

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.

Relay selection in energy harvesting cooperative networks with rateless codes

NASA Astrophysics Data System (ADS)

Zhu, Kaiyan; Wang, Fei

2018-04-01

This paper investigates the relay selection in energy harvesting cooperative networks, where the relays harvests energy from the radio frequency (RF) signals transmitted by a source, and the optimal relay is selected and uses the harvested energy to assist the information transmission from the source to its destination. Both source and the selected relay transmit information using rateless code, which allows the destination recover original information after collecting codes bits marginally surpass the entropy of original information. In order to improve transmission performance and efficiently utilize the harvested power, the optimal relay is selected. The optimization problem are formulated to maximize the achievable information rates of the system. Simulation results demonstrate that our proposed relay selection scheme outperform other strategies.

Downlink Multihop Transmission Technique for Asymmetric Traffic Accommodation in DS-CDMA/FDD Cellular Communications

NASA Astrophysics Data System (ADS)

Mori, Kazuo; Naito, Katsuhiro; Kobayashi, Hideo

This paper proposes an asymmetric traffic accommodation scheme using a multihop transmission technique for CDMA/FDD cellular communication systems. The proposed scheme exploits the multihop transmission to downlink packet transmissions, which require the large transmission power at their single-hop transmissions, in order to increase the downlink capacity. In these multihop transmissions, vacant uplink band is used for the transmissions from relay stations to destination mobile stations, and this leads more capacity enhancement in the downlink communications. The relay route selection method and power control method for the multihop transmissions are also investigated in the proposed scheme. The proposed scheme is evaluated by computer simulation and the results show that the proposed scheme can achieve better system performance.

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.

Relay Selection for Cooperative Relaying in Wireless Energy Harvesting Networks

NASA Astrophysics Data System (ADS)

Zhu, Kaiyan; Wang, Fei; Li, Songsong; Jiang, Fengjiao; Cao, Lijie

2018-01-01

Energy harvesting from the surroundings is a promising solution to provide energy supply and extend the life of wireless sensor networks. Recently, energy harvesting has been shown as an attractive solution to prolong the operation of cooperative networks. In this paper, we propose a relay selection scheme to optimize the amplify-and-forward (AF) cooperative transmission in wireless energy harvesting cooperative networks. The harvesting energy and channel conditions are considered to select the optimal relay as cooperative relay to minimize the outage probability of the system. Simulation results show that our proposed relay selection scheme achieves better outage performance than other strategies.

Outage Performance Analysis of Relay Selection Schemes in Wireless Energy Harvesting Cooperative Networks over Non-Identical Rayleigh Fading Channels †

PubMed Central

Do, Nhu Tri; Bao, Vo Nguyen Quoc; An, Beongku

2016-01-01

In this paper, we study relay selection in decode-and-forward wireless energy harvesting cooperative networks. In contrast to conventional cooperative networks, the relays harvest energy from the source’s radio-frequency radiation and then use that energy to forward the source information. Considering power splitting receiver architecture used at relays to harvest energy, we are concerned with the performance of two popular relay selection schemes, namely, partial relay selection (PRS) scheme and optimal relay selection (ORS) scheme. In particular, we analyze the system performance in terms of outage probability (OP) over independent and non-identical (i.n.i.d.) Rayleigh fading channels. We derive the closed-form approximations for the system outage probabilities of both schemes and validate the analysis by the Monte-Carlo simulation. The numerical results provide comprehensive performance comparison between the PRS and ORS schemes and reveal the effect of wireless energy harvesting on the outage performances of both schemes. Additionally, we also show the advantages and drawbacks of the wireless energy harvesting cooperative networks and compare to the conventional cooperative networks. PMID:26927119

Outage Performance Analysis of Relay Selection Schemes in Wireless Energy Harvesting Cooperative Networks over Non-Identical Rayleigh Fading Channels.

PubMed

Do, Nhu Tri; Bao, Vo Nguyen Quoc; An, Beongku

2016-02-26

In this paper, we study relay selection in decode-and-forward wireless energy harvesting cooperative networks. In contrast to conventional cooperative networks, the relays harvest energy from the source's radio-frequency radiation and then use that energy to forward the source information. Considering power splitting receiver architecture used at relays to harvest energy, we are concerned with the performance of two popular relay selection schemes, namely, partial relay selection (PRS) scheme and optimal relay selection (ORS) scheme. In particular, we analyze the system performance in terms of outage probability (OP) over independent and non-identical (i.n.i.d.) Rayleigh fading channels. We derive the closed-form approximations for the system outage probabilities of both schemes and validate the analysis by the Monte-Carlo simulation. The numerical results provide comprehensive performance comparison between the PRS and ORS schemes and reveal the effect of wireless energy harvesting on the outage performances of both schemes. Additionally, we also show the advantages and drawbacks of the wireless energy harvesting cooperative networks and compare to the conventional cooperative networks.

Reliability and throughput issues for optical wireless and RF wireless systems

NASA Astrophysics Data System (ADS)

Yu, Meng

The fast development of wireless communication technologies has two main trends. On one hand, in point-to-point communications, the demand for higher throughput called for the emergence of wireless broadband techniques including optical wireless (OW). One the other hand, wireless networks are becoming pervasive. New application of wireless networks ask for more flexible system infrastructures beyond the point-to-point prototype to achieve better performance. This dissertation investigates two topics on the reliability and throughput issues of new wireless technologies. The first topic is to study the capacity, and practical forward error control strategies for OW systems. We investigate the performance of OW systems under weak atmospheric turbulence. We first investigate the capacity and power allocation for multi-laser and multi-detector systems. Our results show that uniform power allocation is a practically optimal solution for paralleled channels. We also investigate the performance of Reed Solomon (RS) codes and turbo codes for OW systems. We present RS codes as good candidates for OW systems. The second topic targets user cooperation in wireless networks. We evaluate the relative merits of amplify-forward (AF) and decode-forward (DF) in practical scenarios. Both analysis and simulations show that the overall system performance is critically affected by the quality of the inter-user channel. Following this result, we investigate two schemes to improve the overall system performance. We first investigate the impact of the relay location on the overall system performance and determine the optimal location of relay. A best-selective single-relay 1 system is proposed and evaluated. Through the analysis of the average capacity and outage, we show that a small candidate pool of 3 to 5 relays suffices to reap most of the "geometric" gain available to a selective system. Second, we propose a new user cooperation scheme to provide an effective better inter-user channel. Most user cooperation protocols work in a time sharing manner, where a node forwards others' messages and sends its own message at different sections within a provisioned time slot. In the proposed scheme the two messages are encoded together in a single codework using network coding and transmitted in the given time slot. We also propose a general multiple-user cooperation framework. Under this framework, we show that network coding can achieve better diversity and provide effective better inter-user channels than time sharing. The last part of the dissertation focuses on multi-relay packet transmission. We propose an adaptive and distributive coding scheme for the relay nodes to adaptively cooperate and forward messages. The adaptive scheme shows performance gain over fixed schemes. Then we shift our viewpoint and represent the network as part of encoders and part of decoders.

78 FR 44475 - Protection System Maintenance Reliability Standard

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-24

... Protection System Maintenance--Phase 2 (Reclosing Relays)). 12. NERC states that the proposed Reliability... of the relay inputs and outputs that are essential to proper functioning of the protection system...] Protection System Maintenance Reliability Standard AGENCY: Federal Energy Regulatory Commission, Energy...

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.

29 CFR 1910.307 - Hazardous (classified) locations.

Code of Federal Regulations, 2011 CFR

2011-07-01

... for the location shall be of a type and design that the employer demonstrates will provide protection... breakers, fuses, motor controllers, receptacles, attachment plugs, meters, relays, instruments, resistors..., local loud speaker and communication systems, ventilation piping, live parts, lightning surge protection...

29 CFR 1910.307 - Hazardous (classified) locations.

Code of Federal Regulations, 2010 CFR

2010-07-01

... for the location shall be of a type and design that the employer demonstrates will provide protection... breakers, fuses, motor controllers, receptacles, attachment plugs, meters, relays, instruments, resistors..., local loud speaker and communication systems, ventilation piping, live parts, lightning surge protection...

The effect of tectonic evolution on lacustrine syn-rift sediment patters in Qikou Sag, Bohaiwan Basin, eastern China

NASA Astrophysics Data System (ADS)

Liao, Y.; Wang, H.; Xu, W.

2013-12-01

Normal fault arrays and associated relay ramps between two overlapping en-echelon normal faults are well known to control the deposition and distribution of sediments in alluvial, fluvial and deltaic systems in rift settings. The influence of transfer zones or relay ramps on sediment routes and dispersal patterns in subaqueous (deeper marine/lacustrine), however, is barely studied and hence less clear. Previous experimental studies indicate that subaqueous relay ramps may act as sediment transportation pathways if certain conditions are available. In this study, we integrate detailed structural and stratigraphic analysis with three-dimensional seismic data and limited well log data from the Qikou Sag to examine the tectonic evolution and the syn-rift sediment patterns response to fault growth and linkage in an active rift setting. Qikou Sag is located at the center of Huanghua Depression, Bohaiwan Basin of eastern China. Structurally, it is a typical continental rift basin characterized by a linked system of two NEE-SWW-striking half-grabens and one E-W-striking graben. Qikou sag is filled with Eocene-Oligocene syn-rift sediments and Miocene to Quaternary post-rift sediments. The Eocene-Oligocene rifting stage can be divided into early rifting period (43-36.5 Ma, the third member and second member of Shahejie Formation, Es3 and Es2), stable rifting period (36.5-29Ma, the first member of Shaehejie Formation, Es1) and fault-depressed diversionary period (29-24.6Ma, the Dongying Formation, Ed). This study focus on the early syn-rift, the third and second member of Shehejie Formation, which is mostly dark-grey mudstone interbedded with fine to coarse-grained sandstone deposited by large-scale turbidity currents in deep-lake. In particular, we use a combination of thickness variability and facies distributions, onlap patterns within a high-resolution sequence stratigraphic framework, integrated with structural geometry, fault activity and subsidence history analysis to investigate the degree of tectonic control on subaqueous sediment transportation and dispersal. Specific attention is paid to deposits close to boundary faults-Gangxi fault, Gangdong fault and Binhai fault and associated relay ramp. Our studies show that significant amount of sediments were deposited on the basin floor close to boundary faults hanging-wall, which were derived from Cangxian uplift and might have originated from channel overspill or flow shedding across the faults. However, minor deposits occurred adjacent to and at the foot of relay ramp, suggesting an influence of these topography features on sediment routing, with the intrabasinal structural high-Beidagang buried hill acting as an additional sediment source. Therefore, the substantial differences between subaerial and subaqueous systems may influence the role of relay ramps in controlling the sediment routes and deposition in Qikou Sag. The attempt to depict subaqueous syn-rift sediment dispersal and relate them with relay ramps is needed to consider the interplay of various factors such as sediment provenience, tectonic activity, ramp geometry, and base level fluctuations in the future investigation.

Telerobot local-remote control architecture for space flight program applications

NASA Technical Reports Server (NTRS)

Zimmerman, Wayne; Backes, Paul; Steele, Robert; Long, Mark; Bon, Bruce; Beahan, John

1993-01-01

The JPL Supervisory Telerobotics (STELER) Laboratory has developed and demonstrated a unique local-remote robot control architecture which enables management of intermittent communication bus latencies and delays such as those expected for ground-remote operation of Space Station robotic systems via the Tracking and Data Relay Satellite System (TDRSS) communication platform. The current work at JPL in this area has focused on enhancing the technologies and transferring the control architecture to hardware and software environments which are more compatible with projected ground and space operational environments. At the local site, the operator updates the remote worksite model using stereo video and a model overlay/fitting algorithm which outputs the location and orientation of the object in free space. That information is relayed to the robot User Macro Interface (UMI) to enable programming of the robot control macros. This capability runs on a single Silicon Graphics Inc. machine. The operator can employ either manual teleoperation, shared control, or supervised autonomous control to manipulate the intended object. The remote site controller, called the Modular Telerobot Task Execution System (MOTES), runs in a multi-processor VME environment and performs the task sequencing, task execution, trajectory generation, closed loop force/torque control, task parameter monitoring, and reflex action. This paper describes the new STELER architecture implementation, and also documents the results of the recent autonomous docking task execution using the local site and MOTES.

Incipient fault detection and power system protection for spaceborne systems

NASA Technical Reports Server (NTRS)

Russell, B. Don; Hackler, Irene M.

1987-01-01

A program was initiated to study the feasibility of using advanced terrestrial power system protection techniques for spacecraft power systems. It was designed to enhance and automate spacecraft power distribution systems in the areas of safety, reliability and maintenance. The proposed power management/distribution system is described as well as security assessment and control, incipient and low current fault detection, and the proposed spaceborne protection system. It is noted that the intelligent remote power controller permits the implementation of digital relaying algorithms with both adaptive and programmable characteristics.

Development of Protection and Control Unit for Distribution Substation

NASA Astrophysics Data System (ADS)

Iguchi, Fumiaki; Hayashi, Hideyuki; Takeuchi, Motohiro; Kido, Mitsuyasu; Kobayashi, Takashi; Yanaoka, Atsushi

The Recently, electronics and IT technologies have been rapidly innovated and have been introduced to power system protection & control system to achieve high reliability, maintainability and more functionality. Concerning the distribution substation application, digital relays have been applied for more than 10 years. Because of a number of electronic devices used for it, product cost becomes higher. Also, products installed during the past high-growth period will be at the end of lifetime and will be replaced. Therefore, replacing market is expected to grow and the reduction of cost is demanded. Considering above mentioned background, second generation digital protection and control unit as a successor is designed to have following concepts. Functional integration based on advanced digital technologies, Ethernet LAN based indoor communication network, cost reduction and downsizing. Pondering above concepts, integration of protection and control function is adopted in contrary to the functional segregation applied to the previous system in order to achieve one-unit concept. Also the adoption of Ethernet LAN for inter-unit communication is objective. This report shows the development of second-generation digital relay for distribution substation, which is equipped with control function and Ethernet LAN by reducing the size of auxiliary transformer unit and the same size as previous product is realized.

Simultaneous energy harvesting and information processing in wireless multiple relays with multiple antennas

NASA Astrophysics Data System (ADS)

Albaaj, Azhar; Makki, S. Vahab A.; Alabkhat, Qassem; Zahedi, Abdulhamid

2017-07-01

Wireless networks suffer from battery discharging specially in cooperative communications when multiple relays have an important role but they are energy constrained. To overcome this problem, energy harvesting from radio frequency signals is applied to charge the node battery. These intermediate nodes have the ability to harvest energy from the source signal and use the energy harvested to transmit information to the destination. In fact, the node tries to harvest energy and then transmit the data to destination. Division of energy harvesting and data transmission can be done in two algorithms: time-switching-based relaying protocol and power-splitting-based relaying protocol. These two algorithms also can be applied in delay-limited and delay-tolerant transmission systems. The previous works have assumed a single relay for energy harvesting, but in this article, the proposed method is concentrated on improving the outage probability and throughput by using multiple antennas in each relay node instead of using single antenna. According to our simulation results, when using multi-antenna relays, ability of energy harvesting is increased and thus system performance will be improved to great extent. Maximum ratio combining scheme has been used when the destination chooses the best signal of relays and antennas satisfying the required signal-to-noise ratio.

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.

Satellite data relay and platform locating in oceanography. Report of the In Situ Ocean Science Working Group

NASA Technical Reports Server (NTRS)

Chase, R.; Cote, C.; Davis, R. E.; Dugan, J.; Frame, D. D.; Halpern, D.; Kerut, E.; Kirk, R.; Mcgoldrick, L.; Mcwilliams, J. C.

1983-01-01

The present and future use of satellites to locate offshore platforms and relay data from in situ sensors to shore was examined. A system of the ARGOS type will satisfy the increasing demand for oceanographic information through data relay and platform location. The improved ship navigation provided by the Global Positioning System (GPS) will allow direct observation of currents from underway ships. Ocean systems are described and demand estimates on satellite systems are determined. The capabilities of the ARGOS system is assessed, including anticipated demand in the next decade.

Performance of an optical relay satellite using Reed-Solomon coding over a cascaded optical PPM and BPSK channel

NASA Technical Reports Server (NTRS)

Divsalar, D.; Naderi, F.

1982-01-01

The nature of the optical/microwave interface aboard the relay satellite is considered. To allow for the maximum system flexibility, without overburdening either the optical or RF channel, demodulating the optical on board the relay satellite but leaving the optical channel decoding to be performed at the ground station is examined. The occurrence of erasures in the optical channel is treated. A hard decision on the erasure (i.e., the relay selecting a symbol at random in case of erasure occurrence) seriously degrades the performance of the overall system. Coding the erasure occurrences at the relay and transmitting this information via an extra bit to the ground station where it can be used by the decoder is suggested. Many examples with varying bit/photon energy efficiency and for the noisy and noiseless optical channel are considered. It is shown that coding the erasure occurrences dramatically improves the performance of the cascaded channel relative to the case of hard decision on the erasure by the relay.

Low power, scalable multichannel high voltage controller

DOEpatents

Stamps, James Frederick [Livermore, CA; Crocker, Robert Ward [Fremont, CA; Yee, Daniel Dadwa [Dublin, CA; Dils, David Wright [Fort Worth, TX

2006-03-14

A low voltage control circuit is provided for individually controlling high voltage power provided over bus lines to a multitude of interconnected loads. An example of a load is a drive for capillary channels in a microfluidic system. Control is distributed from a central high voltage circuit, rather than using a number of large expensive central high voltage circuits to enable reducing circuit size and cost. Voltage is distributed to each individual load and controlled using a number of high voltage controller channel switches connected to high voltage bus lines. The channel switches each include complementary pull up and pull down photo isolator relays with photo isolator switching controlled from the central high voltage circuit to provide a desired bus line voltage. Switching of the photo isolator relays is further controlled in each channel switch using feedback from a resistor divider circuit to maintain the bus voltage swing within desired limits. Current sensing is provided using a switched resistive load in each channel switch, with switching of the resistive loads controlled from the central high voltage circuit.

Low power, scalable multichannel high voltage controller

DOEpatents

Stamps, James Frederick [Livermore, CA; Crocker, Robert Ward [Fremont, CA; Yee, Daniel Dadwa [Dublin, CA; Dils, David Wright [Fort Worth, TX

2008-03-25

A low voltage control circuit is provided for individually controlling high voltage power provided over bus lines to a multitude of interconnected loads. An example of a load is a drive for capillary channels in a microfluidic system. Control is distributed from a central high voltage circuit, rather than using a number of large expensive central high voltage circuits to enable reducing circuit size and cost. Voltage is distributed to each individual load and controlled using a number of high voltage controller channel switches connected to high voltage bus lines. The channel switches each include complementary pull up and pull down photo isolator relays with photo isolator switching controlled from the central high voltage circuit to provide a desired bus line voltage. Switching of the photo isolator relays is further controlled in each channel switch using feedback from a resistor divider circuit to maintain the bus voltage swing within desired limits. Current sensing is provided using a switched resistive load in each channel switch, with switching of the resistive loads controlled from the central high voltage circuit.

Automatic insulation resistance testing apparatus

DOEpatents

Wyant, Francis J.; Nowlen, Steven P.; Luker, Spencer M.

2005-06-14

An apparatus and method for automatic measurement of insulation resistances of a multi-conductor cable. In one embodiment of the invention, the apparatus comprises a power supply source, an input measuring means, an output measuring means, a plurality of input relay controlled contacts, a plurality of output relay controlled contacts, a relay controller and a computer. In another embodiment of the invention the apparatus comprises a power supply source, an input measuring means, an output measuring means, an input switching unit, an output switching unit and a control unit/data logger. Embodiments of the apparatus of the invention may also incorporate cable fire testing means. The apparatus and methods of the present invention use either voltage or current for input and output measured variables.

Real time testing of intelligent relays for synchronous distributed generation islanding detection

NASA Astrophysics Data System (ADS)

Zhuang, Davy

As electric power systems continue to grow to meet ever-increasing energy demand, their security, reliability, and sustainability requirements also become more stringent. The deployment of distributed energy resources (DER), including generation and storage, in conventional passive distribution feeders, gives rise to integration problems involving protection and unintentional islanding. Distributed generators need to be islanded for safety reasons when disconnected or isolated from the main feeder as distributed generator islanding may create hazards to utility and third-party personnel, and possibly damage the distribution system infrastructure, including the distributed generators. This thesis compares several key performance indicators of a newly developed intelligent islanding detection relay, against islanding detection devices currently used by the industry. The intelligent relay employs multivariable analysis and data mining methods to arrive at decision trees that contain both the protection handles and the settings. A test methodology is developed to assess the performance of these intelligent relays on a real time simulation environment using a generic model based on a real-life distribution feeder. The methodology demonstrates the applicability and potential advantages of the intelligent relay, by running a large number of tests, reflecting a multitude of system operating conditions. The testing indicates that the intelligent relay often outperforms frequency, voltage and rate of change of frequency relays currently used for islanding detection, while respecting the islanding detection time constraints imposed by standing distributed generator interconnection guidelines.

75 FR 79317 - Airworthiness Directives; The Boeing Company Model 737-600, -700, -700C, -800, and -900 Series...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-20

... replacement of the power control relays in the P91 and P92 power distribution panels for the fuel boost and override pumps with new, improved relays having a ground fault interrupter (GFI) feature, or installation... specify which relays may be replaced by GFIs or UFIs. We are proposing this AD to prevent pump housing...

Performance analysis of optimal power allocation in wireless cooperative communication systems

NASA Astrophysics Data System (ADS)

Babikir Adam, Edriss E.; Samb, Doudou; Yu, Li

2013-03-01

Cooperative communication has been recently proposed in wireless communication systems for exploring the inherent spatial diversity in relay channels.The Amplify-and-Forward (AF) cooperation protocols with multiple relays have not been sufficiently investigated even if it has a low complexity in term of implementation. We consider in this work a cooperative diversity system in which a source transmits some information to a destination with the help of multiple relay nodes with AF protocols and investigate the optimality of allocating powers both at the source and the relays system by optimizing the symbol error rate (SER) performance in an efficient way. Firstly we derive a closedform SER formulation for MPSK signal using the concept of moment generating function and some statistical approximations in high signal to noise ratio (SNR) for the system under studied. We then find a tight corresponding lower bound which converges to the same limit as the theoretical upper bound and develop an optimal power allocation (OPA) technique with mean channel gains to minimize the SER. Simulation results show that our scheme outperforms the equal power allocation (EPA) scheme and is tight to the theoretical approximation based on the SER upper bound in high SNR for different number of relays.

47 CFR 90.243 - Mobile relay stations.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Service. (b) Special provisions for mobile relay operations: (1) In the Public Safety Pool, systems... authorized to operate on any frequency available for assignment to base stations. (5) A mobile station associated with mobile relay station(s) may not be authorized to operate on a frequency below 25 MHz. (c...

Rate Control for Network-Coded Multipath Relaying with Time-Varying Connectivity

DTIC Science & Technology

2010-12-10

Armen Babikyan, Nathaniel M. Jones, Thomas H. Shake, and Andrew P. Worthen MIT Lincoln Laboratory 244 Wood Street Lexington, MA 02420 DDRE, 1777...delay U U U U SAR 11 Zach Sweet 781-981-5997 1 Rate Control for Network-Coded Multipath Relaying with Time-Varying Connectivity Brooke Shrader, Armen

76 FR 61476 - Petition for Waiver of Compliance

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-04

... locking; and 236.109, Time releases, timing relays and timing devices; on vital microprocessor-based... microprocessor-based locking systems. These tests, at this interval, would replace the tests currently required... listed in Exhibit B. 2. All future purchases of microprocessor-controlled interlocking locations. 3...

Wide-area measurement system-based supervision of protection schemes with minimum number of phasor measurement units.

PubMed

Gajare, Swaroop; Rao, J Ganeswara; Naidu, O D; Pradhan, Ashok Kumar

2017-08-13

Cascade tripping of power lines triggered by maloperation of zone-3 relays during stressed system conditions, such as load encroachment, power swing and voltage instability, has led to many catastrophic power failures worldwide, including Indian blackouts in 2012. With the introduction of wide-area measurement systems (WAMS) into the grids, real-time monitoring of transmission network condition is possible. A phasor measurement unit (PMU) sends time-synchronized data to a phasor data concentrator, which can provide a control signal to substation devices. The latency associated with the communication system makes WAMS suitable for a slower form of protection. In this work, a method to identify the faulted line using synchronized data from strategic PMU locations is proposed. Subsequently, a supervisory signal is generated for specific relays in the system for any disturbance or stressed condition. For a given system, an approach to decide the strategic locations for PMU placement is developed, which can be used for determining the minimum number of PMUs required for application of the method. The accuracy of the scheme is tested for faults during normal and stressed conditions in a New England 39-bus system simulated using EMTDC/PSCAD software. With such a strategy, maloperation of relays can be averted in many situations and thereby blackouts/large-scale disturbances can be prevented.This article is part of the themed issue 'Energy management: flexibility, risk and optimization'. © 2017 The Author(s).

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.

Effects of Distributed Generation on Overcurrent Relay Coordination and an Adaptive Protection Scheme

NASA Astrophysics Data System (ADS)

Ilik, Semih C.; Arsoy, Aysen B.

2017-07-01

Integration of distributed generation (DG) such as renewable energy sources to electrical network becomes more prevalent in recent years. Grid connection of DG has effects on load flow directions, voltage profile, short circuit power and especially protection selectivity. Applying traditional overcurrent protection scheme is inconvenient when system reliability and sustainability are considered. If a fault happens in DG connected network, short circuit contribution of DG, creates additional branch element feeding the fault current; compels to consider directional overcurrent (OC) protection scheme. Protection coordination might get lost for changing working conditions when DG sources are connected. Directional overcurrent relay parameters are determined for downstream and upstream relays when different combinations of DG connected singular or plural, on radial test system. With the help of proposed flow chart, relay parameters are updated and coordination between relays kept sustained for different working conditions in DigSILENT PowerFactory program.

Development of an adaptive optics test-bed for relay mirror applications

NASA Astrophysics Data System (ADS)

Mansell, Justin D.; Jacobs, Arturo A.; Maynard, Morris

2005-08-01

The relay mirror concept involves deploying a passive optical station at a high altitude for relaying a beam from a laser weapon to a target. Relay mirrors have been proposed as a method of increasing the range of laser weapons that is less costly than deploying a larger number of laser weapons. Relay mirrors will only be effective if the beam spreading and beam quality degradation induced by atmospheric aberrations and thermal blooming can be mitigated. In this paper we present the first phase of a multi-year effort to develop a theoretical and experimental capability at Boeing-SVS to study these problems. A team from MZA and Boeing-SVS has developed a laboratory test-bed consisting of a distributed atmospheric path simulated by three liquid crystal phase screens, a Shack-Hartmann wavefront sensor, and a MEMS membrane deformable mirror. We present results of AO component calibration and evaluation, the system construction, and the system performance.

Design Concepts for a Small Space-Based GEO Relay Satellite for Missions Between Low Earth and near Earth Orbits

NASA Technical Reports Server (NTRS)

Bhasin, Kul B.; Warner, Joseph D.; Oleson, Steven; Schier, James

2014-01-01

The main purpose of the Small Space-Based Geosynchronous Earth orbiting (GEO) satellite is to provide a space link to the user mission spacecraft for relaying data through ground networks to user Mission Control Centers. The Small Space Based Satellite (SSBS) will provide services comparable to those of a NASA Tracking Data Relay Satellite (TDRS) for the same type of links. The SSBS services will keep the user burden the same or lower than for TDRS and will support the same or higher data rates than those currently supported by TDRS. At present, TDRSS provides links and coverage below GEO; however, SSBS links and coverage capability to above GEO missions are being considered for the future, especially for Human Space Flight Missions (HSF). There is also a rising need for the capability to support high data rate links (exceeding 1 Gbps) for imaging applications. The communication payload on the SSBS will provide S/Ka-band single access links to the mission and a Ku-band link to the ground, with an optical communication payload as an option. To design the communication payload, various link budgets were analyzed and many possible operational scenarios examined. To reduce user burden, using a larger-sized antenna than is currently in use by TDRS was considered. Because of the SSBS design size, it was found that a SpaceX Falcon 9 rocket could deliver three SSBSs to GEO. This will greatly reduce the launch costs per satellite. Using electric propulsion was also evaluated versus using chemical propulsion; the power system size and time to orbit for various power systems were also considered. This paper will describe how the SSBS will meet future service requirements, concept of operations, and the design to meet NASA users' needs for below and above GEO missions. These users' needs not only address the observational mission requirements but also possible HSF missions to the year 2030. We will provide the trade-off analysis of the communication payload design in terms of the number of links looking above and below GEO; the detailed design of a GEO SSBS spacecraft bus and its accommodation of the communication payload, and a summary of the trade study that resulted in the selection of the Falcon 9 launch vehicle to deploy the SSBS and its impact on cost reductions per satellite. ======================================================================== Several initiatives have taken place within NASA1 and international space agencies2 to create a human exploration strategy for expanding human presence into the solar system; these initiatives have been driven by multiple factors to benefit Earth. Of the many elements in the strategy one stands out: to send robotic and human missions to destinations beyond Low Earth Orbit (LEO), including cis-lunar space, Near-Earth Asteroids (NEAs), the Moon, and Mars and its moons.3, 4 The time frame for human exploration to various destinations, based on the public information available,1,4 is shown in Figure 1. Advance planning is needed to define how future space communications services will be provided in the new budget environment to meet future space communications needs. The spacecraft for these missions can be dispersed anywhere from below LEO to beyond GEO, and to various destinations within the solar system. NASA's Space Communications and Navigation (SCaN) program office provides communication and tracking services to space missions during launch, in-orbit testing, and operation phases. Currently, SCaN's space networking relay satellites mainly provide services to users below GEO, at Near Earth Orbit (NEO), below LEO, and in deep space. The potential exists for using a space-based relay satellite, located in the vicinity of various solar system destinations, to provide communication space links to missions both below and above its orbit. Such relays can meet the needs of human exploration missions for maximum connectivity to Earth locations and for reduced latency. In the past, several studies assessed the ability of satellite-based relays working above GEO in conjunction with Earth ground stations. Many of these focused on the trade between space relay and direct-to-Earth station links5,6,7. Several others focused on top-level architecture based on relays at various destinations8,9,10,11,12. Much has changed in terms of microwave and optical technology since the publication of the referenced papers; Ka-band communication systems are being deployed, optical communication is being demonstrated, and spacecraft buses are becoming increasingly more functional and operational. A design concept study was undertaken to access the potential for deploying a Small Space-Based Satellite (SSBS) relay capable of serving missions between LEO and NEO. The needs of future human exploration missions were analyzed, and a notional relay-based architecture concept was generated as shown in Fig. 1. Relay satellites in Earth through cis-Lunar orbits are normally located in stable orbits requiring low fuel consumption. Relay satellites for Mars orbit are normally selected based on the mission requirement and projected fuel consumption. Relay satellites have extreme commonalities of functions between them, differing only in the redundancy and frequencies used; therefore, the relay satellite in GEO was selected for further analysis since it will be the first step in achieving a relay-based architecture for human exploration missions (see Fig.Figure 2). The mission design methodology developed by the Collaborative Modeling for Parametric Assessment of Space Systems (COMPASS) team13 was used to produce the satellite relay design and to perform various design trades. At the start of the activity, the team was provided with the detailed concept of the notional architecture and the system and communication payload drivers.

