Application of digital control techniques for satellite medium power DC-DC converters

NASA Astrophysics Data System (ADS)

Skup, Konrad R.; Grudzinski, Pawel; Nowosielski, Witold; Orleanski, Piotr; Wawrzaszek, Roman

2010-09-01

The objective of this paper is to present a work concerning a digital control loop system for satellite medium power DC-DC converters that is done in Space Research Centre. The whole control process of a described power converter bases on a high speed digital signal processing. The paper presents a development of a FPGA digital controller for voltage mode stabilization that was implemented using VHDL. The described controllers are a classical digital PID controller and a bang-bang controller. The used converter for testing is a simple model of 5-20 W, 200 kHz buck power converter. A high resolution digital PWM approach is presented. Additionally a simple and effective solution of filtering of an analog-to-digital converter output is presented.

Nuclear Science Symposium, 23rd, Scintillation and Semiconductor Counter Symposium, 15th, and Nuclear Power Systems Symposium, 8th, New Orleans, La., October 20-22, 1976, Proceedings

NASA Technical Reports Server (NTRS)

Wagner, L. J.

1977-01-01

The volume includes papers on semiconductor radiation detectors of various types, components of radiation detection and dosimetric systems, digital and microprocessor equipment in nuclear industry and science, and a wide variety of applications of nuclear radiation detectors. Semiconductor detectors of X-rays, gamma radiation, heavy ions, neutrons, and other nuclear particles, plastic scintillator arrays, drift chambers, spark wire chambers, and radiation dosimeter systems are reported on. Digital and analog conversion systems, digital data and control systems, microprocessors, and their uses in scientific research and nuclear power plants are discussed. Large-area imaging and biomedical nucleonic instrumentation, nuclear power plant safeguards, reactor instrumentation, nuclear power plant instrumentation, space instrumentation, and environmental instrumentation are dealt with. Individual items are announced in this issue.

Hybrid acousto-optic and digital equalization for microwave digital radio channels

NASA Astrophysics Data System (ADS)

Anderson, C. S.; Vanderlugt, A.

1990-11-01

Digital radio transmission systems use complex modulation schemes that require powerful signal-processing techniques to correct channel distortions and to minimize BERs. This paper proposes combining the computation power of acoustooptic processing and the accuracy of digital processing to produce a hybrid channel equalizer that exceeds the performance of digital equalization alone. Analysis shows that a hybrid equalizer for 256-level quadrature amplitude modulation (QAM) performs better than a digital equalizer for 64-level QAM.

Digital intelligent booster for DCC miniature train networks

NASA Astrophysics Data System (ADS)

Ursu, M. P.; Condruz, D. A.

2017-08-01

Modern miniature trains are now driven by means of the DCC (Digital Command and Control) system, which allows the human operator or a personal computer to launch commands to each individual train or even to control different features of the same train. The digital command station encodes these commands and sends them to the trains by means of electrical pulses via the rails of the railway network. Due to the development of the miniature railway network, it may happen that the power requirement of the increasing number of digital locomotives, carriages and accessories exceeds the nominal output power of the digital command station. This digital intelligent booster relieves the digital command station from powering the entire railway network all by itself, and it automatically handles the multiple powered sections of the network. This electronic device is also able to detect and process short-circuits and overload conditions, without the intervention of the digital command station.

Migration of Older to New Digital Control Systems in Nuclear Power Plant Main Control Rooms

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

Kovesdi, Casey Robert; Joe, Jeffrey Clark

The United States (U.S.) Department of Energy (DOE) Office of Nuclear Energy (NE) has the primary mission to advance nuclear power by resolving socio-technical issues through research and development (R&D). One DOE-NE activity supporting this mission is the Light Water Reactor Sustainability (LWRS) program. LWRS has the overall objective to sustain the operation of existing commercial nuclear power plants (NPPs) through conducting R&D across multiple “pathways,” or R&D focus areas. The Advanced Instrumentation, Information, and Control (II&C) Systems Technologies pathway conducts targeted R&D to address aging and reliability concerns with the legacy instrumentation and control (I&C) and related information systemsmore » in operating U.S. NPPs. This work involves (1) ensuring that legacy analog II&C systems are not life-limiting issues for the LWR fleet, and (2) implementing digital II&C technology in a manner that enables broad innovation and business improvement in the NPP operating model. Under the LWRS Advanced II&C pathway, Human Factors experts at Idaho National Laboratory (INL) have been conducting R&D in support of NPP main control room (MCR) modernization activities. Work in prior years has focused on migrating analog I&C systems to new digital I&C systems (). In fiscal year 2016 (FY16), one new focus area for this research is migrating older digital I&C systems to new and advanced digital I&C systems. This report summarizes a plan for conducting a digital-to-digital migration of a legacy digital I&C system to a new digital I&C system in support of control room modernization activities.« less

Soft-Fault Detection Technologies Developed for Electrical Power Systems

NASA Technical Reports Server (NTRS)

Button, Robert M.

2004-01-01

The NASA Glenn Research Center, partner universities, and defense contractors are working to develop intelligent power management and distribution (PMAD) technologies for future spacecraft and launch vehicles. The goals are to provide higher performance (efficiency, transient response, and stability), higher fault tolerance, and higher reliability through the application of digital control and communication technologies. It is also expected that these technologies will eventually reduce the design, development, manufacturing, and integration costs for large, electrical power systems for space vehicles. The main focus of this research has been to incorporate digital control, communications, and intelligent algorithms into power electronic devices such as direct-current to direct-current (dc-dc) converters and protective switchgear. These technologies, in turn, will enable revolutionary changes in the way electrical power systems are designed, developed, configured, and integrated in aerospace vehicles and satellites. Initial successes in integrating modern, digital controllers have proven that transient response performance can be improved using advanced nonlinear control algorithms. One technology being developed includes the detection of "soft faults," those not typically covered by current systems in use today. Soft faults include arcing faults, corona discharge faults, and undetected leakage currents. Using digital control and advanced signal analysis algorithms, we have shown that it is possible to reliably detect arcing faults in high-voltage dc power distribution systems (see the preceding photograph). Another research effort has shown that low-level leakage faults and cable degradation can be detected by analyzing power system parameters over time. This additional fault detection capability will result in higher reliability for long-lived power systems such as reusable launch vehicles and space exploration missions.

77 FR 50724 - Developing Software Life Cycle Processes for Digital Computer Software Used in Safety Systems of...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-22

... NUCLEAR REGULATORY COMMISSION [NRC-2012-0195] Developing Software Life Cycle Processes for Digital... Software Life Cycle Processes for Digital Computer Software used in Safety Systems of Nuclear Power Plants... clarifications, the enhanced consensus practices for developing software life-cycle processes for digital...

Digital Flight Control System Redundancy Study

DTIC Science & Technology

1974-07-01

has its own separate power supr, y . d. Digital Processor The digital processor consists of the followdnq components: (1) Program Counter - This...1-3 Yaw Axis Control 108 1-4 Autothrottle (Airspeed Hold Mode) 109 1-5 Approach Power Compensation 110 1-6 Glideslope Flare 111 I-7 Glideslope Track...considsred to the extent that they imposed constraints on the candidate con- figurations. Cost, size, weight, power , maintainability, survivability and

Design of DSP-based high-power digital solar array simulator

NASA Astrophysics Data System (ADS)

Zhang, Yang; Liu, Zhilong; Tong, Weichao; Feng, Jian; Ji, Yibo

2013-12-01

To satisfy rigid performance specifications, a feedback control was presented for zoom optical lens plants. With the increasing of global energy consumption, research of the photovoltaic(PV) systems get more and more attention. Research of the digital high-power solar array simulator provides technical support for high-power grid-connected PV systems research.This paper introduces a design scheme of the high-power digital solar array simulator based on TMS320F28335. A DC-DC full-bridge topology was used in the system's main circuit. The switching frequency of IGBT is 25kHz.Maximum output voltage is 900V. Maximum output current is 20A. Simulator can be pre-stored solar panel IV curves.The curve is composed of 128 discrete points .When the system was running, the main circuit voltage and current values was feedback to the DSP by the voltage and current sensors in real-time. Through incremental PI,DSP control the simulator in the closed-loop control system. Experimental data show that Simulator output voltage and current follow a preset solar panels IV curve. In connection with the formation of high-power inverter, the system becomes gridconnected PV system. The inverter can find the simulator's maximum power point and the output power can be stabilized at the maximum power point (MPP).

A Nonlinear Digital Control Solution for a DC/DC Power Converter

NASA Technical Reports Server (NTRS)

Zhu, Minshao

2002-01-01

A digital Nonlinear Proportional-Integral-Derivative (NPID) control algorithm was proposed to control a 1-kW, PWM, DC/DC, switching power converter. The NPID methodology is introduced and a practical hardware control solution is obtained. The design of the controller was completed using Matlab (trademark) Simulink, while the hardware-in-the-loop testing was performed using both the dSPACE (trademark) rapid prototyping system, and a stand-alone Texas Instruments (trademark) Digital Signal Processor (DSP)-based system. The final Nonlinear digital control algorithm was implemented and tested using the ED408043-1 Westinghouse DC-DC switching power converter. The NPID test results are discussed and compared to the results of a standard Proportional-Integral (PI) controller.

Low Power Computing in Distributed Systems

DTIC Science & Technology

2006-04-01

performance applications. It has been adopted in embedded systems such as the Stargate from Crossbow [15] and the PASTA 4 0 0.1 0.2 0.3 0.4 (A) flo at...current consumption of the Stargate board is measured by an Agilent digital multimeter 34401A. The digital multimeter is connected with the PC for data...floating point operation vs. integer operation Power supply Digital multimeter Stargate board with Xscale processor 5 2.2 Library math function vs

47 CFR 74.795 - Digital low power TV and TV translator transmission system facilities.

Code of Federal Regulations, 2010 CFR

2010-10-01

... (CONTINUED) BROADCAST RADIO SERVICES EXPERIMENTAL RADIO, AUXILIARY, SPECIAL BROADCAST AND OTHER PROGRAM... transmitter shall be designed to produce digital television signals that can be satisfactorily viewed on...., average power over a 6 MHz channel) and shall be designed to prevent the power output from exceeding the...

47 CFR 74.795 - Digital low power TV and TV translator transmission system facilities.

Code of Federal Regulations, 2013 CFR

2013-10-01

... (CONTINUED) BROADCAST RADIO SERVICES EXPERIMENTAL RADIO, AUXILIARY, SPECIAL BROADCAST AND OTHER PROGRAM... transmitter shall be designed to produce digital television signals that can be satisfactorily viewed on...., average power over a 6 MHz channel) and shall be designed to prevent the power output from exceeding the...

47 CFR 74.795 - Digital low power TV and TV translator transmission system facilities.

Code of Federal Regulations, 2012 CFR

2012-10-01

... (CONTINUED) BROADCAST RADIO SERVICES EXPERIMENTAL RADIO, AUXILIARY, SPECIAL BROADCAST AND OTHER PROGRAM... transmitter shall be designed to produce digital television signals that can be satisfactorily viewed on...., average power over a 6 MHz channel) and shall be designed to prevent the power output from exceeding the...

47 CFR 74.795 - Digital low power TV and TV translator transmission system facilities.

Code of Federal Regulations, 2011 CFR

2011-10-01

... (CONTINUED) BROADCAST RADIO SERVICES EXPERIMENTAL RADIO, AUXILIARY, SPECIAL BROADCAST AND OTHER PROGRAM... transmitter shall be designed to produce digital television signals that can be satisfactorily viewed on...., average power over a 6 MHz channel) and shall be designed to prevent the power output from exceeding the...

47 CFR 74.795 - Digital low power TV and TV translator transmission system facilities.

Code of Federal Regulations, 2014 CFR

2014-10-01

... (CONTINUED) BROADCAST RADIO SERVICES EXPERIMENTAL RADIO, AUXILIARY, SPECIAL BROADCAST AND OTHER PROGRAM... transmitter shall be designed to produce digital television signals that can be satisfactorily viewed on...., average power over a 6 MHz channel) and shall be designed to prevent the power output from exceeding the...

Portable Power And Digital-Communication Units

NASA Technical Reports Server (NTRS)

Levin, Richard R.; Henry, Paul K.; Rosenberg, Leigh S.

1992-01-01

Conceptual network of electronic-equipment modules provides electrical power and digital radio communications at multiple sites not served by cables. System includes central communication unit and portable units powered by solar photovoltaic arrays. Useful to serve equipment that must be set up quickly at remote sites or buildings that cannot be modified to provide cable connections.

Integrated digital/electric aircraft concepts study

NASA Technical Reports Server (NTRS)

Cronin, M. J.; Hays, A. P.; Green, F. B.; Radovcich, N. A.; Helsley, C. W.; Rutchik, W. L.

1985-01-01

The integrated digital/electrical aircraft (IDEA) is an aircraft concept which employs all electric secondary power systems and advanced digital flight control systems. After trade analysis, preferred systems were applied to the baseline configuration. An additional configuration, the alternate IDEA, was also considered. For this concept the design ground rules were relaxed in order to quantify additional synergistic benefits. It was proposed that an IDEA configuration and technical risks associated with the IDEA systems concepts be defined and the research and development required activities to reduce these risks be identified. The selected subsystems include: power generation, power distribution, actuators, environmental control system and flight controls systems. When the aircraft was resized, block fuel was predicted to decrease by 11.3 percent, with 7.9 percent decrease in direct operating cost. The alternate IDEA shows a further 3.4 percent reduction in block fuel and 3.1 percent reduction in direct operating cost.

The Design of the Digital Multiplexer based on Power Carrier Communication on Sports Venues

NASA Astrophysics Data System (ADS)

Lu, Ming-jing; Liang, Li; Yu, Xiao-yan

In this paper, one kind of double CPU, the low power loss, the low cost digital multiplexer has been designed in conducted the full research to this communicated way, which is satisfied the need of the electric power correspondence transmission system, especially in sports venues. This article is elaborated the digital multiplexer's hardware and the software principle of design in detail, carries on the simulation using the monolithic integrated circuit simulator, has achieved the satisfactory effect through the debug.

Development of Shunt-Type Three-Phase Active Power Filter with Novel Adaptive Control for Wind Generators

PubMed Central

2015-01-01

This paper proposes a new adaptive filter for wind generators that combines instantaneous reactive power compensation technology and current prediction controller, and therefore this system is characterized by low harmonic distortion, high power factor, and small DC-link voltage variations during load disturbances. The performance of the system was first simulated using MATLAB/Simulink, and the possibility of an adaptive digital low-pass filter eliminating current harmonics was confirmed in steady and transient states. Subsequently, a digital signal processor was used to implement an active power filter. The experimental results indicate, that for the rated operation of 2 kVA, the system has a total harmonic distortion of current less than 5.0% and a power factor of 1.0 on the utility side. Thus, the transient performance of the adaptive filter is superior to the traditional digital low-pass filter and is more economical because of its short computation time compared with other types of adaptive filters. PMID:26451391

Development of Shunt-Type Three-Phase Active Power Filter with Novel Adaptive Control for Wind Generators.

PubMed

Chen, Ming-Hung

2015-01-01

This paper proposes a new adaptive filter for wind generators that combines instantaneous reactive power compensation technology and current prediction controller, and therefore this system is characterized by low harmonic distortion, high power factor, and small DC-link voltage variations during load disturbances. The performance of the system was first simulated using MATLAB/Simulink, and the possibility of an adaptive digital low-pass filter eliminating current harmonics was confirmed in steady and transient states. Subsequently, a digital signal processor was used to implement an active power filter. The experimental results indicate, that for the rated operation of 2 kVA, the system has a total harmonic distortion of current less than 5.0% and a power factor of 1.0 on the utility side. Thus, the transient performance of the adaptive filter is superior to the traditional digital low-pass filter and is more economical because of its short computation time compared with other types of adaptive filters.

Digital computer study of nuclear reactor thermal transients during startup of 60-kWe Brayton power conversion system

NASA Technical Reports Server (NTRS)

Jefferies, K. S.; Tew, R. C.

1974-01-01

A digital computer study was made of reactor thermal transients during startup of the Brayton power conversion loop of a 60-kWe reactor Brayton power system. A startup procedure requiring the least Brayton system complication was tried first; this procedure caused violations of design limits on key reactor variables. Several modifications of this procedure were then found which caused no design limit violations. These modifications involved: (1) using a slower rate of increase in gas flow; (2) increasing the initial reactor power level to make the reactor respond faster; and (3) appropriate reactor control drum manipulation during the startup transient.

77 FR 50723 - Verification, Validation, Reviews, and Audits for Digital Computer Software Used in Safety...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-22

... Digital Computer Software Used in Safety Systems of Nuclear Power Plants AGENCY: Nuclear Regulatory..., ``Verification, Validation, Reviews, and Audits for Digital Computer Software used in Safety Systems of Nuclear... NRC regulations promoting the development of, and compliance with, software verification and...

77 FR 50720 - Test Documentation for Digital Computer Software Used in Safety Systems of Nuclear Power Plants

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-22

... NUCLEAR REGULATORY COMMISSION [NRC-2012-0195] Test Documentation for Digital Computer Software...) is issuing for public comment draft regulatory guide (DG), DG-1207, ``Test Documentation for Digital... practices for test documentation for software and computer systems as described in the Institute of...

Advanced power analysis methodology targeted to the optimization of a digital pixel readout chip design and its critical serial powering system

NASA Astrophysics Data System (ADS)

Marconi, S.; Orfanelli, S.; Karagounis, M.; Hemperek, T.; Christiansen, J.; Placidi, P.

2017-02-01

A dedicated power analysis methodology, based on modern digital design tools and integrated with the VEPIX53 simulation framework developed within RD53 collaboration, is being used to guide vital choices for the design and optimization of the next generation ATLAS and CMS pixel chips and their critical serial powering circuit (shunt-LDO). Power consumption is studied at different stages of the design flow under different operating conditions. Significant effort is put into extensive investigations of dynamic power variations in relation with the decoupling seen by the powering network. Shunt-LDO simulations are also reported to prove the reliability at the system level.

A digital computer simulation and study of a direct-energy-transfer power-conditioning system

NASA Technical Reports Server (NTRS)

Burns, W. W., III; Owen, H. A., Jr.; Wilson, T. G.; Rodriguez, G. E.; Paulkovich, J.

1975-01-01

An investigation of the behavior of the power-conditioning system as a whole is a necessity to ensure the integrity of the aggregate system in the case of space applications. An approach for conducting such an investigation is considered. A description is given of the application of a general digital analog simulator program to the study of an aggregate power-conditioning system which is being developed for use on the International Ultraviolet Explorer spacecraft. The function of the direct energy transfer system studied involves a coupling of a solar array through a main distribution bus to the spacecraft electrical loads.

An accuracy aware low power wireless EEG unit with information content based adaptive data compression.

PubMed

Tolbert, Jeremy R; Kabali, Pratik; Brar, Simeranjit; Mukhopadhyay, Saibal

2009-01-01

We present a digital system for adaptive data compression for low power wireless transmission of Electroencephalography (EEG) data. The proposed system acts as a base-band processor between the EEG analog-to-digital front-end and RF transceiver. It performs a real-time accuracy energy trade-off for multi-channel EEG signal transmission by controlling the volume of transmitted data. We propose a multi-core digital signal processor for on-chip processing of EEG signals, to detect signal information of each channel and perform real-time adaptive compression. Our analysis shows that the proposed approach can provide significant savings in transmitter power with minimal impact on the overall signal accuracy.

Low-power wireless ECG acquisition and classification system for body sensor networks.

PubMed

Lee, Shuenn-Yuh; Hong, Jia-Hua; Hsieh, Cheng-Han; Liang, Ming-Chun; Chang Chien, Shih-Yu; Lin, Kuang-Hao

2015-01-01

A low-power biosignal acquisition and classification system for body sensor networks is proposed. The proposed system consists of three main parts: 1) a high-pass sigma delta modulator-based biosignal processor (BSP) for signal acquisition and digitization, 2) a low-power, super-regenerative on-off keying transceiver for short-range wireless transmission, and 3) a digital signal processor (DSP) for electrocardiogram (ECG) classification. The BSP and transmitter circuits, which are the body-end circuits, can be operated for over 80 days using two 605 mAH zinc-air batteries as the power supply; the power consumption is 586.5 μW. As for the radio frequency receiver and DSP, which are the receiving-end circuits that can be integrated in smartphones or personal computers, power consumption is less than 1 mW. With a wavelet transform-based digital signal processing circuit and a diagnosis control by cardiologists, the accuracy of beat detection and ECG classification are close to 99.44% and 97.25%, respectively. All chips are fabricated in TSMC 0.18-μm standard CMOS process.

Integrating the ECG power-line interference removal methods with rule-based system.

PubMed

Kumaravel, N; Senthil, A; Sridhar, K S; Nithiyanandam, N

1995-01-01

The power-line frequency interference in electrocardiographic signals is eliminated to enhance the signal characteristics for diagnosis. The power-line frequency normally varies +/- 1.5 Hz from its standard value of 50 Hz. In the present work, the performances of the linear FIR filter, Wave digital filter (WDF) and adaptive filter for the power-line frequency variations from 48.5 to 51.5 Hz in steps of 0.5 Hz are studied. The advantage of the LMS adaptive filter in the removal of power-line frequency interference even if the frequency of interference varies by +/- 1.5 Hz from its normal value of 50 Hz over other fixed frequency filters is very well justified. A novel method of integrating rule-based system approach with linear FIR filter and also with Wave digital filter are proposed. The performances of Rule-based FIR filter and Rule-based Wave digital filter are compared with the LMS adaptive filter.

A digital intensity stabilization system for HeNe laser

NASA Astrophysics Data System (ADS)

Wei, Zhimeng; Lu, Guangfeng; Yang, Kaiyong; Long, Xingwu; Huang, Yun

2012-02-01

A digital intensity stabilization system for HeNe laser is developed. Based on a switching power IC to design laser power supply and a general purpose microcontroller to realize digital PID control, the system constructs a closed loop to stabilize the laser intensity by regulating its discharge current. The laser tube is made of glass ceramics and its integrated structure is steady enough to eliminate intensity fluctuations at high frequency and attenuates all intensity fluctuations, and this makes it easy to tune the control loop. The control loop between discharge current and photodiode voltage eliminates the long-term drifts. The intensity stability of the HeNe laser with this system is 0.014% over 12 h.

Digital control for the condensate system in a combined cycle power plant

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

Sanchez Parra, M.; Fuentes Gutierrez, J.E.; Castelo Cuevas, L.

1994-12-31

This paper presents the highlights by means of which development, installation and start up of the digital control system (DCS)for the condenser and hotwell (condensate system) were performed. This system belongs to the distributed control system installed by the Instituto de Investigaciones Electricas (IIE) at the Combined Cycle Power Plant in Gomez Palacio (GP), Durango, Mexico, during the February-March period, in 1993. The main steps for development of the condenser and hotwell control system include: process modeling, definition of control strategies, algorithms, design and software development, PC simulation tests, laboratory tests with an equipment similar to the one installed atmore » the GP Power Plant, installation, and finally, start up, which was a joint effort with the GP Power Plant engineering staff.« less

Bounds on the performance of a class of digital communication systems

NASA Technical Reports Server (NTRS)

Polk, D. R.; Gupta, S. C.; Cohn, D. L.

1973-01-01

Bounds on the capacity of a class of digital communication channels are derived. Equating the bounds on capacity to rate-distortion functions of (typical) sources in turn produces bounds on the performance of a class of digital communication systems. For ratios of squared quantization level to noise variance much less than one, the power requirements for this class of digital communication systems are shown to be within approximately 3 dB of the theoretical optimum.

Low-power triggered data acquisition system and method

NASA Technical Reports Server (NTRS)

Champaigne, Kevin (Inventor); Sumners, Jonathan (Inventor)

2012-01-01

A low-power triggered data acquisition system and method utilizes low-powered circuitry, comparators, and digital logic incorporated into a miniaturized device interfaced with self-generating transducer sensor inputs to detect, identify and assess impact and damage to surfaces and structures wherein, upon the occurrence of a triggering event that produces a signal greater than a set threshold changes the comparator output and causes the system to acquire and store digital data representative of the incoming waveform on at least one triggered channel. The sensors may be disposed in an array to provide triangulation and location of the impact.

Field Programmable Gate Array for Implementation of Redundant Advanced Digital Feedback Control

NASA Technical Reports Server (NTRS)

King, K. D.

2003-01-01

The goal of this effort was to develop a digital motor controller using field programmable gate arrays (FPGAs). This is a more rugged approach than a conventional microprocessor digital controller. FPGAs typically have higher radiation (rad) tolerance than both the microprocessor and memory required for a conventional digital controller. Furthermore, FPGAs can typically operate at higher speeds. (While speed is usually not an issue for motor controllers, it can be for other system controllers.) Other than motor power, only a 3.3-V digital power supply was used in the controller; no analog bias supplies were used. Since most of the circuit was implemented in the FPGA, no additional parts were needed other than the power transistors to drive the motor. The benefits that FPGAs provide over conventional designs-lower power and fewer parts-allow for smaller packaging and reduced weight and cost.

Modems for emerging digital cellular-mobile radio system

NASA Technical Reports Server (NTRS)

Feher, Kamilo

1991-01-01

Digital modem techniques for emerging digital cellular telecommunications-mobile radio system applications are described and analyzed. In particular, theoretical performance, experimental results, principles of operation, and various architectures of pi/4-QPSK (pi/4-shifted coherent or differential QPSK) modems for second-generation US digital cellular radio system applications are presented. The spectral/power efficiency and performance of the pi/4-QPSK modems (American and Japanese digital cellular emerging standards) are studied and briefly compared to GMSK (Gaussian minimum-shift keying) modems (proposed for European DECT and GSM cellular standards). Improved filtering strategies and digital pilot-aided (digital channel sounding) techniques are also considered for pi/4-QPSK and other digital modems. These techniques could significantly improve the performance of digital cellular and other digital land mobile and satellite mobile radio systems. More spectrally efficient modem trends for future cellular/mobile (land mobile) and satellite communication systems applications are also highlighted.

Ubiquitous Presenter: A Tablet PC-based System to Support Instructors and Students

NASA Astrophysics Data System (ADS)

Price, Edward; Simon, Beth

2009-12-01

Digital lecturing systems (computer and projector, often with PowerPoint) offer physics instructors the ability to incorporate graphics and the power to share and reuse materials. But these systems do a poor job of supporting interaction in the classroom. For instance, with digital presentation systems, instructors have limited ability to spontaneously respond to student questions. This limitation is especially acute during classroom activities such as problem solving, Peer Instruction, and Interactive Lecture Demonstrations (ILDs).2 A Tablet PC, a laptop computer with a stylus that can be used to "write" on the screen, provides a way for instructors to add digital ink spontaneously to a presentation in progress. The Tablet PC can be a powerful tool for teaching,3,4 especially when combined with software systems specifically designed to leverage digital ink for pedagogical uses. Ubiquitous Presenter (UP) is one such freely available system.5 Developed at the University of California, San Diego, and based on Classroom Presenter,6 UP allows the instructor to ink prepared digital material (such as exported PowerPoint slides) in real time in class. Ink is automatically archived stroke by stroke and can be reviewed through a web browser (by both students and instructors). The system also supports spontaneous in-class interaction through a web interface—students with web-enabled devices (Tablet PCs, regular laptops, PDAs, and cell phones) can make text-, ink-, or image-based submissions on the instructor's slides. The instructor can review and then project submitted slides to the class and add additional ink, so that material generated by students can be a focus for discussion. A brief video showing UP in action is at http://physics.csusm.edu/UP. In this article, we describe UP and give examples of how UP can support the physics classroom.

Signal-to-noise ratio estimation in digital computer simulation of lowpass and bandpass systems with applications to analog and digital communications, volume 3

NASA Technical Reports Server (NTRS)

Tranter, W. H.; Turner, M. D.

1977-01-01

Techniques are developed to estimate power gain, delay, signal-to-noise ratio, and mean square error in digital computer simulations of lowpass and bandpass systems. The techniques are applied to analog and digital communications. The signal-to-noise ratio estimates are shown to be maximum likelihood estimates in additive white Gaussian noise. The methods are seen to be especially useful for digital communication systems where the mapping from the signal-to-noise ratio to the error probability can be obtained. Simulation results show the techniques developed to be accurate and quite versatile in evaluating the performance of many systems through digital computer simulation.

Development of Boolean calculus and its applications. [digital systems design

NASA Technical Reports Server (NTRS)

Tapia, M. A.

1980-01-01

The development of Boolean calculus for its application to developing digital system design methodologies that would reduce system complexity, size, cost, speed, power requirements, etc., is discussed. Synthesis procedures for logic circuits are examined particularly asynchronous circuits using clock triggered flip flops.

2017 Guralp Affinity Digitizer Evaluation.

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

Merchant, Bion J.

Sandia National Laboratories has tested and evaluated two Guralp Affinity digitizers. The Affinity digitizers are intended to record sensor output for seismic and infrasound monitoring applications. The purpose of this digitizer evaluation is to measure the performance characteristics in such areas as power consumption, input impedance, sensitivity, full scale, self- noise, dynamic range, system noise, response, passband, and timing. The Affinity digitizers are being evaluated for potential use in the International Monitoring System (IMS) of the Comprehensive Nuclear Test-Ban-Treaty Organization (CTBTO).

SCANIT: centralized digitizing of forest resource maps or photographs

Treesearch

Elliot L. Amidon; E. Joyce Dye

1981-01-01

Spatial data on wildland resource maps and aerial photographs can be analyzed by computer after digitizing. SCANIT is a computerized system for encoding such data in digital form. The system, consisting of a collection of computer programs and subroutines, provides a powerful and versatile tool for a variety of resource analyses. SCANIT also may be converted easily to...

Power system analysis of Hanlim superconducting HVDC system using real time digital simulator

NASA Astrophysics Data System (ADS)

Won, Y. J.; Kim, J. G.; Kim, A. R.; Kim, G. H.; Park, M.; Yu, I. K.; Sim, K. D.; Cho, J.; Lee, S.; Jeong, K. W.; Watanabe, K.

2011-11-01

Jeju island is located approximately 100 km south from the mainland of Korea, and had a peak load of about 553 MW in 2008. The demand increases 7.2% a year over the last 5 years. Since the wind profiles of Jeju island are more favorable than mainland of Korea, many companies have shown interest in the wind power business at the Jeju island. Moreover KEPCO has a plan for renewable energy test too whose power will be delivered by HVDC system. One kilometer length of total 8 km was designed as superconducting DC cable. Rest 7 km will be the conventional overhead line. In this paper, the authors have developed a simulation model of the power network around 8 km HVDC system using real time digital simulator (RTDS).

A Cyber Security Self-Assessment Method for Nuclear Power Plants

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

Glantz, Clifford S.; Coles, Garill A.; Bass, Robert B.

2004-11-01

A cyber security self-assessment method (the Method) has been developed by Pacific Northwest National Laboratory. The development of the Method was sponsored and directed by the U.S. Nuclear Regulatory Commission. Members of the Nuclear Energy Institute Cyber Security Task Force also played a substantial role in developing the Method. The Method's structured approach guides nuclear power plants in scrutinizing their digital systems, assessing the potential consequences to the plant of a cyber exploitation, identifying vulnerabilities, estimating cyber security risks, and adopting cost-effective protective measures. The focus of the Method is on critical digital assets. A critical digital asset is amore » digital device or system that plays a role in the operation, maintenance, or proper functioning of a critical system (i.e., a plant system that can impact safety, security, or emergency preparedness). A critical digital asset may have a direct or indirect connection to a critical system. Direct connections include both wired and wireless communication pathways. Indirect connections include sneaker-net pathways by which software or data are manually transferred from one digital device to another. An indirect connection also may involve the use of instructions or data stored on a critical digital asset to make adjustments to a critical system. The cyber security self-assessment begins with the formation of an assessment team, and is followed by a six-stage process.« less

A low-power small-area ADC array for IRFPA readout

NASA Astrophysics Data System (ADS)

Zhong, Shengyou; Yao, Libin

2013-09-01

The readout integrated circuit (ROIC) is a bridge between the infrared focal plane array (IRFPA) and image processing circuit in an infrared imaging system. The ROIC is the first part of signal processing circuit and connected to detectors directly, so its performance will greatly affect the detector or even the whole imaging system performance. With the development of CMOS technologies, it's possible to digitalize the signal inside the ROIC and develop the digital ROIC. Digital ROIC can reduce complexity of the whole system and improve the system reliability. More importantly, it can accommodate variety of digital signal processing techniques which the traditional analog ROIC cannot achieve. The analog to digital converter (ADC) is the most important building block in the digital ROIC. The requirements for ADCs inside the ROIC are low power, high dynamic range and small area. In this paper we propose an RC hybrid Successive Approximation Register (SAR) ADC as the column ADC for digital ROIC. In our proposed ADC structure, a resistor ladder is used to generate several voltages. The proposed RC hybrid structure not only reduces the area of capacitor array but also releases requirement for capacitor array matching. Theory analysis and simulation show RC hybrid SAR ADC is suitable for ADC array applications

Multi-aperture digital coherent combining for free-space optical communication receivers.

PubMed

Geisler, David J; Yarnall, Timothy M; Stevens, Mark L; Schieler, Curt M; Robinson, Bryan S; Hamilton, Scott A

2016-06-13

Space-to-ground optical communication systems can benefit from reducing the size, weight, and power profiles of space terminals. One way of reducing the required power-aperture product on a space platform is to implement effective, but costly, single-aperture ground terminals with large collection areas. In contrast, we present a ground terminal receiver architecture in which many small less-expensive apertures are efficiently combined to create a large effective aperture while maintaining excellent receiver sensitivity. This is accomplished via coherent detection behind each aperture followed by digitization. The digitized signals are then combined in a digital signal processing chain. Experimental results demonstrate lossless coherent combining of four lasercom signals, at power levels below 0.1 photons/bit/aperture.

Electronic polarization-division demultiplexing based on digital signal processing in intensity-modulation direct-detection optical communication systems.

PubMed

Kikuchi, Kazuro

2014-01-27

We propose a novel configuration of optical receivers for intensity-modulation direct-detection (IM · DD) systems, which can cope with dual-polarization (DP) optical signals electrically. Using a Stokes analyzer and a newly-developed digital signal-processing (DSP) algorithm, we can achieve polarization tracking and demultiplexing in the digital domain after direct detection. Simulation results show that the power penalty stemming from digital polarization manipulations is negligibly small.

Millimeter Wave Communications Program: Link Tests of High Speed Digital Radio Set AN/GRC-173 (XW-1)

DTIC Science & Technology

1975-01-01

Terrence Kelly, John Mutty, Edward Rich, James Roche, William J. Smxth, Carson Tsao, and David Trask. Hugh N. Siegel (DCCW) was the RADC...shelter, except for the parabolic dish and front-feed antenna system, which is mast-mounted adjacent to the shelter and connected to an rf input...Equipment: All rf and digital units 8. POWER SUPPLIES Quantity: 1 for rf , 1 for digital Primary Power: 120/240V +10% single phase, 47 - 420 Hz

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.

Multichannel Phase and Power Detector

NASA Technical Reports Server (NTRS)

Li, Samuel; Lux, James; McMaster, Robert; Boas, Amy

2006-01-01

An electronic signal-processing system determines the phases of input signals arriving in multiple channels, relative to the phase of a reference signal with which the input signals are known to be coherent in both phase and frequency. The system also gives an estimate of the power levels of the input signals. A prototype of the system has four input channels that handle signals at a frequency of 9.5 MHz, but the basic principles of design and operation are extensible to other signal frequencies and greater numbers of channels. The prototype system consists mostly of three parts: An analog-to-digital-converter (ADC) board, which coherently digitizes the input signals in synchronism with the reference signal and performs some simple processing; A digital signal processor (DSP) in the form of a field-programmable gate array (FPGA) board, which performs most of the phase- and power-measurement computations on the digital samples generated by the ADC board; and A carrier board, which allows a personal computer to retrieve the phase and power data. The DSP contains four independent phase-only tracking loops, each of which tracks the phase of one of the preprocessed input signals relative to that of the reference signal (see figure). The phase values computed by these loops are averaged over intervals, the length of which is chosen to obtain output from the DSP at a desired rate. In addition, a simple sum of squares is computed for each channel as an estimate of the power of the signal in that channel. The relative phases and the power level estimates computed by the DSP could be used for diverse purposes in different settings. For example, if the input signals come from different elements of a phased-array antenna, the phases could be used as indications of the direction of arrival of a received signal and/or as feedback for electronic or mechanical beam steering. The power levels could be used as feedback for automatic gain control in preprocessing of incoming signals. For another example, the system could be used to measure the phases and power levels of outputs of multiple power amplifiers to enable adjustment of the amplifiers for optimal power combining.

Digital avionics systems - Principles and practices (2nd revised and enlarged edition)

NASA Technical Reports Server (NTRS)

Spitzer, Cary R.

1993-01-01

The state of the art in digital avionics systems is surveyed. The general topics addressed include: establishing avionics system requirements; avionics systems essentials in data bases, crew interfaces, and power; fault tolerance, maintainability, and reliability; architectures; packaging and fitting the system into the aircraft; hardware assessment and validation; software design, assessment, and validation; determining the costs of avionics.

Method and system for conserving power in a telecommunications network during emergency situations

DOEpatents

Conrad, Stephen H [Algodones, NM; O'Reilly, Gerard P [Manalapan, NJ

2011-10-11

Disclosed is a method and apparatus for conserving power in a telecommunications network during emergency situations. A permissible number list of emergency and/or priority numbers is stored in the telecommunications network. In the event of an emergency or power failure, input digits of a call to the telecommunications network are compared to the permissible number list. The call is processed in the telecommunications network and routed to its destination if the input digits match an entry in the permissible number list. The call is dropped without any further processing if the input digits do not match an entry in the permissible number list. Thus, power can be conserved in emergency situations by only allowing emergency and/or priority calls.

A Ratiometric Method for Johnson Noise Thermometry Using a Quantized Voltage Noise Source

NASA Astrophysics Data System (ADS)

Nam, S. W.; Benz, S. P.; Martinis, J. M.; Dresselhaus, P.; Tew, W. L.; White, D. R.

2003-09-01

Johnson Noise Thermometry (JNT) involves the measurement of the statistical variance of a fluctuating voltage across a resistor in thermal equilibrium. Modern digital techniques make it now possible to perform many functions required for JNT in highly efficient and predictable ways. We describe the operational characteristics of a prototype JNT system which uses digital signal processing for filtering, real-time spectral cross-correlation for noise power measurement, and a digitally synthesized Quantized Voltage Noise Source (QVNS) as an AC voltage reference. The QVNS emulates noise with a constant spectral density that is stable, programmable, and calculable in terms of known parameters using digital synthesis techniques. Changes in analog gain are accounted for by alternating the inputs between the Johnson noise sensor and the QVNS. The Johnson noise power at a known temperature is first balanced with a synthesized noise power from the QVNS. The process is then repeated by balancing the noise power from the same resistor at an unknown temperature. When the two noise power ratios are combined, a thermodynamic temperature is derived using the ratio of the two QVNS spectral densities. We present preliminary results where the ratio between the gallium triple point and the water triple point is used to demonstrate the accuracy of the measurement system with a standard uncertainty of 0.04 %.

Design of digital voice storage and playback system

NASA Astrophysics Data System (ADS)

Tang, Chao

2018-03-01

Based on STC89C52 chip, this paper presents a single chip microcomputer minimum system, which is used to realize the logic control of digital speech storage and playback system. Compared with the traditional tape voice recording system, the system has advantages of small size, low power consumption, The effective solution of traditional voice recording system is limited in the use of electronic and information processing.

A PWM Buck Converter With Load-Adaptive Power Transistor Scaling Scheme Using Analog-Digital Hybrid Control for High Energy Efficiency in Implantable Biomedical Systems.

PubMed

Park, Sung-Yun; Cho, Jihyun; Lee, Kyuseok; Yoon, Euisik

2015-12-01

We report a pulse width modulation (PWM) buck converter that is able to achieve a power conversion efficiency (PCE) of > 80% in light loads 100 μA) for implantable biomedical systems. In order to achieve a high PCE for the given light loads, the buck converter adaptively reconfigures the size of power PMOS and NMOS transistors and their gate drivers in accordance with load currents, while operating at a fixed frequency of 1 MHz. The buck converter employs the analog-digital hybrid control scheme for coarse/fine adjustment of power transistors. The coarse digital control generates an approximate duty cycle necessary for driving a given load and selects an appropriate width of power transistors to minimize redundant power dissipation. The fine analog control provides the final tuning of the duty cycle to compensate for the error from the coarse digital control. The mode switching between the analog and digital controls is accomplished by a mode arbiter which estimates the average of duty cycles for the given load condition from limit cycle oscillations (LCO) induced by coarse adjustment. The fabricated buck converter achieved a peak efficiency of 86.3% at 1.4 mA and > 80% efficiency for a wide range of load conditions from 45 μA to 4.1 mA, while generating 1 V output from 2.5-3.3 V supply. The converter occupies 0.375 mm(2) in 0.18 μm CMOS processes and requires two external components: 1.2 μF capacitor and 6.8 μH inductor.

Nuclear power plant digital system PRA pilot study with the dynamic flow-graph methodology

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

Yau, M.; Motamed, M.; Guarro, S.

2006-07-01

Current Probabilistic Risk Assessment (PRA) methodology is well established in analyzing hardware and some of the key human interactions. However processes for analyzing the software functions of digital systems within a plant PRA framework, and accounting for the digital system contribution to the overall risk are not generally available nor are they well understood and established. A recent study reviewed a number of methodologies that have potential applicability to modeling and analyzing digital systems within a PRA framework. This study identified the Dynamic Flow-graph Methodology (DFM) and the Markov Methodology as the most promising tools. As a result of thismore » study, a task was defined under the framework of a collaborative agreement between the U.S. Nuclear Regulatory Commission (NRC) and the Ohio State Univ. (OSU). The objective of this task is to set up benchmark systems representative of digital systems used in nuclear power plants and to evaluate DFM and the Markov methodology with these benchmark systems. The first benchmark system is a typical Pressurized Water Reactor (PWR) Steam Generator (SG) Feedwater System (FWS) level control system based on an earlier ASCA work with the U.S. NRC 2, upgraded with modern control laws. ASCA, Inc. is currently under contract to OSU to apply DFM to this benchmark system. The goal is to investigate the feasibility of using DFM to analyze and quantify digital system risk, and to integrate the DFM analytical results back into the plant event tree/fault tree PRA model. (authors)« less

How Digital Scaffolds in Games Direct Problem-Solving Behaviors

ERIC Educational Resources Information Center

Sun, Chuen-Tsai; Wang, Dai-Yi; Chan, Hui-Ling

2011-01-01

Digital systems offer computational power and instant feedback. Game designers are using these features to create scaffolding tools to reduce player frustration. However, researchers are finding some unexpected effects of scaffolding on strategy development and problem-solving behaviors. We used a digital Sudoku game named "Professor Sudoku" to…

47 CFR 73.6019 - Digital Class A TV station protection of low power TV, TV translator, digital low power TV and...

Code of Federal Regulations, 2010 CFR

2010-10-01

... power TV, TV translator, digital low power TV and digital TV translator stations. 73.6019 Section 73... low power TV, TV translator, digital low power TV and digital TV translator stations. An application... A TV station will not be accepted if it fails to protect authorized low power TV, TV translator...

A 32-channel fully implantable wireless neurosensor for simultaneous recording from two cortical regions.

PubMed

Aceros, Juan; Yin, Ming; Borton, David A; Patterson, William R; Nurmikko, Arto V

2011-01-01

We present a fully implantable, wireless, neurosensor for multiple-location neural interface applications. The device integrates two independent 16-channel intracortical microelectrode arrays and can simultaneously acquire 32 channels of broadband neural data from two separate cortical areas. The system-on-chip implantable sensor is built on a flexible Kapton polymer substrate and incorporates three very low power subunits: two cortical subunits connected to a common subcutaneous subunit. Each cortical subunit has an ultra-low power 16-channel preamplifier and multiplexer integrated onto a cortical microelectrode array. The subcutaneous epicranial unit has an inductively coupled power supply, two analog-to-digital converters, a low power digital controller chip, and microlaser-based infrared telemetry. The entire system is soft encapsulated with biocompatible flexible materials for in vivo applications. Broadband neural data is conditioned, amplified, and analog multiplexed by each of the cortical subunits and passed to the subcutaneous component, where it is digitized and combined with synchronization data and wirelessly transmitted transcutaneously using high speed infrared telemetry.

Anomalous TWTA output power spikes and their effect on a digital satellite communications system

NASA Technical Reports Server (NTRS)

May, Brian D.; Kerczewski, Robert J.; Svoboda, James S.

1992-01-01

Several 30 GHz, 60 W traveling wave tube amplifiers (TWTA) were manufactured for the NASA Lewis Research Center's High Burst Rate Link Evaluation Terminal Project. An unusual operating problem characterized by anomalous nonperiodic output power spikes, common to all of the TWTAs proved during testing to significantly affect the performance of a digitally-modulated data transmission test system. Modifications made to the TWTAs significantly curtailed the problem and allowed acceptable system performance to be obtained. This paper presents a discussion of the TWTA output power spike problem, possible causes of the problem, and the solutions implemented by the manufacturer which improved the TWTA performance to an acceptable level. The results of the testing done at NASA Lewis on the TWTAs both before and after the improvement made by Hughes are presented, and the effects of the output power spikes on the performance of the test system are discussed.

78 FR 47015 - Software Requirement Specifications for Digital Computer Software Used in Safety Systems of...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-02

... NUCLEAR REGULATORY COMMISSION [NRC-2012-0195] Software Requirement Specifications for Digital Computer Software Used in Safety Systems of Nuclear Power Plants AGENCY: Nuclear Regulatory Commission... issuing a revised regulatory guide (RG), revision 1 of RG 1.172, ``Software Requirement Specifications for...

Generation of multiple analog pulses with different duty cycles within VME control system for ICRH Aditya system

NASA Astrophysics Data System (ADS)

Joshi, Ramesh; Singh, Manoj; Jadav, H. M.; Misra, Kishor; Kulkarni, S. V.; ICRH-RF Group

2010-02-01

Ion Cyclotron Resonance Heating (ICRH) is a promising heating method for a fusion device due to its localized power deposition profile, a direct ion heating at high density, and established technology for high RF power generation and transmission at low cost. Multiple analog pulse with different duty cycle in master of digital pulse for Data acquisition and Control system for steady state RF ICRH System(RF ICRH DAC) to be used for operating of RF Generator in Aditya to produce pre ionization and second analog pulse will produce heating. The control system software is based upon single digital pulse operation for RF source. It is planned to integrate multiple analog pulses with different duty cycle in master of digital pulse for Data acquisition and Control system for RF ICRH System(RF ICRH DAC) to be used for operating of RF Generator in Aditya tokamak. The task of RF ICRH DAC is to control and acquisition of all ICRH system operation with all control loop and acquisition for post analysis of data with java based tool. For pre ionization startup as well as heating experiments using multiple RF Power of different powers and duration. The experiment based upon the idea of using single RF generator to energize antenna inside the tokamak to radiate power twise, out of which first analog pulse will produce pre ionization and second analog pulse will produce heating. The whole system is based on standard client server technology using tcp/ip protocol. DAC Software is based on linux operating system for highly reliable, secure and stable system operation in failsafe manner. Client system is based on tcl/tk like toolkit for user interface with c/c++ like environment which is reliable programming languages widely used on stand alone system operation with server as vxWorks real time operating system like environment. The paper is focused on the Data acquisition and monitoring system software on Aditya RF ICRH System with analog pulses in slave mode with digital pulse in master mode for control acquisition and monitoring and interlocking.

An Implantable Neural Sensing Microsystem with Fiber-Optic Data Transmission and Power Delivery

PubMed Central

Park, Sunmee; Borton, David A.; Kang, Mingyu; Nurmikko, Arto V.; Song, Yoon-Kyu

2013-01-01

We have developed a prototype cortical neural sensing microsystem for brain implantable neuroengineering applications. Its key feature is that both the transmission of broadband, multichannel neural data and power required for the embedded microelectronics are provided by optical fiber access. The fiber-optic system is aimed at enabling neural recording from rodents and primates by converting cortical signals to a digital stream of infrared light pulses. In the full microsystem whose performance is summarized in this paper, an analog-to-digital converter and a low power digital controller IC have been integrated with a low threshold, semiconductor laser to extract the digitized neural signals optically from the implantable unit. The microsystem also acquires electrical power and synchronization clocks via optical fibers from an external laser by using a highly efficient photovoltaic cell on board. The implantable unit employs a flexible polymer substrate to integrate analog and digital microelectronics and on-chip optoelectronic components, while adapting to the anatomical and physiological constraints of the environment. A low power analog CMOS chip, which includes preamplifier and multiplexing circuitry, is directly flip-chip bonded to the microelectrode array to form the cortical neurosensor device. PMID:23666130

Balloon-borne video cassette recorders for digital data storage

NASA Technical Reports Server (NTRS)

Althouse, W. E.; Cook, W. R.

1985-01-01

A high speed, high capacity digital data storage system was developed for a new balloon-borne gamma-ray telescope. The system incorporates economical consumer products: the portable video cassette recorder (VCR) and a relatively newer item - the digital audio processor. The in-flight recording system employs eight VCRs and will provide a continuous data storage rate of 1.4 megabits/sec throughout a 40 hour balloon flight. Data storage capacity is 25 gigabytes and power consumption is only 10 watts.

A look-up-table digital predistortion technique for high-voltage power amplifiers in ultrasonic applications.

PubMed

Gao, Zheng; Gui, Ping

2012-07-01

In this paper, we present a digital predistortion technique to improve the linearity and power efficiency of a high-voltage class-AB power amplifier (PA) for ultrasound transmitters. The system is composed of a digital-to-analog converter (DAC), an analog-to-digital converter (ADC), and a field-programmable gate array (FPGA) in which the digital predistortion (DPD) algorithm is implemented. The DPD algorithm updates the error, which is the difference between the ideal signal and the attenuated distorted output signal, in the look-up table (LUT) memory during each cycle of a sinusoidal signal using the least-mean-square (LMS) algorithm. On the next signal cycle, the error data are used to equalize the signal with negative harmonic components to cancel the amplifier's nonlinear response. The algorithm also includes a linear interpolation method applied to the windowed sinusoidal signals for the B-mode and Doppler modes. The measurement test bench uses an arbitrary function generator as the DAC to generate the input signal, an oscilloscope as the ADC to capture the output waveform, and software to implement the DPD algorithm. The measurement results show that the proposed system is able to reduce the second-order harmonic distortion (HD2) by 20 dB and the third-order harmonic distortion (HD3) by 14.5 dB, while at the same time improving the power efficiency by 18%.

Compact lidar system using laser diode, binary continuous wave power modulation, and an avalanche photodiode-based receiver controlled by a digital signal processor

NASA Astrophysics Data System (ADS)

Ardanuy, Antoni; Comerón, Adolfo

2018-04-01

We analyze the practical limits of a lidar system based on the use of a laser diode, random binary continuous wave power modulation, and an avalanche photodiode (APD)-based photereceiver, combined with the control and computing power of the digital signal processors (DSP) currently available. The target is to design a compact portable lidar system made all in semiconductor technology, with a low-power demand and an easy configuration of the system, allowing change in some of its features through software. Unlike many prior works, we emphasize the use of APDs instead of photomultiplier tubes to detect the return signal and the application of the system to measure not only hard targets, but also medium-range aerosols and clouds. We have developed an experimental prototype to evaluate the behavior of the system under different environmental conditions. Experimental results provided by the prototype are presented and discussed.

76 FR 11680 - Digital Low Power Television, Television Translator, and Television Booster Stations and Digital...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-03

...] Digital Low Power Television, Television Translator, and Television Booster Stations and Digital Class A... Commission's Rules to Establish Rules for Digital Low Power, Television Translator, and Television Booster... Digital Low Power Television Translator, Television Booster Stations, and to Amend Rules for Digital Class...

Wind Energy System Time-domain (WEST) analyzers using hybrid simulation techniques

NASA Technical Reports Server (NTRS)

Hoffman, J. A.

1979-01-01

Two stand-alone analyzers constructed for real time simulation of the complex dynamic characteristics of horizontal-axis wind energy systems are described. Mathematical models for an aeroelastic rotor, including nonlinear aerodynamic and elastic loads, are implemented with high speed digital and analog circuitry. Models for elastic supports, a power train, a control system, and a rotor gimbal system are also included. Limited correlation efforts show good comparisons between results produced by the analyzers and results produced by a large digital simulation. The digital simulation results correlate well with test data.

Electronics for Deep Space Cryogenic Applications

NASA Technical Reports Server (NTRS)

Patterson, R. L.; Hammond, A.; Dickman, J. E.; Gerber, S. S.; Elbuluk, M. E.; Overton, E.

2002-01-01

Deep space probes and planetary exploration missions require electrical power management and control systems that are capable of efficient and reliable operation in very cold temperature environments. Typically, in deep space probes, heating elements are used to keep the spacecraft electronics near room temperature. The utilization of power electronics designed for and operated at low temperature will contribute to increasing efficiency and improving reliability of space power systems. At NASA Glenn Research Center, commercial-off-the-shelf devices as well as developed components are being investigated for potential use at low temperatures. These devices include semiconductor switching devices, magnetics, and capacitors. Integrated circuits such as digital-to-analog and analog-to-digital converters, DC/DC converters, operational amplifiers, and oscillators are also being evaluated. In this paper, results will be presented for selected analog-to-digital converters, oscillators, DC/DC converters, and pulse width modulation (PWM) controllers.

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

Korsah, K.; Ewing, P.D.; Kercel, S.

