Science.gov

Sample records for coding circuits

  1. Electrical Circuit Simulation Code

    SciTech Connect

    Wix, Steven D.; Waters, Arlon J.; Shirley, David

    2001-08-09

    Massively-Parallel Electrical Circuit Simulation Code. CHILESPICE is a massively-arallel distributed-memory electrical circuit simulation tool that contains many enhanced radiation, time-based, and thermal features and models. Large scale electronic circuit simulation. Shared memory, parallel processing, enhance convergence. Sandia specific device models.

  2. Compact, Flexible Telemetry-Coding Circuits

    NASA Technical Reports Server (NTRS)

    Katz, Richard B.; Tooley, Matthew; Settles, Beverly

    1993-01-01

    Circuits encoding binary telemetry data designed to synthesize any number of selectable codes. Designed for use aboard spacecraft, with features also making them attractive for terrestrial applications: Simple and compact relative to prior coding circuits, built with commercial integrated circuits, and incorporate protective redundancy. Output distortions minimized, and spurious attenuated and/or abbreviated output pulses eliminated.

  3. Electromagnetic Gun Circuit Analysis Code (EGCAC)

    NASA Astrophysics Data System (ADS)

    Rolader, Glenn E.; Thornhill, Lindsey D.; Batteh, Jad H.; Scanlon, James J., III

    1993-01-01

    This paper describes a system engineering code that simulates the performance of a railgun/power supply system. The code, named EGCAC (Electromagnetic Gun Circuit Analysis Code), accounts for many performance degrading effects including viscous drag on the armature, viscous drag on the gas being pushed in front of the projectile, entrained gas that must be accelerated in front of the projectile, time-dependent rail resistance, armature resistance, system resistance, and ablation drag. EGCAC has been utilized to predict railgun performance up to a velocity of approximately 4 km/s for experiments at several laboratories. In this paper, the theory of EGCAC is described, and sample calculations are presented.

  4. Midbrain local circuits shape sound intensity codes.

    PubMed

    Grimsley, Calum Alex; Sanchez, Jason Tait; Sivaramakrishnan, Shobhana

    2013-01-01

    Hierarchical processing of sensory information requires interaction at multiple levels along the peripheral to central pathway. Recent evidence suggests that interaction between driving and modulating components can shape both top down and bottom up processing of sensory information. Here we show that a component inherited from extrinsic sources combines with local components to code sound intensity. By applying high concentrations of divalent cations to neurons in the nucleus of the inferior colliculus in the auditory midbrain, we show that as sound intensity increases, the source of synaptic efficacy changes from inherited inputs to local circuits. In neurons with a wide dynamic range response to intensity, inherited inputs increase firing rates at low sound intensities but saturate at mid-to-high intensities. Local circuits activate at high sound intensities and widen dynamic range by continuously increasing their output gain with intensity. Inherited inputs are necessary and sufficient to evoke tuned responses, however local circuits change peak output. Push-pull driving inhibition and excitation create net excitatory drive to intensity-variant neurons and tune neurons to intensity. Our results reveal that dynamic range and tuning re-emerge in the auditory midbrain through local circuits that are themselves variable or tuned.

  5. 49 CFR 236.727 - Circuit, track; coded.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Circuit, track; coded. 236.727 Section 236.727 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Circuit, track; coded. A track circuit in which the energy is varied or interrupted periodically....

  6. Developmental metaplasticity in neural circuit codes of firing and structure.

    PubMed

    Baram, Yoram

    2017-01-01

    Firing-rate dynamics have been hypothesized to mediate inter-neural information transfer in the brain. While the Hebbian paradigm, relating learning and memory to firing activity, has put synaptic efficacy variation at the center of cortical plasticity, we suggest that the external expression of plasticity by changes in the firing-rate dynamics represents a more general notion of plasticity. Hypothesizing that time constants of plasticity and firing dynamics increase with age, and employing the filtering property of the neuron, we obtain the elementary code of global attractors associated with the firing-rate dynamics in each developmental stage. We define a neural circuit connectivity code as an indivisible set of circuit structures generated by membrane and synapse activation and silencing. Synchronous firing patterns under parameter uniformity, and asynchronous circuit firing are shown to be driven, respectively, by membrane and synapse silencing and reactivation, and maintained by the neuronal filtering property. Analytic, graphical and simulation representation of the discrete iteration maps and of the global attractor codes of neural firing rate are found to be consistent with previous empirical neurobiological findings, which have lacked, however, a specific correspondence between firing modes, time constants, circuit connectivity and cortical developmental stages.

  7. User`s guide and physics manual for the SCATPlus circuit code

    SciTech Connect

    Yapuncich, M.L.; Deninger, W.J.; Gribble, R.F.

    1994-05-09

    ScatPlus is a user friendly circuit code and an expandable library of circuit models for electrical components and devices; it can be used to predict the transient behavior in electric circuits. The heart of ScatPlus is the transient circuit solver SCAT written in 1986 by R.F. Gribble. This manual includes system requirements, physics manual, ScatPlus component library, tutorial, ScatPlus screen, menus and toolbar, ScatPlus tool bar, procedures.

  8. Quantum circuit for optimal eavesdropping in quantum key distribution using phase-time coding

    SciTech Connect

    Kronberg, D. A.; Molotkov, S. N.

    2010-07-15

    A quantum circuit is constructed for optimal eavesdropping on quantum key distribution proto- cols using phase-time coding, and its physical implementation based on linear and nonlinear fiber-optic components is proposed.

  9. A direct sequence spread spectrum code acquisition circuit for wireless sensor networks

    NASA Astrophysics Data System (ADS)

    Ghaisari, Jafar; Ferdosi, Arash

    2011-06-01

    Narrow band (NB), spread spectrum (SS), and ultra wide band (UWB) are three physical layer bandwidth types used in wireless sensor networks (WSN). SS and UWB technologies have many advantages over NB, which make them preferable for WSN. Synchronisation of different nodes in a WSN is an important task that is necessary to improve cooperation and lifetime of nodes. Code acquisition is the main step of a node's time synchronisation. In this article, a pseudo noise code generator and a code acquisition circuit are proposed, designed and tested using direct sequence SS technique. To investigate the properties of the designed circuits, simulations are carried out via Xilinx Foundation Series software in the real mode. The results demonstrate excellent performance of the proposed algorithms and circuits in all realistic conditions. The code acquisition circuit proposed an adaptive testing window for single dwell serial search method. The code acquisition circuit is a clock phase free approach, thus the clock coherency step is cancelled. Moreover, clock phase difference between transmitter and receiver nodes does not mostly affect the acquisition and thus synchronisation time.