Cultivar and planting date selection for relay-cropping soybean with winter oilseeds

USDA-ARS?s Scientific Manuscript database

Double- and relay-cropping soybean with winter camelina (Camelina sativa L. Crantz) and pennycress (Thlaspi arvense L.) have been shown to be viable cropping systems for the Upper Midwest. Relaying soybean with these winter oilseeds can result in greater total seed yield (i.e., both combined) and ec...

Flight Integral Field Spectrograph (IFS) Optical Design for WFIRST Coronagraphic Exoplanet Demonstration

NASA Technical Reports Server (NTRS)

Gong, Qian; Groff, Tyler D.; Zimmerman, Neil; Mandell, Avi; McElwain, Michael; Rizzo, Maxime; Saxena, Prabal

2017-01-01

Based on the experience from Prototype Imaging Spectrograph for Coronagraphic Exoplanet Studies (PISCES) for WFIRST, we have moved to the flight instrument design phase. The specifications for flight IFS have similarities and differences from the prototype. This paper starts with the science and system requirement, discusses a number of critical trade-offs: such as IFS type selection, lenslet array shape and layout versus detector pixel accuracy, how to accommodate the larger Field Of View (FOV) and wider wavelength band for a potential add-on StarShade occulter. Finally, the traditional geometric optical design is also investigated and traded: reflective versus refractive, telecentric versus non-telecentric relay. The relay before the lenslet array controls the chief angle distribution on the lenslet array. Our previous paper has addressed how the relay design combined with lenslet arraypinhole mask can further compress the residual star light and increase the contrast. Finally, a complete phase A IFS optical design is presented.

THERMOCOUPLE VACUUM GAUGE

DOEpatents

Price, G.W.

1954-08-01

A protector device is described for use in controlling the pressure within a cyclotron. In particular, an electrical circuit functions to actuate a vacuum pump when a predetermined low pressure is reached and disconnect the pump when the pressure increases abcve a certain value. The principal feature of the control circuit lies in the use of a voltage divider network at the input to a relay control tube comprising two parallel, adjustable resistances wherein one resistor is switched into the circuit when the relay connects the pump to a power source. With this arrangement the relay is energized at one input level received from a sensing element within the cyclotron chamber and is de-energized when a second input level, representing the higher pressure limit, is reached.

Attitude control challenges for earth orbiters of the 1980's

NASA Technical Reports Server (NTRS)

Hibbard, W.

1980-01-01

Experience gained in designing attitude control systems for orbiting spacecraft of the late 1980's is related. Implications for satellite attitude control design of the guidance capabilities, rendezvous and recovery requirements, use of multiple-use spacecraft and the development of large spacecraft associated with the advent of the Space Shuttle are considered. Attention is then given to satellite attitude control requirements posed by the Tracking and Data Relay Satellite System, the Global Positioning System, the NASA End-to-End Data System, and Shuttle-associated subsatellites. The anticipated completion and launch of the Space Telescope, which will provide one of the first experiences with the new generation of attitude control, is also pointed out.

Finite-SNR analysis for partial relaying cooperation with channel coding and opportunistic relay selection

NASA Astrophysics Data System (ADS)

Vu, Thang X.; Duhamel, Pierre; Chatzinotas, Symeon; Ottersten, Bjorn

2017-12-01

This work studies the performance of a cooperative network which consists of two channel-coded sources, multiple relays, and one destination. To achieve high spectral efficiency, we assume that a single time slot is dedicated to relaying. Conventional network-coded-based cooperation (NCC) selects the best relay which uses network coding to serve the two sources simultaneously. The bit error rate (BER) performance of NCC with channel coding, however, is still unknown. In this paper, we firstly study the BER of NCC via a closed-form expression and analytically show that NCC only achieves diversity of order two regardless of the number of available relays and the channel code. Secondly, we propose a novel partial relaying-based cooperation (PARC) scheme to improve the system diversity in the finite signal-to-noise ratio (SNR) regime. In particular, closed-form expressions for the system BER and diversity order of PARC are derived as a function of the operating SNR value and the minimum distance of the channel code. We analytically show that the proposed PARC achieves full (instantaneous) diversity order in the finite SNR regime, given that an appropriate channel code is used. Finally, numerical results verify our analysis and demonstrate a large SNR gain of PARC over NCC in the SNR region of interest.

Mutual-Information-Based Incremental Relaying Communications for Wireless Biomedical Implant Systems

PubMed Central

Liao, Yangzhe; Cai, Qing; Ai, Qingsong; Liu, Quan

2018-01-01

Network lifetime maximization of wireless biomedical implant systems is one of the major research challenges of wireless body area networks (WBANs). In this paper, a mutual information (MI)-based incremental relaying communication protocol is presented where several on-body relay nodes and one coordinator are attached to the clothes of a patient. Firstly, a comprehensive analysis of a system model is investigated in terms of channel path loss, energy consumption, and the outage probability from the network perspective. Secondly, only when the MI value becomes smaller than the predetermined threshold is data transmission allowed. The communication path selection can be either from the implanted sensor to the on-body relay then forwards to the coordinator or from the implanted sensor to the coordinator directly, depending on the communication distance. Moreover, mathematical models of quality of service (QoS) metrics are derived along with the related subjective functions. The results show that the MI-based incremental relaying technique achieves better performance in comparison to our previous proposed protocol techniques regarding several selected performance metrics. The outcome of this paper can be applied to intra-body continuous physiological signal monitoring, artificial biofeedback-oriented WBANs, and telemedicine system design. PMID:29419784

Mutual-Information-Based Incremental Relaying Communications for Wireless Biomedical Implant Systems.

PubMed

Liao, Yangzhe; Leeson, Mark S; Cai, Qing; Ai, Qingsong; Liu, Quan

2018-02-08

Network lifetime maximization of wireless biomedical implant systems is one of the major research challenges of wireless body area networks (WBANs). In this paper, a mutual information (MI)-based incremental relaying communication protocol is presented where several on-body relay nodes and one coordinator are attached to the clothes of a patient. Firstly, a comprehensive analysis of a system model is investigated in terms of channel path loss, energy consumption, and the outage probability from the network perspective. Secondly, only when the MI value becomes smaller than the predetermined threshold is data transmission allowed. The communication path selection can be either from the implanted sensor to the on-body relay then forwards to the coordinator or from the implanted sensor to the coordinator directly, depending on the communication distance. Moreover, mathematical models of quality of service (QoS) metrics are derived along with the related subjective functions. The results show that the MI-based incremental relaying technique achieves better performance in comparison to our previous proposed protocol techniques regarding several selected performance metrics. The outcome of this paper can be applied to intra-body continuous physiological signal monitoring, artificial biofeedback-oriented WBANs, and telemedicine system design.

Hardwired Control Changes For NSTX DC Power Feeds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ramakrishnan, S.

The National Spherical Torus Experiment (NSTX) has been designed and installed in the existing facilities at Princeton Plasma Physics Laboratory (PPPL). Most of the hardware, plant facilities, auxiliary sub-systems, and power systems originally used for the Tokamak Fusion Test Reactor (TFTR) have been used with suitable modifications to reflect NSTX needs. The original TFTR Hardwired Control System (HCS) with electromechanical relays was used for NSTX DC Power loop control and protection during NSTX operations. As part of the NSTX Upgrade, the HCS is being changed to a PLC-based system with the same control logic. This paper gives a description ofmore » the changeover to the new PLC-based system __________________________________________________« less

Performance Analysis of Physical Layer Security of Opportunistic Scheduling in Multiuser Multirelay Cooperative Networks

PubMed Central

Shim, Kyusung; Do, Nhu Tri; An, Beongku

2017-01-01

In this paper, we study the physical layer security (PLS) of opportunistic scheduling for uplink scenarios of multiuser multirelay cooperative networks. To this end, we propose a low-complexity, yet comparable secrecy performance source relay selection scheme, called the proposed source relay selection (PSRS) scheme. Specifically, the PSRS scheme first selects the least vulnerable source and then selects the relay that maximizes the system secrecy capacity for the given selected source. Additionally, the maximal ratio combining (MRC) technique and the selection combining (SC) technique are considered at the eavesdropper, respectively. Investigating the system performance in terms of secrecy outage probability (SOP), closed-form expressions of the SOP are derived. The developed analysis is corroborated through Monte Carlo simulation. Numerical results show that the PSRS scheme significantly improves the secure ability of the system compared to that of the random source relay selection scheme, but does not outperform the optimal joint source relay selection (OJSRS) scheme. However, the PSRS scheme drastically reduces the required amount of channel state information (CSI) estimations compared to that required by the OJSRS scheme, specially in dense cooperative networks. PMID:28212286

76 FR 60710 - Airworthiness Directives; The Boeing Company Model 737-600, -700, -700C, -800, and -900 Series...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-30

... Bulletin 737-28A1201, Revision 1, dated May 28, 2009. Subject (d) Joint Aircraft System Component (JASC... control relays in the P91 and P92 power distribution panels for the fuel boost and override pumps with new... INFORMATION CONTACT: Georgios Roussos, Aerospace Engineer, Systems and Equipment Branch, ANM-130S, FAA...

78 FR 71710 - Notice of Application for Approval of Discontinuance or Modification of a Railroad Signal System

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-29

... installation of cab signals without wayside signaling between Control Point (CP) Kiski, Milepost (MP) LC 47.8, and CP Penn, MP LC 77.9, on the Conemaugh Line, Pittsburgh Division. CP Kiski, CP Harris, CP Beale, CP Sharp, and CP Etna will be upgraded from existing, legacy, relay-based signal systems to electronic...

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.

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.

GSFC network operations with Tracking and Data Relay Satellites

NASA Technical Reports Server (NTRS)

Spearing, R.; Perreten, D. E.

1984-01-01

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.

Staged-Fault Testing of Distance Protection Relay Settings

NASA Astrophysics Data System (ADS)

Havelka, J.; Malarić, R.; Frlan, K.

2012-01-01

In order to analyze the operation of the protection system during induced fault testing in the Croatian power system, a simulation using the CAPE software has been performed. The CAPE software (Computer-Aided Protection Engineering) is expert software intended primarily for relay protection engineers, which calculates current and voltage values during faults in the power system, so that relay protection devices can be properly set up. Once the accuracy of the simulation model had been confirmed, a series of simulations were performed in order to obtain the optimal fault location to test the protection system. The simulation results were used to specify the test sequence definitions for the end-to-end relay testing using advanced testing equipment with GPS synchronization for secondary injection in protection schemes based on communication. The objective of the end-to-end testing was to perform field validation of the protection settings, including verification of the circuit breaker operation, telecommunication channel time and the effectiveness of the relay algorithms. Once the end-to-end secondary injection testing had been completed, the induced fault testing was performed with three-end lines loaded and in service. This paper describes and analyses the test procedure, consisting of CAPE simulations, end-to-end test with advanced secondary equipment and staged-fault test of a three-end power line in the Croatian transmission system.

Identification of FOPDT and SOPDT process dynamics using closed loop test.

PubMed

Bajarangbali, Raghunath; Majhi, Somanath; Pandey, Saurabh

2014-07-01

In this paper, identification of stable and unstable first order, second order overdamped and underdamped process dynamics with time delay is presented. Relay with hysteresis is used to induce a limit cycle output and using this information, unknown process model parameters are estimated. State space based generalized analytical expressions are derived to achieve accurate results. To show the performance of the proposed method expressions are also derived for systems with a zero. In real time systems, measurement noise is an important issue during identification of process dynamics. A relay with hysteresis reduces the effect of measurement noise, in addition a new multiloop control strategy is proposed to recover the original limit cycle. Simulation results are included to validate the effectiveness of the proposed method. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

Wireless Energy Harvesting Two-Way Relay Networks with Hardware Impairments.

PubMed

Peng, Chunling; Li, Fangwei; Liu, Huaping

2017-11-13

This paper considers a wireless energy harvesting two-way relay (TWR) network where the relay has energy-harvesting abilities and the effects of practical hardware impairments are taken into consideration. In particular, power splitting (PS) receiver is adopted at relay to harvests the power it needs for relaying the information between the source nodes from the signals transmitted by the source nodes, and hardware impairments is assumed suffered by each node. We analyze the effect of hardware impairments [-20]on both decode-and-forward (DF) relaying and amplify-and-forward (AF) relaying networks. By utilizing the obtained new expressions of signal-to-noise-plus-distortion ratios, the exact analytical expressions of the achievable sum rate and ergodic capacities for both DF and AF relaying protocols are derived. Additionally, the optimal power splitting (OPS) ratio that maximizes the instantaneous achievable sum rate is formulated and solved for both protocols. The performances of DF and AF protocols are evaluated via numerical results, which also show the effects of various network parameters on the system performance and on the OPS ratio design.

47 CFR 74.432 - Licensing requirements and procedures.

Code of Federal Regulations, 2013 CFR

2013-10-01

... EXPERIMENTAL RADIO, AUXILIARY, SPECIAL BROADCAST AND OTHER PROGRAM DISTRIBUTIONAL SERVICES Remote Pickup... transmitter or points of any intercity relay system on frequencies in Groups I and J. (d) Base stations may be... at the control point of the station. (k) In case of permanent discontinuance of operations of a...

Potential Means of Cost Reduction in Grade Crossing Motorist-Warning Control Equipment : Volume 1. Overview, Technology Survey and Relay Alternatives

DOT National Transportation Integrated Search

1977-12-01

The results of a recent study of railroad-highway grade crossing warning system technology are presented. Emphasis in the investigation was placed on the determination of the potential for significant reduction in equipment, installation and maintena...

Overview of the NSTX Control System

DOE Office of Scientific and Technical Information (OSTI.GOV)

P. Sichta; J. Dong; G. Oliaro

2001-12-03

The National Spherical Torus Experiment (NSTX) is an innovative magnetic fusion device that was constructed by the Princeton Plasma Physics Laboratory (PPPL) in collaboration with the Oak Ridge National Laboratory, Columbia University, and the University of Washington at Seattle. Since achieving first plasma in 1999, the device has been used for fusion research through an international collaboration of more than twenty institutions. The NSTX is operated through a collection of control systems that encompass a wide range of technology, from hardwired relay controls to real-time control systems with giga-FLOPS of capability. This paper presents a broad introduction to the controlmore » systems used on NSTX, with an emphasis on the computing controls, data acquisition, and synchronization systems.« less

Feedforward inhibitory control of sensory information in higher-order thalamic nuclei.

PubMed

Lavallée, Philippe; Urbain, Nadia; Dufresne, Caroline; Bokor, Hajnalka; Acsády, László; Deschênes, Martin

2005-08-17

Sensory stimuli evoke strong responses in thalamic relay cells, which ensure a faithful relay of information to the neocortex. However, relay cells of the posterior thalamic nuclear group in rodents, despite receiving significant trigeminal input, respond poorly to vibrissa deflection. Here we show that sensory transmission in this nucleus is impeded by fast feedforward inhibition mediated by GABAergic neurons of the zona incerta. Intracellular recordings of posterior group neurons revealed that the first synaptic event after whisker deflection is a prominent inhibition. Whisker-evoked EPSPs with fast rise time and longer onset latency are unveiled only after lesioning the zona incerta. Excitation survives barrel cortex lesion, demonstrating its peripheral origin. Electron microscopic data confirm that trigeminal axons make large synaptic terminals on the proximal dendrites of posterior group cells and on the somata of incertal neurons. Thus, the connectivity of the system allows an unusual situation in which inhibition precedes ascending excitation resulting in efficient shunting of the responses. The dominance of inhibition over excitation strongly suggests that the paralemniscal pathway is not designed to relay inputs triggered by passive whisker deflection. Instead, we propose that this pathway operates through disinhibition, and that the posterior group forwards to the cerebral cortex sensory information that is contingent on motor instructions.

Generalized synchronization in relay systems with instantaneous coupling

NASA Astrophysics Data System (ADS)

Gutiérrez, R.; Sevilla-Escoboza, R.; Piedrahita, P.; Finke, C.; Feudel, U.; Buldú, J. M.; Huerta-Cuellar, G.; Jaimes-Reátegui, R.; Moreno, Y.; Boccaletti, S.

2013-11-01

We demonstrate the existence of generalized synchronization in systems that act as mediators between two dynamical units that, in turn, show complete synchronization with each other. These are the so-called relay systems. Specifically, we analyze the Lyapunov spectrum of the full system to elucidate when complete and generalized synchronization appear. We show that once a critical coupling strength is achieved, complete synchronization emerges between the systems to be synchronized, and at the same point, generalized synchronization with the relay system also arises. Next, we use two nonlinear measures based on the distance between phase-space neighbors to quantify the generalized synchronization in discretized time series. Finally, we experimentally show the robustness of the phenomenon and of the theoretical tools here proposed to characterize it.

Common Submarine Radio Room: A Case Study of a System of Systems Approach

DTIC Science & Technology

2014-09-01

38 a. Military Strategic and Tactical Relay System / Navy Extremely High Frequency Program / Navy Multiband Terminal...sigma MCAP medium data rate channel access protocol MILSATCOM military satellite communications MILSTAR military strategic and tactical relay system...challenges between the various communications systems throughout the U.S. military place additional burdens and vulnerabilities on the warfighter. While

Target isolation system, high power laser and laser peening method and system using same

DOEpatents

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

2007-11-06

A system for applying a laser beam to work pieces, includes a laser system producing a high power output beam. Target delivery optics are arranged to deliver the output beam to a target work piece. A relay telescope having a telescope focal point is placed in the beam path between the laser system and the target delivery optics. The relay telescope relays an image between an image location near the output of the laser system and an image location near the target delivery optics. A baffle is placed at the telescope focal point between the target delivery optics and the laser system to block reflections from the target in the target delivery optics from returning to the laser system and causing damage.

Section 7 reactor incident file general information from 1945

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1969-01-10

At 0308 on January 10, 1966, both B and C Reactors ``scrammed`` due to an electrical fault on Line C2-L8 caused by a raccoon coming in contact with the 13-8 KV line on top of transformer No. 2 at 182-B Building. Line C2-L8 relayed out at the 151-B Building. Details of the occurrence at 151-B are covered in the attachment. C-Reactor scrammed due to reduced voltage on the pressure monitor system. The reduction in voltage caused the auxiliary relays of the pressure monitor ground detector to open, de-energizing the end result relays PSR and PSRA. The safety circuit trip identificationmore » system displayed ``Pressure Monitor`` and ``Ground Detector.`` B-Reactor scrammed by a power failure signal from 190-B Building. The power failure relays for pump numbers 1 and 3 opened due to these pumps contributing power to the fault. The power failure relays at 190-B remained open long enough for the end result relays PF and PFA to open. Since these relays are timed delayed, 0.26 seconds, the power failure relays must have remained open at least that long. At the 190-B Building the steam turbines started due to the power failure relays for pump numbers 1 and 3 opening. The main process pumps remained stable and continued to supply normal flow to the reactor. Pumps were tripped from the line at 182-B and 183-B Buildings. The surge suppressors cycled normally and the turbine export pumps started as a result of low export line pressure. No power equipment was affected in C Area.« less

The SILEX experiment system operations

NASA Technical Reports Server (NTRS)

Demelenne, B.

1994-01-01

The European Space Agency is going to conduct an inter orbit link experiment which will connect a low Earth orbiting satellite and a Geostationary satellite via optical terminals. This experiment has been called SILEX (Semiconductor Inter satellite Link EXperiment). Two payloads will be built. One called PASTEL (PASsager de TELecommunication) will be embarked on the French Earth observation satellite SPOT4. The future European experimental data relay satellite ARTEMIS (Advanced Relay and TEchnology MISsion) will carry the OPALE terminal (Optical PAyload Experiment). The principal characteristic of the mission is a 50 Megabits flow of data transmitted via the optical satellite link. The relay satellite will route the data via its feeder link thus permitting a real time reception in the European region of images taken by the observation satellite. The PASTEL terminal has been designed to cover up to 9 communication sessions per day with an average of 5. The number of daily contact opportunities with the low earth orbiting satellite will be increased and the duration will be much longer than the traditional passes over a ground station. The terminals have an autonomy of 24 hours with respect to ground control. Each terminal will contain its own orbit model and that of its counter terminal for orbit prediction and for precise computation of pointing direction. Due to the very narrow field of view of the communication laser beam, the orbit propagation calculation needs to be done with a very high accuracy. The European Space Agency is responsible for the operation of both terminals. A PASTEL Mission Control System (PMCS) is being developed to control the PASTEL terminal on board SPOT4. The PMCS will interface with the SPOT4 Control Centre for the execution of the PASTEL operations. The PMCS will also interface with the ARTEMIS Mission Control System for the planning and the coordination of the operation. It is the first time that laser technology will be used to support inter-satellite links in Europe. Due to the complexity and experimental character of this new optical technology, the SILEX experiment control facilities will be designed to allow as much operational flexibility as possible.

Development of a Real-Time Hardware-in-the-Loop Power Systems Simulation Platform to Evaluate Commercial Microgrid Controllers

DTIC Science & Technology

2016-02-19

power converter, a solar photovoltaic ( PV ) system with inverter, and eighteen breakers. (Future work will require either validation of these models...custom control software. (For this project, this was done for the energy storage, solar PV , and breakers.) Implement several relay protection functions...for the PV array is given in Section A.3. This profile was generated by applying a decimation/interpolation filter to the signal from a solar flux

TR-1203: Development of a Real-Time Hardware-in-the-Loop Power Systems Simulation Platform to Evaluate Commercial Microgrid Controllers

DTIC Science & Technology

2016-02-23

power converter, a solar photovoltaic ( PV ) system with inverter, and eighteen breakers. (Future work will require either validation of these models or...control software. (For this project, this was done for the energy storage, solar PV , and breakers.) Implement several relay protection functions to...the PV array is given in Section A.3. This profile was generated by applying a decimation/interpolation filter to the signal from a solar flux point

The Development of an Information System Master Plan for the Pacific Missile Range Facility, Barking Sands, Hawaii

DTIC Science & Technology

1992-03-01

sites and support facilities are located on the islands of Niihau and Oahu. Figure 1 depicts the overall layout of PMRF. [Ref. 4: p. 2] In addition...the HIANG facility at Kokee: • a wideband microwave system serving Niihau Island remotely controls operation of the AN/APS-134 surveillance radar, and...provides relay of digitized radar data, control data and voice between the remotely operated, unmanned radar on Niihau Island and Barking Sands

Lack of relay toxicity in ferret hybrids fed carbaryl-treated prairie dogs.

PubMed

Orsted, K M; Dubay, S A; Raisbeck, M F; Siemion, R S; Sanchez, D A; Williams, E S

1998-04-01

Carbaryl (1-napthol methylcarbamate) is being considered for control of fleas on prairie dogs (Cynomys spp.) used in black-footed ferret (Mustela nigripes) recovery in the western United States. The potential for relay toxicity in ferrets was determined by feeding carbaryl treated prairie dogs to black-footed ferret x Siberian polecat (M. eversmanni) hybrids. Adult prairie dogs were treated topically with 2.5 g of commercial 5% carbaryl dust sold as flea powder. After 14 days prairie dogs were killed and fed to ferrets. Potential for relay toxicity was evaluated by analyzing ferret blood cholinesterase (CHe), prairie dog brain Che, and hepatic carbamate concentration. There was no difference between pre- and post-exposure blood CHe activity, nor did treated prairie dog brain CHe differ significantly from controls. Post-exposure blood CHe did not exhibit reactivation after dilution in aqueous buffer. Hepatic carbaryl concentrations were less than detection limits (50 ppb). Based on these results, we conclude that short-term use of carbaryl for flea control on prairie dogs does not pose a hazard of relay toxicity in black-footed ferrets.

Performance Evaluation of Relay Selection Schemes in Beacon-Assisted Dual-Hop Cognitive Radio Wireless Sensor Networks under Impact of Hardware Noises.

PubMed

Hieu, Tran Dinh; Duy, Tran Trung; Dung, Le The; Choi, Seong Gon

2018-06-05

To solve the problem of energy constraints and spectrum scarcity for cognitive radio wireless sensor networks (CR-WSNs), an underlay decode-and-forward relaying scheme is considered, where the energy constrained secondary source and relay nodes are capable of harvesting energy from a multi-antenna power beacon (PB) and using that harvested energy to forward the source information to the destination. Based on the time switching receiver architecture, three relaying protocols, namely, hybrid partial relay selection (H-PRS), conventional opportunistic relay selection (C-ORS), and best opportunistic relay selection (B-ORS) protocols are considered to enhance the end-to-end performance under the joint impact of maximal interference constraint and transceiver hardware impairments. For performance evaluation and comparison, we derive the exact and asymptotic closed-form expressions of outage probability (OP) and throughput (TP) to provide significant insights into the impact of our proposed protocols on the system performance over Rayleigh fading channel. Finally, simulation results validate the theoretical results.

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.

Illustration of distributed generation effects on protection system coordination

NASA Astrophysics Data System (ADS)

Alawami, Hussain Adnan

Environmental concerns, market forces, and emergence of new technologies have recently resulted in restructuring electric utility from vertically integrated networks to competitive deregulated entities. Distributed generation (DG) is playing a major role in such deregulated markets. When they are installed in small amounts and small sizes, their impacts on the system may be negligible. When their penetration levels increase as well as their sizes, however, they may start affecting the system performance from more than one aspect. Power system protection needs to be re-assessed after the emergence of DG. This thesis attempts to illustrate the impact of DG on the power system protection coordination. It will study the operation of the impedance relays, fuses, reclosers and overcurrent relays when a DG is added to the distribution network. Different DG sizes, distances from the network and locations within the distribution system will be considered. Power system protection coordination is very sensitive to the DG size where it is not for the DG distance. DG location has direct impact on the operation of the protective devices especially when it is inserted in the middle point of the distribution system. Key Words, Distributed Generation, Impedance relay, fuses, reclosers, overcurrent relays, power system protection coordination.

PID Tuning Using Extremum Seeking

DOE Office of Scientific and Technical Information (OSTI.GOV)

Killingsworth, N; Krstic, M

2005-11-15

Although proportional-integral-derivative (PID) controllers are widely used in the process industry, their effectiveness is often limited due to poor tuning. Manual tuning of PID controllers, which requires optimization of three parameters, is a time-consuming task. To remedy this difficulty, much effort has been invested in developing systematic tuning methods. Many of these methods rely on knowledge of the plant model or require special experiments to identify a suitable plant model. Reviews of these methods are given in [1] and the survey paper [2]. However, in many situations a plant model is not known, and it is not desirable to openmore » the process loop for system identification. Thus a method for tuning PID parameters within a closed-loop setting is advantageous. In relay feedback tuning [3]-[5], the feedback controller is temporarily replaced by a relay. Relay feedback causes most systems to oscillate, thus determining one point on the Nyquist diagram. Based on the location of this point, PID parameters can be chosen to give the closed-loop system a desired phase and gain margin. An alternative tuning method, which does not require either a modification of the system or a system model, is unfalsified control [6], [7]. This method uses input-output data to determine whether a set of PID parameters meets performance specifications. An adaptive algorithm is used to update the PID controller based on whether or not the controller falsifies a given criterion. The method requires a finite set of candidate PID controllers that must be initially specified [6]. Unfalsified control for an infinite set of PID controllers has been developed in [7]; this approach requires a carefully chosen input signal [8]. Yet another model-free PID tuning method that does not require opening of the loop is iterative feedback tuning (IFT). IFT iteratively optimizes the controller parameters with respect to a cost function derived from the output signal of the closed-loop system, see [9]. This method is based on the performance of the closed-loop system during a step response experiment [10], [11]. In this article we present a method for optimizing the step response of a closed-loop system consisting of a PID controller and an unknown plant with a discrete version of extremum seeking (ES). Specifically, ES is used to minimize a cost function similar to that used in [10], [11], which quantifies the performance of the PID controller. ES, a non-model-based method, iteratively modifies the arguments (in this application the PID parameters) of a cost function so that the output of the cost function reaches a local minimum or local maximum. In the next section we apply ES to PID controller tuning. We illustrate this technique through simulations comparing the effectiveness of ES to other PID tuning methods. Next, we address the importance of the choice of cost function and consider the effect of controller saturation. Furthermore, we discuss the choice of ES tuning parameters. Finally, we offer some conclusions.« less

Libration Point Navigation Concepts Supporting the Vision for Space Exploration

NASA Technical Reports Server (NTRS)

Carpenter, J. Russell; Folta, David C.; Moreau, Michael C.; Quinn, David A.

2004-01-01

This work examines the autonomous navigation accuracy achievable for a lunar exploration trajectory from a translunar libration point lunar navigation relay satellite, augmented by signals from the Global Positioning System (GPS). We also provide a brief analysis comparing the libration point relay to lunar orbit relay architectures, and discuss some issues of GPS usage for cis-lunar trajectories.