This paper presents results to date of an NRC-sponsored confirmatory research program initiated at three national laboratories to address environmental compatibility/qualification concerns associated with the use of microprocessor-based safety-related instrumentation and control (I and C) systems in nuclear power plants. The research approach involved evaluating existing military and industrial guidance, identifying the most significant environmental stressors and, for advanced I and C systems in a nuclear power plant, investigating the likely failure modes--both at the integrated circuit and system level--for digital technologies under varying levels of environmental stress (such as smoke exposure and electromagnetic and radio-frequency interference). The insights gainedmore » from these studies are being used to recommend appropriate methods for qualifying safety-related digital equipment in nuclear power plants.« less

Hybrid recursive active filters for duplexing in RF transmitter front-ends

NASA Astrophysics Data System (ADS)

Gottardo, Giuseppe; Donati, Giovanni; Musolff, Christian; Fischer, Georg; Felgentreff, Tilman

2016-08-01

Duplex filters in modern base transceiver stations shape the channel in order to perform common frequency division duplex operations. Usually, they are designed as cavity filters, which are expensive and have large dimensions. Thanks to the emerging digital technology and fast digital converters, it is possible to transfer the efforts of designing analog duplex filters into digital numeric algorithms applied to feedback structures, operating on power. This solution provides the shaping of the signal spectrum directly at the output of the radio frequency (RF) power amplifiers (PAs) relaxing the transmitter design especially in the duplexer and in the antenna sections. The design of a digital baseband feedback applied to the analog power RF amplifiers (hybrid filter) is presented and verified by measurements. A model to describe the hybrid system is investigated, and the relation between phase and resonance peaks of the resulting periodic band-pass transfer function is described. The stability condition of the system is analyzed using Nyquist criterion. A solution involving a number of digital feedback and forward branches is investigated defining the parameters of the recursive structure. This solution allows the closed loop system to show a periodic band pass with up to 500 kHz bandwidth at the output of the RF amplifier. The band-pass magnitude reaches up to 17 dB selectivity. The rejection of the PA noise in the out-of-band frequencies is verified by measurements. The filter is tested with a modulated LTE (Long Term Evolution) signal showing an ACPR (Adjacent Channel Power Ratio) enhancement of 10 dB of the transmitted signal.

Noise power spectra of images from digital mammography detectors.

PubMed

Williams, M B; Mangiafico, P A; Simoni, P U

1999-07-01

Noise characterization through estimation of the noise power spectrum (NPS) is a central component of the evaluation of digital x-ray systems. We begin with a brief review of the fundamentals of NPS theory and measurement, derive explicit expressions for calculation of the one- and two-dimensional (1D and 2D) NPS, and discuss some of the considerations and tradeoffs when these concepts are applied to digital systems. Measurements of the NPS of two detectors for digital mammography are presented to illustrate some of the implications of the choices available. For both systems, two-dimensional noise power spectra obtained over a range of input fluence exhibit pronounced asymmetry between the orthogonal frequency dimensions. The 2D spectra of both systems also demonstrate dominant structures both on and off the primary frequency axes indicative of periodic noise components. Although the two systems share many common noise characteristics, there are significant differences, including markedly different dark-noise magnitudes, differences in NPS shape as a function of both spatial frequency and exposure, and differences in the natures of the residual fixed pattern noise following flat fielding corrections. For low x-ray exposures, quantum noise-limited operation may be possible only at low spatial frequency. Depending on the method of obtaining the 1D NPS (i.e., synthetic slit scanning or slice extraction from the 2D NPS), on-axis periodic structures can be misleadingly smoothed or missed entirely. Our measurements indicate that for these systems, 1D spectra useful for the purpose of detective quantum efficiency calculation may be obtained from thin cuts through the central portion of the calculated 2D NPS. On the other hand, low-frequency spectral values do not converge to an asymptotic value with increasing slit length when 1D spectra are generated using the scanned synthetic slit method. Aliasing can contribute significantly to the digital NPS, especially near the Nyquist frequency. Calculation of the theoretical presampling NPS and explicit inclusion of aliased noise power shows good agreement with measured values.

A Spacecraft Housekeeping System-on-Chip in a Radiation Hardened Structured ASIC

NASA Technical Reports Server (NTRS)

Suarez, George; DuMonthier, Jeffrey J.; Sheikh, Salman S.; Powell, Wesley A.; King, Robyn L.

2012-01-01

Housekeeping systems are essential to health monitoring of spacecraft and instruments. Typically, sensors are distributed across various sub-systems and data is collected using components such as analog-to-digital converters, analog multiplexers and amplifiers. In most cases programmable devices are used to implement the data acquisition control and storage, and the interface to higher level systems. Such discrete implementations require additional size, weight, power and interconnect complexity versus an integrated circuit solution, as well as the qualification of multiple parts. Although commercial devices are readily available, they are not suitable for space applications due the radiation tolerance and qualification requirements. The Housekeeping System-o n-A-Chip (HKSOC) is a low power, radiation hardened integrated solution suitable for spacecraft and instrument control and data collection. A prototype has been designed and includes a wide variety of functions including a 16-channel analog front-end for driving and reading sensors, analog-to-digital and digital-to-analog converters, on-chip temperature sensor, power supply current sense circuits, general purpose comparators and amplifiers, a 32-bit processor, digital I/O, pulse-width modulation (PWM) generators, timers and I2C master and slave serial interfaces. In addition, the device can operate in a bypass mode where the processor is disabled and external logic is used to control the analog and mixed signal functions. The device is suitable for stand-alone or distributed systems where multiple chips can be deployed across different sub-systems as intelligent nodes with computing and processing capabilities.

GaAs VLSI technology and circuit elements for DSP

NASA Astrophysics Data System (ADS)

Mikkelson, James M.

1990-10-01

Recent progress in digital GaAs circuit performance and complexity is presented to demonstrate the current capabilities of GaAs components. High density GaAs process technology and circuit design techniques are described and critical issues for achieving favorable complexity speed power and cost tradeoffs are reviewed. Some DSP building blocks are described to provide examples of what types of DSP systems could be implemented with present GaAs technology. DIGITAL GaAs CIRCUIT CAPABILITIES In the past few years the capabilities of digital GaAs circuits have dramatically increased to the VLSI level. Major gains in circuit complexity and power-delay products have been achieved by the use of silicon-like process technologies and simple circuit topologies. The very high speed and low power consumption of digital GaAs VLSI circuits have made GaAs a desirable alternative to high performance silicon in hardware intensive high speed system applications. An example of the performance and integration complexity available with GaAs VLSI circuits is the 64x64 crosspoint switch shown in figure 1. This switch which is the most complex GaAs circuit currently available is designed on a 30 gate GaAs gate array. It operates at 200 MHz and dissipates only 8 watts of power. The reasons for increasing the level of integration of GaAs circuits are similar to the reasons for the continued increase of silicon circuit complexity. The market factors driving GaAs VLSI are system design methodology system cost power and reliability. System designers are hesitant or unwilling to go backwards to previous design techniques and lower levels of integration. A more highly integrated system in a lower performance technology can often approach the performance of a system in a higher performance technology at a lower level of integration. Higher levels of integration also lower the system component count which reduces the system cost size and power consumption while improving the system reliability. For large gate count circuits the power per gate must be minimized to prevent reliability and cooling problems. The technical factors which favor increasing GaAs circuit complexity are primarily related to reducing the speed and power penalties incurred when crossing chip boundaries. Because the internal GaAs chip logic levels are not compatible with standard silicon I/O levels input receivers and output drivers are needed to convert levels. These I/O circuits add significant delay to logic paths consume large amounts of power and use an appreciable portion of the die area. The effects of these I/O penalties can be reduced by increasing the ratio of core logic to I/O on a chip. DSP operations which have a large number of logic stages between the input and the output are ideal candidates to take advantage of the performance of GaAs digital circuits. Figure 2 is a schematic representation of the I/O penalties encountered when converting from ECL levels to GaAs

Triboelectric Nanogenerator as a Self-Powered Communication Unit for Processing and Transmitting Information.

PubMed

Yu, Aifang; Chen, Xiangyu; Wang, Rui; Liu, Jingyu; Luo, Jianjun; Chen, Libo; Zhang, Yang; Wu, Wei; Liu, Caihong; Yuan, Hongtao; Peng, Mingzeng; Hu, Weiguo; Zhai, Junyi; Wang, Zhong Lin

2016-04-26

In this paper, we demonstrate an application of a triboelectric nanogenerator (TENG) as a self-powered communication unit. An elaborately designed TENG is used to translate a series of environmental triggering signals into binary digital signals and drives an electronic-optical device to transmit binary digital data in real-time without an external power supply. The elaborately designed TENG is built in a membrane structure that can effectively drive the electronic-optical device in a bandwidth from 1.30 to 1.65 kHz. Two typical communication modes (amplitude-shift keying and frequency-shift keying) are realized through the resonant response of TENG to different frequencies, and two digital signals, i.e., "1001" and "0110", are successfully transmitted and received through this system, respectively. Hence, in this study, a simple but efficient method for directly transmitting ambient vibration to the receiver as a digital signal is established using an elaborately designed TENG and an optical communication technique. This type of the communication system, as well as the implementation method presented, exhibits great potential for applications in the smart city, smart home, password authentication, and so on.

Digital Signal Processing and Control for the Study of Gene Networks

NASA Astrophysics Data System (ADS)

Shin, Yong-Jun

2016-04-01

Thanks to the digital revolution, digital signal processing and control has been widely used in many areas of science and engineering today. It provides practical and powerful tools to model, simulate, analyze, design, measure, and control complex and dynamic systems such as robots and aircrafts. Gene networks are also complex dynamic systems which can be studied via digital signal processing and control. Unlike conventional computational methods, this approach is capable of not only modeling but also controlling gene networks since the experimental environment is mostly digital today. The overall aim of this article is to introduce digital signal processing and control as a useful tool for the study of gene networks.

Digital Signal Processing and Control for the Study of Gene Networks.

PubMed

Shin, Yong-Jun

2016-04-22

Thanks to the digital revolution, digital signal processing and control has been widely used in many areas of science and engineering today. It provides practical and powerful tools to model, simulate, analyze, design, measure, and control complex and dynamic systems such as robots and aircrafts. Gene networks are also complex dynamic systems which can be studied via digital signal processing and control. Unlike conventional computational methods, this approach is capable of not only modeling but also controlling gene networks since the experimental environment is mostly digital today. The overall aim of this article is to introduce digital signal processing and control as a useful tool for the study of gene networks.

Digital Signal Processing and Control for the Study of Gene Networks

PubMed Central

Shin, Yong-Jun

2016-01-01

Thanks to the digital revolution, digital signal processing and control has been widely used in many areas of science and engineering today. It provides practical and powerful tools to model, simulate, analyze, design, measure, and control complex and dynamic systems such as robots and aircrafts. Gene networks are also complex dynamic systems which can be studied via digital signal processing and control. Unlike conventional computational methods, this approach is capable of not only modeling but also controlling gene networks since the experimental environment is mostly digital today. The overall aim of this article is to introduce digital signal processing and control as a useful tool for the study of gene networks. PMID:27102828

Power in the loop real time simulation platform for renewable energy generation

NASA Astrophysics Data System (ADS)

Li, Yang; Shi, Wenhui; Zhang, Xing; He, Guoqing

2018-02-01

Nowadays, a large scale of renewable energy sources has been connecting to power system and the real time simulation platform is widely used to carry out research on integration control algorithm, power system stability etc. Compared to traditional pure digital simulation and hardware in the loop simulation, power in the loop simulation has higher accuracy and degree of reliability. In this paper, a power in the loop analog digital hybrid simulation platform has been built and it can be used not only for the single generation unit connecting to grid, but also for multiple new energy generation units connecting to grid. A wind generator inertia control experiment was carried out on the platform. The structure of the inertia control platform was researched and the results verify that the platform is up to need for renewable power in the loop real time simulation.

A Low-Power All-Digital on-Chip CMOS Oscillator for a Wireless Sensor Node

PubMed Central

Sheng, Duo; Hong, Min-Rong

2016-01-01

This paper presents an all-digital low-power oscillator for reference clocks in wireless body area network (WBAN) applications. The proposed on-chip complementary metal-oxide-semiconductor (CMOS) oscillator provides low-frequency clock signals with low power consumption, high delay resolution, and low circuit complexity. The cascade-stage structure of the proposed design simultaneously achieves high resolution and a wide frequency range. The proposed hysteresis delay cell further reduces the power consumption and hardware costs by 92.4% and 70.4%, respectively, relative to conventional designs. The proposed design is implemented in a standard performance 0.18 μm CMOS process. The measured operational frequency ranged from 7 to 155 MHz, and the power consumption was improved to 79.6 μW (@7 MHz) with a 4.6 ps resolution. The proposed design can be implemented in an all-digital manner, which is highly desirable for system-level integration. PMID:27754439

A Low-Power All-Digital on-Chip CMOS Oscillator for a Wireless Sensor Node.

PubMed

Sheng, Duo; Hong, Min-Rong

2016-10-14

This paper presents an all-digital low-power oscillator for reference clocks in wireless body area network (WBAN) applications. The proposed on-chip complementary metal-oxide-semiconductor (CMOS) oscillator provides low-frequency clock signals with low power consumption, high delay resolution, and low circuit complexity. The cascade-stage structure of the proposed design simultaneously achieves high resolution and a wide frequency range. The proposed hysteresis delay cell further reduces the power consumption and hardware costs by 92.4% and 70.4%, respectively, relative to conventional designs. The proposed design is implemented in a standard performance 0.18 μm CMOS process. The measured operational frequency ranged from 7 to 155 MHz, and the power consumption was improved to 79.6 μW (@7 MHz) with a 4.6 ps resolution. The proposed design can be implemented in an all-digital manner, which is highly desirable for system-level integration.

Short circuit protection for a power distribution system

NASA Technical Reports Server (NTRS)

Owen, J. R., III

1969-01-01

Sensing circuit detects when the output from a matrix is present and when it should be present. The circuit provides short circuit protection for a power distribution system where the selection of the driven load is accomplished by digital logic.

Proceedings of the Fourth Annual Workshop on the Use of Digital Computers in Process Control.

ERIC Educational Resources Information Center

Smith, Cecil L., Ed.

Contents: Computer hardware testing (results of vendor-user interaction); CODIL (a new language for process control programing); the design and implementation of control systems utilizing CRT display consoles; the systems contractor - valuable professional or unnecessary middle man; power station digital computer applications; from inspiration to…

On-chip temperature-based digital signal processing for customized wireless microcontroller

NASA Astrophysics Data System (ADS)

Farhah Razanah Faezal, Siti; Isa, Mohd Nazrin Md; Harun, Azizi; Nizam Mohyar, Shaiful; Bahari Jambek, Asral

2017-11-01

Increases in die size and power density inside system-on-chip (SoC) design have brought thermal issue inside the system. Uneven heat-up and increasing in temperature offset on-chip has become a major factor that can limits the system performance. This paper presents the design and simulation of a temperature-based digital signal processing for modern system-on-chip design using the Verilog HDL. This design yields continuous monitoring of temperature and reacts to specified conditions. The simulation of the system has been done on Altera Quartus Software v. 14. With system above, microcontroller can achieve nominal power dissipation and operation is within the temperature range due to the incorporate of an interrupt-based system.

Development of ATC for High Speed and High Density Commuter Line

NASA Astrophysics Data System (ADS)

Okutani, Tamio; Nakamura, Nobuyuki; Araki, Hisato; Irie, Shouji; Osa, Hiroki; Sano, Minoru; Ikeda, Keigo; Ozawa, Hiroyuki

A new ATC (Automatic Train Control) system has been developed with solutions to realize short train headway by assured braking utilizing digital data transmission via rails; the digital data for the ATP (Automatic Train Protection) function; and to achieve EMC features for both AC and DC sections. The DC section is of the unprecedented DC traction power supply system utilizing IGBT PWM converter at all DC substations. Within the AC section, train traction force is controlled by PWM converter/inverters. The carrier frequencies of the digital data signals and chopping frequency of PWM traction power converters on-board are decided via spectral analysis of noise up to degraded mode cases of equipment. Developed system was equipped to the Tukuba Express Line, new commuter line of Tokyo metropolitan area, and opened since Aug. 2005.

Investigation of the impact of main control room digitalization on operators cognitive reliability in nuclear power plants.

PubMed

Zhou, Yong; Mu, Haiying; Jiang, Jianjun; Zhang, Li

2012-01-01

Currently, there is a trend in nuclear power plants (NPPs) toward introducing digital and computer technologies into main control rooms (MCRs). Safe generation of electric power in NPPs requires reliable performance of cognitive tasks such as fault detection, diagnosis, and response planning. The digitalization of MCRs has dramatically changed the whole operating environment, and the ways operators interact with the plant systems. If the design and implementation of the digital technology is incompatible with operators' cognitive characteristics, it may have negative effects on operators' cognitive reliability. Firstly, on the basis of three essential prerequisites for successful cognitive tasks, a causal model is constructed to reveal the typical human performance issues arising from digitalization. The cognitive mechanisms which they impact cognitive reliability are analyzed in detail. Then, Bayesian inference is used to quantify and prioritize the influences of these factors. It suggests that interface management and unbalanced workload distribution have more significant impacts on operators' cognitive reliability.

Design of a hybrid battery charger system fed by a wind-turbine and photovoltaic power generators.

PubMed

Chang Chien, Jia-Ren; Tseng, Kuo-Ching; Yan, Bo-Yi

2011-03-01

This paper is aimed to develop a digital signal processor (DSP) for controlling a solar cell and wind-turbine hybrid charging system. The DSP consists of solar cells, a wind turbine, a lead acid battery, and a buck-boost converter. The solar cells and wind turbine serve as the system's main power sources and the battery as an energy storage element. The output powers of solar cells and wind turbine have large fluctuations with the weather and climate conditions. These unstable powers can be adjusted by a buck-boost converter and thus the most suitable output powers can be obtained. This study designs a booster by using a dsPIC30F4011 digital signal controller as a core processor. The DSP is controlled by the perturbation and observation methods to obtain an effective energy circuit with a full 100 W charging system. Also, this DSP can, day and night, be easily controlled and charged by a simple program, which can change the state of the system to reach a flexible application based on the reading weather conditions.

78 FR 47014 - Configuration Management Plans for Digital Computer Software Used in Safety Systems of Nuclear...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-02

... Software Used in Safety Systems of Nuclear Power Plants AGENCY: Nuclear Regulatory Commission. ACTION... Computer Software Used in Safety Systems of Nuclear Power Plants.'' This RG endorses, with clarifications... Electrical and Electronic Engineers (IEEE) Standard 828-2005, ``IEEE Standard for Software Configuration...

Investigation of design considerations for a complex demodulation filter

NASA Technical Reports Server (NTRS)

Stoughton, J. W.

1984-01-01

The digital design of an adaptive digital filter to be employed in the processing of microwave remote sensor data was developed. In particular, a complex demodulation approach was developed to provide narrow band power estimation for a proposed Doppler scatterometer system. This scatterometer was considered for application in the proposed National Oceanographic survey satellite, on an improvement of SEASAT features. A generalized analysis of complex diagrams for the digital architecture component of the proposed system.

Low power sensor network for wireless condition monitoring

NASA Astrophysics Data System (ADS)

Richter, Ch.; Frankenstein, B.; Schubert, L.; Weihnacht, B.; Friedmann, H.; Ebert, C.

2009-03-01

For comprehensive fatigue tests and surveillance of large scale structures, a vibration monitoring system working in the Hz and sub Hz frequency range was realized and tested. The system is based on a wireless sensor network and focuses especially on the realization of a low power measurement, signal processing and communication. Regarding the development, we met the challenge of synchronizing the wireless connected sensor nodes with sufficient accuracy. The sensor nodes ware realized by compact, sensor near signal processing structures containing components for analog preprocessing of acoustic signals, their digitization, algorithms for data reduction and network communication. The core component is a digital micro controller which performs the basic algorithms necessary for the data acquisition synchronization and the filtering. As a first application, the system was installed in a rotor blade of a wind power turbine in order to monitor the Eigen modes over a longer period of time. Currently the sensor nodes are battery powered.

Analysis and simulation tools for solar array power systems

NASA Astrophysics Data System (ADS)

Pongratananukul, Nattorn

This dissertation presents simulation tools developed specifically for the design of solar array power systems. Contributions are made in several aspects of the system design phases, including solar source modeling, system simulation, and controller verification. A tool to automate the study of solar array configurations using general purpose circuit simulators has been developed based on the modeling of individual solar cells. Hierarchical structure of solar cell elements, including semiconductor properties, allows simulation of electrical properties as well as the evaluation of the impact of environmental conditions. A second developed tool provides a co-simulation platform with the capability to verify the performance of an actual digital controller implemented in programmable hardware such as a DSP processor, while the entire solar array including the DC-DC power converter is modeled in software algorithms running on a computer. This "virtual plant" allows developing and debugging code for the digital controller, and also to improve the control algorithm. One important task in solar arrays is to track the maximum power point on the array in order to maximize the power that can be delivered. Digital controllers implemented with programmable processors are particularly attractive for this task because sophisticated tracking algorithms can be implemented and revised when needed to optimize their performance. The proposed co-simulation tools are thus very valuable in developing and optimizing the control algorithm, before the system is built. Examples that demonstrate the effectiveness of the proposed methodologies are presented. The proposed simulation tools are also valuable in the design of multi-channel arrays. In the specific system that we have designed and tested, the control algorithm is implemented on a single digital signal processor. In each of the channels the maximum power point is tracked individually. In the prototype we built, off-the-shelf commercial DC-DC converters were utilized. At the end, the overall performance of the entire system was evaluated using solar array simulators capable of simulating various I-V characteristics, and also by using an electronic load. Experimental results are presented.

Performance of the Fully Digital FPGA-Based Front-End Electronics for the GALILEO Array

NASA Astrophysics Data System (ADS)

Barrientos, D.; Bellato, M.; Bazzacco, D.; Bortolato, D.; Cocconi, P.; Gadea, A.; González, V.; Gulmini, M.; Isocrate, R.; Mengoni, D.; Pullia, A.; Recchia, F.; Rosso, D.; Sanchis, E.; Toniolo, N.; Ur, C. A.; Valiente-Dobón, J. J.

2015-12-01

In this work we present the architecture and results of a fully digital Front End Electronics (FEE) read out system developed for the GALILEO array. The FEE system, developed in collaboration with the Advanced Gamma Tracking Array (AGATA) collaboration, is composed of three main blocks: preamplifiers, digitizers and preprocessing electronics. The slow control system contains a custom Linux driver, a dynamic library and a server implementing network services. This work presents the first results of the digital FEE system coupled with a GALILEO germanium detector, which has demonstrated the capability to achieve an energy resolution of 1.530/00 at an energy of 1.33 MeV, similar to the one obtained with a conventional analog system. While keeping a good performance in terms of energy resolution, digital electronics will allow to instrument the full GALILEO array with a versatile system with high integration and low power consumption and costs.

A microcomputer-based data acquisition system for ECG, body and ambient temperatures measurement during bathing.

PubMed

Uokawa, Y; Yonezawa, Y; Caldwell, W M; Hahn, A W

2000-01-01

A data acquisition system employing a low power 8 bit microcomputer has been developed for heart rate variability monitoring before, during and after bathing. The system consists of three integral chest electrodes, two temperature sensors, an instrumentation amplifier, a low power 8-bit single chip microcomputer (SMC) and a 4 MB compact flash memory (CFM). The ECG from the electrodes is converted to an 8-bit digital format at a 1 ms rate by an A/D converter in the SMC. Both signals from the body and ambient temperature sensors are converted to an 8-bit digital format every 1 second. These data are stored by the CFM. The system is powered by a rechargeable 3.6 V lithium battery. The 4 x 11 x 1 cm system is encapsulated in epoxy and silicone, yielding a total volume of 44 cc. The weight is 100 g.

Balloon-borne video cassette recorders for digital data storage

NASA Technical Reports Server (NTRS)

Althouse, W. E.; Cook, W. R.

1985-01-01

A high-speed, high-capacity digital data storage system has been developed for a new balloon-borne gamma-ray telescope. The system incorporates sophisticated, yet easy to use and economical consumer products: the portable video cassette recorder (VCR) and a relatively newer item - the digital audio processor. The in-flight recording system employs eight VCRs and will provide a continuous data storage rate of 1.4 megabits/sec throughout a 40 hour balloon flight. Data storage capacity is 25 gigabytes and power consumption is only 10 watts.

A battery-free multichannel digital neural/EMG telemetry system for flying insects.

PubMed

Thomas, Stewart J; Harrison, Reid R; Leonardo, Anthony; Reynolds, Matthew S

2012-10-01

This paper presents a digital neural/EMG telemetry system small enough and lightweight enough to permit recording from insects in flight. It has a measured flight package mass of only 38 mg. This system includes a single-chip telemetry integrated circuit (IC) employing RF power harvesting for battery-free operation, with communication via modulated backscatter in the UHF (902-928 MHz) band. An on-chip 11-bit ADC digitizes 10 neural channels with a sampling rate of 26.1 kSps and 4 EMG channels at 1.63 kSps, and telemeters this data wirelessly to a base station. The companion base station transceiver includes an RF transmitter of +36 dBm (4 W) output power to wirelessly power the telemetry IC, and a digital receiver with a sensitivity of -70 dBm for 10⁻⁵ BER at 5.0 Mbps to receive the data stream from the telemetry IC. The telemetry chip was fabricated in a commercial 0.35 μ m 4M1P (4 metal, 1 poly) CMOS process. The die measures 2.36 × 1.88 mm, is 250 μm thick, and is wire bonded into a flex circuit assembly measuring 4.6 × 6.8 mm.

An implementation of a reference symbol approach to generic modulation in fading channels

NASA Technical Reports Server (NTRS)

Young, R. J.; Lodge, J. H.; Pacola, L. C.

1990-01-01

As mobile satellite communications systems evolve over the next decade, they will have to adapt to a changing tradeoff between bandwidth and power. This paper presents a flexible approach to digital modulation and coding that will accommodate both wideband and narrowband schemes. This architecture could be the basis for a family of modems, each satisfying a specific power and bandwidth constraint, yet all having a large number of common signal processing blocks. The implementation of this generic approach, with general purpose digital processors for transmission of 4.8 kilobits per sec. digitally encoded speech, is described.

A REVIEW OF HUMAN-SYSTEM INTERFACE DESIGN ISSUES OBSERVED DURING ANALOG-TO-DIGITAL AND DIGITAL-TO-DIGITAL MIGRATIONS IN U.S. NUCLEAR POWER PLANTS

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

Kovesdi, C.; Joe, J.

The United States (U.S.) Department of Energy (DOE) Light Water Reactor Sustainability (LWRS) program is developing a scientific basis through targeted research and development (R&D) to support the U.S. nuclear power plant (NPP) fleet in extending their existing licensing period and ensuring their long-term reliability, productivity, safety, and security. Over the last several years, human factors engineering (HFE) professionals at the Idaho National Laboratory (INL) have supported the LWRS Advanced Instrumentation, Information, and Control (II&C) System Technologies pathway across several U.S. commercial NPPs in analog-to-digital migrations (i.e., turbine control systems) and digital-to-digital migrations (i.e., Safety Parameter Display System). These effortsmore » have included in-depth human factors evaluation of proposed human-system interface (HSI) design concepts against established U.S. Nuclear Regulatory Commission (NRC) design guidelines from NUREG-0700, Rev 2 to inform subsequent HSI design prior to transitioning into Verification and Validation. This paper discusses some of the overarching design issues observed from these past HFE evaluations. In addition, this work presents some observed challenges such as common tradeoffs utilities are likely to face when introducing new HSI technologies into NPP hybrid control rooms. The primary purpose of this work is to distill these observed design issues into general HSI design guidance that industry can use in early stages of HSI design.« less

Nuclear Science Symposium, 25th, and Symposium on Nuclear Power Systems, 10th, Washington, D.C., October 18-20, 1978, Proceedings

NASA Technical Reports Server (NTRS)

1979-01-01

Detectors of various types are discussed, taking into account drift chambers, calorimetry, multiwire proportional chambers, signal processing, the use of semiconductors, and photo/optical applications. Circuits are considered along with instrumentation for space, nuclear medicine instrumentation, data acquisition and systems, environmental instrumentation, reactor instrumentation, and nuclear power systems. Attention is given to a new approach to high accuracy gaseous detectors, the current status of electron mobility and free-ion yield in high mobility liquids, a digital drift chamber digitizer system, the stability of oxides in high purity germanium, the quadrant photomultiplier, and the theory of imaging with a very limited number of projections.

Toward a digital camera to rival the human eye

NASA Astrophysics Data System (ADS)

Skorka, Orit; Joseph, Dileepan

2011-07-01

All things considered, electronic imaging systems do not rival the human visual system despite notable progress over 40 years since the invention of the CCD. This work presents a method that allows design engineers to evaluate the performance gap between a digital camera and the human eye. The method identifies limiting factors of the electronic systems by benchmarking against the human system. It considers power consumption, visual field, spatial resolution, temporal resolution, and properties related to signal and noise power. A figure of merit is defined as the performance gap of the weakest parameter. Experimental work done with observers and cadavers is reviewed to assess the parameters of the human eye, and assessment techniques are also covered for digital cameras. The method is applied to 24 modern image sensors of various types, where an ideal lens is assumed to complete a digital camera. Results indicate that dynamic range and dark limit are the most limiting factors. The substantial functional gap, from 1.6 to 4.5 orders of magnitude, between the human eye and digital cameras may arise from architectural differences between the human retina, arranged in a multiple-layer structure, and image sensors, mostly fabricated in planar technologies. Functionality of image sensors may be significantly improved by exploiting technologies that allow vertical stacking of active tiers.

78 FR 27443 - Advisory Committee on Reactor Safeguards (ACRS); Meeting of the ACRS Subcommittee on Digital I&C...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-10

...-1207), ``Test Documentation for Digital Computer Software Used in Safety Systems of Nuclear Power... would result in a major inconvenience. If attending this meeting, please enter through the One White...

Integrated unaligned resonant modulator tuning

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

Zortman, William A.; Lentine, Anthony L.

Methods and systems for tuning a resonant modulator are disclosed. One method includes receiving a carrier signal modulated by the resonant modulator with a stream of data having an approximately equal number of high and low bits, determining an average power of the modulated carrier signal, comparing the average power to a predetermined threshold, and operating a tuning device coupled to the resonant modulator based on the comparison of the average power and the predetermined threshold. One system includes an input structure, a plurality of processing elements, and a digital control element. The input structure is configured to receive, frommore » the resonant modulator, a modulated carrier signal. The plurality of processing elements are configured to determine an average power of the modulated carrier signal. The digital control element is configured to operate a tuning device coupled to the resonant modulator based on the average power of the modulated carrier signal.« less

Systems study for an Integrated Digital-Electric Aircraft (IDEA)

NASA Technical Reports Server (NTRS)

Tagge, G. E.; Irish, L. A.; Bailey, A. R.

1985-01-01

The results of the Integrated Digital/Electric Aircraft (IDEA) Study are presented. Airplanes with advanced systems were, defined and evaluated, as a means of identifying potential high payoff research tasks. A baseline airplane was defined for comparison, typical of a 1990's airplane with advanced active controls, propulsion, aerodynamics, and structures technology. Trade studies led to definition of an IDEA airplane, with extensive digital systems and electric secondary power distribution. This airplane showed an improvement of 3% in fuel use and 1.8% in DOC relative to the baseline configuration. An alternate configuration, an advanced technology turboprop, was also evaluated, with greater improvement supported by digital electric systems. Recommended research programs were defined for high risk, high payoff areas appropriate for implementation under NASA leadership.

Micro-electro-mechanical systems (MEMS) and agile lensing-based modules for communications, sensing and signal processing

NASA Astrophysics Data System (ADS)

Reza, Syed Azer

This dissertation proposes the use of the emerging Micro-Electro-Mechanical Systems (MEMS) and agile lensing optical device technologies to design novel and powerful signal conditioning and sensing modules for advanced applications in optical communications, physical parameter sensing and RF/optical signal processing. For example, these new module designs have experimentally demonstrated exceptional features such as stable loss broadband operations and high > 60 dB optical dynamic range signal filtering capabilities. The first part of the dissertation describes the design and demonstration of digital MEMS-based signal processing modules for communication systems and sensor networks using the TI DLP (Digital Light Processing) technology. Examples of such modules include optical power splitters, narrowband and broadband variable fiber optical attenuators, spectral shapers and filters. Compared to prior works, these all-digital designs have advantages of repeatability, accuracy, and reliability that are essential for advanced communications and sensor applications. The next part of the dissertation proposes, analyzes and demonstrates the use of analog opto-fluidic agile lensing technology for sensor networks and test and measurement systems. Novel optical module designs for distance sensing, liquid level sensing, three-dimensional object shape sensing and variable photonic delay lines are presented and experimentally demonstrated. Compared to prior art module designs, the proposed analog-mode modules have exceptional performances, particularly for extreme environments (e.g., caustic liquids) where the free-space agile beam-based sensor provide remote non-contact access for physical sensing operations. The dissertation also presents novel modules involving hybrid analog-digital photonic designs that make use of the different optical device technologies to deliver the best features of both analog and digital optical device operations and controls. Digital controls are achieved through the use of the digital MEMS technology and analog controls are realized by employing opto-fluidic agile lensing technology and acousto-optic technology. For example, variable fiber-optic attenuators and spectral filters are proposed using the hybrid design. Compared to prior art module designs, these hybrid designs provide a higher module dynamic range and increased resolution that are critical in various advanced system applications. In summary, the dissertation shows the added power of hybrid optical designs using both the digital and analog photonic signal processing versus just all-digital or all-analog module designs.

KM3NeT Digital Optical Module electronics

NASA Astrophysics Data System (ADS)

Real, Diego

2016-04-01

The KM3NeT collaboration is currently building of a neutrino telescope with a volume of several cubic kilometres at the bottom of the Mediterranean Sea. The telescope consists of a matrix of Digital Optical Modules that will detect the Cherenkov light originated by the interaction of the neutrinos in the proximity of the detector. This contribution describes the main components of the read-out electronics of the Digital Optical Module: the Power Board, which delivers all the power supply required by the Digital Optical Molule electronics; the Central Logic Board, the main core of the read-out system, hosting 31 Time to Digital Converters with 1 ns resolution and the White Rabbit protocol embedded in the Central Logic Board Field Programmable Gate Array; the Octopus boards, that transfer the Low Voltage Digital Signals from the PMT bases to the Central Logic Board and finally the PMT bases, in charge of converting the analogue signal produced in the 31 3" PMTs into a Low Voltage Digital Signal.

Degradations to microprocessor-based systems due to environmental stressors

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

Messman, P. A.; Peilai, Z.; Goodenow, D. A.

Recent studies indicate that EMI/RFI is the most significant environmental Stressor with potential for leading to digital systems degradation and failure. With digital I and C and wireless technology becoming standard in many industrial environments, nuclear power plant operators of current and future plants will or already have implemented these technologies seeking to leverage the economic benefits of such technology. With digital I and C systems' higher susceptibility to EMI/RFI and the increased environmental noise introduced by wireless-based systems, this produces a dangerous combination that could lead to logic errors, equipment damage, and faults in digital I and C. Failuresmore » to these systems, especially to safety-critical systems, could lead to loss of system, which would pose a safety risk and decrease in operational efficiency. In order to better understand system degradations by these means and aid in regulation and guidance, we propose to experimentally study the susceptibility of digital I and C to wireless technology. (authors)« less

Holostrain system: a powerful tool for experimental mechanics

NASA Astrophysics Data System (ADS)

Sciammarella, Cesar A.; Bhat, Gopalakrishna K.

1992-09-01

A portable holographic interferometer that can be used to measure displacements and strains in all kinds of mechanical components and structures is described. The holostrain system captures images on a TV camera that detects interference patterns produced by laser illumination. The video signals are digitized. The digitized interferograms are processed by a fast processing system. The output of the system are the strains or the stresses of the observed mechanical component or structure.

CMOS based capacitance to digital converter circuit for MEMS sensor

NASA Astrophysics Data System (ADS)

Rotake, D. R.; Darji, A. D.

2018-02-01

Most of the MEMS cantilever based system required costly instruments for characterization, processing and also has large experimental setups which led to non-portable device. So there is a need of low cost, highly sensitive, high speed and portable digital system. The proposed Capacitance to Digital Converter (CDC) interfacing circuit converts capacitance to digital domain which can be easily processed. Recent demand microcantilever deflection is part per trillion ranges which change the capacitance in 1-10 femto farad (fF) range. The entire CDC circuit is designed using CMOS 250nm technology. Design of CDC circuit consists of a D-latch and two oscillators, namely Sensor controlled oscillator (SCO) and digitally controlled oscillator (DCO). The D-latch is designed using transmission gate based MUX for power optimization. A CDC design of 7-stage, 9-stage and 11-stage tested for 1-18 fF and simulated using mentor graphics Eldo tool with parasitic. Since the proposed design does not use resistance component, the total power dissipation is reduced to 2.3621 mW for CDC designed using 9-stage SCO and DCO.

12-bit 32 channel 500 MS/s low-latency ADC for particle accelerators real-time control

NASA Astrophysics Data System (ADS)

Karnitski, Anton; Baranauskas, Dalius; Zelenin, Denis; Baranauskas, Gytis; Zhankevich, Alexander; Gill, Chris

2017-09-01

Particle beam control systems require real-time low latency digital feedback with high linearity and dynamic range. Densely packed electronic systems employ high performance multichannel digitizers causing excessive heat dissipation. Therefore, low power dissipation is another critical requirement for these digitizers. A described 12-bit 500 MS/s ADC employs a sub-ranging architecture based on a merged sample & hold circuit, a residue C-DAC and a shared 6-bit flash core ADC. The core ADC provides a sequential coarse and fine digitization featuring a latency of two clock cycles. The ADC is implemented in a 28 nm CMOS process and consumes 4 mW of power per channel from a 0.9 V supply (interfacing and peripheral circuits are excluded). Reduced power consumption and small on-chip area permits the implementation of 32 ADC channels on a 10.7 mm2 chip. The ADC includes a JESD204B standard compliant output data interface operated at the 7.5 Gbps/ch rate. To minimize the data interface related time latency, a special feature permitting to bypass the JESD204B interface is built in. DoE Phase I Award Number: DE-SC0017213.

47 CFR 73.6019 - Digital Class A TV station protection of low power TV, TV translator, digital low power TV and...

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 4 2011-10-01 2011-10-01 false Digital Class A TV station protection of low power TV, TV translator, digital low power TV and digital TV translator stations. 73.6019 Section 73... BROADCAST SERVICES Class A Television Broadcast Stations § 73.6019 Digital Class A TV station protection of...

Design of 90×8 ROIC with pixel level digital TDI implementation for scanning type LWIR FPAs

NASA Astrophysics Data System (ADS)

Ceylan, Omer; Kayahan, Huseyin; Yazici, Melik; Gurbuz, Yasar

2013-06-01

Design of a 90×8 CMOS readout integrated circuit (ROIC) based on pixel level digital time delay integration (TDI) for scanning type LWIR focal plane arrays (FPAs) is presented. TDI is implemented on 8 pixels which improves the SNR of the system with a factor of √8. Oversampling rate of 3 improves the spatial resolution of the system. TDI operation is realized with a novel under-pixel analog-to-digital converter, which improves the noise performance of ROIC with a lower quantization noise. Since analog signal is converted to digital domain in-pixel, non-uniformities and inaccuracies due to analog signal routing over large chip area is eliminated. Contributions of each pixel for proper TDI operation are added in summation counters, no op-amps are used for summation, hence power consumption of ROIC is lower than its analog counterparts. Due to lack of multiple capacitors or summation amplifiers, ROIC occupies smaller chip area compared to its analog counterparts. ROIC is also superior to its digital counterparts due to novel digital TDI implementation in terms of power consumption, noise and chip area. ROIC supports bi-directional scan, multiple gain settings, bypass operation, automatic gain adjustment, pixel select/deselect, and is programmable through serial or parallel interface. Input referred noise of ROIC is less than 750 rms electrons, while power consumption is less than 20mW. ROIC is designed to perform both in room and cryogenic temperatures.

A new digital land mobile satellite system

NASA Astrophysics Data System (ADS)

Schneider, Philip

A description is given of the different digital services planned to be carried over existing and planned mobile satellite systems. These systems are then compared with analog services in terms of bandwidth and power efficiency. This comparison provides the rationale for the establishment of a digital land mobile satellite service (DLMSS) to use frequencies that are currently available but not yet assigned to a domestic mobile satellite system in the United States. The focus here is on the expected advantages of digital transmission techniques in accommodating additional mobile satellite systems in this portion of the spectrum, and how such techniques can fully satisfy voice, data and facsimile mobile communications requirements in a cost effective manner. A description is given of the system architecture of the DMLSS service proposed by the Geostar Messaging Corporation (GMC) and the market potential of DLMSS.

A new digital land mobile satellite system

NASA Technical Reports Server (NTRS)

Schneider, Philip

1990-01-01

A description is given of the different digital services planned to be carried over existing and planned mobile satellite systems. These systems are then compared with analog services in terms of bandwidth and power efficiency. This comparison provides the rationale for the establishment of a digital land mobile satellite service (DLMSS) to use frequencies that are currently available but not yet assigned to a domestic mobile satellite system in the United States. The focus here is on the expected advantages of digital transmission techniques in accommodating additional mobile satellite systems in this portion of the spectrum, and how such techniques can fully satisfy voice, data and facsimile mobile communications requirements in a cost effective manner. A description is given of the system architecture of the DMLSS service proposed by the Geostar Messaging Corporation (GMC) and the market potential of DLMSS.

Digital Electronic Engine Control (DEEC) Flight Evaluation in an F-15 Airplane

NASA Technical Reports Server (NTRS)

1984-01-01

Flight evaluation in an F-15 aircraft by digital electronic engine control (DEEC) was investigated. Topics discussed include: system description, F100 engine tests, effects of inlet distortion on static pressure probe, flight tests, digital electronic engine control fault detection and accommodation flight evaluation, flight evaluation of a hydromechanical backup control, augmentor transient capability of an F100 engine, investigation of nozzle instability, real time in flight thrust calculation, and control technology for future aircraft propulsion systems. It is shown that the DEEC system is a powerful and flexible controller for the F100 engine.

Evaluation of a closed loop inductive power transmission system on an awake behaving animal subject.

PubMed

Kiani, Mehdi; Kwon, Ki Yong; Zhang, Fei; Oweiss, Karim; Ghovanloo, Maysam

2011-01-01

This paper presents in vivo experimental results for a closed loop wireless power transmission system to implantable devices on an awake behaving animal subject. In this system, wireless power transmission takes place across an inductive link, controlled by a commercial off-the-shelf (COTS) radio frequency identification (RFID) transceiver (TRF7960) operating at 13.56 MHz. Induced voltage on the implantable secondary coil is rectified, digitized by a 10-bit analog to digital converter, and transmitted back to the primary via back telemetry. Transmitter (Tx) and receiver (Rx) circuitry were mounted on the back of an adult rat with a nominal distance of ~7 mm between their coils. Our experiments showed that the closed loop system was able to maintain the Rx supply voltage at the designated 3.8 V despite changes in the coils' relative distance and alignment due to animal movements. The Tx power consumption changed between 410 ~ 560 mW in order to deliver 27 mW to the receiver. The open loop system, on the other hand, showed undesired changes in the Rx supply voltage while the Tx power consumption was constant at 660 mW.

Energy-efficient hierarchical processing in the network of wireless intelligent sensors (WISE)

NASA Astrophysics Data System (ADS)

Raskovic, Dejan

Sensor network nodes have benefited from technological advances in the field of wireless communication, processing, and power sources. However, the processing power of microcontrollers is often not sufficient to perform sophisticated processing, while the power requirements of digital signal processing boards or handheld computers are usually too demanding for prolonged system use. We are matching the intrinsic hierarchical nature of many digital signal-processing applications with the natural hierarchy in distributed wireless networks, and building the hierarchical system of wireless intelligent sensors. Our goal is to build a system that will exploit the hierarchical organization to optimize the power consumption and extend battery life for the given time and memory constraints, while providing real-time processing of sensor signals. In addition, we are designing our system to be able to adapt to the current state of the environment, by dynamically changing the algorithm through procedure replacement. This dissertation presents the analysis of hierarchical environment and methods for energy profiling used to evaluate different system design strategies, and to optimize time-effective and energy-efficient processing.

The trend of digital control system design for nuclear power plants in Korea

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

Park, S. H.; Jung, H. Y.; Yang, C. Y.

2006-07-01

Currently there are 20 nuclear power plants (NPPs) in operation, and 6 more units are under construction in Korea. The control systems of those NPPs have also been developed together with the technology advancement. Control systems started with On-Off control using the relay logic, had been evolved into Solid-State logic using TTL ICs, and applied with the micro-processors since the Yonggwang NPP Units 3 and 4 which started its construction in 1989. Multiplexers are also installed at the local plant areas to collect field input and to send output signals while communicating with the controllers located in the system cabinetsmore » near the main control room in order to reduce the field wiring cables. The design of the digital control system technology for the NPPs in Korea has been optimized to maximize the operability as well as the safety through the design, construction, start-up and operation experiences. Both Shin-Kori Units 1 and 2 and Shin-Wolsong Units 1 and 2 NPP projects under construction are being progressed at the same time. Digital Plant Control Systems of these projects have adopted multi-loop controllers, redundant loop configuration, and soft control system for the radwaste system. Programmable Logic Controller (PLC) and Distributed Control System (DCS) are applied with soft control system in Shin-Kori Units 3 and 4. This paper describes the evolvement of control system at the NPPs in Korea and the experience and design improvement through the observation of the latest failure of the digital control system. In addition, design concept and its trend of the digital control system being applied to the NPP in Korea are introduced. (authors)« less

Description and theory of operation of the computer by-pass system for the NASA F-8 digital fly-by-wire control system

NASA Technical Reports Server (NTRS)

1978-01-01

A triplex digital flight control system was installed in a NASA F-8C airplane to provide fail operate, full authority control. The triplex digital computers and interface circuitry process the pilot commands and aircraft motion feedback parameters according to the selected control laws, and they output the surface commands as an analog signal to the servoelectronics for position control of the aircraft's power actuators. The system and theory of operation of the computer by pass and servoelectronics are described and an automated ground test for each axis is included.

Wind energy system time-domain (WEST) analyzers

NASA Technical Reports Server (NTRS)

Dreier, M. E.; Hoffman, J. A.

1981-01-01

A portable analyzer which simulates in real time the complex nonlinear dynamics of horizontal axis wind energy systems was constructed. Math models for an aeroelastic rotor featuring nonlinear aerodynamic and inertial terms were implemented with high speed digital controllers and analog calculation. This model was combined with other math models of elastic supports, control systems, a power train and gimballed rotor kinematics. A stroboscopic display system graphically depicting distributed blade loads, motion, and other aerodynamic functions on a cathode ray tube is included. Limited correlation efforts showed good comparison between the results of this analyzer and other sophisticated digital simulations. The digital simulation results were successfully correlated with test data.

A 64-channel ultra-low power system-on-chip for local field and action potentials recording

NASA Astrophysics Data System (ADS)

Rodríguez-Pérez, Alberto; Delgado-Restituto, Manuel; Darie, Angela; Soto-Sánchez, Cristina; Fernández-Jover, Eduardo; Rodríguez-Vázquez, Ángel

2015-06-01

This paper reports an integrated 64-channel neural recording sensor. Neural signals are acquired, filtered, digitized and compressed in the channels. Additionally, each channel implements an auto-calibration mechanism which configures the transfer characteristics of the recording site. The system has two transmission modes; in one case the information captured by the channels is sent as uncompressed raw data; in the other, feature vectors extracted from the detected neural spikes are released. Data streams coming from the channels are serialized by an embedded digital processor. Experimental results, including in vivo measurements, show that the power consumption of the complete system is lower than 330μW.

The Wireless Data Acquisition System for the Vibration Table

NASA Astrophysics Data System (ADS)

Teng, Y. T.; Hu, X.

2014-12-01

The vibration table is a large-scaled tool used for inspecting the performance of seismometers. The output from a seismometer on the table can be directly monitored when the vibration table moves in certain pattern. Compared with other inspection methods, inspecting seismometers' performance indicators (frequency response, degree of linearity, sensitivity, lateral inhibition and dynamic range etc). using vibration tables is more intuitive. Therefore, the vibration tables are an essential testing part in developing new seismometers and seismometer quality control. Whereas, in practice, a cable is needed to connect the seismometer to the ground equipments for its signal outputs and power supply, that means adding a time-varying nonlinear spring between the vibration table and ground. The cable adds nonlinear feature to the table, distorts the table-board movement and bring extra errors to the inspecting work and affected the testing accuracy and precision. In face of this problem, we developed a wireless acquiring system for the vibration table. The system is consisted of a three-channel analog-to-digital conversion, an acquisition control part, local data storage, network interface, wireless router and power management, etc. The analog-to-digital conversion part uses a 24-digit high-precision converter, which has a programmable amplifier at the front end of its artificial circuit, with the function of matching outputs with different amplifier from the vibration table. The acquisition control part uses a 32 bit ARM processor, with low-power dissipation, minute extension and high performance. The application software platform is written in Linux to make the system convenient for multitasking work. Large volume local digital storage is achieved by a 32G SD card, which is used for saving real time acquired data. Data transmission is achieved by network interface and wireless router, which can simplify the application software by the supported TCP/IP protocol. Besides, the acquisition system uses built-in power supply, which provides power to the system with Li-On rechargeable battery with high capacity, then all the cable link between the vibration table and the ground equipment have been removed. With all these changes, the whole system is immobilized on board of the vibration table after being packaged.

Microcomputer Applications in Power and Propulsion Systems.

DTIC Science & Technology

1981-03-01

WAKERLY John "Error detecting codes self-checking circuits and applications ". The computer science library - NORTH HOLLAND NY A1 9-t FULL AUTHORITY DIGITAL...7 AD-A09 267 ADVISORY GROUP FOR AEROSPACE RESEARCH AND DEVELOPMENT-ETC F/6 9/2 MAR 81ICROCONPUTER APPLICATIONS IN POWER AND PROPULSION SYSTEMS.(U...SERIES No. 113 Microcomputer Applications in Power and Propulsion Systems This document has been approved for public releasea and sale, ift

Hybrid inverter for HVDC/weak AC system interconnection

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

Tam, K.S.

1985-01-01

The concept of the hybrid converter is introduced. By independently controlling a naturally commutated converter (NCC) and an artificially commutated converter (ACC), real power and reactive power can be controlled independently. Alternatively, the ac bus voltage can be regulated without affecting the real power transfer. Independent control is feasible only within certain operating boundaries. Twelve pulse operation, sequential control, and complementary circuits may be viewed as variations of the hybrid converter. The concept of the hybrid converter is demonstrated by digital simulation. At the current state of technology, the NCC is best implemented by a 6-pulse bridge using thyristors asmore » the switching elements. A survey of power electronics applicable to HVDC applications reveals that the capacitively commutated current-sourced converters are either technically or economically better than the other alternatives for the implementation of the ACC. The digital simulation results show that the problems of operating an HVDC system into a weak ac system can be solved by using a hybrid inverter. A new control scheme, the zero Q control, is developed. With no reactive power interaction between the dc system and the ac system, the stability of the HVDC/weak ac system operation is significantly improved. System start-up and fault recovery is fast and stable.« less

Time of flight system on a chip

NASA Technical Reports Server (NTRS)

Paschalidis, Nicholas P. (Inventor)

2006-01-01

A CMOS time-of-flight TOF system-on-a-chip SoC for precise time interval measurement with low power consumption and high counting rate has been developed. The analog and digital TOF chip may include two Constant Fraction Discriminators CFDs and a Time-to-Digital Converter TDC. The CFDs can interface to start and stop anodes through two preamplifiers and perform signal processing for time walk compensation (110). The TDC digitizes the time difference with reference to an off-chip precise external clock (114). One TOF output is an 11-bit digital word and a valid event trigger output indicating a valid event on the 11-bit output bus (116).

Results and Insights on the Impact of Smoke on Digital Instrumentation and Control

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

Tanaka, T. J.; Nowlen, S. P.

2001-01-31

Smoke can cause interruptions and upsets in active electronics. Because nuclear power plants are replacing analog with digital instrumentation and control systems, qualification guidelines for new systems are being reviewed for severe environments such as smoke and electromagnetic interference. Active digital systems, individual components, and active circuits have been exposed to smoke in a program sponsored by the U.S. Nuclear Regulatory Commission. The circuits and systems were all monitored during the smoke exposure, indicating any immediate effects of the smoke. The major effect of smoke has been to increase leakage currents (through circuit bridging across contacts and leads) and tomore » cause momentary upsets and failures in digital systems. This report summarizes two previous reports and presents new results from conformal coating, memory chip, and hard drive tests. The report describes practices for mitigation of smoke damage through digital system design, fire barriers, ventilation, fire suppressants, and post fire procedures.« less

A system-level view of optimizing high-channel-count wireless biosignal telemetry.

PubMed

Chandler, Rodney J; Gibson, Sarah; Karkare, Vaibhav; Farshchi, Shahin; Marković, Dejan; Judy, Jack W

2009-01-01

In this paper we perform a system-level analysis of a wireless biosignal telemetry system. We perform an analysis of each major system component (e.g., analog front end, analog-to-digital converter, digital signal processor, and wireless link), in which we consider physical, algorithmic, and design limitations. Since there are a wide range applications for wireless biosignal telemetry systems, each with their own unique set of requirements for key parameters (e.g., channel count, power dissipation, noise level, number of bits, etc.), our analysis is equally broad. The net result is a set of plots, in which the power dissipation for each component and as the system as a whole, are plotted as a function of the number of channels for different architectural strategies. These results are also compared to existing implementations of complete wireless biosignal telemetry systems.

47 CFR 74.785 - Low power TV digital data service pilot project.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 4 2011-10-01 2011-10-01 false Low power TV digital data service pilot project... Power TV, TV Translator, and TV Booster Stations § 74.785 Low power TV digital data service pilot project. Low power TV stations authorized pursuant to the LPTV Digital Data Services Act (Public Law 106...

47 CFR 74.785 - Low power TV digital data service pilot project.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 4 2010-10-01 2010-10-01 false Low power TV digital data service pilot project... Power TV, TV Translator, and TV Booster Stations § 74.785 Low power TV digital data service pilot project. Low power TV stations authorized pursuant to the LPTV Digital Data Services Act (Public Law 106...

Digital frequency offset-locked He–Ne laser system with high beat frequency stability, narrow optical linewidth and optical fibre output

NASA Astrophysics Data System (ADS)

Sternkopf, Christian; Manske, Eberhard

2018-06-01

We report on the enhancement of a previously-presented heterodyne laser source on the basis of two phase-locked loop (PLL) frequency coupled internal-mirror He–Ne lasers. Our new system consists of two digitally controlled He–Ne lasers with slightly different wavelengths, and offers high-frequency stability and very narrow optical linewidth. The digitally controlled system has been realized by using a FPGA controller and transconductance amplifiers. The light of both lasers was coupled into separate fibres for heterodyne interferometer applications. To enhance the laser performance we observed the sensitivity of both laser tubes to electromagnetic noise from various laser power supplies and frequency control systems. Furthermore, we describe how the linewidth of a frequency-controlled He–Ne laser can be reduced during precise frequency stabilisation. The digitally controlled laser source reaches a standard beat frequency deviation of less than 20 Hz (with 1 s gate time) and a spectral full width at half maximum (FWHM) of the beat signal less than 3 kHz. The laser source has enough optical output power to serve a fibre-coupled multi axis heterodyne interferometer. The system can be adjusted to output beat frequencies in the range of 0.1 MHz–20 MHz.