  10. Direction-selective circuits shape noise to ensure a precise population code

    PubMed Central

    Zylberberg, Joel; Cafaro, Jon; Turner, Maxwell H

    2016-01-01

    Summary Neural responses are noisy, and circuit structure can correlate this noise across neurons. Theoretical studies show that noise correlations can have diverse effects on population coding, but these studies rarely explore stimulus dependence of noise correlations. Here, we show that noise correlations in responses of ON-OFF direction-selective retinal ganglion cells are strongly stimulus dependent and we uncover the circuit mechanisms producing this stimulus dependence. A population model based on these mechanistic studies shows that stimulus-dependent noise correlations improve the encoding of motion direction two-fold compared to independent noise. This work demonstrates a mechanism by which a neural circuit effectively shapes its signal and noise in concert, minimizing corruption of signal by noise. Finally, we generalize our findings beyond direction coding in the retina and show that stimulus-dependent correlations will generally enhance information coding in populations of diversely tuned neurons. PMID:26796691

  11. BERTHA: A versatile transmission line and circuit code

    NASA Astrophysics Data System (ADS)

    Hinshelwood, D. D.

    1983-11-01

    An improved version of the NRL transmission line code of W. H. Lupton is presented. The capabilities of the original program were extended to allow magnetically insulated transmission lines, plasma opening switches, imploding plasma loads and discrete element electrical networks, for example, to be modeled. BERTHA is used to simulate any system that is represented by a configuration of transmission line elements. The electrical behavior of the system is calculated by repeatedly summing the reflected and transmitted waves at the ends of each element. This program is versatile, easy to use and easily implemented on desktop microcomputers.

  12. Development of a numerical computer code and circuit element models for simulation of firing systems

    SciTech Connect

    Carpenter, K.H. . Dept. of Electrical and Computer Engineering)

    1990-07-02

    Numerical simulation of firing systems requires both the appropriate circuit analysis framework and the special element models required by the application. We have modified the SPICE circuit analysis code (version 2G.6), developed originally at the Electronic Research Laboratory of the University of California, Berkeley, to allow it to be used on MSDOS-based, personal computers and to give it two additional circuit elements needed by firing systems--fuses and saturating inductances. An interactive editor and a batch driver have been written to ease the use of the SPICE program by system designers, and the interactive graphical post processor, NUTMEG, supplied by U. C. Berkeley with SPICE version 3B1, has been interfaced to the output from the modified SPICE. Documentation and installation aids have been provided to make the total software system accessible to PC users. Sample problems show that the resulting code is in agreement with the FIRESET code on which the fuse model was based (with some modifications to the dynamics of scaling fuse parameters). In order to allow for more complex simulations of firing systems, studies have been made of additional special circuit elements--switches and ferrite cored inductances. A simple switch model has been investigated which promises to give at least a first approximation to the physical effects of a non ideal switch, and which can be added to the existing SPICE circuits without changing the SPICE code itself. The effect of fast rise time pulses on ferrites has been studied experimentally in order to provide a base for future modeling and incorporation of the dynamic effects of changes in core magnetization into the SPICE code. This report contains detailed accounts of the work on these topics performed during the period it covers, and has appendices listing all source code written documentation produced.

  13. SPOCK: A SPICE based circuit code for modeling pulsed power machines

    SciTech Connect

    Ingermanson, R.; Parks, D.

    1996-12-31

    SPICE is an industry standard electrical circuit simulation code developed by the University of California at Berkeley over the last twenty years. The authors have developed a number of new SPICE devices of interest to the pulsed power community: plasma opening switches, plasma radiation sources, bremsstrahlung diodes, magnetically insulated transmission lines, explosively driven flux compressors. These new devices are integrated into SPICE using S-Cubed`s MIRIAD technology to create a user-friendly circuit code that runs on Unix workstations or under Windows NT or Windows 95. The new circuit code is called SPOCK--``S-Cubed Power Optimizing Circuit Kit.`` SPOCK allows the user to easily run optimization studies by setting up runs in which any circuit parameters can be systematically varied. Results can be plotted as 1-D line plots, 2-D contour plots, or 3-D ``bedsheet`` plots. The authors demonstrate SPOCK`s capabilities on a color laptop computer, performing realtime analysis of typical configurations of such machines as HAWK and ACE4.

  14. Application of Error Correcting Codes in Fault-Tolerant Logic Design for VLSI Circuits

    DTIC Science & Technology

    1992-08-14

    Difference between par Erroneous bit( s ) expected and actual (do) (unidirectional) residue(dr) 8(5) 0 d7d6 10 (3) 0 d5d4 3( 10 ) 0 d4d3 4(9) 0 d2dl 9(4) 0...indicating the presence of the s -on transistor. Since C for any fault, the circuit never produces an incorrect code word i.e. 10 instead of 01 or vice...way that P2 82 P for any defect (break or s -on) in the circuit the outputs 1 P4 -- will assume a value of 01 or 10 . For a fault-free circuit the

  15. How Do Efficient Coding Strategies Depend on Origins of Noise in Neural Circuits?

    PubMed Central

    Shea-Brown, Eric

    2016-01-01

    Neural circuits reliably encode and transmit signals despite the presence of noise at multiple stages of processing. The efficient coding hypothesis, a guiding principle in computational neuroscience, suggests that a neuron or population of neurons allocates its limited range of responses as efficiently as possible to best encode inputs while mitigating the effects of noise. Previous work on this question relies on specific assumptions about where noise enters a circuit, limiting the generality of the resulting conclusions. Here we systematically investigate how noise introduced at different stages of neural processing impacts optimal coding strategies. Using simulations and a flexible analytical approach, we show how these strategies depend on the strength of each noise source, revealing under what conditions the different noise sources have competing or complementary effects. We draw two primary conclusions: (1) differences in encoding strategies between sensory systems—or even adaptational changes in encoding properties within a given system—may be produced by changes in the structure or location of neural noise, and (2) characterization of both circuit nonlinearities as well as noise are necessary to evaluate whether a circuit is performing efficiently. PMID:27741248

  16. A multi coding technique to reduce transition activity in VLSI circuits

    NASA Astrophysics Data System (ADS)

    Vithyalakshmi, N.; Rajaram, M.