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…

Downlink Cooperative Broadcast Transmission Based on Superposition Coding in a Relaying System for Future Wireless Sensor Networks.

PubMed

Liu, Yang; Han, Guangjie; Shi, Sulong; Li, Zhengquan

2018-06-20

This study investigates the superiority of cooperative broadcast transmission over traditional orthogonal schemes when applied in a downlink relaying broadcast channel (RBC). Two proposed cooperative broadcast transmission protocols, one with an amplify-and-forward (AF) relay, and the other with a repetition-based decode-and-forward (DF) relay, are investigated. By utilizing superposition coding (SupC), the source and the relay transmit the private user messages simultaneously instead of sequentially as in traditional orthogonal schemes, which means the channel resources are reused and an increased channel degree of freedom is available to each user, hence the half-duplex penalty of relaying is alleviated. To facilitate a performance evaluation, theoretical outage probability expressions of the two broadcast transmission schemes are developed, based on which, we investigate the minimum total power consumption of each scheme for a given traffic requirement by numerical simulation. The results provide details on the overall system performance and fruitful insights on the essential characteristics of cooperative broadcast transmission in RBCs. It is observed that better overall outage performances and considerable power gains can be obtained by utilizing cooperative broadcast transmissions compared to traditional orthogonal schemes.

Joint terminals and relay optimization for two-way power line information exchange systems with QoS constraints

NASA Astrophysics Data System (ADS)

Wu, Xiaolin; Rong, Yue

2015-12-01

The quality-of-service (QoS) criteria (measured in terms of the minimum capacity requirement in this paper) are very important to practical indoor power line communication (PLC) applications as they greatly affect the user experience. With a two-way multicarrier relay configuration, in this paper we investigate the joint terminals and relay power optimization for the indoor broadband PLC environment, where the relay node works in the amplify-and-forward (AF) mode. As the QoS-constrained power allocation problem is highly non-convex, the globally optimal solution is computationally intractable to obtain. To overcome this challenge, we propose an alternating optimization (AO) method to decompose this problem into three convex/quasi-convex sub-problems. Simulation results demonstrate the fast convergence of the proposed algorithm under practical PLC channel conditions. Compared with the conventional bidirectional direct transmission (BDT) system, the relay-assisted two-way information exchange (R2WX) scheme can meet the same QoS requirement with less total power consumption.

The Role of Remotely Sensed and Relayed Data in the Delaware River Basin

NASA Technical Reports Server (NTRS)

Paulson, R. W.

1971-01-01

The planned integration of the existing water quality monitoring and data processing systems in the Delaware River Basin with a data relay experiment proposed for the ERTS-1 is discussed. The experiment is designed to use ERTS-1 as a data relay link for a maximum of 20 hydrologic stations in the basin, including stream gaging, reservoir level, ground water level, and water quality monitoring stations. This experiment has the potential for reducing the time lag between data collection and dissemination to less than 12 hours. The experiment will also provide impetus to develop an operational system of real time data processing and dissemination to handle the large quantity of data that will be obtained from the stations in the basin. The results of this experiment will demonstrate the relative merits of satellite relay of data versus conventional means of data telemetry and will provide a basis for the development of operational satellite relay of hydrologic data.

Ground wave emergency network final operational capability: Environmental assessment for northwestern Nebraska relay node, site number RN 8C930NE

NASA Astrophysics Data System (ADS)

1993-02-01

The Ground Wave Emergency Network (GWEN) is a radio communication system designed to relay emergency messages between strategic military areas in the continental United States. The system is immune to the effects of high-altitude electromagnetic pulse (HEMP) energy surges caused by nuclear bursts in the ionosphere that would disrupt conventional communications equipment such as telephones and shortwave radios. A failure of such equipment would prevent timely communications among top military and civilian leaders and strategic Air Force locations and prevent U.S. assessment and retaliation during an attack. GWEN is an essential part of a defense modernization program to upgrade and improve our nation's communications system, thereby strengthening deterrence. The GWEN system consists of a network of relay nodes, receive-only stations, and input/output stations. Each relay node, such as the one proposed in northwestern Nebraska, consists of a guyed radio tower facility similar to those used by commercial AM broadcast transmitters.

Ground wave emergency network environmental assessment for northwestern Colorado relay node site number RN 8C924CO

NASA Astrophysics Data System (ADS)

1993-02-01

The Ground Wave Emergency Network (GWEN) is a radio communication system designed to relay emergency messages between strategic military areas in the continental United States. The system is immune to the effects of high-altitude electromagnetic pulse (HEMP) energy surges caused by nuclear bursts in the ionosphere that would disrupt conventional communications equipment such as telephones and shortwave radios. A failure of such equipment would prevent timely communications among top military and civilian leaders and strategic Air Force locations and prevent U.S. assessment and retaliation during an attack. GWEN is an essential part of a defense modernization program to upgrade and improve our nation's communications system, thereby strengthening deterrence. The GWEN system consists of a network of relay nodes, receive-only stations, and input/output stations. Each relay node, such as the one proposed in southern Nevada consists of a guyed radio tower facility similar to those used by commercial AM broadcast transmitters.

Ground wave emergency network final operational capability: Environmental assessment for southern Nevada relay node site number RN 8W918NV

NASA Astrophysics Data System (ADS)

1993-03-01

The Ground Wave Emergency Network (GWEN) is a radio communication system designed to relay emergency messages between strategic military areas in the continental United States. The system is immune to the effects of high-altitude electromagnetic pulse (HEMP) energy surges caused by nuclear bursts in the ionosphere that would disrupt conventional communications equipment such as telephones and shortwave radios. A failure of such equipment would prevent timely communications among top military and civilian leaders and strategic Air Force locations and prevent U.S. assessment and retaliation during an attack. GWEN is an essential part of a defense modernization program to upgrade and improve our nation's communications system, thereby strengthening deterrence. The GWEN system consists of a network of relay nodes, receive-only stations, and input/output stations. Each relay node, such as the one proposed in southern Nevada consists of a guyed radio tower facility similar to those used by commercial AM broadcast transmitters.

The development and progress of XeCl Excimer laser system

NASA Astrophysics Data System (ADS)

Zhang, Yongsheng; Ma, Lianying; Wang, Dahui; Zhao, Xueqing; Zhu, Yongxiang; Hu, Yun; Qian, Hang; Shao, Bibo; Yi, Aiping; Liu, Jingru

2015-05-01

A large angularly multiplexed XeCl Excimer laser system is under development at the Northwest Institute of Nuclear Technology (NINT). It is designed to explore the technical issues of uniform and controllable target illumination. Short wavelength, uniform and controllable target illumination is the fundamental requirement of high energy density physics research using large laser facility. With broadband, extended light source and multi-beam overlapping techniques, rare gas halide Excimer laser facility will provide uniform target illumination theoretically. Angular multiplexing and image relay techniques are briefly reviewed and some of the limitations are examined to put it more practical. The system consists of a commercial oscillator front end, three gas discharge amplifiers, two electron beam pumped amplifiers and the optics required to relay, encode and decode the laser beam. An 18 lens array targeting optics direct and focus the laser in the vacuum target chamber. The system is operational and currently undergoing tests. The total 18 beams output energy is more than 100J and the pulse width is 7ns (FWHM), the intensities on the target will exceed 1013W/cm2. The aberration of off-axis imaging optics at main amplifier should be minimized to improve the final image quality at the target. Automatic computer controlled alignment of the whole system is vital to efficiency and stability of the laser system, an array of automatic alignment model is under test and will be incorporated in the system soon.

Outage analysis of relay-assisted underwater wireless optical communication systems

NASA Astrophysics Data System (ADS)

Tabeshnezhad, Azadeh; Pourmina, Mohammad Ali

2017-12-01

In this paper, we theoretically evaluate the outage probabilities of underwater wireless optical communication (UWOC) systems. Our derivations are general as the channel model under consideration takes into account all of the channel degrading effects, namely absorption, scattering, and turbulence-induced fading. We numerically show that the UWOC systems, due to the severe channel impairments, cannot typically support longer link ranges than 100 m. Therefore, in this paper, in order to increase the transmission reliability and hence extend the viable communication range of UWOC systems, we apply decode-and-forward (DF) relay-assisted communications either in the form of multi-hop transmission, where multiple intermediate relays are serially employed between the source and destination, or parallel relaying in which multiple DF relays are distributed among the source-to-destination path to cooperate in the end-to-end transmission. Our numerical results reveal that multi-hop transmission, owing to the distance-dependency of all of the channel degrading effects, can tremendously improve the end-to-end outage probability and increase the accessible link ranges to hundreds of meter. For example, a dual-hop transmission in a 45 m coastal water link can provide up to 41 dB performance improvement at the outage probability of 10-9.

Application of a microcomputer-based system to control and monitor bacterial growth.

PubMed

Titus, J A; Luli, G W; Dekleva, M L; Strohl, W R

1984-02-01

A modular microcomputer-based system was developed to control and monitor various modes of bacterial growth. The control system was composed of an Apple II Plus microcomputer with 64-kilobyte random-access memory; a Cyborg ISAAC model 91A multichannel analog-to-digital and digital-to-analog converter; paired MRR-1 pH, pO(2), and foam control units; and in-house-designed relay, servo control, and turbidimetry systems. To demonstrate the flexibility of the system, we grew bacteria under various computer-controlled and monitored modes of growth, including batch, turbidostat, and chemostat systems. The Apple-ISAAC system was programmed in Labsoft BASIC (extended Applesoft) with an average control program using ca. 6 to 8 kilobytes of memory and up to 30 kilobytes for datum arrays. This modular microcomputer-based control system was easily coupled to laboratory scale fermentors for a variety of fermentations.

Application of a Microcomputer-Based System to Control and Monitor Bacterial Growth

PubMed Central

Titus, Jeffrey A.; Luli, Gregory W.; Dekleva, Michael L.; Strohl, William R.

1984-01-01

A modular microcomputer-based system was developed to control and monitor various modes of bacterial growth. The control system was composed of an Apple II Plus microcomputer with 64-kilobyte random-access memory; a Cyborg ISAAC model 91A multichannel analog-to-digital and digital-to-analog converter; paired MRR-1 pH, pO2, and foam control units; and in-house-designed relay, servo control, and turbidimetry systems. To demonstrate the flexibility of the system, we grew bacteria under various computer-controlled and monitored modes of growth, including batch, turbidostat, and chemostat systems. The Apple-ISAAC system was programmed in Labsoft BASIC (extended Applesoft) with an average control program using ca. 6 to 8 kilobytes of memory and up to 30 kilobytes for datum arrays. This modular microcomputer-based control system was easily coupled to laboratory scale fermentors for a variety of fermentations. PMID:16346462

Enhanced networks operations using the X Window System

NASA Technical Reports Server (NTRS)

Linares, Irving

1993-01-01

We propose an X Window Graphical User Interface (GUI) which is tailored to the operations of NASA GSFC's Network Control Center (NCC), the NASA Ground Terminal (NGT), the White Sands Ground Terminal (WSGT), and the Second Tracking and Data Relay Satellite System (TDRSS) Ground Terminal (STGT). The proposed GUI can also be easily extended to other Ground Network (GN) Tracking Stations due to its standardized nature.

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.

Taped Random Spectra for Reliability Demonstration Testing

DTIC Science & Technology

1981-04-01

circuit , barrier strip terminals 9A and 9B. Closure of the normally-open contacts provides the gate current necessary to trigger the control TRIAC ... Circuit contains a TRIAC , DIAC, Reed Relay (R3) and the Tape Running Relay Driver. The Cam on/off switching is accomplished through the barrier strip...2-25 2I; Input Power Circuit .. .. .... ...... ...... ...... ........... 2-26 2-13 Typical Control Circuit

Application of long-term simulation programs for analysis of system islanding

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sancha, J.L.; Llorens, M.L.; Moreno, J.M.

1997-02-01

This paper describes the main results and conclusions from the application of two different long-term stability programs to the analysis of a system islanding scenario for a study case developed by Red Electrica de Espana (REE), based on the Spanish system. Two main goals were to evaluate the performance of both the influence of some important control and protection elements (tie-line loss-of-synchronism relays, underfrequency load-shedding, load-frequency control, and power plant dynamics). Conclusions about modeling and computational requirements for system islanding (frequency) scenarios and use of long-term stability programs are presented.

Satellite-aided coastal zone monitoring and vessel traffic system

NASA Technical Reports Server (NTRS)

Baker, J. L.

1981-01-01

The development and demonstration of a coastal zone monitoring and vessel traffic system is described. This technique uses a LORAN-C navigational system and relays signals via the ATS-3 satellite to a computer driven color video display for real time control. Multi-use applications of the system to search and rescue operations, coastal zone management and marine safety are described. It is emphasized that among the advantages of the system are: its unlimited range; compatibility with existing navigation systems; and relatively inexpensive cost.

Rack protection monitor

DOEpatents

Orr, Stanley G.

2000-01-01

A hardwired, fail-safe rack protection monitor utilizes electromechanical relays to respond to the detection by condition sensors of abnormal or alarm conditions (such as smoke, temperature, wind or water) that might adversely affect or damage equipment being protected. When the monitor is reset, the monitor is in a detection mode with first and second alarm relay coils energized. If one of the condition sensors detects an abnormal condition, the first alarm relay coil will be de-energized, but the second alarm relay coil will remain energized. This results in both a visual and an audible alarm being activated. If a second alarm condition is detected by another one of the condition sensors while the first condition sensor is still detecting the first alarm condition, both the first alarm relay coil and the second alarm relay coil will be de-energized. With both the first and second alarm relay coils de-energized, both a visual and an audible alarm will be activated. In addition, power to the protected equipment will be terminated and an alarm signal will be transmitted to an alarm central control. The monitor can be housed in a separate enclosure so as to provide an interface between a power supply for the protected equipment and the protected equipment.

A scheduling model for the aerial relay system

NASA Technical Reports Server (NTRS)

Ausrotas, R. A.; Liu, E. W.

1980-01-01

The ability of the Aerial Relay System to handle the U.S. transcontinental large hub passenger flow was analyzed with a flexible, interactive computer model. The model incorporated city pair time of day demand and a demand allocation function which assigned passengers to their preferred flights.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Samaan, Nader A.; Dagle, Jeffery E.; Makarov, Yuri V.

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. Thismore » is useful for simulating cascading outages.« less

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.

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.

Paperless Work Package Application

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kilgore, Jr., William R.; Morrell, Jr., Otto K.; Morrison, Dan

2014-07-31

Paperless Work Package (PWP) System is a computer program process that takes information from Asset Suite, provides a platform for other electronic inputs, Processes the inputs into an electronic package that can be downloaded onto an electronic work tablet or laptop computer, provides a platform for electronic inputs into the work tablet, and then transposes those inputs back into Asset Suite and to permanent SRS records. The PWP System will basically eliminate paper requirements from the maintenance work control system. The program electronically relays the instructions given by the planner to work on a piece of equipment which is currentlymore » relayed via a printed work package. The program does not control/approve what is done. The planner will continue to plan the work package, the package will continue to be routed, approved, and scheduled. The supervisor reviews and approves the work to be performed and assigns work to individuals or to a work group. (The supervisor conducts pre job briefings with the workers involved in the job) The Operations Manager (Work Controlling Entity) approves the work package electronically for the work that will be done in his facility prior to work starting. The PWP System will provide the package in an electronic form. All the reviews, approvals, and safety measures taken by people outside the electronic package does not change from the paper driven work packages.« less

Data-Logger Interface And Test Controller

NASA Technical Reports Server (NTRS)

Burch, Donnie R.

1995-01-01

Data-logger interface and test controller developed to enable automation of tests in conjunction with data-acquisition functions performed by data loggers that have output-switching capabilities. Includes relay logic circuits that remain deenergized until out-of-tolerance condition on any data channel discovered. Designed to be connected to Fluke model 2286A (or equivalent) data-logger system, which features 3 control channels with 6 data inputs per channel. Includes elapsed-time counter that keeps track of power outages.

Relay discovery and selection for large-scale P2P streaming

PubMed Central

Zhang, Chengwei; Wang, Angela Yunxian

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. PMID:28410384

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.

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…

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.

Artist concept of the STS-43 Tracking and Data Relay Satellite E (TDRS-E)

NASA Image and Video Library

1990-06-22

Artist concept shows the Tracking and Data Relay Satellite E (TDRS-E) augmenting a sophisticated TDRS system (TDRSS) communications network after deployment during STS-43 from Atlantis, Orbiter Vehicle (OV) 104. TDRS, built by TRW, will be placed in a geosynchronous orbit and after onorbit testing, which requires several weeks, will be designated TDRS-5. The communications satellite will replace TDRS-3 at 174 degrees West longitude. The backbone of NASA's space-to-ground communications, the TDRSs have increased NASA's ability to send and receive data to spacecraft in low-earth orbit to more than 85 percent of the time. Before TDRS, NASA relied solely on a system of ground stations that permitted communications only 15 percent of the time. Increased coverage has allowed onorbit repairs, live television broadcast from space and continuous dialogues between astronaut crews and ground control during critical periods such as Space Shuttle landings.

Tracking and data relay satellite system (TDRSS) capabilities

NASA Astrophysics Data System (ADS)

Spearing, R. E.

1985-10-01

The Tracking and Data Relay Satellite System (TDRSS) is the latest implementation to tracking and data acquisition network for near-earth orbiting satellite support designed to meet the requirements of the current and projected (to the year 2000) satellite user community. The TDRSS consists of a space segment (SS) and a ground segment (GS) that fit within NASA's Space Network (SN) complex controlled at the Goddard Space Flight Center. The SS currently employs a single satellite, TDRS-1, with two additional satellites to be deployed in January 1986 and July 1986. The GS contains the communications and equipment required to manage the three TDR satellites and to transmit and receive information to and from TDRSS user satellites. Diagrams and tables illustrating the TDRSS signal characteristics, the situation of TDRSS within the SN, the SN operations and element interrelationships, as well as future plans for new missions are included.

Tracking and data relay satellite system (TDRSS) capabilities

NASA Technical Reports Server (NTRS)

Spearing, R. E.

1985-01-01

The Tracking and Data Relay Satellite System (TDRSS) is the latest implementation to tracking and data acquisition network for near-earth orbiting satellite support designed to meet the requirements of the current and projected (to the year 2000) satellite user community. The TDRSS consists of a space segment (SS) and a ground segment (GS) that fit within NASA's Space Network (SN) complex controlled at the Goddard Space Flight Center. The SS currently employs a single satellite, TDRS-1, with two additional satellites to be deployed in January 1986 and July 1986. The GS contains the communications and equipment required to manage the three TDR satellites and to transmit and receive information to and from TDRSS user satellites. Diagrams and tables illustrating the TDRSS signal characteristics, the situation of TDRSS within the SN, the SN operations and element interrelationships, as well as future plans for new missions are included.

[Research on the High Efficiency Data Communication Repeater Based on STM32F103].

PubMed

Zhang, Yahui; Li, Zheng; Chen, Guangfei

2015-11-01

To improve the radio frequency (RF) transmission distance of the wireless terminal of the medical internet of things (LOT), to realize the real-time and efficient data communication, the intelligent relay system based on STM32F103 single chip microcomputer (SCM) is proposed. The system used nRF905 chip to achieve the collection, of medical and health information of patients in the 433 MHz band, used SCM to control the serial port to Wi-Fi module to transmit information from 433 MHz to 2.4 GHz wireless Wi-Fi band, and used table look-up algorithm of ready list to improve the efficiency of data communications. The design can realize real-time and efficient data communication. The relay which is easy to use with high practical value can extend the distance and mode of data transmission and achieve real-time transmission of data.

[Effects of reduced N application rate on yield and nutrient uptake and utilization in maize-soybean relay strip intercropping system].

PubMed

Yong, Tai-Wen; Liu, Xiao-Ming; Wen-Yu, Liu; Su, Ben-Ying; Song, Chun; Yang, Feng; Wang, Xiao-Chun; Yang, Wen-Yu

2014-02-01

A field experiment with three N application rates (0, 180, 240 N kg x hm(-2), representing zero, reduced and conventional N application, respectively) and three planting patterns (maize monoculture, soybean monoculture and maize-soybean relay strip intercropping) was conducted to reveal the effects of cropping patterns and N application rates on yield, nutrient uptake and nitrogen use efficiency of maize and soybean. The results showed that the grain yield, N, P and K uptake and harvest index of the intercropped maize reduced slightly compared with the monoculture maize, however these indices of the intercropped soybean increased significantly compared with the monoculture. With the increase in nitrogen fertilizer application, the excellence of relay strip intercropping was weakened in the maize-soybean intercropping system. The grain yield, economic coefficient, N, P and K uptake, harvest index, N agronomy efficiency and N uptake efficiency of maize and soybean increased significantly at the reduced nitrogen rate (180 N kg x hm(-2)), but the rate of soil N contribution declined, compared with the conventional rate of N application by local farmers (240 N kg x hm(-2)). In the reduced nitrogen rate treatment, total soil N and P contents of the maize strip reduced, whereas the total soil N, P and K contents of soybean strip and the total K content of maize strip increased compared with the zero N application treatment. With the reduced N application, the annual total grain yield, N, P and K uptake of above-ground biomass in the maize-soybean relay strip intercropping system were higher than in the monoculture, and the land equivalent ratio (LER) was 2.28. N uptake efficiency of maize in the relay strip intercropping system was 20.2% higher than in the maize monoculture, and the index of soybean was 30.5% lower than in the monoculture. The rate of soil N contribution in the relay strip intercropping system was 20.0% and 8.8% lower than in the maize and soybean monoculture, respectively. The reduced N application in the maize-soybean relay strip intercropping system was helpful to promote annual grain yield and improve N utilization efficiency.

Bubbling in delay-coupled lasers.

PubMed

Flunkert, V; D'Huys, O; Danckaert, J; Fischer, I; Schöll, E

2009-06-01

We theoretically study chaos synchronization of two lasers which are delay coupled via an active or a passive relay. While the lasers are synchronized, their dynamics is identical to a single laser with delayed feedback for a passive relay and identical to two delay-coupled lasers for an active relay. Depending on the coupling parameters the system exhibits bubbling, i.e., noise-induced desynchronization, or on-off intermittency. We associate the desynchronization dynamics in the coherence collapse and low-frequency fluctuation regimes with the transverse instability of some of the compound cavity's antimodes. Finally, we demonstrate how, by using an active relay, bubbling can be suppressed.

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 order exhibited in the outage curve converges to 1 when the bit streams are not fully correlated. Moreover, the Slepian-Wolf outage probability is proved to be smaller than that of the 2nd order maximum ratio combining (MRC) diversity, if the average SNRs of the two independent links are the same. Exact as well as asymptotic expressions of the outage probability are theoretically derived in the article. In addition, the theoretical outage results are compared with the frame-error-rate (FER) curves, obtained by a series of simulations for the Slepian-Wolf relay system based on bit-interleaved coded modulation with iterative detection (BICM-ID). It is shown that the FER curves exhibit the same tendency as the theoretical results.

Relay NBS Graft with the Plus Delivery System to Improve Deployment in Aortic Arch with Small Radius Curve

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ferro, Carlo; Rossi, Umberto G., E-mail: urossi76@hotmail.com; Seitun, Sara

The purpose of this report is to describe deployment of the Relay NBS Thoracic Stent Graft with the Plus Delivery System (Bolton Medical, Sunrise, FL) in a flexible resin arch model with a 15-mm radius curve as well as our preliminary clinical results. The Relay NBS graft with the Plus Delivery System was evaluated by way of bench testing, which was performed with stent grafts with diameters ranging from 24 to 46 mm and lengths ranging from 100 to 250 mm in flexible resin arch models with a 15-mm arch radius of curvature. The deployment sequence was analyzed. The Relaymore » NBS graft with the Plus Delivery System was deployed in two patients, respectively, having a 6.5-cm penetrating aortic ulcer of the proximal third of the descending thoracic aorta and a DeBakey type-I aortic dissection with chronic false lumen dilatation after surgery due to an entry site at the distal thoracic aorta. Bench tests showed proper conformation and apposition of the Relay NBS graft with the Plus Delivery System in the flexible resin model. This stent graft was deployed successfully into the two patients with a correct orientation of the first stent and without early or late complications. The Relay NBS graft with the Plus Delivery System ensures an optimal conformation and apposition of the first stent in the aortic arch with a small radius of curvature.« less

Fuzzy-Wavelet Based Double Line Transmission System Protection Scheme in the Presence of SVC

NASA Astrophysics Data System (ADS)

Goli, Ravikumar; Shaik, Abdul Gafoor; Tulasi Ram, Sankara S.

2015-06-01

Increasing the power transfer capability and efficient utilization of available transmission lines, improving the power system controllability and stability, power oscillation damping and voltage compensation have made strides and created Flexible AC Transmission (FACTS) devices in recent decades. Shunt FACTS devices can have adverse effects on distance protection both in steady state and transient periods. Severe under reaching is the most important problem of relay which is caused by current injection at the point of connection to the system. Current absorption of compensator leads to overreach of relay. This work presents an efficient method based on wavelet transforms, fault detection, classification and location using Fuzzy logic technique which is almost independent of fault impedance, fault distance and fault inception angle. The proposed protection scheme is found to be fast, reliable and accurate for various types of faults on transmission lines with and without Static Var compensator at different locations and with various incidence angles.

Digital transceiver design for two-way AF-MIMO relay systems with imperfect CSI

NASA Astrophysics Data System (ADS)

Hu, Chia-Chang; Chou, Yu-Fei; Chen, Kui-He

2013-09-01

In the paper, combined optimization of the terminal precoders/equalizers and single-relay precoder is proposed for an amplify-and-forward (AF) multiple-input multiple-output (MIMO) two-way single-relay system with correlated channel uncertainties. Both terminal transceivers and relay precoding matrix are designed based on the minimum mean square error (MMSE) criterion when terminals are unable to erase completely self-interference due to imperfect correlated channel state information (CSI). This robust joint optimization problem of beamforming and precoding matrices under power constraints belongs to neither concave nor convex so that a nonlinear matrix-form conjugate gradient (MCG) algorithm is applied to explore local optimal solutions. Simulation results show that the robust transceiver design is able to overcome effectively the loss of bit-error-rate (BER) due to inclusion of correlated channel uncertainties and residual self-interference.

User guide to a command and control system; a part of a prelaunch wind monitoring program

NASA Technical Reports Server (NTRS)

Cowgill, G. R.

1976-01-01

A set of programs called Command and Control System (CCS), intended as a user manual, is described for the operation of CCS by the personnel supporting the wind monitoring portion of the launch mission. Wind data obtained by tracking balloons is sent by electronic means using telephone lines to other locations. Steering commands are computed from a system called ADDJUST for the on-board computer and relays this data. Data are received and automatically stored in a microprocessor, then via a real time program transferred to the UNIVAC 1100/40 computer. At this point the data is available to be used by the Command and Control system.

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

47 CFR 90.469 - Unattended operation.

Code of Federal Regulations, 2010 CFR

2010-10-01

... MOBILE RADIO SERVICES Transmitter Control § 90.469 Unattended operation. (a) Subject to the provisions of §§ 90.243, 90.245, and 90.247, mobile relay, fixed relay, and mobile repeater stations are authorized... where they are activated by either electrical or mechanical devices, provided the licensee adopts...

Structural evolution of fault zones in sandstone by multiple deformation mechanisms: Moab fault, southeast Utah

USGS Publications Warehouse

Davatzes, N.C.; Eichhubl, P.; Aydin, A.

2005-01-01

Faults in sandstone are frequently composed of two classes of structures: (1) deformation bands and (2) joints and sheared joints. Whereas the former structures are associated with cataclastic deformation, the latter ones represent brittle fracturing, fragmentation, and brecciation. We investigated the distribution of these structures, their formation, and the underlying mechanical controls for their occurrence along the Moab normal fault in southeastern Utah through the use of structural mapping and numerical elastic boundary element modeling. We found that deformation bands occur everywhere along the fault, but with increased density in contractional relays. Joints and sheared joints only occur at intersections and extensional relays. In all locations , joints consistently overprint deformation bands. Localization of joints and sheared joints in extensional relays suggests that their distribution is controlled by local variations in stress state that are due to mechanical interaction between the fault segments. This interpretation is consistent with elastic boundary element models that predict a local reduction in mean stress and least compressive principal stress at intersections and extensional relays. The transition from deformation band to joint formation along these sections of the fault system likely resulted from the combined effects of changes in remote tectonic loading, burial depth, fluid pressure, and rock properties. In the case of the Moab fault, we conclude that the structural heterogeneity in the fault zone is systematically related to the geometric evolution of the fault, the local state of stress associated with fault slip , and the remote loading history. Because the type and distribution of structures affect fault permeability and strength, our results predict systematic variations in these parameters with fault evolution. ?? 2004 Geological Society of America.

Energy Efficient Medium Access Control Protocol for Clustered Wireless Sensor Networks with Adaptive Cross-Layer Scheduling.

PubMed

Sefuba, Maria; Walingo, Tom; Takawira, Fambirai

2015-09-18

This paper presents an Energy Efficient Medium Access Control (MAC) protocol for clustered wireless sensor networks that aims to improve energy efficiency and delay performance. The proposed protocol employs an adaptive cross-layer intra-cluster scheduling and an inter-cluster relay selection diversity. The scheduling is based on available data packets and remaining energy level of the source node (SN). This helps to minimize idle listening on nodes without data to transmit as well as reducing control packet overhead. The relay selection diversity is carried out between clusters, by the cluster head (CH), and the base station (BS). The diversity helps to improve network reliability and prolong the network lifetime. Relay selection is determined based on the communication distance, the remaining energy and the channel quality indicator (CQI) for the relay cluster head (RCH). An analytical framework for energy consumption and transmission delay for the proposed MAC protocol is presented in this work. The performance of the proposed MAC protocol is evaluated based on transmission delay, energy consumption, and network lifetime. The results obtained indicate that the proposed MAC protocol provides improved performance than traditional cluster based MAC protocols.