77 FR 50726 - Software Requirement Specifications for Digital Computer Software and Complex Electronics Used in...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-22

... Computer Software and Complex Electronics Used in Safety Systems of Nuclear Power Plants AGENCY: Nuclear...-1209, ``Software Requirement Specifications for Digital Computer Software and Complex Electronics used... Electronics Engineers (ANSI/IEEE) Standard 830-1998, ``IEEE Recommended Practice for Software Requirements...

76 FR 28819 - NUREG/CR-XXXX, Development of Quantitative Software Reliability Models for Digital Protection...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-18

... NUCLEAR REGULATORY COMMISSION [NRC-2011-0109] NUREG/CR-XXXX, Development of Quantitative Software..., ``Development of Quantitative Software Reliability Models for Digital Protection Systems of Nuclear Power Plants... of Risk Analysis, Office of Nuclear Regulatory Research, U.S. Nuclear Regulatory Commission...

Nuclear Science Symposium, 19th, and Nuclear Power Systems Symposium, 4th, Miami, Fla., December 6-8, 1972, Proceedings.

NASA Technical Reports Server (NTRS)

1973-01-01

Major topics covered include radiation monitoring instrumentation, nuclear circuits and systems, biomedical applications of nuclear radiation in diagnosis and therapy, plasma research for fusion power, reactor control and instrumentation, nuclear power standards, and applications of digital computers in nuclear power plants. Systems and devices for space applications are described, including the Apollo alpha spectrometer, a position sensitive detection system for UV and X-ray photons, a 4500-volt electron multiplier bias supply for satellite use, spark chamber systems, proportional counters, and other devices. Individual items are announced in this issue.

Digital Control Technologies for Modular DC-DC Converters

NASA Technical Reports Server (NTRS)

Button, Robert M.; Kascak, Peter E.; Lebron-Velilla, Ramon

2002-01-01

Recent trends in aerospace Power Management and Distribution (PMAD) systems focus on using commercial off-the-shelf (COTS) components as standard building blocks. This move to more modular designs has been driven by a desire to reduce costs and development times, but is also due to the impressive power density and efficiency numbers achieved by today's commercial DC-DC converters. However, the PMAD designer quickly learns of the hidden "costs" of using COTS converters. The most significant cost is the required addition of external input filters to meet strict electromagnetic interference (MIAMI) requirements for space systems. In fact, the high power density numbers achieved by the commercial manufacturers are greatly due to the lack of necessary input filters included in the COTS module. The NASA Glenn Research Center is currently pursuing a digital control technology that addresses this problem with modular DC-DC converters. This paper presents the digital control technologies that have been developed to greatly reduce the input filter requirements for paralleled, modular DC-DC converters. Initial test result show that the input filter's inductor size was reduced by 75 percent, and the capacitor size was reduced by 94 percent while maintaining the same power quality specifications.

Development Status of the NSTAR Ion Propulsion System Power Processor

NASA Technical Reports Server (NTRS)

Hamley, John A.; Pinero, Luis R.; Rawlin, Vincent K.; Miller, John R.; Cartier, Kevin C.; Bowers, Glen E.

1995-01-01

A 0.5-2.3 kW xenon ion propulsion system is presently being developed under the NASA Solar Electric Propulsion Technology Application Readiness (NSTAR) program. This propulsion system includes a 30 cm diameter xenon ion thruster, a Digital Control Interface Unit, a xenon feed system, and a power processing unit (PPU). The PPU consists of the power supply assemblies which operate the thruster neutralizer, main discharge chamber, and ion optics. Also included are recycle logic and a digital microcontroller. The neutralizer and discharge power supplies employ a dual use configuration which combines the functions of two power supplies into one, significantly simplifying the PPU. Further simplification was realized by implementing a single thruster control loop which regulates the beam current via the discharge current. Continuous throttling is possible over a 0.5-2.3 kW output power range. All three power supplies have been fabricated and tested with resistive loads, and have been combined into a single breadboard unit with the recycle logic and microcontroller. All line and load regulation test results show the power supplies to be within the NSTAR flight PPU specified power output of 1.98 kW. The overall efficiency of the PPU, calculated as the combined efficiencies of the power supplies and controller, at 2.3 kW delivered to resistive loads was 0.90. The component was 6.16 kg. Integration testing of the neutralizer and discharge power supplies with a functional model thruster revealed no issues with discharge ignition or steady state operation.

47 CFR 74.796 - Modification of digital transmission systems and analog transmission systems for digital operation.

Code of Federal Regulations, 2011 CFR

2011-10-01

...) Subtract the value determined in the previous step from the authorized effective radiated power (“ERP”) of... ERP must be expressed in decibels above one kilowatt: ERP(dBk) = 10 log ERP(kW); (4) Convert the ERP calculated in the previous step to units of kilowatts; and (5) The ERP value determined through the above...

Analyzing Small Signal Stability of Power System based on Online Data by Use of SMES

NASA Astrophysics Data System (ADS)

Ishikawa, Hiroyuki; Shirai, Yasuyuki; Nitta, Tanzo; Shibata, Katsuhiko

The purpose of this study is to estimate eigen-values and eigen-vectors of a power system from on-line data to evaluate the power system stability. Power system responses due to the small power modulation of known pattern from SMES (Superconducting Magnetic Energy Storage) were analyzed, and the transfer functions between the power modulation and power oscillations of generators were obtained. Eigen-values and eigen-vectors were estimated from the transfer functions. Experiments were carried out by use of a model SMES and Advanced Power System Analyzer (APSA), which is an analogue type power system simulator of Kansai Electric Power Company Inc., Japan. Changes in system condition were observed by the estimated eigen-values and eigen-vectors. Result agreed well with the resent report and digital simulation. This method gives a new application for SMES, which will be installed for improving electric power quality.

A Qualitative Assessment of Current CCF Guidance Based on a Review of Safety System Digital Implementation Changes with Evolving Technology

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

Korsah, Kofi; Muhlheim, Michael David; Wood, Richard

The US Nuclear Regulatory Commission (NRC) is initiating a new rulemaking project to develop a digital system common-cause failure (CCF) rule. This rulemaking will review and modify or affirm the NRC's current digital system CCF policy as discussed in the Staff Requirements Memorandum to the Secretary of the Commission, Office of the NRC (SECY) 93-087, Policy, Technical, and Licensing Issues Pertaining to Evolutionary and Advanced Light Water Reactor (ALWR) Designs, and Branch Technical Position (BTP) 7-19, Guidance on Evaluation of Defense-in-Depth and Diversity in Digital Computer-Based Instrumentation and Control Systems, as well as Chapter 7, Instrumentation and Controls, in NRCmore » Regulatory Guide (NUREG)-0800, Standard Review Plan for Review of Safety Analysis Reports for Nuclear Power Plants (ML033580677). The Oak Ridge National Laboratory (ORNL) is providing technical support to the NRC staff on the CCF rulemaking, and this report is one of several providing the technical basis to inform NRC staff members. For the task described in this report, ORNL examined instrumentation and controls (I&C) technology implementations in nuclear power plants in the light of current CCF guidance. The intent was to assess whether the current position on CCF is adequate given the evolutions in digital safety system implementations and, if gaps in the guidance were found, to provide recommendations as to how these gaps could be closed.« less

47 CFR 74.792 - Digital low power TV and TV translator station protected contour.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 4 2010-10-01 2010-10-01 false Digital low power TV and TV translator station... SERVICES Low Power TV, TV Translator, and TV Booster Stations § 74.792 Digital low power TV and TV translator station protected contour. (a) A digital low power TV or TV translator will be protected from...

47 CFR 74.793 - Digital low power TV and TV translator station protection of broadcast stations.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 4 2010-10-01 2010-10-01 false Digital low power TV and TV translator station... DISTRIBUTIONAL SERVICES Low Power TV, TV Translator, and TV Booster Stations § 74.793 Digital low power TV and TV translator station protection of broadcast stations. (a) An application to construct a new digital low power...

Power budget enhancement in NG-EPON system employing novel twisted-PAM4

NASA Astrophysics Data System (ADS)

Li, Longsheng; Bi, Meihua; Fu, Yan; Miao, Xin; Zhu, Qingming; Hu, Weisheng

2018-03-01

In this paper, we firstly design a novel modulation format named Twisted-PAM4 (T-PAM4) for the high-speed NG-EPON and the PON-based digital fronthaul system. Compared to other high-order modulation formats like 4-ary pulse amplitude modulation (PAM4), T-PAM4 provides two independent sampling values in each symbol period and enables two-dimensional symbol decision, which significantly improves the receiver sensitivity and hence enlarges the system power budget. Based on this advantage, six types of T-PAM4 are experimentally demonstrated in 28-Gb/s/ λ NG-PON and 32-Gb/s/ λ PON-based digital fronthaul system. The experimental results show that, compared to the ordinary PAM4, the T-PAM4 can bring 5-dB and 4-dB extra power budget in NG-EPON and PON-based fronthaul system respectively. In addition, by experiment, it is also depicted that the T-PAM4 is remarkably robust to system nonlinearity, which would ease the linearity requirement on system components and hence reduce system cost.

Design and implementation of Remote Digital Energy Meter (RDEM) based on GSM technology

NASA Astrophysics Data System (ADS)

Khan, Muhammad Waseem; Wang, Jie; Irfan, Muhammad; Shiraz, M.; Khan, Ali Hassan

2017-11-01

Electric power is one of the basic requirement for socio economic and social prosperity of any country, which is mainly employs for domestic, industrial and agricultural sectors. The primary purpose of this research is to design and implement an energy meter which can remotely control and monitor through global system for mobile (GSM) communication technology. For this purpose, a single phase or three phase digital energy meters are used to add on different advanced modules. The energy meter can be activated and display power consumption information at the consumer premises on liquid crystal display and through a short message service (SMS) by using GSM technology. At the power sending end, an energy meter can be remotely control and monitor through GSM technology without any system disturbances. This study will lead to make the system easier, economical, reliable and efficient for the electrical department.

A 6.45 μW Self-Powered SoC With Integrated Energy-Harvesting Power Management and ULP Asymmetric Radios for Portable Biomedical Systems.

PubMed

Roy, Abhishek; Klinefelter, Alicia; Yahya, Farah B; Chen, Xing; Gonzalez-Guerrero, Luisa Patricia; Lukas, Christopher J; Kamakshi, Divya Akella; Boley, James; Craig, Kyle; Faisal, Muhammad; Oh, Seunghyun; Roberts, Nathan E; Shakhsheer, Yousef; Shrivastava, Aatmesh; Vasudevan, Dilip P; Wentzloff, David D; Calhoun, Benton H

2015-12-01

This paper presents a batteryless system-on-chip (SoC) that operates off energy harvested from indoor solar cells and/or thermoelectric generators (TEGs) on the body. Fabricated in a commercial 0.13 μW process, this SoC sensing platform consists of an integrated energy harvesting and power management unit (EH-PMU) with maximum power point tracking, multiple sensing modalities, programmable core and a low power microcontroller with several hardware accelerators to enable energy-efficient digital signal processing, ultra-low-power (ULP) asymmetric radios for wireless transmission, and a 100 nW wake-up radio. The EH-PMU achieves a peak end-to-end efficiency of 75% delivering power to a 100 μA load. In an example motion detection application, the SoC reads data from an accelerometer through SPI, processes it, and sends it over the radio. The SPI and digital processing consume only 2.27 μW, while the integrated radio consumes 4.18 μW when transmitting at 187.5 kbps for a total of 6.45 μW.

Analysis of Even Harmonics Generation in an Isolated Electric Power System

NASA Astrophysics Data System (ADS)

Kanao, Norikazu; Hayashi, Yasuhiro; Matsuki, Junya

Harmonics bred from loads are mainly odd order because the current waveform has half-wave symmetry. Since the even harmonics are negligibly small, those are not generally measured in electric power systems. However, even harmonics were measured at a 500/275/154kV substation in Hokuriku Electric Power Company after removal of a transmission line fault. The even harmonics caused malfunctions of protective digital relays because the relays used 4th harmonics at the input filter as automatic supervisory signal. This paper describes the mechanism of generation of the even harmonics by comparing measured waveforms with ATP-EMTP simulation results. As a result of analysis, it is cleared that even harmonics are generated by three causes. The first cause is a magnetizing current of transformers due to flux deviation by DC component of a fault current. The second one is due to harmonic conversion of a synchronous machine which generates even harmonics when direct current component or even harmonic current flow into the machine. The third one is that increase of harmonic impedance due to an isolated power system produces harmonic voltages. The design of the input filter of protective digital relays should consider even harmonics generation in an isolated power system.

Method and apparatus for spur-reduced digital sinusoid synthesis

NASA Technical Reports Server (NTRS)

Zimmerman, George A. (Inventor); Flanagan, Michael J. (Inventor)

1995-01-01

A technique for reducing the spurious signal content in digital sinusoid synthesis is presented. Spur reduction is accomplished through dithering both amplitude and phase values prior to word-length reduction. The analytical approach developed for analog quantization is used to produce new bounds on spur performance in these dithered systems. Amplitude dithering allows output word-length reduction without introducing additional spurs. Effects of periodic dither similar to that produced by a pseudo-noise (PN) generator are analyzed. This phase dithering method provides a spur reduction of 6(M + 1) dB per phase bit when the dither consists of M uniform variates. While the spur reduction is at the expense of an increase in system noise, the noise power can be made white, making the power spectral density small. This technique permits the use of a smaller number of phase bits addressing sinusoid look-up tables, resulting in an exponential decrease in system complexity. Amplitude dithering allows the use of less complicated multipliers and narrower data paths in purely digital applications, as well as the use of coarse-resolution, highly-linear digital-to-analog converters (DAC's) to obtain spur performance limited by the DAC linearity rather than its resolution.

Real time implementation and control validation of the wind energy conversion system

NASA Astrophysics Data System (ADS)

Sattar, Adnan

The purpose of the thesis is to analyze dynamic and transient characteristics of wind energy conversion systems including the stability issues in real time environment using the Real Time Digital Simulator (RTDS). There are different power system simulation tools available in the market. Real time digital simulator (RTDS) is one of the powerful tools among those. RTDS simulator has a Graphical User Interface called RSCAD which contains detail component model library for both power system and control relevant analysis. The hardware is based upon the digital signal processors mounted in the racks. RTDS simulator has the advantage of interfacing the real world signals from the external devices, hence used to test the protection and control system equipments. Dynamic and transient characteristics of the fixed and variable speed wind turbine generating systems (WTGSs) are analyzed, in this thesis. Static Synchronous Compensator (STATCOM) as a flexible ac transmission system (FACTS) device is used to enhance the fault ride through (FRT) capability of the fixed speed wind farm. Two level voltage source converter based STATCOM is modeled in both VSC small time-step and VSC large time-step of RTDS. The simulation results of the RTDS model system are compared with the off-line EMTP software i.e. PSCAD/EMTDC. A new operational scheme for a MW class grid-connected variable speed wind turbine driven permanent magnet synchronous generator (VSWT-PMSG) is developed. VSWT-PMSG uses fully controlled frequency converters for the grid interfacing and thus have the ability to control the real and reactive powers simultaneously. Frequency converters are modeled in the VSC small time-step of the RTDS and three phase realistic grid is adopted with RSCAD simulation through the use of optical analogue digital converter (OADC) card of the RTDS. Steady state and LVRT characteristics are carried out to validate the proposed operational scheme. Simulation results show good agreement with real time simulation software and thus can be used to validate the controllers for the real time operation. Integration of the Battery Energy Storage System (BESS) with wind farm can smoothen its intermittent power fluctuations. The work also focuses on the real time implementation of the Sodium Sulfur (NaS) type BESS. BESS is integrated with the STATCOM. The main advantage of this system is that it can also provide the reactive power support to the system along with the real power exchange from BESS unit. BESS integrated with STATCOM is modeled in the VSC small time-step of the RTDS. The cascaded vector control scheme is used for the control of the STATCOM and suitable control is developed to control the charging/discharging of the NaS type BESS. Results are compared with Laboratory standard power system software PSCAD/EMTDC and the advantages of using RTDS in dynamic and transient characteristics analyses of wind farm are also demonstrated clearly.

Image processing for a tactile/vision substitution system using digital CNN.

PubMed

Lin, Chien-Nan; Yu, Sung-Nien; Hu, Jin-Cheng

2006-01-01

In view of the parallel processing and easy implementation properties of CNN, we propose to use digital CNN as the image processor of a tactile/vision substitution system (TVSS). The digital CNN processor is used to execute the wavelet down-sampling filtering and the half-toning operations, aiming to extract important features from the images. A template combination method is used to embed the two image processing functions into a single CNN processor. The digital CNN processor is implemented on an intellectual property (IP) and is implemented on a XILINX VIRTEX II 2000 FPGA board. Experiments are designated to test the capability of the CNN processor in the recognition of characters and human subjects in different environments. The experiments demonstrates impressive results, which proves the proposed digital CNN processor a powerful component in the design of efficient tactile/vision substitution systems for the visually impaired people.

An accurate system for onsite calibration of electronic transformers with digital output.

PubMed

Zhi, Zhang; Li, Hong-Bin

2012-06-01

Calibration systems with digital output are used to replace conventional calibration systems because of principle diversity and characteristics of digital output of electronic transformers. But precision and unpredictable stability limit their onsite application even development. So fully considering the factors influencing accuracy of calibration system and employing simple but reliable structure, an all-digital calibration system with digital output is proposed in this paper. In complicated calibration environments, precision and dynamic range are guaranteed by A/D converter with 24-bit resolution, synchronization error limit is nanosecond by using the novelty synchronization method. In addition, an error correction algorithm based on the differential method by using two-order Hanning convolution window has good inhibition of frequency fluctuation and inter-harmonics interference. To verify the effectiveness, error calibration was carried out in the State Grid Electric Power Research Institute of China and results show that the proposed system can reach the precision class up to 0.05. Actual onsite calibration shows that the system has high accuracy, and is easy to operate with satisfactory stability.

An accurate system for onsite calibration of electronic transformers with digital output

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

Zhi Zhang; Li Hongbin; State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Wuhan 430074

Calibration systems with digital output are used to replace conventional calibration systems because of principle diversity and characteristics of digital output of electronic transformers. But precision and unpredictable stability limit their onsite application even development. So fully considering the factors influencing accuracy of calibration system and employing simple but reliable structure, an all-digital calibration system with digital output is proposed in this paper. In complicated calibration environments, precision and dynamic range are guaranteed by A/D converter with 24-bit resolution, synchronization error limit is nanosecond by using the novelty synchronization method. In addition, an error correction algorithm based on the differentialmore » method by using two-order Hanning convolution window has good inhibition of frequency fluctuation and inter-harmonics interference. To verify the effectiveness, error calibration was carried out in the State Grid Electric Power Research Institute of China and results show that the proposed system can reach the precision class up to 0.05. Actual onsite calibration shows that the system has high accuracy, and is easy to operate with satisfactory stability.« less

An accurate system for onsite calibration of electronic transformers with digital output

NASA Astrophysics Data System (ADS)

Zhi, Zhang; Li, Hong-Bin

2012-06-01

Calibration systems with digital output are used to replace conventional calibration systems because of principle diversity and characteristics of digital output of electronic transformers. But precision and unpredictable stability limit their onsite application even development. So fully considering the factors influencing accuracy of calibration system and employing simple but reliable structure, an all-digital calibration system with digital output is proposed in this paper. In complicated calibration environments, precision and dynamic range are guaranteed by A/D converter with 24-bit resolution, synchronization error limit is nanosecond by using the novelty synchronization method. In addition, an error correction algorithm based on the differential method by using two-order Hanning convolution window has good inhibition of frequency fluctuation and inter-harmonics interference. To verify the effectiveness, error calibration was carried out in the State Grid Electric Power Research Institute of China and results show that the proposed system can reach the precision class up to 0.05. Actual onsite calibration shows that the system has high accuracy, and is easy to operate with satisfactory stability.

High-performance dual-speed CCD camera system for scientific imaging

NASA Astrophysics Data System (ADS)

Simpson, Raymond W.

1996-03-01

Traditionally, scientific camera systems were partitioned with a `camera head' containing the CCD and its support circuitry and a camera controller, which provided analog to digital conversion, timing, control, computer interfacing, and power. A new, unitized high performance scientific CCD camera with dual speed readout at 1 X 106 or 5 X 106 pixels per second, 12 bit digital gray scale, high performance thermoelectric cooling, and built in composite video output is described. This camera provides all digital, analog, and cooling functions in a single compact unit. The new system incorporates the A/C converter, timing, control and computer interfacing in the camera, with the power supply remaining a separate remote unit. A 100 Mbyte/second serial link transfers data over copper or fiber media to a variety of host computers, including Sun, SGI, SCSI, PCI, EISA, and Apple Macintosh. Having all the digital and analog functions in the camera made it possible to modify this system for the Woods Hole Oceanographic Institution for use on a remote controlled submersible vehicle. The oceanographic version achieves 16 bit dynamic range at 1.5 X 105 pixels/second, can be operated at depths of 3 kilometers, and transfers data to the surface via a real time fiber optic link.

Performance improvement of coherent free-space optical communication with quadrature phase-shift keying modulation using digital phase estimation.

PubMed

Li, Xueliang; Geng, Tianwen; Ma, Shuang; Li, Yatian; Gao, Shijie; Wu, Zhiyong

2017-06-01

The performance of coherent free-space optical (CFSO) communication with phase modulation is limited by both phase fluctuations and intensity scintillations induced by atmospheric turbulence. To improve the system performance, one effective way is to use digital phase estimation. In this paper, a CFSO communication system with quadrature phase-shift keying modulation is studied. With consideration of the effects of log-normal amplitude fluctuations and Gauss phase fluctuations, a two-stage Mth power carrier phase estimation (CPE) scheme is proposed. The simulation results show that the phase noise can be suppressed greatly by this scheme, and the system symbol error rate performance with the two-stage Mth power CPE can be three orders lower than that of the single-stage Mth power CPE. Therefore, the two-stage CPE we proposed can contribute to the performance improvements of the CFSO communication system and has determinate guidance sense to its actual application.

47 CFR 74.792 - Digital low power TV and TV translator station protected contour.

Code of Federal Regulations, 2013 CFR

2013-10-01

... SERVICES Low Power TV, TV Translator, and TV Booster Stations § 74.792 Digital low power TV and TV... interference from other low power TV, TV translator, Class A TV or TV booster stations or digital low power TV...

47 CFR 74.792 - Digital low power TV and TV translator station protected contour.

Code of Federal Regulations, 2011 CFR

2011-10-01

... SERVICES Low Power TV, TV Translator, and TV Booster Stations § 74.792 Digital low power TV and TV... interference from other low power TV, TV translator, Class A TV or TV booster stations or digital low power TV...

47 CFR 74.792 - Digital low power TV and TV translator station protected contour.

Code of Federal Regulations, 2014 CFR

2014-10-01

... SERVICES Low Power TV, TV Translator, and TV Booster Stations § 74.792 Digital low power TV and TV... interference from other low power TV, TV translator, Class A TV or TV booster stations or digital low power TV...

47 CFR 74.792 - Digital low power TV and TV translator station protected contour.

Code of Federal Regulations, 2012 CFR

2012-10-01

... SERVICES Low Power TV, TV Translator, and TV Booster Stations § 74.792 Digital low power TV and TV... interference from other low power TV, TV translator, Class A TV or TV booster stations or digital low power TV...

Advanced reliability modeling of fault-tolerant computer-based systems

NASA Technical Reports Server (NTRS)

Bavuso, S. J.

1982-01-01

Two methodologies for the reliability assessment of fault tolerant digital computer based systems are discussed. The computer-aided reliability estimation 3 (CARE 3) and gate logic software simulation (GLOSS) are assessment technologies that were developed to mitigate a serious weakness in the design and evaluation process of ultrareliable digital systems. The weak link is based on the unavailability of a sufficiently powerful modeling technique for comparing the stochastic attributes of one system against others. Some of the more interesting attributes are reliability, system survival, safety, and mission success.

Hybrid techniques for the digital control of mechanical and optical systems

NASA Astrophysics Data System (ADS)

Acernese, Fausto; Barone, Fabrizio; De Rosa, Rosario; Eleuteri, Antonio; Milano, Leopoldo; Pardi, Silvio; Ricciardi, Iolanda; Russo, Guido

2004-07-01

One of the main requirements of a digital system for the control of interferometric detectors of gravitational waves is the computing power, that is a direct consequence of the increasing complexity of the digital algorithms necessary for the control signals generation. For this specific task many specialised non standard real-time architectures have been developed, often very expensive and difficult to upgrade. On the other hand, such computing power is generally fully available for off-line applications on standard Pc based systems. Therefore, a possible and obvious solution may be provided by the integration of both the the real-time and off-line architecture resulting in a hybrid control system architecture based on standards available components, trying to get both the advantages of the perfect data synchronization provided by the real-time systems and by the large computing power available on Pc based systems. Such integration may be provided by the implementation of the link between the two different architectures through the standard Ethernet network, whose data transfer speed is largely increasing in these years, using the TCP/IP and UDP protocols. In this paper we describe the architecture of an hybrid Ethernet based real-time control system protoype we implemented in Napoli, discussing its characteristics and performances. Finally we discuss a possible application to the real-time control of a suspended mass of the mode cleaner of the 3m prototype optical interferometer for gravitational wave detection (IDGW-3P) operational in Napoli.

An Ultra-Low Power Charge Redistribution Successive Approximation Register A/D Converter for Biomedical Applications.

PubMed

Koppa, Santosh; Mohandesi, Manouchehr; John, Eugene

2016-12-01

Power consumption is one of the key design constraints in biomedical devices such as pacemakers that are powered by small non rechargeable batteries over their entire life time. In these systems, Analog to Digital Convertors (ADCs) are used as interface between analog world and digital domain and play a key role. In this paper we present the design of an 8-bit Charge Redistribution Successive Approximation Register (CR-SAR) analog to digital converter in standard TSMC 0.18μm CMOS technology for low power and low data rate devices such as pacemakers. The 8-bit optimized CR-SAR ADC achieves low power of less than 250nW with conversion rate of 1KB/s. This ADC achieves integral nonlinearity (INL) and differential nonlinearity (DNL) less than 0.22 least significant bit (LSB) and less than 0.04 LSB respectively as compared to the standard requirement for the INL and DNL errors to be less than 0.5 LSB. The designed ADC operates at 1V supply voltage converting input ranging from 0V to 250mV.

Arkansas 50m Wind Power Class

Science.gov Websites

Geospatial_Data_Presentation_Form: vector digital data Other_Citation_Details: The wind power resource estimates were produced by AWS TrueWind using their MesoMap system and historical weather data under contract to Wind Powering America/NREL. This map has been validated with available surface data by NREL and wind energy

Integration of image capture and processing: beyond single-chip digital camera

NASA Astrophysics Data System (ADS)

Lim, SukHwan; El Gamal, Abbas

2001-05-01

An important trend in the design of digital cameras is the integration of capture and processing onto a single CMOS chip. Although integrating the components of a digital camera system onto a single chip significantly reduces system size and power, it does not fully exploit the potential advantages of integration. We argue that a key advantage of integration is the ability to exploit the high speed imaging capability of CMOS image senor to enable new applications such as multiple capture for enhancing dynamic range and to improve the performance of existing applications such as optical flow estimation. Conventional digital cameras operate at low frame rates and it would be too costly, if not infeasible, to operate their chips at high frame rates. Integration solves this problem. The idea is to capture images at much higher frame rates than he standard frame rate, process the high frame rate data on chip, and output the video sequence and the application specific data at standard frame rate. This idea is applied to optical flow estimation, where significant performance improvements are demonstrate over methods using standard frame rate sequences. We then investigate the constraints on memory size and processing power that can be integrated with a CMOS image sensor in a 0.18 micrometers process and below. We show that enough memory and processing power can be integrated to be able to not only perform the functions of a conventional camera system but also to perform applications such as real time optical flow estimation.

A multi-channel low-power system-on-chip for single-unit recording and narrowband wireless transmission of neural signal.

PubMed

Bonfanti, A; Ceravolo, M; Zambra, G; Gusmeroli, R; Spinelli, A S; Lacaita, A L; Angotzi, G N; Baranauskas, G; Fadiga, L

2010-01-01

This paper reports a multi-channel neural recording system-on-chip (SoC) with digital data compression and wireless telemetry. The circuit consists of a 16 amplifiers, an analog time division multiplexer, an 8-bit SAR AD converter, a digital signal processor (DSP) and a wireless narrowband 400-MHz binary FSK transmitter. Even though only 16 amplifiers are present in our current die version, the whole system is designed to work with 64 channels demonstrating the feasibility of a digital processing and narrowband wireless transmission of 64 neural recording channels. A digital data compression, based on the detection of action potentials and storage of correspondent waveforms, allows the use of a 1.25-Mbit/s binary FSK wireless transmission. This moderate bit-rate and a low frequency deviation, Manchester-coded modulation are crucial for exploiting a narrowband wireless link and an efficient embeddable antenna. The chip is realized in a 0.35- εm CMOS process with a power consumption of 105 εW per channel (269 εW per channel with an extended transmission range of 4 m) and an area of 3.1 × 2.7 mm(2). The transmitted signal is captured by a digital TV tuner and demodulated by a wideband phase-locked loop (PLL), and then sent to a PC via an FPGA module. The system has been tested for electrical specifications and its functionality verified in in-vivo neural recording experiments.

Innovating Education and Educating for Innovation: The Power of Digital Technologies and Skills

ERIC Educational Resources Information Center

OECD Publishing, 2016

2016-01-01

OECD's Innovation Strategy calls upon all sectors in the economy and society to innovate in order to foster productivity, growth and well-being. Education systems are critically important for innovation through the development of skills that nurture new ideas and technologies. However, whereas digital technologies are profoundly changing the way…

"Digit Anatomy": A New Technique for Learning Anatomy Using Motor Memory

ERIC Educational Resources Information Center

Oh, Chang-Seok; Won, Hyung-Sun; Kim, Kyong-Jee; Jang, Dong-Su

2011-01-01

Gestural motions of the hands and fingers are powerful tools for expressing meanings and concepts, and the nervous system has the capacity to retain multiple long-term motor memories, especially including movements of the hands. We developed many sets of successive movements of both hands, referred to as "digit anatomy," and made…

Digital Baseband Architecture For Transponder

NASA Technical Reports Server (NTRS)

Nguyen, Tien M.; Yeh, Hen-Geul

1995-01-01

Proposed advanced transponder for long-distance radio communication system with turnaround ranging contains carrier-signal-tracking loop including baseband digital "front end." For reduced cost, transponder includes analog intermediate-frequency (IF) section and analog automatic gain control (AGC) loop at first of two IF mixers. However, second IF mixer redesigned to ease digitization of baseband functions. To conserve power and provide for simpler and smaller transponder hardware, baseband digital signal-processing circuits designed to implement undersampling scheme. Furthermore, sampling scheme and sampling frequency chosen so redesign involves minimum modification of command-detector unit (CDU).

Preliminary design of an auxiliary power unit for the space shuttle. Volume 4: Selected system supporting studies

NASA Technical Reports Server (NTRS)

Hamilton, M. L.; Burriss, W. L.

1972-01-01

Selected system supporting analyses in conjunction with the preliminary design of an auxiliary power unit (APU) for the space shuttle are presented. Both steady state and transient auxiliary power unit performance, based on digital computer programs, were examined. The selected APU provides up to 400 horsepower out of the gearbox, weighs 227 pounds, and requires 2 pounds per shaft horsepower hour of propellants.

CEA SMAD 2016 Digitizer Evaluation.

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

Merchant, Bion J.

Sandia National Laboratories has tested and evaluated an updated SMAD digitizer, developed by the French Alternative Energies and Atomic Energy Commission (CEA). The SMAD digitizers are intended to record sensor output for seismic and infrasound monitoring applications. The purpose of this digitizer evaluation is to measure the performance characteristics in such areas as power consumption, input impedance, sensitivity, full scale, self-noise, dynamic range, system noise, response, passband, and timing. The SMAD digitizers have been updated since their last evaluation by Sandia to improve their performance when recording at a sample rate of 20 Hz for infrasound applications and 100 Hzmore » for hydro-acoustic seismic stations. This evaluation focuses primarily on the 20 Hz and 100 Hz sample rates. The SMAD digitizers are being evaluated for potential use in the International Monitoring System (IMS) of the Comprehensive Nuclear Test- Ban-Treaty Organization (CTBTO).« less

Development of small and inexpensive digital data acquisition systems using a microcontroller-based approach†

PubMed Central

Naivar, Mark A.; Wilder, Mark E.; Habbersett, Robert C.; Woods, Travis A.; Sebba, David S.; Nolan, John P.; Graves, Steven W.

2014-01-01

Fully digital data acquisition systems for use in flow cytometry provide excellent flexibility and precision. Here, we demonstrate the development of a low cost, small, and low power digital flow cytometry data acquisition system using a single microcontroller chip with an integrated analog to digital converter (ADC). Our demonstration system uses a commercially available evaluation board making the system simple to integrate into a flow cytometer. We have evaluated this system using calibration microspheres analyzed on commercial, slow-flow, and CCD based flow cytometers. In our evaluations, our demonstration data system clearly resolves all eight peaks of a Rainbow microsphere set on both a slow-flow flow cytometer and a retrofitted BD FACScalibur, which indicates it has the sensitivity and resolution required for most flow cytometry applications. It is also capable of millisecond time resolution, full waveform collection, and selective triggering of data collection from a CCD camera. The capability of our demonstration system suggests that the use of microcontrollers for flow cytometry digital data-acquisition will be increasingly valuable for extending the life of older cytometers and provides a compelling data-system design approach for low-cost, portable flow cytometers. PMID:19852060

Development of small and inexpensive digital data acquisition systems using a microcontroller-based approach.

PubMed

Naivar, Mark A; Wilder, Mark E; Habbersett, Robert C; Woods, Travis A; Sebba, David S; Nolan, John P; Graves, Steven W

2009-12-01

Fully digital data acquisition systems for use in flow cytometry provide excellent flexibility and precision. Here, we demonstrate the development of a low cost, small, and low power digital flow cytometry data acquisition system using a single microcontroller chip with an integrated analog to digital converter (ADC). Our demonstration system uses a commercially available evaluation board making the system simple to integrate into a flow cytometer. We have evaluated this system using calibration microspheres analyzed on commercial, slow-flow, and CCD-based flow cytometers. In our evaluations, our demonstration data system clearly resolves all eight peaks of a Rainbow microsphere set on both a slow-flow flow cytometer and a retrofitted BD FACScalibur, which indicates it has the sensitivity and resolution required for most flow cytometry applications. It is also capable of millisecond time resolution, full waveform collection, and selective triggering of data collection from a CCD camera. The capability of our demonstration system suggests that the use of microcontrollers for flow cytometry digital data-acquisition will be increasingly valuable for extending the life of older cytometers and provides a compelling data-system design approach for low-cost, portable flow cytometers.

Solar-Powered Airplane with Cameras and WLAN

NASA Technical Reports Server (NTRS)

Higgins, Robert G.; Dunagan, Steve E.; Sullivan, Don; Slye, Robert; Brass, James; Leung, Joe G.; Gallmeyer, Bruce; Aoyagi, Michio; Wei, Mei Y.; Herwitz, Stanley R.;

LIBS data analysis using a predictor-corrector based digital signal processor algorithm

NASA Astrophysics Data System (ADS)

Sanders, Alex; Griffin, Steven T.; Robinson, Aaron

2012-06-01

There are many accepted sensor technologies for generating spectra for material classification. Once the spectra are generated, communication bandwidth limitations favor local material classification with its attendant reduction in data transfer rates and power consumption. Transferring sensor technologies such as Cavity Ring-Down Spectroscopy (CRDS) and Laser Induced Breakdown Spectroscopy (LIBS) require effective material classifiers. A result of recent efforts has been emphasis on Partial Least Squares - Discriminant Analysis (PLS-DA) and Principle Component Analysis (PCA). Implementation of these via general purpose computers is difficult in small portable sensor configurations. This paper addresses the creation of a low mass, low power, robust hardware spectra classifier for a limited set of predetermined materials in an atmospheric matrix. Crucial to this is the incorporation of PCA or PLS-DA classifiers into a predictor-corrector style implementation. The system configuration guarantees rapid convergence. Software running on multi-core Digital Signal Processor (DSPs) simulates a stream-lined plasma physics model estimator, reducing Analog-to-Digital (ADC) power requirements. This paper presents the results of a predictorcorrector model implemented on a low power multi-core DSP to perform substance classification. This configuration emphasizes the hardware system and software design via a predictor corrector model that simultaneously decreases the sample rate while performing the classification.

Intelligent Systems for Power Management and Distribution

NASA Technical Reports Server (NTRS)

Button, Robert M.

2002-01-01

The motivation behind an advanced technology program to develop intelligent power management and distribution (PMAD) systems is described. The program concentrates on developing digital control and distributed processing algorithms for PMAD components and systems to improve their size, weight, efficiency, and reliability. Specific areas of research in developing intelligent DC-DC converters and distributed switchgear are described. Results from recent development efforts are presented along with expected future benefits to the overall PMAD system performance.

Geographically distributed real-time digital simulations using linear prediction

DOE PAGES

Liu, Ren; Mohanpurkar, Manish; Panwar, Mayank; ...

2016-07-04

Real time simulation is a powerful tool for analyzing, planning, and operating modern power systems. For analyzing the ever evolving power systems and understanding complex dynamic and transient interactions larger real time computation capabilities are essential. These facilities are interspersed all over the globe and to leverage unique facilities geographically-distributed real-time co-simulation in analyzing the power systems is pursued and presented. However, the communication latency between different simulator locations may lead to inaccuracy in geographically distributed real-time co-simulations. In this paper, the effect of communication latency on geographically distributed real-time co-simulation is introduced and discussed. In order to reduce themore » effect of the communication latency, a real-time data predictor, based on linear curve fitting is developed and integrated into the distributed real-time co-simulation. Two digital real time simulators are used to perform dynamic and transient co-simulations with communication latency and predictor. Results demonstrate the effect of the communication latency and the performance of the real-time data predictor to compensate it.« less

Geographically distributed real-time digital simulations using linear prediction

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

Liu, Ren; Mohanpurkar, Manish; Panwar, Mayank

Real time simulation is a powerful tool for analyzing, planning, and operating modern power systems. For analyzing the ever evolving power systems and understanding complex dynamic and transient interactions larger real time computation capabilities are essential. These facilities are interspersed all over the globe and to leverage unique facilities geographically-distributed real-time co-simulation in analyzing the power systems is pursued and presented. However, the communication latency between different simulator locations may lead to inaccuracy in geographically distributed real-time co-simulations. In this paper, the effect of communication latency on geographically distributed real-time co-simulation is introduced and discussed. In order to reduce themore » effect of the communication latency, a real-time data predictor, based on linear curve fitting is developed and integrated into the distributed real-time co-simulation. Two digital real time simulators are used to perform dynamic and transient co-simulations with communication latency and predictor. Results demonstrate the effect of the communication latency and the performance of the real-time data predictor to compensate it.« less

A Study of Synchronization Techniques for Optical Communication Systems

NASA Technical Reports Server (NTRS)

Gagliardi, R. M.

1975-01-01

The study of synchronization techniques and related topics in the design of high data rate, deep space, optical communication systems was reported. Data cover: (1) effects of timing errors in narrow pulsed digital optical systems, (2) accuracy of microwave timing systems operating in low powered optical systems, (3) development of improved tracking systems for the optical channel and determination of their tracking performance, (4) development of usable photodetector mathematical models for application to analysis and performance design in communication receivers, and (5) study application of multi-level block encoding to optical transmission of digital data.

An ultra low-power front-end IC for wearable health monitoring system.

PubMed

Yu-Pin Hsu; Zemin Liu; Hella, Mona M

2016-08-01

This paper presents a low-power front-end IC for wearable health monitoring systems. The IC, designed in a standard 0.13μm CMOS technology, fully integrates a low-noise analog front-end (AFE) to process the weak bio-signals, followed by an analog-to-digital converter (ADC) to digitize the extracted signals. An AC-coupled driving buffer, that interfaces between the AFE and the ADC is introduced to scale down the power supply of the ADC. The power consumption decreases by 50% compared to the case without power supply scaling. The AFE passes signals from 0.5Hz to 280Hz and from 0.7Hz to 160Hz with a simulated input referred noise of 1.6μVrms and achieves a maximum gain of 35dB/41dB respectively, with a noise-efficiency factor (NEF) of the AFE is 1. The 8-bit ADC achieves a simulated 7.96-bit resolution at 10KS/s sampling rate under 0.5V supply voltage. The overall system consumes only 0.86μW at dual supply voltages of 1V (AFE) and 0.5 V (ADC).

Digitally switchable multi-focal lens using freeform optics.

PubMed

Wang, Xuan; Qin, Yi; Hua, Hong; Lee, Yun-Han; Wu, Shin-Tson

2018-04-16

Optical technologies offering electrically tunable optical power have found a broad range of applications, from head-mounted displays for virtual and augmented reality applications to microscopy. In this paper, we present a novel design and prototype of a digitally switchable multi-focal lens (MFL) that offers the capability of rapidly switching the optical power of the system among multiple foci. It consists of a freeform singlet and a customized programmable optical shutter array (POSA). Time-multiplexed multiple foci can be obtained by electrically controlling the POSA to switch the light path through different segments of the freeform singlet rapidly. While this method can be applied to a broad range of imaging and display systems, we experimentally demonstrate a proof-of-concept prototype for a multi-foci imaging system.

Detecting Cyber Attacks On Nuclear Power Plants

NASA Astrophysics Data System (ADS)

Rrushi, Julian; Campbell, Roy

This paper proposes an unconventional anomaly detection approach that provides digital instrumentation and control (I&C) systems in a nuclear power plant (NPP) with the capability to probabilistically discern between legitimate protocol frames and attack frames. The stochastic activity network (SAN) formalism is used to model the fusion of protocol activity in each digital I&C system and the operation of physical components of an NPP. SAN models are employed to analyze links between protocol frames as streams of bytes, their semantics in terms of NPP operations, control data as stored in the memory of I&C systems, the operations of I&C systems on NPP components, and NPP processes. Reward rates and impulse rewards are defined in the SAN models based on the activity-marking reward structure to estimate NPP operation profiles. These profiles are then used to probabilistically estimate the legitimacy of the semantics and payloads of protocol frames received by I&C systems.

Application of low-power, high-rate PCM telemetry in a helicopter instrumentation system

NASA Technical Reports Server (NTRS)

Thomas, Mitchel E.; Diamond, John K.

1987-01-01

The use of low-power, high-rate pulse code modulation (PCM) in a helicopter instrumentation system is examined. A Helicopter Instrumentation and Recording System (HIARS) was developed to obtain main rotor blade measurements and fuselage performance measurements. The HIARS consists of a low-power PCM telemeter, a digital PCM system, an optical rotor position sensor, and a PCM decommutation unit; the components and functions of these subsystems are described. Flight tests were conducted to evaluate the ability of the HIARS to measure aircraft parameters. The test data reveal that the PCM telemetry is applicable to helicopter instrumentation systems.

Invited Article: Digital beam-forming imaging riometer systems

NASA Astrophysics Data System (ADS)

Honary, Farideh; Marple, Steve R.; Barratt, Keith; Chapman, Peter; Grill, Martin; Nielsen, Erling

2011-03-01

The design and operation of a new generation of digital imaging riometer systems developed by Lancaster University are presented. In the heart of the digital imaging riometer is a field-programmable gate array (FPGA), which is used for the digital signal processing and digital beam forming, completely replacing the analog Butler matrices which have been used in previous designs. The reconfigurable nature of the FPGA has been exploited to produce tools for remote system testing and diagnosis which have proven extremely useful for operation in remote locations such as the Arctic and Antarctic. Different FPGA programs enable different instrument configurations, including a 4 × 4 antenna filled array (producing 4 × 4 beams), an 8 × 8 antenna filled array (producing 7 × 7 beams), and a Mills cross system utilizing 63 antennas producing 556 usable beams. The concept of using a Mills cross antenna array for riometry has been successfully demonstrated for the first time. The digital beam forming has been validated by comparing the received signal power from cosmic radio sources with results predicted from the theoretical beam radiation pattern. The performances of four digital imaging riometer systems are compared against each other and a traditional imaging riometer utilizing analog Butler matrices. The comparison shows that digital imaging riometer systems, with independent receivers for each antenna, can obtain much better measurement precision for filled arrays or much higher spatial resolution for the Mills cross configuration when compared to existing imaging riometer systems.

Power feasibility of implantable digital spike-sorting circuits for neural prosthetic systems.

PubMed

Zumsteg, Zachary S; Ahmed, Rizwan E; Santhanam, Gopal; Shenoy, Krishna V; Meng, Teresa H

2004-01-01

A new class of neural prosthetic systems aims to assist disabled patients by translating cortical neural activity into control signals for prosthetic devices. Based on the success of proof-of-concept systems in the laboratory, there is now considerable interest in increasing system performance and creating implantable electronics for use in clinical systems. A critical question that impacts system performance and the overall architecture of these systems is whether it is possible to identify the neural source of each action potential (spike sorting) in real-time and with low power. Low power is essential both for power supply considerations and heat dissipation in the brain. In this paper we report that several state-of-the-art spike sorting algorithms implemented in modern CMOS VLSI processes are expected to be power realistic.

A rotor-mounted digital instrumentation system for helicopter blade flight research measurements

NASA Technical Reports Server (NTRS)

Knight, V. H., Jr.; Haywood, W. S., Jr.; Williams, M. L.

1978-01-01

A rotor mounted flight instrumentation system developed for helicopter rotor blade research is described. The system utilizes high speed digital techniques to acquire research data from miniature pressure transducers on advanced rotor airfoils which are flight tested on an AH-1G helicopter. The system employs microelectronic pulse code modulation (PCM) multiplexer digitizer stations located remotely on the blade and in a hub mounted metal canister. As many as 25 sensors can be remotely digitized by a 2.5 mm thick electronics package mounted on the blade near the tip to reduce blade wiring. The electronics contained in the canister digitizes up to 16 sensors, formats these data with serial PCM data from the remote stations, and transmits the data from the canister which is above the plane of the rotor. Data are transmitted over an RF link to the ground for real time monitoring and to the helicopter fuselage for tape recording. The complete system is powered by batteries located in the canister and requires no slip rings on the rotor shaft.

Design and implementation of a reconfigurable mixed-signal SoC based on field programmable analog arrays

NASA Astrophysics Data System (ADS)

Liu, Lintao; Gao, Yuhan; Deng, Jun

2017-11-01

This work presents a reconfigurable mixed-signal system-on-chip (SoC), which integrates switched-capacitor-based field programmable analog arrays (FPAA), analog-to-digital converter (ADC), digital-to-analog converter, digital down converter , digital up converter, 32-bit reduced instruction-set computer central processing unit (CPU) and other digital IPs on a single chip with 0.18 μm CMOS technology. The FPAA intellectual property could be reconfigured as different function circuits, such as gain amplifier, divider, sine generator, and so on. This single-chip integrated mixed-signal system is a complete modern signal processing system, occupying a die area of 7 × 8 mm 2 and consuming 719 mW with a clock frequency of 150 MHz for CPU and 200 MHz for ADC/DAC. This SoC chip can help customers to shorten design cycles, save board area, reduce the system power consumption and depress the system integration risk, which would afford a big prospect of application for wireless communication. Project supported by the National High Technology and Development Program of China (No. 2012AA012303).

The Effect of a Constant Level Lighting Control System on Small Offices With Windows

DTIC Science & Technology

1992-01-01

Scientific 2101 Digital Power Analyzer. The power factor was calculated by dividing the real power by the apparent power (current multiplied by voltage...CBNSC-TT-P 22060 INSODM - Cb. huad. Div. Delace Tockslcol to. C 2M30 US Arm Bo~kuau Disvriaw Pt Dalvoir VA 22M6 AWN: DTIC-AB (2) ATTN: Libary (41) ATmN

Taxonomy for Common-Cause Failure Vulnerability and Mitigation

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

Wood, Richard Thomas; Korsah, Kofi; Mullens, James Allen

2015-09-01

Applying current guidance and practices for common-cause failure (CCF) mitigation to digital instrumentation and control (I&C) systems has proven problematic, and the regulatory environment has been unpredictable. The potential for CCF vulnerability inhibits I&C modernization, thereby challenging the long-term sustainability of existing plants. For new plants and advanced reactor concepts, concern about CCF vulnerability in highly integrated digital I&C systems imposes a design burden that results in higher costs and increased complexity. The regulatory uncertainty in determining which mitigation strategies will be acceptable (e.g., what diversity is needed and how much is sufficient) drives designers to adopt complicated, costly solutionsmore » devised for existing plants. To address the conditions that constrain the transition to digital I&C technology by the US nuclear industry, crosscutting research is needed to resolve uncertainty, demonstrate necessary characteristics, and establish an objective basis for qualification of digital technology for nuclear power plant (NPP) I&C applications. To fulfill this research need, Oak Ridge National Laboratory is investigating mitigation of CCF vulnerability for nuclear-qualified applications. The outcome of this research is expected to contribute to a fundamentally sound, comprehensive basis to qualify digital technology for nuclear power applications. This report documents the development of a CCF taxonomy. The basis for the CCF taxonomy was generated by determining consistent terminology and establishing a classification approach. The terminology is based on definitions from standards, guides, and relevant nuclear power industry technical reports. The classification approach is derived from identified classification schemes focused on I&C systems and key characteristics, including failure modes. The CCF taxonomy provides the basis for a systematic organization of key systems aspects relevant to analyzing the potential for CCF vulnerability and the suitability of mitigation techniques. Development of an effective CCF taxonomy will help to provide a framework for establishing the objective analysis and assessment capabilities desired to facilitate rigorous identification of fault types and triggers that are the fundamental elements of CCF.« less

76 FR 61358 - Information Collections Being Submitted for Review and Approval to the Office of Management and...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-04

... Digital Low Power Television Translator, and Television Booster Stations and to Amend Rules for Digital...'') to transition from analog to digital broadcasting and states that low power television, TV translator...; Section 74.788; Low Power Television, TV Translator and Class A Television Digital Transition...

Dynamic modeling of brushless dc motor-power conditioner unit for electromechanical actuator application

NASA Technical Reports Server (NTRS)

Demerdash, N. A.; Nehl, T. W.

1979-01-01

A comprehensive digital model for the analysis of the dynamic-instantaneous performance of a power conditioner fed samarium-cobalt permanent magnet brushless DC motor is presented. The particular power conditioner-machine system at hand, for which this model was developed, is a component of an actual prototype electromechanical actuator built for NASA-JSC as a possible alternative to hydraulic actuators as part of feasibility studies for the shuttle orbiter applications. Excellent correlation between digital simulated and experimentally obtained performance data was achieved for this specific prototype. This is reported on in this paper. Details of one component of the model, its applications and the corresponding results are given in this paper.

LANDSAT-D flight segment operations manual, volume 1

NASA Technical Reports Server (NTRS)

Varhola, J.

1982-01-01

Hardware, systems, and subsystems for the multimission modular spacecraft used for LANDSAT 4 are described and depicted in block diagrams and schematics. Components discussed include the modular attitude control system; the communication and data handling subsystem; the narrowband tape recorder; the on-board computer; the propulsion module subsystem; the signal conditioning and control unit; the modular power subsystem; the solar array drive and power transmission assembly; the power distribution unit; the digital processing unit; and the wideband communication subsystem.

47 CFR 74.710 - Digital low power TV and TV translator station protection.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 4 2010-10-01 2010-10-01 false Digital low power TV and TV translator station... SERVICES Low Power TV, TV Translator, and TV Booster Stations § 74.710 Digital low power TV and TV translator station protection. (a) An application to construct a new low power TV, TV translator, or TV...

Power to the People: End-User Building of Digital Library Collections.

ERIC Educational Resources Information Center

Witten, Ian H.; Bainbridge, David; Boddie, Stefan J.

Digital library systems focus principally on the reader: the consumer of the material that constitutes the library. In contrast, this paper describes an interface that makes it easy for people to build their own library collections. Collections may be built and served locally from the user's own Web server, or (given appropriate permissions)…

The payload/shuttle-data-communication-link handbook

NASA Technical Reports Server (NTRS)

1982-01-01

Communication links between the Orbiter, payloads, and ground are described: end-to-end, hardline, S-band, Ku-band, TDRSS relay, waveforms, premodulation, subcarrier modulation, carrier modulation, transmitter power, antennas, the RF channel, system noise, received signal-to-noise spectral density, carrier-tracking loop, carrier demodulation, subcarrier demodulation, digital data detection, digital data decoding, and tandem link considerations.

Ultra-low-power wearable biopotential sensor nodes.

PubMed

Yazicioglu, R F; Torfs, T; Penders, J; Romero, I; Kim, H; Merken, P; Gyselinckx, B; Yoo, H J; Van Hoof, C

2009-01-01

This paper discusses ultra-low-power wireless sensor nodes intended for wearable biopotential monitoring. Specific attention is given to mixed-signal design approaches and their impact on the overall system power dissipation. Examples of trade-offs in power dissipation between analog front-ends and digital signal processing are also given. It is shown how signal filtering can further reduce the internal power consumption of a node. Such power saving approaches are indispensable as real-life tests of custom wireless ECG patches reveal the need for artifact detection and correction. The power consumption of such additional features has to come from power savings elsewhere in the system as the overall power budget cannot increase.

Implementation of olfactory bulb glomerular-layer computations in a digital neurosynaptic core.

PubMed

Imam, Nabil; Cleland, Thomas A; Manohar, Rajit; Merolla, Paul A; Arthur, John V; Akopyan, Filipp; Modha, Dharmendra S

2012-01-01

We present a biomimetic system that captures essential functional properties of the glomerular layer of the mammalian olfactory bulb, specifically including its capacity to decorrelate similar odor representations without foreknowledge of the statistical distributions of analyte features. Our system is based on a digital neuromorphic chip consisting of 256 leaky-integrate-and-fire neurons, 1024 × 256 crossbar synapses, and address-event representation communication circuits. The neural circuits configured in the chip reflect established connections among mitral cells, periglomerular cells, external tufted cells, and superficial short-axon cells within the olfactory bulb, and accept input from convergent sets of sensors configured as olfactory sensory neurons. This configuration generates functional transformations comparable to those observed in the glomerular layer of the mammalian olfactory bulb. Our circuits, consuming only 45 pJ of active power per spike with a power supply of 0.85 V, can be used as the first stage of processing in low-power artificial chemical sensing devices inspired by natural olfactory systems.

Portable wireless neurofeedback system of EEG alpha rhythm enhances memory.