    2014-02-01

    Advances in VLSI technology have enabled the implementation of complex digital circuits in a single chip, reducing system size and power consumption. In deep submicron low power CMOS VLSI design, the main cause of energy dissipation is charging and discharging of internal node capacitances due to transition activity. Transition activity is one of the major factors that also affect the dynamic power dissipation. This paper proposes power reduction analyzed through algorithm and logic circuit levels. In algorithm level the key aspect of reducing power dissipation is by minimizing transition activity and is achieved by introducing a data coding technique. So a novel multi coding technique is introduced to improve the efficiency of transition activity up to 52.3% on the bus lines, which will automatically reduce the dynamic power dissipation. In addition, 1 bit full adders are introduced in the Hamming distance estimator block, which reduces the device count. This coding method is implemented using Verilog HDL. The overall performance is analyzed by using Modelsim and Xilinx Tools. In total 38.2% power saving capability is achieved compared to other existing methods.

  17. Superconducting quantum circuits at the surface code threshold for fault tolerance.

    PubMed

    Barends, R; Kelly, J; Megrant, A; Veitia, A; Sank, D; Jeffrey, E; White, T C; Mutus, J; Fowler, A G; Campbell, B; Chen, Y; Chen, Z; Chiaro, B; Dunsworth, A; Neill, C; O'Malley, P; Roushan, P; Vainsencher, A; Wenner, J; Korotkov, A N; Cleland, A N; Martinis, John M

    2014-04-24

    A quantum computer can solve hard problems, such as prime factoring, database searching and quantum simulation, at the cost of needing to protect fragile quantum states from error. Quantum error correction provides this protection by distributing a logical state among many physical quantum bits (qubits) by means of quantum entanglement. Superconductivity is a useful phenomenon in this regard, because it allows the construction of large quantum circuits and is compatible with microfabrication. For superconducting qubits, the surface code approach to quantum computing is a natural choice for error correction, because it uses only nearest-neighbour coupling and rapidly cycled entangling gates. The gate fidelity requirements are modest: the per-step fidelity threshold is only about 99 per cent. Here we demonstrate a universal set of logic gates in a superconducting multi-qubit processor, achieving an average single-qubit gate fidelity of 99.92 per cent and a two-qubit gate fidelity of up to 99.4 per cent. This places Josephson quantum computing at the fault-tolerance threshold for surface code error correction. Our quantum processor is a first step towards the surface code, using five qubits arranged in a linear array with nearest-neighbour coupling. As a further demonstration, we construct a five-qubit Greenberger-Horne-Zeilinger state using the complete circuit and full set of gates. The results demonstrate that Josephson quantum computing is a high-fidelity technology, with a clear path to scaling up to large-scale, fault-tolerant quantum circuits.

  18. a Thermohydraulic-Quenching Code for Superconducting Magnets in Network Circuits

    NASA Astrophysics Data System (ADS)

    Feng, Jun; Schultz, Joel; Minervini, Joe

    2010-04-01

    A thermohydraulic-quench code "Solxport3D-Quench" has been developed for a system of superconducting and normal solenoid magnets with supply network circuits. Each power supply network circuit consists of at least one superconducting magnet with parallel circuits including voltage sources, resistors or diodes. When used for analysis of a magnetic confinement fusion device, the plasma currents and passive structure eddy currents are also included in all scenarios. The simulation starts from superconducting stage for each magnet coil. The superconducting stage switches to quench stage if any one of the superconducting magnets quenches (i.e., exceeding the current sharing temperature.) It is followed by the dumping stage after a given quench detection time. The recovery of the superconducting stage is allowed at any time step before dumping. The currents of each magnetic coil are calculated by a time-difference method. The thermohydraulic parameters during superconducting and quench/dumping stage are obtained by a finite element method. The size and location of each finite element are dynamically defined at each time step during quench and dumping. Calibrations against test data are presented.

  19. Traveling-wave-tube simulation: The IBC (Interactive Beam-Circuit) code

    SciTech Connect

    Morey, I.J.; Birdsall, C.K.

    1989-09-26

    Interactive Beam-Circuit (IBC) is a one-dimensional many particle simulation code which has been developed to run interactively on a PC or Workstation, and displaying most of the important physics of a traveling-wave-tube. The code is a substantial departure from previous efforts, since it follows all of the particles in the tube, rather than just those in one wavelength, as commonly done. This step allows for nonperiodic inputs in time, a nonuniform line and a large set of spatial diagnostics. The primary aim is to complement a microwave tube lecture course, although past experience has shown that such codes readily become research tools. Simple finite difference methods are used to model the fields of the coupled slow-wave transmission line. The coupling between the beam and the transmission line is based upon the finite difference equations of Brillouin. The space-charge effects are included, in a manner similar to that used by Hess; the original part is use of particle-in-cell techniques to model the space-charge fields. 11 refs., 11 figs.

  20. Noise tolerance in optical waveguide circuits for recognition of optical 16 quadrature amplitude modulation codes

    NASA Astrophysics Data System (ADS)

    Inoshita, Kensuke; Hama, Yoshimitsu; Kishikawa, Hiroki; Goto, Nobuo

    2016-12-01

    In photonic label routers, various optical signal processing functions are required; these include optical label extraction, recognition of the label, optical switching and buffering controlled by signals based on the label information and network routing tables, and label rewriting. Among these functions, we focus on photonic label recognition. We have proposed two kinds of optical waveguide circuits to recognize 16 quadrature amplitude modulation codes, i.e., recognition from the minimum output port and from the maximum output port. The recognition function was theoretically analyzed and numerically simulated by finite-difference beam-propagation method. We discuss noise tolerance in the circuit and show numerically simulated results to evaluate bit-error-rate (BER) characteristics against optical signal-to-noise ratio (OSNR). The OSNR required to obtain a BER less than 1.0×10-3 for the symbol rate of 2.5 GBaud was 14.5 and 27.0 dB for recognition from the minimum and maximum output, respectively.

  1. Simulation of TunneLadder traveling-wave tube cold-test characteristics: Implementation of the three-dimensional, electromagnetic circuit analysis code micro-SOS

    NASA Technical Reports Server (NTRS)

    Kory, Carol L.; Wilson, Jeffrey D.

    1993-01-01

    The three-dimensional, electromagnetic circuit analysis code, Micro-SOS, can be used to reduce expensive time-consuming experimental 'cold-testing' of traveling-wave tube (TWT) circuits. The frequency-phase dispersion characteristics and beam interaction impedance of a TunneLadder traveling-wave tube slow-wave structure were simulated using the code. When reasonable dimensional adjustments are made, computer results agree closely with experimental data. Modifications to the circuit geometry that would make the TunneLadder TWT easier to fabricate for higher frequency operation are explored.