Energy Efficient Medium Access Control Protocol for Clustered Wireless Sensor Networks with Adaptive Cross-Layer Scheduling

PubMed Central

Sefuba, Maria; Walingo, Tom; Takawira, Fambirai

2015-01-01

This paper presents an Energy Efficient Medium Access Control (MAC) protocol for clustered wireless sensor networks that aims to improve energy efficiency and delay performance. The proposed protocol employs an adaptive cross-layer intra-cluster scheduling and an inter-cluster relay selection diversity. The scheduling is based on available data packets and remaining energy level of the source node (SN). This helps to minimize idle listening on nodes without data to transmit as well as reducing control packet overhead. The relay selection diversity is carried out between clusters, by the cluster head (CH), and the base station (BS). The diversity helps to improve network reliability and prolong the network lifetime. Relay selection is determined based on the communication distance, the remaining energy and the channel quality indicator (CQI) for the relay cluster head (RCH). An analytical framework for energy consumption and transmission delay for the proposed MAC protocol is presented in this work. The performance of the proposed MAC protocol is evaluated based on transmission delay, energy consumption, and network lifetime. The results obtained indicate that the proposed MAC protocol provides improved performance than traditional cluster based MAC protocols. PMID:26393608

Intelligent Power Swing Detection Scheme to Prevent False Relay Tripping Using S-Transform

NASA Astrophysics Data System (ADS)

Mohamad, Nor Z.; Abidin, Ahmad F.; Musirin, Ismail

2014-06-01

Distance relay design is equipped with out-of-step tripping scheme to ensure correct distance relay operation during power swing. The out-of-step condition is a consequence result from unstable power swing. It requires proper detection of power swing to initiate a tripping signal followed by separation of unstable part from the entire power system. The distinguishing process of unstable swing from stable swing poses a challenging task. This paper presents an intelligent approach to detect power swing based on S-Transform signal processing tool. The proposed scheme is based on the use of S-Transform feature of active power at the distance relay measurement point. It is demonstrated that the proposed scheme is able to detect and discriminate the unstable swing from stable swing occurring in the system. To ascertain validity of the proposed scheme, simulations were carried out with the IEEE 39 bus system and its performance has been compared with the wavelet transform-based power swing detection scheme.

Absolute Stability Analysis of a Phase Plane Controlled Spacecraft

NASA Technical Reports Server (NTRS)

Jang, Jiann-Woei; Plummer, Michael; Bedrossian, Nazareth; Hall, Charles; Jackson, Mark; Spanos, Pol

2010-01-01

Many aerospace attitude control systems utilize phase plane control schemes that include nonlinear elements such as dead zone and ideal relay. To evaluate phase plane control robustness, stability margin prediction methods must be developed. Absolute stability is extended to predict stability margins and to define an abort condition. A constrained optimization approach is also used to design flex filters for roll control. The design goal is to optimize vehicle tracking performance while maintaining adequate stability margins. Absolute stability is shown to provide satisfactory stability constraints for the optimization.

78 FR 22802 - Airworthiness Directives; the Boeing Company Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-17

... indication system and wiring on each engine; and repetitive operational checks of that installation to detect... wiring. Installation of a second locking gearbox 754 work-hours x $85 per hour = $0 $64,090 system. $64... proposed AD would require replacing certain relays and relay sockets, and doing wiring changes. For certain...

47 CFR 22.1007 - Channels for offshore radiotelephone systems.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 491.550 488.700 491.700 (3) These channels may be assigned for use by relay stations in systems where it would be impractical to provide offshore radiotelephone service without the use of relay stations... protection of life and property. Central Subscriber Central Subscriber 488.825 491.825 488.875 491.875 488...

47 CFR 22.1007 - Channels for offshore radiotelephone systems.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 491.550 488.700 491.700 (3) These channels may be assigned for use by relay stations in systems where it would be impractical to provide offshore radiotelephone service without the use of relay stations... protection of life and property. Central Subscriber Central Subscriber 488.825 491.825 488.875 491.875 488...

Enhanced Positioning Algorithm of ARPS for Improving Accuracy and Expanding Service Coverage

PubMed Central

Lee, Kyuman; Baek, Hoki; Lim, Jaesung

2016-01-01

The airborne relay-based positioning system (ARPS), which employs the relaying of navigation signals, was proposed as an alternative positioning system. However, the ARPS has limitations, such as relatively large vertical error and service restrictions, because firstly, the user position is estimated based on airborne relays that are located in one direction, and secondly, the positioning is processed using only relayed navigation signals. In this paper, we propose an enhanced positioning algorithm to improve the performance of the ARPS. The main idea of the enhanced algorithm is the adaptable use of either virtual or direct measurements of reference stations in the calculation process based on the structural features of the ARPS. Unlike the existing two-step algorithm for airborne relay and user positioning, the enhanced algorithm is divided into two cases based on whether the required number of navigation signals for user positioning is met. In the first case, where the number of signals is greater than four, the user first estimates the positions of the airborne relays and its own initial position. Then, the user position is re-estimated by integrating a virtual measurement of a reference station that is calculated using the initial estimated user position and known reference positions. To prevent performance degradation, the re-estimation is performed after determining its requirement through comparing the expected position errors. If the navigation signals are insufficient, such as when the user is outside of airborne relay coverage, the user position is estimated by additionally using direct signal measurements of the reference stations in place of absent relayed signals. The simulation results demonstrate that a higher accuracy level can be achieved because the user position is estimated based on the measurements of airborne relays and a ground station. Furthermore, the service coverage is expanded by using direct measurements of reference stations for user positioning. PMID:27529252

Enhanced Positioning Algorithm of ARPS for Improving Accuracy and Expanding Service Coverage.

PubMed

Lee, Kyuman; Baek, Hoki; Lim, Jaesung

2016-08-12

The airborne relay-based positioning system (ARPS), which employs the relaying of navigation signals, was proposed as an alternative positioning system. However, the ARPS has limitations, such as relatively large vertical error and service restrictions, because firstly, the user position is estimated based on airborne relays that are located in one direction, and secondly, the positioning is processed using only relayed navigation signals. In this paper, we propose an enhanced positioning algorithm to improve the performance of the ARPS. The main idea of the enhanced algorithm is the adaptable use of either virtual or direct measurements of reference stations in the calculation process based on the structural features of the ARPS. Unlike the existing two-step algorithm for airborne relay and user positioning, the enhanced algorithm is divided into two cases based on whether the required number of navigation signals for user positioning is met. In the first case, where the number of signals is greater than four, the user first estimates the positions of the airborne relays and its own initial position. Then, the user position is re-estimated by integrating a virtual measurement of a reference station that is calculated using the initial estimated user position and known reference positions. To prevent performance degradation, the re-estimation is performed after determining its requirement through comparing the expected position errors. If the navigation signals are insufficient, such as when the user is outside of airborne relay coverage, the user position is estimated by additionally using direct signal measurements of the reference stations in place of absent relayed signals. The simulation results demonstrate that a higher accuracy level can be achieved because the user position is estimated based on the measurements of airborne relays and a ground station. Furthermore, the service coverage is expanded by using direct measurements of reference stations for user positioning.

Tracking and data relay satellite system configuration and tradeoff study. Volume 3: TDRSS configuration and data summary, part 1

NASA Technical Reports Server (NTRS)

1972-01-01

A reference handbook of configuration data and design information is presented. It treats the overall system definition, operations and control, and telecommunication service system including link budgets. A brief description of the user transceiver and ground station is presented. A final section includes a summary description of the TDR spacecraft and all the subsystems. The data presented are largely in tabular form for easy reference.

The Temperature Fuzzy Control System of Barleythe Malt Drying Based on Microcontroller

NASA Astrophysics Data System (ADS)

Gao, Xiaoyang; Bi, Yang; Zhang, Lili; Chen, Jingjing; Yun, Jianmin

The control strategy of temperature and humidity in the beer barley malt drying chamber based on fuzzy logic control was implemented.Expounded in this paper was the selection of parameters for the structure of the regulatory device, as well as the essential design from control rules based on the existing experience. A temperature fuzzy controller was thus constructed using relevantfuzzy logic, and humidity control was achieved by relay, ensured the situation of the humidity to control the temperature. The temperature's fuzzy control and the humidity real-time control were all processed by single chip microcomputer with assembly program. The experimental results showed that the temperature control performance of this fuzzy regulatory system,especially in the ways of working stability and responding speed and so on,was better than normal used PID control. The cost of real-time system was inquite competitive position. It was demonstrated that the system have a promising prospect of extensive application.

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.

Modeling Zone-3 Protection with Generic Relay Models for Dynamic Contingency Analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Qiuhua; Vyakaranam, Bharat GNVSR; Diao, Ruisheng

This paper presents a cohesive approach for calculating and coordinating the settings of multiple zone-3 protections for dynamic contingency analysis. The zone-3 protections are represented by generic distance relay models. A two-step approach for determining zone-3 relay settings is proposed. The first step is to calculate settings, particularly, the reach, of each zone-3 relay individually by iteratively running line open-end fault short circuit analysis; the blinder is also employed and properly set to meet the industry standard under extreme loading conditions. The second step is to systematically coordinate the protection settings of the zone-3 relays. The main objective of thismore » coordination step is to address the over-reaching issues. We have developed a tool to automate the proposed approach and generate the settings of all distance relays in a PSS/E dyr format file. The calculated zone-3 settings have been tested on a modified IEEE 300 system using a dynamic contingency analysis tool (DCAT).« less

117. VIEW OF CABINETS ON EAST SIDE OF LANDLINE INSTRUMENTATION ...

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

117. VIEW OF CABINETS ON EAST SIDE OF LANDLINE INSTRUMENTATION ROOM (206), LSB (BLDG. 751). FEATURES LEFT TO RIGHT: ALTERNATING CURRENT POWER DISTRIBUTION RELAY BOX, AIRBORNE BEACON ELECTRONIC TEST SYSTEM (ABETS), AUTOPILOT CHECKOUT CONTROLS, POWER DISTRIBUTION UNITS. - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

Centralized vs decentralized options for an European Data Relay Satellite system

NASA Astrophysics Data System (ADS)

Saint Aubert, S.; Hervieux, M.; Perbos, J. L.; Saggese, E.; Soprano, C.

1985-10-01

The European Data Relay Satellite (DRS) is now being planned to support future European missions in the nineties and in particular the various elements of the in-orbit infrastructure. Studies are being conducted to investigate the usefulness of the relay system as well as to provide the basis for issuing technical specifications for a development and launch in 1993. This paper presents the results of a study issued by ESA on possible options for a DRS System, concentrating on the comparison between a centralized and a decentralized data distribution concept. After recalling the space programs foreseen in Europe, the paper discusses the architecture and design of the various elements of the System: space segment, DRS ground segment, and user ground segment for different options of data dissemination.

Centralized vs decentralized options for a european data relay satellite system

NASA Astrophysics Data System (ADS)

Aubert, Ph. Saint; Hervieux, M.; Perbos, J. L.; Saggese, E.; Soprano, C.

The European Data Relay Satellite (DRS) is now being planned to support future European missions in the nineties and in particular the various elements of the in-orbit infrastructure. Studies are being conducted to investigate the usefulness of the Relay System as well as to provide the basis for issuing technical specifications for a development and launch in 1993. This paper presents the results of a study issued by ESA on possible options for a DRS System, concentrating on the comparison between a centralized and a decentralized data distribution concept. After recalling the space programmes foreseen in Europe, the paper discusses the architecture and design of the various elements of the System: space segment, DRS ground segment and user ground segment for different options of data dissemination.

Auction-based Security Game for Multiuser Cooperative Networks

NASA Astrophysics Data System (ADS)

Wang, An; Cai, Yueming; Yang, Wendong; Cheng, Yunpeng

2013-04-01

In this paper, we develop an auction-based algorithm to allocate the relay power efficiently to improve the system secrecy rate in a cooperative network, where several source-destination pairs and one cooperative relay are involved. On the one hand, the cooperative relay assists these pairs to transmit under a peak power constraint. On the other hand, the relay is untrusty and is also a passive eavesdropper. The whole auction process is completely distributed and no instantaneous channel state information exchange is needed. We also prove the existence and uniqueness of the Nash Equilibrium (NE) for the proposed power auction game. Moreover, the Pareto optimality is also validated. Simulation results show that our proposed auction-based algorithm can effectively improve the system secrecy rate. Besides, the proposed auction-based algorithm can converge to the unique NE point within a finite number of iterations. More interestingly, we also find that the proposed power auction mechanism is cheat-proof.

Interactions between relay helix and Src homology 1 domain helix (SH1) drive the converter domain rotation during the recovery stroke of myosin II

PubMed Central

Baumketner, Andrij

2012-01-01

Myosin motor protein exists in two alternative conformations, pre-recovery state M* and post-recovery state M**, upon ATP binding. The details of the M*-to-M** transition, known as the recovery stroke to reflect its role as the functional opposite of the force-generating power stroke, remain elusive. The defining feature of the post-recovery state is a kink in the relay helix, a key part of the protein involved in force generation. In this paper we determine the interactions that are responsible for the appearance of the kink. We design a series of computational models that contain three other segments, relay loop, converter domain and Src homology 1 domain helix (SH1), with which relay helix interacts, and determine their structure in accurate replica exchange molecular dynamics simulations in explicit solvent. By conducting an exhaustive combinatorial search among different models we find that: 1) the converter domain must be attached to the relay helix during the transition, so it does not interfere with other parts of the protein, 2) the structure of the relay helix is controlled by SH1 helix. The kink is strongly coupled to the position of SH1 helix. It arises as a result of direct interactions between SH1 and the relay helix and leads to a rotation of the C-terminal part of the relay helix which is subsequently transmitted to the converter domain. PMID:22411190

Development of a multiplexed bypass control system for aerospace batteries

NASA Technical Reports Server (NTRS)

Frank, H. A.

1977-01-01

A breadboard bypass control system was developed to control a battery comprised of 26 JPL-developed negative limited Ni-Cd cells. The system was designed to automatically remove cells from the circuit when their voltages exceeded a fixed limit on charge and fell below a fixed limit on discharge. Major components of the system consisted of a cell voltage monitor, a multiplexing circuit, and individual electromechanical relays for each cell. The system was found to function well in controlling the battery during a simulated 10-month MM-71 mission and a 2-month simulated low earth orbit cycling mission. A flight version of the bypass system was estimated to have a total parts count of 150 and total weight of 1.63 kg. When fully developed, the system shows promise for improving life and reliability of spacecraft batteries.

Evaluation of remote hydrologic data-acquisition systems, west-central Florida

USGS Publications Warehouse

Turner, J.F.; Woodham, W.M.

1980-01-01

The study provides an evaluation of the hydrologic applications of a land-line and two satellite data-relay systems operated during 1977-78 in the Southwest Florida Water Management District. These systems were tested to evaluate operational and reliability characteristics. Telephone lines were used to relay data in the land-line system, and the Geostationary Operational Environmental Satellite (GOES) and Land satellite (Landsat) were used in the satellite system. The land-line system was tested for 15 months at a streamflow site. Accurate data were obtained 94% of the time during the test period. Data losses were attributed to telephone-line interference, low-battery voltage, and vandalism. The GOES system was tested at a rainfall site for 17 months. During this period, 79% of the transmissions received from the station were relayed by the GOES system to the U.S. Geological Survey computer, resulting in successful processing of 88% of all possible rainfall observations. On the average, seven data transmissions were completed each day. The Landsat system was tested at a rainfall site for about 17 months and for about 8 months at a streamflow site. During these periods of operation, only about 2% of all data observations for the stations were successfully relayed by the Landsat system to the U.S. Geological Survey computer. An average of about three data transmissions was completed each day for each site. (USGS).

SNAP 19 Viking Program. Bimonthly technical progress report, February 1980-March 1980

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1980-01-01

Viking 1 Lander power system data has not been available during this reporting period, but summary reports indicate no anomalies in performance. Monitoring and evaluation of Viking 2 Lander power system data continued. Temperature data were similar to those 23 months ago, but combined RTG output power was down by 7 watts from the 75 watts recorded in February of 1978. On February 7, 1980, during a scheduled relay transmission the Lander 2 battery voltage dropped below 26.5 volts. With the orbiter attitude control gas supply nearly depleted and the space network stations required for Voyager encounter with Saturn latermore » this year, the final relay from Viking Lander 2 had been scheduled to take place on April 11. The attempt was made but no data were received. Power system performance data for Pioneer 10 and Pioneer Saturn (initially designated Pioneer 11) were monitored. The estimated RTG system net power was 115 watts for both, Pioneer 10 and Pioneer Saturn. The telemetry signal quality from Pioneer Saturn remains excellent. Pioneer 10, for the first time, shows a loss of signal strength.« less

Polar Satcom System and Related Method

NASA Technical Reports Server (NTRS)

Mitchell, James P. (Inventor)

2016-01-01

A system and method for communication relay via a repeater platform satellite vehicle to a near surface station in the Polar Region is disclosed. A preferred embodiment receives a plurality of positioning and content data from a plurality of constellations of Geosynchronous Equatorial Orbit (GEO) Satellite Vehicles (SAT). Additionally, the system receives a plurality of position, time and altitude data from constellations of available repeater platform (RP) SATs. The system receives a request for content from a near surface station located in an area lacking adequate line-of-sight to the GEO based signal. The system aligns antenna elements onboard the desired RP SATs to amplify and relay the GEO based signal toward the near surface station and vice versa. Additionally, the system commands directional antenna elements onboard the station to send and receive the relayed signal making the GEO based content available to the near surface station.

Air Force Flight Evaluation (Systems) of the A-10A Prototype Aircraft

DTIC Science & Technology

1973-03-01

problem was traced to a defective electrical relay. The relay was replaced and no further trouble was experienced. REMARKS: Only MK-82, BLU-l, and BDU...IMPACT (AfIL-STD-88.,) CATEGORY * 711 LIV ~ ESIABE ~ DMAE SUB3SYSTE (-V DEGRADES [3MAINTENANCE R INJURY PERSONN EL M- RESTRICTS 73SYSTEM PERFORMANCE

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.

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

Real time test bed development for power system operation, control and cyber security

NASA Astrophysics Data System (ADS)

Reddi, Ram Mohan

The operation and control of the power system in an efficient way is important in order to keep the system secure, reliable and economical. With advancements in smart grid, several new algorithms have been developed for improved operation and control. These algorithms need to be extensively tested and validated in real time before applying to the real electric power grid. This work focuses on the development of a real time test bed for testing and validating power system control algorithms, hardware devices and cyber security vulnerability. The test bed developed utilizes several hardware components including relays, phasor measurement units, phasor data concentrator, programmable logic controllers and several software tools. Current work also integrates historian for power system monitoring and data archiving. Finally, two different power system test cases are simulated to demonstrate the applications of developed test bed. The developed test bed can also be used for power system education.

Innovative Free-range Resonant Electrical Energy Delivery system (FREE-D System) for a ventricular assist device using wireless power.

PubMed

Waters, Benjamin H; Smith, Joshua R; Bonde, Pramod

2014-01-01

Technological innovation of a smaller, single moving part has an advantage over earlier large pulsatile ventricular assist devices (VADs) prone to mechanical failure. Drivelines limit the potential for extended patient survival durations with newer pumps and act as source for infection, increased morbidity, rehospitalizations, and reduced quality of life. The Free-range Resonant Electrical Energy Delivery (FREE-D) wireless power system uses magnetically coupled resonators to efficiently transfer power. We demonstrate the efficiency over distance of this system. The experimental setup consists of an radiofrequency amplifier and control board which drives the transmit resonator coil, and a receiver unit consisting of a resonant coil attached to a radiofrequency rectifier and power management module. The power management module supplies power to the axial pump, which was set at 9,600 rpm. To achieve a seamless wireless delivery in any room size, we introduced a third relay coil. This relay coil can be installed throughout a room, whereas a single relay coil could be built into a jacket worn by the patient, which would always be within range of the receive coil implanted in the patient's body. The power was delivered over a meter distance without interruptions or fluctuations with coil, rectifier, and regulator efficiency more than 80% and overall system efficiency of 61%. The axial pump worked well throughout the 8 hours of continuous operation. Having same setup on the opposite side can double the distance. A tether-free operation of a VAD can be achieved by FREE-D system in room-size distances. It has the potential to make the VAD therapy more acceptable from the patient perspective.

Adaptive Subframe Partitioning and Efficient Packet Scheduling in OFDMA Cellular System with Fixed Decode-and-Forward Relays

NASA Astrophysics Data System (ADS)

Wang, Liping; Ji, Yusheng; Liu, Fuqiang

The integration of multihop relays with orthogonal frequency-division multiple access (OFDMA) cellular infrastructures can meet the growing demands for better coverage and higher throughput. Resource allocation in the OFDMA two-hop relay system is more complex than that in the conventional single-hop OFDMA system. With time division between transmissions from the base station (BS) and those from relay stations (RSs), fixed partitioning of the BS subframe and RS subframes can not adapt to various traffic demands. Moreover, single-hop scheduling algorithms can not be used directly in the two-hop system. Therefore, we propose a semi-distributed algorithm called ASP to adjust the length of every subframe adaptively, and suggest two ways to extend single-hop scheduling algorithms into multihop scenarios: link-based and end-to-end approaches. Simulation results indicate that the ASP algorithm increases system utilization and fairness. The max carrier-to-interference ratio (Max C/I) and proportional fairness (PF) scheduling algorithms extended using the end-to-end approach obtain higher throughput than those using the link-based approach, but at the expense of more overhead for information exchange between the BS and RSs. The resource allocation scheme using ASP and end-to-end PF scheduling achieves a tradeoff between system throughput maximization and fairness.

Intelligent Load Manager (LOADMAN): Application of Expert System Technology to Load Management Problems in Power Generation and Distribution Systems

DTIC Science & Technology

1988-08-10

addrsesed to it, the wall-receptacle module energizes a relay. Modules can be built to use a triac instead and have the capacity to increase or decrease... modulated by other constraints for a safe, functional ana effective power distribution system. 2.2.3 BackuR Equipment Alternate power sources are...environments have limited sensor capability and no remote control capability. However, future enhancements to current equipment, such as frequency- modulated

Tracking and Data Relay Satellite System configuration and tradeoff study. Volume 4: Space shuttle launched TDRSS. Part 2: Final Report, 22 August 1972 - 1 April 1973

NASA Technical Reports Server (NTRS)

1973-01-01

Configuration data and design information for the space shuttle launched configuration is presented. The overall system definition, operations and control, and telecommunication service system including link budgets are discussed. A brief description of the user transceiver and ground station is presented. A final section includes a summary description of the TDR spacecraft and all the subsystems. The data presented are largely in tabular form.

Adaptive selective relaying in cooperative free-space optical systems over atmospheric turbulence and misalignment fading channels.

PubMed

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

2014-06-30

In this paper, a novel adaptive cooperative protocol with multiple relays using detect-and-forward (DF) over atmospheric turbulence channels with pointing errors is proposed. The adaptive DF cooperative protocol here analyzed is based on the selection of the optical path, source-destination or different source-relay links, with a greater value of fading gain or irradiance, maintaining a high diversity order. Closed-form asymptotic bit error-rate (BER) expressions are obtained for a cooperative free-space optical (FSO) communication system with Nr relays, when the irradiance of the transmitted optical beam is susceptible to either a wide range of turbulence conditions, following a gamma-gamma distribution of parameters α and β, or pointing errors, following a misalignment fading model where the effect of beam width, detector size and jitter variance is considered. A greater robustness for different link distances and pointing errors is corroborated by the obtained results if compared with similar cooperative schemes or equivalent multiple-input multiple-output (MIMO) systems. Simulation results are further demonstrated to confirm the accuracy and usefulness of the derived results.

Design of a high-numerical-aperture digital micromirror device camera with high dynamic range.

PubMed

Qiao, Yang; Xu, Xiping; Liu, Tao; Pan, Yue

2015-01-01

A high-NA imaging system with high dynamic range is presented based on a digital micromirror device (DMD). The DMD camera consists of an objective imaging system and a relay imaging system, connected by a DMD chip. With the introduction of a total internal reflection prism system, the objective imaging system is designed with a working F/# of 1.97, breaking through the F/2.45 limitation of conventional DMD projection lenses. As for the relay imaging system, an off-axis design that could correct off-axis aberrations of the tilt relay imaging system is developed. This structure has the advantage of increasing the NA of the imaging system while maintaining a compact size. Investigation revealed that the dynamic range of a DMD camera could be greatly increased, by 2.41 times. We built one prototype DMD camera with a working F/# of 1.23, and the field experiments proved the validity and reliability our work.

Preliminary Design Options for Meteor Burst Communications Systems Buoy Relays

DTIC Science & Technology

1986-12-01

FIELDS BRAYTON OTTO ELECTROSTATIC FIELDS SUPERCRITICAL Figure 5.1. Structure of current power source technology for ocean applications. 32 L / P 9 t ~A...As in the sulphur dioxide cell, a low weight, high surface area, carbon positive elec- trode acts as a catalyst for the reduction of the cathode...Operating Transmit Power No. (Relay/Service) Type Covert Covert Mode Duty Cycle (watts) 2.1 Trans Ocean Relay Shore/Ship No Yes Remote 20 Msg/hr 0.9

Thermal monitoring, measurement, and control system for a Volatile Condensable Materials (VCM) test apparatus

NASA Technical Reports Server (NTRS)

Ives, R. E.

1982-01-01

A thermal monitoring and control concept is described for a volatile condensable materials (VCM) test apparatus where electric resistance heaters are employed. The technique is computer based, but requires only proportioning ON/OFF relay control signals supplied through a programmable scanner and simple quadrac power controllers. System uniqueness is derived from automatic temperature measurements and the averaging of these measurements in discrete overlapping temperature zones. Overall control tolerance proves to be better than + or - 0.5 C from room ambient temperature to 150 C. Using precisely calibrated thermocouples, the method provides excellent temperature control of a small copper VCM heating plate at 125 + or - 0.2 C over a 24 hr test period. For purposes of unattended operation, the programmable computer/controller provides a continual data printout of system operation. Real time operator command is also provided for, as is automatic shutdown of the system and operator alarm in the event of malfunction.

Implementation of EPICS based vacuum control system for variable energy cyclotron centre, Kolkata

NASA Astrophysics Data System (ADS)

Roy, Anindya; Bhole, R. B.; Nandy, Partha P.; Yadav, R. C.; Pal, Sarbajit; Roy, Amitava

2015-03-01

The vacuum system of the Room Temperature (K = 130) Cyclotron of Variable Energy Cyclotron Centre is comprised of vacuum systems of main machine and Beam Transport System. The vacuum control system is upgraded to a PLC based Automated system from the initial relay based Manual system. The supervisory control of the vacuum system is implemented in Experimental Physics and Industrial Control System (EPICS). An EPICS embedded ARM based vacuum gauge controller is developed to mitigate the requirement of vendor specific gauge controller for gauges and also for seamless integration of the gauge controllers with the control system. A set of MS-Windows ActiveX components with embedded EPICS Channel Access interface are developed to build operator interfaces with less complex programming and to incorporate typical Windows feature, e.g., user authentication, file handling, better fonts, colors, mouse actions etc. into the operator interfaces. The control parameters, monitoring parameters, and system interlocks of the system are archived in MySQL based EPICS MySQL Archiver developed indigenously. In this paper, we describe the architecture, the implementation details, and the performance of the system.

Implementation of EPICS based vacuum control system for variable energy cyclotron centre, Kolkata.

PubMed

Roy, Anindya; Bhole, R B; Nandy, Partha P; Yadav, R C; Pal, Sarbajit; Roy, Amitava

2015-03-01

The vacuum system of the Room Temperature (K = 130) Cyclotron of Variable Energy Cyclotron Centre is comprised of vacuum systems of main machine and Beam Transport System. The vacuum control system is upgraded to a PLC based Automated system from the initial relay based Manual system. The supervisory control of the vacuum system is implemented in Experimental Physics and Industrial Control System (EPICS). An EPICS embedded ARM based vacuum gauge controller is developed to mitigate the requirement of vendor specific gauge controller for gauges and also for seamless integration of the gauge controllers with the control system. A set of MS-Windows ActiveX components with embedded EPICS Channel Access interface are developed to build operator interfaces with less complex programming and to incorporate typical Windows feature, e.g., user authentication, file handling, better fonts, colors, mouse actions etc. into the operator interfaces. The control parameters, monitoring parameters, and system interlocks of the system are archived in MySQL based EPICS MySQL Archiver developed indigenously. In this paper, we describe the architecture, the implementation details, and the performance of the system.

Multi-pair two-way massive MIMO AF relaying with ZFR/ZFT beamforming and imperfect CSI over ricean fading channels

NASA Astrophysics Data System (ADS)

Xu, Kui; Sun, Xiaoli; Zhang, Dongmei

2016-10-01

This paper investigates the spectral and energy efficiencies of a multi-pair two-way amplify-and-forward (AF) relay system over Ricean fading channels, where multiple user-pairs exchange information within pair through a relay with very large number of antennas, while each user equipped with a single antenna. Firstly, beamforming matrixe of zero-forcing reception/zero-forcing transmission (ZFR/ZFT) with imperfect channel state information (CSI) at the relay is given. Then, the unified asymptotic signal-to-interference-plus-noise ratio (SINR) expressions with imperfect CSI are obtained analytically. Finally, two power scaling schemes are proposed and the asymptotic spectral and energy efficiencies based on the proposed power scaling schemes are derived and verified by the Monte-Carlo simulations. Theoretical analyses and simulation results show that with imperfect CSI, if the number of relay antennas grows asymptotically large, we need cut down the transmit power of each user and relay to different proportion when the Ricean K-factor is non-zero and zero (Rayleigh fading) in order to maintain a desirable rate.

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.