PubMed

Wei, Ting-Ying; Chang, Da-Wei; Liu, You-De; Liu, Chen-Wei; Young, Chung-Ping; Liang, Sheng-Fu; Shaw, Fu-Zen

2017-11-13

Effect of neurofeedback training (NFT) on enhancement of cognitive function or amelioration of clinical symptoms is inconclusive. The trainability of brain rhythm using a neurofeedback system is uncertainty because various experimental designs are used in previous studies. The current study aimed to develop a portable wireless NFT system for alpha rhythm and to validate effect of the NFT system on memory with a sham-controlled group. The proposed system contained an EEG signal analysis device and a smartphone with wireless Bluetooth low-energy technology. Instantaneous 1-s EEG power and contiguous 5-min EEG power throughout the training were developed as feedback information. The training performance and its progression were kept to boost usability of our device. Participants were blinded and randomly assigned into either the control group receiving random 4-Hz power or Alpha group receiving 8-12-Hz power. Working memory and episodic memory were assessed by the backward digital span task and word-pair task, respectively. The portable neurofeedback system had advantages of a tiny size and long-term recording and demonstrated trainability of alpha rhythm in terms of significant increase of power and duration of 8-12 Hz. Moreover, accuracies of the backward digital span task and word-pair task showed significant enhancement in the Alpha group after training compared to the control group. Our tiny portable device demonstrated success trainability of alpha rhythm and enhanced two kinds of memories. The present study suggest that the portable neurofeedback system provides an alternative intervention for memory enhancement.

Research on digital system design of nuclear power valve

NASA Astrophysics Data System (ADS)

Zhang, Xiaolong; Li, Yuan; Wang, Tao; Dai, Ye

2018-04-01

With the progress of China's nuclear power industry, nuclear power plant valve products is in a period of rapid development, high performance, low cost, short cycle of design requirements for nuclear power valve is proposed, so there is an urgent need for advanced digital design method and integrated design platform to provide technical support. Especially in the background of the nuclear power plant leakage in Japan, it is more practical to improve the design capability and product performance of the nuclear power valve. The finite element numerical analysis is a common and effective method for the development of nuclear power valves. Nuclear power valve has high safety, complexity of valve chamber and nonlinearity of seal joint surface. Therefore, it is urgent to establish accurate prediction models for earthquake prediction and seal failure to meet engineering accuracy and calculation conditions. In this paper, a general method of finite element modeling for nuclear power valve assembly and key components is presented, aiming at revealing the characteristics and rules of finite element modeling of nuclear power valves, and putting forward aprecision control strategy for finite element models for nuclear power valve characteristics analysis.

Engineering studies of vectorcardiographs in blood pressure measuring systems, appendix 1

NASA Technical Reports Server (NTRS)

Mark, R. G.

1975-01-01

A small, portable, relatively inexpensive computer system was developed for on-line use in clinical or laboratory situations. The system features an integrated hardware-software package that permits use of all peripherals, such as analog-to-digital converter, oscilloscope, plotter, digital bus, with an interpreter constructed around the BASIC programming language. The system is conceptually similar to the LINC system developed in 1962, but is more compact and powerful due to intervening advances in integrated circuit technology. A description of the hardware of the system was given. A reference manual, user manual, and programming guides were also presented. Finally, a stereo display system for vectorcardiograms was described.

Development of Gravity Acceleration Measurement Using Simple Harmonic Motion Pendulum Method Based on Digital Technology and Photogate Sensor

NASA Astrophysics Data System (ADS)

Yulkifli; Afandi, Zurian; Yohandri

2018-04-01

Development of gravitation acceleration measurement using simple harmonic motion pendulum method, digital technology and photogate sensor has been done. Digital technology is more practical and optimizes the time of experimentation. The pendulum method is a method of calculating the acceleration of gravity using a solid ball that connected to a rope attached to a stative pole. The pendulum is swung at a small angle resulted a simple harmonic motion. The measurement system consists of a power supply, Photogate sensors, Arduino pro mini and seven segments. The Arduino pro mini receives digital data from the photogate sensor and processes the digital data into the timing data of the pendulum oscillation. The calculation result of the pendulum oscillation time is displayed on seven segments. Based on measured data, the accuracy and precision of the experiment system are 98.76% and 99.81%, respectively. Based on experiment data, the system can be operated in physics experiment especially in determination of the gravity acceleration.

Exploration of operator method digital optical computers for application to NASA

NASA Technical Reports Server (NTRS)

1990-01-01

Digital optical computer design has been focused primarily towards parallel (single point-to-point interconnection) implementation. This architecture is compared to currently developing VHSIC systems. Using demonstrated multichannel acousto-optic devices, a figure of merit can be formulated. The focus is on a figure of merit termed Gate Interconnect Bandwidth Product (GIBP). Conventional parallel optical digital computer architecture demonstrates only marginal competitiveness at best when compared to projected semiconductor implements. Global, analog global, quasi-digital, and full digital interconnects are briefly examined as alternative to parallel digital computer architecture. Digital optical computing is becoming a very tough competitor to semiconductor technology since it can support a very high degree of three dimensional interconnect density and high degrees of Fan-In without capacitive loading effects at very low power consumption levels.

Computer study of emergency shutdowns of a 60-kilowatt reactor Brayton space power system

NASA Technical Reports Server (NTRS)

Tew, R. C.; Jefferies, K. S.

1974-01-01

A digital computer study of emergency shutdowns of a 60-kWe reactor Brayton power system was conducted. Malfunctions considered were (1) loss of reactor coolant flow, (2) loss of Brayton system gas flow, (3)turbine overspeed, and (4) a reactivity insertion error. Loss of reactor coolant flow was the most serious malfunction for the reactor. Methods for moderating the reactor transients due to this malfunction are considered.

76 FR 44821 - Digital Low Power Television, Television Translator, and Television Booster Stations and To Amend...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-27

...] Digital Low Power Television, Television Translator, and Television Booster Stations and To Amend Rules... this proceeding in order to allow a timely and successful completion of the low power television digital transition. Although Congress established a hard deadline of June 12, 2009 for full power stations...

Individuals on alert: digital epidemiology and the individualization of surveillance.

PubMed

Samerski, Silja

2018-06-14

This article examines how digital epidemiology and eHealth coalesce into a powerful health surveillance system that fundamentally changes present notions of body and health. In the age of Big Data and Quantified Self, the conceptual and practical distinctions between individual and population body, personal and public health, surveillance and health care are diminishing. Expanding on Armstrong's concept of "surveillance medicine" to "quantified self medicine" and drawing on my own research on the symbolic power of statistical constructs in medical encounters, this article explores the impact of digital health surveillance on people's perceptions, actions and subjectivities. It discusses the epistemic confusions and paradoxes produced by a health care system that increasingly treats patients as risk profiles and prompts them to do the same, namely to perceive and manage themselves as a bundle of health and security risks. Since these risks are necessarily constructed in reference to epidemiological data that postulate a statistical gaze, they also construct or make-up disembodied "individuals on alert".

A Hydraulic Blowdown Servo System For Launch Vehicle

NASA Astrophysics Data System (ADS)

Chen, Anping; Deng, Tao

2016-07-01

This paper introduced a hydraulic blowdown servo system developed for a solid launch vehicle of the family of Chinese Long March Vehicles. It's the thrust vector control (TVC) system for the first stage. This system is a cold gas blowdown hydraulic servo system and consist of gas vessel, hydraulic reservoir, servo actuator, digital control unit (DCU), electric explosion valve, and pressure regulator etc. A brief description of the main assemblies and characteristics follows. a) Gas vessel is a resin/carbon fiber composite over wrapped pressure vessel with a titanium liner, The volume of the vessel is about 30 liters. b) Hydraulic reservoir is a titanium alloy piston type reservoir with a magnetostrictive sensor as the fluid level indicator. The volume of the reservoir is about 30 liters. c) Servo actuator is a equal area linear piston actuator with a 2-stage low null leakage servo valve and a linear variable differential transducer (LVDT) feedback the piston position, Its stall force is about 120kN. d) Digital control unit (DCU) is a compact digital controller based on digital signal processor (DSP), and deployed dual redundant 1553B digital busses to communicate with the on board computer. e) Electric explosion valve is a normally closed valve to confine the high pressure helium gas. f) Pressure regulator is a spring-loaded poppet pressure valve, and regulates the gas pressure from about 60MPa to about 24MPa. g) The whole system is mounted in the aft skirt of the vehicle. h) This system delivers approximately 40kW hydraulic power, by contrast, the total mass is less than 190kg. the power mass ratio is about 0.21. Have finished the development and the system test. Bench and motor static firing tests verified that all of the performances have met the design requirements. This servo system is complaint to use of the solid launch vehicle.

Optimized linear motor and digital PID controller setup used in Mössbauer spectrometer

NASA Astrophysics Data System (ADS)

Kohout, Pavel; Kouřil, Lukáš; Navařík, Jakub; Novák, Petr; Pechoušek, Jiří

2014-10-01

Optimization of a linear motor and digital PID controller setup used in a Mössbauer spectrometer is presented. Velocity driving system with a digital PID feedback subsystem was developed in the LabVIEW graphical environment and deployed on the sbRIO real-time hardware device (National Instruments). The most important data acquisition processes are performed as real-time deterministic tasks on an FPGA chip. Velocity transducer of a double loudspeaker type with a power amplifier circuit is driven by the system. Series of calibration measurements were proceeded to find the optimal setup of the P, I, D parameters together with velocity error signal analysis. The shape and given signal characteristics of the velocity error signal are analyzed in details. Remote applications for controlling and monitoring the PID system from computer or smart phone, respectively, were also developed. The best setup and P, I, D parameters were set and calibration spectrum of α-Fe sample with an average nonlinearity of the velocity scale below 0.08% was collected. Furthermore, the width of the spectral line below 0.30 mm/s was observed. Powerful and complex velocity driving system was designed.

Advanced Control Systems for Aircraft Powerplants

DTIC Science & Technology

1980-02-01

production of high- integrity software. 1.0 INTRODUCTION Work on full-authority digital control for gas turbines was started at Rolls- Royce Limited... INTRODUCTION In order to fully understand the operation of the Secondary Power System Control Unit - abbreviated SPSCU - we must first take a close look at...Only Memory EPROM -- Erasable Read Only Memory PLA -- Power Lever Angle LVDT -- Linear Variable Differential Transformer INTRODUCTION Preliminary design

Digital Architecture – Results From a Gap Analysis

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

Oxstrand, Johanna Helene; Thomas, Kenneth David; Fitzgerald, Kirk

The digital architecture is defined as a collection of IT capabilities needed to support and integrate a wide-spectrum of real-time digital capabilities for nuclear power plant performance improvements. The digital architecture can be thought of as an integration of the separate I&C and information systems already in place in NPPs, brought together for the purpose of creating new levels of automation in NPP work activities. In some cases, it might be an extension of the current communication systems, to provide digital communications where they are currently analog only. This collection of IT capabilities must in turn be based on amore » set of user requirements that must be supported for the interconnected technologies to operate in an integrated manner. These requirements, simply put, are a statement of what sorts of digital work functions will be exercised in a fully-implemented seamless digital environment and how much they will be used. The goal of the digital architecture research is to develop a methodology for mapping nuclear power plant operational and support activities into the digital architecture, which includes the development of a consensus model for advanced information and control architecture. The consensus model should be developed at a level of detail that is useful to the industry. In other words, not so detailed that it specifies specific protocols and not so vague that it is only provides a high level description of technology. The next step towards the model development is to determine the current state of digital architecture at typical NPPs. To investigate the current state, the researchers conducted a gap analysis to determine to what extent the NPPs can support the future digital technology environment with their existing I&C and IT structure, and where gaps exist with respect to the full deployment of technology over time. The methodology, result, and conclusions from the gap analysis are described in this report.« less

Design and Development of Amplitude and phase measurement of RF signal with Digital I-Q Demodulator

NASA Astrophysics Data System (ADS)

Soni, Dipal; Rajnish, Kumar; Verma, Sriprakash; Patel, Hriday; Trivedi, Rajesh; Mukherjee, Aparajita

2017-04-01

ITER-India, working as a nodal agency from India for ITER project [1], is responsible to deliver one of the packages, called Ion Cyclotron Heating & Current Drive (ICH&CD) - Radio Frequency Power Sources (RFPS). RFPS is having two cascaded amplifier chains (10 kW, 130 kW & 1.5 MW) combined to get 2.5 MW RF power output. Directional couplers are inserted at the output of each stage to extract forward power and reflected power as samples for measurement of amplitude and phase. Using passive mixer, forward power and reflected power are down converted to 1MHz Intermediate frequency (IF). This IF signal is used as an input to the Digital IQ Demodulator (DIQDM). DIQDM is realized using National Instruments make PXI hardware & LabVIEW software tool. In this paper, Amplitude and Phase measurement of RF signal with DIQDM technique is described. Also test results with dummy signals and signal generated from low power RF systems is discussed here.

System-Level Design of a 64-Channel Low Power Neural Spike Recording Sensor.

PubMed

Delgado-Restituto, Manuel; Rodriguez-Perez, Alberto; Darie, Angela; Soto-Sanchez, Cristina; Fernandez-Jover, Eduardo; Rodriguez-Vazquez, Angel

2017-04-01

This paper reports an integrated 64-channel neural spike recording sensor, together with all the circuitry to process and configure the channels, process the neural data, transmit via a wireless link the information and receive the required instructions. Neural signals are acquired, filtered, digitized and compressed in the channels. Additionally, each channel implements an auto-calibration algorithm which individually configures the transfer characteristics of the recording site. The system has two transmission modes; in one case the information captured by the channels is sent as uncompressed raw data; in the other, feature vectors extracted from the detected neural spikes are released. Data streams coming from the channels are serialized by the embedded digital processor. Experimental results, including in vivo measurements, show that the power consumption of the complete system is lower than 330 μW.

Reliability of digital reactor protection system based on extenics.

PubMed

Zhao, Jing; He, Ya-Nan; Gu, Peng-Fei; Chen, Wei-Hua; Gao, Feng

2016-01-01

After the Fukushima nuclear accident, safety of nuclear power plants (NPPs) is widespread concerned. The reliability of reactor protection system (RPS) is directly related to the safety of NPPs, however, it is difficult to accurately evaluate the reliability of digital RPS. The method is based on estimating probability has some uncertainties, which can not reflect the reliability status of RPS dynamically and support the maintenance and troubleshooting. In this paper, the reliability quantitative analysis method based on extenics is proposed for the digital RPS (safety-critical), by which the relationship between the reliability and response time of RPS is constructed. The reliability of the RPS for CPR1000 NPP is modeled and analyzed by the proposed method as an example. The results show that the proposed method is capable to estimate the RPS reliability effectively and provide support to maintenance and troubleshooting of digital RPS system.

Investigations of DC power supplies with optoelectronic transducers and RF energy converters

NASA Astrophysics Data System (ADS)

Guzowski, B.; Gozdur, R.; Bernacki, L.; Lakomski, M.

2016-04-01

Fiber Distribution Cabinets (FDC) monitoring systems are increasingly popular. However it is difficult to realize such system in passive FDC, due to lack of source of power supply. In this paper investigation of four different DC power supplies with optoelectronic transducers is described. Two converters: photovoltaic power converter and PIN photodiode can convert the light transmitted through the optical fiber to electric energy. Solar cell and antenna RF-PCB are also tested. Results presented in this paper clearly demonstrate that it is possible to build monitoring system in passive FDC. During the tests maximum obtained output power was 11 mW. However all converters provided enough power to excite 32-bit microcontroller with ARM-cores and digital thermometer.

Rotorcraft digital advanced avionics system (RODAAS) functional description

NASA Technical Reports Server (NTRS)

Peterson, E. M.; Bailey, J.; Mcmanus, T. J.

1985-01-01

A functional design of a rotorcraft digital advanced avionics system (RODAAS) to transfer the technology developed for general aviation in the Demonstration Advanced Avionics System (DAAS) program to rotorcraft operation was undertaken. The objective was to develop an integrated avionics system design that enhances rotorcraft single pilot IFR operations without increasing the required pilot training/experience by exploiting advanced technology in computers, busing, displays and integrated systems design. A key element of the avionics system is the functionally distributed architecture that has the potential for high reliability with low weight, power and cost. A functional description of the RODAAS hardware and software functions is presented.

Development of a microprocessor controller for stand-alone photovoltaic power systems

NASA Technical Reports Server (NTRS)

Millner, A. R.; Kaufman, D. L.

1984-01-01

A controller for stand-alone photovoltaic systems has been developed using a low power CMOS microprocessor. It performs battery state of charge estimation, array control, load management, instrumentation, automatic testing, and communications functions. Array control options are sequential subarray switching and maximum power control. A calculator keypad and LCD display provides manual control, fault diagnosis and digital multimeter functions. An RS-232 port provides data logging or remote control capability. A prototype 5 kW unit has been built and tested successfully. The controller is expected to be useful in village photovoltaic power systems, large solar water pumping installations, and other battery management applications.

DEAL annual report.

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

Misra, Shashank

2017-11-01

The digital electronics at the atomic limit (DEAL) project seeks to leverage Sandia's atomic-precision fabrication capability to realize the theorized orders-of-magnitude improvement in operating voltage for tunnel field effect transistors (TFETs) compared to CMOS. Not only are low-power digital circuits a critical element of many national security systems (e.g. satellites), TFETs can perform circuit functions inaccessible to CMOS (e.g. polymorphism).

It's Not All about the Music: Digital Goods, Social Media, and the Pressure of Peers

ERIC Educational Resources Information Center

Sopha, Matthew

2013-01-01

Social media offers a powerful platform for the independent digital content producer community to develop, disperse, and maintain their brands. In terms of information systems research, the broad majority of the work has not examined hedonic consumption on Social Media Sites (SMS). The focus has mostly been on the organizational perspectives and…

Highest integration in microelectronics: Development of digital ASICs for PARS3-LR

NASA Astrophysics Data System (ADS)

Scholler, Peter; Vonlutz, Rainer

Essential electronic system components by PARS3-LR, show high requirements in calculation power, power consumption and reliability, by immediately increasing integration thicknesses. These problems are solved by using integrated circuits, developed by LSI LOGIC, that uses the technical and economic advantages of this leading edge technology.

Digital micromirror based near-infrared illumination system for plasmonic photothermal neuromodulation.

PubMed

Jung, Hyunjun; Kang, Hongki; Nam, Yoonkey

2017-06-01

Light-mediated neuromodulation techniques provide great advantages to investigate neuroscience due to its high spatial and temporal resolution. To generate a spatial pattern of neural activity, it is necessary to develop a system for patterned-light illumination to a specific area. Digital micromirror device (DMD) based patterned illumination system have been used for neuromodulation due to its simple configuration and design flexibility. In this paper, we developed a patterned near-infrared (NIR) illumination system for region specific photothermal manipulation of neural activity using NIR-sensitive plasmonic gold nanorods (GNRs). The proposed system had high power transmission efficiency for delivering power density up to 19 W/mm 2 . We used a GNR-coated microelectrode array (MEA) to perform biological experiments using E18 rat hippocampal neurons and showed that it was possible to inhibit neural spiking activity of specific area in neural circuits with the patterned NIR illumination. This patterned NIR illumination system can serve as a promising neuromodulation tool to investigate neuroscience in a wide range of physiological and clinical applications.

Real-time simulation of a Doubly-Fed Induction Generator based wind power system on eMEGASimRTM Real-Time Digital Simulator

NASA Astrophysics Data System (ADS)

Boakye-Boateng, Nasir Abdulai

The growing demand for wind power integration into the generation mix prompts the need to subject these systems to stringent performance requirements. This study sought to identify the required tools and procedures needed to perform real-time simulation studies of Doubly-Fed Induction Generator (DFIG) based wind generation systems as basis for performing more practical tests of reliability and performance for both grid-connected and islanded wind generation systems. The author focused on developing a platform for wind generation studies and in addition, the author tested the performance of two DFIG models on the platform real-time simulation model; an average SimpowerSystemsRTM DFIG wind turbine, and a detailed DFIG based wind turbine using ARTEMiSRTM components. The platform model implemented here consists of a high voltage transmission system with four integrated wind farm models consisting in total of 65 DFIG based wind turbines and it was developed and tested on OPAL-RT's eMEGASimRTM Real-Time Digital Simulator.

A low-power and miniaturized electrocardiograph data collection system with smart textile electrodes for monitoring of cardiac function.

PubMed

Dai, Ming; Xiao, Xueliang; Chen, Xin; Lin, Haoming; Wu, Wanqing; Chen, Siping

2016-12-01

With the increasing aging population as well as health concerns, chronic heart disease has become the focus of public attention. A comfortable, low-powered, and wearable electrocardiogram (ECG) system for continuously monitoring the elderly's ECG signals over several hours is important for preventing cardiovascular diseases. Traditional ECG monitoring apparatus is often inconvenient to carry, has many electrodes to attach to the chest, and has a high-power consumption. There is also a challenge to design an electrocardiograph that satisfies requirements such as comfort, confinement, and compactness. Based on these considerations, this study presents a biosensor acquisition system for wearable, ubiquitous healthcare applications using three textile electrodes and a recording circuit specialized for ECG monitoring. In addition, several methods were adopted to reduce the power consumption of the device. The proposed system is composed of three parts: (1) an ECG analog front end (AFE), (2) digital signal processing and micro-control circuits, and (3) system software. Digital filter methods were used to eliminate the baseline wander, skin contact noise, and other interfering signals. A comparative study was conducted using this system to observe its performance with two commercial Holter monitors. The experimental results demonstrated that the total power consumption of this proposed system in a full round of ECG acquisition was only 29.74 mW. In addition, this low-power system performed well and stably measured the heart rate with an accuracy of 98.55 %. It can also contain a real-time dynamic display with organic light-emitting diodes (OLED) and wirelessly transmit information via a Bluetooth 4.0 module.

A Statistical Testing Approach for Quantifying Software Reliability; Application to an Example System

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

Chu, Tsong-Lun; Varuttamaseni, Athi; Baek, Joo-Seok

The U.S. Nuclear Regulatory Commission (NRC) encourages the use of probabilistic risk assessment (PRA) technology in all regulatory matters, to the extent supported by the state-of-the-art in PRA methods and data. Although much has been accomplished in the area of risk-informed regulation, risk assessment for digital systems has not been fully developed. The NRC established a plan for research on digital systems to identify and develop methods, analytical tools, and regulatory guidance for (1) including models of digital systems in the PRAs of nuclear power plants (NPPs), and (2) incorporating digital systems in the NRC's risk-informed licensing and oversight activities.more » Under NRC's sponsorship, Brookhaven National Laboratory (BNL) explored approaches for addressing the failures of digital instrumentation and control (I and C) systems in the current NPP PRA framework. Specific areas investigated included PRA modeling digital hardware, development of a philosophical basis for defining software failure, and identification of desirable attributes of quantitative software reliability methods. Based on the earlier research, statistical testing is considered a promising method for quantifying software reliability. This paper describes a statistical software testing approach for quantifying software reliability and applies it to the loop-operating control system (LOCS) of an experimental loop of the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL).« less

Benchmarking the performance of fixed-image receptor digital radiography systems. Part 2: system performance metric.

PubMed

Lee, Kam L; Bernardo, Michael; Ireland, Timothy A

2016-06-01

This is part two of a two-part study in benchmarking system performance of fixed digital radiographic systems. The study compares the system performance of seven fixed digital radiography systems based on quantitative metrics like modulation transfer function (sMTF), normalised noise power spectrum (sNNPS), detective quantum efficiency (sDQE) and entrance surface air kerma (ESAK). It was found that the most efficient image receptors (greatest sDQE) were not necessarily operating at the lowest ESAK. In part one of this study, sMTF is shown to depend on system configuration while sNNPS is shown to be relatively consistent across systems. Systems are ranked on their signal-to-noise ratio efficiency (sDQE) and their ESAK. Systems using the same equipment configuration do not necessarily have the same system performance. This implies radiographic practice at the site will have an impact on the overall system performance. In general, systems are more dose efficient at low dose settings.

Thin, nearly wireless adaptive optical device

NASA Technical Reports Server (NTRS)

Knowles, Gareth (Inventor); Hughes, Eli (Inventor)

2008-01-01

A thin, nearly wireless adaptive optical device capable of dynamically modulating the shape of a mirror in real time to compensate for atmospheric distortions and/or variations along an optical material is provided. The device includes an optical layer, a substrate, at least one electronic circuit layer with nearly wireless architecture, an array of actuators, power electronic switches, a reactive force element, and a digital controller. Actuators are aligned so that each axis of expansion and contraction intersects both substrate and reactive force element. Electronics layer with nearly wireless architecture, power electronic switches, and digital controller are provided within a thin-film substrate. The size and weight of the adaptive optical device is solely dominated by the size of the actuator elements rather than by the power distribution system.

Thin, nearly wireless adaptive optical device

NASA Technical Reports Server (NTRS)

Knowles, Gareth (Inventor); Hughes, Eli (Inventor)

2007-01-01

A thin, nearly wireless adaptive optical device capable of dynamically modulating the shape of a mirror in real time to compensate for atmospheric distortions and/or variations along an optical material is provided. The device includes an optical layer, a substrate, at least one electronic circuit layer with nearly wireless architecture, an array of actuators, power electronic switches, a reactive force element, and a digital controller. Actuators are aligned so that each axis of expansion and contraction intersects both substrate and reactive force element. Electronics layer with nearly wireless architecture, power electronic switches, and digital controller are provided within a thin-film substrate. The size and weight of the adaptive optical device is solely dominated by the size of the actuator elements rather than by the power distribution system.

Thin nearly wireless adaptive optical device

NASA Technical Reports Server (NTRS)

Knowles, Gareth J. (Inventor); Hughes, Eli (Inventor)

2009-01-01

A thin nearly wireless adaptive optical device capable of dynamically modulating the shape of a mirror in real time to compensate for atmospheric distortions and/or variations along an optical material is provided. The device includes an optical layer, a substrate, at least one electronic circuit layer with nearly wireless architecture, an array of actuators, power electronic switches, a reactive force element, and a digital controller. Actuators are aligned so that each axis of expansion and contraction intersects both substrate and reactive force element. Electronics layer with nearly wireless architecture, power electronic switches, and digital controller are provided within a thin-film substrate. The size and weight of the adaptive optical device is solely dominated by the size of the actuator elements rather than by the power distribution system.

Emulating a million machines to investigate botnets.

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

Rudish, Donald W.

2010-06-01

Researchers at Sandia National Laboratories in Livermore, California are creating what is in effect a vast digital petridish able to hold one million operating systems at once in an effort to study the behavior of rogue programs known as botnets. Botnets are used extensively by malicious computer hackers to steal computing power fron Internet-connected computers. The hackers harness the stolen resources into a scattered but powerful computer that can be used to send spam, execute phishing, scams or steal digital information. These remote-controlled 'distributed computers' are difficult to observe and track. Botnets may take over parts of tens of thousandsmore » or in some cases even millions of computers, making them among the world's most powerful computers for some applications.« less

A Self-Sustained Wireless Multi-Sensor Platform Integrated with Printable Organic Sensors for Indoor Environmental Monitoring

PubMed Central

Wu, Chun-Chang; Chuang, Wen-Yu; Wu, Ching-Da; Su, Yu-Cheng; Huang, Yung-Yang; Huang, Yang-Jing; Peng, Sheng-Yu; Yu, Shih-An; Lin, Chih-Ting; Lu, Shey-Shi

2017-01-01

A self-sustained multi-sensor platform for indoor environmental monitoring is proposed in this paper. To reduce the cost and power consumption of the sensing platform, in the developed platform, organic materials of PEDOT:PSS and PEDOT:PSS/EB-PANI are used as the sensing films for humidity and CO2 detection, respectively. Different from traditional gas sensors, these organic sensing films can operate at room temperature without heating processes or infrared transceivers so that the power consumption of the developed humidity and the CO2 sensors can be as low as 10 μW and 5 μW, respectively. To cooperate with these low-power sensors, a Complementary Metal-Oxide-Semiconductor (CMOS) system-on-chip (SoC) is designed to amplify and to read out multiple sensor signals with low power consumption. The developed SoC includes an analog-front-end interface circuit (AFE), an analog-to-digital convertor (ADC), a digital controller and a power management unit (PMU). Scheduled by the digital controller, the sensing circuits are power gated with a small duty-cycle to reduce the average power consumption to 3.2 μW. The designed PMU converts the power scavenged from a dye sensitized solar cell (DSSC) module into required supply voltages for SoC circuits operation under typical indoor illuminance conditions. To our knowledge, this is the first multiple environmental parameters (Temperature/CO2/Humidity) sensing platform that demonstrates a true self-powering functionality for long-term operations. PMID:28353680

A Self-Sustained Wireless Multi-Sensor Platform Integrated with Printable Organic Sensors for Indoor Environmental Monitoring.

PubMed

Wu, Chun-Chang; Chuang, Wen-Yu; Wu, Ching-Da; Su, Yu-Cheng; Huang, Yung-Yang; Huang, Yang-Jing; Peng, Sheng-Yu; Yu, Shih-An; Lin, Chih-Ting; Lu, Shey-Shi

2017-03-29

A self-sustained multi-sensor platform for indoor environmental monitoring is proposed in this paper. To reduce the cost and power consumption of the sensing platform, in the developed platform, organic materials of PEDOT:PSS and PEDOT:PSS/EB-PANI are used as the sensing films for humidity and CO₂ detection, respectively. Different from traditional gas sensors, these organic sensing films can operate at room temperature without heating processes or infrared transceivers so that the power consumption of the developed humidity and the CO₂ sensors can be as low as 10 μW and 5 μW, respectively. To cooperate with these low-power sensors, a Complementary Metal-Oxide-Semiconductor (CMOS) system-on-chip (SoC) is designed to amplify and to read out multiple sensor signals with low power consumption. The developed SoC includes an analog-front-end interface circuit (AFE), an analog-to-digital convertor (ADC), a digital controller and a power management unit (PMU). Scheduled by the digital controller, the sensing circuits are power gated with a small duty-cycle to reduce the average power consumption to 3.2 μW. The designed PMU converts the power scavenged from a dye sensitized solar cell (DSSC) module into required supply voltages for SoC circuits operation under typical indoor illuminance conditions. To our knowledge, this is the first multiple environmental parameters (Temperature/CO₂/Humidity) sensing platform that demonstrates a true self-powering functionality for long-term operations.

A configurable and low-power mixed signal SoC for portable ECG monitoring applications.

PubMed

Kim, Hyejung; Kim, Sunyoung; Van Helleputte, Nick; Artes, Antonio; Konijnenburg, Mario; Huisken, Jos; Van Hoof, Chris; Yazicioglu, Refet Firat

2014-04-01

This paper describes a mixed-signal ECG System-on-Chip (SoC) that is capable of implementing configurable functionality with low-power consumption for portable ECG monitoring applications. A low-voltage and high performance analog front-end extracts 3-channel ECG signals and single channel electrode-tissue-impedance (ETI) measurement with high signal quality. This can be used to evaluate the quality of the ECG measurement and to filter motion artifacts. A custom digital signal processor consisting of 4-way SIMD processor provides the configurability and advanced functionality like motion artifact removal and R peak detection. A built-in 12-bit analog-to-digital converter (ADC) is capable of adaptive sampling achieving a compression ratio of up to 7, and loop buffer integration reduces the power consumption for on-chip memory access. The SoC is implemented in 0.18 μm CMOS process and consumes 32 μ W from a 1.2 V while heart beat detection application is running, and integrated in a wireless ECG monitoring system with Bluetooth protocol. Thanks to the ECG SoC, the overall system power consumption can be reduced significantly.

Efficient high-performance ultrasound beamforming using oversampling

NASA Astrophysics Data System (ADS)

Freeman, Steven R.; Quick, Marshall K.; Morin, Marc A.; Anderson, R. C.; Desilets, Charles S.; Linnenbrink, Thomas E.; O'Donnell, Matthew

1998-05-01

High-performance and efficient beamforming circuitry is very important in large channel count clinical ultrasound systems. Current state-of-the-art digital systems using multi-bit analog to digital converters (A/Ds) have matured to provide exquisite image quality with moderate levels of integration. A simplified oversampling beamforming architecture has been proposed that may a low integration of delta-sigma A/Ds onto the same chip as digital delay and processing circuitry to form a monolithic ultrasound beamformer. Such a beamformer may enable low-power handheld scanners for high-end systems with very large channel count arrays. This paper presents an oversampling beamformer architecture that generates high-quality images using very simple; digitization, delay, and summing circuits. Additional performance may be obtained with this oversampled system for narrow bandwidth excitations by mixing the RF signal down in frequency to a range where the electronic signal to nose ratio of the delta-sigma A/D is optimized. An oversampled transmit beamformer uses the same delay circuits as receive and eliminates the need for separate transmit function generators.

Deep Cryogenic Low Power 24 Bits Analog to Digital Converter with Active Reverse Cryostat

NASA Astrophysics Data System (ADS)

Turqueti, Marcos; Prestemon, Soren; Albright, Robert

LBNL is developing an innovative data acquisition module for superconductive magnets where the front-end electronics and digitizer resides inside the cryostat. This electronic package allows conventional electronic technologies such as enhanced metal-oxide-semiconductor to work inside cryostats at temperatures as low as 4.2 K. This is achieved by careful management of heat inside the module that keeps the electronic envelop at approximately 85 K. This approach avoids all the difficulties that arise from changes in carrier mobility that occur in semiconductors at deep cryogenic temperatures. There are several advantages in utilizing this system. A significant reduction in electrical noise from signals captured inside the cryostat occurs due to the low temperature that the electronics is immersed in, reducing the thermal noise. The shorter distance that signals are transmitted before digitalization reduces pickup and cross-talk between channels. This improved performance in signal-to-noise rate by itself is a significant advantage. Another important advantage is the simplification of the feedthrough interface on the cryostat head. Data coming out of the cryostat is digital and serial, dramatically reducing the number of lines going through the cryostat feedthrough interface. It is important to notice that all lines coming out of the cryostat are digital and low voltage, reducing the possibility of electric breakdown inside the cryostat. This paper will explain in details the architecture and inner workings of this data acquisition system. It will also provide the performance of the analog to digital converter when the system is immersed in liquid helium, and in liquid nitrogen. Parameters such as power dissipation, integral non-linearity, effective number of bits, signal-to-noise and distortion, will be presented for both temperatures.

Deep Cryogenic Low Power 24 Bits Analog to Digital Converter with Active Reverse Cryostat

DOE PAGES

Turqueti, Marcos; Prestemon, Soren; Albright, Robert

2015-07-15

LBNL is developing an innovative data acquisition module for superconductive magnets where the front-end electronics and digitizer resides inside the cryostat. This electronic package allows conventional electronic technologies such as enhanced metal–oxide–semiconductor to work inside cryostats at temperatures as low as 4.2 K. This is achieved by careful management of heat inside the module that keeps the electronic envelop at approximately 85 K. This approach avoids all the difficulties that arise from changes in carrier mobility that occur in semiconductors at deep cryogenic temperatures. There are several advantages in utilizing this system. A significant reduction in electrical noise from signalsmore » captured inside the cryostat occurs due to the low temperature that the electronics is immersed in, reducing the thermal noise. The shorter distance that signals are transmitted before digitalization reduces pickup and cross-talk between channels. This improved performance in signal-to-noise rate by itself is a significant advantage. Another important advantage is the simplification of the feedthrough interface on the cryostat head. Data coming out of the cryostat is digital and serial, dramatically reducing the number of lines going through the cryostat feedthrough interface. It is important to notice that all lines coming out of the cryostat are digital and low voltage, reducing the possibility of electric breakdown inside the cryostat. This paper will explain in details the architecture and inner workings of this data acquisition system. It will also provide the performance of the analog to digital converter when the system is immersed in liquid helium, and in liquid nitrogen. Parameters such as power dissipation, integral non-linearity, effective number of bits, signal-to-noise and distortion, will be presented for both temperatures.« less

Application of Prognostic Health Management in Digital Electronic Systems

DTIC Science & Technology

2007-01-01

variable external supply applied the necessary core power to the processor while the motherboard continued to source power from the ATX supply. By...isolating the processor power from the motherboard power , control over the aging profile of the processor was achieved. Once nominal operating...Physics-of-failure RISC – Reduced Instruction Set Computer RUL – Remaining Useful Life 1 1-4244-0525-4/07/$20.00 ©2007 IEEE. Paper 1326

Synthetic aperture in terahertz in-line digital holography for resolution enhancement.

PubMed

Huang, Haochong; Rong, Lu; Wang, Dayong; Li, Weihua; Deng, Qinghua; Li, Bin; Wang, Yunxin; Zhan, Zhiqiang; Wang, Xuemin; Wu, Weidong

2016-01-20

Terahertz digital holography is a combination of terahertz technology and digital holography. In digital holography, the imaging resolution is the key parameter in determining the detailed quality of a reconstructed wavefront. In this paper, the synthetic aperture method is used in terahertz digital holography and the in-line arrangement is built to perform the detection. The resolved capability of previous terahertz digital holographic systems restricts this technique to meet the requirement of practical detection. In contrast, the experimental resolved power of the present method can reach 125 μm, which is the best resolution of terahertz digital holography to date. Furthermore, the basic detection of a biological specimen is conducted to show the practical application. In all, the results of the proposed method demonstrate the enhancement of experimental imaging resolution and that the amplitude and phase distributions of the fine structure of samples can be reconstructed by using terahertz digital holography.

A Wireless Capsule Endoscope System With Low-Power Controlling and Processing ASIC.

PubMed

Xinkai Chen; Xiaoyu Zhang; Linwei Zhang; Xiaowen Li; Nan Qi; Hanjun Jiang; Zhihua Wang

2009-02-01

This paper presents the design of a wireless capsule endoscope system. The proposed system is mainly composed of a CMOS image sensor, a RF transceiver and a low-power controlling and processing application specific integrated circuit (ASIC). Several design challenges involving system power reduction, system miniaturization and wireless wake-up method are resolved by employing optimized system architecture, integration of an area and power efficient image compression module, a power management unit (PMU) and a novel wireless wake-up subsystem with zero standby current in the ASIC design. The ASIC has been fabricated in 0.18-mum CMOS technology with a die area of 3.4 mm * 3.3 mm. The digital baseband can work under a power supply down to 0.95 V with a power dissipation of 1.3 mW. The prototype capsule based on the ASIC and a data recorder has been developed. Test result shows that proposed system architecture with local image compression lead to an average of 45% energy reduction for transmitting an image frame.

Optical information processing at NASA Ames Research Center

NASA Technical Reports Server (NTRS)

Reid, Max B.; Bualat, Maria G.; Cho, Young C.; Downie, John D.; Gary, Charles K.; Ma, Paul W.; Ozcan, Meric; Pryor, Anna H.; Spirkovska, Lilly

1993-01-01

The combination of analog optical processors with digital electronic systems offers the potential of tera-OPS computational performance, while often requiring less power and weight relative to all-digital systems. NASA is working to develop and demonstrate optical processing techniques for on-board, real time science and mission applications. Current research areas and applications under investigation include optical matrix processing for space structure vibration control and the analysis of Space Shuttle Main Engine plume spectra, optical correlation-based autonomous vision for robotic vehicles, analog computation for robotic path planning, free-space optical interconnections for information transfer within digital electronic computers, and multiplexed arrays of fiber optic interferometric sensors for acoustic and vibration measurements.

Grid-supported Medical Digital Library.

PubMed

Kosiedowski, Michal; Mazurek, Cezary; Stroinski, Maciej; Weglarz, Jan

2007-01-01

Secure, flexible and efficient storing and accessing digital medical data is one of the key elements for delivering successful telemedical systems. To this end grid technologies designed and developed over the recent years and grid infrastructures deployed with their use seem to provide an excellent opportunity for the creation of a powerful environment capable of delivering tools and services for medical data storage, access and processing. In this paper we present the early results of our work towards establishing a Medical Digital Library supported by grid technologies and discuss future directions of its development. These works are part of the "Telemedycyna Wielkopolska" project aiming to develop a telemedical system for the support of the regional healthcare.

Digital Electronics for Nuclear Physics Experiments

NASA Astrophysics Data System (ADS)

Skulski, Wojtek; Hunter, David; Druszkiewicz, Eryk; Khaitan, Dev Ashish; Yin, Jun; Wolfs, Frank; SkuTek Instrumentation Team; Department of Physics; Astronomy, University of Rochester Team

2015-10-01

Future detectors in nuclear physics will use signal sampling as one of primary techniques of data acquisition. Using the digitized waveforms, the electronics can select events based on pulse shape, total energy, multiplicity, and the hit pattern. The DAQ for the LZ Dark Matter detector, now under development in Rochester, is a good example of the power of digital signal processing. This system, designed around 32-channel, FPGA-based, digital signal processors collects data from more than one thousand channels. The solutions developed for this DAQ can be applied to nuclear physics experiments. Supported by the Department of Energy Office of Science under Grant DE-SC0009543.

WTEC panel report on European nuclear instrumentation and controls

NASA Technical Reports Server (NTRS)

White, James D.; Lanning, David D.; Beltracchi, Leo; Best, Fred R.; Easter, James R.; Oakes, Lester C.; Sudduth, A. L.

1991-01-01

Control and instrumentation systems might be called the 'brain' and 'senses' of a nuclear power plant. As such they become the key elements in the integrated operation of these plants. Recent developments in digital equipment have allowed a dramatic change in the design of these instrument and control (I&C) systems. New designs are evolving with cathode ray tube (CRT)-based control rooms, more automation, and better logical information for the human operators. As these new advanced systems are developed, various decisions must be made about the degree of automation and the human-to-machine interface. Different stages of the development of control automation and of advanced digital systems can be found in various countries. The purpose of this technology assessment is to make a comparative evaluation of the control and instrumentation systems that are being used for commercial nuclear power plants in Europe and the United States. This study is limited to pressurized water reactors (PWR's). Part of the evaluation includes comparisons with a previous similar study assessing Japanese technology.

Regulatory Guidance for Lightning Protection in Nuclear Power Plants

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

Kisner, Roger A; Wilgen, John B; Ewing, Paul D

2006-01-01

Abstract - Oak Ridge National Laboratory (ORNL) was engaged by the U.S. Nuclear Regulatory Commission (NRC) Office of Nuclear Regulatory Research (RES) to develop the technical basis for regulatory guidance to address design and implementation practices for lightning protection systems in nuclear power plants (NPPs). Lightning protection is becoming increasingly important with the advent of digital and low-voltage analog systems in NPPs. These systems have the potential to be more vulnerable than older analog systems to the resulting power surges and electromagnetic interference (EMI) when lightning strikes facilities or power lines. This paper discusses the technical basis for guidance tomore » licensees and applicants covered in Regulatory Guide (RG) 1.204, Guidelines for Lightning Protection of Nuclear Power Plants, issued August 2005. RG 1.204 describes guidance for practices that are acceptable to the NRC staff for protecting nuclear power structures and systems from direct lightning strikes and the resulting secondary effects.« less

Regulatory guidance for lightning protection in nuclear power plants

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

Kisner, R. A.; Wilgen, J. B.; Ewing, P. D.

2006-07-01

Oak Ridge National Laboratory (ORNL) was engaged by the U.S. Nuclear Regulatory Commission (NRC) Office of Nuclear Regulatory Research (RES) to develop the technical basis for regulatory guidance to address design and implementation practices for lightning protection systems in nuclear power plants (NPPs). Lightning protection is becoming increasingly important with the advent of digital and low-voltage analog systems in NPPs. These systems have the potential to be more vulnerable than older analog systems to the resulting power surges and electromagnetic interference (EMI) when lightning strikes facilities or power lines. This paper discusses the technical basis for guidance to licensees andmore » applicants covered in Regulatory Guide (RG) 1.204, Guidelines for Lightning Protection of Nuclear Power Plants, issued August 2005. RG 1.204 describes guidance for practices that are acceptable to the NRC staff for protecting nuclear power structures and systems from direct lightning strikes and the resulting secondary effects. (authors)« less

76 FR 72849 - Digital Low Power Television, Television Translator, and Television Booster Stations and To Amend...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-28

...] Digital Low Power Television, Television Translator, and Television Booster Stations and To Amend Rules... for Digital Low Power Television, Television Translator, and Television Booster Stations and to Amend... television, TV translator, and Class A television station DTV licensees''). The Commission has also revised...

Hardening digital systems with distributed functionality: robust networks

NASA Astrophysics Data System (ADS)

Vaskova, Anna; Portela-Garcia, Marta; Garcia-Valderas, Mario; López-Ongil, Celia; Portilla, Jorge; Valverde, Juan; de la Torre, Eduardo; Riesgo, Teresa

2013-05-01

Collaborative hardening and hardware redundancy are nowadays the most interesting solutions in terms of fault tolerance achieved and low extra cost imposed to the project budget. Thanks to the powerful and cheap digital devices that are available in the market, extra processing capabilities can be used for redundant tasks, not only in early data processing (sensed data) but also in routing and interfacing1

47 CFR 74.794 - Digital emissions.

Code of Federal Regulations, 2010 CFR

2010-10-01

..., AUXILIARY, SPECIAL BROADCAST AND OTHER PROGRAM DISTRIBUTIONAL SERVICES Low Power TV, TV Translator, and TV Booster Stations § 74.794 Digital emissions. (a)(1) An applicant for a digital LPTV or TV translator... (including attenuation of radio frequency harmonics), digital low power TV and TV translator stations...

A low power biomedical signal processor ASIC based on hardware software codesign.

PubMed

Nie, Z D; Wang, L; Chen, W G; Zhang, T; Zhang, Y T

2009-01-01

A low power biomedical digital signal processor ASIC based on hardware and software codesign methodology was presented in this paper. The codesign methodology was used to achieve higher system performance and design flexibility. The hardware implementation included a low power 32bit RISC CPU ARM7TDMI, a low power AHB-compatible bus, and a scalable digital co-processor that was optimized for low power Fast Fourier Transform (FFT) calculations. The co-processor could be scaled for 8-point, 16-point and 32-point FFTs, taking approximate 50, 100 and 150 clock circles, respectively. The complete design was intensively simulated using ARM DSM model and was emulated by ARM Versatile platform, before conducted to silicon. The multi-million-gate ASIC was fabricated using SMIC 0.18 microm mixed-signal CMOS 1P6M technology. The die area measures 5,000 microm x 2,350 microm. The power consumption was approximately 3.6 mW at 1.8 V power supply and 1 MHz clock rate. The power consumption for FFT calculations was less than 1.5 % comparing with the conventional embedded software-based solution.

Digital Signal Processing Methods for Safety Systems Employed in Nuclear Power Industry

NASA Astrophysics Data System (ADS)

Popescu, George

Some of the major safety concerns in the nuclear power industry focus on the readiness of nuclear power plant safety systems to respond to an abnormal event, the security of special nuclear materials in used nuclear fuels, and the need for physical security to protect personnel and reactor safety systems from an act of terror. Routine maintenance and tests of all nuclear reactor safety systems are performed on a regular basis to confirm the ability of these systems to operate as expected. However, these tests do not determine the reliability of these safety systems and whether the systems will perform for the duration of an accident and whether they will perform their tasks without failure after being engaged. This research has investigated the progression of spindle asynchronous error motion determined from spindle accelerations to predict bearings failure onset. This method could be applied to coolant pumps that are essential components of emergency core cooling systems at all nuclear power plants. Recent security upgrades mandated by the Nuclear Regulatory Commission and the Department of Homeland Security have resulted in implementation of multiple physical security barriers around all of the commercial and research nuclear reactors in the United States. A second part of this research attempts to address an increased concern about illegal trafficking of Special Nuclear Materials (SNM). This research describes a multi element scintillation detector system designed for non - invasive (passive) gamma ray surveillance for concealed SNM that may be within an area or sealed in a package, vehicle or shipping container. Detection capabilities of the system were greatly enhanced through digital signal processing, which allows the combination of two very powerful techniques: 1) Compton Suppression (CS) and 2) Pulse Shape Discrimination (PSD) with less reliance on complicated analog instrumentation.

A telerobotic digital controller system

NASA Technical Reports Server (NTRS)

Brown, Richard J.

1992-01-01

This system is a network of joint mounted dual axes digital servo-controllers (DDSC), providing control of various joints and end effectors of different robotic systems. This report provides description of and user required information for the Digital Controller System Network (DSCN) and, in particular, the DDSC, Model DDSC-2, developed to perform the controller functions. The DDSC can control 3 phase brushless or brush type DC motors, requiring up to 8 amps. Only four wires, two for power and 2 for serial communication, are required, except for local sensor and motor connections. This highly capable, very flexible, programmable servo-controller, contained on a single, compact printed circuit board measuring only 4.5 x 5.1 inches, is applicable to control systems of all types from sub-arc second precision pointing to control of robotic joints and end effectors. This document concentrates on the robotic applications for the DDSC.

13 CFR 121.201 - What size standards has SBA identified by North American Industry Classification System codes?

Code of Federal Regulations, 2010 CFR

2010-01-01

... footnote 1 221112 Fossil Fuel Electric Power Generation See footnote 1 221113 Nuclear Electric Power... 500 323115 Digital Printing 500 323116 Manifold Business Forms Printing 500 323117 Books Printing 500... 424590 Other Farm Product Raw Material Merchant Wholesalers 100 424610 Plastics Materials and Basic Forms...

13 CFR 121.201 - What size standards has SBA identified by North American Industry Classification System codes?

Code of Federal Regulations, 2012 CFR

2012-01-01

... footnote 1 221112 Fossil Fuel Electric Power Generation See footnote 1 221113 Nuclear Electric Power... 500 323115 Digital Printing 500 323116 Manifold Business Forms Printing 500 323117 Books Printing 500... Merchant Wholesalers 100 424610 Plastics Materials and Basic Forms and Shapes Merchant Wholesalers 100...

13 CFR 121.201 - What size standards has SBA identified by North American Industry Classification System codes?

Code of Federal Regulations, 2011 CFR

2011-01-01

... footnote 1 221112 Fossil Fuel Electric Power Generation See footnote 1 221113 Nuclear Electric Power... 500 323115 Digital Printing 500 323116 Manifold Business Forms Printing 500 323117 Books Printing 500... Merchant Wholesalers 100 424610 Plastics Materials and Basic Forms and Shapes Merchant Wholesalers 100...

Indiana 50 M Wind Resource

Science.gov Websites

Geospatial_Data_Presentation_Form: vector digital data Other_Citation_Details: The wind power resource estimates were produced by AWS TrueWind using their MesoMap system and historical weather data under contract to Wind Powering America/NREL. This map has been validated with available surface data by NREL and wind energy

Ohio 50 m Wind Resource

Science.gov Websites

Geospatial_Data_Presentation_Form: vector digital data Other_Citation_Details: The wind power resource estimates were produced by AWS TrueWind using their MesoMap system and historical weather data under contract to Wind Powering America/NREL. This map has been validated with available surface data by NREL and wind energy

michigan_50mwind

Science.gov Websites

Geospatial_Data_Presentation_Form: vector digital data Other_Citation_Details: The wind power resource estimates were produced by AWS TrueWind using their MesoMap system and historical weather data under contract to Wind Powering America/NREL. This map has been validated with available surface data by NREL and wind energy

Missouri 50 m Wind Resource

Science.gov Websites

Geospatial_Data_Presentation_Form: vector digital data Other_Citation_Details: The wind power resource estimates were produced by AWS TrueWind using their MesoMap system and historical weather data under contract to Wind Powering America/NREL. This map has been validated with available surface data by NREL and wind energy

nebraska_50mwind

Science.gov Websites

Geospatial_Data_Presentation_Form: vector digital data Other_Citation_Details: The wind power resource estimates were produced by TrueWind Solutions using their MesoMap system and historical weather data under contract to Wind Powering America/NREL. This map has been validated with available surface data by NREL and wind energy

Wearable Health Monitoring Systems

NASA Technical Reports Server (NTRS)

Bell, John

2015-01-01

The shrinking size and weight of electronic circuitry has given rise to a new generation of smart clothing that enables biological data to be measured and transmitted. As the variation in the number and type of deployable devices and sensors increases, technology must allow their seamless integration so they can be electrically powered, operated, and recharged over a digital pathway. Nyx Illuminated Clothing Company has developed a lightweight health monitoring system that integrates medical sensors, electrodes, electrical connections, circuits, and a power supply into a single wearable assembly. The system is comfortable, bendable in three dimensions, durable, waterproof, and washable. The innovation will allow astronaut health monitoring in a variety of real-time scenarios, with data stored in digital memory for later use in a medical database. Potential commercial uses are numerous, as the technology enables medical personnel to noninvasively monitor patient vital signs in a multitude of health care settings and applications.

A self-tuning automatic voltage regulator designed for an industrial environment

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

Flynn, D.; Hogg, B.W.; Swidenbank, E.

Examination of the performance of fixed parameter controllers has resulted in the development of self-tuning strategies for excitation control of turbogenerator systems. In conjunction with the advanced control algorithms, sophisticated measurement techniques have previously been adopted on micromachine systems to provide generator terminal quantities. In power stations, however, a minimalist hardware arrangement would be selected leading to relatively simple measurement techniques. The performance of a range of self-tuning schemes is investigated on an industrial test-bed, employing a typical industrial hardware measurement system. Individual controllers are implemented on a standard digital automatic voltage regulator, as installed in power stations. This employsmore » a VME platform, and the self-tuning algorithms are introduced by linking to a transputer network. The AVR includes all normal features, such as field forcing, VAR limiting and overflux protection. Self-tuning controller performance is compared with that of a fixed gain digital AVR.« less

An Implantable RFID Sensor Tag toward Continuous Glucose Monitoring.

PubMed

Xiao, Zhibin; Tan, Xi; Chen, Xianliang; Chen, Sizheng; Zhang, Zijian; Zhang, Hualei; Wang, Junyu; Huang, Yue; Zhang, Peng; Zheng, Lirong; Min, Hao

2015-05-01

This paper presents a wirelessly powered implantable electrochemical sensor tag for continuous blood glucose monitoring. The system is remotely powered by a 13.56-MHz inductive link and utilizes an ISO 15693 radio frequency identification (RFID) standard for communication. This paper provides reliable and accurate measurement for changing glucose level. The sensor tag employs a long-term glucose sensor, a winding ferrite antenna, an RFID front-end, a potentiostat, a 10-bit sigma-delta analog to digital converter, an on-chip temperature sensor, and a digital baseband for protocol processing and control. A high-frequency external reader is used to power, command, and configure the sensor tag. The only off-chip support circuitry required is a tuned antenna and a glucose microsensor. The integrated chip fabricated in SMIC 0.13-μm CMOS process occupies an area of 1.2 mm ×2 mm and consumes 50 μW. The power sensitivity of the whole system is -4 dBm. The sensor tag achieves a measured glucose range of 0-30 mM with a sensitivity of 0.75 nA/mM.