  2. Nonlinear dynamics support a linear population code in a retinal target-tracking circuit.

    PubMed

    Leonardo, Anthony; Meister, Markus

    2013-10-23

    A basic task faced by the visual system of many organisms is to accurately track the position of moving prey. The retina is the first stage in the processing of such stimuli; the nature of the transformation here, from photons to spike trains, constrains not only the ultimate fidelity of the tracking signal but also the ease with which it can be extracted by other brain regions. Here we demonstrate that a population of fast-OFF ganglion cells in the salamander retina, whose dynamics are governed by a nonlinear circuit, serve to compute the future position of the target over hundreds of milliseconds. The extrapolated position of the target is not found by stimulus reconstruction but is instead computed by a weighted sum of ganglion cell outputs, the population vector average (PVA). The magnitude of PVA extrapolation varies systematically with target size, speed, and acceleration, such that large targets are tracked most accurately at high speeds, and small targets at low speeds, just as is seen in the motion of real prey. Tracking precision reaches the resolution of single photoreceptors, and the PVA algorithm performs more robustly than several alternative algorithms. If the salamander brain uses the fast-OFF cell circuit for target extrapolation as we suggest, the circuit dynamics should leave a microstructure on the behavior that may be measured in future experiments. Our analysis highlights the utility of simple computations that, while not globally optimal, are efficiently implemented and have close to optimal performance over a limited but ethologically relevant range of stimuli.

  3. Nonlinear Dynamics Support a Linear Population Code in a Retinal Target-Tracking Circuit

    PubMed Central

    Meister, Markus

    2013-01-01

    A basic task faced by the visual system of many organisms is to accurately track the position of moving prey. The retina is the first stage in the processing of such stimuli; the nature of the transformation here, from photons to spike trains, constrains not only the ultimate fidelity of the tracking signal but also the ease with which it can be extracted by other brain regions. Here we demonstrate that a population of fast-OFF ganglion cells in the salamander retina, whose dynamics are governed by a nonlinear circuit, serve to compute the future position of the target over hundreds of milliseconds. The extrapolated position of the target is not found by stimulus reconstruction but is instead computed by a weighted sum of ganglion cell outputs, the population vector average (PVA). The magnitude of PVA extrapolation varies systematically with target size, speed, and acceleration, such that large targets are tracked most accurately at high speeds, and small targets at low speeds, just as is seen in the motion of real prey. Tracking precision reaches the resolution of single photoreceptors, and the PVA algorithm performs more robustly than several alternative algorithms. If the salamander brain uses the fast-OFF cell circuit for target extrapolation as we suggest, the circuit dynamics should leave a microstructure on the behavior that may be measured in future experiments. Our analysis highlights the utility of simple computations that, while not globally optimal, are efficiently implemented and have close to optimal performance over a limited but ethologically relevant range of stimuli. PMID:24155302

  4. Cellular and circuit properties supporting different sensory coding strategies in electric fish and other systems.

    PubMed

    Marsat, Gary; Longtin, André; Maler, Leonard

    2012-08-01

    Neural codes often seem tailored to the type of information they must carry. Here we contrast the encoding strategies for two different communication signals in electric fish and describe the underlying cellular and network properties that implement them. We compare an aggressive signal that needs to be quickly detected, to a courtship signal whose quality needs to be evaluated. The aggressive signal is encoded by synchronized bursts and a predictive feedback input is crucial in separating background noise from the communication signal. The courtship signal is accurately encoded through a heterogenous population response allowing the discrimination of signal differences. Most importantly we show that the same strategies are used in other systems arguing that they evolved similar solutions because they faced similar tasks.

  5. Heat removal (wetting, heat transfer, T/H, secondary circuit, code validation etc.)

    SciTech Connect

    Dury, T.; Siman-Tov, M.

    1996-06-01

    This working group provided a comprehensive list of feasibility and uncertainty issues. Most of the issues seem to fall into the `needed but can be worked out` category. They feel these can be worked out as the project develops. A few issues can be considered critical or feasibility issues (that must be proven to be feasible). Those include: (1) Thermal shock and its mitigation (>1 MW); how to inject the He bubbles (if used) - back pressure into He lines - mercury traces in He lines; how to maintain proper bubble distribution and size (static and dynamic; if used); vibrations and fatigue (dynamic); possibility of cavitation from thermal shock. (2) Wetting and/or non-wetting of mercury on containment walls with or without gases and its effect on heat transfer (and materials). (3) Prediction capabilities in the CFD code; bubbles behavior in mercury (if used) - cross stream turbulence (ESS only) - wetting/non-wetting effects. (4) Cooling of beam `windows`; concentration of local heat deposition at center, especially if beam is of parabolic profile.

  6. Long non-coding RNA: a versatile regulator of the nuclear factor-κB signalling circuit.

    PubMed

    Mao, Xiaohua; Su, Zhenyi; Mookhtiar, Adnan K

    2017-04-01

    The nuclear factor-κB (NF-κB) family of transcription factors play an essential role for the regulation of inflammatory responses, immune function and malignant transformation. Aberrant activity of this signalling pathway may lead to inflammation, autoimmune diseases and oncogenesis. Over the last two decades great progress has been made in the understanding of NF-κB activation and how the response is counteracted for maintaining tissue homeostasis. Therapeutic targeting of this pathway has largely remained ineffective due to the widespread role of this vital pathway and the lack of specificity of the therapies currently available. Besides regulatory proteins and microRNAs, long non-coding RNA (lncRNA) is emerging as another critical layer of the intricate modulatory architecture for the control of the NF-κB signalling circuit. In this paper we focus on recent progress concerning lncRNA-mediated modulation of the NF-κB pathway, and evaluate the potential therapeutic uses and challenges of using lncRNAs that regulate NF-κB activity.

  7. Cellular and circuit mechanisms maintain low spike co-variability and enhance population coding in somatosensory cortex.

    PubMed

    Ly, Cheng; Middleton, Jason W; Doiron, Brent

    2012-01-01

    The responses of cortical neurons are highly variable across repeated presentations of a stimulus. Understanding this variability is critical for theories of both sensory and motor processing, since response variance affects the accuracy of neural codes. Despite this influence, the cellular and circuit mechanisms that shape the trial-to-trial variability of population responses remain poorly understood. We used a combination of experimental and computational techniques to uncover the mechanisms underlying response variability of populations of pyramidal (E) cells in layer 2/3 of rat whisker barrel cortex. Spike trains recorded from pairs of E-cells during either spontaneous activity or whisker deflected responses show similarly low levels of spiking co-variability, despite large differences in network activation between the two states. We developed network models that show how spike threshold non-linearities dilute E-cell spiking co-variability during spontaneous activity and low velocity whisker deflections. In contrast, during high velocity whisker deflections, cancelation mechanisms mediated by feedforward inhibition maintain low E-cell pairwise co-variability. Thus, the combination of these two mechanisms ensure low E-cell population variability over a wide range of whisker deflection velocities. Finally, we show how this active decorrelation of population variability leads to a drastic increase in the population information about whisker velocity. The prevalence of spiking non-linearities and feedforward inhibition in the nervous system suggests that the mechanisms for low network variability presented in our study may generalize throughout the brain.