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

3D head mount display with single panel

NASA Astrophysics Data System (ADS)

Wang, Yuchang; Huang, Junejei

2014-09-01

The head mount display for entertainment usually requires light weight. But in the professional application has more requirements. The image quality, field of view (FOV), color gamut, response and life time are considered items, too. A head mount display based on 1-chip TI DMD spatial light modulator is proposed. The multiple light sources and splitting images relay system are the major design tasks. The relay system images the object (DMD) into two image planes to crate binocular vision. The 0.65 inch 1080P DMD is adopted. The relay has a good performance which includes the doublet to reduce the chromatic aberration. Some spaces are reserved for placing the mirror and adjustable mechanism. The mirror splits the rays to the left and right image plane. These planes correspond to the eyepieces objects and image to eyes. A changeable mechanism provides the variable interpupillary distance (IPD). The folding optical path makes sure that the HMD center of gravity is close to the head and prevents the uncomfortable downward force being applied to head or orbit. Two RGB LED assemblies illuminate to the DMD in different angle. The light is highly collimated. The divergence angle is small enough such that one LED ray would only enters to the correct eyepiece. This switching is electronic controlled. There is no moving part to produce vibration and fast switch would be possible. Two LED synchronize with 3D video sync by a driving board which also controls the DMD. When the left eye image is displayed on DMD, the LED for left optical path turns on. Vice versa for right image and 3D scene is accomplished.

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).

[Communication subsystem design of tele-screening system for diabetic retinopathy].

PubMed

Chen, Jian; Pan, Lin; Zheng, Shaohua; Yu, Lun

2013-12-01

A design scheme of a tele-screening system for diabetic retinopathy (DR) has been proposed, especially the communication subsystem. The scheme uses serial communication module consisting of ARM 7 microcontroller and relays to connect remote computer and fundus camera, and also uses C++ programming language based on MFC to design the communication software consisting of therapy and diagnostic information module, video/audio surveillance module and fundus camera control module. The scheme possesses universal property in some remote medical treatment systems which are similar to the system.

Potential problems relative to TDRS/IUS tilt table elevation with failed VRCS

NASA Technical Reports Server (NTRS)

Bell, J.

1980-01-01

Operational concerns and preliminary solution alternatives related to elevating the inertial upper stage/tracking and data relay satellite (IUS/TDRS) with a failed orbiter vernier reaction control system (VRCS) are presented. Problems arise from the combination of TDRS thermal constraints and tilt table constraints (the primary reaction control system (PRCS) cannot be used to hold attitude while the tilt table is being elevated), and the problems are compounded by the minimum PRCS attitude deadband. The potential solution options are affected by the launch window, flight profile, crew procedures, vehicle capability and constraints, and flight rules.

Study of Increasing Lead Times in Major Weapon Systems Acquisition.

DTIC Science & Technology

1982-07-31

Conduit Covers X X X Connectors, Electrical X X X X X Control Systems (Auto- mated, Boiler) X Davit, Boat, Power- Opera.ted X Diodes X X X X A iX...tubes. Other end uses include washers in computer equipment, electrical insulators in motors and generators, and retardation plates in lasers . Supply...relays, electron tubes, printed circuits, and resistors. Platinum is also used in dentistry and for jewelry. Supply, A small amount of platinum (less

An Architectural Framework for Describing Supervisory Control and Data Acquisition (SCADA) Systems

DTIC Science & Technology

2004-09-01

having one of two possible values, described as 0 or 1. Boundary A logical segregation of related components in a system. The segregation may be based ...Depending on the sophistication of the microcontroller in the RTU, it can be configured to act as a relay station for other RTUs which cannot...communicate directly with a master station, or the microcontroller can communicate on a peer-to-peer basis with other RTUs. RTUs are generally remotely

Development of a Real-Time Hardware-in- the-Loop Power Systems Simulation Platform to Evaluate Commercial Microgrid Controllers

DTIC Science & Technology

2016-02-23

52 A.3 Solar irradiance profile. 53 xi LIST OF TABLES Table Page No. 1 Cable Impedances 14 2 PV Component Specifications 25 3 ESS...of the physical DER devices, including gensets, a battery-based energy storage system with a bidirectional power converter, a solar photovoltaic ( PV ...this was done for the energy storage, solar PV , and breakers.) Implement several relay protection functions to actuate the breakers. Implement various

MST's Programmable Power Supplies: Bt Update, Bp Prototype

NASA Astrophysics Data System (ADS)

Holly, D. J.; Chapman, B. E.; McCollam, K. J.; Morin, J. C.; Thomas, M. A.

2013-10-01

MST's toroidal field programmable power supply (Bt PPS) has now been in operation for several years and has provided important new capabilities. One of the primary goals for the Bt PPS is the partial optimization of inductive current profile control, involving control of the poloidal electric field. The Bt PPS has achieved fluctuation reduction over MST's entire range of Ip. At the largest Ip, the Bt PPS achieves fluctuation reduction with a smaller poloidal electric field than the previous passive system, implying that substantially longer periods of current profile control may be possible. The Bt PPS has also been used to produce Ohmic tokamak plasmas in MST. With an applied toroidal field of 0.135 T, and q(a) > 2, the estimated energy confinement time is roughly consistent with neo-Alcator scaling. Driving q(a) < 2 with larger Ip, the confinement time degrades, but the discharge duration does not terminate prematurely. To fully optimize current profile control and to test MST operational limits, a PPS is also needed for the Bp circuit. Currently in prototype stage, the Bp PPS will feature a number of innovations to increase its flexibility and performance. Isolated charging, control, and monitor systems will eliminate charging relays, reduce coupling between modules, and minimize capacitor heating. Seven-level pulse width modulation will reduce output ripple and switching losses. Solid state shorting bars will eliminate shorting relays and minimize wiring. A balanced switching algorithm will minimize capacitive noise generation. Work supported by U. S. D. o. E.

Multipath study for a low altitude satellite utilizing a data relay satellite system

NASA Technical Reports Server (NTRS)

Eggert, D.

1970-01-01

Technical considerations associated with a low altitude satellite operating in conjuction with a data relay satellite system are reported. Emphasis was placed on the quantitative characterization of multipath phenomenon and determination of power received via both the direct and earth reflection paths. Attempts were made to develop a means for estimating the magnitude and nature of the reflected power.

Analysis of Experimental Sea-level Transient Data and Analog Method of Obtaining Altitude Response for Turbine-propeller Engine with Relay-type Speed Control

NASA Technical Reports Server (NTRS)

Vasu, George; Pack, George J

1951-01-01

Correlation has been established between transient engine and control data obtained experimentally and data obtained by simulating the engine and control with an analog computer. This correlation was established at sea-level conditions for a turbine-propeller engine with a relay-type speed control. The behavior of the controlled engine at altitudes of 20,000 and 35,000 feet was determined with an analog computer using the altitude pressure and temperature generalization factors to calculate the new engine constants for these altitudes. Because the engine response varies considerably at altitude some type of compensation appears desirable and four methods of compensation are discussed.

Localization and cooperative communication methods for cognitive radio

NASA Astrophysics Data System (ADS)

Duval, Olivier

We study localization of nearby nodes and cooperative communication for cognitive radios. Cognitive radios sensing their environment to estimate the channel gain between nodes can cooperate and adapt their transmission power to maximize the capacity of the communication between two nodes. We study the end-to-end capacity of a cooperative relaying scheme using orthogonal frequency-division modulation (OFDM) modulation, under power constraints for both the base station and the relay station. The relay uses amplify-and-forward and decode-and-forward cooperative relaying techniques to retransmit messages on a subset of the available subcarriers. The power used in the base station and the relay station transmitters is allocated to maximize the overall system capacity. The subcarrier selection and power allocation are obtained based on convex optimization formulations and an iterative algorithm. Additionally, decode-and-forward relaying schemes are allowed to pair source and relayed subcarriers to increase further the capacity of the system. The proposed techniques outperforms non-selective relaying schemes over a range of relay power budgets. Cognitive radios can be used for opportunistic access of the radio spectrum by detecting spectrum holes left unused by licensed primary users. We introduce a spectrum holes detection approach, which combines blind modulation classification, angle of arrival estimation and number of sources detection. We perform eigenspace analysis to determine the number of sources, and estimate their angles of arrival (AOA). In addition, we classify detected sources as primary or secondary users with their distinct second-orde one-conjugate cyclostationarity features. Extensive simulations carried out indicate that the proposed system identifies and locates individual sources correctly, even at -4 dB signal-to-noise ratios (SNR). In environments with a high density of scatterers, several wireless channels experience nonline-of-sight (NLOS) condition, increasing the localization error, even when the AOA estimate is accurate. We present a real-time localization solver (RTLS) for time-of-arrival (TOA) estimates using ray-tracing methods on the map of the geometry of walls and compare its performance with classical TOA trilateration localization methods. Extensive simulations and field trials for indoor environments show that our method increases the coverage area from 1.9% of the floor to 82.3 % and the accuracy by a 10-fold factor when compared with trilateration. We implemented our ray tracing model in C++ using the CGAL computational geometry algorithm library. We illustrate the real-time property of our RTLS that performs most ray tracing tasks in a preprocessing phase with time and space complexity analyses and profiling of our software.

47 CFR 90.243 - Mobile relay stations.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND... Service. (b) Special provisions for mobile relay operations: (1) In the Public Safety Pool, systems operating on any of the public safety frequencies listed in § 90.20(c) are permitted to be cross-banded for...

Scheduling algorithm for data relay satellite optical communication based on artificial intelligent optimization

NASA Astrophysics Data System (ADS)

Zhao, Wei-hu; Zhao, Jing; Zhao, Shang-hong; Li, Yong-jun; Wang, Xiang; Dong, Yi; Dong, Chen

2013-08-01

Optical satellite communication with the advantages of broadband, large capacity and low power consuming broke the bottleneck of the traditional microwave satellite communication. The formation of the Space-based Information System with the technology of high performance optical inter-satellite communication and the realization of global seamless coverage and mobile terminal accessing are the necessary trend of the development of optical satellite communication. Considering the resources, missions and restraints of Data Relay Satellite Optical Communication System, a model of optical communication resources scheduling is established and a scheduling algorithm based on artificial intelligent optimization is put forwarded. According to the multi-relay-satellite, multi-user-satellite, multi-optical-antenna and multi-mission with several priority weights, the resources are scheduled reasonable by the operation: "Ascertain Current Mission Scheduling Time" and "Refresh Latter Mission Time-Window". The priority weight is considered as the parameter of the fitness function and the scheduling project is optimized by the Genetic Algorithm. The simulation scenarios including 3 relay satellites with 6 optical antennas, 12 user satellites and 30 missions, the simulation result reveals that the algorithm obtain satisfactory results in both efficiency and performance and resources scheduling model and the optimization algorithm are suitable in multi-relay-satellite, multi-user-satellite, and multi-optical-antenna recourses scheduling problem.

Enhancing Propriospinal Relays to Improve Functional Recovery after SCI

DTIC Science & Technology

2016-10-01

the motor cortex , locus coeruleus or vestibular nuclei. In general, the number of GFP labeled neurons within the red nucleus was approximately a...Introduction: Spinal cord injury causes life-long neurological impairment, with loss of sensory and motor function distal to the point of injury...major problems remain in achieving long distance regeneration of higher functioning motor control systems, such as the corticospinal tract, making

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.

Federation of UML models for cyber physical use cases

DOE Office of Scientific and Technical Information (OSTI.GOV)

This method employs the concept of federation, which is defined as the use of existing models that represent aspects of a system in specific domains (such as physical and cyber security domains) and building interfaces to link all of domain models. Federation seeks to build on existing bodies of work. Some examples include the Common Information Models (CIM) maintained by the International Electrotechnical Commission Technical Committee 57 (IEC TC 57) for the electric power industry. Another relevant model is the CIM maintained by the Distributed Management Task Force (DMTF)? this CIM defines a representation of the managed elements in anmore » Information Technology (IT) environment. The power system is an example of a cyber-physical system, where the cyber systems, consisting of computing infrastructure such as networks and devices, play a critical role in the operation of the underlying physical electricity delivery system. Measurements from remote field devices are relayed to control centers through computer networks, and the data is processed to determine suitable control actions. Control decisions are then relayed back to field devices. It has been observed that threat actors may be able to successfully compromise this cyber layer in order to impact power system operation. Therefore, future control center applications must be wary of potentially compromised measurements coming from field devices. In order to ensure the integrity of the field measurements, these applications could make use of compromise indicators from alternate sources of information such as cyber security. Thus, modern control applications may require access to data from sources that are not defined in the local information model. In such cases, software application interfaces will require integration of data objects from cross-domain data models. When incorporating or federating different domains, it is important to have subject matter experts work together, recognizing that not everyone has the same knowledge, responsibilities, focus, or skill set.« less

Process computerization of No. 13 blast furnace at Gary works

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sherman, G.J.; Zmierski, M.L.; Hyle, F.W.

1993-10-01

No. 13 blast furnace underwent extensive modifications to the process control system during the second reline. This represents a major shift in control philosophy from hardwired relays and analog controllers to a totally integrated computer control system. The new system created the opportunity for comprehensive diagnostic analysis and increased flexibility for control strategy modifications. The goal of achieving maximum production with minimal delay was accomplished by an integrated test, and comprehensive operator and maintenance training. Normal production was reached within four days of blow-ink and design production capacity of 7800 NTHM/day was met in the third month of operation. Recordmore » furnace productivity of 8931 NTHM/day (8.56 NTHM/100 crwv) was achieved in less than five months of operation and again in April 1992 of 9062 NTHM/day (8.68 NTHM/100 cfwv).« less

Development of the European Small Geostationary Satellite SGEO

NASA Astrophysics Data System (ADS)

Lübberstedt, H.; Schneider, A.; Schuff, H.; Miesner, Th.; Winkler, A.

2008-08-01

The SGEO product portfolio, ranging from Satellite platform delivery up to in-orbit delivery of a turnkey system including satellite and ground control station, is designed for applications ranging from TV Broadcast to multimedia applications, Internet access, mobile or fixed services in a wide range of frequency bands. Furthermore, Data Relay missions such as the European Data Relay Satellite (EDRS) as well as other institutional missions are targeted. Key design features of the SGEO platform are high flexibility and modularity in order to accommodate a very wide range of future missions, a short development time below two years and the objective to build the system based on ITAR free subsystems and components. The system will provide a long lifetime of up to 15 years in orbit operations with high reliability. SGEO is the first European satellite to perform all orbit control tasks solely by electrical propulsion (EP). This design provides high mass efficiency and the capability for direct injection into geostationary orbit without chemical propulsion (CP). Optionally, an Apogee Engine Module based on CP will provide the perigee raising manoeuvres in case of a launch into geostationary transfer orbit (GTO). This approach allows an ideal choice out of a wide range of launcher candidates in dependence of the required payload capacity. SGEO will offer to the market a versatile and high performance satellite system with low investment risk for the customer and a short development time. This paper provides an overview of the SGEO system key features and the current status of the SGEO programme.

DOE Office of Scientific and Technical Information (OSTI.GOV)

J. E. Lawson, R. Marsala, S. Ramakrishnan, X. Zhao, P. Sichta

In order to provide improved and expanded experimental capabilities, the existing Transrex power supplies at PPPL are to be upgraded and modernized. Each of the 39 power supplies consists of two six pulse silicon controlled rectifier sections forming a twelve pulse power supply. The first modification is to split each supply into two independent six pulse supplies by replacing the existing obsolete twelve pulse firing generator with two commercially available six pulse firing generators. The second change replaces the existing control link with a faster system, with greater capacity, which will allow for independent control of all 78 power supplymore » sections. The third change replaces the existing Computer Automated Measurement and Control (CAMAC) based fault detector with an Experimental Physics and Industrial Control System (EPICS) compatible unit, eliminating the obsolete CAMAC modules. Finally the remaining relay logic and interfaces to the "Hardwired Control System" will be replaces with a Programmable Logic Controller (PLC).« less

Topological Interference Management for K-User Downlink Massive MIMO Relay Network Channel.

PubMed

Selvaprabhu, Poongundran; Chinnadurai, Sunil; Li, Jun; Lee, Moon Ho

2017-08-17

In this paper, we study the emergence of topological interference alignment and the characterizing features of a multi-user broadcast interference relay channel. We propose an alternative transmission strategy named the relay space-time interference alignment (R-STIA) technique, in which a K -user multiple-input-multiple-output (MIMO) interference channel has massive antennas at the transmitter and relay. Severe interference from unknown transmitters affects the downlink relay network channel and degrades the system performance. An additional (unintended) receiver is introduced in the proposed R-STIA technique to overcome the above problem, since it has the ability to decode the desired signals for the intended receiver by considering cooperation between the receivers. The additional receiver also helps in recovering and reconstructing the interference signals with limited channel state information at the relay (CSIR). The Alamouti space-time transmission technique and minimum mean square error (MMSE) linear precoder are also used in the proposed scheme to detect the presence of interference signals. Numerical results show that the proposed R-STIA technique achieves a better performance in terms of the bit error rate (BER) and sum-rate compared to the existing broadcast channel schemes.

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.

Topological Interference Management for K-User Downlink Massive MIMO Relay Network Channel

PubMed Central

Li, Jun; Lee, Moon Ho

2017-01-01

In this paper, we study the emergence of topological interference alignment and the characterizing features of a multi-user broadcast interference relay channel. We propose an alternative transmission strategy named the relay space-time interference alignment (R-STIA) technique, in which a K-user multiple-input-multiple-output (MIMO) interference channel has massive antennas at the transmitter and relay. Severe interference from unknown transmitters affects the downlink relay network channel and degrades the system performance. An additional (unintended) receiver is introduced in the proposed R-STIA technique to overcome the above problem, since it has the ability to decode the desired signals for the intended receiver by considering cooperation between the receivers. The additional receiver also helps in recovering and reconstructing the interference signals with limited channel state information at the relay (CSIR). The Alamouti space-time transmission technique and minimum mean square error (MMSE) linear precoder are also used in the proposed scheme to detect the presence of interference signals. Numerical results show that the proposed R-STIA technique achieves a better performance in terms of the bit error rate (BER) and sum-rate compared to the existing broadcast channel schemes. PMID:28817071

Apollo Soyuz test project press kit: USA-USSR

NASA Technical Reports Server (NTRS)

1975-01-01

The goals and program of the mission are described. Operations from preflight crew training through splashdown are included. Spacecraft and launch vehicle configurations are given. The 27 joint and unilateral experiments to be performed are described. A flight plan and a schedule of activities is included, together with brief crew biographies. The ground support system is discussed; it includes control centers in Houston and Moscow, and an ATS satellite to relay ground-air-ground communications. The global tracking network and the television transmission system are also described.

FIESTA: An operational decision aid for space network fault isolation

NASA Technical Reports Server (NTRS)

Lowe, Dawn; Quillin, Bob; Matteson, Nadine; Wilkinson, Bill; Miksell, Steve

1987-01-01

The Fault Tolerance Expert System for Tracking and Data Relay Satellite System (TDRSS) Applications (FIESTA) is a fault detection and fault diagnosis expert system being developed as a decision aid to support operations in the Network Control Center (NCC) for NASA's Space Network. The operational objectives which influenced FIESTA development are presented and an overview of the architecture used to achieve these goals are provided. The approach to the knowledge engineering effort and the methodology employed are also presented and illustrated with examples drawn from the FIESTA domain.

Tracking and Data Relay Satellite System configuration and tradeoff study. Volume 3: Atlas Centaur launched TDRSS. Part 2: Final Report, 22 August 1972 - 1 April 1973

NASA Technical Reports Server (NTRS)

1973-01-01

Configuration data and design information for the Atlas Centaur launched configuration are presented. Overall system definition, operations and control, and telecommunication service system, including link budgets, are discussed. A brief description of the user telecommunications equipment and ground station is presented. A summary description of the TDR spacecraft and all the subsystems is included. The data presented are largely in tabular form. A brief treatment of an optional configuration with enhanced telecommunications service is described.

HIGH SPEED KERR CELL FRAMING CAMERA

DOEpatents

Goss, W.C.; Gilley, L.F.

1964-01-01

The present invention relates to a high speed camera utilizing a Kerr cell shutter and a novel optical delay system having no moving parts. The camera can selectively photograph at least 6 frames within 9 x 10/sup -8/ seconds during any such time interval of an occurring event. The invention utilizes particularly an optical system which views and transmits 6 images of an event to a multi-channeled optical delay relay system. The delay relay system has optical paths of successively increased length in whole multiples of the first channel optical path length, into which optical paths the 6 images are transmitted. The successively delayed images are accepted from the exit of the delay relay system by an optical image focusing means, which in turn directs the images into a Kerr cell shutter disposed to intercept the image paths. A camera is disposed to simultaneously view and record the 6 images during a single exposure of the Kerr cell shutter. (AEC)

Design of a novel Hyper-spectral riflescope system

NASA Astrophysics Data System (ADS)

Huang, YunHan; Fu, YueGang

2016-10-01

Hyper-spectral imaging involves many research areas, such as optics, spectroscopy, mechanical, microelectronics, and computers, etc. Hyper-spectral imaging system has an irreplaceable role in the detection field. At present, due to the improvement of camouflage technology, characteristic of target in battlefield becomes more complex and the targets became more and more difficult to be detected, According to this phenomenon the author designed a novel hyper-spectral riflescope optical system. In general, the riflescope optical system is composed of two parts front object lens and zoom relay system. Firstly, dispersion characteristics of the typical optical glasses varies during band 400nm 1 000nm, the author derived apochromatic theory that suitable to the front system and relay system without using special glass, and make a example to testify its correctness. In general, the zoom mode of relay system lens is different from the objective lens system, so we should take consideration of them separately. Secondly, based on the above theory, the articles designed a hyper-spectral riflescope system, which has a continuous zoom curve, zoom ratio is 4 times and the F number of the system is 4.8;Full field of view varies during 1.8° 7.2°.Structure of the system is relatively compact, and has not used special glass, eventually the article give the schematic of system MTF and zoom curves of relay movable parts. the curve is smooth and can be applied to practical engineering. The author adopt ZEMAX design software to analyses the results .Design result shows that, in the visible and near-infrared wavelengths, the MTF of imaging system at 60lp / mm during all bands are greater than 0.3, which prove the correctness of the design theory and good performance of system.

KSC-2013-4396

NASA Image and Video Library

2013-12-12

CAPE CANAVERAL, Fla. – The United Launch Alliance Atlas V first stage booster that will boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft into orbit arrives at Cape Canaveral Air Force Station's Launch Complex 41. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/Kim Shiflett

KSC-2013-4394

NASA Image and Video Library

2013-12-12

CAPE CANAVERAL, Fla. – The United Launch Alliance Atlas V first stage booster that will boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft into orbit arrives at Cape Canaveral Air Force Station's Launch Complex 41. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/Kim Shiflett

KSC-2013-4428

NASA Image and Video Library

2013-12-13

CAPE CANAVERAL, Fla. – At Cape Canaveral Air Force Station's Launch Complex 41, a Centaur second stage is positioned atop a United Launch Alliance Atlas V rocket that will be used to boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft to orbit. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/Charisse Nahser

KSC-2013-3790

NASA Image and Video Library

2013-11-01

CAPE CANAVERAL, Fla. – The United Launch Alliance Centaur upper stage that will boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft into orbit arrives at the Atlas Spaceflight Operations Center on Cape Canaveral Air Force Station for checkout in preparation for launch. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/ Jim Grossman

KSC-2013-4395

NASA Image and Video Library

2013-12-12

CAPE CANAVERAL, Fla. – The United Launch Alliance Atlas V first stage booster that will boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft into orbit arrives at Cape Canaveral Air Force Station's Launch Complex 41. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/Kim Shiflett

KSC-2013-3792

NASA Image and Video Library

2013-11-01

CAPE CANAVERAL, Fla. – The United Launch Alliance Centaur upper stage that will boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft into orbit arrives at the Atlas Spaceflight Operations Center on Cape Canaveral Air Force Station for checkout in preparation for launch. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/ Jim Grossman

KSC-2013-4429

NASA Image and Video Library

2013-12-13

CAPE CANAVERAL, Fla. – At Cape Canaveral Air Force Station's Launch Complex 41, a Centaur second stage is positioned atop a United Launch Alliance Atlas V rocket that will be used to boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft to orbit. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/Charisse Nahser

Measurement-Device-Independent Quantum Key Distribution over Untrustful Metropolitan Network

NASA Astrophysics Data System (ADS)

Tang, Yan-Lin; Yin, Hua-Lei; Zhao, Qi; Liu, Hui; Sun, Xiang-Xiang; Huang, Ming-Qi; Zhang, Wei-Jun; Chen, Si-Jing; Zhang, Lu; You, Li-Xing; Wang, Zhen; Liu, Yang; Lu, Chao-Yang; Jiang, Xiao; Ma, Xiongfeng; Zhang, Qiang; Chen, Teng-Yun; Pan, Jian-Wei

2016-01-01

Quantum cryptography holds the promise to establish an information-theoretically secure global network. All field tests of metropolitan-scale quantum networks to date are based on trusted relays. The security critically relies on the accountability of the trusted relays, which will break down if the relay is dishonest or compromised. Here, we construct a measurement-device-independent quantum key distribution (MDIQKD) network in a star topology over a 200-square-kilometer metropolitan area, which is secure against untrustful relays and against all detection attacks. In the field test, our system continuously runs through one week with a secure key rate 10 times larger than previous results. Our results demonstrate that the MDIQKD network, combining the best of both worlds—security and practicality, constitutes an appealing solution to secure metropolitan communications.

Computer Controlled Portable Greenhouse Climate Control System for Enhanced Energy Efficiency

NASA Astrophysics Data System (ADS)

Datsenko, Anthony; Myer, Steve; Petties, Albert; Hustek, Ryan; Thompson, Mark

2010-04-01

This paper discusses a student project at Kettering University focusing on the design and construction of an energy efficient greenhouse climate control system. In order to maintain acceptable temperatures and stabilize temperature fluctuations in a portable plastic greenhouse economically, a computer controlled climate control system was developed to capture and store thermal energy incident on the structure during daylight periods and release the stored thermal energy during dark periods. The thermal storage mass for the greenhouse system consisted of a water filled base unit. The heat exchanger consisted of a system of PVC tubing. The control system used a programmable LabView computer interface to meet functional specifications that minimized temperature fluctuations and recorded data during operation. The greenhouse was a portable sized unit with a 5' x 5' footprint. Control input sensors were temperature, water level, and humidity sensors and output control devices were fan actuating relays and water fill solenoid valves. A Graphical User Interface was developed to monitor the system, set control parameters, and to provide programmable data recording times and intervals.

MOORE: A prototype expert system for diagnosing spacecraft problems

NASA Technical Reports Server (NTRS)

Howlin, Katherine; Weissert, Jerry; Krantz, Kerry

1988-01-01

MOORE is a rule-based, prototype expert system that assists in diagnosing operational Tracking and Data Relay Satellite (TDRS) problems. It is intended to assist spacecraft engineers at the TDRS ground terminal in trouble shooting problems that are not readily solved with routine procedures, and without expert counsel. An additional goal of the prototype system is to develop in-house expert system and knowledge engineering skills. The prototype system diagnoses antenna pointing and earth pointing problems that may occur within the TDRS Attitude Control System (ACS). Plans include expansion to fault isolation of problems in the most critical subsystems of the TDRS spacecraft. Long term benefits are anticipated with use of an expert system during future TDRS programs with increased mission support time, reduced problem solving time, and retained expert knowledge and experience. Phase 2 of the project is intended to provide NASA the necessary expertise and capability to define requirements, evaluate proposals, and monitor the development progress of a highly competent expert system for NASA's Tracking Data Relay Satellite. Phase 2 also envisions addressing two unexplored applications for expert systems, spacecraft integration and tests (I and T) and support to launch activities. The concept, goals, domain, tools, knowledge acquisition, developmental approach, and design of the expert system. It will explain how NASA obtained the knowledge and capability to develop the system in-house without assistance from outside consultants. Future plans will also be presented.

Data relay system specifications for ERTS image interpretation

NASA Technical Reports Server (NTRS)

Daniel, J. F.

1970-01-01

Experiments with the Data Collection System (DCS) of the Earth Resources Technology Satellites (ERTS) have been developed to stress ERTS applications in the Earth Resources Observation Systems (EROS) Program. Active pursuit of this policy has resulted in the design of eight specific experiments requiring a total of 98 DCS ground-data platforms. Of these eight experiments, six are intended to make use of DCS data as an aid in image interpretation, while two make use of the capability to relay data from remote locations. Preliminary discussions regarding additional experiments indicate a need for at least 150 DCS platforms within the EROS Program for ERTS experimentation. Results from the experiments will be used to assess the DCS suitability for satellites providing on-line, real-time, data relay capability. The rationale of the total DCS network of ground platforms and the relationship of each experiment to that rationale are discussed.

Implementation of EPICS based vacuum control system for variable energy cyclotron centre, Kolkata

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roy, Anindya, E-mail: r-ani@vecc.gov.in; Bhole, R. B.; Nandy, Partha P.

2015-03-15

The vacuum system of the Room Temperature (K = 130) Cyclotron of Variable Energy Cyclotron Centre is comprised of vacuum systems of main machine and Beam Transport System. The vacuum control system is upgraded to a PLC based Automated system from the initial relay based Manual system. The supervisory control of the vacuum system is implemented in Experimental Physics and Industrial Control System (EPICS). An EPICS embedded ARM based vacuum gauge controller is developed to mitigate the requirement of vendor specific gauge controller for gauges and also for seamless integration of the gauge controllers with the control system. A setmore » of MS-Windows ActiveX components with embedded EPICS Channel Access interface are developed to build operator interfaces with less complex programming and to incorporate typical Windows feature, e.g., user authentication, file handling, better fonts, colors, mouse actions etc. into the operator interfaces. The control parameters, monitoring parameters, and system interlocks of the system are archived in MySQL based EPICS MySQL Archiver developed indigenously. In this paper, we describe the architecture, the implementation details, and the performance of the system.« less

Remote-area health care delivery through space technology - STARPAHC

NASA Technical Reports Server (NTRS)

Belasco, N.; Johnston, R. S.; Stonesifer, J. C.; Pool, S. L.

1977-01-01

A joint NASA/HEW project called Space Technology Applied to Rural Papage Advanced Health Care (STARPAHC) has been developed to deliver quality health care to inhabitants of remote geographical areas. The system consists of a hospital-based support control center, a fixed clinic, a mobile clinic, and a referral center with access to specialists via television links to the control center. A strategically located relay station routes television, voice, and data transmissions between system elements. A model system has been installed on the Papage Indian Reservation in Arizona, and is undergoing a 2-year evaluation. The system has been shown to be both effective and cost-efficient, and applications of the concept are planned for future manned spacecraft flights.