Analytical design of a parasitic-loading digital speed controller for a 400-hertz turbine driven alternator

NASA Technical Reports Server (NTRS)

Ingle, B. D.; Ryan, J. P.

1972-01-01

A design for a solid-state parasitic speed controller using digital logic was analyzed. Parasitic speed controllers are used in space power electrical generating systems to control the speed of turbine-driven alternators within specified limits. The analysis included the performance characteristics of the speed controller and the generation of timing functions. The speed controller using digital logic applies step loads to the alternator. The step loads conduct for a full half wave starting at either zero or 180 electrical degrees.

FPGA platform for MEMS Disc Resonance Gyroscope (DRG) control

NASA Astrophysics Data System (ADS)

Keymeulen, Didier; Peay, Chris; Foor, David; Trung, Tran; Bakhshi, Alireza; Withington, Phil; Yee, Karl; Terrile, Rich

2008-04-01

Inertial navigation systems based upon optical gyroscopes tend to be expensive, large, power consumptive, and are not long lived. Micro-Electromechanical Systems (MEMS) based gyros do not have these shortcomings; however, until recently, the performance of MEMS based gyros had been below navigation grade. Boeing and JPL have been cooperating since 1997 to develop high performance MEMS gyroscopes for miniature, low power space Inertial Reference Unit applications. The efforts resulted in demonstration of a Post Resonator Gyroscope (PRG). This experience led to the more compact Disc Resonator Gyroscope (DRG) for further reduced size and power with potentially increased performance. Currently, the mass, volume and power of the DRG are dominated by the size of the electronics. This paper will detail the FPGA based digital electronics architecture and its implementation for the DRG which will allow reduction of size and power and will increase performance through a reduction in electronics noise. Using the digital control based on FPGA, we can program and modify in real-time the control loop to adapt to the specificity of each particular gyro and the change of the mechanical characteristic of the gyro during its life time.

A Low-Power High-Dynamic-Range Receiver System for In-Probe 3-D Ultrasonic Imaging.

PubMed

Attarzadeh, Hourieh; Xu, Ye; Ytterdal, Trond

2017-10-01

In this paper, a dual-mode low-power, high dynamic-range receiver circuit is designed for the interface with a capacitive micromachined ultrasonic transducer. The proposed ultrasound receiver chip enables the development of an in-probe digital beamforming imaging system. The flexibility of having two operation modes offers a high dynamic range with minimum power sacrifice. A prototype of the chip containing one receive channel, with one variable transimpedance amplifier (TIA) and one analog to digital converter (ADC) circuit is implemented. Combining variable gain TIA functionality with ADC gain settings achieves an enhanced overall high dynamic range, while low power dissipation is maintained. The chip is designed and fabricated in a 65 nm standard CMOS process technology. The test chip occupies an area of 76[Formula: see text] 170 [Formula: see text]. A total average power range of 60-240 [Formula: see text] for a sampling frequency of 30 MHz, and a center frequency of 5 MHz is measured. An instantaneous dynamic range of 50.5 dB with an overall dynamic range of 72 dB is obtained from the receiver circuit.

Analysis and Design of Ultra Wide-Band and High-Power Microwave Pulse Interactions With Electronic Circuits and Systems

DTIC Science & Technology

2007-02-28

upset, latch -up or failure of systems of digital components. A digital system can be in many different states, depending on its internal functioning...the Interface between Isorefractive Half-spaces A Y,A0 + B I (c). Cavity-Backed Gap in a Corner (d). A Right-Angle Isorefractive Wedge Structure z LL...ikjI I E2,:, (e) . A +-l l(ii (c). e Ca ity-Backedfraptive MatCoeria (d. BeRgt-Angl Isorefractive Wedge -Structur B V-T A.. D .F V-0 G x V-:x C E Y’-2

Transient analysis of an HTS DC power cable with an HVDC system

NASA Astrophysics Data System (ADS)

Dinh, Minh-Chau; Ju, Chang-Hyeon; Kim, Jin-Geun; Park, Minwon; Yu, In-Keun; Yang, Byeongmo

2013-11-01

The operational characteristics of a superconducting DC power cable connected to a highvoltage direct current (HVDC) system are mainly concerned with the HVDC control and protection system. To confirm how the cable operates with the HVDC system, verifications using simulation tools are needed. This paper presents a transient analysis of a high temperature superconducting (HTS) DC power cable in connection with an HVDC system. The study was conducted via the simulation of the HVDC system and a developed model of the HTS DC power cable using a real time digital simulator (RTDS). The simulation was performed with some cases of short circuits that may have caused system damage. The simulation results show that during the faults, the quench did not happen with the HTS DC power cable because the HVDC controller reduced some degree of the fault current. These results could provide useful data for the protection design of a practical HVDC and HTS DC power cable system.

Field-Deployable Acoustic Digital Systems for Noise Measurement

NASA Technical Reports Server (NTRS)

Shams, Qamar A.; Wright, Kenneth D.; Lunsford, Charles B.; Smith, Charlie D.

2000-01-01

Langley Research Center (LaRC) has for years been a leader in field acoustic array measurement technique. Two field-deployable digital measurement systems have been developed to support acoustic research programs at LaRC. For several years, LaRC has used the Digital Acoustic Measurement System (DAMS) for measuring the acoustic noise levels from rotorcraft and tiltrotor aircraft. Recently, a second system called Remote Acquisition and Storage System (RASS) was developed and deployed for the first time in the field along with DAMS system for the Community Noise Flight Test using the NASA LaRC-757 aircraft during April, 2000. The test was performed at Airborne Airport in Wilmington, OH to validate predicted noise reduction benefits from alternative operational procedures. The test matrix was composed of various combinations of altitude, cutback power, and aircraft weight. The DAMS digitizes the acoustic inputs at the microphone site and can be located up to 2000 feet from the van which houses the acquisition, storage and analysis equipment. Digitized data from up to 10 microphones is recorded on a Jaz disk and is analyzed post-test by microcomputer system. The RASS digitizes and stores acoustic inputs at the microphone site that can be located up to three miles from the base station and can compose a 3 mile by 3 mile array of microphones. 16-bit digitized data from the microphones is stored on removable Jaz disk and is transferred through a high speed array to a very large high speed permanent storage device. Up to 30 microphones can be utilized in the array. System control and monitoring is accomplished via Radio Frequency (RF) link. This paper will present a detailed description of both systems, along with acoustic data analysis from both systems.

Flight control systems development of highly maneuverable aircraft technology /HiMAT/ vehicle

NASA Technical Reports Server (NTRS)

Petersen, K. L.

1979-01-01

The highly maneuverable aircraft technology (HiMAT) program was conceived to demonstrate advanced technology concepts through scaled-aircraft flight tests using a remotely piloted technique. Closed-loop primary flight control is performed from a ground-based cockpit, utilizing a digital computer and up/down telemetry links. A backup flight control system for emergency operation resides in an onboard computer. The onboard systems are designed to provide fail-operational capabilities and utilize two microcomputers, dual uplink receiver/decoders, and redundant hydraulic actuation and power systems. This paper discusses the design and validation of the primary and backup digital flight control systems as well as the unique pilot and specialized systems interfaces.

Motor run-up system. [power lines

NASA Technical Reports Server (NTRS)

Daeges, J. J. (Inventor)

1975-01-01

A starting system is described for bringing a large synchronous motor up to speed to prevent large power line disturbances at the moment the motor is connected to the power line. The system includes (1) a digital counter which generates a count determined by the difference in frequency between the power line and a small current generated by the synchronous motor; (2) a latch which stores the count; and (3) a comparator which compares the stored count with a newly generated count to determine whether the synchronous motor is accelerating or decelerating. Signals generated by the counter and comparator control the current to a clutch that couples a starting motor to the large synchronous motor.

SPROC: A multiple-processor DSP IC

NASA Technical Reports Server (NTRS)

Davis, R.

1991-01-01

A large, single-chip, multiple-processor, digital signal processing (DSP) integrated circuit (IC) fabricated in HP-Cmos34 is presented. The innovative architecture is best suited for analog and real-time systems characterized by both parallel signal data flows and concurrent logic processing. The IC is supported by a powerful development system that transforms graphical signal flow graphs into production-ready systems in minutes. Automatic compiler partitioning of tasks among four on-chip processors gives the IC the signal processing power of several conventional DSP chips.

Hybrid digital-analog coding with bandwidth expansion for correlated Gaussian sources under Rayleigh fading

NASA Astrophysics Data System (ADS)

Yahampath, Pradeepa

2017-12-01

Consider communicating a correlated Gaussian source over a Rayleigh fading channel with no knowledge of the channel signal-to-noise ratio (CSNR) at the transmitter. In this case, a digital system cannot be optimal for a range of CSNRs. Analog transmission however is optimal at all CSNRs, if the source and channel are memoryless and bandwidth matched. This paper presents new hybrid digital-analog (HDA) systems for sources with memory and channels with bandwidth expansion, which outperform both digital-only and analog-only systems over a wide range of CSNRs. The digital part is either a predictive quantizer or a transform code, used to achieve a coding gain. Analog part uses linear encoding to transmit the quantization error which improves the performance under CSNR variations. The hybrid encoder is optimized to achieve the minimum AMMSE (average minimum mean square error) over the CSNR distribution. To this end, analytical expressions are derived for the AMMSE of asymptotically optimal systems. It is shown that the outage CSNR of the channel code and the analog-digital power allocation must be jointly optimized to achieve the minimum AMMSE. In the case of HDA predictive quantization, a simple algorithm is presented to solve the optimization problem. Experimental results are presented for both Gauss-Markov sources and speech signals.

Control Board Digital Interface Input Devices – Touchscreen, Trackpad, or Mouse?

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

Thomas A. Ulrich; Ronald L. Boring; Roger Lew

The authors collaborated with a power utility to evaluate input devices for use in the human system interface (HSI) for a new digital Turbine Control System (TCS) at a nuclear power plant (NPP) undergoing a TCS upgrade. A standalone dynamic software simulation of the new digital TCS and a mobile kiosk were developed to conduct an input device study to evaluate operator preference and input device effectiveness. The TCS software presented the anticipated HSI for the TCS and mimicked (i.e., simulated) the turbine systems’ responses to operator commands. Twenty-four licensed operators from the two nuclear power units participated in themore » study. Three input devices were tested: a trackpad, mouse, and touchscreen. The subjective feedback from the survey indicates the operators preferred the touchscreen interface. The operators subjectively rated the touchscreen as the fastest and most comfortable input device given the range of tasks they performed during the study, but also noted a lack of accuracy for selecting small targets. The empirical data suggest the mouse input device provides the most consistent performance for screen navigation and manipulating on screen controls. The trackpad input device was both empirically and subjectively found to be the least effective and least desired input device.« less

Synthesis of a fully-integrated digital signal source for communications from chaotic dynamics-based oscillations

NASA Astrophysics Data System (ADS)

Glenn, Chance Michael, Sr.

This work is the conceptualization, derivation, analysis, and fabrication of a fully practical digital signal source designed from a chaotic oscillator. In it we show how a simple electronic circuit based upon the Colpitts oscillator, can be made to produce highly complex signals capable of carrying digital information. We show a direct relationship between the continuous-time chaotic oscillations produced by the circuit and the logistic map, which is discrete-time, one-dimensional map that is a fundamental paradigm for the study of chaotic systems. We demonstrate the direct encoding of binary information into the oscillations of the chaotic circuit. We demonstrate a new concept in power amplification, called syncrodyne amplification , which uses fundamental properties of chaotic oscillators to provide high-efficiency, high gain amplification of standard communication waveforms as well as typical chaotic oscillations. We show modeling results of this system providing nearly 60-dB power gain and 80% PAE for communications waveforms conforming to GMSK modulation. Finally we show results from a fabricated syncrodyne amplifier circuit operating at 2 MHz, providing over 40-dB power gain and 72% PAE, and propose design criteria for an 824--850 MHz circuit utilizing heterojunction bipolar transistors (HBTs), providing the basis for microwave frequency realization.

Integrated digital printing of flexible circuits for wireless sensing (Conference Presentation)

NASA Astrophysics Data System (ADS)

Mei, Ping; Whiting, Gregory L.; Schwartz, David E.; Ng, Tse Nga; Krusor, Brent S.; Ready, Steve E.; Daniel, George; Veres, Janos; Street, Bob

2016-09-01

Wireless sensing has broad applications in a wide variety of fields such as infrastructure monitoring, chemistry, environmental engineering and cold supply chain management. Further development of sensing systems will focus on achieving light weight, flexibility, low power consumption and low cost. Fully printed electronics provide excellent flexibility and customizability, as well as the potential for low cost and large area applications, but lack solutions for high-density, high-performance circuitry. Conventional electronics mounted on flexible printed circuit boards provide high performance but are not digitally fabricated or readily customizable. Incorporation of small silicon dies or packaged chips into a printed platform enables high performance without compromising flexibility or cost. At PARC, we combine high functionality c-Si CMOS and digitally printed components and interconnects to create an integrated platform that can read and process multiple discrete sensors. Our approach facilitates customization to a wide variety of sensors and user interfaces suitable for a broad range of applications including remote monitoring of health, structures and environment. This talk will describe several examples of printed wireless sensing systems. The technologies required for these sensor systems are a mix of novel sensors, printing processes, conventional microchips, flexible substrates and energy harvesting power solutions.

Reliability modeling of fault-tolerant computer based systems

NASA Technical Reports Server (NTRS)

Bavuso, Salvatore J.

1987-01-01

Digital fault-tolerant computer-based systems have become commonplace in military and commercial avionics. These systems hold the promise of increased availability, reliability, and maintainability over conventional analog-based systems through the application of replicated digital computers arranged in fault-tolerant configurations. Three tightly coupled factors of paramount importance, ultimately determining the viability of these systems, are reliability, safety, and profitability. Reliability, the major driver affects virtually every aspect of design, packaging, and field operations, and eventually produces profit for commercial applications or increased national security. However, the utilization of digital computer systems makes the task of producing credible reliability assessment a formidable one for the reliability engineer. The root of the problem lies in the digital computer's unique adaptability to changing requirements, computational power, and ability to test itself efficiently. Addressed here are the nuances of modeling the reliability of systems with large state sizes, in the Markov sense, which result from systems based on replicated redundant hardware and to discuss the modeling of factors which can reduce reliability without concomitant depletion of hardware. Advanced fault-handling models are described and methods of acquiring and measuring parameters for these models are delineated.

The power of PowerPoint.

PubMed

Niamtu , J

2001-08-01

Carousel slide presentations have been used for academic and clinical presentations since the late 1950s. However, advances in computer technology have caused a paradigm shift, and digital presentations are quickly becoming standard for clinical presentations. The advantages of digital presentations include cost savings; portability; easy updating capability; Internet access; multimedia functions, such as animation, pictures, video, and sound; and customization to augment audience interest and attention. Microsoft PowerPoint has emerged as the most popular digital presentation software and is currently used by many practitioners with and without significant computer expertise. The user-friendly platform of PowerPoint enables even the novice presenter to incorporate digital presentations into his or her profession. PowerPoint offers many advanced options that, with a minimal investment of time, can be used to create more interactive and professional presentations for lectures, patient education, and marketing. Examples of advanced PowerPoint applications are presented in a stepwise manner to unveil the full power of PowerPoint. By incorporating these techniques, medical practitioners can easily personalize, customize, and enhance their PowerPoint presentations. Complications, pitfalls, and caveats are discussed to detour and prevent misadventures in digital presentations. Relevant Web sites are listed to further update, customize, and communicate PowerPoint techniques.

FERMI: a digital Front End and Readout MIcrosystem for high resolution calorimetry

NASA Astrophysics Data System (ADS)

Alexanian, H.; Appelquist, G.; Bailly, P.; Benetta, R.; Berglund, S.; Bezamat, J.; Blouzon, F.; Bohm, C.; Breveglieri, L.; Brigati, S.; Cattaneo, P. W.; Dadda, L.; David, J.; Engström, M.; Genat, J. F.; Givoletti, M.; Goggi, V. G.; Gong, S.; Grieco, G. M.; Hansen, M.; Hentzell, H.; Holmberg, T.; Höglund, I.; Inkinen, S. J.; Kerek, A.; Landi, C.; Ledortz, O.; Lippi, M.; Lofstedt, B.; Lund-Jensen, B.; Maloberti, F.; Mutz, S.; Nayman, P.; Piuri, V.; Polesello, G.; Sami, M.; Savoy-Navarro, A.; Schwemling, P.; Stefanelli, R.; Sundblad, R.; Svensson, C.; Torelli, G.; Vanuxem, J. P.; Yamdagni, N.; Yuan, J.; Ödmark, A.; Fermi Collaboration

1995-02-01

We present a digital solution for the front-end electronics of high resolution calorimeters at future colliders. It is based on analogue signal compression, high speed {A}/{D} converters, a fully programmable pipeline and a digital signal processing (DSP) chain with local intelligence and system supervision. This digital solution is aimed at providing maximal front-end processing power by performing waveform analysis using DSP methods. For the system integration of the multichannel device a multi-chip, silicon-on-silicon multi-chip module (MCM) has been adopted. This solution allows a high level of integration of complex analogue and digital functions, with excellent flexibility in mixing technologies for the different functional blocks. This type of multichip integration provides a high degree of reliability and programmability at both the function and the system level, with the additional possibility of customising the microsystem to detector-specific requirements. For enhanced reliability in high radiation environments, fault tolerance strategies, i.e. redundancy, reconfigurability, majority voting and coding for error detection and correction, are integrated into the design.

Design of Efficient Mirror Adder in Quantum- Dot Cellular Automata

NASA Astrophysics Data System (ADS)

Mishra, Prashant Kumar; Chattopadhyay, Manju K.

2018-03-01

Lower power consumption is an essential demand for portable multimedia system using digital signal processing algorithms and architectures. Quantum dot cellular automata (QCA) is a rising nano technology for the development of high performance ultra-dense low power digital circuits. QCA based several efficient binary and decimal arithmetic circuits are implemented, however important improvements are still possible. This paper demonstrate Mirror Adder circuit design in QCA. We present comparative study of mirror adder cells designed using conventional CMOS technique and mirror adder cells designed using quantum-dot cellular automata. QCA based mirror adders are better in terms of area by order of three.

A wideband, high-resolution spectrum analyzer

NASA Technical Reports Server (NTRS)

Quirk, M. P.; Wilck, H. C.; Garyantes, M. F.; Grimm, M. J.

1988-01-01

A two-million-channel, 40 MHz bandwidth, digital spectrum analyzer under development at the Jet Propulsion Laboratory is described. The analyzer system will serve as a prototype processor for the sky survey portion of NASA's Search for Extraterrestrial Intelligence program and for other applications in the Deep Space Network. The analyzer digitizes an analog input, performs a 2 (sup 21) point Discrete Fourier Transform, accumulates the output power, normalizes the output to remove frequency-dependent gain, and automates simple signal detection algorithms. Due to its built-in frequency-domain processing functions and configuration flexibility, the analyzer is a very powerful tool for real-time signal analysis.

A wide-band high-resolution spectrum analyzer

NASA Technical Reports Server (NTRS)

Quirk, Maureen P.; Garyantes, Michael F.; Wilck, Helmut C.; Grimm, Michael J.

1988-01-01

A two-million-channel, 40 MHz bandwidth, digital spectrum analyzer under development at the Jet Propulsion Laboratory is described. The analyzer system will serve as a prototype processor for the sky survey portion of NASA's Search for Extraterrestrial Intelligence program and for other applications in the Deep Space Network. The analyzer digitizes an analog input, performs a 2 (sup 21) point Discrete Fourier Transform, accumulates the output power, normalizes the output to remove frequency-dependent gain, and automates simple detection algorithms. Due to its built-in frequency-domain processing functions and configuration flexibility, the analyzer is a very powerful tool for real-time signal analysis.

A wide-band high-resolution spectrum analyzer.

PubMed

Quirk, M P; Garyantes, M F; Wilck, H C; Grimm, M J

1988-12-01

This paper describes a two-million-channel 40-MHz-bandwidth, digital spectrum analyzer under development at the Jet Propulsion Laboratory. The analyzer system will serve as a prototype processor for the sky survey portion of NASA's Search for Extraterrestrial Intelligence program and for other applications in the Deep Space Network. The analyzer digitizes an analog input, performs a 2(21)-point, Discrete Fourier Transform, accumulates the output power, normalizes the output to remove frequency-dependent gain, and automates simple signal detection algorithms. Due to its built-in frequency-domain processing functions and configuration flexibility, the analyzer is a very powerful tool for real-time signal analysis and detection.

47 CFR 74.786 - Digital channel assignments.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Translator, and TV Booster Stations § 74.786 Digital channel assignments. (a) An applicant for a new low power television or television translator digital station or for changes in the facilities of an... VHF digital low power television or television translator station. Channels 5 and 6 assigned in Alaska...

622-Mbps Orthogonal Frequency Division Multiplexing (OFDM) Digital Modem Implemented

NASA Technical Reports Server (NTRS)

Kifle, Muli; Bizon, Thomas P.; Nguyen, Nam T.; Tran, Quang K.; Mortensen, Dale J.

2002-01-01

Future generation space communications systems feature significantly higher data rates and relatively smaller frequency spectrum allocations than systems currently deployed. This requires the application of bandwidth- and power-efficient signal transmission techniques. There are a number of approaches to implementing such techniques, including analog, digital, mixed-signal, single-channel, or multichannel systems. In general, the digital implementations offer more advantages; however, a fully digital implementation is very difficult because of the very high clock speeds required. Multichannel techniques are used to reduce the sampling rate. One such technique, multicarrier modulation, divides the data into a number of low-rate channels that are stacked in frequency. Orthogonal frequency division multiplexing (OFDM), a form of multicarrier modulation, is being proposed for numerous systems, including mobile wireless and digital subscriber link communication systems. In response to this challenge, NASA Glenn Research Center's Communication Technology Division has developed an OFDM digital modem (modulator and demodulator) with an aggregate information throughput of 622 Mbps. The basic OFDM waveform is constructed by dividing an incoming data stream into four channels, each using either 16- ary quadrature amplitude modulation (16-QAM) or 8-phase shift keying (8-PSK). An efficient implementation for an OFDM architecture is being achieved using the combination of a discrete Fourier transform (DFT) at the transmitter to digitally stack the individual carriers, inverse DFT at the receiver to perform the frequency translations, and a polyphase filter to facilitate the pulse shaping.

High-power VCSEL systems and applications

NASA Astrophysics Data System (ADS)

Moench, Holger; Conrads, Ralf; Deppe, Carsten; Derra, Guenther; Gronenborn, Stephan; Gu, Xi; Heusler, Gero; Kolb, Johanna; Miller, Michael; Pekarski, Pavel; Pollmann-Retsch, Jens; Pruijmboom, Armand; Weichmann, Ulrich

2015-03-01

Easy system design, compactness and a uniform power distribution define the basic advantages of high power VCSEL systems. Full addressability in space and time add new dimensions for optimization and enable "digital photonic production". Many thermal processes benefit from the improved control i.e. heat is applied exactly where and when it is needed. The compact VCSEL systems can be integrated into most manufacturing equipment, replacing batch processes using large furnaces and reducing energy consumption. This paper will present how recent technological development of high power VCSEL systems will extend efficiency and flexibility of thermal processes and replace not only laser systems, lamps and furnaces but enable new ways of production. High power VCSEL systems are made from many VCSEL chips, each comprising thousands of low power VCSELs. Systems scalable in power from watts to multiple ten kilowatts and with various form factors utilize a common modular building block concept. Designs for reliable high power VCSEL arrays and systems can be developed and tested on each building block level and benefit from the low power density and excellent reliability of the VCSELs. Furthermore advanced assembly concepts aim to reduce the number of individual processes and components and make the whole system even more simple and reliable.

Taking the Observatory to the Astronomer

NASA Astrophysics Data System (ADS)

Bisque, T. M.

1997-05-01

Since 1992, Software Bisque's Remote Astronomy Software has been used by the Mt. Wilson Institute to allow interactive control of a 24" telescope and digital camera via modem. Software Bisque now introduces a comparable, relatively low-cost observatory system that allows powerful, yet "user-friendly" telescope and CCD camera control via the Internet. Utilizing software developed for the Windows 95/NT operating systems, the system offers point-and-click access to comprehensive celestial databases, extremely accurate telescope pointing, rapid download of digital CCD images by one or many users and flexible image processing software for data reduction and analysis. Our presentation will describe how the power of the personal computer has been leveraged to provide professional-level tools to the amateur astronomer, and include a description of this system's software and hardware components. The system software includes TheSky Astronomy Software?, CCDSoft CCD Astronomy Software?, TPoint Telescope Pointing Analysis System? software, Orchestrate? and, optionally, the RealSky CDs. The system hardware includes the Paramount GT-1100? Robotic Telescope Mount, as well as third party CCD cameras, focusers and optical tube assemblies.

Optimization and Comparison of Different Digital Mammographic Tomosynthesis Reconstruction Methods

DTIC Science & Technology

2007-04-01

physical measurements of impulse response analysis, modulation transfer function (MTF) and noise power spectrum (NPS). (Months 5- 12). 1.2.1. Simulate...added: projection images with simulated impulse and the 1/r2 shading difference. Other system blur and noise issues were not addressed in this paper...spectrum (NPS), Noise -equivalent quanta (NEQ), impulse response, Back Projection (BP) 1. INTRODUCTION Digital breast tomosynthesis is a new

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

McKinnon, Archibald D.; Thompson, Seth R.; Doroshchuk, Ruslan A.

mart grid technologies are transforming the electric power grid into a grid with bi-directional flows of both power and information. Operating millions of new smart meters and smart appliances will significantly impact electric distribution systems resulting in greater efficiency. However, the scale of the grid and the new types of information transmitted will potentially introduce several security risks that cannot be addressed by traditional, centralized security techniques. We propose a new bio-inspired cyber security approach. Social insects, such as ants and bees, have developed complex-adaptive systems that emerge from the collective application of simple, light-weight behaviors. The Digital Ants frameworkmore » is a bio-inspired framework that uses mobile light-weight agents. Sensors within the framework use digital pheromones to communicate with each other and to alert each other of possible cyber security issues. All communication and coordination is both localized and decentralized thereby allowing the framework to scale across the large numbers of devices that will exist in the smart grid. Furthermore, the sensors are light-weight and therefore suitable for implementation on devices with limited computational resources. This paper will provide a brief overview of the Digital Ants framework and then present results from test bed-based demonstrations that show that Digital Ants can identify a cyber attack scenario against smart meter deployments.« less

Hybrid digital-analog video transmission in wireless multicast and multiple-input multiple-output system

NASA Astrophysics Data System (ADS)

Liu, Yu; Lin, Xiaocheng; Fan, Nianfei; Zhang, Lin

2016-01-01

Wireless video multicast has become one of the key technologies in wireless applications. But the main challenge of conventional wireless video multicast, i.e., the cliff effect, remains unsolved. To overcome the cliff effect, a hybrid digital-analog (HDA) video transmission framework based on SoftCast, which transmits the digital bitstream with the quantization residuals, is proposed. With an effective power allocation algorithm and appropriate parameter settings, the residual gains can be maximized; meanwhile, the digital bitstream can assure transmission of a basic video to the multicast receiver group. In the multiple-input multiple-output (MIMO) system, since nonuniform noise interference on different antennas can be regarded as the cliff effect problem, ParCast, which is a variation of SoftCast, is also applied to video transmission to solve it. The HDA scheme with corresponding power allocation algorithms is also applied to improve video performance. Simulations show that the proposed HDA scheme can overcome the cliff effect completely with the transmission of residuals. What is more, it outperforms the compared WSVC scheme by more than 2 dB when transmitting under the same bandwidth, and it can further improve performance by nearly 8 dB in MIMO when compared with the ParCast scheme.

A digital prediction algorithm for a single-phase boost PFC

NASA Astrophysics Data System (ADS)

Qing, Wang; Ning, Chen; Weifeng, Sun; Shengli, Lu; Longxing, Shi

2012-12-01

A novel digital control algorithm for digital control power factor correction is presented, which is called the prediction algorithm and has a feature of a higher PF (power factor) with lower total harmonic distortion, and a faster dynamic response with the change of the input voltage or load current. For a certain system, based on the current system state parameters, the prediction algorithm can estimate the track of the output voltage and the inductor current at the next switching cycle and get a set of optimized control sequences to perfectly track the trajectory of input voltage. The proposed prediction algorithm is verified at different conditions, and computer simulation and experimental results under multi-situations confirm the effectiveness of the prediction algorithm. Under the circumstances that the input voltage is in the range of 90-265 V and the load current in the range of 20%-100%, the PF value is larger than 0.998. The startup and the recovery times respectively are about 0.1 s and 0.02 s without overshoot. The experimental results also verify the validity of the proposed method.

Near-toll quality digital speech transmission in the mobile satellite service

NASA Technical Reports Server (NTRS)

Townes, S. A.; Divsalar, D.

1986-01-01

This paper discusses system considerations for near-toll quality digital speech transmission in a 5 kHz mobile satellite system channel. Tradeoffs are shown for power performance versus delay for a 4800 bps speech compression system in conjunction with a 16 state rate 2/3 trellis coded 8PSK modulation system. The suggested system has an additional 150 ms of delay beyond the propagation delay and requires an E(b)/N(0) of about 7 dB for a Ricean channel assumption with line-of-sight to diffuse component ratio of 10 assuming ideal synchronization. An additional loss of 2 to 3 dB is expected for synchronization in fading environment.

One GHz digitizer for space based laser altimeter

NASA Technical Reports Server (NTRS)

Staples, Edward J.

1991-01-01

This is the final report for the research and development of the one GHz digitizer for space based laser altimeter. A feasibility model was designed, built, and tested. Only partial testing of essential functions of the digitizer was completed. Hybrid technology was incorporated which allows analog storage (memory) of the digitally sampled data. The actual sampling rate is 62.5 MHz, but executed in 16 parallel channels, to provide an effective sampling rate of one GHz. The average power consumption of the one GHz digitizer is not more than 1.5 Watts. A one GHz oscillator is incorporated for timing purposes. This signal is also made available externally for system timing. A software package was also developed for internal use (controls, commands, etc.) and for data communication with the host computer. The digitizer is equipped with an onboard microprocessor for this purpose.

21 CFR 1311.45 - Requirements for registrants that allow powers of attorney to obtain CSOS digital certificates...

Code of Federal Regulations, 2011 CFR

2011-04-01

... attorney to obtain CSOS digital certificates under their DEA registration. 1311.45 Section 1311.45 Food and... registrants that allow powers of attorney to obtain CSOS digital certificates under their DEA registration. (a) A registrant that grants power of attorney must report to the DEA Certification Authority within 6...

Inertial Response of Wind Power Plants: A Comparison of Frequency-Based Inertial Control and Stepwise Inertial Control

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

Wang, Xiao; Gao, Wenzhong; Wang, Jianhui

The frequency regulation capability of a wind power plant plays an important role in enhancing frequency reliability especially in an isolated power system with high wind power penetration levels. A comparison of two types of inertial control methods, namely frequency-based inertial control (FBIC) and stepwise inertial control (SIC), is presented in this paper. Comprehensive case studies are carried out to reveal features of the different inertial control methods, simulated in a modified Western System Coordination Council (WSCC) nine-bus power grid using real-time digital simulator (RTDS) platform. The simulation results provide an insight into the inertial control methods under various scenarios.

47 CFR 74.791 - Digital call signs.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Booster Stations § 74.791 Digital call signs. (a) Digital low power stations. Call signs for digital low power stations will be made up of a prefix consisting of the initial letter K or W followed by the channel number assigned to the station and two additional letters and a suffix consisting of the letters...

47 CFR 74.791 - Digital call signs.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Booster Stations § 74.791 Digital call signs. (a) Digital low power stations. Call signs for digital low power stations will be made up of a prefix consisting of the initial letter K or W followed by the channel number assigned to the station and two additional letters and a suffix consisting of the letters...

47 CFR 74.791 - Digital call signs.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Booster Stations § 74.791 Digital call signs. (a) Digital low power stations. Call signs for digital low power stations will be made up of a prefix consisting of the initial letter K or W followed by the channel number assigned to the station and two additional letters and a suffix consisting of the letters...

47 CFR 74.791 - Digital call signs.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Booster Stations § 74.791 Digital call signs. (a) Digital low power stations. Call signs for digital low power stations will be made up of a prefix consisting of the initial letter K or W followed by the channel number assigned to the station and two additional letters and a suffix consisting of the letters...

Development of a digital method for neutron/gamma-ray discrimination based on matched filtering

NASA Astrophysics Data System (ADS)

Korolczuk, S.; Linczuk, M.; Romaniuk, R.; Zychor, I.

2016-09-01

Neutron/gamma-ray discrimination is crucial for measurements with detectors sensitive to both neutron and gamma-ray radiation. Different techniques to discriminate between neutrons and gamma-rays based on pulse shape analysis are widely used in many applications, e.g., homeland security, radiation dosimetry, environmental monitoring, fusion experiments, nuclear spectroscopy. A common requirement is to improve a radiation detection level with a high detection reliability. Modern electronic components, such as high speed analog to digital converters and powerful programmable digital circuits for signal processing, allow us to develop a fully digital measurement system. With this solution it is possible to optimize digital signal processing algorithms without changing any electronic components in an acquisition signal path. We report on results obtained with a digital acquisition system DNG@NCBJ designed at the National Centre for Nuclear Research. A 2'' × 2'' EJ309 liquid scintillator was used to register mixed neutron and gamma-ray radiation from PuBe sources. A dedicated algorithm for pulse shape discrimination, based on real-time filtering, was developed and implemented in hardware.

Distributed control system for parallel-connected DC boost converters

DOEpatents

Goldsmith, Steven

2017-08-15

The disclosed invention is a distributed control system for operating a DC bus fed by disparate DC power sources that service a known or unknown load. The voltage sources vary in v-i characteristics and have time-varying, maximum supply capacities. Each source is connected to the bus via a boost converter, which may have different dynamic characteristics and power transfer capacities, but are controlled through PWM. The invention tracks the time-varying power sources and apportions their power contribution while maintaining the DC bus voltage within the specifications. A central digital controller solves the steady-state system for the optimal duty cycle settings that achieve a desired power supply apportionment scheme for a known or predictable DC load. A distributed networked control system is derived from the central system that utilizes communications among controllers to compute a shared estimate of the unknown time-varying load through shared bus current measurements and bus voltage measurements.

High performance digital read out integrated circuit (DROIC) for infrared imaging

NASA Astrophysics Data System (ADS)

Mizuno, Genki; Olah, Robert; Oduor, Patrick; Dutta, Achyut K.; Dhar, Nibir K.

2016-05-01

Banpil Photonics has developed a high-performance Digital Read-Out Integrated Circuit (DROIC) for image sensors and camera systems targeting various military, industrial and commercial Infrared (IR) imaging applications. The on-chip digitization of the pixel output eliminates the necessity for an external analog-to-digital converter (ADC), which not only cuts costs, but also enables miniaturization of packaging to achieve SWaP-C camera systems. In addition, the DROIC offers new opportunities for greater on-chip processing intelligence that are not possible in conventional analog ROICs prevalent today. Conventional ROICs, which typically can enhance only one high performance attribute such as frame rate, power consumption or noise level, fail when simultaneously targeting the most aggressive performance requirements demanded in imaging applications today. Additionally, scaling analog readout circuits to meet such requirements leads to expensive, high-power consumption with large and complex systems that are untenable in the trend towards SWaP-C. We present the implementation of a VGA format (640x512 pixels 15μm pitch) capacitivetransimpedance amplifier (CTIA) DROIC architecture that incorporates a 12-bit ADC at the pixel level. The CTIA pixel input circuitry has two gain modes with programmable full-well capacity values of 100K e- and 500K e-. The DROIC has been developed with a system-on-chip architecture in mind, where all the timing and biasing are generated internally without requiring any critical external inputs. The chip is configurable with many parameters programmable through a serial programmable interface (SPI). It features a global shutter, low power, and high frame rates programmable from 30 up 500 frames per second in full VGA format supported through 24 LVDS outputs. This DROIC, suitable for hybridization with focal plane arrays (FPA) is ideal for high-performance uncooled camera applications ranging from near IR (NIR) and shortwave IR (SWIR) to mid-wave IR (MWIR) and long-wave IR (LWIR) spectral bands.

Preliminary study, analysis and design for a power switch for digital engine actuators

NASA Technical Reports Server (NTRS)

Beattie, E. C.; Zickwolf, H. C., Jr.

1979-01-01

Innovative control configurations using high temperature switches to operate actuator driving solenoids were studied. The impact on engine control system life cycle costs and reliability of electronic control and (ECU) heat dissipation due to power conditioning and interface drivers were addressed. Various power supply and actuation schemes were investigated, including optical signal transmission and electronics on the actuator, engine driven alternator, and inside the ECU. The use of a switching shunt power conditioner results in the most significant decrease in heat dissipation within the ECU. No overall control system reliability improvement is projected by the use of remote high temperature switches for solenoid drivers.

A low-power bidirectional telemetry device with a near-field charging feature for a cardiac microstimulator.

PubMed

Shuenn-Yuh Lee; Chih-Jen Cheng; Ming-Chun Liang

2011-08-01

In this paper, wireless telemetry using the near-field coupling technique with round-wire coils for an implanted cardiac microstimulator is presented. The proposed system possesses an external powering amplifier and an internal bidirectional microstimulator. The energy of the microstimulator is provided by a rectifier that can efficiently charge a rechargeable device. A fully integrated regulator and a charge pump circuit are included to generate a stable, low-voltage, and high-potential supply voltage, respectively. A miniature digital processor includes a phase-shift-keying (PSK) demodulator to decode the transmission data and a self-protective system controller to operate the entire system. To acquire the cardiac signal, a low-voltage and low-power monitoring analog front end (MAFE) performs immediate threshold detection and data conversion. In addition, the pacing circuit, which consists of a pulse generator (PG) and its digital-to-analog (D/A) controller, is responsible for stimulating heart tissue. The chip was fabricated by Taiwan Semiconductor Manufacturing Company (TSMC) with 0.35-μm complementary metal-oxide semiconductor technology to perform the monitoring and pacing functions with inductively powered communication. Using a model with lead and heart tissue on measurement, a -5-V pulse at a stimulating frequency of 60 beats per minute (bpm) is delivered while only consuming 31.5 μW of power.

The thinking of Cloud computing in the digital construction of the oil companies

NASA Astrophysics Data System (ADS)

CaoLei, Qizhilin; Dengsheng, Lei

In order to speed up digital construction of the oil companies and enhance productivity and decision-support capabilities while avoiding the disadvantages from the waste of the original process of building digital and duplication of development and input. This paper presents a cloud-based models for the build in the digital construction of the oil companies that National oil companies though the private network will join the cloud data of the oil companies and service center equipment integrated into a whole cloud system, then according to the needs of various departments to prepare their own virtual service center, which can provide a strong service industry and computing power for the Oil companies.

Phase-I investigation of high-efficiency power amplifiers for 325 and 650 MHz

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

Raab, Frederick

2018-01-27

This Phase-I SBIR grant investigated techniques for high-efficiency power amplification for DoE particle accelerators such as Project X that operate at 325 and 650 MHz. The recommended system achieves high efficiency, high reliability, and hot-swap capability by integrating class-F power amplifiers, class-S modulators, power combiners, and a digital signal processor. Experimental evaluations demonstrate the production of 120 W per transistor with overall efficiencies from 86 percent at 325 MHz and 80 percent at 650 MHz.

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

Nekoogar, Faranak; Reynolds, Matthew; Lefton, Scott

A secure optionally passive RFID tag or sensor system comprises a passive RFID tag having means for receiving radio signals from at least one base station and for transmitting radio signals to at least one base station, where the tag is capable of being powered exclusively by received radio energy, and an external power and data logging device having at least one battery and electronic circuitry including a digital memory configured for storing and recalling data. The external power and data logging device has a means for powering the tag, and also has a means.

Temperate Ice Depth-Sounding Radar

NASA Astrophysics Data System (ADS)

Jara-Olivares, V. A.; Player, K.; Rodriguez-Morales, F.; Gogineni, P.

2008-12-01

Glaciers in several parts of the world are reported to be retreating and thinning rapidly over the last decade. Radar instruments can be used to provide a wealth of information regarding the internal and basal conditions of large and small ice masses. These instruments typically operate in the VHF and UHF regions of the electromagnetic spectrum. For temperate-ice sounding, however, the high water content produces scattering and attenuation in propagating radar waves at VHF and UHF frequencies, which significantly reduce the penetration depths. Radars operating in the HF band are better suited for systematic surveys of the thickness and sub-glacial topography of temperate-ice regions. We are developing a dual-frequency Temperate-Ice-Depth Sounding Radar (TIDSoR) that can penetrate through water pockets, thus providing more accurate measurements of temperate ice properties such as thickness and basal conditions. The radar is a light-weight, low power consumption portable system for surface-based observations in mountainous terrain or aerial surveys. TIDSoR operates at two different center frequencies: 7.7 MHz and 14 MHz, with a maximum output peak power of 20 W. The transmit waveform is a digitally generated linear frequency-modulated chirp with 1 MHz bandwidth. The radar can be installed on aircrafts such as the CReSIS UAV [1], DCH-6 (Twin Otter), or P-3 Orion for aerial surveys, where it could be supported by the airplane power system. For surface based experiments, TIDSoR can operate in a backpack configuration powered by a compact battery system. The system can also be installed on a sled towed by a motorized vehicle, in which case the power supply can be replaced by a diesel generator. The radar consists of three functional blocks: the digital section, the radio-frequency (RF) section, and the antenna, and is designed to weigh less than 2 kg, excluding the power supply. The digital section generates the transmit waveforms as well as timing and control signals. It also digitizes the output signal from the receiver and stores the data in binary format using a portable computer. The RF-section consists of a high- power transmitter and a low-noise receiver with digitally controlled variable gain. The antenna is time-shared between the transmitter and receiver by means of a transmit/receive (T/R) switch. In regards to the antenna, we have made a survey study of various electrically small antennas (ESA) to choose the most suitable radiating structure for this application. Among the different alternatives that provide a good trade-off between electrical performance and small size, we have adopted an ESA dipole configuration for airborne platforms and a half-wavelength radiator for the surface-based version. The airborne antenna solution is given after studying the geometry of the aerial vehicle and its fuselage contribution to the antenna radiation pattern. Dipoles are made of 11.6 mm diameter cables (AWG 0000) or printed patches embedded into the aircraft fuselage, wings, or both. The system is currently being integrated and tested. TIDSoR is expected to be deployed during the spring 2008 either in Alaska or Greenland for surface based observations. In this paper, we will discuss our design considerations and current progress towards the development of this radar system. [1] Center for Remote Sensing of Ice Sheets (Cresis), Sept 2008, [Online]. Available: http://www.cresis.ku.edu

Design and characterization of the PREC (Prototype Readout Electronics for Counting particles)

NASA Astrophysics Data System (ADS)

Assis, P.; Brogueira, P.; Ferreira, M.; Luz, R.; Mendes, L.

2016-08-01

The design, tests and performance of a novel, low noise, acquisition system—the PREC (Prototype Readout Electronics for Counting particles) is presented in this article. PREC is a system developed using discrete electronics for particle counting applications using RPCs (Resistive Plate Chamber) detectors. PREC can, however, be used with other kind of detectors that present fast pulses, e.g. Silicon Photomultipliers. The PREC system consists in several Front-End boards that transmit data to a purely digital Motherboard. The amplification and discrimination of the signal is performed in the Front-End boards, making them the critical component of the system. In this paper, the Front-End was tested extensively by measuring the gain, noise level, crosstalk, trigger efficiency, propagation time and power consumption. The gain shows a decrease with the working temperature and an increase with the power supply voltage. The Front-End board shows a low noise level (<= 1.6 mV at 3σ level) and no crosstalk is detected above this level. The s-curve of the trigger efficiency is characterized by a 3 mV gap from the region where most of the signals are triggered to almost no signal is triggered. The signal transit time between the Front-End input and the digital Motherboard is estimated to be 5.82 ns. The maximum power consumption is 3.372 W for the Motherboard and 3.576 W and 1.443 W for each Front-End analogue circuitry and digital part, respectively.

A Remote Monitoring System for Voltage, Current, Power and Temperature Measurements

NASA Astrophysics Data System (ADS)

Barakat, E.; Sinno, N.; Keyrouz, C.

This paper presents a study and design of a monitoring system for the continuous measurement of electrical energy parameters such as voltage, current, power and temperature. This system is designed to monitor the data remotely over internet. The electronic power meter is based on a microcontroller from Microchip Technology Inc. PIC family. The design takes into consideration the correct operation in the event of an outage or brown out by recording the electrical values and the temperatures in EEPROM internally available in the microcontroller. Also a digital display is used to show the acquired measurements. A computer will remotely monitor the data over internet.

Research study on multi-KW-DC distribution system

NASA Technical Reports Server (NTRS)

Berkery, E. A.; Krausz, A.

1975-01-01

A detailed definition of the HVDC test facility and the equipment required to implement the test program are provided. The basic elements of the test facility are illustrated, and consist of: the power source, conventional and digital supervision and control equipment, power distribution harness and simulated loads. The regulated dc power supplies provide steady-state power up to 36 KW at 120 VDC. Power for simulated line faults will be obtained from two banks of 90 ampere-hour lead-acid batteries. The relative merits of conventional and multiplexed power control will be demonstrated by the Supervision and Monitor Unit (SMU) and the Automatically Controlled Electrical Systems (ACES) hardware. The distribution harness is supported by a metal duct which is bonded to all component structures and functions as the system ground plane. The load banks contain passive resistance and reactance loads, solid state power controllers and active pulse width modulated loads. The HVDC test facility is designed to simulate a power distribution system for large aerospace vehicles.

Flexible circuits with integrated switches for robotic shape sensing

NASA Astrophysics Data System (ADS)

Harnett, C. K.

2016-05-01

Digital switches are commonly used for detecting surface contact and limb-position limits in robotics. The typical momentary-contact digital switch is a mechanical device made from metal springs, designed to connect with a rigid printed circuit board (PCB). However, flexible printed circuits are taking over from the rigid PCB in robotics because the circuits can bend while carrying signals and power through moving joints. This project is motivated by a previous work where an array of surface-mount momentary contact switches on a flexible circuit acted as an all-digital shape sensor compatible with the power resources of energy harvesting systems. Without a rigid segment, the smallest commercially-available surface-mount switches would detach from the flexible circuit after several bending cycles, sometimes violently. This report describes a low-cost, conductive fiber based method to integrate electromechanical switches into flexible circuits and other soft, bendable materials. Because the switches are digital (on/off), they differ from commercially-available continuous-valued bend/flex sensors. No amplification or analog-to-digital conversion is needed to read the signal, but the tradeoff is that the digital switches only give a threshold curvature value. Boundary conditions on the edges of the flexible circuit are key to setting the threshold curvature value for switching. This presentation will discuss threshold-setting, size scaling of the design, automation for inserting a digital switch into the flexible circuit fabrication process, and methods for reconstructing a shape from an array of digital switch states.

Flight evaluation of modifications to a digital electronic engine control system in an F-15 airplane

NASA Technical Reports Server (NTRS)

Burcham, F. W., Jr.; Myers, L. P.; Zeller, J. R.

1983-01-01

The third phase of a flight evaluation of a digital electronic engine control system in an F-15 has recently been completed. It was found that digital electronic engine control software logic changes and augmentor hardware improvements resulted in significant improvements in engine operation. For intermediate to maximum power throttle transients, an increase in altitude capability of up to 8000 ft was found, and for idle to maximum transients, an increase of up to 4000 ft was found. A nozzle instability noted in earlier flight testing was investigated on a test engine at NASA Lewis Research Center, a digital electronic engine control software logic change was developed and evaluated, and no instability occurred in the Phase 3 flight evaluation. The backup control airstart modification was evaluated, and gave an improvement of airstart capability by reducing the minimum airspeed for successful airstarts by 50 to 75 knots.

A VLSI Neural Monitoring System With Ultra-Wideband Telemetry for Awake Behaving Subjects.

PubMed

Greenwald, E; Mollazadeh, M; Hu, C; Wei Tang; Culurciello, E; Thakor, V

2011-04-01

Long-term monitoring of neuronal activity in awake behaving subjects can provide fundamental information about brain dynamics for neuroscience and neuroengineering applications. Here, we present a miniature, lightweight, and low-power recording system for monitoring neural activity in awake behaving animals. The system integrates two custom designed very-large-scale integrated chips, a neural interface module fabricated in 0.5 μm complementary metal-oxide semiconductor technology and an ultra-wideband transmitter module fabricated in a 0.5 μm silicon-on-sapphire (SOS) technology. The system amplifies, filters, digitizes, and transmits 16 channels of neural data at a rate of 1 Mb/s. The entire system, which includes the VLSI circuits, a digital interface board, a battery, and a custom housing, is small and lightweight (24 g) and, thus, can be chronically mounted on small animals. The system consumes 4.8 mA and records continuously for up to 40 h powered by a 3.7-V, 200-mAh rechargeable lithium-ion battery. Experimental benchtop characterizations as well as in vivo multichannel neural recordings from awake behaving rats are presented here.

Digital micromirror based near-infrared illumination system for plasmonic photothermal neuromodulation

PubMed Central

Jung, Hyunjun; Kang, Hongki; Nam, Yoonkey

2017-01-01

Light-mediated neuromodulation techniques provide great advantages to investigate neuroscience due to its high spatial and temporal resolution. To generate a spatial pattern of neural activity, it is necessary to develop a system for patterned-light illumination to a specific area. Digital micromirror device (DMD) based patterned illumination system have been used for neuromodulation due to its simple configuration and design flexibility. In this paper, we developed a patterned near-infrared (NIR) illumination system for region specific photothermal manipulation of neural activity using NIR-sensitive plasmonic gold nanorods (GNRs). The proposed system had high power transmission efficiency for delivering power density up to 19 W/mm2. We used a GNR-coated microelectrode array (MEA) to perform biological experiments using E18 rat hippocampal neurons and showed that it was possible to inhibit neural spiking activity of specific area in neural circuits with the patterned NIR illumination. This patterned NIR illumination system can serve as a promising neuromodulation tool to investigate neuroscience in a wide range of physiological and clinical applications. PMID:28663912

Analog pulse processor

DOEpatents

Wessendorf, Kurt O.; Kemper, Dale A.

2003-06-03

A very low power analog pulse processing system implemented as an ASIC useful for processing signals from radiation detectors, among other things. The system incorporates the functions of a charge sensitive amplifier, a shaping amplifier, a peak sample and hold circuit, and, optionally, an analog to digital converter and associated drivers.

A low power flash-FPGA based brain implant micro-system of PID control.

PubMed

Lijuan Xia; Fattah, Nabeel; Soltan, Ahmed; Jackson, Andrew; Chester, Graeme; Degenaar, Patrick

2017-07-01

In this paper, we demonstrate that a low power flash FPGA based micro-system can provide a low power programmable interface for closed-loop brain implant inter- faces. The proposed micro-system receives recording local field potential (LFP) signals from an implanted probe, performs closed-loop control using a first order control system, then converts the signal into an optogenetic control stimulus pattern. Stimulus can be implemented through optoelectronic probes. The long term target is for both fundamental neuroscience applications and for clinical use in treating epilepsy. Utilizing our device, closed-loop processing consumes only 14nJ of power per PID cycle compared to 1.52μJ per cycle for a micro-controller implementation. Compared to an application specific digital integrated circuit, flash FPGA's are inherently programmable.

Simultaneous Wireless Power Transfer and Data Communication Using Synchronous Pulse-Controlled Load Modulation.

PubMed

Mao, Shitong; Wang, Hao; Zhu, Chunbo; Mao, Zhi-Hong; Sun, Mingui

2017-10-01

Wireless Power Transfer (WPT) and wireless data communication are both important problems of research with various applications, especially in medicine. However, these two problems are usually studied separately. In this work, we present a joint study of both problems. Most medical electronic devices, such as smart implants, must have both a power supply to allow continuous operation and a communication link to pass information. Traditionally, separate wireless channels for power transfer and communication are utilized, which complicate the system structure, increase power consumption and make device miniaturization difficult. A more effective approach is to use a single wireless link with both functions of delivering power and passing information. We present a design of such a wireless link in which power and data travel in opposite directions. In order to aggressively miniaturize the implant and reduce power consumption, we eliminate the traditional multi-bit Analog-to-Digital Converter (ADC), digital memory and data transmission circuits all together. Instead, we use a pulse stream, which is obtained from the original biological signal, by a sigma-delta converter and an edge detector, to alter the load properties of the WPT channel. The resulting WPT signal is synchronized with the load changes therefore requiring no memory elements to record inter-pulse intervals. We take advantage of the high sensitivity of the resonant WPT to the load change, and the system dynamic response is used to transfer each pulse. The transient time of the WPT system is analyzed using the coupling mode theory (CMT). Our experimental results show that the memoryless approach works well for both power delivery and data transmission, providing a new wireless platform for the design of future miniaturized medical implants.

Energy-efficient digital and wireless IC design for wireless smart sensing

NASA Astrophysics Data System (ADS)

Zhou, Jun; Huang, Xiongchuan; Wang, Chao; Tae-Hyoung Kim, Tony; Lian, Yong

2017-10-01

Wireless smart sensing is now widely used in various applications such as health monitoring and structural monitoring. In conventional wireless sensor nodes, significant power is consumed in wirelessly transmitting the raw data. Smart sensing adds local intelligence to the sensor node and reduces the amount of wireless data transmission via on-node digital signal processing. While the total power consumption is reduced compared to conventional wireless sensing, the power consumption of the digital processing becomes as dominant as wireless data transmission. This paper reviews the state-of-the-art energy-efficient digital and wireless IC design techniques for reducing the power consumption of the wireless smart sensor node to prolong battery life and enable self-powered applications.

New York State Police remote communications site small wind energy conversion system. Final report

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

Not Available

1985-03-01

This report concludes a year-long demonstration and study of the use of a North Wind Model HR2 wind energy conversion system to supply the power for a remote New York State Police microwave repeater site at Mt. Morris in the Adirondack Mountains. Data were collected on a multi-channel digital strip chart recorder which provided a printout of the real-time relation between windspeed, power output, battery capacity and voltage, and contribution from backup power. These data proved that the site could be run on wind power alone and predictions can now be made on the performance of an HR2 or similarmore » wind system at other sites. 5 figs., 1 tab.« less

SP-100 Control System Design

NASA Astrophysics Data System (ADS)

Shukla, Jaikaran N.; Halfen, Frank J.; Brynsvold, Glen V.; Syed, Akbar; Jiang, Thomas J.; Wong, Kwok K.; Otwell, Robert L.