  8. Cellular and Circuit Mechanisms Maintain Low Spike Co-Variability and Enhance Population Coding in Somatosensory Cortex

    PubMed Central

    Ly, Cheng; Middleton, Jason W.; Doiron, Brent

    2012-01-01

    The responses of cortical neurons are highly variable across repeated presentations of a stimulus. Understanding this variability is critical for theories of both sensory and motor processing, since response variance affects the accuracy of neural codes. Despite this influence, the cellular and circuit mechanisms that shape the trial-to-trial variability of population responses remain poorly understood. We used a combination of experimental and computational techniques to uncover the mechanisms underlying response variability of populations of pyramidal (E) cells in layer 2/3 of rat whisker barrel cortex. Spike trains recorded from pairs of E-cells during either spontaneous activity or whisker deflected responses show similarly low levels of spiking co-variability, despite large differences in network activation between the two states. We developed network models that show how spike threshold non-linearities dilute E-cell spiking co-variability during spontaneous activity and low velocity whisker deflections. In contrast, during high velocity whisker deflections, cancelation mechanisms mediated by feedforward inhibition maintain low E-cell pairwise co-variability. Thus, the combination of these two mechanisms ensure low E-cell population variability over a wide range of whisker deflection velocities. Finally, we show how this active decorrelation of population variability leads to a drastic increase in the population information about whisker velocity. The prevalence of spiking non-linearities and feedforward inhibition in the nervous system suggests that the mechanisms for low network variability presented in our study may generalize throughout the brain. PMID:22408615

  9. Solid state remote circuit selector switch

    NASA Technical Reports Server (NTRS)

    Peterson, V. S.

    1970-01-01

    Remote switching circuit utilizes voltage logic to switch on desired circuit. Circuit controls rotating multi-range pressure transducers in jet engine testing and can be used in coded remote circuit activator where sequence of switching has to occur in defined length of time to prevent false or undesired circuit activation.

  10. Measuring circuit

    DOEpatents

    Sun, Shan C.; Chaprnka, Anthony G.

    1977-01-11

    An automatic gain control circuit functions to adjust the magnitude of an input signal supplied to a measuring circuit to a level within the dynamic range of the measuring circuit while a log-ratio circuit adjusts the magnitude of the output signal from the measuring circuit to the level of the input signal and optimizes the signal-to-noise ratio performance of the measuring circuit.

  11. ADDER CIRCUIT

    DOEpatents

    Jacobsohn, D.H.; Merrill, L.C.

    1959-01-20

    An improved parallel addition unit is described which is especially adapted for use in electronic digital computers and characterized by propagation of the carry signal through each of a plurality of denominationally ordered stages within a minimum time interval. In its broadest aspects, the invention incorporates a fast multistage parallel digital adder including a plurality of adder circuits, carry-propagation circuit means in all but the most significant digit stage, means for conditioning each carry-propagation circuit during the time period in which information is placed into the adder circuits, and means coupling carry-generation portions of thc adder circuit to the carry propagating means.

  12. MULTIPLIER CIRCUIT

    DOEpatents

    Thomas, R.E.

    1959-01-20

    An electronic circuit is presented for automatically computing the product of two selected variables by multiplying the voltage pulses proportional to the variables. The multiplier circuit has a plurality of parallel resistors of predetermined values connected through separate gate circults between a first input and the output terminal. One voltage pulse is applied to thc flrst input while the second voltage pulse is applied to control circuitry for the respective gate circuits. Thc magnitude of the second voltage pulse selects the resistors upon which the first voltage pulse is imprcssed, whereby the resultant output voltage is proportional to the product of the input voltage pulses

  13. GATING CIRCUITS

    DOEpatents

    Merrill, L.C.

    1958-10-14

    Control circuits for vacuum tubes are described, and a binary counter having an improved trigger circuit is reported. The salient feature of the binary counter is the application of the input signal to the cathode of each of two vacuum tubes through separate capacitors and the connection of each cathode to ground through separate diodes. The control of the binary counter is achieved in this manner without special pulse shaping of the input signal. A further advantage of the circuit is the simplicity and minimum nuruber of components required, making its use particularly desirable in computer machines.

  14. 30 CFR 77.506-1 - Electric equipment and circuits; overload and short circuit protection; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Electric equipment and circuits; overload and...-1 Electric equipment and circuits; overload and short circuit protection; minimum requirements... minimum requirements for protection of electric circuits and equipment of the National Electric Code, 1968....

  15. 30 CFR 77.506-1 - Electric equipment and circuits; overload and short circuit protection; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Electric equipment and circuits; overload and...-1 Electric equipment and circuits; overload and short circuit protection; minimum requirements... minimum requirements for protection of electric circuits and equipment of the National Electric Code, 1968....

  16. 30 CFR 77.506-1 - Electric equipment and circuits; overload and short circuit protection; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Electric equipment and circuits; overload and...-1 Electric equipment and circuits; overload and short circuit protection; minimum requirements... minimum requirements for protection of electric circuits and equipment of the National Electric Code, 1968....

  17. 30 CFR 77.506-1 - Electric equipment and circuits; overload and short circuit protection; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Electric equipment and circuits; overload and...-1 Electric equipment and circuits; overload and short circuit protection; minimum requirements... minimum requirements for protection of electric circuits and equipment of the National Electric Code, 1968....

  18. 30 CFR 77.506-1 - Electric equipment and circuits; overload and short circuit protection; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Electric equipment and circuits; overload and...-1 Electric equipment and circuits; overload and short circuit protection; minimum requirements... minimum requirements for protection of electric circuits and equipment of the National Electric Code, 1968....

  19. Improved code-tracking loop

    NASA Technical Reports Server (NTRS)

    Laflame, D. T.