Low noise charge ramp electrometer

DOEpatents

Morgan, John P.; Piper, Thomas C.

1992-01-01

An electrometer capable of measuring small currents without the use of a feedback resistor which tends to contribute a large noise factor to the measured data. The electrometer eliminates the feedback resistor through the use of a feedback capacitor located across the electrometer amplifier. The signal from the electrometer amplifier is transferred to a electrometer buffer amplifier which serves to transfer the signal to several receptors. If the electrometer amplifier is approaching saturation, the buffer amplifier signals a reset discriminator which energizes a coil whose magnetic field closes a magnetic relay switch which in turn resets or zeros the feedback capacitor. In turn, a reset complete discriminator restarts the measurement process when the electrometer amplifier approaches its initial condition. The buffer amplifier also transmits the voltage signal from the electrometer amplifier to a voltage-to-frequency converter. The signals from the voltage-to-frequency converter are counted over a fixed period of time and the information is relayed to a data processor. The timing and sequencing of the small current measuring system is under the control of a sequence control logic unit.

Low noise charge ramp electrometer

DOEpatents

Morgan, J.P.; Piper, T.C.

1992-10-06

An electrometer capable of measuring small currents without the use of a feedback resistor which tends to contribute a large noise factor to the measured data. The electrometer eliminates the feedback resistor through the use of a feedback capacitor located across the electrometer amplifier. The signal from the electrometer amplifier is transferred to a electrometer buffer amplifier which serves to transfer the signal to several receptors. If the electrometer amplifier is approaching saturation, the buffer amplifier signals a reset discriminator which energizes a coil whose magnetic field closes a magnetic relay switch which in turn resets or zeros the feedback capacitor. In turn, a reset complete discriminator restarts the measurement process when the electrometer amplifier approaches its initial condition. The buffer amplifier also transmits the voltage signal from the electrometer amplifier to a voltage-to-frequency converter. The signals from the voltage-to-frequency converter are counted over a fixed period of time and the information is relayed to a data processor. The timing and sequencing of the small current measuring system is under the control of a sequence control logic unit. 2 figs.

Power Allocation and Outage Probability Analysis for SDN-based Radio Access Networks

NASA Astrophysics Data System (ADS)

Zhao, Yongxu; Chen, Yueyun; Mai, Zhiyuan

2018-01-01

In this paper, performance of Access network Architecture based SDN (Software Defined Network) is analyzed with respect to the power allocation issue. A power allocation scheme PSO-PA (Particle Swarm Optimization-power allocation) algorithm is proposed, the proposed scheme is subjected to constant total power with the objective of minimizing system outage probability. The entire access network resource configuration is controlled by the SDN controller, then it sends the optimized power distribution factor to the base station source node (SN) and the relay node (RN). Simulation results show that the proposed scheme reduces the system outage probability at a low complexity.

Spacelab data management subsystem phase B study

NASA Technical Reports Server (NTRS)

1974-01-01

The Spacelab data management system is described. The data management subsystem (DMS) integrates the avionics equipment into an operational system by providing the computations, logic, signal flow, and interfaces needed to effectively command, control, monitor, and check out the experiment and subsystem hardware. Also, the DMS collects/retrieves experiment data and other information by recording and by command of the data relay link to ground. The major elements of the DMS are the computer subsystem, data acquisition and distribution subsystem, controls and display subsystem, onboard checkout subsystem, and software. The results of the DMS portion of the Spacelab Phase B Concept Definition Study are analyzed.

Highly sensitive vacuum ion pump current measurement system

DOEpatents

Hansknecht, John Christopher [Williamsburg, VA

2006-02-21

A vacuum system comprising: 1) an ion pump; 2) power supply; 3) a high voltage DC--DC converter drawing power from the power supply and powering the vacuum pump; 4) a feedback network comprising an ammeter circuit including an operational amplifier and a series of relay controlled scaling resistors of different resistance for detecting circuit feedback; 5) an optional power block section intermediate the power supply and the high voltage DC--DC converter; and 6) a microprocessor receiving feedback information from the feedback network, controlling which of the scaling resistors should be in the circuit and manipulating data from the feedback network to provide accurate vacuum measurement to an operator.

77 FR 16435 - Transmission Relay Loadability Reliability Standard

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-21

... are designed to read electrical measurements, such as current, voltage, and frequency, and can be set... an element of the system under its protection, it sends a signal to an interrupting device(s) (such... their relays according to one of thirteen specific settings (sub-parts R1.1 through R1.13) designed to...

76 FR 28 - Airworthiness Directives; The Boeing Company Model 757 Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-03

... relays having a ground fault interrupt (GFI) feature. That NPRM was prompted by results from fuel system..., -200CB, and -300 series airplanes. That NPRM was published in the Federal Register on October 19, 2009... pumps and override pumps with new relays having a ground fault interrupt (GFI) feature. Actions Since...

Confronting Cyberterrorism with Cyber Deception

DTIC Science & Technology

2003-12-01

break into computer systems. A further development in social engineering is the use of online translators and 41 relay telephony services that...allow social engineers to exploit and overcome language barriers [Ollmann, 2003]. Relay telephony services are online services provided by...open source media or actively seeking the information through unscrupulous means. - Desk checking - Social engineering - Dumpster diving

78 FR 78998 - 60-Day Notice of Proposed Information Collection: HUD Environmental Review Online System (HEROS)

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-27

...-free Federal Relay Service at (800) 877-8339. FOR FURTHER INFORMATION CONTACT: Danielle Schopp...-free Federal Information Relay Service at 1-800-877-8339. Copies of available documents submitted to... in most cases. 24 CFR Part 50, ``Protection and Enhancement of Environmental Quality,'' implements...

Teleoperated control system for underground room and pillar mining

DOEpatents

Mayercheck, William D.; Kwitowski, August J.; Brautigam, Albert L.; Mueller, Brian K.

1992-01-01

A teleoperated mining system is provided for remotely controlling the various machines involved with thin seam mining. A thin seam continuous miner located at a mining face includes a camera mounted thereon and a slave computer for controlling the miner and the camera. A plurality of sensors for relaying information about the miner and the face to the slave computer. A slave computer controlled ventilation sub-system which removes combustible material from the mining face. A haulage sub-system removes material mined by the continuous miner from the mining face to a collection site and is also controlled by the slave computer. A base station, which controls the supply of power and water to the continuous miner, haulage system, and ventilation systems, includes cable/hose handling module for winding or unwinding cables/hoses connected to the miner, an operator control module, and a hydraulic power and air compressor module for supplying air to the miner. An operator controlled host computer housed in the operator control module is connected to the slave computer via a two wire communications line.

Position control of an industrial robot using fractional order controller

NASA Astrophysics Data System (ADS)

Clitan, Iulia; Muresan, Vlad; Abrudean, Mihail; Clitan, Andrei; Miron, Radu

2017-02-01

This paper presents the design of a control structure that ensures no overshoot for the movement of an industrial robot, used for the evacuation of round steel blocks from inside a rotary hearth furnace. First, a mathematical model for the positioning system is derived from a set of experimental data, and further, the paper focuses on obtaining a PID type controller, using the relay method as tuning method in order to obtain a stable closed loop system. The controller parameters are further tuned in order to achieve the imposed set of performances for the positioning of the industrial robot through computer simulation, using trial and error method. Further, a fractional - order PID controller is obtained in order to improve the control signal variation, so as to fit within the range of unified current's variation, 4 to 20 mA.

Performance, operational limits, of an Electronic Switching Spherical Array (ESSA) antenna

NASA Technical Reports Server (NTRS)

Stockton, R.

1979-01-01

The development of a microprocessor controller which provides multimode operational capability for the Electronic Switching Spherical Array (ESSA) Antenna is described. The best set of operating conditions were determined and the performance of an ESSA antenna was demonstrated in the following modes: (1) omni; (2) acquisition/track; (3) directive; and (4) multibeam. The control algorithms, software flow diagrams, and electronic circuitry were developed. The microprocessor and control electronics were built and interfaced with the antenna to carry out performance testing. The acquisition/track mode for users in the Tracking and Data Relay Satellite System is emphasized.

Integrated Power/Attitude Control System (IPACS) study. Volume 1: Feasibility studies. [application of flywheels for power storage and generation

NASA Technical Reports Server (NTRS)

Notti, J. E.; Cormack, A., III; Schmill, W. C.

1974-01-01

An Integrated Power/Attitude Control System (IPACS) concept consisting of an array of spinning flywheels, with or without gimbals, capable of performing the dual function of power storage and generation, as well as attitude control has been investigated. This system provides attitude control through momentum storage, and replaces the storage batteries onboard the spacecraft. The results of the investigation are presented in two volumes. The trade-off studies performed to establish the feasibility, cost effectiveness, required level of development, and boundaries of application of IPACS to a wide variety of spacecraft are discussed. The conceptual designs for a free-flying research application module (RAM), and for a tracking and data relay satellite (TDRS) are presented. Results from dynamic analyses and simulations of the IPACS conceptual designs are included.

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

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.

Ground Simulation of an Autonomous Satellite Rendezvous and Tracking System Using Dual Robotic Systems

NASA Technical Reports Server (NTRS)

Trube, Matthew J.; Hyslop, Andrew M.; Carignan, Craig R.; Easley, Joseph W.

2012-01-01

A hardware-in-the-loop ground system was developed for simulating a robotic servicer spacecraft tracking a target satellite at short range. A relative navigation sensor package "Argon" is mounted on the end-effector of a Fanuc 430 manipulator, which functions as the base platform of the robotic spacecraft servicer. Machine vision algorithms estimate the pose of the target spacecraft, mounted on a Rotopod R-2000 platform, relay the solution to a simulation of the servicer spacecraft running in "Freespace", which performs guidance, navigation and control functions, integrates dynamics, and issues motion commands to a Fanuc platform controller so that it tracks the simulated servicer spacecraft. Results will be reviewed for several satellite motion scenarios at different ranges. Key words: robotics, satellite, servicing, guidance, navigation, tracking, control, docking.

Application of Hybrid Real-Time Power System Simulator for Designing and Researching of Relay Protection and Automation

NASA Astrophysics Data System (ADS)

Borovikov, Yu S.; Sulaymanov, A. O.; Andreev, M. V.

2015-10-01

Development, research and operation of smart grids (SG) with active-adaptive networks (AAS) are actual tasks for today. Planned integration of high-speed FACTS devices greatly complicates complex dynamic properties of power systems. As a result the operating conditions of equipment of power systems are significantly changing. Such situation creates the new actual problem of development and research of relay protection and automation (RPA) which will be able to adequately operate in the SGs and adapt to its regimes. Effectiveness of solution of the problem depends on using tools - different simulators of electric power systems. Analysis of the most famous and widely exploited simulators led to the conclusion about the impossibility of using them for solution of the mentioned problem. In Tomsk Polytechnic University developed the prototype of hybrid multiprocessor software and hardware system - Hybrid Real-Time Power System Simulator (HRTSim). Because of its unique features this simulator can be used for solution of mentioned tasks. This article introduces the concept of development and research of relay protection and automation with usage of HRTSim.

Inexpensive automated paging system for use at remote research sites

USGS Publications Warehouse

Sargent, S.L.; Dey, W.S.; Keefer, D.A.

1998-01-01

The use of a flow-activated automatic sampler at a remote research site required personnel to periodically visit the site to collect samples and reset the automatic sampler. To reduce site visits, a cellular telephone was modified for activation by a datalogger. The purpose of this study was to demonstrate the use and benefit of the modified telephone. Both the power switch and the speed-dial button on the telephone were bypassed and wired to a relay driver. The datalogger was programmed to compare values of a monitored environmental parameter with a target value. When the target value was reached or exceeded, the datalogger pulsed a relay driver, activating power to the telephone. A separate relay activated the speed dial, dialing the number of a tone-only pager. The use of this system has saved time and reduced travel costs by reducing the number of trips to the site, without the loss of any data.The use of a flow-activated automatic sampler at a remote research site required personnel to periodically visit the site to collect samples and reset the automatic sampler. To reduce site visits, a cellular telephone was modified for activation by a datalogger. The purpose of this study was to demonstrate the use and benefit of the modified telephone. Both the power switch and the speed-dial button on the telephone were bypassed and wired to a relay driver. The datalogger was programmed to compare values of a monitored environmental parameter with a target value. When the target value was reached or exceeded, the datalogger pulsed a relay driver, activating power to the telephone. A separate relay activated the speed dial, dialing the number of a tone-only pager. The use of this system has saved time and reduced travel costs by reducing the number of trips to the site, without the loss of any data.

KSC-2013-4406

NASA Image and Video Library

2013-12-13

CAPE CANAVERAL, Fla. – At Cape Canaveral Air Force Station, the first stage of the United Launch Alliance Atlas V rocket is lifted for stacking in the Vertical Integration Facility at Launch Complex 41. The vehicle will be used to boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft to orbit. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/Charisse Nahser

KSC-2013-4431

NASA Image and Video Library

2013-12-13

CAPE CANAVERAL, Fla. – At Cape Canaveral Air Force Station's Launch Complex 41, a United Launch Alliance Atlas V rocket, with its Centaur second stage atop, stands in the Vertical Integration Facility as preparations continue for lift off of the Tracking and Data Relay Satellite, or TDRS-L. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/Charisse Nahser

KSC-2013-4407

NASA Image and Video Library

2013-12-13

CAPE CANAVERAL, Fla. – At Cape Canaveral Air Force Station, the first stage of the United Launch Alliance Atlas V rocket is lifted for stacking in the Vertical Integration Facility at Launch Complex 41. The vehicle will be used to boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft to orbit. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/Charisse Nahser

KSC-2013-4415

NASA Image and Video Library

2013-12-13

CAPE CANAVERAL, Fla. – At Cape Canaveral Air Force Station, the first stage of the United Launch Alliance Atlas V rocket positioned in the Vertical Integration Facility at Launch Complex 41. The vehicle will be used to boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft to orbit. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/Charisse Nahser

KSC-2013-4418

NASA Image and Video Library

2013-12-13

CAPE CANAVERAL, Fla. – The United Launch Alliance Centaur second stage that will help boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft into orbit is being transported from the hangar at the Atlas Spaceflight Operations Center on Cape Canaveral Air Force Station to Launch Complex 41. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/Charisse Nahser

KSC-2013-4421

NASA Image and Video Library

2013-12-13

CAPE CANAVERAL, Fla. – At Cape Canaveral Air Force Station's Launch Complex 41, a technician supports preparations for lifting the Centaur second stage of the United Launch Alliance rocket that will be used to boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft to orbit. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/Charisse Nahser

KSC-2013-4427

NASA Image and Video Library

2013-12-13

CAPE CANAVERAL, Fla. – At Cape Canaveral Air Force Station's Launch Complex 41, a Centaur second stage is lifted for stacking atop a United Launch Alliance Atlas V rocket that will be used to boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft to orbit. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/Charisse Nahser

KSC-2013-3791

NASA Image and Video Library

2013-11-01

CAPE CANAVERAL, Fla. – The United Launch Alliance Atlas V launch vehicle that will boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft into orbit arrives at the Atlas Spaceflight Operations Center on Cape Canaveral Air Force Station for checkout in preparation for launch. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/ Jim Grossman

KSC-2013-4410

NASA Image and Video Library

2013-12-13

CAPE CANAVERAL, Fla. – At Cape Canaveral Air Force Station, the first stage of the United Launch Alliance Atlas V rocket is lifted for stacking in the Vertical Integration Facility at Launch Complex 41. The vehicle will be used to boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft to orbit. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/Charisse Nahser

KSC-2013-4398

NASA Image and Video Library

2013-12-13

CAPE CANAVERAL, Fla. – At Cape Canaveral Air Force Station's Vertical Integration Facility at Launch Complex 41, a crane is positioned to support stacking of the United Launch Alliance Atlas V rocket that will boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft into orbit. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/Charisse Nahser

KSC-2013-4400

NASA Image and Video Library

2013-12-13

CAPE CANAVERAL, Fla. – At Cape Canaveral Air Force Station, engineers and technicians prepare the United Launch Alliance Atlas V rocket for stacking in the Vertical Integration Facility at Launch Complex 41. The vehicle will be used to boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft to orbit. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/Charisse Nahser

KSC-2013-4389

NASA Image and Video Library

2013-12-12

CAPE CANAVERAL, Fla. – The United Launch Alliance Atlas V first stage booster that will boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft into orbit is being transported from the hangar at the Atlas Spaceflight Operations Center on Cape Canaveral Air Force Station to Launch Complex 41. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/Kim Shiflett

KSC-2013-3793

NASA Image and Video Library

2013-11-01

CAPE CANAVERAL, Fla. – The United Launch Alliance Atlas V launch vehicle that will boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft into orbit arrives at the Atlas Spaceflight Operations Center on Cape Canaveral Air Force Station for checkout in preparation for launch. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/ Jim Grossman

KSC-2013-4423

NASA Image and Video Library

2013-12-13

CAPE CANAVERAL, Fla. – At Cape Canaveral Air Force Station's Launch Complex 41, engineers and technicians support lifting a Centaur second stage for stacking atop a United Launch Alliance Atlas V rocket that will be used to boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft to orbit. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/Charisse Nahser

KSC-2013-4417

NASA Image and Video Library

2013-12-13

CAPE CANAVERAL, Fla. – The United Launch Alliance Centaur second stage that will help boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft into orbit is being transported from the hangar at the Atlas Spaceflight Operations Center on Cape Canaveral Air Force Station to Launch Complex 41. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/Charisse Nahser

KSC-2013-4411

NASA Image and Video Library

2013-12-13

CAPE CANAVERAL, Fla. – At Cape Canaveral Air Force Station, the first stage of the United Launch Alliance Atlas V rocket is lifted for stacking in the Vertical Integration Facility at Launch Complex 41. The vehicle will be used to boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft to orbit. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/Charisse Nahser

KSC-2013-4425

NASA Image and Video Library

2013-12-13

CAPE CANAVERAL, Fla. – At Cape Canaveral Air Force Station's Launch Complex 41, engineers and technicians support lifting a Centaur second stage for stacking atop a United Launch Alliance Atlas V rocket that will be used to boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft to orbit. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/Charisse Nahser

KSC-2013-3789

NASA Image and Video Library

2013-11-01

CAPE CANAVERAL, Fla. – The United Launch Alliance Centaur upper stage that will boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft into orbit is being transported to the hangar at the Atlas Spaceflight Operations Center on Cape Canaveral Air Force Station for checkout in preparation for launch. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/ Jim Grossman

KSC-2013-3794

NASA Image and Video Library

2013-11-01

CAPE CANAVERAL, Fla. – The United Launch Alliance Atlas V launch vehicle that will boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft into orbit arrives at the Atlas Spaceflight Operations Center on Cape Canaveral Air Force Station for checkout in preparation for launch. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/ Jim Grossman

KSC-2013-4393

NASA Image and Video Library

2013-12-12

CAPE CANAVERAL, Fla. – The United Launch Alliance Atlas V first stage booster that will boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft into orbit is being transported from the hangar at the Atlas Spaceflight Operations Center on Cape Canaveral Air Force Station to Launch Complex 41. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/Kim Shiflett

KSC-2013-4408

NASA Image and Video Library

2013-12-13

CAPE CANAVERAL, Fla. – At Cape Canaveral Air Force Station, a technician supports lifting of a United Launch Alliance Atlas V rocket in the Vertical Integration Facility at Launch Complex 41. The vehicle will be used to boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft to orbit. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/Charisse Nahser

KSC-2013-4403

NASA Image and Video Library

2013-12-13

CAPE CANAVERAL, Fla. – At Cape Canaveral Air Force Station, the first stage of the United Launch Alliance Atlas V rocket is lifted for stacking in the Vertical Integration Facility at Launch Complex 41. The vehicle will be used to boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft to orbit. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/Charisse Nahser

KSC-2013-4416

NASA Image and Video Library

2013-12-13

CAPE CANAVERAL, Fla. – At Cape Canaveral Air Force Station, the first stage of the United Launch Alliance Atlas V rocket positioned in the Vertical Integration Facility at Launch Complex 41. The vehicle will be used to boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft to orbit. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/Charisse Nahser

KSC-2013-3784

NASA Image and Video Library

2013-11-01

CAPE CANAVERAL, Fla. – The United Launch Alliance Atlas V launch vehicle that will boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft into orbit is being transported to the hangar at the Atlas Spaceflight Operations Center on Cape Canaveral Air Force Station for checkout in preparation for launch. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/ Jim Grossman

KSC-2013-4405

NASA Image and Video Library

2013-12-13

CAPE CANAVERAL, Fla. – At Cape Canaveral Air Force Station, the first stage of the United Launch Alliance Atlas V rocket is lifted for stacking in the Vertical Integration Facility at Launch Complex 41. The vehicle will be used to boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft to orbit. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/Charisse Nahser

KSC-2013-4422

NASA Image and Video Library

2013-12-13

CAPE CANAVERAL, Fla. – At Cape Canaveral Air Force Station's Launch Complex 41, engineers and technicians support preparations for lifting the Centaur second stage of the United Launch Alliance rocket that will be used to boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft to orbit. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/Charisse Nahser

KSC-2013-4430

NASA Image and Video Library

2013-12-13

CAPE CANAVERAL, Fla. – At Cape Canaveral Air Force Station's Launch Complex 41, engineers and technicians inspect a Centaur second stage that was just stacked atop a United Launch Alliance Atlas V rocket that will be used to boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft to orbit. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/Charisse Nahser

KSC-2013-4392

NASA Image and Video Library

2013-12-12

CAPE CANAVERAL, Fla. – The United Launch Alliance Atlas V first stage booster that will boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft into orbit is being transported from the hangar at the Atlas Spaceflight Operations Center on Cape Canaveral Air Force Station to Launch Complex 41. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/Kim Shiflett

KSC-2013-4401

NASA Image and Video Library

2013-12-13

CAPE CANAVERAL, Fla. – At Cape Canaveral Air Force Station, engineers and technicians prepare the United Launch Alliance Atlas V rocket for stacking in the Vertical Integration Facility at Launch Complex 41. The vehicle will be used to boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft to orbit. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/Charisse Nahser

KSC-2013-3788

NASA Image and Video Library

2013-11-01

CAPE CANAVERAL, Fla. – The United Launch Alliance Atlas V launch vehicle that will boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft into orbit is being transported to the hangar at the Atlas Spaceflight Operations Center on Cape Canaveral Air Force Station for checkout in preparation for launch. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/ Jim Grossman

KSC-2013-4414

NASA Image and Video Library

2013-12-13

CAPE CANAVERAL, Fla. – At Cape Canaveral Air Force Station, the first stage of the United Launch Alliance Atlas V rocket is lifted for stacking in the Vertical Integration Facility at Launch Complex 41. The vehicle will be used to boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft to orbit. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/Charisse Nahser

KSC-2013-4424

NASA Image and Video Library

2013-12-13

CAPE CANAVERAL, Fla. – At Cape Canaveral Air Force Station's Launch Complex 41, engineers and technicians support lifting a Centaur second stage for stacking atop a United Launch Alliance Atlas V rocket that will be used to boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft to orbit. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/Charisse Nahser

KSC-2013-4419

NASA Image and Video Library

2013-12-13

CAPE CANAVERAL, Fla. – The United Launch Alliance Centaur second stage that will help boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft into orbit is being transported from the hangar at the Atlas Spaceflight Operations Center on Cape Canaveral Air Force Station to Launch Complex 41. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/Charisse Nahser

KSC-2013-3787

NASA Image and Video Library

2013-11-01

CAPE CANAVERAL, Fla. – The United Launch Alliance Atlas V launch vehicle that will boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft into orbit is being transported to the hangar at the Atlas Spaceflight Operations Center on Cape Canaveral Air Force Station for checkout in preparation for launch. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/ Jim Grossman

KSC-2013-4390

NASA Image and Video Library

2013-12-12

CAPE CANAVERAL, Fla. – The United Launch Alliance Atlas V first stage booster that will boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft into orbit is being prepared for transport from the hangar at the Atlas Spaceflight Operations Center on Cape Canaveral Air Force Station to Launch Complex 41. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/Kim Shiflett

KSC-2013-4399

NASA Image and Video Library

2013-12-13

CAPE CANAVERAL, Fla. – At Cape Canaveral Air Force Station, engineers and technicians prepare the United Launch Alliance Atlas V rocket for stacking in the Vertical Integration Facility at Launch Complex 41. The vehicle will be used to boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft to orbit. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/Charisse Nahser

KSC-2013-4409

NASA Image and Video Library

2013-12-13

CAPE CANAVERAL, Fla. – At Cape Canaveral Air Force Station, the first stage of the United Launch Alliance Atlas V rocket is lifted for stacking in the Vertical Integration Facility at Launch Complex 41. The vehicle will be used to boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft to orbit. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/Charisse Nahser

KSC-2013-4426

NASA Image and Video Library

2013-12-13

CAPE CANAVERAL, Fla. – At Cape Canaveral Air Force Station's Launch Complex 41, a Centaur second stage is lifted for stacking atop a United Launch Alliance Atlas V rocket that will be used to boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft to orbit. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/Charisse Nahser

KSC-2013-3785

NASA Image and Video Library

2013-11-01

CAPE CANAVERAL, Fla. – The United Launch Alliance Atlas V launch vehicle that will boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft into orbit is being transported to the hangar at the Atlas Spaceflight Operations Center on Cape Canaveral Air Force Station for checkout in preparation for launch. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/ Jim Grossman

KSC-2013-4391

NASA Image and Video Library

2013-12-12

CAPE CANAVERAL, Fla. – The United Launch Alliance Atlas V first stage booster that will boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft into orbit is being transported from the hangar at the Atlas Spaceflight Operations Center on Cape Canaveral Air Force Station to Launch Complex 41. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/Kim Shiflett

KSC-2013-4397

NASA Image and Video Library

2013-12-13

CAPE CANAVERAL, Fla. – At Cape Canaveral Air Force Station's Vertical Integration Facility at Launch Complex 41, a crane is positioned to support stacking of the United Launch Alliance Atlas V rocket that will boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft into orbit. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/Charisse Nahser

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.

Advanced systems engineering and network planning support

NASA Technical Reports Server (NTRS)

Walters, David H.; Barrett, Larry K.; Boyd, Ronald; Bazaj, Suresh; Mitchell, Lionel; Brosi, Fred

1990-01-01

The objective of this task was to take a fresh look at the NASA Space Network Control (SNC) element for the Advanced Tracking and Data Relay Satellite System (ATDRSS) such that it can be made more efficient and responsive to the user by introducing new concepts and technologies appropriate for the 1997 timeframe. In particular, it was desired to investigate the technologies and concepts employed in similar systems that may be applicable to the SNC. The recommendations resulting from this study include resource partitioning, on-line access to subsets of the SN schedule, fluid scheduling, increased use of demand access on the MA service, automating Inter-System Control functions using monitor by exception, increase automation for distributed data management and distributed work management, viewing SN operational control in terms of the OSI Management framework, and the introduction of automated interface management.

Orbiter Interface Unit and Early Communication System

NASA Technical Reports Server (NTRS)

Cobbs, Ronald M.; Cooke, Michael P.; Cox, Gary L.; Ellenberger, Richard; Fink, Patrick W.; Haynes, Dena S.; Hyams, Buddy; Ling, Robert Y.; Neighbors, Helen M.; Phan, Chau T.;

Variable Structure Control of a Hand-Launched Glider

NASA Technical Reports Server (NTRS)

Anderson, Mark R.; Waszak, Martin R.

2005-01-01

Variable structure control system design methods are applied to the problem of aircraft spin recovery. A variable structure control law typically has two phases of operation. The reaching mode phase uses a nonlinear relay control strategy to drive the system trajectory to a pre-defined switching surface within the motion state space. The sliding mode phase involves motion along the surface as the system moves toward an equilibrium or critical point. Analysis results presented in this paper reveal that the conventional method for spin recovery can be interpreted as a variable structure controller with a switching surface defined at zero yaw rate. Application of Lyapunov stability methods show that deflecting the ailerons in the direction of the spin helps to insure that this switching surface is stable. Flight test results, obtained using an instrumented hand-launched glider, are used to verify stability of the reaching mode dynamics.

29 CFR 1926.403 - General requirements.

Code of Federal Regulations, 2011 CFR

2011-07-01

... protect other equipment, the adequacy of the protection thus provided. (iii) Electrical insulation. (iv... switchboards, control panels, switches, circuit breakers, motor controllers, relays, and similar equipment...

Gravity Probe-B (GP-B) Mission and Tracking, Telemetry and Control Subsystem Overview

NASA Technical Reports Server (NTRS)

Kennedy, Paul; Bell, Joseph L. (Technical Monitor)

2001-01-01

The National Aeronautics and Space Administration's (NASA) Marshall Space Flight Center (MSFC) in Huntsville, Alabama will launch the Gravity Probe B (GP-B) space experiment in the Fall of 2002. The GP-B spacecraft was developed to prove Einstein's theory of General Relativity. This paper will provide an overview of the GPB mission and will discuss the design, and test of the spacecraft Tracking, Telemetry and Control (TT&C) subsystem which incorporates NASA's latest generation standard transponder for use with the NASA Tracking and Data Relay Satellite System (TDRSS).

Development of software and hardware models of monitoring, control, and data transfer to improve safety of downhole motor during drilling

NASA Astrophysics Data System (ADS)

Kostarev, S. N.; Sereda, T. G.

2017-10-01

The article is concerned with the problem of transmitting data from telemetric devices in order to provide automated systems for the electric drive control of oil-extracting equipment. The paper given discusses the possibility to use a logging cable as means of signal transfer. Simulation models of signaling and relay-contact circuits for monitoring critical drive parameters are under discussion. The authors suggest applying the operator ⊕ (excluding OR) to increase anti-jamming effects and to get a more reliable noise filter.

Shuttle Ku-band bent-pipe implementation considerations. [for Space Shuttle digital communication systems

NASA Technical Reports Server (NTRS)

Batson, B. H.; Seyl, J. W.; Huth, G. K.