1994-07-01

Recent work in lower power generic early applications for the SP-100 have resulted in control system design simplification for a 20 kWe design with thermoelectric power conversion. This paper presents the non-mission-dependent control system features for this design. The control system includes a digital computer based controller, dual purpose control rods and drives, temperature sensors, and neutron flux monitors. The thaw system is mission dependent and can be either electrical or based on NaK trace lines. Key features of the control system and components are discussed. As was the case for higher power applications, the initial on-orbit approach to criticality involves the relatively fast withdrawal of the control-rods to a near-critical position followed by slower movement through critical and into the power range. The control system performs operating maneuvers as well as providing for automatic startup, shutdown, restart, and reactor protection.

Power feasibility of implantable digital spike sorting circuits for neural prosthetic systems.

PubMed

Zumsteg, Zachary S; Kemere, Caleb; O'Driscoll, Stephen; Santhanam, Gopal; Ahmed, Rizwan E; Shenoy, Krishna V; Meng, Teresa H

2005-09-01

A new class of neural prosthetic systems aims to assist disabled patients by translating cortical neural activity into control signals for prosthetic devices. Based on the success of proof-of-concept systems in the laboratory, there is now considerable interest in increasing system performance and creating implantable electronics for use in clinical systems. A critical question that impacts system performance and the overall architecture of these systems is whether it is possible to identify the neural source of each action potential (spike sorting) in real-time and with low power. Low power is essential both for power supply considerations and heat dissipation in the brain. In this paper we report that state-of-the-art spike sorting algorithms are not only feasible using modern complementary metal oxide semiconductor very large scale integration processes, but may represent the best option for extracting large amounts of data in implantable neural prosthetic interfaces.

A MEMS and agile optics-based dual-mode variable optical power splitter with no moving parts

NASA Astrophysics Data System (ADS)

Khwaja, Tariq S.; Suleman, Hamid; Reza, Syed Azer

2017-06-01

In this paper, we present a novel design of an optical power splitter. Owing to the inherent variable power split ratios that the proposed design delivers, it is ideal for use in communications, sensing and signal processing applications where variable power splitting is often quintessential. The proposed power splitter module is dual mode as it combines the use of a Micro-Electro-Mechanical Systems (MEMS) based Digital Micro-mirror Device (DMD) and an Electronically Controlled Tunable Lens (ECTL) to split the power of an input optical signal between two output ports - the designated port and the surplus port. The use of a reflective Digital Spatial Light Modulator (DSLM) such as the DMD provides a motion-free digital control of the split ratio between the two output ports. Although the digital step between two possible successive split ratios can be fairly minimal with the use of a high resolution DMD but it is a challenge to correctly ascertain the exact image pattern on the DMD to obtain any desired specific split ratio. To counter this challenge, we propose the synchronized use of a circular pattern on the DMD, which serves as a circular clear aperture with a tunable radius, and an ECTL. The radius of the circular pattern on the DMD provides a digital control of the split ratio between the two ports whereas the ECTL, depending on its controller, can provide either an analog or a digital control by altering the beam radius which is incident at the DMD circular pattern. The radius of the circular pattern on the DMD can be minimally changed by one micro-pixel thickness. Setting the radius of the circular pattern on the DMD to an appropriate value provides the closest "ball-park" split ratio whereas further tuning the ECTL aids in slightly altering from this digitally set value to obtain the exact desired split ratio in-between any two digitally-set successive split ratios that correspond to any clear aperture radius of the DMD pattern and its incremental minimal allowable change of one micropixel. We provide a detailed scheme to calculate the desired DMD aperture radius as well as the focal length setting of the ECTL to obtain any given split ratio. By setting tolerance limits on the split ratio, we also show that our method affords diversity by providing multiple possible solutions to achieve a desired optical power split ratio within the specified tolerances. We also demonstrate the validation of the proposed concept with initial experimental results and discussions. These experimental results show a repeatable splitter operation and the resulting power split ratios according to the theoretical predictions. With the experimental data, we also demonstrate the effectiveness of the method in obtaining any particular split ratio through different DMD and ECTL configurations with specific split ratio tolerance values.

21 CFR 1311.45 - Requirements for registrants that allow powers of attorney to obtain CSOS digital certificates...

Code of Federal Regulations, 2010 CFR

2010-04-01

... attorney to obtain CSOS digital certificates under their DEA registration. 1311.45 Section 1311.45 Food and... PRESCRIPTIONS (Eff. 6-1-10) Obtaining and Using Digital Certificates for Electronic Orders § 1311.45 Requirements for registrants that allow powers of attorney to obtain CSOS digital certificates under their DEA...

Development of targeted STORM for super resolution imaging of biological samples using digital micro-mirror device

NASA Astrophysics Data System (ADS)

Valiya Peedikakkal, Liyana; Steventon, Victoria; Furley, Andrew; Cadby, Ashley J.

2017-12-01

We demonstrate a simple illumination system based on a digital mirror device which allows for fine control over the power and pattern of illumination. We apply this to localization microscopy (LM), specifically stochastic optical reconstruction microscopy (STORM). Using this targeted STORM, we were able to image a selected area of a labelled cell without causing photo-damage to the surrounding areas of the cell.

Description of real-time Ada software implementation of a power system monitor for the Space Station Freedom PMAD DC testbed

NASA Technical Reports Server (NTRS)

Ludwig, Kimberly; Mackin, Michael; Wright, Theodore

1991-01-01

The authors describe the Ada language software developed to perform the electrical power system monitoring functions for the NASA Lewis Research Center's Power Management and Distribution (PMAD) DC testbed. The results of the effort to implement this monitor are presented. The PMAD DC testbed is a reduced-scale prototype of the electric power system to be used in Space Station Freedom. The power is controlled by smart switches known as power control components (or switchgear). The power control components are currently coordinated by five Compaq 386/20e computers connected through an 802.4 local area network. The power system monitor algorithm comprises several functions, including periodic data acquisition, data smoothing, system performance analysis, and status reporting. Data are collected from the switchgear sensors every 100 ms, then passed through a 2-Hz digital filter. System performance analysis includes power interruption and overcurrent detection. The system monitor required a hardware timer interrupt to activate the data acquisition function. The execution time of the code was optimized by using an assembly language routine. The routine allows direct vectoring of the processor to Ada language procedures that perform periodic control activities.

47 CFR 15.103 - Exempted devices.

Code of Federal Regulations, 2011 CFR

2011-10-01

... exclusively as an electronic control or power system utilized by a public utility or in an industrial plant... circuit to convert the signal to the format required (e.g., an integrated circuit for analog to digital...

47 CFR 15.103 - Exempted devices.

Code of Federal Regulations, 2010 CFR

2010-10-01

... exclusively as an electronic control or power system utilized by a public utility or in an industrial plant... circuit to convert the signal to the format required (e.g., an integrated circuit for analog to digital...

47 CFR 15.103 - Exempted devices.

Code of Federal Regulations, 2013 CFR

2013-10-01

... exclusively as an electronic control or power system utilized by a public utility or in an industrial plant... circuit to convert the signal to the format required (e.g., an integrated circuit for analog to digital...

47 CFR 15.103 - Exempted devices.

Code of Federal Regulations, 2014 CFR

2014-10-01

... exclusively as an electronic control or power system utilized by a public utility or in an industrial plant... circuit to convert the signal to the format required (e.g., an integrated circuit for analog to digital...

47 CFR 15.103 - Exempted devices.

Code of Federal Regulations, 2012 CFR

2012-10-01

... exclusively as an electronic control or power system utilized by a public utility or in an industrial plant... circuit to convert the signal to the format required (e.g., an integrated circuit for analog to digital...

A closed-loop compressive-sensing-based neural recording system.

PubMed

Zhang, Jie; Mitra, Srinjoy; Suo, Yuanming; Cheng, Andrew; Xiong, Tao; Michon, Frederic; Welkenhuysen, Marleen; Kloosterman, Fabian; Chin, Peter S; Hsiao, Steven; Tran, Trac D; Yazicioglu, Firat; Etienne-Cummings, Ralph

2015-06-01

This paper describes a low power closed-loop compressive sensing (CS) based neural recording system. This system provides an efficient method to reduce data transmission bandwidth for implantable neural recording devices. By doing so, this technique reduces a majority of system power consumption which is dissipated at data readout interface. The design of the system is scalable and is a viable option for large scale integration of electrodes or recording sites onto a single device. The entire system consists of an application-specific integrated circuit (ASIC) with 4 recording readout channels with CS circuits, a real time off-chip CS recovery block and a recovery quality evaluation block that provides a closed feedback to adaptively adjust compression rate. Since CS performance is strongly signal dependent, the ASIC has been tested in vivo and with standard public neural databases. Implemented using efficient digital circuit, this system is able to achieve >10 times data compression on the entire neural spike band (500-6KHz) while consuming only 0.83uW (0.53 V voltage supply) additional digital power per electrode. When only the spikes are desired, the system is able to further compress the detected spikes by around 16 times. Unlike other similar systems, the characteristic spikes and inter-spike data can both be recovered which guarantes a >95% spike classification success rate. The compression circuit occupied 0.11mm(2)/electrode in a 180nm CMOS process. The complete signal processing circuit consumes <16uW/electrode. Power and area efficiency demonstrated by the system make it an ideal candidate for integration into large recording arrays containing thousands of electrode. Closed-loop recording and reconstruction performance evaluation further improves the robustness of the compression method, thus making the system more practical for long term recording.

Millimeterwave and digital applications of InP-based MBE grown HEMTs and HBTs

NASA Astrophysics Data System (ADS)

Greiling, Paul

1997-05-01

Microwave and millimeterwave devices grown by MBE have significantly advanced the state of the art for RF device performance with respect to noise figure, power output, power added efficiency and extended the clock frequency of digital circuits into the millimeterwave regime. Ober the last 10-15 years, military systems have greatly benefited from the superior performance of MBE grown devices. In order to have a similar impact on the commercial marketplace, MBE growers will have to focus their efforts on a different set of performance criteria; i.e. cost, uniformity and reproducibility. This paper discusses outstanding performance achieved by MBE grown devices and outlines the criteria for commercial applications.

Low-power SXGA active matrix OLED

NASA Astrophysics Data System (ADS)

Wacyk, Ihor; Prache, Olivier; Ghosh, Amal

2009-05-01

This paper presents the design and first evaluation of a full-color 1280×3×1024 pixel, active matrix organic light emitting diode (AMOLED) microdisplay that operates at a low power of 200mW under typical operating conditions of 35fL, and offers a precision 30-bit RGB digital interface in a compact size (0.78-inch diagonal active area). The new system architecture developed by eMagin for the SXGA microdisplay, based on a separate FPGA driver and AMOLED display chip, offers several benefits, including better power efficiency, cost-effectiveness, more features for improved performance, and increased system flexibility.

Application of the MNA design method to a nonlinear turbofan engine. [multivariable Nyquist array method

NASA Technical Reports Server (NTRS)

Leininger, G. G.

1981-01-01

Using nonlinear digital simulation as a representative model of the dynamic operation of the QCSEE turbofan engine, a feedback control system is designed by variable frequency design techniques. Transfer functions are generated for each of five power level settings covering the range of operation from approach power to full throttle (62.5% to 100% full power). These transfer functions are then used by an interactive control system design synthesis program to provide a closed loop feedback control using the multivariable Nyquist array and extensions to multivariable Bode diagrams and Nichols charts.

No short-term effects of digital mobile radio telephone on the awake human electroencephalogram

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

Roeschke, J.; Mann, K.

1997-05-01

A recent study reported the results of an exploratory study of alterations of the quantitative sleep profile due to the effects of a digital mobile radio telephone. Rapid eye movement (REM) was suppressed, and the spectral power density in the 8--13 Hz frequency range during REM sleep was altered. The aim of the present study was to illuminate the influence of digital mobile radio telephone on the awake electroencephalogram (EEG) of healthy subjects. For this purpose, the authors investigated 34 male subjects in a single-blind cross-over design experiment by measuring spontaneous EEGs under closed-eyes condition from scalp positions C{sub 3}more » and C{sub 4} and comparing the effects of an active and an inactive digital mobile radio telephone (GSM) system. During exposure of nearly 3.5 min to the 900 MHz electromagnetic field pulsed at a frequency of 217 Hz and with a pulse width of 580 {micro}s, the authors could not detect any difference in the awake EEGs in terms of spectral power density measures.« less

Fast front-end electronics for semiconductor tracking detectors: Trends and perspectives

NASA Astrophysics Data System (ADS)

Rivetti, Angelo

2014-11-01

In the past few years, extensive research efforts pursued by both the industry and the academia have lead to major improvements in the performance of Analog to Digital Converters (ADCs) and Time to Digital Converters (TDCs). ADCs achieving 8-10 bit resolution, 50-100 MHz conversion frequency and less than 1 mW power consumption are the today's standard, while TDCs have reached sub-picosecond time resolution. These results have been made possible by architectural upgrades combined with the use of ultra deep submicron CMOS technologies with minimum feature size of 130 nm or smaller. Front-end ASICs in which a prompt digitization is followed by signal conditioning in the digital domain can now be envisaged also within the tight power budget typically available in high density tracking systems. Furthermore, tracking detectors embedding high resolution timing capabilities are gaining interest. In the paper, ADC's and TDC's developments which are of particular relevance for the design front-end electronics for semiconductor trackers are discussed along with the benefits and challenges of exploiting such high performance building blocks in implementing the next generation of ASICs for high granularity particle detectors.

Nuclear Power Plant Cyber Security Discrete Dynamic Event Tree Analysis (LDRD 17-0958) FY17 Report

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

Wheeler, Timothy A.; Denman, Matthew R.; Williams, R. A.

Instrumentation and control of nuclear power is transforming from analog to modern digital assets. These control systems perform key safety and security functions. This transformation is occurring in new plant designs as well as in the existing fleet of plants as the operation of those plants is extended to 60 years. This transformation introduces new and unknown issues involving both digital asset induced safety issues and security issues. Traditional nuclear power risk assessment tools and cyber security assessment methods have not been modified or developed to address the unique nature of cyber failure modes and of cyber security threat vulnerabilities.more » iii This Lab-Directed Research and Development project has developed a dynamic cyber-risk in- formed tool to facilitate the analysis of unique cyber failure modes and the time sequencing of cyber faults, both malicious and non-malicious, and impose those cyber exploits and cyber faults onto a nuclear power plant accident sequence simulator code to assess how cyber exploits and cyber faults could interact with a plants digital instrumentation and control (DI&C) system and defeat or circumvent a plants cyber security controls. This was achieved by coupling an existing Sandia National Laboratories nuclear accident dynamic simulator code with a cyber emulytics code to demonstrate real-time simulation of cyber exploits and their impact on automatic DI&C responses. Studying such potential time-sequenced cyber-attacks and their risks (i.e., the associated impact and the associated degree of difficulty to achieve the attack vector) on accident management establishes a technical risk informed framework for developing effective cyber security controls for nuclear power.« less

10 CFR 73.55 - Requirements for physical protection of licensed activities in nuclear power reactors against...

Code of Federal Regulations, 2011 CFR

2011-01-01

... integration of systems, technologies, programs, equipment, supporting processes, and implementing procedures...-in-depth methodologies to minimize the potential for an insider to adversely affect, either directly... protection of digital computer and communication systems and networks. (ii) Site-specific conditions that...

Automated Cryocooler Monitor and Control System

NASA Technical Reports Server (NTRS)

Britcliffe, Michael J.; Hanscon, Theodore R.; Fowler, Larry E.

2011-01-01

A system was designed to automate cryogenically cooled low-noise amplifier systems used in the NASA Deep Space Network. It automates the entire operation of the system including cool-down, warm-up, and performance monitoring. The system is based on a single-board computer with custom software and hardware to monitor and control the cryogenic operation of the system. The system provides local display and control, and can be operated remotely via a Web interface. The system controller is based on a commercial single-board computer with onboard data acquisition capability. The commercial hardware includes a microprocessor, an LCD (liquid crystal display), seven LED (light emitting diode) displays, a seven-key keypad, an Ethernet interface, 40 digital I/O (input/output) ports, 11 A/D (analog to digital) inputs, four D/A (digital to analog) outputs, and an external relay board to control the high-current devices. The temperature sensors used are commercial silicon diode devices that provide a non-linear voltage output proportional to temperature. The devices are excited with a 10-microamp bias current. The system is capable of monitoring and displaying three temperatures. The vacuum sensors are commercial thermistor devices. The output of the sensors is a non-linear voltage proportional to vacuum pressure in the 1-Torr to 1-millitorr range. Two sensors are used. One measures the vacuum pressure in the cryocooler and the other the pressure at the input to the vacuum pump. The helium pressure sensor is a commercial device that provides a linear voltage output from 1 to 5 volts, corresponding to a gas pressure from 0 to 3.5 MPa (approx. = 500 psig). Control of the vacuum process is accomplished with a commercial electrically operated solenoid valve. A commercial motor starter is used to control the input power of the compressor. The warm-up heaters are commercial power resistors sized to provide the appropriate power for the thermal mass of the particular system, and typically provide 50 watts of heat. There are four basic operating modes. "Cool " mode commands the system to cool to normal operating temperature. "Heat " mode is used to warm the device to a set temperature near room temperature. "Pump " mode is a maintenance function that allows the vacuum system to be operated alone to remove accumulated contaminants from the vacuum area. In "Off " mode, no power is applied to the system.

Applying Human Factors Evaluation and Design Guidance to a Nuclear Power Plant Digital Control System

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

Thomas Ulrich; Ronald Boring; William Phoenix

2012-08-01

The United States (U.S.) nuclear industry, like similar process control industries, has moved toward upgrading its control rooms. The upgraded control rooms typically feature digital control system (DCS) displays embedded in the panels. These displays gather information from the system and represent that information on a single display surface. In this manner, the DCS combines many previously separate analog indicators and controls into a single digital display, whereby the operators can toggle between multiple windows to monitor and control different aspects of the plant. The design of the DCS depends on the function of the system it monitors, but revolvesmore » around presenting the information most germane to an operator at any point in time. DCSs require a carefully designed human system interface. This report centers on redesigning existing DCS displays for an example chemical volume control system (CVCS) at a U.S. nuclear power plant. The crucial nature of the CVCS, which controls coolant levels and boration in the primary system, requires a thorough human factors evaluation of its supporting DCS. The initial digital controls being developed for the DCSs tend to directly mimic the former analog controls. There are, however, unique operator interactions with a digital vs. analog interface, and the differences have not always been carefully factored in the translation of an analog interface to a replacement DCS. To ensure safety, efficiency, and usability of the emerging DCSs, a human factors usability evaluation was conducted on a CVCS DCS currently being used and refined at an existing U.S. nuclear power plant. Subject matter experts from process control engineering, software development, and human factors evaluated the DCS displays to document potential usability issues and propose design recommendations. The evaluation yielded 167 potential usability issues with the DCS. These issues should not be considered operator performance problems but rather opportunities identified by experts to improve upon the design of the DCS. A set of nine design recommendations was developed to address these potential issues. The design principles addressed the following areas: (1) color, (2) pop-up window structure, (3) navigation, (4) alarms, (5) process control diagram, (6) gestalt grouping, (7) typography, (8) terminology, and (9) data entry. Visuals illustrating the improved DCS displays accompany the design recommendations. These nine design principles serve as the starting point to a planned general DCS style guide that can be used across the U.S. nuclear industry to aid in the future design of effective DCS interfaces.« less

Performance analysis of ‘Perturb and Observe’ and ‘Incremental Conductance’ MPPT algorithms for PV system

NASA Astrophysics Data System (ADS)

Lodhi, Ehtisham; Lodhi, Zeeshan; Noman Shafqat, Rana; Chen, Fieda

2017-07-01

Photovoltaic (PV) system usually employed The Maximum power point tracking (MPPT) techniques for increasing its efficiency. The performance of the PV system perhaps boosts by controlling at its apex point of power, in this way maximal power can be given to load. The proficiency of a PV system usually depends upon irradiance, temperature and array architecture. PV array shows a non-linear style for V-I curve and maximal power point on V-P curve also varies with changing environmental conditions. MPPT methods grantees that a PV module is regulated at reference voltage and to produce entire usage of the maximal output power. This paper gives analysis between two widely employed Perturb and Observe (P&O) and Incremental Conductance (INC) MPPT techniques. Their performance is evaluated and compared through theoretical analysis and digital simulation on the basis of response time and efficiency under varying irradiance and temperature condition using Matlab/Simulink.

QCSEE UTW engine powered-lift acoustic performance

NASA Technical Reports Server (NTRS)

Loeffler, I. J.; Samanich, N. E.; Bloomer, H. E.

1980-01-01

Powered-lift acoustic test of the Quiet Clean Short Haul Experimental Engine (QCSEE) under the wing (UTW) engine are reported. Propulsion systems for two powered-lift concepts were designed, fabricated, and tested. In addition to low noise features, the designs included composite structures, gear-driven fans, digital control, and a variable pitch fan (UTW). The UTW engine was tested in a static ground test facility with wing and flap segments to simulate installation on a short haul transport aircraft of the future. Powered-lift acoustic performance of the UTW engine is compared with that of the previously tested and reported QCSEE over-the-wing (OTW) engine. Both engines were slightly above the noise goal but were significantly below current FAA and modern wide-body jet transport levels. The UTW system in the powered-lift mode was penalized by reflected engine noise from the wing and flap system, while the OTW system was benefitted by a wing noise shielding effect.

A wide bandwidth CCD buffer memory system

NASA Technical Reports Server (NTRS)

Siemens, K.; Wallace, R. W.; Robinson, C. R.

1978-01-01

A prototype system was implemented to demonstrate that CCD's can be applied advantageously to the problem of low power digital storage and particularly to the problem of interfacing widely varying data rates. CCD shift register memories (8K bit) were used to construct a feasibility model 128 K-bit buffer memory system. Serial data that can have rates between 150 kHz and 4.0 MHz can be stored in 4K-bit, randomly-accessible memory blocks. Peak power dissipation during a data transfer is less than 7 W, while idle power is approximately 5.4 W. The system features automatic data input synchronization with the recirculating CCD memory block start address. System expansion to accommodate parallel inputs or a greater number of memory blocks can be performed in a modular fashion. Since the control logic does not increase proportionally to increase in memory capacity, the power requirements per bit of storage can be reduced significantly in a larger system.

Device and method for measuring the coefficient of performance of a heat pump

DOEpatents

Brantley, V.R.; Miller, D.R.

1982-05-18

A method and instrument is provided which allows quick and accurate measurement of the coefficient of performance of an installed electrically powered heat pump including auxiliary resistane heaters. Temperature-sensitive resistors are placed in the return and supply air ducts to measure the temperature increase of the air across the refrigerant and resistive-heating elements of the system. The voltages across the resistors which are directly proportional to the respective duct tempertures are applied to the inputs of a differential amplifier so that its output voltage is proportional to the temperature difference across the unit. A voltage-to-frequency converter connected to the output of the differential amplifier converts the voltage signal to a proportional-frequency signal. A digital watt meter is used to measure the power to the unit and produces a signal having a frequency proportional to the input power. A digital logic circuit ratios the temperature difference signal and the electric power input signal in a unique manner to produce a single number which is the coefficient of performance of the unit over the test interval. The digital logic and an in-situ calibration procedure enables the instrument to make these measurements in such a way that the ratio of heat flow/power input is obtained without computations. No specialized knowledge of thermodynamics or electrons is required to operate the instrument.

Device and method for measuring the coefficient of performance of a heat pump

DOEpatents

Brantley, Vanston R.; Miller, Donald R.

1984-01-01

A method and instrument is provided which allows quick and accurate measurement of the coefficient of performance of an installed electrically powered heat pump including auxiliary resistance heaters. Temperature sensitive resistors are placed in the return and supply air ducts to measure the temperature increase of the air across the refrigerant and resistive heating elements of the system. The voltages across the resistors which are directly proportional to the respective duct temperatures are applied to the inputs of a differential amplifier so that its output voltage is proportional to the temperature difference across the unit. A voltage-to-frequency converter connected to the output of the differential amplifier converts the voltage signal to a proportional frequency signal. A digital watt meter is used to measure the power to the unit and produces a signal having a frequency proportional to the input power. A digital logic circuit ratios the temperature difference signal and the electric power input signal in a unique manner to produce a single number which is the coefficient of performance of the unit over the test interval. The digital logic and an in-situ calibration procedure enables the instrument to make these measurements in such a way that the ratio of heat flow/power input is obtained without computations. No specialized knowledge of thermodynamics or electronics is required to operate the instrument.

System and method for simultaneously collecting serial number information from numerous identity tags

DOEpatents

Doty, Michael A.

1997-01-01

A system and method for simultaneously collecting serial number information reports from numerous colliding coded-radio-frequency identity tags. Each tag has a unique multi-digit serial number that is stored in non-volatile RAM. A reader transmits an ASCII coded "D" character on a carrier of about 900 MHz and a power illumination field having a frequency of about 1.6 Ghz. A one MHz tone is modulated on the 1.6 Ghz carrier as a timing clock for a microprocessor in each of the identity tags. Over a thousand such tags may be in the vicinity and each is powered-up and clocked by the 1.6 Ghz power illumination field. Each identity tag looks for the "D" interrogator modulated on the 900 MHz carrier, and each uses a digit of its serial number to time a response. Clear responses received by the reader are repeated for verification. If no verification or a wrong number is received by any identity tag, it uses a second digital together with the first to time out a more extended period for response. Ultimately, the entire serial number will be used in the worst case collision environments; and since the serial numbers are defined as being unique, the final possibility will be successful because a clear time-slot channel will be available.

System and method for simultaneously collecting serial number information from numerous identity tags

DOEpatents

Doty, M.A.

1997-01-07

A system and method are disclosed for simultaneously collecting serial number information reports from numerous colliding coded-radio-frequency identity tags. Each tag has a unique multi-digit serial number that is stored in non-volatile RAM. A reader transmits an ASCII coded ``D`` character on a carrier of about 900 MHz and a power illumination field having a frequency of about 1.6 Ghz. A one MHz tone is modulated on the 1.6 Ghz carrier as a timing clock for a microprocessor in each of the identity tags. Over a thousand such tags may be in the vicinity and each is powered-up and clocked by the 1.6 Ghz power illumination field. Each identity tag looks for the ``D`` interrogator modulated on the 900 MHz carrier, and each uses a digit of its serial number to time a response. Clear responses received by the reader are repeated for verification. If no verification or a wrong number is received by any identity tag, it uses a second digital together with the first to time out a more extended period for response. Ultimately, the entire serial number will be used in the worst case collision environments; and since the serial numbers are defined as being unique, the final possibility will be successful because a clear time-slot channel will be available. 5 figs.

Advanced 3-V semiconductor technology assessment

NASA Technical Reports Server (NTRS)

Nowogrodzki, M.

1983-01-01

Components required for extensions of currently planned space communications systems are discussed for large antennas, crosslink systems, single sideband systems, Aerostat systems, and digital signal processing. Systems using advanced modulation concepts and new concepts in communications satellites are included. The current status and trends in materials technology are examined with emphasis on bulk growth of semi-insulating GaAs and InP, epitaxial growth, and ion implantation. Microwave solid state discrete active devices, multigigabit rate GaAs digital integrated circuits, microwave integrated circuits, and the exploratory development of GaInAs devices, heterojunction devices, and quasi-ballistic devices is considered. Competing technologies such as RF power generation, filter structures, and microwave circuit fabrication are discussed. The fundamental limits of semiconductor devices and problems in implementation are explored.

New J-STAGE system accelerates digitization and distribution of academic journals from Japan

NASA Astrophysics Data System (ADS)

Sato, Ryuichi; Kubota, Soichi; Aoyama, Kota; Tsuchiya, Eri; Miyagawa, Yoshiyuki

13 years have passed since J-STAGE was launched. At present no one could deny that its user interface and functions were already out of date comparing to foreign established e-journals. So JST has developed a new system called “J-STAGE3” in order to offer better usability and give powerful dissemination of academic papers from Japan. As the result of it, they will be able to enjoy the following things: 1) integration of two databases, Journal@rchive and J-STAGE, 2) new design/interface, 3) introduction of international standard XML format, 4) advanced subscription management, 5) saving cost of publishers, and 6) improving J-STAGE online submission and review system. At the end of March 2011, we conducted a market research on current status of digitization on Japanese society journals. The report told us that digitization ratio of those was 62% in total but it was 34% in humanities/social sciences. Or it was 92% in English journals and 55% in Japanese ones. It means that we need further promotion of digitization. In this paper, we discuss functions and direction of J-STAGE3 as well as our role in promotion of digitization of Japanese society journals.

47 CFR 11.55 - EAS operation during a State or Local Area emergency.

Code of Federal Regulations, 2010 CFR

2010-10-01

... leaks or liquid spills, widespread power failures, industrial explosions, and civil disorders. (1) DBS...); analog cable systems, digital cable systems, and wireless cable systems must comply with § 11.54(b)(6... programming should comply with § 11.54(b)(8). (5) Upon completion of the State or Local Area EAS transmission...

The Use of a Solid State Analog Television Transmitter as a Superconducting Electron Gun Power Amplifier

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

J.G. Kulpin, K.J. Kleman, R.A. Legg

2012-07-01

A solid state analog television transmitter designed for 200 MHz operation is being commissioned as a radio frequency power amplifier on the Wisconsin superconducting electron gun cavity. The amplifier consists of three separate radio frequency power combiner cabinets and one monitor and control cabinet. The transmitter employs rugged field effect transistors built into one kilowatt drawers that are individually hot swappable at maximum continuous power output. The total combined power of the transmitter system is 33 kW at 200 MHz, output through a standard coaxial transmission line. A low level radio frequency system is employed to digitally synthesize the 200more » MHz signal and precisely control amplitude and phase.« less

Integration of tablet technologies in the e-laboratory of cytology: a health technology assessment.

PubMed

Giansanti, Daniele; Pochini, Marco; Giovagnoli, Maria Rosaria

2014-10-01

Although tablet systems are becoming a powerful technology, particularly useful in every application of medical imaging, to date no one has investigated the acceptance and performance of this technology in digital cytology. The specific aims of the work were (1) to design a health technology assessment (HTA) tool to assess, in terms of performance and acceptance, the introduction of tablet technologies (wearable, portable, and non portable) in the e-laboratories of cytology and (2) to test the tool in a first significant application of digital cytology. An HTA tool was proposed operating on a domain of five dimensions of investigation comprising the basic information of the product of digital cytology, the perceived subjective quality of images, the assessment of the virtual navigation on the e-slide, the assessment of the information and communication technologies features, and the diagnostic power. Six e-slides regarding studies of cervicovaginal cytology digitalized by means of an Aperio ( www.aperio.com ) scanner and uploaded onto the www.digitalslide.it Web site were used for testing the methodology on three different network connections. Three experts of cytology successfully tested the methodology on seven tablets found suitable for the study in their own standard configuration. Specific indexes furnished by the tool indicated both a high degree of performance and subjective acceptance of the investigated technology. The HTA tool thus could be useful to investigate new tablet technologies in digital cytology and furnish stakeholders with useful information that may help them make decisions involving the healthcare system. From a global point of view the study demonstrates the feasibility of using the tablet technology in digital cytology.

Development of spectral analysis math models and software program and spectral analyzer, digital converter interface equipment design

NASA Technical Reports Server (NTRS)

Hayden, W. L.; Robinson, L. H.

1972-01-01

Spectral analyses of angle-modulated communication systems is studied by: (1) performing a literature survey of candidate power spectrum computational techniques, determining the computational requirements, and formulating a mathematical model satisfying these requirements; (2) implementing the model on UNIVAC 1230 digital computer as the Spectral Analysis Program (SAP); and (3) developing the hardware specifications for a data acquisition system which will acquire an input modulating signal for SAP. The SAP computational technique uses extended fast Fourier transform and represents a generalized approach for simple and complex modulating signals.

Healthcare @ The Speed of Thought: A digital world needs successful transformative leaders.

PubMed

Tremblay, Ken

2017-09-01

In the wake of transformational change powered by the digital era, resultant leadership challenges and strategies essential for successful change, both tactical and cultural, are linked to defined capabilities within the Systems Transformation domain of the LEADS in a Caring Environment framework. Honed from experience, specific softer leadership behaviours supporting system transformation are both described and reinforced. Further, a matrix combining the LEADS framework capabilities with these more specific behaviours is offered as a planning tool that leaders may reflect upon and map out key activities associated with their sponsorship of significant change.

Quiet Clean Short-haul Experimental Engine (QCSEE)

NASA Technical Reports Server (NTRS)

Willis, W. S.

1979-01-01

The design, fabrication, and testing of two experimental propulsion systems for powered lift transport aircraft are given. The under the wing (UTW) engine was intended for installation in an externally blown flap configuration and the over the wing (OTW) engine for use in an upper surface blowing aircraft. The UTW engine included variable pitch composite fan blades, main reduction gear, composite fan frame and nacelle, and a digital control system. The OTW engine included a fixed pitch fan, composite fan frame, boilerplate nacelle, and a full authority digital control. Many acoustic, pollution, performance, and weight goals were demonstrated.

Design and Performance of the Astro-E/XRS Signal Processing System

NASA Technical Reports Server (NTRS)

Boyce, Kevin R.; Audley, M. D.; Baker, R. G.; Dumonthier, J. J.; Fujimoto, R.; Gendreau, K. C.; Ishisaki, Y.; Kelley, R. L.; Stahle, C. K.; Szymkowiak, A. E.

1999-01-01

We describe the signal processing system of the Astro-E XRS instrument. The Calorimeter Analog Processor (CAP) provides bias and power for the detectors and amplifies the detector signals by a factor of 20,000. The Calorimeter Digital Processor (CDP) performs the digital processing of the calorimeter signals, detecting X-ray pulses and analyzing them by optimal filtering. We describe the operation of pulse detection, Pulse height analysis. and risetime determination. We also discuss performance, including the three event grades (hi-res mid-res, and low-res). anticoincidence detection, counting rate dependence, and noise rejection.

Combinatorial FSK modulation for power-efficient high-rate communications

NASA Technical Reports Server (NTRS)

Wagner, Paul K.; Budinger, James M.; Vanderaar, Mark J.

1991-01-01

Deep-space and satellite communications systems must be capable of conveying high-rate data accurately with low transmitter power, often through dispersive channels. A class of noncoherent Combinatorial Frequency Shift Keying (CFSK) modulation schemes is investigated which address these needs. The bit error rate performance of this class of modulation formats is analyzed and compared to the more traditional modulation types. Candidate modulator, demodulator, and digital signal processing (DSP) hardware structures are examined in detail. System-level issues are also discussed.

Digital filter polychromator for Thomson scattering applications

NASA Astrophysics Data System (ADS)

Solokha, V.; Kurskiev, G.; Mukhin, E.; Tolstyakov, S.; Babinov, N.; Bazhenov, A.; Bukreev, I.; Dmitriev, A.; Kochergin, M.; Koval, A.; Litvinov, A.; Masyukevich, S.; Razdobarin, A.; Samsonov, D.; Semenov, V.; Solovey, V.; Chernakov, P.; Chernakov, Al; Chernakov, An

2018-02-01

Incoherent Thomson scattering diagnostics (TS) is a proven technique capable of reliable and robust instantaneous measurement of electron temperature (T e) and density (n e) local values in wide area of plasma physics experiments: from hall-effect thrusters to tokamaks and stellarators. The TS cross section is very low (˜ 6.7 × 10-30 m2), and the corresponding TS signals, measured in fusion experiments, are usually of ˜10-15 of incident power. This paper represents 6 (7) channel filter polychromator equipped with avalanche photodiodes and low-noise preamplifiers. The incorporated ADC system (5 GS/s, 12 bit) provides digital optical output preventing acquisition system from electromagnetic interferences. The calibration techniques and T e, n e with corresponding errors measured in Globus-M plasma are given for the digital polychromator test-bench.

Developments of FPGA-based digital back-ends for low frequency antenna arrays at Medicina radio telescopes

NASA Astrophysics Data System (ADS)

Naldi, G.; Bartolini, M.; Mattana, A.; Pupillo, G.; Hickish, J.; Foster, G.; Bianchi, G.; Lingua, A.; Monari, J.; Montebugnoli, S.; Perini, F.; Rusticelli, S.; Schiaffino, M.; Virone, G.; Zarb Adami, K.

In radio astronomy Field Programmable Gate Array (FPGA) technology is largely used for the implementation of digital signal processing techniques applied to antenna arrays. This is mainly due to the good trade-off among computing resources, power consumption and cost offered by FPGA chip compared to other technologies like ASIC, GPU and CPU. In the last years several digital backend systems based on such devices have been developed at the Medicina radio astronomical station (INAF-IRA, Bologna, Italy). Instruments like FX correlator, direct imager, beamformer, multi-beam system have been successfully designed and realized on CASPER (Collaboration for Astronomy Signal Processing and Electronics Research, https://casper.berkeley.edu) processing boards. In this paper we present the gained experience in this kind of applications.

Effects of HPA-nonlinearity on a 4-DPSK/OFDM-signal for a digital sound broadcasting signal

NASA Astrophysics Data System (ADS)

Rapp, Christoph

1991-10-01

Orthogonal Frequency Division Multiplexing (OFDM) in conjunction with a 4 Differential Phase Shift Keying (DPSK) modulation format has been proposed for the future Digital Audio Broadcasting system (DAB), that should provide compact disk sound quality in portable, vehicular and fixed receivers. With properly chosen parameters, this system should be appropriate for both terrestrial and satellite transmission. The influence of the nonlinear distorsions introduced by the High Power Amplifier (HPA) of the transmitter is examined. In particular, the degradations in power efficiency due to intermodulation effects and backoff operating, as well as spectral degradations are investigated. It is shown for three different kinds of limiting amplifier models, that even with an output backoff in the region of 5 to 6 dB, the degradation of, for example a 512 carrier 4 DPSK/OFDM system relative to the linear case is below 1.7 dB (Pb = 0.0001), while the regenerated sidelobes of the transmitted spectrum are kept below -20 dB.

Experimental study of PAM-4, CAP-16, and DMT for 100 Gb/s short reach optical transmission systems.

PubMed

Zhong, Kangping; Zhou, Xian; Gui, Tao; Tao, Li; Gao, Yuliang; Chen, Wei; Man, Jiangwei; Zeng, Li; Lau, Alan Pak Tao; Lu, Chao

2015-01-26

Advanced modulation formats combined with digital signal processing and direct detection is a promising way to realize high capacity, low cost and power efficient short reach optical transmission system. In this paper, we present a detailed investigation on the performance of three advanced modulation formats for 100 Gb/s short reach transmission system. They are PAM-4, CAP-16 and DMT. The detailed digital signal processing required for each modulation format is presented. Comprehensive simulations are carried out to evaluate the performance of each modulation format in terms of received optical power, transmitter bandwidth, relative intensity noise and thermal noise. The performance of each modulation format is also experimentally studied. To the best of our knowledge, we report the first demonstration of a 112 Gb/s transmission over 10km of SSMF employing single band CAP-16 with EML. Finally, a comparison of computational complexity of DSP for the three formats is presented.

BAE Systems' 17μm LWIR camera core for civil, commercial, and military applications

NASA Astrophysics Data System (ADS)

Lee, Jeffrey; Rodriguez, Christian; Blackwell, Richard

2013-06-01

Seventeen (17) µm pixel Long Wave Infrared (LWIR) Sensors based on vanadium oxide (VOx) micro-bolometers have been in full rate production at BAE Systems' Night Vision Sensors facility in Lexington, MA for the past five years.[1] We introduce here a commercial camera core product, the Airia-MTM imaging module, in a VGA format that reads out in 30 and 60Hz progressive modes. The camera core is architected to conserve power with all digital interfaces from the readout integrated circuit through video output. The architecture enables a variety of input/output interfaces including Camera Link, USB 2.0, micro-display drivers and optional RS-170 analog output supporting legacy systems. The modular board architecture of the electronics facilitates hardware upgrades allow us to capitalize on the latest high performance low power electronics developed for the mobile phones. Software and firmware is field upgradeable through a USB 2.0 port. The USB port also gives users access to up to 100 digitally stored (lossless) images.

Blocker-tolerant and high-sensitivity $Δ$$\\!$$Σ$ correlation digitizer for radar and coherent receiver applications

DOE PAGES

Mincey, John S.; Silva-Martinez, Jose; Karsilayan, AydinIlker; ...

2017-03-17

In this study, a coherent subsampling digitizer for pulsed Doppler radar systems is proposed. Prior to transmission, the radar system modulates the RF pulse with a known pseudorandom binary phase shift keying (BPSK) sequence. Upon reception, the radar digitizer uses a programmable sample-and-hold circuit to multiply the received waveform by a properly time-delayed version of the known a priori BPSK sequence. This operation demodulates the desired echo signal while suppressing the spectrum of all in-band noncorrelated interferers, making them appear as noise in the frequency domain. The resulting demodulated narrowband Doppler waveform is then subsampled at the IF frequency bymore » a delta-sigma modulator. Because the digitization bandwidth within the delta-sigma feedback loop is much less than the input bandwidth to the digitizer, the thermal noise outside of the Doppler bandwidth is effectively filtered prior to quantization, providing an increase in signal-to-noise ratio (SNR) at the digitizer's output compared with the input SNR. In this demonstration, a delta-sigma correlation digitizer is fabricated in a 0.18-μm CMOS technology. The digitizer has a power consumption of 1.12 mW with an IIP3 of 7.5 dBm. The digitizer is able to recover Doppler tones in the presence of blockers up to 40 dBm greater than the Doppler tone.« less

Instrumentation System Diagnoses a Thermocouple

NASA Technical Reports Server (NTRS)

Perotti, Jose; Santiago, Josephine; Mata, Carlos; Vokrot, Peter; Zavala, Carlos; Burns, Bradley

2008-01-01

An improved self-validating thermocouple (SVT) instrumentation system not only acquires readings from a thermocouple but is also capable of detecting deterioration and a variety of discrete faults in the thermocouple and its lead wires. Prime examples of detectable discrete faults and deterioration include open- and short-circuit conditions and debonding of the thermocouple junction from the object, the temperature of which one seeks to measure. Debonding is the most common cause of errors in thermocouple measurements, but most prior SVT instrumentation systems have not been capable of detecting debonding. The improved SVT instrumentation system includes power circuitry, a cold-junction compensator, signal-conditioning circuitry, pulse-width-modulation (PWM) thermocouple-excitation circuitry, an analog-to-digital converter (ADC), a digital data processor, and a universal serial bus (USB) interface. The system can operate in any of the following three modes: temperature measurement, thermocouple validation, and bonding/debonding detection. The software running in the processor includes components that implement statistical algorithms to evaluate the state of the thermocouple and the instrumentation system. When the power is first turned on, the user can elect to start a diagnosis/ monitoring sequence, in which the PWM is used to estimate the characteristic times corresponding to the correct configuration. The user also has the option of using previous diagnostic values, which are stored in an electrically erasable, programmable read-only memory so that they are available every time the power is turned on.

Improving the delivery of care and reducing healthcare costs with the digitization of information.

PubMed

Noffsinger, R; Chin, S

2000-01-01

In the coming years, the digitization of information and the Internet will be extremely powerful in reducing healthcare costs while assisting providers in the delivery of care. One example of healthcare inefficiency that can be managed through information digitization is the process of prescription writing. Due to the handwritten and verbal communication surrounding prescription writing, as well as the multiple tiers of authorizations, the prescription drug process causes extensive financial waste as well as medical errors, lost time, and even fatal accidents. Electronic prescription management systems are being designed to address these inefficiencies. By utilizing new electronic prescription systems, physicians not only prescribe more accurately, but also improve formulary compliance thereby reducing pharmacy utilization. These systems expand patient care by presenting proactive alternatives at the point of prescription while reducing costs and providing additional benefits for consumers and healthcare providers.

Distributed Timing and Localization (DiGiTaL)

NASA Technical Reports Server (NTRS)

D'Amico, Simone; Hunter, Roger C.; Baker, Christopher

2017-01-01

The Distributed Timing and Localization (DiGiTaL) system provides nano satellite formations with unprecedented,centimeter-level navigation accuracy in real time and nanosecond-level time synchronization. This is achieved through the integration of a multi-constellation Global Navigation Satellite System (GNSS) receiver, a Chip-Scale Atomic Clock (CSAC), and a dedicated Inter-Satellite Link (ISL). In comparison, traditional single spacecraft GNSS navigation solutions are accurate only to the meter-level due to the sole usage of coarse pseudo-range measurements. To meet the strict requirements of future miniaturized distributed space systems, DiGiTaL uses powerful error-cancelling combinations of raw carrier-phase measurements which are exchanged between the swarming nano satellites through a decentralized network. A reduced-dynamics estimation architecture on board each individual nano satellite processes the resulting millimeter-level noise measurements to reconstruct the fullformation state with high accuracy.

Development of a digital solar simulator based on full-bridge converter

NASA Astrophysics Data System (ADS)

Liu, Chen; Feng, Jian; Liu, Zhilong; Tong, Weichao; Ji, Yibo

2014-02-01

With the development of solar photovoltaic, distribution schemes utilized in power grid had been commonly application, and photovoltaic (PV) inverter is an essential equipment in grid. In this paper, a digital solar simulator based on full-bridge structure is presented. The output characteristic curve of system is electrically similar to silicon solar cells, which can greatly simplify research methods of PV inverter, improve the efficiency of research and development. The proposed simulator consists on a main control board based on TM320F28335, phase-shifted zero-voltage-switching (ZVS) DC-DC full-bridge converter and voltage and current sampling circuit, that allows emulating the voltage-current curve with the open-circuit voltage (Voc) of 900V and the short-circuit current (Isc) of 18A .When the system connected to a PV inverter, the inverter can quickly track from the open-circuit to the maximum power point and keep stability.

An Educational Laboratory for Digital Control and Rapid Prototyping of Power Electronic Circuits

ERIC Educational Resources Information Center

Choi, Sanghun; Saeedifard, M.

2012-01-01

This paper describes a new educational power electronics laboratory that was developed primarily to reinforce experimentally the fundamental concepts presented in a power electronics course. The developed laboratory combines theoretical design, simulation studies, digital control, fabrication, and verification of power-electronic circuits based on…

47 CFR 74.789 - Broadcast regulations applicable to digital low power television and television translator stations.

Code of Federal Regulations, 2010 CFR

2010-10-01

... power television and television translator stations. 74.789 Section 74.789 Telecommunication FEDERAL... AND OTHER PROGRAM DISTRIBUTIONAL SERVICES Low Power TV, TV Translator, and TV Booster Stations § 74.789 Broadcast regulations applicable to digital low power television and television translator...

A digitally assisted, signal folding neural recording amplifier.

PubMed

Chen, Yi; Basu, Arindam; Liu, Lei; Zou, Xiaodan; Rajkumar, Ramamoorthy; Dawe, Gavin Stewart; Je, Minkyu

2014-08-01

A novel signal folding and reconstruction scheme for neural recording applications that exploits the 1/f(n) characteristics of neural signals is described in this paper. The amplified output is 'folded' into a predefined range of voltages by using comparison and reset circuits along with the core amplifier. After this output signal is digitized and transmitted, a reconstruction algorithm can be applied in the digital domain to recover the amplified signal from the folded waveform. This scheme enables the use of an analog-to-digital convertor with less number of bits for the same effective dynamic range. It also reduces the transmission data rate of the recording chip. Both of these features allow power and area savings at the system level. Other advantages of the proposed topology are increased reliability due to the removal of pseudo-resistors, lower harmonic distortion and low-voltage operation. An analysis of the reconstruction error introduced by this scheme is presented along with a behavioral model to provide a quick estimate of the post reconstruction dynamic range. Measurement results from two different core amplifier designs in 65 nm and 180 nm CMOS processes are presented to prove the generality of the proposed scheme in the neural recording applications. Operating from a 1 V power supply, the amplifier in 180 nm CMOS has a gain of 54.2 dB, bandwidth of 5.7 kHz, input referred noise of 3.8 μVrms and power dissipation of 2.52 μW leading to a NEF of 3.1 in spike band. It exhibits a dynamic range of 66 dB and maximum SNDR of 43 dB in LFP band. It also reduces system level power (by reducing the number of bits in the ADC by 2) as well as data rate to 80% of a conventional design. In vivo measurements validate the ability of this amplifier to simultaneously record spike and LFP signals.

Digital photography for the light microscope: results with a gated, video-rate CCD camera and NIH-image software.

PubMed

Shaw, S L; Salmon, E D; Quatrano, R S

1995-12-01

In this report, we describe a relatively inexpensive method for acquiring, storing and processing light microscope images that combines the advantages of video technology with the powerful medium now termed digital photography. Digital photography refers to the recording of images as digital files that are stored, manipulated and displayed using a computer. This report details the use of a gated video-rate charge-coupled device (CCD) camera and a frame grabber board for capturing 256 gray-level digital images from the light microscope. This camera gives high-resolution bright-field, phase contrast and differential interference contrast (DIC) images but, also, with gated on-chip integration, has the capability to record low-light level fluorescent images. The basic components of the digital photography system are described, and examples are presented of fluorescence and bright-field micrographs. Digital processing of images to remove noise, to enhance contrast and to prepare figures for printing is discussed.

An easy-to-operate portable pulse-height analysis system for area monitoring with TEPC in radiation protection

NASA Astrophysics Data System (ADS)

Kunz, A.; Pihet, P.; Arend, E.; Menzel, H. G.

1990-12-01

A portable area monitor for the measurement of dose-equivalent quantities in practical radiation-protection work has been developed. The detector applied is a low-pressure proportional counter (TEPC) used in microdosimetry. The complex analysis system required has been optimized with regard to low power consumption and small size to achieve a real operational survey meter. The newly designed electronic includes complete analog, digital and microprocessor boards. It presents the characteristic of fast pulse-height processing over a large (5 decades) dynamic range. Three original circuits have been specifically developed, consisting of: (1) a miniaturized adjustable high-voltage power supply with low ripple and high stability; (2) a double spectroscopy amplifier with constant gain ratio and common pole-zero stage; and (3) an analog-to-digital converter with quasi-logarithmic characteristics based on a flash converter using fast comparators associated in parallel. With the incorporated single-board computer, the maximal total power consumption is 5 W, enabling 40 hours operation time with batteries. With minor adaptations the equipment is proposed as a low-cost solution for various measuring problems in environmental studies.

Identification of Modeling Approaches To Support Common-Cause Failure Analysis

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

Korsah, Kofi; Wood, Richard Thomas

2015-06-01

Experience with applying current guidance and practices for common-cause failure (CCF) mitigation to digital instrumentation and control (I&C) systems has proven problematic, and the regulatory environment has been unpredictable. The impact of CCF vulnerability is to inhibit I&C modernization and, thereby, challenge the long-term sustainability of existing plants. For new plants and advanced reactor concepts, the issue of CCF vulnerability for highly integrated digital I&C systems imposes a design burden resulting in higher costs and increased complexity. The regulatory uncertainty regarding which mitigation strategies are acceptable (e.g., what diversity is needed and how much is sufficient) drives designers to adoptmore » complicated, costly solutions devised for existing plants. The conditions that constrain the transition to digital I&C technology by the U.S. nuclear industry require crosscutting research to resolve uncertainty, demonstrate necessary characteristics, and establish an objective basis for qualification of digital technology for usage in Nuclear Power Plant (NPP) I&C applications. To fulfill this research need, Oak Ridge National Laboratory is conducting an investigation into mitigation of CCF vulnerability for nuclear-qualified applications. The outcome of this research is expected to contribute to a fundamentally sound, comprehensive technical basis for establishing the qualification of digital technology for nuclear power applications. This report documents the investigation of modeling approaches for representing failure of I&C systems. Failure models are used when there is a need to analyze how the probability of success (or failure) of a system depends on the success (or failure) of individual elements. If these failure models are extensible to represent CCF, then they can be employed to support analysis of CCF vulnerabilities and mitigation strategies. Specifically, the research findings documented in this report identify modeling approaches that can be adapted to contribute to the basis for developing systematic methods, quantifiable measures, and objective criteria for evaluating CCF vulnerabilities and mitigation strategies.« less

Adaptive digital beamforming for a CDMA mobile communications payload

NASA Technical Reports Server (NTRS)

Munoz-Garcia, Samuel G.; Ruiz, Javier Benedicto

1993-01-01

In recent years, Spread-Spectrum Code Division Multiple Access (CDMA) has become a very popular access scheme for mobile communications due to a variety of reasons: excellent performance in multipath environments, high scope for frequency reuse, graceful degradation near saturation, etc. In this way, a CDMA system can support simultaneous digital communication among a large community of relatively uncoordinated users sharing a given frequency band. Nevertheless, there are also important problems associated with the use of CDMA. First, in a conventional CDMA scheme, the signature sequences of asynchronous users are not orthogonal and, as the number of active users increases, the self-noise generated by the mutual interference between users considerably degrades the performance, particularly in the return link. Furthermore, when there is a large disparity in received powers - due to differences in slant range or atmospheric attenuation - the non-zero cross-correlation between the signals gives rise to the so-called near-far problem. This leads to an inefficient utilization of the satellite resources and, consequently, to a drastic reduction in capacity. Several techniques were proposed to overcome this problem, such as Synchronized CDMA - in which the signature sequences of the different users are quasi-orthogonal - and power control. At the expense of increased network complexity and user coordination, these techniques enable the system capacity to be restored by equitably sharing the satellite resources among the users. An alternative solution is presented based upon the use of time-reference adaptive digital beamforming on board the satellite. This technique enables a high number of independently steered beams to be generated from a single phased array antenna, which automatically track the desired user signal and null the unwanted interference source. In order to use a time-reference adaptive antenna in a communications system, the main challenge is to obtain a reference signal highly correlated with the desired user signal and uncorrelated with the interferences. CDMA lends itself very easily to the generation of such a reference signal, thanks to the a priori knowledge of the user's signature sequence. First, the integration of an adaptive antenna in an asynchronous CDMA system is analyzed. The adaptive antenna system can provide increased interference rejection - much higher than that afforded by the code alone - and, since CDMA is mainly interference limited, any reduction in interference converts directly and linearly into an increase in capacity. Analyses and computer simulations are presented that show how an asynchronous CDMA system incorporating adaptive beamforming can provide at least as much capacity as a synchronous system. More importantly, the proposed concept allows the near-far effect to be mitigated without requiring a tight coordination of the users in terms of transmitted power control or network synchronization. The system is extremely robust to the near-far effect because the signals reaching the satellite from directions other than that of the desired user - which are likely to have different power levels - are adaptively canceled by the antenna. Finally, a payload architecture is presented that illustrates the practical implementation of this concept. This digital payload architecture demonstrates that with the advent of high performance CMOS digital processing, the on-board implementation of complex DSP techniques - in particular Digital Beamforming - has become possible, being most attractive for Mobile Satellite Communications.