    1980-01-01

    Delay-locked loop tracks pseudonoise codes without introducing dc timing errors, because it is not sensitive to gain imbalance between signal processing arms. "Early" and "late" reference codes pass in combined form through both arms, and each arm acts on both codes. Circuit accomodates 1 dB weaker input signals with tracking ability equal to that of tau-dither loops.

  20. TRIPPING CIRCUIT

    DOEpatents

    Lees, G.W.; McCormick, E.D.

    1962-05-22

    A tripping circuit employing a magnetic amplifier for tripping a reactor in response to power level, period, or instrument failure is described. A reference winding and signal winding are wound in opposite directions on the core. Current from an ion chamber passes through both windings. If the current increases at too fast a rate, a shunt circuit bypasses one or the windings and the amplifier output reverses polarity. (AEC)

  1. Targeting circuits

    PubMed Central

    Rajasethupathy, Priyamvada; Ferenczi, Emily; Deisseroth, Karl

    2017-01-01

    Current optogenetic methodology enables precise inhibition or excitation of neural circuits, spanning timescales as needed from the acute (milliseconds) to the chronic (many days or more), for experimental modulation of network activity and animal behavior. Such broad temporal versatility, unique to optogenetic control, is particularly powerful when combined with brain activity measurements that span both acute and chronic timescales as well. This enables, for instance, the study of adaptive circuit dynamics across the intact brain, and tuning interventions to match activity patterns naturally observed during behavior in the same individual. Although the impact of this approach has been greater on basic research than on clinical translation, it is natural to ask if specific neural circuit activity patterns discovered to be involved in controlling adaptive or maladaptive behaviors could become targets for treatment of neuropsychiatric diseases. Here we consider the landscape of such ideas related to therapeutic targeting of circuit dynamics, taking note of developments not only in optical but also in ultrasonic, magnetic, and thermal methods. We note the recent emergence of first-in-kind optogenetically-guided clinical outcomes, as well as opportunities related to the integration of interventions and readouts spanning diverse circuit-physiology, molecular, and behavioral modalities. PMID:27104976

  2. Low cost design of microprocessor EDAC circuit

    NASA Astrophysics Data System (ADS)

    Li, Hao; Lixin, Yu; Heping, Peng; Wei, Zhuang

    2015-11-01

    An optimization method of error detection and correction (EDAC) circuit design is proposed. The method involves selecting or constructing EDAC codes of low cost hardware, associated with operation scheduling implementation based on 2-input XOR gates structure, and two actions for reducing hardware cells, which can reduce the delay penalties and area costs of the EDAC circuit effectively. The 32-bit EDAC circuit hardware implementation is selected to make a prototype, based on the 180 nm process. The delay penalties and area costs of the EDAC circuit are evaluated. Results show that the time penalty and area cost of the EDAC circuitries are affected with different parity-check matrices and different hardware implementation for the EDAC codes with the same capability of correction and detection code. This method can be used as a guide for low-cost radiation-hardened microprocessor EDAC circuit design and for more advanced technologies.

  3. Trigger Circuit.

    DTIC Science & Technology

    A wire of Nitinol can be stretched up to a given amount and will remain in this stretched state until heated to a critical temperature. When heated...circuit of this invention provides a current pulse for the required time period to heat the Nitinol wire to its critical temperature to thereby restore the...wire to its original length. The circuit includes a high power transistor which is gated on for a controlled time to provide the required power to heat the Nitinol wire to its critical temperature. (Author)

  4. MULTIPLIER CIRCUIT

    DOEpatents

    Chase, R.L.

    1963-05-01

    An electronic fast multiplier circuit utilizing a transistor controlled voltage divider network is presented. The multiplier includes a stepped potentiometer in which solid state or transistor switches are substituted for mechanical wipers in order to obtain electronic switching that is extremely fast as compared to the usual servo-driven mechanical wipers. While this multiplier circuit operates as an approximation and in steps to obtain a voltage that is the product of two input voltages, any desired degree of accuracy can be obtained with the proper number of increments and adjustment of parameters. (AEC)

  5. Active FPGA Security Through Decoy Circuits

    DTIC Science & Technology

    2006-03-01

    FPGA and is reported in the units provided by the FPGA software that converts a circuit schematic and/or VHDL code to an FPGA programming file. Power...described by truth or state tables and by Boolean Equations, in a gate-level representation, and in existing VHDL code are provided. The method for...The following is the VHDL code for a Combination Lock with eight states and three inputs. -- original state machine code from Doug Hodson’s -- L

  6. Thermionic integrated circuits

    SciTech Connect

    MacRoberts, M.; Brown, D.R.; Dooley, R.; Lemons, R.; Lynn, D.; McCormick, B.; Mombourquette, C.; Sinah, D.

    1986-01-01

    Thermionic integrated circuits combine vacuum-tube technology with integrated-circuit techniques to form integrated vacuum circuits. These circuits are capable of extended operation in both high-temperature and high-radiation environments.

  7. Circuit design tool. User's manual, revision 2

    NASA Technical Reports Server (NTRS)

    Miyake, Keith M.; Smith, Donald E.

    1992-01-01

    The CAM chip design was produced in a UNIX software environment using a design tool that supports definition of digital electronic modules, composition of these modules into higher level circuits, and event-driven simulation of these circuits. Our design tool provides an interface whose goals include straightforward but flexible primitive module definition and circuit composition, efficient simulation, and a debugging environment that facilitates design verification and alteration. The tool provides a set of primitive modules which can be composed into higher level circuits. Each module is a C-language subroutine that uses a set of interface protocols understood by the design tool. Primitives can be altered simply by recoding their C-code image; in addition new primitives can be added allowing higher level circuits to be described in C-code rather than as a composition of primitive modules--this feature can greatly enhance the speed of simulation.

  8. LOGIC CIRCUIT

    DOEpatents

    Strong, G.H.; Faught, M.L.

    1963-12-24

    A device for safety rod counting in a nuclear reactor is described. A Wheatstone bridge circuit is adapted to prevent de-energizing the hopper coils of a ball backup system if safety rods, sufficient in total control effect, properly enter the reactor core to effect shut down. A plurality of resistances form one arm of the bridge, each resistance being associated with a particular safety rod and weighted in value according to the control effect of the particular safety rod. Switching means are used to switch each of the resistances in and out of the bridge circuit responsive to the presence of a particular safety rod in its effective position in the reactor core and responsive to the attainment of a predetermined velocity by a particular safety rod enroute to its effective position. The bridge is unbalanced in one direction during normal reactor operation prior to the generation of a scram signal and the switching means and resistances are adapted to unbalance the bridge in the opposite direction if the safety rods produce a predetermined amount of control effect in response to the scram signal. The bridge unbalance reversal is then utilized to prevent the actuation of the ball backup system, or, conversely, a failure of the safety rods to produce the predetermined effect produces no unbalance reversal and the ball backup system is actuated. (AEC)

  9. Polar Codes

    DTIC Science & Technology

    2014-12-01

    density parity check (LDPC) code, a Reed–Solomon code, and three convolutional codes. iii CONTENTS EXECUTIVE SUMMARY...the most common. Many civilian systems use low density parity check (LDPC) FEC codes, and the Navy is planning to use LDPC for some future systems...other forward error correction methods: a turbo code, a low density parity check (LDPC) code, a Reed–Solomon code, and three convolutional codes

  10. Transversal Clifford gates on folded surface codes

    SciTech Connect

    Moussa, Jonathan E.