1977-01-01

This paper describes an approach for relay of data-modulated subcarriers from Shuttle payloads through the Shuttle Ku-band communications subsystem (and subsequently through a tracking and data relay satellite system to a ground terminal). The novelty is that a channel originally provided for baseband digital data is shown to be suitable for this purpose; the resulting transmission scheme is referred to as a narrowband bent-pipe scheme. Test results demonstrating the validity of the narrowband bent-pipe mode are presented, and limitations on system performance are described.

Graphics enhanced computer emulation for improved timing-race and fault tolerance control system analysis. [of Centaur liquid-fuel booster

NASA Technical Reports Server (NTRS)

Szatkowski, G. P.

1983-01-01

A computer simulation system has been developed for the Space Shuttle's advanced Centaur liquid fuel booster rocket, in order to conduct systems safety verification and flight operations training. This simulation utility is designed to analyze functional system behavior by integrating control avionics with mechanical and fluid elements, and is able to emulate any system operation, from simple relay logic to complex VLSI components, with wire-by-wire detail. A novel graphics data entry system offers a pseudo-wire wrap data base that can be easily updated. Visual subsystem operations can be selected and displayed in color on a six-monitor graphics processor. System timing and fault verification analyses are conducted by injecting component fault modes and min/max timing delays, and then observing system operation through a red line monitor.

New energy conversion techniques in space, applicable to propulsion

NASA Technical Reports Server (NTRS)

Hertzberg, A.; Sun, K. C.

1989-01-01

The powering of aircraft with laser energy from a solar power satellite may be a promising new approach to the critical problem of the rising cost of fuel for aircraft transportation systems. The result is a nearly fuelless, pollution-free flight transportation system which is cost-competitive with the fuel-conservative airplane of the future. The major components of this flight system include a laser power satellite, relay satellites, laser-powered turbofans and a conventional airframe. The relay satellites are orbiting optical systems which intercept the beam from a power satellite and refocus and redirect the beam to its next target.

78 FR 38356 - 60-Day Notice of Proposed Information Collection: Notice of Proposed Information Collection for...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-26

... Information Collection: Notice of Proposed Information Collection for Disaster Recovery Grant Reporting System... impairments may access this number through TTY by calling the toll-free Federal Relay Service at (800) 877... this number through TTY by calling the toll-free Federal Relay Service at (800) 877-8339. SUPPLEMENTARY...

Tracking and data relay satellite system configuration and tradeoff study. Volume 5: User impact and ground station design, part 1

NASA Technical Reports Server (NTRS)

Hill, T. E.

1972-01-01

The configuration of the user transponder on the Tracking and Data Relay satellite is described. The subjects discussed are: (1) transponder concepts and trades, (2) ground station design, (3) antenna configurations for ground equipment, (4) telemetry facilities, (5) signal categories, and (6) satellite tracking.

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

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.

Tracking and data relay satellite system configuration and tradeoff study. Volume 4: TDRS system operation and control and telecommunications service system, part 1

NASA Technical Reports Server (NTRS)

1972-01-01

Major study areas treated in this volume are: 1) operations and control and 2) the telecommunication service system. The TDRS orbit selection, orbital deployment, ground station visibility, sequence of events from launch to final orbit position, and TDRS control center functions required for stationkeeping, repositioning, attitude control, and antenna pointing are briefly treated as part of the operations and control section. The last topic of this section concerns the operations required for efficiently providing the TDRSS user telecommunication services. The discussion treats functions of the GSFC control and data processing facility, ground station, and TDRS control center. The second major portion of this volume deals with the Telecommunication Service System (TSS) which consists of the ground station, TDRS communication equipment and the user transceiver. A summary of the requirements and objectives for the telecommunication services and a brief summary of the TSS capabilities is followed by communication system analysis, signal design, and equipment design. Finally, descriptions of the three TSS elements are presented.

Application of Phasor Measurement Units for Protection of Distribution Networks with High Penetration of Photovoltaic Sources

NASA Astrophysics Data System (ADS)

Meskin, Matin

The rate of the integration of distributed generation (DG) units to the distribution level to meet the growth in demand increases as a reasonable replacement for costly network expansion. This integration brings many advantages to the consumers and power grids, as well as giving rise to more challenges in relation to protection and control. Recent research has brought to light the negative effects of DG units on short circuit currents and overcurrent (OC) protection systems in distribution networks. Change in the direction of fault current flow, increment or decrement of fault current magnitude, blindness of protection, feeder sympathy trip, nuisance trip of interrupting devices, and the disruption of coordination between protective devices are some potential impacts of DG unit integration. Among other types of DG units, the integration of renewable energy resources into the electric grid has seen a vast improvement in recent years. In particular, the interconnection of photovoltaic (PV) sources to the medium voltage (MV) distribution networks has experienced a rapid increase in the last decade. In this work, the effect of PV source on conventional OC relays in MV distribution networks is shown. It is indicated that the PV output fluctuation, due to changes in solar radiation, causes the magnitude and direction of the current to change haphazardly. These variations may result in the poor operation of OC relays as the main protective devices in the MV distribution networks. In other words, due to the bi-directional power flow characteristic and the fluctuation of current magnitude occurring in the presence of PV sources, a specific setting of OC relays is difficult to realize. Therefore, OC relays may operate in normal conditions. To improve the OC relay operation, a voltage-dependent-overcurrent protection is proposed. Although, this new method prevents the OC relay from maloperation, its ability to detect earth faults and high impedance faults is poor. Thus, a comprehensive protective system is suggested at the end of the dissertation. The proposed method is based on the application of the phasor measurement unit (PMU) and the differential protection method. All of the current magnitudes and angles are collected by PMU and are sent to the phasor data concentrator (PDC), where a differential protection algorithm is applied to these data. If any fault is detected, the trip will be sent back to the corresponding circuit breakers across the network. Higher selectivity, sensitivity, and faster operation in the differential protection are superior to those of other protection schemes. Differential protection operates as unit protection, which means that it operates only when there is a fault in the protection zone. It does not function for faults occurring out of zone. Therefore, no coordination is required between differential protections across the power system. Moreover, the misoperation of this protective scheme is less likely as compared to other protection methods.

Telemetry and control system for interplatform crude loading at the Statfjord Field

DOE Office of Scientific and Technical Information (OSTI.GOV)

Malmin, P.C.; Lassa, P.

1986-01-01

A control system for crude loading to tankers at the Statfjord field has been designed by Mobil Exploration Norway Inc. The objective of the interplatform crude tieline and control system was to allow tanker loading to take place at all times in order to prevent production shutdowns due to loading buoy problems. The control system has been designed to maximize the flexibility of loading operations and meet all safety and regulatory requirements. This paper discusses the design criteria for the crude tieline control system, and describes how these were met by utilizing fail safe telemetry equipment, hardwired permissive relay logicmore » and programmable logic controllers (PLC's). The experience gained from more than three years of operation of the system is reviewed. The system has allowed maximum use of total field storage capacity while loading crude to 125000 DWT tankers nearly every day throughout the year. It has been possible to maintain a high production rate event through periods of difficult weather conditions as experienced in the northern North Sea.« less

Adaptive control of Parkinson's state based on a nonlinear computational model with unknown parameters.

PubMed

Su, Fei; Wang, Jiang; Deng, Bin; Wei, Xi-Le; Chen, Ying-Yuan; Liu, Chen; Li, Hui-Yan

2015-02-01

The objective here is to explore the use of adaptive input-output feedback linearization method to achieve an improved deep brain stimulation (DBS) algorithm for closed-loop control of Parkinson's state. The control law is based on a highly nonlinear computational model of Parkinson's disease (PD) with unknown parameters. The restoration of thalamic relay reliability is formulated as the desired outcome of the adaptive control methodology, and the DBS waveform is the control input. The control input is adjusted in real time according to estimates of unknown parameters as well as the feedback signal. Simulation results show that the proposed adaptive control algorithm succeeds in restoring the relay reliability of the thalamus, and at the same time achieves accurate estimation of unknown parameters. Our findings point to the potential value of adaptive control approach that could be used to regulate DBS waveform in more effective treatment of PD.

The aerial relay system: An energy-efficient solution to the airport congestion problem

NASA Technical Reports Server (NTRS)

Kyser, A. C.

1980-01-01

The ability to transfer airline passengers between aircraft in flight, if adequately developed and integrated into the national air transportation system, could provide significant improvements in transportation-system performance, in terms of airport congestion, fuel consumption, and passenger service. The proposed Aerial Relay System concept, which was developed as a means of exploiting inflight transfer, makes use of large 'cruise liner' aircraft which fly continuously along their routes, docking periodically with short-haul feeder aircraft for exchange of payloads. Preliminary vehicle designs for a representative system are described and the operational feasibility of the concept for the United States in the 1990's is discussed.

Tracking and data relay satellite system configuration and tradeoff study. Volume 5: TDRS spacecraft design, part 1

NASA Technical Reports Server (NTRS)

1972-01-01

A dual spin stabilized TDR spacecraft design is presented for low data rate (LDR) and medium data rate (MDR) user spacecraft telecommunication relay service. The relay satellite provides command and data return channels for unmanned users together with duplex voice and data communication channels for manned user spacecraft. TDRS/ground links are in the Ku band. Command links are provided at UHF for LDR users and S band for MDR users. Voice communication channels are provided at UHF/VHF for LDR users and at S band for MDR users. The spacecraft is designed for launch on the Delta 2914 with system deployment planned for 1978. This volume contains a description of the overall TDR spacecraft configuration, a detailed description of the spacecraft subsystems, a reliability analysis, and a product effectiveness plan.

Target-specific NMR detection of protein-ligand interactions with antibody-relayed 15N-group selective STD.

PubMed

Hetényi, Anasztázia; Hegedűs, Zsófia; Fajka-Boja, Roberta; Monostori, Éva; Kövér, Katalin E; Martinek, Tamás A

2016-12-01

Fragment-based drug design has been successfully applied to challenging targets where the detection of the weak protein-ligand interactions is a key element. 1 H saturation transfer difference (STD) NMR spectroscopy is a powerful technique for this work but it requires pure homogeneous proteins as targets. Monoclonal antibody (mAb)-relayed 15 N-GS STD spectroscopy has been developed to resolve the problem of protein mixtures and impure proteins. A 15 N-labelled target-specific mAb is selectively irradiated and the saturation is relayed through the target to the ligand. Tests on the anti-Gal-1 mAb/Gal-1/lactose system showed that the approach is experimentally feasible in a reasonable time frame. This method allows detection and identification of binding molecules directly from a protein mixture in a multicomponent system.

Optical data communication for Earth observation satellite systems

NASA Astrophysics Data System (ADS)

Fischer, J.; Loecherbach, E.

1991-10-01

The current development status of optical communication engineering in comparison to the conventional microwave systems and the different configurations of the optical data communication for Earth observation satellite systems are described. An outlook to future optical communication satellite systems is given. During the last decade Earth observation became more and more important for the extension of the knowledge about our planet and the human influence on nature. Today pictures taken by satellites are used, for example, to discover mineral resources or to predict harvest, crops, climate, and environment variations and their influence on the population. A new and up to date application for Earth observation satellites can be the verification of disarmament arrangements and the control of crises areas. To solve these tasks a system of Earth observing satellites with sensors tailored to the envisaged mission is necessary. Besides these low Earth orbiting satellites, a global Earth observation system consists of at least two data relay satellites. The communication between the satellites will be established via Inter-Satellite Links (ISL) and Inter-Orbit Links (IOL). On these links, bitrates up to 1 Gbit/s must be taken into account. Due to the increasing scarcity of suitable frequencies, higher carrier frequencies must probably be considered, and possible interference with terrestrial radio relay systems are two main problems for a realization in microwave technique. One important step to tackle these problems is the use of optical frequencies for IOL's and ISL's.

Condensation and jumping relay of droplets on lotus leaf

NASA Astrophysics Data System (ADS)

Lv, Cunjing; Hao, Pengfei; Yao, Zhaohui; Song, Yu; Zhang, Xiwen; He, Feng

2013-07-01

Dynamic behavior of micro water droplet condensed on a lotus leaf with two-tier roughness is studied. Under laboratory environment, the contact angle of the micro droplet on single micro papilla increases smoothly from 80° to 160° during the growth of condensed water. The best-known "self-cleaning" phenomenon will be lost. A striking observation is the out-of-plane jumping relay of condensed droplets triggered by falling droplets, as well as its sustained speed obtained in continuous jumping relays. The underlying mechanism can be used to enhance the automatic removal of dropwise condensation without the help from any external force. The surface tension energy dissipation is the main reason controlling the critical size of jumping droplet and its onset velocity of rebounding.

Tracking and Data Relay Satellite System configuration and tradeoff study. Volume 2: Delta 2914 launched TDRSS, Configuration 2. Part 2: Final Report, 22 August 1972 - 1 April 1973

NASA Technical Reports Server (NTRS)

1973-01-01

Configuration data and design information for a Delta 2914 launched configuration with greatly enhanced telecommunication service over the Part I Delta 2914 configuration is contained. The overall system definition, operations and control, and telecommunication service system, including link budgets are discussed. A brief description of the user transceiver and ground station is presented. A final section includes a summary description of the TDR spacecraft and all the subsystems. The data presented are largely in tabular form.

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

...] Structure and Practices of the Video Relay Service Program: Telecommunications Relay Services and Speech-to... telecommunications relay services (TRS) program continues to offer functional equivalence to all eligible users and... Practices of the Video Relay Service Program; Telecommunications Relay Services and Speech-to-Speech...

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.

Latest Changes to NASA's Laser Communication Relay Demonstration Project

NASA Technical Reports Server (NTRS)

Edwards, Bernard L.; Israel, David J.; Vithlani, Seema K.

2018-01-01

Over the last couple of years, NASA has been making changes to the Laser Communications Relay Demonstration Project (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). The changes made makes LCRD more like a future Earth relay system that has both high speed optical and radio frequency links. This will allow LCRD to demonstrate a more detailed concept of operations for a future operational mission critical Earth relay. LCRD is expected to launch in June 2019 and is expected to be followed a couple of years later with a prototype user terminal on the International Space Station. LCRD's architecture will allow it to serve as a testbed in space and this paper will provide an update of its planned capabilities and experiments.

KSC-2013-3786

NASA Image and Video Library

2013-11-01

CAPE CANAVERAL, Fla. – The United Launch Alliance Atlas V launch vehicle, left, and Centaur upper stage that will boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft into orbit is being transported to the hangar at the Atlas Spaceflight Operations Center on Cape Canaveral Air Force Station for checkout in preparation for launch. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/ Jim Grossman

KSC-2013-4402

NASA Image and Video Library

2013-12-13

CAPE CANAVERAL, Fla. – At Cape Canaveral Air Force Station, engineers and technicians support lifting the first stage of the United Launch Alliance Atlas V rocket during stacking operations in the Vertical Integration Facility at Launch Complex 41. The vehicle will be used to boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft to orbit. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/Charisse Nahser

KSC-2013-4413

NASA Image and Video Library

2013-12-13

CAPE CANAVERAL, Fla. – At Cape Canaveral Air Force Station, a technician support lifting the first stage of the United Launch Alliance Atlas V rocket during stacking operations in the Vertical Integration Facility at Launch Complex 41. The vehicle will be used to boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft to orbit. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/Charisse Nahser

KSC-2013-4420

NASA Image and Video Library

2013-12-13

CAPE CANAVERAL, Fla. – The United Launch Alliance Centaur second stage that will help boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft into orbit arrives at Cape Canaveral Air Force Station's Launch Complex 41. It will be lifted and mounted atop the Atlas V first stage already in position inside the Vertical Integration Facility. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/Charisse Nahser

KSC-2013-4412

NASA Image and Video Library

2013-12-13

CAPE CANAVERAL, Fla. – At Cape Canaveral Air Force Station, engineers and technicians support lifting the first stage of the United Launch Alliance Atlas V rocket during stacking operations in the Vertical Integration Facility at Launch Complex 41. The vehicle will be used to boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft to orbit. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/Charisse Nahser

KSC-2013-3782

NASA Image and Video Library

2013-11-01

PORT CANAVERAL, Fla. – Following arrival at Port Canaveral, Fla., the United Launch Alliance Atlas V first stage and Centaur upper stage that will boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft into orbit is being transported to Cape Canaveral Air Force Station's Atlas Spaceflight Operations Center for checkout in preparation for launch. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/ Kim Shiflett

KSC-2013-4404

NASA Image and Video Library

2013-12-13

CAPE CANAVERAL, Fla. – At Cape Canaveral Air Force Station, engineers and technicians support lifting the first stage of the United Launch Alliance Atlas V rocket during stacking operations in the Vertical Integration Facility at Launch Complex 41. The vehicle will be used to boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft to orbit. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/Charisse Nahser

KSC-2013-3781

NASA Image and Video Library

2013-11-01

PORT CANAVERAL, Fla. – Following arrival at Port Canaveral, Fla., the United Launch Alliance Atlas V first stage and Centaur upper stage that will boost the Tracking and Data Relay Satellite, or TDRS-L, spacecraft into orbit is being transported to Cape Canaveral Air Force Station's Atlas Spaceflight Operations Center for checkout in preparation for launch. TDRS-L is the second of three next-generation satellites designed to ensure vital operational continuity for the NASA Space Network. It is scheduled to launch from Cape Canaveral's Space Launch Complex 41 atop an Atlas V rocket in January 2014. The current Tracking and Data Relay Satellite system consists of eight in-orbit satellites distributed to provide near continuous information relay service to missions such as the Hubble Space Telescope and International Space Station. For more information, visit: http://www.nasa.gov/content/tracking-and-data-relay-satellite-tdrs/ Photo credit: NASA/ Kim Shiflett

Proposals for Codaer (Combat Data Exchange Relay)

DTIC Science & Technology

1949-04-22

Target Reporting 6 CODAER INDICATORS 7 SHAFT POSITION TRANSMISSION AND CODING 9 OPERATIONS CONTROL 10 AA FIRE COORDINATION 10 INTERSHIP PLOTS 12 RELAY...of providing tactical data on at least 500 different targets or friends. The link should be insensitive to jamming and have a high degree of security...gyrations of high speed air targets. This sets the minimum data repetition rate at about 5 reports per second. Better results, particularly in view of

Stereoscopic optical viewing system

DOEpatents

Tallman, C.S.

1986-05-02

An improved optical system which provides the operator with a stereoscopic viewing field and depth of vision, particularly suitable for use in various machines such as electron or laser beam welding and drilling machines. The system features two separate but independently controlled optical viewing assemblies from the eyepiece to a spot directly above the working surface. Each optical assembly comprises a combination of eye pieces, turning prisms, telephoto lenses for providing magnification, achromatic imaging relay lenses and final stage pentagonal turning prisms. Adjustment for variations in distance from the turning prisms to the workpiece, necessitated by varying part sizes and configurations and by the operator's visual accuity, is provided separately for each optical assembly by means of separate manual controls at the operator console or within easy reach of the operator.

Stereoscopic optical viewing system

DOEpatents

Tallman, Clifford S.

1987-01-01

An improved optical system which provides the operator a stereoscopic viewing field and depth of vision, particularly suitable for use in various machines such as electron or laser beam welding and drilling machines. The system features two separate but independently controlled optical viewing assemblies from the eyepiece to a spot directly above the working surface. Each optical assembly comprises a combination of eye pieces, turning prisms, telephoto lenses for providing magnification, achromatic imaging relay lenses and final stage pentagonal turning prisms. Adjustment for variations in distance from the turning prisms to the workpiece, necessitated by varying part sizes and configurations and by the operator's visual accuity, is provided separately for each optical assembly by means of separate manual controls at the operator console or within easy reach of the operator.

Cooperative Lander-Surface/Aerial Microflyer Missions for Mars Exploration

NASA Technical Reports Server (NTRS)

Thakoor, Sarita; Lay, Norman; Hine, Butler; Zornetzer, Steven

2004-01-01

Concepts are being investigated for exploratory missions to Mars based on Bioinspired Engineering of Exploration Systems (BEES), which is a guiding principle of this effort to develop biomorphic explorers. The novelty lies in the use of a robust telecom architecture for mission data return, utilizing multiple local relays (including the lander itself as a local relay and the explorers in the dual role of a local relay) to enable ranges 10 to 1,000 km and downlink of color imagery. As illustrated in Figure 1, multiple microflyers that can be both surface or aerially launched are envisioned in shepherding, metamorphic, and imaging roles. These microflyers imbibe key bio-inspired principles in their flight control, navigation, and visual search operations. Honey-bee inspired algorithms utilizing visual cues to perform autonomous navigation operations such as terrain following will be utilized. The instrument suite will consist of a panoramic imager and polarization imager specifically optimized to detect ice and water. For microflyers, particularly at small sizes, bio-inspired solutions appear to offer better alternate solutions than conventional engineered approaches. This investigation addresses a wide range of interrelated issues, including desired scientific data, sizes, rates, and communication ranges that can be accomplished in alternative mission scenarios. The mission illustrated in Figure 1 offers the most robust telecom architecture and the longest range for exploration with two landers being available as main local relays in addition to an ephemeral aerial probe local relay. The shepherding or metamorphic plane are in their dual role as local relays and image data collection/storage nodes. Appropriate placement of the landing site for the scout lander with respect to the main mission lander can allow coverage of extremely large ranges and enable exhaustive survey of the area of interest. In particular, this mission could help with the path planning and risk mitigation in the traverse of the long-distance surface explorer/rover. The basic requirements of design and operation of BEES to implement the scenarios are discussed. Terrestrial applications of such concepts include distributed aerial/surface measurements of meteorological events, i.e., storm watch, seismic monitoring, reconnaissance, biological chemical sensing, search and rescue, surveillance, autonomous security/ protection agents, and/or delivery and lateral distribution of agents (sensors, surface/subsurface crawlers, clean-up agents). Figure 2 illustrates an Earth demonstration that is in development, and its implementation will illustrate the value of these biomorphic mission concepts.

47 CFR 90.7 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-10-01

.... A regularly interacting group of base, mobile and associated control and fixed relay stations... qualify as unrestricted. Control point. Any place from which a transmitter's functions may be controlled. Control station. An Operational Fixed Station, the transmissions of which are used to control...

47 CFR 90.7 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-10-01

.... A regularly interacting group of base, mobile and associated control and fixed relay stations... qualify as unrestricted. Control point. Any place from which a transmitter's functions may be controlled. Control station. An Operational Fixed Station, the transmissions of which are used to control...

Cross Layer Design for Optimizing Transmission Reliability, Energy Efficiency, and Lifetime in Body Sensor Networks.

PubMed

Chen, Xi; Xu, Yixuan; Liu, Anfeng

2017-04-19

High transmission reliability, energy efficiency, and long lifetime are pivotal issues for wireless body area networks (WBANs. However, these performance metrics are not independent of each other, making it hard to obtain overall improvements through optimizing one single aspect. Therefore, a Cross Layer Design Optimal (CLDO) scheme is proposed to simultaneously optimize transmission reliability, energy efficiency, and lifetime of WBANs from several layers. Firstly, due to the fact that the transmission power of nodes directly influences the reliability of links, the optimized transmission power of different nodes is deduced, which is able to maximize energy efficiency in theory under the premise that requirements on delay and jitter are fulfilled. Secondly, a relay decision algorithm is proposed to choose optimized relay nodes. Using this algorithm, nodes will choose relay nodes that ensure a balance of network energy consumption, provided that all nodes transmit with optimized transmission power and the same packet size. Thirdly, the energy consumption of nodes is still unbalanced even with optimized transmission power because of their different locations in the topology of the network. In addition, packet size also has an impact on final performance metrics. Therefore, a synthesized cross layer method for optimization is proposed. With this method, the transmission power of nodes with more residual energy will be enhanced while suitable packet size is determined for different links in the network, leading to further improvements in the WBAN system. Both our comprehensive theoretical analysis and experimental results indicate that the performance of our proposed scheme is better than reported in previous studies. Relative to the relay selection and power control game (RSPCG) scheme, the CLDO scheme can enhance transmission reliability by more than 44.6% and prolong the lifetime by as much as 33.2%.

Cross Layer Design for Optimizing Transmission Reliability, Energy Efficiency, and Lifetime in Body Sensor Networks

PubMed Central

Chen, Xi; Xu, Yixuan; Liu, Anfeng

2017-01-01

High transmission reliability, energy efficiency, and long lifetime are pivotal issues for wireless body area networks (WBANs). However, these performance metrics are not independent of each other, making it hard to obtain overall improvements through optimizing one single aspect. Therefore, a Cross Layer Design Optimal (CLDO) scheme is proposed to simultaneously optimize transmission reliability, energy efficiency, and lifetime of WBANs from several layers. Firstly, due to the fact that the transmission power of nodes directly influences the reliability of links, the optimized transmission power of different nodes is deduced, which is able to maximize energy efficiency in theory under the premise that requirements on delay and jitter are fulfilled. Secondly, a relay decision algorithm is proposed to choose optimized relay nodes. Using this algorithm, nodes will choose relay nodes that ensure a balance of network energy consumption, provided that all nodes transmit with optimized transmission power and the same packet size. Thirdly, the energy consumption of nodes is still unbalanced even with optimized transmission power because of their different locations in the topology of the network. In addition, packet size also has an impact on final performance metrics. Therefore, a synthesized cross layer method for optimization is proposed. With this method, the transmission power of nodes with more residual energy will be enhanced while suitable packet size is determined for different links in the network, leading to further improvements in the WBAN system. Both our comprehensive theoretical analysis and experimental results indicate that the performance of our proposed scheme is better than reported in previous studies. Relative to the relay selection and power control game (RSPCG) scheme, the CLDO scheme can enhance transmission reliability by more than 44.6% and prolong the lifetime by as much as 33.2%. PMID:28422062

Extreme Tele-Echocardiography: Methodology for Remote Guidance of In-Flight Echocardiography Aboard the International Space Station

NASA Technical Reports Server (NTRS)

Martin, David S.; Borowski, Allan; Bungo, Michael W.; Gladding, Patrick; Greenberg, Neil; Hamilton, Doug; Levine, Benjamin D.; Lee, Stuart M.; Norwood, Kelly; Platts, Steven H.;

AUTOMATIC CALIBRATING SYSTEM FOR PRESSURE TRANSDUCERS

DOEpatents

Amonette, E.L.; Rodgers, G.W.

1958-01-01

An automatic system for calibrating a number of pressure transducers is described. The disclosed embodiment of the invention uses a mercurial manometer to measure the air pressure applied to the transducer. A servo system follows the top of the mercury column as the pressure is changed and operates an analog- to-digital converter This converter furnishes electrical pulses, each representing an increment of pressure change, to a reversible counterThe transducer furnishes a signal at each calibration point, causing an electric typewriter and a card-punch machine to record the pressure at the instant as indicated by the counter. Another counter keeps track of the calibration points so that a number identifying each point is recorded with the corresponding pressure. A special relay control system controls the pressure trend and programs the sequential calibration of several transducers.

Science observations with the IUE using the one-gyro mode

NASA Technical Reports Server (NTRS)

Imhoff, C.; Pitts, R.; Arquilla, R.; Shrader, C.; Perez, M.; Webb, J.

1990-01-01

The International Ultraviolet Explorer (IUE) attitude control system originally included an inertial reference package containing six gyroscopes for three axis stabilization. The science instrument includes a prime and redundant Field Error Sensor (FES) camera for target acquisition and offset guiding. Since launch, four of the six gyroscopes have failed. The current attitude control system utilizes the remaining two gyros and a Fine Sun Sensor (FSS) for three axis stabilization. When the next gyro fails, a new attitude control system will be uplinked, which will relay on the remaining gyro and the FSS for general three axis stabilization. In addition to the FSS, the FES cameras will be required to assist in maintaining fine attitude control during target acquisition. This has required thoroughly determining the characteristics of the FES cameras and the spectrograph aperture plate as well as devising new target acquisition procedures. The results of this work are presented.

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

... 49 Transportation 4 2011-10-01 2011-10-01 false Purpose of inspections and tests; removal from service of relay or device failing to meet test requirements. 234.247 Section 234.247 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION GRADE CROSSING SIGNAL SYSTEM...

The Interplanetary Overlay Networking Protocol Accelerator

NASA Technical Reports Server (NTRS)

Pang, Jackson; Torgerson, Jordan L.; Clare, Loren P.

2008-01-01

A document describes the Interplanetary Overlay Networking Protocol Accelerator (IONAC) an electronic apparatus, now under development, for relaying data at high rates in spacecraft and interplanetary radio-communication systems utilizing a delay-tolerant networking protocol. The protocol includes provisions for transmission and reception of data in bundles (essentially, messages), transfer of custody of a bundle to a recipient relay station at each step of a relay, and return receipts. Because of limitations on energy resources available for such relays, data rates attainable in a conventional software implementation of the protocol are lower than those needed, at any given reasonable energy-consumption rate. Therefore, a main goal in developing the IONAC is to reduce the energy consumption by an order of magnitude and the data-throughput capability by two orders of magnitude. The IONAC prototype is a field-programmable gate array that serves as a reconfigurable hybrid (hardware/ firmware) system for implementation of the protocol. The prototype can decode 108,000 bundles per second and encode 100,000 bundles per second. It includes a bundle-cache static randomaccess memory that enables maintenance of a throughput of 2.7Gb/s, and an Ethernet convergence layer that supports a duplex throughput of 1Gb/s.

Continuous-variable Measurement-device-independent Quantum Relay Network with Phase-sensitive Amplifiers

NASA Astrophysics Data System (ADS)

Li, Fei; Zhao, Wei; Guo, Ying

2018-01-01

Continuous-variable (CV) measurement-device-independent (MDI) quantum cryptography is now heading towards solving the practical problem of implementing scalable quantum networks. In this paper, we show that a solution can come from deploying an optical amplifier in the CV-MDI system, aiming to establish a high-rate quantum network. We suggest an improved CV-MDI protocol using the EPR states coupled with optical amplifiers. It can implement a practical quantum network scheme, where the legal participants create the secret correlations by using EPR states connecting to an untrusted relay via insecure links and applying the multi-entangled Greenberger-Horne-Zeilinger (GHZ) state analysis at relay station. Despite the possibility that the relay could be completely tampered with and imperfect links are subject to the powerful attacks, the legal participants are still able to extract a secret key from network communication. The numerical simulation indicates that the quantum network communication can be achieved in an asymmetric scenario, fulfilling the demands of a practical quantum network. Furthermore, we show that the use of optical amplifiers can compensate the inherent imperfections and improve the secret key rate of the CV-MDI system.