Adaptive digital beamforming for a CDMA mobile communications payload

NASA Astrophysics Data System (ADS)

Munoz-Garcia, Samuel G.; Ruiz, Javier Benedicto

In recent years, Spread-Spectrum Code Division Multiple Access (CDMA) has become a very popular access scheme for mobile communications due to a variety of reasons: excellent performance in multipath environments, high scope for frequency reuse, graceful degradation near saturation, etc. In this way, a CDMA system can support simultaneous digital communication among a large community of relatively uncoordinated users sharing a given frequency band. Nevertheless, there are also important problems associated with the use of CDMA. First, in a conventional CDMA scheme, the signature sequences of asynchronous users are not orthogonal and, as the number of active users increases, the self-noise generated by the mutual interference between users considerably degrades the performance, particularly in the return link. Furthermore, when there is a large disparity in received powers - due to differences in slant range or atmospheric attenuation - the non-zero cross-correlation between the signals gives rise to the so-called near-far problem. This leads to an inefficient utilization of the satellite resources and, consequently, to a drastic reduction in capacity. Several techniques were proposed to overcome this problem, such as Synchronized CDMA - in which the signature sequences of the different users are quasi-orthogonal - and power control. At the expense of increased network complexity and user coordination, these techniques enable the system capacity to be restored by equitably sharing the satellite resources among the users. An alternative solution is presented based upon the use of time-reference adaptive digital beamforming on board the satellite. This technique enables a high number of independently steered beams to be generated from a single phased array antenna, which automatically track the desired user signal and null the unwanted interference source. In order to use a time-reference adaptive antenna in a communications system, the main challenge is to obtain a reference signal highly correlated with the desired user signal and uncorrelated with the interferences. CDMA lends itself very easily to the generation of such a reference signal, thanks to the a priori knowledge of the user's signature sequence. First, the integration of an adaptive antenna in an asynchronous CDMA system is analyzed. The adaptive antenna system can provide increased interference rejection - much higher than that afforded by the code alone - and, since CDMA is mainly interference limited, any reduction in interference converts directly and linearly into an increase in capacity. Analyses and computer simulations are presented that show how an asynchronous CDMA system incorporating adaptive beamforming can provide at least as much capacity as a synchronous system. More importantly, the proposed concept allows the near-far effect to be mitigated without requiring a tight coordination of the users in terms of transmitted power control or network synchronization. The system is extremely robust to the near-far effect because the signals reaching the satellite from directions other than that of the desired user - which are likely to have different power levels - are adaptively canceled by the antenna. Finally, a payload architecture is presented that illustrates the practical implementation of this concept.

High-resolution streaming video integrated with UGS systems

NASA Astrophysics Data System (ADS)

Rohrer, Matthew

2010-04-01

Imagery has proven to be a valuable complement to Unattended Ground Sensor (UGS) systems. It provides ultimate verification of the nature of detected targets. However, due to the power, bandwidth, and technological limitations inherent to UGS, sacrifices have been made to the imagery portion of such systems. The result is that these systems produce lower resolution images in small quantities. Currently, a high resolution, wireless imaging system is being developed to bring megapixel, streaming video to remote locations to operate in concert with UGS. This paper will provide an overview of how using Wifi radios, new image based Digital Signal Processors (DSP) running advanced target detection algorithms, and high resolution cameras gives the user an opportunity to take high-powered video imagers to areas where power conservation is a necessity.

POWER SUPPLY CONTROL AND MONITORING FOR THE SNS RING AND TRANSPORT SYSTEM

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

LAMBIASE,R.; OERTER,B.; PENG,S.

2001-06-28

There are approximately 300 magnet power supplies in the SNS accumulator ring and transport lines. Control and monitoring of the these converters will be primarily accomplished with a new Power Supply Interface and Controller (PSI/PSC) system developed for the SNS project. This PSI/PSC system provides all analog and digital commands and status readbacks in one fiber isolated module. With a maximum rate of 10KHz, the PSI/PSC must be supplemented with higher speed systems for the wide bandwidth pulsed injection supplies, and the even wider bandwidth extraction kickers. This paper describes the implementation of this PSI/PSC system, which was developed throughmore » an industry/laboratory collaboration, and the supplementary equipment used to support the wider bandwidth pulsed supplies.« less

Optical modulator system

NASA Technical Reports Server (NTRS)

Brand, J.

1972-01-01

The fabrication, test, and delivery of an optical modulator system which will operate with a mode-locked Nd:YAG laser indicating at either 1.06 or 0.53 micrometers is discussed. The delivered hardware operates at data rates up to 400 Mbps and includes a 0.53 micrometer electrooptic modulator, a 1.06 micrometer electrooptic modulator with power supply and signal processing electronics with power supply. The modulators contain solid state drivers which accept digital signals with MECL logic levels, temperature controllers to maintain a stable thermal environment for the modulator crystals, and automatic electronic compensation to maximize the extinction ratio. The modulators use two lithium tantalate crystals cascaded in a double pass configuration. The signal processing electronics include encoding electronics which are capable of digitizing analog signals between the limit of + or - 0.75 volts at a maximum rate of 80 megasamples per second with 5 bit resolution. The digital samples are serialized and made available as a 400 Mbps serial NRZ data source for the modulators. A pseudorandom (PN) generator is also included in the signal processing electronics. This data source generates PN sequences with lengths between 31 bits and 32,767 bits in a serial NRZ format at rates up to 400 Mbps.

Lunar Pole Illumination and Communications Maps Computed from GSSR Elevation Data

NASA Technical Reports Server (NTRS)

Bryant, Scott

2009-01-01

A Digital Elevation Model of the lunar south pole was produced using Goldstone Solar System RADAR (GSSR) data obtained in 2006.12 This model has 40-meter horizontal resolution and about 5-meter relative vertical accuracy. This Digital Elevation Model was used to compute average solar illumination and Earth visibility with 100 kilometers of the lunar south pole. The elevation data were converted into local terrain horizon masks, then converted into lunar-centric latitude and longitude coordinates. The horizon masks were compared to latitude, longitude regions bounding the maximum Sun and Earth motions relative to the moon. Estimates of Earth visibility were computed by integrating the area of the region bounding the Earth's motion that was below the horizon mask. Solar illumination and other metrics were computed similarly. Proposed lunar south pole base sites were examined in detail, with the best site showing yearly solar power availability of 92 percent and Direct-To-Earth (DTE) communication availability of about 50 percent. Similar analysis of the lunar south pole used an older GSSR Digital Elevation Model with 600-meter horizontal resolution. The paper also explores using a heliostat to reduce the photovoltaic power system mass and complexity.

Digital Portfolios: Powerful Marketing Tool for Communications Students

ERIC Educational Resources Information Center

Nikirk, Martin

2008-01-01

A digital portfolio is a powerful marketing tool for young people searching for employment in the communication or interactive media fields. With a digital portfolio, students can demonstrate their skills at working with software tools, demonstrate appropriate use of materials, explain technical procedures, show an understanding of processes and…

Digital Ink: In-Class Annotation of PowerPoint Lectures

ERIC Educational Resources Information Center

Johnson, Anne E.

2008-01-01

Digital ink is a tool that, in conjunction with Microsoft PowerPoint software, allows real-time freehand annotation of presentations. Annotation of slides during class encourages student engagement with the material and problems under discussion. Digital ink annotation is a technique suitable for teaching across many disciplines, but is especially…

What Is A Picture Archiving And Communication System (PACS)?

NASA Astrophysics Data System (ADS)

Marceau, Carla

1982-01-01

A PACS is a digital system for acquiring, storing, moving and displaying picture or image information. It is an alternative to film jackets that has been made possible by recent breakthroughs in computer technology: telecommunications, local area nets and optical disks. The fundamental concept of the digital representation of image information is introduced. It is shown that freeing images from a material representation on film or paper leads to a dramatic increase in flexibility in our use of the images. The ultimate goal of a medical PACS system is a radiology department without film jackets. The inherent nature of digital images and the power of the computer allow instant free "copies" of images to be made and thrown away. These copies can be transmitted to distant sites in seconds, without the "original" ever leaving the archives of the radiology department. The result is a radiology department with much freer access to patient images and greater protection against lost or misplaced image information. Finally, images in digital form can be treated as data for the computer in image processing, which includes enhancement, reconstruction and even computer-aided analysis.

Cryo Power and Heat Transfer

DTIC Science & Technology

2004-09-01

of DMD ...........................................................................................47 Figure 3.15: Lens used for intensity...51 Figure 3.18: Imaging system for DMD ...temperatures, converts to a ceramic material Digital Micromirror Device ( DMD ) – A MEMS device that consists of tiny mirror used for light modulation

A fast low-power optical memory based on coupled micro-ring lasers

NASA Astrophysics Data System (ADS)

Hill, Martin T.; Dorren, Harmen J. S.; de Vries, Tjibbe; Leijtens, Xaveer J. M.; den Besten, Jan Hendrik; Smalbrugge, Barry; Oei, Yok-Siang; Binsma, Hans; Khoe, Giok-Djan; Smit, Meint K.

2004-11-01

The increasing speed of fibre-optic-based telecommunications has focused attention on high-speed optical processing of digital information. Complex optical processing requires a high-density, high-speed, low-power optical memory that can be integrated with planar semiconductor technology for buffering of decisions and telecommunication data. Recently, ring lasers with extremely small size and low operating power have been made, and we demonstrate here a memory element constructed by interconnecting these microscopic lasers. Our device occupies an area of 18 × 40µm2 on an InP/InGaAsP photonic integrated circuit, and switches within 20ps with 5.5fJ optical switching energy. Simulations show that the element has the potential for much smaller dimensions and switching times. Large numbers of such memory elements can be densely integrated and interconnected on a photonic integrated circuit: fast digital optical information processing systems employing large-scale integration should now be viable.

Dithering Digital Ripple Correlation Control for Photovoltaic Maximum Power Point Tracking

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

Barth, C; Pilawa-Podgurski, RCN

This study demonstrates a new method for rapid and precise maximum power point tracking in photovoltaic (PV) applications using dithered PWM control. Constraints imposed by efficiency, cost, and component size limit the available PWM resolution of a power converter, and may in turn limit the MPP tracking efficiency of the PV system. In these scenarios, PWM dithering can be used to improve average PWM resolution. In this study, we present a control technique that uses ripple correlation control (RCC) on the dithering ripple, thereby achieving simultaneous fast tracking speed and high tracking accuracy. Moreover, the proposed method solves some ofmore » the practical challenges that have to date limited the effectiveness of RCC in solar PV applications. We present a theoretical derivation of the principles behind dithering digital ripple correlation control, as well as experimental results that show excellent tracking speed and accuracy with basic hardware requirements.« less

Ambulatory polysomnography using a new programmable amplifier system with on-line digitization of data: technical and clinical findings.

PubMed

Drewes, A M; Nielsen, K D; Taagholt, S J; Svendsen, L; Bjerregård, K; Nielsson, L; Kristensen, L

1996-05-01

A new system for polysomnographic recording at home is presented. It consists of a 12 to 24-channel amplifier system with direct digitization of the polygraph signals using a portable computer. Sampling frequency, amplification and filter settings can be defined by the user, and the signals are evaluated at bedside. Technical testing proved a high signal/noise ratio, linear amplification and a good signal quality. Clinical testing of the first 100 recordings showed that they were acceptable for conventional sleep scoring in 98 cases. A comparison of two consecutive recordings was done in 9 healthy subjects and 11 patients with rheumatic disorders. Using conventional sleep staging, only a slight "first night effect" (FNE) was demonstrated in the sleep architecture. Power spectral analysis using autoregressive modeling demonstrated only a difference of power between the 2 nights in the beta (14.5-25 Hz) band. In conclusion, the usability and technical advantages make the system very suitable for ambulatory recordings and only a minimal FNE should be considered when results are evaluated.

Integrated Digital Flight Control System for the Space Shuttle Orbiter

NASA Technical Reports Server (NTRS)

1973-01-01

The objectives of the integrated digital flight control system (DFCS) is to provide rotational and translational control of the space shuttle orbiter in all phases of flight: from launch ascent through orbit to entry and touchdown, and during powered horizontal flights. The program provides a versatile control system structure while maintaining uniform communications with other programs, sensors, and control effectors by using an executive routine/functional subroutine format. The program reads all external variables at a single point, copies them into its dedicated storage, and then calls the required subroutines in the proper sequence. As a result, the flight control program is largely independent of other programs in the computer complex and is equally insensitive to characteristics of the processor configuration. The integrated structure is described of the control system and the DFCS executive routine which embodies that structure. The input and output, including jet selection are included. Specific estimation and control algorithm are shown for the various mission phases: cruise (including horizontal powered flight), entry, on-orbit, and boost. Attitude maneuver routines that interface with the DFCS are included.

System and method for regulating resonant inverters

DOEpatents

Stevanovic, Ljubisa Dragoljub [Clifton Park, NY; Zane, Regan Andrew [Superior, CO

2007-08-28

A technique is provided for direct digital phase control of resonant inverters based on sensing of one or more parameters of the resonant inverter. The resonant inverter control system includes a switching circuit for applying power signals to the resonant inverter and a sensor for sensing one or more parameters of the resonant inverter. The one or more parameters are representative of a phase angle. The resonant inverter control system also includes a comparator for comparing the one or more parameters to a reference value and a digital controller for determining timing of the one or more parameters and for regulating operation of the switching circuit based upon the timing of the one or more parameters.

SiC Integrated Circuits for Power Device Drivers Able to Operate in Harsh Environments

NASA Astrophysics Data System (ADS)

Godignon, P.; Alexandru, M.; Banu, V.; Montserrat, J.; Jorda, X.; Vellvehi, M.; Schmidt, B.; Michel, P.; Millan, J.

2014-08-01

The currently developed SiC electronic devices are more robust to high temperature operation and radiation exposure damage than correspondingly rated Si ones. In order to integrate the existent SiC high power and high temperature electronics into more complex systems, a SiC integrated circuit (IC) technology capable of operation at temperatures substantially above the conventional ones is required. Therefore, this paper is a step towards the development of ICs-control electronics that have to attend the harsh environment power applications. Concretely, we present the development of SiC MESFET-based digital circuitry, able to integrate gate driver for SiC power devices. Furthermore, a planar lateral power MESFET is developed with the aim of its co-integration on the same chip with the previously mentioned SiC digital ICs technology. And finally, experimental results on SiC Schottky-gated devices irradiated with protons and electrons are presented. This development is based on the Tungsten-Schottky interface technology used for the fabrication of stable SiC Schottky diodes for the European Space Agency Mission BepiColombo.

Monitoring of electric-cardio signals based on DSP

NASA Astrophysics Data System (ADS)

Yan, Yi-xin; Sun, Hui-nan; Lv, Shuang

2008-10-01

Monitoring of electric-cardio signals is the most direct method of discovering heart diseases. This article presents an electric-cardio signal acquisition and processing system based on DSP. According to the features of electric-cardio signals, the proposed system uses the AgCl electrode as electric-cardio signals sensor, and acquires analog signals with AD620 as the prepositional amplifier, and the digital system equipped is with TMS320LF2407A DSP. The design of digital filter and the analysis of heart rate variation are realized by programming in the DSP. Finally the ECG is obtained with P and T waves along with obvious QRS multi-wave characteristics. The system has low power dissipation, low cost and high precision, which meets the requirements for medical instruments.

Mobile measurement setup according to IEC 62220-1-2 for DQE determination on digital mammography systems

NASA Astrophysics Data System (ADS)

Greiter, Matthias B.; Hoeschen, Christoph

2010-04-01

The international standard IEC 62220-1-2 defines the measurement procedure for determination of the detective quantum efficiency (DQE) of digital x-ray imaging devices used in mammography. A mobile setup complying to this standard and adaptable to most current systems was constructed in the Helmholtz Zentrum München to allow for an objective technical comparison of current full field digital mammography units employed in mammography screening in Germany. This article demonstrates the setup's capabilities with a focus on the measurement uncertainties of all quantities contributing to DQE measurements. Evaluation of uncertainties encompasses results from measurements on a Sectra Microdose Mammography in clinical use, as well as on a prototype of a Fujifilm Amulet system at various radiation qualities. Both systems have a high spatial resolution of 50 μm × 50 μm. The modulation transfer function (MTF), noise power spectrum (NPS) and DQE of the Sectra MDM are presented in comparison to results previously published by other authors.

Cost-effective bidirectional digitized radio-over-fiber systems employing sigma delta modulation

NASA Astrophysics Data System (ADS)

Lee, Kyung Woon; Jung, HyunDo; Park, Jung Ho

2016-11-01

We propose a cost effective digitized radio-over-fiber (D-RoF) system employing a sigma delta modulation (SDM) and a bidirectional transmission technique using phase modulated downlink and intensity modulated uplink. SDM is transparent to different radio access technologies and modulation formats, and more suitable for a downlink of wireless system because a digital to analog converter (DAC) can be avoided at the base station (BS). Also, Central station and BS share the same light source by using a phase modulation for the downlink and an intensity modulation for the uplink transmission. Avoiding DACs and light sources have advantages in terms of cost reduction, power consumption, and compatibility with conventional wireless network structure. We have designed a cost effective bidirectional D-RoF system using a low pass SDM and measured the downlink and uplink transmission performance in terms of error vector magnitude, signal spectra, and constellations, which are based on the 10MHz LTE 64-QAM standard.

Low cost high efficiency GaAs monolithic RF module for SARSAT distress beacons

NASA Technical Reports Server (NTRS)

Petersen, W. C.; Siu, D. P.; Cook, H. F.

1991-01-01

Low cost high performance (5 Watts output) 406 MHz beacons are urgently needed to realize the maximum utilization of the Search and Rescue Satellite-Aided Tracking (SARSAT) system spearheaded in the U.S. by NASA. Although current technology can produce beacons meeting the output power requirement, power consumption is high due to the low efficiency of available transmitters. Field performance is currently unsatisfactory due to the lack of safe and reliable high density batteries capable of operation at -40 C. Low cost production is also a crucial but elusive requirement for the ultimate wide scale utilization of this system. Microwave Monolithics Incorporated (MMInc.) has proposed to make both the technical and cost goals for the SARSAT beacon attainable by developing a monolithic GaAs chip set for the RF module. This chip set consists of a high efficiency power amplifier and a bi-phase modulator. In addition to implementing the RF module in Monolithic Microwave Integrated Circuit (MMIC) form to minimize ultimate production costs, the power amplifier has a power-added efficiency nearly twice that attained with current commercial technology. A distress beacon built using this RF module chip set will be significantly smaller in size and lighter in weight due to a smaller battery requirement, since the 406 MHz signal source and the digital controller have far lower power consumption compared to the 5 watt power amplifier. All the program tasks have been successfully completed. The GaAs MMIC RF module chip set has been designed to be compatible with the present 406 MHz signal source and digital controller. A complete high performance low cost SARSAT beacon can be realized with only additional minor iteration and systems integration.

A low-noise low-power EEG acquisition node for scalable brain-machine interfaces

NASA Astrophysics Data System (ADS)

Sullivan, Thomas J.; Deiss, Stephen R.; Cauwenberghs, Gert; Jung, Tzyy-Ping

2007-05-01

Electroencephalograph (EEG) recording systems offer a versatile, noninvasive window on the brain's spatio-temporal activity for many neuroscience and clinical applications. Our research aims at improving the spatial resolution and mobility of EEG recording by reducing the form factor, power drain and signal fanout of the EEG acquisition node in a scalable sensor array architecture. We present such a node integrated onto a dimesized circuit board that contains a sensor's complete signal processing front-end, including amplifier, filters, and analog-to-digital conversion. A daisy-chain configuration between boards with bit-serial output reduces the wiring needed. The circuit's low power consumption of 423 μW supports EEG systems with hundreds of electrodes to operate from small batteries for many hours. Coupling between the bit-serial output and the highly sensitive analog input due to dense integration of analog and digital functions on the circuit board results in a deterministic noise component in the output, larger than the intrinsic sensor and circuit noise. With software correction of this noise contribution, the system achieves an input-referred noise of 0.277 μVrms in the signal band of 1 to 100 Hz, comparable to the best medical-grade systems in use. A chain of seven nodes using EEG dry electrodes created in micro-electrical-mechanical system (MEMS) technology is demonstrated in a real-world setting.

University of Washington Mobile Planetarium: Bringing HST Science to Seattle Public Schools

NASA Astrophysics Data System (ADS)

Gailey, Justin; Fraiser, O.; Rosenfield, P.; Byler, E.; Wisniewski, J. P.

2013-01-01

Digital planetariums are becoming mainstays of astronomy education as projection technology prices fall and planetarium software becomes more powerful and more freely available. In 2010, the University of Washington upgraded their star-ball projector to a digital system that is powered by Microsoft Research’s WorldWide Telescope. To increase the number of underserved elementary and high school students the UW Astronomy department reaches, we obtained an HST education and public outreach grant to create lesson content, offset transportation costs to visit the UW planetarium for Seattle Public School students, and purchase a mobile planetarium to bring to public schools. We present a pilot program to test and evaluate the efficacy of the mobile planetarium in a high school setting.

Goldstone R/D High Speed Data Acquisition System

NASA Technical Reports Server (NTRS)

Deutsch, L. J.; Jurgens, R. F.; Brokl, S. S.

1984-01-01

A digital data acquisition system that meets the requirements of several users (initially the planetary radar program) is planned for general use at Deep Space Station 14 (DSS 14). The system, now partially complete, is controlled by VAX 11/780 computer that is programmed in high level languages. A DEC Data Controller is included for moderate-speed data acquisition, low speed data display, and for a digital interface to special user-provided devices. The high-speed data acquisition is performed in devices that are being designed and built at JPL. Analog IF signals are converted to a digitized 50 MHz real signal. This signal is filtered and mixed digitally to baseband after which its phase code (a PN sequence in the case of planetary radar) is removed. It may then be accumulated (or averaged) and fed into the VAX through an FPS 5210 array processor. Further data processing before entering the VAX is thus possible (computation and accumulation of the power spectra, for example). The system is to be located in the research and development pedestal at DSS 14 for easy access by researchers in radio astronomy as well as telemetry processing and antenna arraying.

Dagik Earth: A Digital Globe Project for Classrooms, Science Museums, and Research Institutes

NASA Astrophysics Data System (ADS)

Saito, A.; Tsugawa, T.

2017-12-01

Digital globe system is a powerful tool to make the audiences understand phenomena on the Earth and planets in intuitive way. Geo-cosmos of Miraikan, Japan uses 6-m spherical LED, and is one of the largest systems of digital globe. Science on a Sphere (SOS) by NOAA is a digital globe system that is most widely used in science museums around the world. These systems are so expensive that the usage of the digital globes is mainly limited to large-scale science museums. Dagik Earth is a digital globe project that promotes educational programs using digital globe with low cost. It aims to be used especially in classrooms. The cost for the digital globe of Dagik Earth is from several US dollars if PC and PC projector are available. It uses white spheres, such as balloons and balance balls, as the screen. The software is provided by the project with free of charge for the educational usage. The software runs on devices of Windows, Mac and iOS. There are English and Chinese language versions of the PC software besides Japanese version. The number of the registered users of Dagik Earth is about 1,400 in Japan. About 60% of them belongs to schools, 30% to universities and research institutes, and 8% to science museums. In schools, it is used in classes by teachers, and science activities by students. Several teachers have used the system for five years and more. In a students' activity, Dagik Earth contents on the typhoon, solar eclipse, and satellite launch were created and presented in a school festival. This is a good example of the usage of Dagik Earth for STEM education. In the presentation, the system and activity of Dagik Earth will be presented, and the future expansion of the project will be discussed.

Specification for procurement of water-level sensing instrumentation, specification number HIF-I-1

USGS Publications Warehouse

Rapp, D.H.

1982-01-01

This specification is to communicate to instrument manufacturers the U.S. Geological Survey 's requirements. It covers systems for sensing the elevation of the water surface on open channels, rivers, lakes, reservoirs, storm-sewer pipes, and observation wells at Survey data-collection sites. The signal output (mechanical or electrical) must meet the signal input requirements of analog to digital and digital input recorders in use by the Survey. A classification of stage-sensing systems by common characteristics is used to aid Survey people making system selections. These characteristics are (1) system type (contact or noncontact), (2) sensor type and sensing distance, (3) accuracy, (4) range, (5) power requirements, (6) system size and weight, and (7) data output signal. Acceptable system requirements cover system configurations, signal outputs, materials, operation manuals, detailed environmental conditions, calibration procedures, system accuracy, power requirements, installation limitations, maintainability, safety, and workmanship. An outline of the qualification test procedures and failure criteria are also given. The Hydrologic Instrumentation Facility at NSTL Station, Mississippi will test available systems to determine if they meet the specification in this report for inclusion in the Survey 's 'Qualified Products List'. This list will be used for future procurement of water-level sensing systems by the Survey. (USGS)

A Fully Integrated Sensor SoC with Digital Calibration Hardware and Wireless Transceiver at 2.4 GHz

PubMed Central

Kim, Dong-Sun; Jang, Sung-Joon; Hwang, Tae-Ho

2013-01-01

A single-chip sensor system-on-a-chip (SoC) that implements radio for 2.4 GHz, complete digital baseband physical layer (PHY), 10-bit sigma-delta analog-to-digital converter and dedicated sensor calibration hardware for industrial sensing systems has been proposed and integrated in a 0.18-μm CMOS technology. The transceiver's building block includes a low-noise amplifier, mixer, channel filter, receiver signal-strength indicator, frequency synthesizer, voltage-controlled oscillator, and power amplifier. In addition, the digital building block consists of offset quadrature phase-shift keying (OQPSK) modulation, demodulation, carrier frequency offset compensation, auto-gain control, digital MAC function, sensor calibration hardware and embedded 8-bit microcontroller. The digital MAC function supports cyclic redundancy check (CRC), inter-symbol timing check, MAC frame control, and automatic retransmission. The embedded sensor signal processing block consists of calibration coefficient calculator, sensing data calibration mapper and sigma-delta analog-to-digital converter with digital decimation filter. The sensitivity of the overall receiver and the error vector magnitude (EVM) of the overall transmitter are −99 dBm and 18.14%, respectively. The proposed calibration scheme has a reduction of errors by about 45.4% compared with the improved progressive polynomial calibration (PPC) method and the maximum current consumption of the SoC is 16 mA. PMID:23698271

Digitisation of Scenic and Historic Interest Areas in China

NASA Astrophysics Data System (ADS)

Yang, C.; Lawson, G.; Sim, J.

2015-08-01

Digital documents have become the major information source for heritage conservation practice. More heritage managers today use electronic maps and digital information systems to facilitate management and conservation of cultural heritage. However, the social aspects of digital heritage have not been sufficiently recognised. The aim of this paper is to examine China's `Digital Scenic Area' project, a national program started in 2004, to reveal the political and economic powers behind digital heritage practice. It was found that this project was only conducted within the most popular tourist destinations in China. Tourism information was the main object but information about landscape cultures were neglected in this project. This project also demonstrated that digital management was more like a political or economic symbol rather than a tool for heritage conservation. However, using digital technologies are still considered by the local government as a highly objective way of heritage management. Selected as a typical Scenic Area in China, Slender West Lake in Yangzhou was investigated to identify heritage stakeholder's attitudes toward digital management and the request from local management practice.

Human System Simulation in Support of Human Performance Technical Basis at NPPs

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

David Gertman; Katya Le Blanc; alan mecham

2010-06-01

This paper focuses on strategies and progress toward establishing the Idaho National Laboratory’s (INL’s) Human Systems Simulator Laboratory at the Center for Advanced Energy Studies (CAES), a consortium of Idaho State Universities. The INL is one of the National Laboratories of the US Department of Energy. One of the first planned applications for the Human Systems Simulator Laboratory is implementation of a dynamic nuclear power plant simulation (NPP) where studies of operator workload, situation awareness, performance and preference will be carried out in simulated control rooms including nuclear power plant control rooms. Simulation offers a means by which to reviewmore » operational concepts, improve design practices and provide a technical basis for licensing decisions. In preparation for the next generation power plant and current government and industry efforts in support of light water reactor sustainability, human operators will be attached to a suite of physiological measurement instruments and, in combination with traditional Human Factors Measurement techniques, carry out control room tasks in simulated advanced digital and hybrid analog/digital control rooms. The current focus of the Human Systems Simulator Laboratory is building core competence in quantitative and qualitative measurements of situation awareness and workload. Of particular interest is whether introduction of digital systems including automated procedures has the potential to reduce workload and enhance safety while improving situation awareness or whether workload is merely shifted and situation awareness is modified in yet to be determined ways. Data analysis is carried out by engineers and scientists and includes measures of the physical and neurological correlates of human performance. The current approach supports a user-centered design philosophy (see ISO 13407 “Human Centered Design Process for Interactive Systems, 1999) wherein the context for task performance along with the requirements of the end-user are taken into account during the design process and the validity of design is determined through testing of real end users« less

A 128K-bit CCD buffer memory system

NASA Technical Reports Server (NTRS)

Siemens, K. H.; Wallace, R. W.; Robinson, C. R.

1976-01-01

A prototype system was implemented to demonstrate that CCD's can be applied advantageously to the problem of low power digital storage and particularly to the problem of interfacing widely varying data rates. 8K-bit CCD shift register memories were used to construct a feasibility model 128K-bit buffer memory system. Peak power dissipation during a data transfer is less than 7 W., while idle power is approximately 5.4 W. The system features automatic data input synchronization with the recirculating CCD memory block start address. Descriptions are provided of both the buffer memory system and a custom tester that was used to exercise the memory. The testing procedures and testing results are discussed. Suggestions are provided for further development with regards to the utilization of advanced versions of CCD memory devices to both simplified and expanded memory system applications.

Cost-estimating for commercial digital printing

NASA Astrophysics Data System (ADS)

Keif, Malcolm G.

2007-01-01

The purpose of this study is to document current cost-estimating practices used in commercial digital printing. A research study was conducted to determine the use of cost-estimating in commercial digital printing companies. This study answers the questions: 1) What methods are currently being used to estimate digital printing? 2) What is the relationship between estimating and pricing digital printing? 3) To what extent, if at all, do digital printers use full-absorption, all-inclusive hourly rates for estimating? Three different digital printing models were identified: 1) Traditional print providers, who supplement their offset presswork with digital printing for short-run color and versioned commercial print; 2) "Low-touch" print providers, who leverage the power of the Internet to streamline business transactions with digital storefronts; 3) Marketing solutions providers, who see printing less as a discrete manufacturing process and more as a component of a complete marketing campaign. Each model approaches estimating differently. Understanding and predicting costs can be extremely beneficial. Establishing a reliable system to estimate those costs can be somewhat challenging though. Unquestionably, cost-estimating digital printing will increase in relevance in the years ahead, as margins tighten and cost knowledge becomes increasingly more critical.

A real-time control system for the control of suspended interferometers based on hybrid computing techniques

NASA Astrophysics Data System (ADS)

Acernese, Fausto; Barone, Fabrizio; De Rosa, Rosario; Eleuteri, Antonio; Milano, Leopoldo; Pardi, Silvio; Ricciardi, Iolanda; Russo, Guido

2004-09-01

One of the main requirements of a digital system for the control of interferometric detectors of gravitational waves is the computing power, that is a direct consequence of the increasing complexity of the digital algorithms necessary for the control signals generation. For this specific task many specialized non standard real-time architectures have been developed, often very expensive and difficult to upgrade. On the other hand, such computing power is generally fully available for off-line applications on standard Pc based systems. Therefore, a possible and obvious solution may be provided by the integration of both the real-time and off-line architecture resulting in a hybrid control system architecture based on standards available components, trying to get both the advantages of the perfect data synchronization provided by the real-time systems and by the large computing power available on Pc based systems. Such integration may be provided by the implementation of the link between the two different architectures through the standard Ethernet network, whose data transfer speed is largely increasing in these years, using the TCP/IP, UDP and raw Ethernet protocols. In this paper we describe the architecture of an hybrid Ethernet based real-time control system prototype we implemented in Napoli, discussing its characteristics and performances. Finally we discuss a possible application to the real-time control of a suspended mass of the mode cleaner of the 3m prototype optical interferometer for gravitational wave detection (IDGW-3P) operational in Napoli.

Research on grid connection control technology of double fed wind generator

NASA Astrophysics Data System (ADS)

Ling, Li

2017-01-01

The composition and working principle of variable speed constant frequency doubly fed wind power generation system is discussed in this thesis. On the basis of theoretical analysis and control on the modeling, the doubly fed wind power generation simulation control system is designed based on a TMS320F2407 digital signal processor (DSP), and has done a large amount of experimental research, which mainly include, variable speed constant frequency, constant pressure, Grid connected control experiment. The running results show that the design of simulation control system is reasonable and can meet the need of experimental research.

DHMI: dynamic holographic microscopy interface

NASA Astrophysics Data System (ADS)

He, Xuefei; Zheng, Yujie; Lee, Woei Ming

2016-12-01

Digital holographic microscopy (DHM) is a powerful in-vitro biological imaging tool. In this paper, we report a fully automated off-axis digital holographic microscopy system completed with a graphical user interface in the Matlab environment. The interface primarily includes Fourier domain processing, phase reconstruction, aberration compensation and autofocusing. A variety of imaging operations such as region of interest selection, de-noising mode (filtering and averaging), low frame rate imaging for immediate reconstruction and high frame rate imaging routine ( 27 fps) are implemented to facilitate ease of use.

A Study of Power Systems Stability Enhancement Effects by Excitation Control of Superconducting Generator with High Response Excitation based on Detailed Excitation Circuit Model

NASA Astrophysics Data System (ADS)

Wu, Guohong; Shirato, Hideyuki

SCG (Superconducting Generator) has a superconducting field winding, which leads to many advantages such as small size, high generation efficiency, low impedance, and so on, and be considered as one of the candidates to meet the needs of high stability and high efficiency in the future power system networks. SCG with high response excitation is especially expected to be able to enhance the transient stability of power system by its SMES (Superconducting Magnetic Energy System) effect. The SMES effect of SCG is recognized that its behaviors are dominated by the structures and controls of its excitation system. For this reason, in order to verify exactly how the SMES effect of SCG influences on the power system stability, the electrical circuits of SCG high response excitation are modeled in detail for conducting digital simulation, and its influence on excitation voltage and active power output of SCG are discussed as well. The simulation results with a typical one machine - infinite bus power system model shows that the SMES effect can be certainly obtained when its exciting power is supplied from SCG terminal bus and may considerably lead to an improvement of power system transient stability.

Advanced Data Acquisition Systems

NASA Technical Reports Server (NTRS)

Perotti, J.

2003-01-01

Current and future requirements of the aerospace sensors and transducers field make it necessary for the design and development of new data acquisition devices and instrumentation systems. New designs are sought to incorporate self-health, self-calibrating, self-repair capabilities, allowing greater measurement reliability and extended calibration cycles. With the addition of power management schemes, state-of-the-art data acquisition systems allow data to be processed and presented to the users with increased efficiency and accuracy. The design architecture presented in this paper displays an innovative approach to data acquisition systems. The design incorporates: electronic health self-check, device/system self-calibration, electronics and function self-repair, failure detection and prediction, and power management (reduced power consumption). These requirements are driven by the aerospace industry need to reduce operations and maintenance costs, to accelerate processing time and to provide reliable hardware with minimum costs. The project's design architecture incorporates some commercially available components identified during the market research investigation like: Field Programmable Gate Arrays (FPGA) Programmable Analog Integrated Circuits (PAC IC) and Field Programmable Analog Arrays (FPAA); Digital Signal Processing (DSP) electronic/system control and investigation of specific characteristics found in technologies like: Electronic Component Mean Time Between Failure (MTBF); and Radiation Hardened Component Availability. There are three main sections discussed in the design architecture presented in this document. They are the following: (a) Analog Signal Module Section, (b) Digital Signal/Control Module Section and (c) Power Management Module Section. These sections are discussed in detail in the following pages. This approach to data acquisition systems has resulted in the assignment of patent rights to Kennedy Space Center under U.S. patent # 6,462,684. Furthermore, NASA KSC commercialization office has issued licensing rights to Circuit Avenue Netrepreneurs, LLC , a minority-owned business founded in 1999 located in Camden, NJ.

Real-time phase correlation based integrated system for seizure detection

NASA Astrophysics Data System (ADS)

Romaine, James B.; Delgado-Restituto, Manuel; Leñero-Bardallo, Juan A.; Rodríguez-Vázquez, Ángel

2017-05-01

This paper reports a low area, low power, integer-based digital processor for the calculation of phase synchronization between two neural signals. The processor calculates the phase-frequency content of a signal by identifying the specific time periods associated with two consecutive minima. The simplicity of this phase-frequency content identifier allows for the digital processor to utilize only basic digital blocks, such as registers, counters, adders and subtractors, without incorporating any complex multiplication and or division algorithms. In fact, the processor, fabricated in a 0.18μm CMOS process, only occupies an area of 0.0625μm2 and consumes 12.5nW from a 1.2V supply voltage when operated at 128kHz. These low-area, low-power features make the proposed processor a valuable computing element in closed loop neural prosthesis for the treatment of neural diseases, such as epilepsy, or for extracting functional connectivity maps between different recording sites in the brain.

RF digital-to-analog converter

DOEpatents

Conway, Patrick H.; Yu, David U. L.

1995-01-01

A digital-to analogue converter for producing an RF output signal proportional to a digital input word of N bits from an RF reference input, N being an integer greater or equal to 2. The converter comprises a plurality of power splitters, power combiners and a plurality of mixers or RF switches connected in a predetermined configuration.

75 FR 63766 - Digital Low Power Television, Television Translator, and Television Booster Stations and Digital...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-18

... Displacement Application. Form Numbers: FCC Form 346. Type of Review: Revision of a currently approved... Displacement Application. The Commission proposes to require all low power station with facilities on out-of- core channels (channels 52-59) to submit a digital displacement (FCC Form 346) application proposing an...

Archive of digital chirp subbottom profile data collected during USGS Cruise 13GFP01, Brownlee Dam and Hells Canyon Reservoir, Idaho and Oregon, 2013

USGS Publications Warehouse

Forde, Arnell S.; Dadisman, Shawn V.; Flocks, James G.; Fosness, Ryan L.; Welcker, Chris; Kelso, Kyle W.

2014-01-01

From March 16 - 31, 2013, the U.S. Geological Survey in cooperation with the Idaho Power Company conducted a geophysical survey to investigate sediment deposits and long-term sediment transport within the Snake River from Brownlee Dam to Hells Canyon Reservoir, along the Idaho and Oregon border; this effort will help the USGS to better understand geologic processes. This report serves as an archive of unprocessed digital chirp subbottom data, trackline maps, navigation files, Geographic Information System (GIS) files, Field Activity Collection System (FACS) logs, and formal Federal Geographic Data Committee (FGDC) metadata. Gained (showing a relative increase in signal amplitude) digital images of the seismic profiles are also provided. Refer to the Acronyms page for expansions of acronyms and abbreviations used in this report.

Compressed sensing: Radar signal detection and parameter measurement for EW applications

NASA Astrophysics Data System (ADS)

Rao, M. Sreenivasa; Naik, K. Krishna; Reddy, K. Maheshwara

2016-09-01

State of the art system development is very much required for UAVs (Unmanned Aerial Vehicle) and other airborne applications, where miniature, lightweight and low-power specifications are essential. Currently, the airborne Electronic Warfare (EW) systems are developed with digital receiver technology using Nyquist sampling. The detection of radar signals and parameter measurement is a necessary requirement in EW digital receivers. The Random Modulator Pre-Integrator (RMPI) can be used for matched detection of signals using smashed filter. RMPI hardware eliminates the high sampling rate analog to digital computer and reduces the number of samples using random sampling and detection of sparse orthonormal basis vectors. RMPI explore the structural and geometrical properties of the signal apart from traditional time and frequency domain analysis for improved detection. The concept has been proved with the help of MATLAB and LabVIEW simulations.

MEMS based digital transform spectrometers

NASA Astrophysics Data System (ADS)

Geller, Yariv; Ramani, Mouli

2005-09-01

Earlier this year, a new breed of Spectrometers based on Micro-Electro-Mechanical-System (MEMS) engines has been introduced to the commercial market. The use of these engines combined with transform mathematics, produces powerful spectrometers at unprecedented low cost in various spectral regions.

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

Lai, Jih-Sheng

This paper introduces control system design based softwares, SIMNON and MATLAB/SIMULINK, for power electronics system simulation. A complete power electronics system typically consists of a rectifier bridge along with its smoothing capacitor, an inverter, and a motor. The system components, featuring discrete or continuous, linear or nonlinear, are modeled in mathematical equations. Inverter control methods,such as pulse-width-modulation and hysteresis current control, are expressed in either computer algorithms or digital circuits. After describing component models and control methods, computer programs are then developed for complete systems simulation. Simulation results are mainly used for studying system performances, such as input and outputmore » current harmonics, torque ripples, and speed responses. Key computer programs and simulation results are demonstrated for educational purposes.« less

Finger-Powered Electro-Digital-Microfluidics.

PubMed

Peng, Cheng; Ju, Y Sungtaek

2017-01-01

Portable microfluidic devices are promising for point-of-care (POC) diagnosis and bio- and environmental surveillance in resource-constrained or non-laboratory environments. Lateral-flow devices, some built off paper or strings, have been widely developed but the fixed layouts of their underlying wicking/microchannel structures limit their flexibility and present challenges in implementing multistep reactions. Digital microfluidics can circumvent these difficulties by addressing discrete droplets individually. Existing approaches to digital microfluidics, however, often require bulky power supplies/batteries and high voltage circuits. We present a scheme to drive digital microfluidic devices by converting mechanical energy of human fingers to electrical energy using an array of piezoelectric elements. We describe the integration our scheme into two promising digital microfluidics platforms: one based on the electro-wetting-on-dielectric (EWOD) phenomenon and the other on the electrophoretic control of droplet (EPD). Basic operations of droplet manipulations, such as droplet transport, merging and splitting, are demonstrated using the finger-powered digital-microfluidics.

Numerical System Solver Developed for the National Cycle Program

NASA Technical Reports Server (NTRS)

Binder, Michael P.

1999-01-01

As part of the National Cycle Program (NCP), a powerful new numerical solver has been developed to support the simulation of aeropropulsion systems. This software uses a hierarchical object-oriented design. It can provide steady-state and time-dependent solutions to nonlinear and even discontinuous problems typically encountered when aircraft and spacecraft propulsion systems are simulated. It also can handle constrained solutions, in which one or more factors may limit the behavior of the engine system. Timedependent simulation capabilities include adaptive time-stepping and synchronization with digital control elements. The NCP solver is playing an important role in making the NCP a flexible, powerful, and reliable simulation package.

The CMOS integration of a power inverter

NASA Astrophysics Data System (ADS)

Mannarino, Eric Francis

Due to their falling costs, the use of renewable energy systems is expanding around the world. These systems require the conversion of DC power into grid-synchronous AC power. Currently, the inverters that carry out this task are built using discrete transistors. TowerJazz Semiconductor Corp. has created a commercial CMOS process that allows for blocking voltages of up to 700 V, effectively removing the barrier to integrating power inverters onto a single chip. This thesis explores this process using two topologies. The first is a cell-based switched-capacitor topology first presented by Ke Zou. The second is a novel topology that explores the advantage of using a bused input-output system, as in digital electronics. Simulations run on both topologies confirm the high-efficiency demonstrated in Zou’s process as well as the advantage the bus-based system has in output voltage levels.

DC-DC Type High-Frequency Link DC for Improved Power Quality of Cascaded Multilevel Inverter

NASA Astrophysics Data System (ADS)

Sadikin, Muhammad; Senjyu, Tomonobu; Yona, Atsushi

2013-06-01

Multilevel inverters are emerging as a new breed of power converter options for power system applications. Recent advances in power switching devices enabled the suitability of multilevel inverters for high voltage and high power applications because they are connecting several devices in series without the need of component matching. Usually, a transformerless battery energy storage system, based on a cascaded multilevel inverter, is used as a measure for voltage and frequency deviations. System can be reduced in size, weight, and cost of energy storage system. High-frequency link circuit topology is advantageous in realizing compact and light-weight power converters for uninterruptible power supply systems, new energy systems using photovoltaic-cells, fuel-cells and so on. This paper presents a DC-DC type high-frequency link DC (HFLDC) cascaded multilevel inverter. Each converter cell is implemented a control strategy for two H-bridge inverters that are controlled with the same multicarrier pulse width modulation (PWM) technique. The proposed cascaded multilevel inverter generates lower voltage total harmonic distortion (THD) in comparison with conventional cascaded multilevel inverter. Digital simulations are carried out using PSCAD/EMTDC to validate the performance of the proposed cascaded multilevel inverter.

Flight evaluation of a hydromechanical backup control for the digital electronic engine control system in an F100 engine

NASA Technical Reports Server (NTRS)

Walsh, K. R.; Burcham, F. W.

1984-01-01

The backup control (BUC) features, the operation of the BUC system, the BUC control logic, and the BUC flight test results are described. The flight test results include: (1) transfers to the BUC at military and maximum power settings; (2) a military power acceleration showing comparisons bvetween flight and simulation for BUC and primary modes; (3) steady-state idle power showing idle compressor speeds at different flight conditions; and (4) idle-to-military power BUC transients showing where cpmpressor stalls occurred for different ramp rates and idle speeds. All the BUC transfers which occur during the DEEC flight program are initiated by the pilot. Automatic transfers to the BUC do not occur.

Geologic analyses of LANDSAT-1 multispectral imagery of a possible power plant site employing digital and analog image processing. [in Pennsylvania

NASA Technical Reports Server (NTRS)

Lovegreen, J. R.; Prosser, W. J.; Millet, R. A.

1975-01-01

A site in the Great Valley subsection of the Valley and Ridge physiographic province in eastern Pennsylvania was studied to evaluate the use of digital and analog image processing for geologic investigations. Ground truth at the site was obtained by a field mapping program, a subsurface exploration investigation and a review of available published and unpublished literature. Remote sensing data were analyzed using standard manual techniques. LANDSAT-1 imagery was analyzed using digital image processing employing the multispectral Image 100 system and using analog color processing employing the VP-8 image analyzer. This study deals primarily with linears identified employing image processing and correlation of these linears with known structural features and with linears identified manual interpretation; and the identification of rock outcrops in areas of extensive vegetative cover employing image processing. The results of this study indicate that image processing can be a cost-effective tool for evaluating geologic and linear features for regional studies encompassing large areas such as for power plant siting. Digital image processing can be an effective tool for identifying rock outcrops in areas of heavy vegetative cover.

Controlled power delivery for super-resolution imaging of biological samples using digital micromirror device

NASA Astrophysics Data System (ADS)

Valiya Peedikakkal, Liyana; Cadby, Ashley

2017-02-01

Localization based super resolution images of a biological sample is generally achieved by using high power laser illumination with long exposure time which unfortunately increases photo-toxicity of a sample, making super resolution microscopy, in general, incompatible with live cell imaging. Furthermore, the limitation of photobleaching reduces the ability to acquire time lapse images of live biological cells using fluorescence microscopy. Digital Light Processing (DLP) technology can deliver light at grey scale levels by flickering digital micromirrors at around 290 Hz enabling highly controlled power delivery to samples. In this work, Digital Micromirror Device (DMD) is implemented in an inverse Schiefspiegler telescope setup to control the power and pattern of illumination for super resolution microscopy. We can achieve spatial and temporal patterning of illumination by controlling the DMD pixel by pixel. The DMD allows us to control the power and spatial extent of the laser illumination. We have used this to show that we can reduce the power delivered to the sample to allow for longer time imaging in one area while achieving sub-diffraction STORM imaging in another using higher power densities.

Low-power analog integrated circuits for wireless ECG acquisition systems.

PubMed

Tsai, Tsung-Heng; Hong, Jia-Hua; Wang, Liang-Hung; Lee, Shuenn-Yuh

2012-09-01

This paper presents low-power analog ICs for wireless ECG acquisition systems. Considering the power-efficient communication in the body sensor network, the required low-power analog ICs are developed for a healthcare system through miniaturization and system integration. To acquire the ECG signal, a low-power analog front-end system, including an ECG signal acquisition board, an on-chip low-pass filter, and an on-chip successive-approximation analog-to-digital converter for portable ECG detection devices is presented. A quadrature CMOS voltage-controlled oscillator and a 2.4 GHz direct-conversion transmitter with a power amplifier and upconversion mixer are also developed to transmit the ECG signal through wireless communication. In the receiver, a 2.4 GHz fully integrated CMOS RF front end with a low-noise amplifier, differential power splitter, and quadrature mixer based on current-reused folded architecture is proposed. The circuits have been implemented to meet the specifications of the IEEE 802.15.4 2.4 GHz standard. The low-power ICs of the wireless ECG acquisition systems have been fabricated using a 0.18 μm Taiwan Semiconductor Manufacturing Company (TSMC) CMOS standard process. The measured results on the human body reveal that ECG signals can be acquired effectively by the proposed low-power analog front-end ICs.

DEFENSE SCIENCE AND TECHNOLOGY Adopting Best Practices Can Improve Innovation Investments and Management

DTIC Science & Technology

2017-06-01

automation, and digitalization technologies. Siemens’s products include gas, steam, and wind turbines , integrated power plant solutions, power grid...Quick Reaction responds to urgent technology needs and solves problems for warfighters. Existing systems refers to projects responsive to immediate...polymer, chemical and biological science to help address many of the world’s most challenging problems , such as the need for fresh food, safer and

Achieving supercomputer performance for neural net simulation with an array of digital signal processors

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

Muller, U.A.; Baumle, B.; Kohler, P.

1992-10-01

Music, a DSP-based system with a parallel distributed-memory architecture, provides enormous computing power yet retains the flexibility of a general-purpose computer. Reaching a peak performance of 2.7 Gflops at a significantly lower cost, power consumption, and space requirement than conventional supercomputers, Music is well suited to computationally intensive applications such as neural network simulation. 12 refs., 9 figs., 2 tabs.

Hybrid photonic signal processing

NASA Astrophysics Data System (ADS)

Ghauri, Farzan Naseer

This thesis proposes research of novel hybrid photonic signal processing systems in the areas of optical communications, test and measurement, RF signal processing and extreme environment optical sensors. It will be shown that use of innovative hybrid techniques allows design of photonic signal processing systems with superior performance parameters and enhanced capabilities. These applications can be divided into domains of analog-digital hybrid signal processing applications and free-space---fiber-coupled hybrid optical sensors. The analog-digital hybrid signal processing applications include a high-performance analog-digital hybrid MEMS variable optical attenuator that can simultaneously provide high dynamic range as well as high resolution attenuation controls; an analog-digital hybrid MEMS beam profiler that allows high-power watt-level laser beam profiling and also provides both submicron-level high resolution and wide area profiling coverage; and all optical transversal RF filters that operate on the principle of broadband optical spectral control using MEMS and/or Acousto-Optic tunable Filters (AOTF) devices which can provide continuous, digital or hybrid signal time delay and weight selection. The hybrid optical sensors presented in the thesis are extreme environment pressure sensors and dual temperature-pressure sensors. The sensors employ hybrid free-space and fiber-coupled techniques for remotely monitoring a system under simultaneous extremely high temperatures and pressures.

Portable power source needs of the future Army -- Batteries and fuel cells

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

Jacobs, R.; Christopher, H.; Hamlen, R.

This paper describes the US Army`s future needs for silent portable power in the area of batteries and fuel cells. These needs will continue to increase as a result of the introduction of newer types of equipment, the increasing digitization of the battlefield, and future integrated Soldier Systems. Current battery programs are aimed at improved, low-cost primary batteries, and rechargeable batteries with increased energy densities. The Army fuel cell program aimed at portable systems capable of the order of 150W is also described.

Nuclear Science Symposium, 4th, and Nuclear Power Systems Symposium, 9th, San Francisco, Calif., October 19-21, 1977, Proceedings

NASA Technical Reports Server (NTRS)

1978-01-01

Consideration is given to the following types of high energy physics instrumentation: drift chambers, multiwire proportional chambers, calorimeters, optical detectors, ionization and scintillation detectors, solid state detectors, and electronic and digital subsystems. Attention is also paid to reactor instrumentation, nuclear medicine instrumentation, data acquisition systems for nuclear instrumentation, microprocessor applications in nuclear science, environmental instrumentation, control and instrumentation of nuclear power generating stations, and radiation monitoring. Papers are also presented on instrumentation for the High Energy Astronomy Observatory.

Frequency stabilization for mobile satellite terminals via LORAN

NASA Technical Reports Server (NTRS)

Ernst, Gregory J.; Kee, Steven M.; Marquart, Robert C.

1990-01-01

Digital satellite communication systems require careful management of frequency stability. Historically, frequency stability has been accomplished by continuously powered, high cost, high performance reference oscillators. Today's low cost mobile satellite communication equipment must operate under wide ranging environmental conditions, stabilize quickly after application of power, and provide adequate performance margin to overcome RF link impairments unique to the land mobile environment. Methods for frequency stabilization in land mobile applications must meet these objectives without incurring excessive performance degradation. A frequency stabilization scheme utilizing the LORAN (Long Range Navigation) system is presented.

Skylab Rescue Space Vehicle OAT No. 1 Plugs in Test

NASA Technical Reports Server (NTRS)

Jevitt, S. J.

1973-01-01

A test is described which demonstrates the compatibility of the Skylab Rescue Space Vehicle systems, the ground support equipment, and off-site support facilities by proceeding through a simulated launch countdown, liftoff, and flight. The functions of propellant loading, umbilical ejection, holddown arm release, service arm retraction, liftoff, and inflight separation are simulated. An external power source supplies transfer power to internal, and instrument unit commands are simulated by the digital command system. The test outline is presented along with a list of references, intercommunications information, radio frequency matrix, and interface control chart.