    2016-10-12

    Surface and color codes are two forms of topological quantum error correction in two spatial dimensions with complementary properties. Surface codes have lower-depth error detection circuits and well-developed decoders to interpret and correct errors, while color codes have transversal Clifford gates and better code efficiency in the number of physical qubits needed to achieve a given code distance. A formal equivalence exists between color codes and folded surface codes, but it does not guarantee the transferability of any of these favorable properties. However, the equivalence does imply the existence of constant-depth circuit implementations of logical Clifford gates on folded surface codes. We achieve and improve this result by constructing two families of folded surface codes with transversal Clifford gates. This construction is presented generally for qudits of any dimension. Lastly, the specific application of these codes to universal quantum computation based on qubit fusion is also discussed.

  11. Transversal Clifford gates on folded surface codes

    DOE PAGES

    Moussa, Jonathan E.

    2016-10-12

    Surface and color codes are two forms of topological quantum error correction in two spatial dimensions with complementary properties. Surface codes have lower-depth error detection circuits and well-developed decoders to interpret and correct errors, while color codes have transversal Clifford gates and better code efficiency in the number of physical qubits needed to achieve a given code distance. A formal equivalence exists between color codes and folded surface codes, but it does not guarantee the transferability of any of these favorable properties. However, the equivalence does imply the existence of constant-depth circuit implementations of logical Clifford gates on folded surfacemore » codes. We achieve and improve this result by constructing two families of folded surface codes with transversal Clifford gates. This construction is presented generally for qudits of any dimension. Lastly, the specific application of these codes to universal quantum computation based on qubit fusion is also discussed.« less

  12. Transversal Clifford gates on folded surface codes

    NASA Astrophysics Data System (ADS)

    Moussa, Jonathan E.

    2016-10-01

    Surface and color codes are two forms of topological quantum error correction in two spatial dimensions with complementary properties. Surface codes have lower-depth error detection circuits and well-developed decoders to interpret and correct errors, while color codes have transversal Clifford gates and better code efficiency in the number of physical qubits needed to achieve a given code distance. A formal equivalence exists between color codes and folded surface codes, but it does not guarantee the transferability of any of these favorable properties. However, the equivalence does imply the existence of constant-depth circuit implementations of logical Clifford gates on folded surface codes. We achieve and improve this result by constructing two families of folded surface codes with transversal Clifford gates. This construction is presented generally for qudits of any dimension. The specific application of these codes to universal quantum computation based on qubit fusion is also discussed.

  13. Commutation circuit for an HVDC circuit breaker

    DOEpatents

    Premerlani, William J.

    1981-01-01

    A commutation circuit for a high voltage DC circuit breaker incorporates a resistor capacitor combination and a charging circuit connected to the main breaker, such that a commutating capacitor is discharged in opposition to the load current to force the current in an arc after breaker opening to zero to facilitate arc interruption. In a particular embodiment, a normally open commutating circuit is connected across the contacts of a main DC circuit breaker to absorb the inductive system energy trapped by breaker opening and to limit recovery voltages to a level tolerable by the commutating circuit components.

  14. Commutation circuit for an HVDC circuit breaker

    DOEpatents

    Premerlani, W.J.

    1981-11-10

    A commutation circuit for a high voltage DC circuit breaker incorporates a resistor capacitor combination and a charging circuit connected to the main breaker, such that a commutating capacitor is discharged in opposition to the load current to force the current in an arc after breaker opening to zero to facilitate arc interruption. In a particular embodiment, a normally open commutating circuit is connected across the contacts of a main DC circuit breaker to absorb the inductive system energy trapped by breaker opening and to limit recovery voltages to a level tolerable by the commutating circuit components. 13 figs.

  15. Clinical coding. Code breakers.

    PubMed

    Mathieson, Steve

    2005-02-24

    --The advent of payment by results has seen the role of the clinical coder pushed to the fore in England. --Examinations for a clinical coding qualification began in 1999. In 2004, approximately 200 people took the qualification. --Trusts are attracting people to the role by offering training from scratch or through modern apprenticeships.

  16. Circuit monitors powerline interruptions

    NASA Technical Reports Server (NTRS)

    Simmons, N. E.; Stricklen, J. O.

    1977-01-01

    Simple circuit when combined with pulse detector detects momentary interruptions of 400-cycle ac signal. Circuit has been used during shock and vibration testing of electronic hardware to determine if tests caused interruptions of normal circuit operation.

  17. A simple tachometer circuit

    NASA Technical Reports Server (NTRS)

    Dimeff, J.

    1972-01-01

    Electric circuit to measure frequency of repetitive sinusoidal or rectangular wave is presented. Components of electric circuit and method of operation are explained. Application of circuit as tachometer for automobile is discussed.

  18. Sensor Authentication: Embedded Processor Code

    SciTech Connect

    Svoboda, John

    2012-09-25

    Described is the c code running on the embedded Microchip 32bit PIC32MX575F256H located on the INL developed noise analysis circuit board. The code performs the following functions: Controls the noise analysis circuit board preamplifier voltage gains of 1, 10, 100, 000 Initializes the analog to digital conversion hardware, input channel selection, Fast Fourier Transform (FFT) function, USB communications interface, and internal memory allocations Initiates high resolution 4096 point 200 kHz data acquisition Computes complex 2048 point FFT and FFT magnitude. Services Host command set Transfers raw data to Host Transfers FFT result to host Communication error checking

  19. Beyond Molecular Codes: Simple Rules to Wire Complex Brains

    PubMed Central

    Hassan, Bassem A.; Hiesinger, P. Robin

    2015-01-01

    Summary Molecular codes, like postal zip codes, are generally considered a robust way to ensure the specificity of neuronal target selection. However, a code capable of unambiguously generating complex neural circuits is difficult to conceive. Here, we re-examine the notion of molecular codes in the light of developmental algorithms. We explore how molecules and mechanisms that have been considered part of a code may alternatively implement simple pattern formation rules sufficient to ensure wiring specificity in neural circuits. This analysis delineates a pattern-based framework for circuit construction that may contribute to our understanding of brain wiring. PMID:26451480

  20. Simple Autonomous Chaotic Circuits

    NASA Astrophysics Data System (ADS)

    Piper, Jessica; Sprott, J.