Near field wireless power transfer using curved relay resonators for extended transfer distance

NASA Astrophysics Data System (ADS)

Zhu, D.; Clare, L.; Stark, B. H.; Beeby, S. P.

2015-12-01

This paper investigates the performance of a near field wireless power transfer system that uses curved relay resonator to extend transfer distance. Near field wireless power transfer operates based on the near-field electromagnetic coupling of coils. Such a system can transfer energy over a relatively short distance which is of the same order of dimensions of the coupled coils. The energy transfer distance can be increased using flat relay resonators. Recent developments in printing electronics and e-textiles have seen increasing demand of embedding electronics into fabrics. Near field wireless power transfer is one of the most promising methods to power electronics on fabrics. The concept can be applied to body-worn textiles by, for example, integrating a transmitter coil into upholstery, and a flexible receiver coil into garments. Flexible textile coils take on the shape of the supporting materials such as garments, and therefore curved resonator and receiver coils are investigated in this work. Experimental results showed that using curved relay resonator can effectively extend the wireless power transfer distance. However, as the curvature of the coil increases, the performance of the wireless power transfer, especially the maximum received power, deteriorates.

Supervisory autonomous local-remote control system design: Near-term and far-term applications

NASA Technical Reports Server (NTRS)

Zimmerman, Wayne; Backes, Paul

1993-01-01

The JPL Supervisory Telerobotics Laboratory (STELER) has developed a unique local-remote robot control architecture which enables management of intermittent bus latencies and communication delays such as those expected for ground-remote operation of Space Station robotic systems via the TDRSS communication platform. At the local site, the operator updates the work site world model using stereo video feedback and a model overlay/fitting algorithm which outputs the location and orientation of the object in free space. That information is relayed to the robot User Macro Interface (UMI) to enable programming of the robot control macros. The operator can then employ either manual teleoperation, shared control, or supervised autonomous control to manipulate the object under any degree of time-delay. The remote site performs the closed loop force/torque control, task monitoring, and reflex action. This paper describes the STELER local-remote robot control system, and further describes the near-term planned Space Station applications, along with potential far-term applications such as telescience, autonomous docking, and Lunar/Mars rovers.

Test and control computer user's guide for a digital beam former test system

NASA Technical Reports Server (NTRS)

Alexovich, Robert E.; Mallasch, Paul G.

1992-01-01

A Digital Beam Former Test System was developed to determine the effects of noise, interferers and distortions, and digital implementations of beam forming as applied to the Tracking and Data Relay Satellite 2 (TDRS 2) architectures. The investigation of digital beam forming with application to TDRS 2 architectures, as described in TDRS 2 advanced concept design studies, was conducted by the NASA/Lewis Research Center for NASA/Goddard Space Flight Center. A Test and Control Computer (TCC) was used as the main controlling element of the digital Beam Former Test System. The Test and Control Computer User's Guide for a Digital Beam Former Test System provides an organized description of the Digital Beam Former Test System commands. It is written for users who wish to conduct tests of the Digital Beam forming Test processor using the TCC. The document describes the function, use, and syntax of the TCC commands available to the user while summarizing and demonstrating the use of the commands wtihin DOS batch files.

Enhancing synchrony in chaotic oscillators by dynamic relaying

NASA Astrophysics Data System (ADS)

Banerjee, Ranjib; Ghosh, Dibakar; Padmanaban, E.; Ramaswamy, R.; Pecora, L. M.; Dana, Syamal K.

2012-02-01

In a chain of mutually coupled oscillators, the coupling threshold for synchronization between the outermost identical oscillators decreases when a type of impurity (in terms of parameter mismatch) is introduced in the inner oscillator(s). The outer oscillators interact indirectly via dynamic relaying, mediated by the inner oscillator(s). We confirm this enhancing of critical coupling in the chaotic regimes of the Lorenz system, in the Rössler system in the absence of coupling delay, and in the Mackey-Glass system with delay coupling. The enhancing effect is experimentally verified in the electronic circuit of Rössler oscillators.

Disrupting the Myosin Converter-Relay Interface Impairs Drosophila Indirect Flight Muscle Performance

PubMed Central

Ramanath, Seemanti; Wang, Qian; Bernstein, Sanford I.; Swank, Douglas M.

2011-01-01

Structural interactions between the myosin converter and relay domains have been proposed to be critical for the myosin power stroke and muscle power generation. We tested this hypothesis by mutating converter residue 759, which interacts with relay residues I508, N509, and D511, to glutamate (R759E) and determined the effect on Drosophila indirect flight muscle mechanical performance. Work loop analysis of mutant R759E indirect flight muscle fibers revealed a 58% and 31% reduction in maximum power generation (PWL) and the frequency at which maximum power (fWL) is generated, respectively, compared to control fibers at 15°C. Small amplitude sinusoidal analysis revealed a 30%, 36%, and 32% reduction in mutant elastic modulus, viscous modulus, and mechanical rate constant 2πb, respectively. From these results, we infer that the mutation reduces rates of transitions through work-producing cross-bridge states and/or force generation during strongly bound states. The reductions in muscle power output, stiffness, and kinetics were physiologically relevant, as mutant wing beat frequency and flight index decreased about 10% and 45% compared to control flies at both 15°C and 25°C. Thus, interactions between the relay loop and converter domain are critical for lever-arm and catalytic domain coordination, high muscle power generation, and optimal Drosophila flight performance. PMID:21889448

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

...] Speech-to-Speech and Internet Protocol (IP) Speech-to-Speech Telecommunications Relay Services... Internet Protocol (IP) Speech-to-Speech Telecommunications Relay Services; Telecommunications Relay... (IP Relay) and video relay service (VRS), the Commission should bundle national STS outreach efforts...

Photosensitized H2 Production Using a Zinc Porphyrin-Substituted Protein, Platinum Nanoparticles, and Ascorbate with No Electron Relay: Participation of Good's Buffers.

PubMed

Clark, Emily R; Kurtz, Donald M

2017-04-17

Development of efficient light-driven splitting of water, 2H 2 O → 2H 2 + O 2 , often attempts to optimize photosensitization of the reductive and oxidative half-reactions individually. Numerous homogeneous and heterogeneous systems have been developed for photochemical stimulation of the reductive half reaction, 2H + + 2e - → H 2 . These systems generally consist of various combinations of a H + reduction catalyst, a photosensitizer (PS), and a "sacrificial" electron donor. Zinc(II)-porphyrins (ZnPs) have frequently been used as PSs for H 2 generation, but they are subject to various self-quenching processes in aqueous solutions. Colloidal platinum in nanoparticle form (Pt NP) is a classical H + reduction catalyst using ZnP photosensitizers, but efficient photosensitized H 2 generation requires an electron relay molecule between ZnP and Pt NP. The present report describes an aqueous system for visible (white) light-sensitized generation of H 2 using a protein-embedded Zn(II)-protoporphyrin IX as PS and Pt NP as H + reduction catalyst without an added electron relay. This system operated efficiently in piperazino- and morpholino-alkylsulfonic acid (Good's buffers), which served as sacrificial electron donors. The system also required ascorbate at relatively modest concentrations, which stabilized the Zn(II)-protoporphyrin IX against photodegradation. In the absence of an electron relay molecule, the photosensitized H 2 generation must involve formation of at least a transient complex between a protein-embedded Zn(II)-protoporphyrin IX species and Pt NP.

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.

Retransmission of hydrometric data in Canada

NASA Technical Reports Server (NTRS)

Halliday, R. A. (Principal Investigator); Reid, I. A.

1978-01-01

The author has identified the following significant results. The LANDSAT program has demonstrated that polar orbiting satellites can be used to relay hydrologic data from any part of Canada to a user without difficulty and at low cost. These data can be used for many operational purposes, the most important of which were identified as follows: hydroelectric power plant operation; water supply for municipalities, industries, and irrigation; navigation; flood forecasting; operation of flood control structures and systems; and recreation.

Two-Lens, Anamorphic, Brewster-Angle, Fourier-Transform Relay

NASA Astrophysics Data System (ADS)

Berggren, Ralph R.

1987-06-01

A two-lens system provides a simple and versatile means to relay a laser beam. The pair of lenses can provide true volume imaging, reproducing both amplitude and phase of the input beam. By using cylindrical lenses it is possible to change the aspect ratio of the beam. By adjusting the cylindrical curvatures, it is possible to minimize reflections by tilting the lenses at the Brewster angle.

Commercial space policy - Theory and practice

NASA Technical Reports Server (NTRS)

Freibaum, Jerry

1986-01-01

NASA policy toward commercial space ventures is summarized and illustrated with a proposed system for mobile communications through satellite links (MSAT). The government's, i.e., NASA's, role in commercial space ventures is to provide funding and expertise to high risk projects with prospective large returns, provided no vital public services are displaced. MSAT would be realized with a relay spacecraft in GEO, linking mobile radios costing in the range $500-2500. The experimental ATS-6 satellite would be the first generation relay. It is estimated that by the 1990s a spacecraft with a 20-55 m antenna could provide transmission relays for between 640,000 to about 2.5 million nonurban communications units.

Design and implementation of green intelligent lights based on the ZigBee

NASA Astrophysics Data System (ADS)

Gan, Yong; Jia, Chunli; Zou, Dongyao; Yang, Jiajia; Guo, Qianqian

2013-03-01

By analysis of the low degree of intelligence of the traditional lighting control methods, the paper uses the singlechip microcomputer for the control core, and uses a pyroelectric infrared technology to detect the existence of the human body, light sensors to sense the light intensity; the interface uses infrared sensor module, photosensitive sensor module, relay module to transmit the signal, which based on ZigBee wireless network. The main function of the design is to realize that the lighting can intelligently adjust the brightness according to the indoor light intensity when people in door, and it can turn off the light when people left. The circuit and program design of this system is flexible, and the system achieves the effect of intelligent energy saving control.

Endovascular treatment of patients with types A and B thoracic aortic dissection using Relay thoracic stent-grafts: results from the RESTORE Patient Registry.

PubMed

Zipfel, Burkhart; Czerny, Martin; Funovics, Martin; Coppi, Gioacchino; Ferro, Carlo; Rousseau, Hervé; Berti, Sergio; Tealdi, Domenico G; Riambau, Vincent; Mangialardi, Nicola; Sassi, Carlo

2011-04-01

To evaluate the safety and performance of Relay stent-grafts in patients with acute or chronic aortic dissections. Patients with types A or B aortic dissections suitable for treatment with Relay stent-grafts and followed for 2 years after thoracic endovascular aortic repair (TEVAR) were identified from a company-sponsored registry database established in January 2006. Ninety-one consecutive patients (69 men; mean age 65 years) underwent TEVAR with Relay stent-grafts for dissection. Most patients (76, 84%) had type B dissections; 61 of all patients were classified as chronic and 30 as acute. The technical success rate was 95% (97% in acute, 95% in chronic, and 93% in type B dissections). The type I endoleak rate was 7% (7% in acute and 8% in chronic dissections); all occurred in patients with type B dissections. Paraplegia, paraparesis, and stroke occurred in 4, 1, and 2 patients, respectively; 2 cases of paraplegia occurred in patients with acute type B dissections. Thirty-day mortality was 8% (13% in acute and 5% in chronic dissections); all deaths occurred in patients with type B dissections. The 2-year survival rate was 82% in the overall population and 84% in patients with type B dissections. The combination of Relay's features, such as stent conformability, radial force, atraumatic design, and controlled deployment and fixation, may contribute to the safety of the Relay stent-grafts for the treatment of thoracic aortic dissections, including acute and chronic type B dissections.

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

... Relay Service (IP Relay) providers; Adopts rules to protect the privacy of customer information relating... 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 #0;#0;Federal Register...

Proceedings of the American Power Conference. Volume 60-1

DOE Office of Scientific and Technical Information (OSTI.GOV)

McBride, A.E.

1998-12-01

The American Power Conference, 60th annual meeting, 1998, addressed reliability and economy as related to technology for competition and globalization. The topics of the papers included needs and advances in power engineering education, global climate change, distributed generation, the critical role of the nations largest coal, nuclear and hydropower stations, advances in generation technology, financing electric power projects, successful deregulation, year 2000 outlook for equipment conflict with information and control, system planning, asset management, relay and communication, particulate and SO{sub x} control, environmental protection compliance strategies, fuel cells, gas turbines, renewable energy, steam turbines, and cost reduction strategies.

Proceedings of the American Power Conference. Volume 60-2

DOE Office of Scientific and Technical Information (OSTI.GOV)

McBride, A.E.

1998-12-01

The American Power Conference, 60th annual meeting, 1998, addressed reliability and economy as related to technology for competition and globalization. The topics of the papers included needs and advances in power engineering education, global climate change, distributed generation, the critical role of the nations largest coal, nuclear and hydropower stations, advances in generation technology, financing electric power projects, successful deregulation, year 2000 outlook for equipment conflict with information and control, system planning, asset management, relay and communication, particulate and SO{sub x} control, environmental protection compliance strategies, fuel cells, gas turbines, renewable energy, steam turbines, and cost reduction strategies.

Non-Pilot Protection of the HVDC Grid

NASA Astrophysics Data System (ADS)

Badrkhani Ajaei, Firouz

This thesis develops a non-pilot protection system for the next generation power transmission system, the High-Voltage Direct Current (HVDC) grid. The HVDC grid protection system is required to be (i) adequately fast to prevent damages and/or converter blocking and (ii) reliable to minimize the impacts of faults. This study is mainly focused on the Modular Multilevel Converter (MMC) -based HVDC grid since the MMC is considered as the building block of the future HVDC systems. The studies reported in this thesis include (i) developing an enhanced equivalent model of the MMC to enable accurate representation of its DC-side fault response, (ii) developing a realistic HVDC-AC test system that includes a five-terminal MMC-based HVDC grid embedded in a large interconnected AC network, (iii) investigating the transient response of the developed test system to AC-side and DC-side disturbances in order to determine the HVDC grid protection requirements, (iv) investigating the fault surge propagation in the HVDC grid to determine the impacts of the DC-side fault location on the measured signals at each relay location, (v) designing a protection algorithm that detects and locates DC-side faults reliably and sufficiently fast to prevent relay malfunction and unnecessary blocking of the converters, and (vi) performing hardware-in-the-loop tests on the designed relay to verify its potential to be implemented in hardware. The results of the off-line time domain transients studies in the PSCAD software platform and the real-time hardware-in-the-loop tests using an enhanced version of the RTDS platform indicate that the developed HVDC grid relay meets all technical requirements including speed, dependability, security, selectivity, and robustness. Moreover, the developed protection algorithm does not impose considerable computational burden on the hardware.

Earth Orbiting Support Systems for commercial low Earth orbit data relay: Assessing architectures through tradespace exploration

NASA Astrophysics Data System (ADS)

Palermo, Gianluca; Golkar, Alessandro; Gaudenzi, Paolo

2015-06-01

As small satellites and Sun Synchronous Earth Observation systems are assuming an increased role in nowadays space activities, including commercial investments, it is of interest to assess how infrastructures could be developed to support the development of such systems and other spacecraft that could benefit from having a data relay service in Low Earth Orbit (LEO), as opposed to traditional Geostationary relays. This paper presents a tradespace exploration study of the architecture of such LEO commercial satellite data relay systems, here defined as Earth Orbiting Support Systems (EOSS). The paper proposes a methodology to formulate architectural decisions for EOSS constellations, and enumerate the corresponding tradespace of feasible architectures. Evaluation metrics are proposed to measure benefits and costs of architectures; lastly, a multicriteria Pareto criterion is used to downselect optimal architectures for subsequent analysis. The methodology is applied to two case studies for a set of 30 and 100 customer-spacecraft respectively, representing potential markets for LEO services in Exploration, Earth Observation, Science, and CubeSats. Pareto analysis shows how increased performance of the constellation is always achieved by an increased node size, as measured by the gain of the communications antenna mounted on EOSS spacecraft. On the other hand, nonlinear trends in optimal orbital altitude, number of satellites per plane, and number of orbital planes, are found in both cases. An upward trend in individual node memory capacity is found, although never exceeding 256 Gbits of onboard memory for both cases that have been considered, assuming the availability of a polar ground station for EOSS data downlink. System architects can use the proposed methodology to identify optimal EOSS constellations for a given service pricing strategy and customer target, thus identifying alternatives for selection by decision makers.

47 CFR 90.7 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-10-01

... interacting group of base, mobile and associated control and fixed relay stations intended to provide land... one that does not qualify as unrestricted. Control point. Any place from which a transmitter's functions may be controlled. Control station. An Operational Fixed Station, the transmissions of which are...

47 CFR 90.7 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-10-01

... interacting group of base, mobile and associated control and fixed relay stations intended to provide land... one that does not qualify as unrestricted. Control point. Any place from which a transmitter's functions may be controlled. Control station. An Operational Fixed Station, the transmissions of which are...

47 CFR 90.7 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-10-01

... interacting group of base, mobile and associated control and fixed relay stations intended to provide land... one that does not qualify as unrestricted. Control point. Any place from which a transmitter's functions may be controlled. Control station. An Operational Fixed Station, the transmissions of which are...

Techniques for analyzing and utilizing the rain gauges at the NASA White Sands Test Facility. [Tracking and Data Relay Satellite System ground station

NASA Technical Reports Server (NTRS)

Kalagher, R. J.

1973-01-01

Ten tipping bucket rain gauges have been installed at the NASA WSTF for the purpose of determining rainfall characteristics in this area which may affect the performance of the NASA Tracking and Data Relay Satellite System. A plan is presented for analyzing and utilizing the data which will be obtained during the course of this experiment. Also included is a description of a computer program which has been written to aid in the analysis.

Joint subchannel pairing and power control for cognitive radio networks with amplify-and-forward relaying.

PubMed

Shen, Yanyan; Wang, Shuqiang; Wei, Zhiming

2014-01-01

Dynamic spectrum sharing has drawn intensive attention in cognitive radio networks. The secondary users are allowed to use the available spectrum to transmit data if the interference to the primary users is maintained at a low level. Cooperative transmission for secondary users can reduce the transmission power and thus improve the performance further. We study the joint subchannel pairing and power allocation problem in relay-based cognitive radio networks. The objective is to maximize the sum rate of the secondary user that is helped by an amplify-and-forward relay. The individual power constraints at the source and the relay, the subchannel pairing constraints, and the interference power constraints are considered. The problem under consideration is formulated as a mixed integer programming problem. By the dual decomposition method, a joint optimal subchannel pairing and power allocation algorithm is proposed. To reduce the computational complexity, two suboptimal algorithms are developed. Simulations have been conducted to verify the performance of the proposed algorithms in terms of sum rate and average running time under different conditions.

The fuzzy system classifier using an intelligent mattress

NASA Astrophysics Data System (ADS)

Hnatiuc, Mihaela; Caruntu, George; Sarbu, Vasile

2009-01-01

Quality sleep enables your body and mind to be efficient during the day. The good rest of subject on bed depends by many factors; one of them can be the physical discomfort. In this paper one presents the medical system to prevent the discomfort and to identify the subject behavior during the sleep. The epochs of the sleep are classified using the fuzzy system with many inputs. The aim of this analysis is to realize an expert system to diagnose the sleep. A good diagnostic is obtained if the patient is supervised along all day. The system has a microsystem to control, command the pressure sensors and the relay for tuning the airbags pressure.

Network command processing system overview

NASA Technical Reports Server (NTRS)

Nam, Yon-Woo; Murphy, Lisa D.

1993-01-01

The Network Command Processing System (NCPS) developed for the National Aeronautics and Space Administration (NASA) Ground Network (GN) stations is a spacecraft command system utilizing a MULTIBUS I/68030 microprocessor. This system was developed and implemented at ground stations worldwide to provide a Project Operations Control Center (POCC) with command capability for support of spacecraft operations such as the LANDSAT, Shuttle, Tracking and Data Relay Satellite, and Nimbus-7. The NCPS consolidates multiple modulation schemes for supporting various manned/unmanned orbital platforms. The NCPS interacts with the POCC and a local operator to process configuration requests, generate modulated uplink sequences, and inform users of the ground command link status. This paper presents the system functional description, hardware description, and the software design.

Laser aircraft. [using kerosene

NASA Technical Reports Server (NTRS)

Hertzberg, A.; Sun, K.; Jones, W. S.

1979-01-01

The concept of a laser-powered aircraft is discussed. Laser flight would be completely compatible with existing airports and air-traffic control, with the airplane using kerosene only power, up to a cruising altitude of 9 km where the laser satellite would lock on and beam laser energy to it. Two major components make up the laser turbofan, a heat exchanger for converting laser radiation into thermal energy, and conventional turbomachinery. The laser power satellite would put out 42 Mw using a solar-powered thermal engine to generate electrical power for the closed-cycle supersonic electric discharge CO laser, whose radiators, heat exchangers, supersonic diffuser, and ducting will amount to 85% of the total subsystem mass. Relay satellites will be used to intercept the beam from the laser satellite, correct outgoing beam aberrations, and direct the beam to the next target. A 300-airplane fleet with transcontinental range is projected to save enough kerosene to equal the energy content of the entire system, including power and relay satellites, in one year.

Development of a system for transferring images via a network: supporting a regional liaison.

PubMed

Mihara, Naoki; Manabe, Shiro; Takeda, Toshihiro; Shinichirou, Kitamura; Junichi, Murakami; Kouji, Kiso; Matsumura, Yasushi

2013-01-01

We developed a system that transfers images via network and started using them in our hospital's PACS (Picture Archiving and Communication Systems) in 2006. We are pleased to report that the system has been re-developed and has been running so that there will be a regional liaison in the future. It has become possible to automatically transfer images simply by selecting the destination hospital that is registered in advance at the relay server. The gateway of this system can send images to a multi-center, relay management server, which receives the images and resends them. This system has the potential to be useful for image exchange, and to serve as a regional medical liaison.

Stinger Post Hybrid Simulation: Design Description and Users’ Manual

DTIC Science & Technology

1983-04-01

function of three variables. Table 4 MVFG Modes £ ?*" Mode Function Number Argument Number Trunking Station Address Output Hole Argument...between JA and J7. This permits the signal to control a normally-open, single-throw minature relay. It closes the remote operate line when a logic...logic functions are also performed on the card. A normally- open, single-throw minature relay (U5) and an AND gate (1/4 of Ul) are used to perform the

Mitigation of Remedial Action Schemes by Decentralized Robust Governor Control

DOE Office of Scientific and Technical Information (OSTI.GOV)

Elizondo, Marcelo A.; Marinovici, Laurentiu D.; Lian, Jianming

This paper presents transient stability improvement by a new distributed hierarchical control architecture (DHC). The integration of remedial action schemes (RAS) to the distributed hierarchical control architecture is studied. RAS in power systems are designed to maintain stability and avoid undesired system conditions by rapidly switching equipment and/or changing operating points according to predetermined rules. The acceleration trend relay currently in use in the US western interconnection is an example of RAS that trips generators to maintain transient stability. The link between RAS and DHC is through fast acting robust turbine/governor control that can also improve transient stability. In thismore » paper, the influence of the decentralized robust turbine/governor control on the design of RAS is studied. Benefits of combining these two schemes are increasing power transfer capability and mitigation of RAS generator tripping actions; the later benefit is shown through simulations.« less

Smoothing tautologies, hidden dynamics, and sigmoid asymptotics for piecewise smooth systems

NASA Astrophysics Data System (ADS)

Jeffrey, Mike R.

2015-10-01

Switches in real systems take many forms, such as impacts, electronic relays, mitosis, and the implementation of decisions or control strategies. To understand what is lost, and what can be retained, when we model a switch as an instantaneous event, requires a consideration of so-called hidden terms. These are asymptotically vanishing outside the switch, but can be encoded in the form of nonlinear switching terms. A general expression for the switch can be developed in the form of a series of sigmoid functions. We review the key steps in extending Filippov's method of sliding modes to such systems. We show how even slight nonlinear effects can hugely alter the behaviour of an electronic control circuit, and lead to "hidden" attractors inside the switching surface.

Smoothing tautologies, hidden dynamics, and sigmoid asymptotics for piecewise smooth systems.

PubMed

Jeffrey, Mike R

2015-10-01

Switches in real systems take many forms, such as impacts, electronic relays, mitosis, and the implementation of decisions or control strategies. To understand what is lost, and what can be retained, when we model a switch as an instantaneous event, requires a consideration of so-called hidden terms. These are asymptotically vanishing outside the switch, but can be encoded in the form of nonlinear switching terms. A general expression for the switch can be developed in the form of a series of sigmoid functions. We review the key steps in extending Filippov's method of sliding modes to such systems. We show how even slight nonlinear effects can hugely alter the behaviour of an electronic control circuit, and lead to "hidden" attractors inside the switching surface.

Smoothing tautologies, hidden dynamics, and sigmoid asymptotics for piecewise smooth systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jeffrey, Mike R., E-mail: mike.jeffrey@bristol.ac.uk

2015-10-15

Switches in real systems take many forms, such as impacts, electronic relays, mitosis, and the implementation of decisions or control strategies. To understand what is lost, and what can be retained, when we model a switch as an instantaneous event, requires a consideration of so-called hidden terms. These are asymptotically vanishing outside the switch, but can be encoded in the form of nonlinear switching terms. A general expression for the switch can be developed in the form of a series of sigmoid functions. We review the key steps in extending Filippov's method of sliding modes to such systems. We showmore » how even slight nonlinear effects can hugely alter the behaviour of an electronic control circuit, and lead to “hidden” attractors inside the switching surface.« less

Vacuum system of the cyclotrons in VECC, Kolkata

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roy, Anindya; Bhole, R.B.; Akhtar, J.

2011-07-01

The vacuum system of the K=130 Room Temperature Cyclotron (RTC) (operational since 1978) has been recently modernized and the same of the K{sub bend}=520 Superconducting Cyclotron (SCC), currently under commissioning, is being deployed for remote monitoring and control. The vacuum system of RTC is designed to achieve and maintain vacuum level of 2 X 10{sup -6} mbar inside 23 m{sup 3} volume of Resonator tank and DEE tank. This has been upgraded by replacing several valves, Freon units, gauges and pumps. The relay based manual control system has been replaced by PLC based automated system. The SCC vacuum system alsomore » has an elaborate arrangement comprising of turbo molecular pumping modules with associated isolation valves and characteristic gauges. This paper describes essential elements, typically used to obtain high (1X10{sup -7} mbar) vacuum using rotary pumps, diffusion pumps and cold traps/turbo-molecular pumps and other system components such as valves, gauges and baffles. The supervisory control methodology/scheme of both the vacuum systems, developed in-house using EPICS (Experimental Physics and Industrial Control System), a standard open-source software tool for designing distributed control system, is also elaborated here. (author)« less

A bioinspired redox relay that mimics radical interactions of the Tyr-His pairs of photosystem II

NASA Astrophysics Data System (ADS)

Megiatto, Jackson D., Jr.; Méndez-Hernández, Dalvin D.; Tejeda-Ferrari, Marely E.; Teillout, Anne-Lucie; Llansola-Portolés, Manuel J.; Kodis, Gerdenis; Poluektov, Oleg G.; Rajh, Tijana; Mujica, Vladimiro; Groy, Thomas L.; Gust, Devens; Moore, Thomas A.; Moore, Ana L.

2014-05-01

In water-oxidizing photosynthetic organisms, light absorption generates a powerfully oxidizing chlorophyll complex (P680•+) in the photosystem II reaction centre. This is reduced via an electron transfer pathway from the manganese-containing water-oxidizing catalyst, which includes an electron transfer relay comprising a tyrosine (Tyr)-histidine (His) pair that features a hydrogen bond between a phenol group and an imidazole group. By rapidly reducing P680•+, the relay is thought to mitigate recombination reactions, thereby ensuring a high quantum yield of water oxidation. Here, we show that an artificial reaction centre that features a benzimidazole-phenol model of the Tyr-His pair mimics both the short-internal hydrogen bond in photosystem II and, using electron paramagnetic resonance spectroscopy, the thermal relaxation that accompanies proton-coupled electron transfer. Although this artificial system is much less complex than the natural one, theory suggests that it captures the essential features that are important in the function of the relay.

Network Coding in Relay-based Device-to-Device Communications

PubMed Central

Huang, Jun; Gharavi, Hamid; Yan, Huifang; Xing, Cong-cong

2018-01-01

Device-to-Device (D2D) communications has been realized as an effective means to improve network throughput, reduce transmission latency, and extend cellular coverage in 5G systems. Network coding is a well-established technique known for its capability to reduce the number of retransmissions. In this article, we review state-of-the-art network coding in relay-based D2D communications, in terms of application scenarios and network coding techniques. We then apply two representative network coding techniques to dual-hop D2D communications and present an efficient relay node selecting mechanism as a case study. We also outline potential future research directions, according to the current research challenges. Our intention is to provide researchers and practitioners with a comprehensive overview of the current research status in this area and hope that this article may motivate more researchers to participate in developing network coding techniques for different relay-based D2D communications scenarios. PMID:29503504

Materials testing of the IUS techroll seal material

NASA Technical Reports Server (NTRS)

Nichols, R. L.; Hall, W. B.

1984-01-01

As a part of the investigation of the control system failure Inertial Upper Stage on IUS-1 flight to position a Tracking and Data Relay Satellite (TDRS) in geosynchronous orbit, the materials utilized in the techroll seal are evaluated for possible failure models. Studies undertaken included effect of temperature on the strength of the system, effect of fatigue on the strength of the system, thermogravimetric analysis, thermomechanical analysis, differential scanning calorimeter analysis, dynamic mechanical analysis, and peel test. The most likely failure mode is excessive temperature in the seal. In addition, the seal material is susceptible to fatigue damage which could be a contributing factor.