Modeling and Compensation Design for a Power Hardware-in-the-Loop Simulation of an AC Distribution System

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

Ainsworth, Nathan; Hariri, Ali; Prabakar, Kumaraguru

Power hardware-in-the-loop (PHIL) simulation, where actual hardware under text is coupled with a real-time digital model in closed loop, is a powerful tool for analyzing new methods of control for emerging distributed power systems. However, without careful design and compensation of the interface between the simulated and actual systems, PHIL simulations may exhibit instability and modeling inaccuracies. This paper addresses issues that arise in the PHIL simulation of a hardware battery inverter interfaced with a simulated distribution feeder. Both the stability and accuracy issues are modeled and characterized, and a methodology for design of PHIL interface compensation to ensure stabilitymore » and accuracy is presented. The stability and accuracy of the resulting compensated PHIL simulation is then shown by experiment.« less

Modeling and Compensation Design for a Power Hardware-in-the-Loop Simulation of an AC Distribution System: Preprint

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

Prabakar, Kumaraguru; Ainsworth, Nathan; Pratt, Annabelle

Power hardware-in-the-loop (PHIL) simulation, where actual hardware under text is coupled with a real-time digital model in closed loop, is a powerful tool for analyzing new methods of control for emerging distributed power systems. However, without careful design and compensation of the interface between the simulated and actual systems, PHIL simulations may exhibit instability and modeling inaccuracies. This paper addresses issues that arise in the PHIL simulation of a hardware battery inverter interfaced with a simulated distribution feeder. Both the stability and accuracy issues are modeled and characterized, and a methodology for design of PHIL interface compensation to ensure stabilitymore » and accuracy is presented. The stability and accuracy of the resulting compensated PHIL simulation is then shown by experiment.« less

Fast, Low-Power, Hysteretic Level-Detector Circuit

NASA Technical Reports Server (NTRS)

Arditti, Mordechai

1993-01-01

Circuit for detection of preset levels of voltage or current intended to replace standard fast voltage comparator. Hysteretic analog/digital level detector operates at unusually low power with little sacrifice of speed. Comprises low-power analog circuit and complementary metal oxide/semiconductor (CMOS) digital circuit connected in overall closed feedback loop to decrease rise and fall times, provide hysteresis, and trip-level control. Contains multiple subloops combining linear and digital feedback. Levels of sensed signals and hysteresis level easily adjusted by selection of components to suit specific application.

APPLEPIPS /Apple Personal Image Processing System/ - An interactive digital image processing system for the Apple II microcomputer

NASA Technical Reports Server (NTRS)

Masuoka, E.; Rose, J.; Quattromani, M.

1981-01-01

Recent developments related to microprocessor-based personal computers have made low-cost digital image processing systems a reality. Image analysis systems built around these microcomputers provide color image displays for images as large as 256 by 240 pixels in sixteen colors. Descriptive statistics can be computed for portions of an image, and supervised image classification can be obtained. The systems support Basic, Fortran, Pascal, and assembler language. A description is provided of a system which is representative of the new microprocessor-based image processing systems currently on the market. While small systems may never be truly independent of larger mainframes, because they lack 9-track tape drives, the independent processing power of the microcomputers will help alleviate some of the turn-around time problems associated with image analysis and display on the larger multiuser systems.

A comparison of the performance of digital mammography systems.

PubMed

Monnin, P; Gutierrez, D; Bulling, S; Guntern, D; Verdun, F R

2007-03-01

An objective analysis of image quality parameters was performed for six digital mammography systems. The presampled modulation transfer function (MTF), normalized noise power spectrum (NNPS), and detective quantum efficiency (DQE) for the systems were determined at different doses, for 28 kVp with a Mo/Mo or W/Al target/filter combination and 2 mm of additional aluminium filtration. The flat-panel units have higher MTF and DQE in the mid to high frequency range than standard CR systems. The highest DQE, over the whole dose range, is for the slit-scanning direct photon counting system. Dual-side read CR can overcome the inherent x-ray absorption and signal collection limitations of standard CR mammography, improving the low-frequency DQE by 40%, to the same level as full-field systems, but it does not improve the poor spatial resolution of phosphor.

High-Speed Noninvasive Eye-Tracking System

NASA Technical Reports Server (NTRS)

Talukder, Ashit; LaBaw, Clayton; Michael-Morookian, John; Monacos, Steve; Serviss, Orin

2007-01-01

The figure schematically depicts a system of electronic hardware and software that noninvasively tracks the direction of a person s gaze in real time. Like prior commercial noninvasive eye-tracking systems, this system is based on (1) illumination of an eye by a low-power infrared light-emitting diode (LED); (2) acquisition of video images of the pupil, iris, and cornea in the reflected infrared light; (3) digitization of the images; and (4) processing the digital image data to determine the direction of gaze from the centroids of the pupil and cornea in the images. Relative to the prior commercial systems, the present system operates at much higher speed and thereby offers enhanced capability for applications that involve human-computer interactions, including typing and computer command and control by handicapped individuals,and eye-based diagnosis of physiological disorders that affect gaze responses.

Simulation Accelerator

NASA Technical Reports Server (NTRS)

1998-01-01

Under a NASA SBIR (Small Business Innovative Research) contract, (NAS5-30905), EAI Simulation Associates, Inc., developed a new digital simulation computer, Starlight(tm). With an architecture based on the analog model of computation, Starlight(tm) outperforms all other computers on a wide range of continuous system simulation. This system is used in a variety of applications, including aerospace, automotive, electric power and chemical reactors.

The dish-Rankine SCSTPE program (Engineering Experiment no. 1). [systems engineering and economic analysis for a small community solar thermal electric system

NASA Technical Reports Server (NTRS)

Pons, R. L.; Grigsby, C. E.

1980-01-01

Activities planned for phase 2 Of the Small Community Solar Thermal Power Experiment (PFDR) program are summarized with emphasis on a dish-Rankine point focusing distributed receiver solar thermal electric system. Major design efforts include: (1) development of an advanced concept indirect-heated receiver;(2) development of hardware and software for a totally unmanned power plant control system; (3) implementation of a hybrid digital simulator which will validate plant operation prior to field testing; and (4) the acquisition of an efficient organic Rankine cycle power conversion unit. Preliminary performance analyses indicate that a mass-produced dish-Rankine PFDR system is potentially capable of producing electricity at a levelized busbar energy cost of 60 to 70 mills per KWh and with a capital cost of about $1300 per KW.

Feasibility of an ultra-low power digital signal processor platform as a basis for a fully implantable brain-computer interface system.

PubMed

Wang, Po T; Gandasetiawan, Keulanna; McCrimmon, Colin M; Karimi-Bidhendi, Alireza; Liu, Charles Y; Heydari, Payam; Nenadic, Zoran; Do, An H

2016-08-01

A fully implantable brain-computer interface (BCI) can be a practical tool to restore independence to those affected by spinal cord injury. We envision that such a BCI system will invasively acquire brain signals (e.g. electrocorticogram) and translate them into control commands for external prostheses. The feasibility of such a system was tested by implementing its benchtop analogue, centered around a commercial, ultra-low power (ULP) digital signal processor (DSP, TMS320C5517, Texas Instruments). A suite of signal processing and BCI algorithms, including (de)multiplexing, Fast Fourier Transform, power spectral density, principal component analysis, linear discriminant analysis, Bayes rule, and finite state machine was implemented and tested in the DSP. The system's signal acquisition fidelity was tested and characterized by acquiring harmonic signals from a function generator. In addition, the BCI decoding performance was tested, first with signals from a function generator, and subsequently using human electroencephalogram (EEG) during eyes opening and closing task. On average, the system spent 322 ms to process and analyze 2 s of data. Crosstalk (<;-65 dB) and harmonic distortion (~1%) were minimal. Timing jitter averaged 49 μs per 1000 ms. The online BCI decoding accuracies were 100% for both function generator and EEG data. These results show that a complex BCI algorithm can be executed on an ULP DSP without compromising performance. This suggests that the proposed hardware platform may be used as a basis for future, fully implantable BCI systems.

High-speed and high-resolution quantitative phase imaging with digital-micromirror device-based illumination (Conference Presentation)

NASA Astrophysics Data System (ADS)

Zhou, Renjie; Jin, Di; Yaqoob, Zahid; So, Peter T. C.

2017-02-01

Due to the large number of available mirrors, the patterning speed, low-cost, and compactness, digital-micromirror devices (DMDs) have been extensively used in biomedical imaging system. Recently, DMDs have been brought to the quantitative phase microscopy (QPM) field to achieve synthetic-aperture imaging and tomographic imaging. Last year, our group demonstrated using DMD for QPM, where the phase-retrieval is based on a recently developed Fourier ptychography algorithm. In our previous system, the illumination angle was varied through coding the aperture plane of the illumination system, which has a low efficiency on utilizing the laser power. In our new DMD-based QPM system, we use the Lee-holograms, which is conjugated to the sample plane, to change the illumination angles for much higher power efficiency. Multiple-angle illumination can also be achieved with this method. With this versatile system, we can achieve FPM-based high-resolution phase imaging with 250 nm lateral resolution using the Rayleigh criteria. Due to the use of a powerful laser, the imaging speed would only be limited by the camera acquisition speed. With a fast camera, we expect to achieve close to 100 fps phase imaging speed that has not been achieved in current FPM imaging systems. By adding reference beam, we also expect to achieve synthetic-aperture imaging while directly measuring the phase of the sample fields. This would reduce the phase-retrieval processing time to allow for real-time imaging applications in the future.

RF digital-to-analog converter

DOEpatents

Conway, P.H.; Yu, D.U.L.

1995-02-28

A digital-to-analog converter is disclosed for producing an RF output signal proportional to a digital input word of N bits from an RF reference input, N being an integer greater or equal to 2. The converter comprises a plurality of power splitters, power combiners and a plurality of mixers or RF switches connected in a predetermined configuration. 18 figs.

Reprint of “Performance analysis of a model-sized superconducting DC transmission system based VSC-HVDC transmission technologies using RTDS”

NASA Astrophysics Data System (ADS)

Dinh, Minh-Chau; Ju, Chang-Hyeon; Kim, Sung-Kyu; Kim, Jin-Geun; Park, Minwon; Yu, In-Keun

2013-01-01

The combination of a high temperature superconducting DC power cable and a voltage source converter based HVDC (VSC-HVDC) creates a new option for transmitting power with multiple collection and distribution points for long distance and bulk power transmissions. It offers some greater advantages compared with HVAC or conventional HVDC transmission systems, and it is well suited for the grid integration of renewable energy sources in existing distribution or transmission systems. For this reason, a superconducting DC transmission system based HVDC transmission technologies is planned to be set up in the Jeju power system, Korea. Before applying this system to a real power system on Jeju Island, system analysis should be performed through a real time test. In this paper, a model-sized superconducting VSC-HVDC system, which consists of a small model-sized VSC-HVDC connected to a 2 m YBCO HTS DC model cable, is implemented. The authors have performed the real-time simulation method that incorporates the model-sized superconducting VSC-HVDC system into the simulated Jeju power system using Real Time Digital Simulator (RTDS). The performance analysis of the superconducting VSC-HVDC systems has been verified by the proposed test platform and the results were discussed in detail.

Performance analysis of a model-sized superconducting DC transmission system based VSC-HVDC transmission technologies using RTDS

NASA Astrophysics Data System (ADS)

Dinh, Minh-Chau; Ju, Chang-Hyeon; Kim, Sung-Kyu; Kim, Jin-Geun; Park, Minwon; Yu, In-Keun

2012-08-01

The combination of a high temperature superconducting DC power cable and a voltage source converter based HVDC (VSC-HVDC) creates a new option for transmitting power with multiple collection and distribution points for long distance and bulk power transmissions. It offers some greater advantages compared with HVAC or conventional HVDC transmission systems, and it is well suited for the grid integration of renewable energy sources in existing distribution or transmission systems. For this reason, a superconducting DC transmission system based HVDC transmission technologies is planned to be set up in the Jeju power system, Korea. Before applying this system to a real power system on Jeju Island, system analysis should be performed through a real time test. In this paper, a model-sized superconducting VSC-HVDC system, which consists of a small model-sized VSC-HVDC connected to a 2 m YBCO HTS DC model cable, is implemented. The authors have performed the real-time simulation method that incorporates the model-sized superconducting VSC-HVDC system into the simulated Jeju power system using Real Time Digital Simulator (RTDS). The performance analysis of the superconducting VSC-HVDC systems has been verified by the proposed test platform and the results were discussed in detail.

Load sensing system

DOEpatents

Sohns, Carl W.; Nodine, Robert N.; Wallace, Steven Allen

1999-01-01

A load sensing system inexpensively monitors the weight and temperature of stored nuclear material for long periods of time in widely variable environments. The system can include an electrostatic load cell that encodes weight and temperature into a digital signal which is sent to a remote monitor via a coaxial cable. The same cable is used to supply the load cell with power. When multiple load cells are used, vast

Real-time optical fiber digital speckle pattern interferometry for industrial applications

NASA Astrophysics Data System (ADS)

Chan, Robert K.; Cheung, Y. M.; Lo, C. H.; Tam, T. K.

1997-03-01

There is current interest, especially in the industrial sector, to use the digital speckle pattern interferometry (DSPI) technique to measure surface stress. Indeed, many publications in the subject are evident of the growing interests in the field. However, to bring the technology to industrial use requires the integration of several emerging technologies, viz. optics, feedback control, electronics, imaging processing and digital signal processing. Due to the highly interdisciplinary nature of the technique, successful implementation and development require expertise in all of the fields. At Baptist University, under the funding of a major industrial grant, we are developing the technology for the industrial sector. Our system fully exploits optical fibers and diode lasers in the design to enable practical and rugged systems suited for industrial applications. Besides the development in optics, we have broken away from the reliance of a microcomputer PC platform for both image capture and processing, and have developed a digital signal processing array system that can handle simultaneous and independent image capture/processing with feedback control. The system, named CASPA for 'cascadable architecture signal processing array,' is a third generation development system that utilizes up to 7 digital signal processors has proved to be a very powerful system. With our CASPA we are now in a better position to developing novel optical measurement systems for industrial application that may require different measurement systems to operate concurrently and requiring information exchange between the systems. Applications in mind such as simultaneous in-plane and out-of-plane DSPI image capture/process, vibrational analysis with interactive DSPI and phase shifting control of optical systems are a few good examples of the potentials.

47 CFR 74.710 - Digital low power TV and TV translator station protection.

Code of Federal Regulations, 2012 CFR

2012-10-01

... SERVICES Low Power TV, TV Translator, and TV Booster Stations § 74.710 Digital low power TV and TV... booster station or change the facilities of an existing station will not be accepted if it fails to... filed prior to the date the low power TV, TV translator, or TV booster application is filed. (b...

47 CFR 74.710 - Digital low power TV and TV translator station protection.

Code of Federal Regulations, 2011 CFR

2011-10-01

... SERVICES Low Power TV, TV Translator, and TV Booster Stations § 74.710 Digital low power TV and TV... booster station or change the facilities of an existing station will not be accepted if it fails to... filed prior to the date the low power TV, TV translator, or TV booster application is filed. (b...

47 CFR 74.710 - Digital low power TV and TV translator station protection.

Code of Federal Regulations, 2014 CFR

2014-10-01

... SERVICES Low Power TV, TV Translator, and TV Booster Stations § 74.710 Digital low power TV and TV... booster station or change the facilities of an existing station will not be accepted if it fails to... filed prior to the date the low power TV, TV translator, or TV booster application is filed. (b...

47 CFR 74.710 - Digital low power TV and TV translator station protection.

Code of Federal Regulations, 2013 CFR

2013-10-01

... SERVICES Low Power TV, TV Translator, and TV Booster Stations § 74.710 Digital low power TV and TV... booster station or change the facilities of an existing station will not be accepted if it fails to... filed prior to the date the low power TV, TV translator, or TV booster application is filed. (b...

Measuring noise equivalent irradiance of a digital short-wave infrared imaging system using a broadband source to simulate the night spectrum

NASA Astrophysics Data System (ADS)

Green, John R.; Robinson, Timothy

2015-05-01

There is a growing interest in developing helmet-mounted digital imaging systems (HMDIS) for integration into military aircraft cockpits. This interest stems from the multiple advantages of digital vs. analog imaging such as image fusion from multiple sensors, data processing to enhance the image contrast, superposition of non-imaging data over the image, and sending images to remote location for analysis. There are several properties an HMDIS must have in order to aid the pilot during night operations. In addition to the resolution, image refresh rate, dynamic range, and sensor uniformity over the entire Focal Plane Array (FPA); the imaging system must have the sensitivity to detect the limited night light available filtered through cockpit transparencies. Digital sensor sensitivity is generally measured monochromatically using a laser with a wavelength near the peak detector quantum efficiency, and is generally reported as either the Noise Equivalent Power (NEP) or Noise Equivalent Irradiance (NEI). This paper proposes a test system that measures NEI of Short-Wave Infrared (SWIR) digital imaging systems using a broadband source that simulates the night spectrum. This method has a few advantages over a monochromatic method. Namely, the test conditions provide spectrum closer to what is experienced by the end-user, and the resulting NEI may be compared directly to modeled night glow irradiance calculation. This comparison may be used to assess the Technology Readiness Level of the imaging system for the application. The test system is being developed under a Cooperative Research and Development Agreement (CRADA) with the Air Force Research Laboratory.

Digital differential confocal microscopy based on spatial shift transformation.

PubMed

Liu, J; Wang, Y; Liu, C; Wilson, T; Wang, H; Tan, J

2014-11-01

Differential confocal microscopy is a particularly powerful surface profilometry technique in industrial metrology due to its high axial sensitivity and insensitivity to noise. However, the practical implementation of the technique requires the accurate positioning of point detectors in three-dimensions. We describe a simple alternative based on spatial transformation of a through-focus series of images obtained from a homemade beam scanning confocal microscope. This digital differential confocal microscopy approach is described and compared with the traditional Differential confocal microscopy approach. The ease of use of the digital differential confocal microscopy system is illustrated by performing measurements on a 3D standard specimen. © 2014 The Authors Journal of Microscopy © 2014 Royal Microscopical Society.

Engineering studies related to Skylab program. [assessment of automatic gain control data

NASA Technical Reports Server (NTRS)

Hayne, G. S.

1973-01-01

The relationship between the S-193 Automatic Gain Control data and the magnitude of received signal power was studied in order to characterize performance parameters for Skylab equipment. The r-factor was used for the assessment and is defined to be less than unity, and a function of off-nadir angle, ocean surface roughness, and receiver signal to noise ratio. A digital computer simulation was also used to assess to additive receiver, or white noise. The system model for the digital simulation is described, along with intermediate frequency and video impulse response functions used, details of the input waveforms, and results to date. Specific discussion of the digital computer programs used is also provided.

Conceptual design of the SMART dosimeter

NASA Astrophysics Data System (ADS)

Johnson, Erik B.; Vogel, Sam; Frank, Rebecca; Stoddard, Graham; Vera, Alonzo; Alexander, David; Christian, James

2017-08-01

Active dosimeters for astronauts and space weather monitors are critical tools for mitigating radiation induced health issues or system failure on capital equipment. Commercial spaceflight, deep space flight, and satellites require smarter, smaller, and lower power dosimeters. There are a number of instruments with flight heritage, yet as identified in NASA's roadmaps, these technologies do not lend themselves to a viable solution for active dosimetry for an astronaut, particularly for deep space missions. For future missions, nano- and micro-satellites will require compact instruments that will accurately assess the radiation hazard without consuming major resources on the spacecraft. RMD has developed the methods for growing an advanced scintillation material called phenylcarbazole, which provides pulse shape discrimination between protons and electrons. When used in combination with an anti-coincidence detector system, an assessment of the dose from charged ions and neutral particles can be determined. This is valuable as damage on a system (such as silicon or tissue) is dependent on the particle species. Using this crystal with readout electronics developed in partnership with COSMIAC at the University of New Mexico, the design of the Small Mixed field Autonomous Radiation Tracker (SMART) Dosimeter consists of a low-power analog to digital conversion scheme with low-power digital signal processing algorithms, which are to be implemented within a compact system on a chip, such as the Xilinx Zynq series. A review of the conceptual design is presented.

Digital and smart chest drainage systems to monitor air leaks: the birth of a new era?

PubMed

Cerfolio, Robert J; Varela, Gonzalo; Brunelli, Alessandro

2010-08-01

Recently, several companies have manufactured and commercialized new pleural drainage units that incorporate electronic components for the digital quantification of air through chest tubes and, in some instances, pleural pressure assessment. The goal of these systems is to objectify this previously subjective bedside clinical parameter and allow for more objective, consistent measurement of air leaks. The belief is this will lead to quicker and more accurate chest tube management. In addition, some systems feature portable suction devices. These may afford earlier mobilization of patients because the pleural drainage chamber is attached to a battery-powered smart suction device. In this article we review the clinical experiences using these new devices. Copyright 2010 Elsevier Inc. All rights reserved.

CEBAF Superconducting Cavity RF Drive System

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

Fugitt, Jock; Moore, Thomas

1987-03-01

The CEBAR RF system consists of 418 individual RF amplifier chains. Each superconducting cavity is phase locked to the master drive reference line to within 1 degree, and the cavity field gradient is regulated to within 1 part in 10 by a state-of-the-art RF control module. Precision, continuously adjustable, modulo 360 phase shifters are used to generate the individual phase references, and a compensated RF detector is used for level feedback. The close coupled digital system enhances system accuracy, provides self-calibration, and continuously checks the system for malfunction. Calibration curves, the operating program, and system history are stored in anmore » on board EEPROM. The RF power is generated by a 5Kw, water cooled, permanent magnet focused klystorn. The klystons are clustered in groups of 8 and powered from a common supply. RF power is transmitted to the accelerator sections by semiflexible waveguide.« less

Communications and control for electric power systems

NASA Technical Reports Server (NTRS)

Kirkham, H.

1992-01-01

A long-term strategy for the integration of new control technologies for power generation and delivery is proposed: the industry would benefit from an evolutionary approach that would adapt to its needs future technologies as well as those that it has so far not heeded. The integrated operation of the entire system, including the distribution system, was proposed as a future goal. The AbNET communication protocols are reviewed, and additions that were made in 1991 are described. In the original network, traffic was controlled by polling at the master station, located at the substation, and routed by a flooding algorithm. In a revised version, the polling and flooding are modified. The question of interfacing low-energy measurement transducers or instrument transformers is considered. There is presently little or no agreement on what the output of optical current transducers (CT's) should be. Appendices deal with the calibration of current transducers; with Delta modulation, a simple means of serially encoding the output of an OCT; and with noise shaping, a method of digital signal processing that trades off the number of bits in a digital sample for a higher number of samples.

Multichannel low power time-to-digital converter card with 21 ps precision and full scale range up to 10 μs

NASA Astrophysics Data System (ADS)

Tamborini, D.; Portaluppi, D.; Villa, F.; Tisa, S.; Tosi, A.

2014-11-01

We present a Time-to-Digital Converter (TDC) card with a compact form factor, suitable for multichannel timing instruments or for integration into more complex systems. The TDC Card provides 10 ps timing resolution over the whole measurement range, which is selectable from 160 ns up to 10 μs, reaching 21 ps rms precision, 1.25% LSB rms differential nonlinearity, up to 3 Mconversion/s with 400 mW power consumption. The I/O edge card connector provides timing data readout through either a parallel bus or a 100 MHz serial interface and further measurement information like input signal rate and valid conversion rate (typically useful for time-correlated single-photon counting application) through an independent serial link.

Multichannel low power time-to-digital converter card with 21 ps precision and full scale range up to 10 μs.

PubMed

Tamborini, D; Portaluppi, D; Villa, F; Tisa, S; Tosi, A

2014-11-01

We present a Time-to-Digital Converter (TDC) card with a compact form factor, suitable for multichannel timing instruments or for integration into more complex systems. The TDC Card provides 10 ps timing resolution over the whole measurement range, which is selectable from 160 ns up to 10 μs, reaching 21 ps rms precision, 1.25% LSB rms differential nonlinearity, up to 3 Mconversion/s with 400 mW power consumption. The I/O edge card connector provides timing data readout through either a parallel bus or a 100 MHz serial interface and further measurement information like input signal rate and valid conversion rate (typically useful for time-correlated single-photon counting application) through an independent serial link.

A method for the measurement and the statistical analysis of atmospheric turbulence

NASA Technical Reports Server (NTRS)

Tieleman, H. W.; Tavoularis, S. C.

1974-01-01

The instantaneous values of output voltages representing the wind velocity vector and the temperature at different elevations of the 250-foot meteorological tower located at NASA Wallops Flight Center are provided with the three dimensional split-film TSI Model 1080 anemometer system. The output voltages are sampled at a rate of one every 5 milliseconds, digitized and stored on digital magnetic tapes for a time period of approximately 40 minutes, with the use of a specially designed data acqusition system. A new calibration procedure permits the conversion of the digital voltages to the respective values of the temperature and the velocity components in a Cartesian coordinate system connected with the TSI probe with considerable accuracy. Power, cross, coincidence and quadrature spectra of the wind components and the temperature are obtained with the use of the fast Fourier transform. The cosine taper data window and ensemble and frequency smoothing techniques are used to provide smooth estimates of the spectral functions.

Advanced Signal Conditioners for Data-Acquisition Systems

NASA Technical Reports Server (NTRS)

Lucena, Angel; Perotti, Jose; Eckhoff, Anthony; Medelius, Pedro

2004-01-01

Signal conditioners embodying advanced concepts in analog and digital electronic circuitry and software have been developed for use in data-acquisition systems that are required to be compact and lightweight, to utilize electric energy efficiently, and to operate with high reliability, high accuracy, and high power efficiency, without intervention by human technicians. These signal conditioners were originally intended for use aboard spacecraft. There are also numerous potential terrestrial uses - especially in the fields of aeronautics and medicine, wherein it is necessary to monitor critical functions. Going beyond the usual analog and digital signal-processing functions of prior signal conditioners, the new signal conditioner performs the following additional functions: It continuously diagnoses its own electronic circuitry, so that it can detect failures and repair itself (as described below) within seconds. It continuously calibrates itself on the basis of a highly accurate and stable voltage reference, so that it can continue to generate accurate measurement data, even under extreme environmental conditions. It repairs itself in the sense that it contains a micro-controller that reroutes signals among redundant components as needed to maintain the ability to perform accurate and stable measurements. It detects deterioration of components, predicts future failures, and/or detects imminent failures by means of a real-time analysis in which, among other things, data on its present state are continuously compared with locally stored historical data. It minimizes unnecessary consumption of electric energy. The design architecture divides the signal conditioner into three main sections: an analog signal section, a digital module, and a power-management section. The design of the analog signal section does not follow the traditional approach of ensuring reliability through total redundancy of hardware: Instead, following an approach called spare parts tool box, the reliability of each component is assessed in terms of such considerations as risks of damage, mean times between failures, and the effects of certain failures on the performance of the signal conditioner as a whole system. Then, fewer or more spares are assigned for each affected component, pursuant to the results of this analysis, in order to obtain the required degree of reliability of the signal conditioner as a whole system. The digital module comprises one or more processors and field-programmable gate arrays, the number of each depending on the results of the aforementioned analysis. The digital module provides redundant control, monitoring, and processing of several analog signals. It is designed to minimize unnecessary consumption of electric energy, including, when possible, going into a low-power "sleep" mode that is implemented in firmware. The digital module communicates with external equipment via a personal-computer serial port. The digital module monitors the "health" of the rest of the signal conditioner by processing defined measurements and/or trends. It automatically makes adjustments to respond to channel failures, compensate for effects of temperature, and maintain calibration.

Implementation of AN Unmanned Aerial Vehicle System for Large Scale Mapping

NASA Astrophysics Data System (ADS)

Mah, S. B.; Cryderman, C. S.

2015-08-01

Unmanned Aerial Vehicles (UAVs), digital cameras, powerful personal computers, and software have made it possible for geomatics professionals to capture aerial photographs and generate digital terrain models and orthophotographs without using full scale aircraft or hiring mapping professionals. This has been made possible by the availability of miniaturized computers and sensors, and software which has been driven, in part, by the demand for this technology in consumer items such as smartphones. The other force that is in play is the increasing number of Do-It-Yourself (DIY) people who are building UAVs as a hobby or for professional use. Building a UAV system for mapping is an alternative to purchasing a turnkey system. This paper describes factors to be considered when building a UAV mapping system, the choices made, and the test results of a project using this completed system.

Application of digital computer APU modeling techniques to control system design.

NASA Technical Reports Server (NTRS)

Bailey, D. A.; Burriss, W. L.

1973-01-01

Study of the required controls for a H2-O2 auxiliary power unit (APU) technology program for the Space Shuttle. A steady-state system digital computer program was prepared and used to optimize initial system design. Analytical models of each system component were included. The program was used to solve a nineteen-dimensional problem, and then time-dependent differential equations were added to the computer program to simulate transient APU system and control. Some system parameters were considered quasi-steady-state, and others were treated as differential variables. The dynamic control analysis proceeded from initial ideal control modeling (which considered one control function and assumed the others to be ideal), stepwise through the system (adding control functions), until all of the control functions and their interactions were considered. In this way, the adequacy of the final control design over the required wide range of APU operating conditions was established.

LED instrument approach instruction display

NASA Technical Reports Server (NTRS)

Meredith, B. D.; Kelly, W. L., IV; Crouch, R. K.

1979-01-01

A display employing light emitting diodes (LED's) was developed to demonstrate the feasibility of such displays for presenting landing and navigation information to reduce the workload of general aviation pilots during IFR flight. The display consists of a paper tape reader, digital memory, control electronics, digital latches, and LED alphanumeric displays. A presentable digital countdown clock-timer is included as part of the system to provide a convenient means of monitoring time intervals for precise flight navigation. The system is a limited capability prototype assembled to test pilot reaction to such a device under simulated IFR operation. Pilot opinion indicates that the display is helpful in reducing the IFR pilots workload when used with a runway approach plate. However, the development of a compact, low power second generation display was recommended which could present several instructions simultaneously and provide information update capability. A microprocessor-based display could fulfill these requirements.

Geo-referenced digital data acquisition and processing system using LiDAR technology : executive summary report.

DOT National Transportation Integrated Search

2006-02-01

Problem: State-of-the-art airborne mapping is in major : transition, which affects both the data acquisition and : data processing technologies. The IT age has brought : powerful sensors and revolutionary new techniques to : acquire spatial data in l...

Digital Technologies Jump Start Telemedicine

ERIC Educational Resources Information Center

Pierce, Alan

2011-01-01

The technologists, research doctors, computer programmers, electrical engineers, and biomedical engineers who design and create new medical diagnostic equipment and medical treatments are now working on medical systems that use the computing power of personal computers and cell phones. For disease diagnosis, they are finding ways to shrink…

Lunar Pole Illumination and Communications Statistics Computed from GSSR Elevation Data

NASA Technical Reports Server (NTRS)

Bryant, Scott

2010-01-01

The Goldstone Solar System RADAR (GSSR) group at JPL produced a Digital Elevation Model (DEM) of the lunar south pole using data obtained in 2006. This model has 40-meter horizontal resolution and about 5-meter relative vertical accuracy. This paper uses that Digital Elevation Model to compute average solar illumination and Earth visibility near the lunar south pole. This data quantifies solar power and Earth communications resources at proposed lunar base locations. The elevation data were converted into local terrain horizon masks, then converted into selenographic latitude and longitude coordinates. The horizon masks were compared to latitude, longitude regions bounding the maximum Sun and Earth motions relative to the moon. Proposed lunar south pole base sites were examined in detail, with the best site showing multi-year averages of solar power availability of 92% and Direct-To-Earth (DTE) communication availability of about 50%. Results are compared with a theoretical model, and with actual sun and Earth visibility averaged over the years 2009 to 2028. Results for the lunar North pole were computed using the GSSR DEM of the lunar North pole produced in 1997. The paper also explores using a heliostat to reduce the photovoltaic power system mass and complexity.

10.2% power conversion efficiency polymer tandem solar cells consisting of two identical sub-cells.

PubMed

You, Jingbi; Chen, Chun-Chao; Hong, Ziruo; Yoshimura, Ken; Ohya, Kenichiro; Xu, Run; Ye, Shenglin; Gao, Jing; Li, Gang; Yang, Yang

2013-08-07

Polymer tandem solar cells with 10.2% power conversion efficiency are demonstrated via stacking two PDTP-DFBT:PC₇₁ BM bulk heterojunctions, connected by MoO₃/PEDOT:PSS/ZnO as an interconnecting layer. The tandem solar cells increase the power conversion efficiency of the PDTP-DFBT:PC₇₁ BM system from 8.1% to 10.2%, successfully demonstrating polymer tandem solar cells with identical sub-cells of double-digit efficiency. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The Use of Field Programmable Gate Arrays (FPGA) in Small Satellite Communication Systems

NASA Technical Reports Server (NTRS)

Varnavas, Kosta; Sims, William Herbert; Casas, Joseph

2015-01-01

This paper will describe the use of digital Field Programmable Gate Arrays (FPGA) to contribute to advancing the state-of-the-art in software defined radio (SDR) transponder design for the emerging SmallSat and CubeSat industry and to provide advances for NASA as described in the TAO5 Communication and Navigation Roadmap (Ref 4). The use of software defined radios (SDR) has been around for a long time. A typical implementation of the SDR is to use a processor and write software to implement all the functions of filtering, carrier recovery, error correction, framing etc. Even with modern high speed and low power digital signal processors, high speed memories, and efficient coding, the compute intensive nature of digital filters, error correcting and other algorithms is too much for modern processors to get efficient use of the available bandwidth to the ground. By using FPGAs, these compute intensive tasks can be done in parallel, pipelined fashion and more efficiently use every clock cycle to significantly increase throughput while maintaining low power. These methods will implement digital radios with significant data rates in the X and Ka bands. Using these state-of-the-art technologies, unprecedented uplink and downlink capabilities can be achieved in a 1/2 U sized telemetry system. Additionally, modern FPGAs have embedded processing systems, such as ARM cores, integrated inside the FPGA allowing mundane tasks such as parameter commanding to occur easily and flexibly. Potential partners include other NASA centers, industry and the DOD. These assets are associated with small satellite demonstration flights, LEO and deep space applications. MSFC currently has an SDR transponder test-bed using Hardware-in-the-Loop techniques to evaluate and improve SDR technologies.

Construction of a Cyber Attack Model for Nuclear Power Plants

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

Varuttamaseni, Athi; Bari, Robert A.; Youngblood, Robert

The consideration of how one compromised digital equipment can impact neighboring equipment is critical to understanding the progression of cyber attacks. The degree of influence that one component may have on another depends on a variety of factors, including the sharing of resources such as network bandwidth or processing power, the level of trust between components, and the inclusion of segmentation devices such as firewalls. The interactions among components via mechanisms that are unique to the digital world are not usually considered in traditional PRA. This means potential sequences of events that may occur during an attack may be missedmore » if one were to only look at conventional accident sequences. This paper presents a method where, starting from the initial attack vector, the progression of a cyber attack can be modeled. The propagation of the attack is modeled by considering certain attributes of the digital components in the system. These attributes determine the potential vulnerability of a component to a class of attack and the capability gained by the attackers once they are in control of the equipment. The use of attributes allows similar components (components with the same set of attributes) to be modeled in the same way, thereby reducing the computing resources required for analysis of large systems.« less

A "Social Bitcoin" could sustain a democratic digital world

NASA Astrophysics Data System (ADS)

Kleineberg, Kaj-Kolja; Helbing, Dirk

2016-12-01

A multidimensional financial system could provide benefits for individuals, companies, and states. Instead of top-down control, which is destined to eventually fail in a hyperconnected world, a bottom-up creation of value can unleash creative potential and drive innovations. Multiple currency dimensions can represent different externalities and thus enable the design of incentives and feedback mechanisms that foster the ability of complex dynamical systems to self-organize and lead to a more resilient society and sustainable economy. Modern information and communication technologies play a crucial role in this process, as Web 2.0 and online social networks promote cooperation and collaboration on unprecedented scales. Within this contribution, we discuss how one dimension of a multidimensional currency system could represent socio-digital capital (Social Bitcoins) that can be generated in a bottom-up way by individuals who perform search and navigation tasks in a future version of the digital world. The incentive to mine Social Bitcoins could sustain digital diversity, which mitigates the risk of totalitarian control by powerful monopolies of information and can create new business opportunities needed in times where a large fraction of current jobs is estimated to disappear due to computerisation.

Erbium/ytterbium co-doped double clad fiber amplifier, its applications and effects in fiber optic communication systems

NASA Astrophysics Data System (ADS)

Dua, Puneit

Increased demand for larger bandwidth and longer inter-amplifiers distances translates to higher power budgets for fiber optic communication systems in order to overcome large splitting losses and achieve acceptable signal-to-noise ratios. Due to their unique design ytterbium sensitized erbium doped, double clad fiber amplifiers; offer significant increase in the output powers that can be obtained. In this thesis we investigate, a one-stage, high power erbium and ytterbium co-doped double clad fiber amplifier (DCFA) with output power of 1.4W, designed and built in our lab. Experimental demonstration and numerical simulation techniques have been used to systematically study the applications of such an amplifier and the effects of incorporating it in various fiber optic communication systems. Amplitude modulated subcarrier multiplexed (AM-SCM) CATV distribution experiment has been performed to verify the feasibility of using this amplifier in an analog/digital communication system. The applications of the amplifier as a Fabry-Perot and ring fiber laser with an all-fiber cavity, a broadband supercontinuum source and for generation of high power, short pulses at 5GHz have been experimentally demonstrated. A variety of observable nonlinear effects occur due to the high intensity of the optical powers confined in micron-sized cores of the fibers, this thesis explores in detail some of these effects caused by using the high power Er/Yb double clad fiber amplifier. A fiber optic based analog/digital CATV system experiences composite second order (CSO) distortion due to the interaction between the gain tilt---the variation of gain with wavelength, of the doped fiber amplifier and the wavelength chirp of the directly modulated semiconductor laser. Gain tilt of the Er/Yb co-doped fiber amplifier has been experimentally measured and its contribution to the CSO of the system calculated. Theoretical analysis of a wavelength division multiplexed system with closely spaced channels has been carried out to show that crosstalk can occur due to the four-wave mixing products generated inside the high power Er/Yb DCFA. A model for parametric amplification due to four-wave mixing has been developed and used to analyze its application for short pulse generation and high speed optical time division multiplexing.

Magnetics and Power System Upgrades for the Pegasus-U Experiment

NASA Astrophysics Data System (ADS)

Preston, R. C.; Bongard, M. W.; Fonck, R. J.; Lewicki, B. T.

2014-10-01

To support the missions of developing local helicity injection startup and exploiting advanced tokamak physics studies at near unity aspect ratio, the proposed Pegasus-U will include expanded magnetic systems and associated power supplies. A new centerstack increases the toroidal field seven times to 1 T and the volt-seconds by a factor of six while maintaining operation at an aspect ratio of 1.2. The poloidal field magnet system is expanded to support improved shape control and robust double or single null divertor operation at the full plasma current of 0.3 MA. An integrated digital control system based on Field Programmable Gate Arrays (FPGAs) provides active feedback control of all magnet currents. Implementation of the FPGAs is achieved with modular noise reducing electronics. The digital feedback controllers replace the existing analog systems and switch multiplexing technology. This will reduce noise sensitivity and allow the operational Ohmic power supply voltage to increase from 2100 V to its maximum capacity of 2400 V. The feedback controller replacement also allows frequency control for ``freewheeling''--stopping the switching for a short interval and allowing the current to coast. The FPGAs assist in optimizing pulse length by having programmable switching events to minimize energy losses. They also allow for more efficient switching topologies that provide improved stored energy utilization, and support increasing the pulse length from 25 ms to 50-100 ms. Work supported by US DOE Grant DE-FG02-96ER54375.

Preliminary design study of a higher harmonic blade feathering control system

NASA Technical Reports Server (NTRS)

Powers, R. W.

1980-01-01

The feasibility to incorporate an active higher harmonic control (HHC) system on an OH-6A rotorcraft was demonstrated. The introduction of continuously modulated low amplitude 4P feathering showed potential for reducing rotor transmitted oscillatory loads. The design implementation of this system on a baseline OH-6A required generation of a hydraulic power system, control actuator placement and design integration of an electronic subsystem comprised of an electronic control unit (ECU) and digital microcomputer. Various placements of the HHC actuators in the primary control system are evaluated. Assembly drawings of the actuator concepts and control rigging are presented. The advantages of generating both hydraulic power and 4F control motions in the nonrotating system is confirmed.

Simulation of demand-response power management in smart city

NASA Astrophysics Data System (ADS)

Kadam, Kshitija

Smart Grids manage energy efficiently through intelligent monitoring and control of all the components connected to the electrical grid. Advanced digital technology, combined with sensors and power electronics, can greatly improve transmission line efficiency. This thesis proposed a model of a deregulated grid which supplied power to diverse set of consumers and allowed them to participate in decision making process through two-way communication. The deregulated market encourages competition at the generation and distribution levels through communication with the central system operator. A software platform was developed and executed to manage the communication, as well for energy management of the overall system. It also demonstrated self-healing property of the system in case a fault occurs, resulting in an outage. The system not only recovered from the fault but managed to do so in a short time with no/minimum human involvement.

Enabling MPEG-2 video playback in embedded systems through improved data cache efficiency

NASA Astrophysics Data System (ADS)

Soderquist, Peter; Leeser, Miriam E.

1999-01-01

Digital video decoding, enabled by the MPEG-2 Video standard, is an important future application for embedded systems, particularly PDAs and other information appliances. Many such system require portability and wireless communication capabilities, and thus face severe limitations in size and power consumption. This places a premium on integration and efficiency, and favors software solutions for video functionality over specialized hardware. The processors in most embedded system currently lack the computational power needed to perform video decoding, but a related and equally important problem is the required data bandwidth, and the need to cost-effectively insure adequate data supply. MPEG data sets are very large, and generate significant amounts of excess memory traffic for standard data caches, up to 100 times the amount required for decoding. Meanwhile, cost and power limitations restrict cache sizes in embedded systems. Some systems, including many media processors, eliminate caches in favor of memories under direct, painstaking software control in the manner of digital signal processors. Yet MPEG data has locality which caches can exploit if properly optimized, providing fast, flexible, and automatic data supply. We propose a set of enhancements which target the specific needs of the heterogeneous types within the MPEG decoder working set. These optimizations significantly improve the efficiency of small caches, reducing cache-memory traffic by almost 70 percent, and can make an enhanced 4 KB cache perform better than a standard 1 MB cache. This performance improvement can enable high-resolution, full frame rate video playback in cheaper, smaller system than woudl otherwise be possible.

Development of high precision digital driver of acoustic-optical frequency shifter for ROG

NASA Astrophysics Data System (ADS)

Zhang, Rong; Kong, Mei; Xu, Yameng

2016-10-01

We develop a high precision digital driver of the acoustic-optical frequency shifter (AOFS) based on the parallel direct digital synthesizer (DDS) technology. We use an atomic clock as the phase-locked loop (PLL) reference clock, and the PLL is realized by a dual digital phase-locked loop. A DDS sampling clock up to 320 MHz with a frequency stability as low as 10-12 Hz is obtained. By constructing the RF signal measurement system, it is measured that the frequency output range of the AOFS-driver is 52-58 MHz, the center frequency of the band-pass filter is 55 MHz, the ripple in the band is less than 1 dB@3MHz, the single channel output power is up to 0.3 W, the frequency stability is 1 ppb (1 hour duration), and the frequency-shift precision is 0.1 Hz. The obtained frequency stability has two orders of improvement compared to that of the analog AOFS-drivers. For the designed binary frequency shift keying (2-FSK) and binary phase shift keying (2-PSK) modulation system, the demodulating frequency of the input TTL synchronous level signal is up to 10 kHz. The designed digital-bus coding/decoding system is compatible with many conventional digital bus protocols. It can interface with the ROG signal detecting software through the integrated drive electronics (IDE) and exchange data with the two DDS frequency-shift channels through the signal detecting software.

Adjustable Nyquist-rate System for Single-Bit Sigma-Delta ADC with Alternative FIR Architecture

NASA Astrophysics Data System (ADS)

Frick, Vincent; Dadouche, Foudil; Berviller, Hervé

2016-09-01

This paper presents a new smart and compact system dedicated to control the output sampling frequency of an analogue-to-digital converters (ADC) based on single-bit sigma-delta (ΣΔ) modulator. This system dramatically improves the spectral analysis capabilities of power network analysers (power meters) by adjusting the ADC's sampling frequency to the input signal's fundamental frequency with a few parts per million accuracy. The trade-off between straightforwardness and performance that motivated the choice of the ADC's architecture are preliminary discussed. It particularly comes along with design considerations of an ultra-steep direct-form FIR that is optimised in terms of size and operating speed. Thanks to compact standard VHDL language description, the architecture of the proposed system is particularly suitable for application-specific integrated circuit (ASIC) implementation-oriented low-power and low-cost power meter applications. Field programmable gate array (FPGA) prototyping and experimental results validate the adjustable sampling frequency concept. They also show that the system can perform better in terms of implementation and power capabilities compared to dedicated IP resources.

Analyzing long-term changes in vegetation with geographic information system and remotely sensed data

Treesearch

Louis. R. Iverson; Paul. G. Risser; Paul. G. Risser

1987-01-01

Geographic information systems and remote sensing techniques are powerful tools in the analysis of long-term changes in vegetation and land use, especially because spatial information from two or more time intervals can be compared more readily than by manual methods. A primary restriction is the paucity of data that has been digitized from earlier periods. The...

Proceedings of the ADPA/AIAA/ASME/SPIE Conference on Active and Adaptive Structures Held in Alexandria, Virginia on November 4 - 8, 1991

DTIC Science & Technology

1991-11-08

saturation limit. The control action is sent via a digital-to-analog converter to a power amplifier to activate the NITINOL fibers embedded inside the...feedback approaches in the design of a modal- eiipl.’ i,, n e .ti )tal filters with feedfor.ard and feedback based active control system. There are...photocells; and a series of narrow bandpass filters with silicon photodetectors. The sensor outputs are fed through an anolog to digital converter into the

Physics and engineering aspects of cell and tissue imaging systems: microscopic devices and computer assisted diagnosis.

PubMed

Chen, Xiaodong; Ren, Liqiang; Zheng, Bin; Liu, Hong

2013-01-01

The conventional optical microscopes have been used widely in scientific research and in clinical practice. The modern digital microscopic devices combine the power of optical imaging and computerized analysis, archiving and communication techniques. It has a great potential in pathological examinations for improving the efficiency and accuracy of clinical diagnosis. This chapter reviews the basic optical principles of conventional microscopes, fluorescence microscopes and electron microscopes. The recent developments and future clinical applications of advanced digital microscopic imaging methods and computer assisted diagnosis schemes are also discussed.

Simplified APC for Space Shuttle applications. [Adaptive Predictive Coding for speech transmission

NASA Technical Reports Server (NTRS)

Hutchins, S. E.; Batson, B. H.

1975-01-01

This paper describes an 8 kbps adaptive predictive digital speech transmission system which was designed for potential use in the Space Shuttle Program. The system was designed to provide good voice quality in the presence of both cabin noise on board the Shuttle and the anticipated bursty channel. Minimal increase in size, weight, and power over the current high data rate system was also a design objective.

DRS: Derivational Reasoning System

NASA Technical Reports Server (NTRS)

Bose, Bhaskar

1995-01-01

The high reliability requirements for airborne systems requires fault-tolerant architectures to address failures in the presence of physical faults, and the elimination of design flaws during the specification and validation phase of the design cycle. Although much progress has been made in developing methods to address physical faults, design flaws remain a serious problem. Formal methods provides a mathematical basis for removing design flaws from digital systems. DRS (Derivational Reasoning System) is a formal design tool based on advanced research in mathematical modeling and formal synthesis. The system implements a basic design algebra for synthesizing digital circuit descriptions from high level functional specifications. DRS incorporates an executable specification language, a set of correctness preserving transformations, verification interface, and a logic synthesis interface, making it a powerful tool for realizing hardware from abstract specifications. DRS integrates recent advances in transformational reasoning, automated theorem proving and high-level CAD synthesis systems in order to provide enhanced reliability in designs with reduced time and cost.

Memristive Mixed-Signal Neuromorphic Systems: Energy-Efficient Learning at the Circuit-Level

DOE PAGES

Chakma, Gangotree; Adnan, Md Musabbir; Wyer, Austin R.; ...

2017-11-23

Neuromorphic computing is non-von Neumann computer architecture for the post Moore’s law era of computing. Since a main focus of the post Moore’s law era is energy-efficient computing with fewer resources and less area, neuromorphic computing contributes effectively in this research. Here in this paper, we present a memristive neuromorphic system for improved power and area efficiency. Our particular mixed-signal approach implements neural networks with spiking events in a synchronous way. Moreover, the use of nano-scale memristive devices saves both area and power in the system. We also provide device-level considerations that make the system more energy-efficient. The proposed systemmore » additionally includes synchronous digital long term plasticity, an online learning methodology that helps the system train the neural networks during the operation phase and improves the efficiency in learning considering the power consumption and area overhead.« less

Memristive Mixed-Signal Neuromorphic Systems: Energy-Efficient Learning at the Circuit-Level

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

Chakma, Gangotree; Adnan, Md Musabbir; Wyer, Austin R.

Neuromorphic computing is non-von Neumann computer architecture for the post Moore’s law era of computing. Since a main focus of the post Moore’s law era is energy-efficient computing with fewer resources and less area, neuromorphic computing contributes effectively in this research. Here in this paper, we present a memristive neuromorphic system for improved power and area efficiency. Our particular mixed-signal approach implements neural networks with spiking events in a synchronous way. Moreover, the use of nano-scale memristive devices saves both area and power in the system. We also provide device-level considerations that make the system more energy-efficient. The proposed systemmore » additionally includes synchronous digital long term plasticity, an online learning methodology that helps the system train the neural networks during the operation phase and improves the efficiency in learning considering the power consumption and area overhead.« less

Integration of plug-in hybrid electric vehicles (PHEV) with grid connected residential photovoltaic energy systems

NASA Astrophysics Data System (ADS)

Nagarajan, Adarsh; Shireen, Wajiha

2013-06-01

This paper proposes an approach for integrating Plug-In Hybrid Electric Vehicles (PHEV) to an existing residential photovoltaic system, to control and optimize the power consumption of residential load. Control involves determining the source from which residential load will be catered, where as optimization of power flow reduces the stress on the grid. The system built to achieve the goal is a combination of the existing residential photovoltaic system, PHEV, Power Conditioning Unit (PCU), and a controller. The PCU involves two DC-DC Boost Converters and an inverter. This paper emphasizes on developing the controller logic and its implementation in order to accommodate the flexibility and benefits of the proposed integrated system. The proposed controller logic has been simulated using MATLAB SIMULINK and further implemented using Digital Signal Processor (DSP) microcontroller, TMS320F28035, from Texas Instruments

Control strategy based on SPWM switching patterns for grid connected photovoltaic inverter

NASA Astrophysics Data System (ADS)

Hassaine, L.; Mraoui, A.

2017-02-01

Generally, for lower installation of photovoltaic systems connected to the grid, pulse width modulation (PWM) is a widely used technique for controlling the voltage source inverters injects currents into the grid. The current injected must be sinusoidal with reduced harmonic distortion. In this paper, a digital implementation of a control strategy based on PWM switching patterns for an inverter for photovoltaic system connected to the grid is presented. This strategy synchronize a sinusoidal inverter output current with a grid voltage The digital implementation of the proposed PWM switching pattern when is compared with the conventional one exhibit the advantage: Simplicity, reduction of the memory requirements and power calculation for the control

Processing techniques for digital sonar images from GLORIA.

USGS Publications Warehouse

Chavez, P.S.

1986-01-01

Image processing techniques have been developed to handle data from one of the newest members of the remote sensing family of digital imaging systems. This paper discusses software to process data collected by the GLORIA (Geological Long Range Inclined Asdic) sonar imaging system, designed and built by the Institute of Oceanographic Sciences (IOS) in England, to correct for both geometric and radiometric distortions that exist in the original 'raw' data. Preprocessing algorithms that are GLORIA-specific include corrections for slant-range geometry, water column offset, aspect ratio distortion, changes in the ship's velocity, speckle noise, and shading problems caused by the power drop-off which occurs as a function of range.-from Author

Step-by-Step Design of an FPGA-Based Digital Compensator for DC/DC Converters Oriented to an Introductory Course

ERIC Educational Resources Information Center

Zumel, P.; Fernandez, C.; Sanz, M.; Lazaro, A.; Barrado, A.

2011-01-01

In this paper, a short introductory course to introduce field-programmable gate array (FPGA)-based digital control of dc/dc switching power converters is presented. Digital control based on specific hardware has been at the leading edge of low-medium power dc/dc switching converters in recent years. Besides industry's interest in this topic, from…

75 FR 17874 - Digital Audio Broadcasting Systems and Their Impact on the Terrestrial Radio Broadcast Service

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-08

... power (ERP), and implements interference mitigation and remediation procedures to resolve promptly..., and the interference mitigation and remediation procedures will make certain that permissible... ERP to more than 4% of authorized analog ERP. 4. Establishes interference remediation procedures that...

SU-G-IeP3-11: On the Utility of Pixel Variance to Characterize Noise for Image Receptors of Digital Radiography Systems

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

Finley, C; Dave, J

Purpose: To characterize noise for image receptors of digital radiography systems based on pixel variance. Methods: Nine calibrated digital image receptors associated with nine new portable digital radiography systems (Carestream Health, Inc., Rochester, NY) were used in this study. For each image receptor, thirteen images were acquired with RQA5 beam conditions for input detector air kerma ranging from 0 to 110 µGy, and linearized ‘For Processing’ images were extracted. Mean pixel value (MPV), standard deviation (SD) and relative noise (SD/MPV) were obtained from each image using ROI sizes varying from 2.5×2.5 to 20×20 mm{sup 2}. Variance (SD{sup 2}) was plottedmore » as a function of input detector air kerma and the coefficients of the quadratic fit were used to derive structured, quantum and electronic noise coefficients. Relative noise was also fitted as a function of input detector air kerma to identify noise sources. The fitting functions used least-squares approach. Results: The coefficient of variation values obtained using different ROI sizes was less than 1% for all the images. The structured, quantum and electronic coefficients obtained from the quadratic fit of variance (r>0.97) were 0.43±0.10, 3.95±0.27 and 2.89±0.74 (mean ± standard deviation), respectively, indicating that overall the quantum noise was the dominant noise source. However, for one system electronic noise coefficient (3.91) was greater than quantum noise coefficient (3.56) indicating electronic noise to be dominant. Using relative noise values, the power parameter of the fitting equation (|r|>0.93) showed a mean and standard deviation of 0.46±0.02. A 0.50 value for this power parameter indicates quantum noise to be the dominant noise source whereas values around 0.50 indicate presence of other noise sources. Conclusion: Characterizing noise from pixel variance assists in identifying contributions from various noise sources that, eventually, may affect image quality. This approach may be integrated during periodic quality assessments of digital image receptors.« less

Digital slip frequency generator and method for determining the desired slip frequency

DOEpatents

Klein, Frederick F.

1989-01-01

The output frequency of an electric power generator is kept constant with variable rotor speed by automatic adjustment of the excitation slip frequency. The invention features a digital slip frequency generator which provides sine and cosine waveforms from a look-up table, which are combined with real and reactive power output of the power generator.