    2010-03-01

    Over the last several decades, numerous electronic circuits exhibiting chaos have been proposed. Non-autonomous circuits with as few as two components have been developed. However, the operation of such circuits relies on the non-ideal behavior of the devices used, and therefore the circuit equations can be quite complex. In this paper, we present two simple autonomous chaotic circuits using only opamps and linear passive components. The circuits each use one opamp as a comparator, to provide a signum nonlinearity. The chaotic behavior is robust, and independent of nonlinearities in the passive components. Moreover, the circuit equations are among the algebraically simplest chaotic systems yet constructed.

  1. Shift register generators and applications to coding

    NASA Technical Reports Server (NTRS)

    Morakis, J. C.

    1968-01-01

    The most important properties of shift register generated sequences are exposed. The application of shift registers as multiplication and division circuits leads to the generation of some error correcting and detecting codes.

  2. Solenoid-Simulation Circuit

    NASA Technical Reports Server (NTRS)

    Simon, R. A.

    1986-01-01

    Electrical properties of solenoids imitated for tests of control circuits. Simulation circuit imitates voltage and current responses of two engine-controlling solenoids. Used in tests of programs of digital engine-control circuits, also provides electronic interface with circuits imitating electrical properties of pressure sensors and linear variable-differential transformers. Produces voltages, currents, delays, and discrete turnon and turnoff signals representing operation of solenoid in engine-control relay. Many such circuits used simulating overall engine circuitry.

  3. Hidden circuits and argumentation

    NASA Astrophysics Data System (ADS)

    Leinonen, Risto; Kesonen, Mikko H. P.; Hirvonen, Pekka E.

    2016-11-01

    Despite the relevance of DC circuits in everyday life and schools, they have been shown to cause numerous learning difficulties at various school levels. In the course of this article, we present a flexible method for teaching DC circuits at lower secondary level. The method is labelled as hidden circuits, and the essential idea underlying hidden circuits is in hiding the actual wiring of DC circuits, but to make their behaviour evident for pupils. Pupils are expected to find out the wiring of the circuit which should enhance their learning of DC circuits. We present two possible ways to utilise hidden circuits in a classroom. First, they can be used to test and enhance pupils’ conceptual understanding when pupils are expected to find out which one of the offered circuit diagram options corresponds to the actual circuit shown. This method aims to get pupils to evaluate the circuits holistically rather than locally, and as a part of that aim this method highlights any learning difficulties of pupils. Second, hidden circuits can be used to enhance pupils’ argumentation skills with the aid of argumentation sheet that illustrates the main elements of an argument. Based on the findings from our co-operating teachers and our own experiences, hidden circuits offer a flexible and motivating way to supplement teaching of DC circuits.

  4. Parallel algorithm strategies for circuit simulation.

    SciTech Connect

    Thornquist, Heidi K.; Schiek, Richard Louis; Keiter, Eric Richard

    2010-01-01

    Circuit simulation tools (e.g., SPICE) have become invaluable in the development and design of electronic circuits. However, they have been pushed to their performance limits in addressing circuit design challenges that come from the technology drivers of smaller feature scales and higher integration. Improving the performance of circuit simulation tools through exploiting new opportunities in widely-available multi-processor architectures is a logical next step. Unfortunately, not all traditional simulation applications are inherently parallel, and quickly adapting mature application codes (even codes designed to parallel applications) to new parallel paradigms can be prohibitively difficult. In general, performance is influenced by many choices: hardware platform, runtime environment, languages and compilers used, algorithm choice and implementation, and more. In this complicated environment, the use of mini-applications small self-contained proxies for real applications is an excellent approach for rapidly exploring the parameter space of all these choices. In this report we present a multi-core performance study of Xyce, a transistor-level circuit simulation tool, and describe the future development of a mini-application for circuit simulation.

  5. Optical system facilitates inspection of printed circuit boards

    NASA Technical Reports Server (NTRS)

    Cridlin, M.; Oconnor, J.

    1968-01-01

    Optical comparator method determines the quality and registration of surface features of double-sided printed circuit boards. Color-coded superimposed images of both sides of a printed circuit board are presented to view, clearly showing details and registration of the circuitry.

  6. Ethical coding.

    PubMed

    Resnik, Barry I

    2009-01-01

    It is ethical, legal, and proper for a dermatologist to maximize income through proper coding of patient encounters and procedures. The overzealous physician can misinterpret reimbursement requirements or receive bad advice from other physicians and cross the line from aggressive coding to coding fraud. Several of the more common problem areas are discussed.

  7. Electrical Circuits and Water Analogies

    ERIC Educational Resources Information Center

    Smith, Frederick A.; Wilson, Jerry D.

    1974-01-01

    Briefly describes water analogies for electrical circuits and presents plans for the construction of apparatus to demonstrate these analogies. Demonstrations include series circuits, parallel circuits, and capacitors. (GS)

  8. Linear integrated circuits

    NASA Astrophysics Data System (ADS)

    Young, T.

    This book is intended to be used as a textbook in a one-semester course at a variety of levels. Because of self-study features incorporated, it may also be used by practicing electronic engineers as a formal and thorough introduction to the subject. The distinction between linear and digital integrated circuits is discussed, taking into account digital and linear signal characteristics, linear and digital integrated circuit characteristics, the definitions for linear and digital circuits, applications of digital and linear integrated circuits, aspects of fabrication, packaging, and classification and numbering. Operational amplifiers are considered along with linear integrated circuit (LIC) power requirements and power supplies, voltage and current regulators, linear amplifiers, linear integrated circuit oscillators, wave-shaping circuits, active filters, DA and AD converters, demodulators, comparators, instrument amplifiers, current difference amplifiers, analog circuits and devices, and aspects of troubleshooting.

  9. Sense circuit arrangement

    NASA Technical Reports Server (NTRS)

    Bohning, Oliver D. (Inventor)

    1976-01-01

    A unique, two-node sense circuit is disclosed. The circuit includes a bridge comprised of resistance elements and a differential amplifier. The two-node circuit is suitably adapted to be arranged in an array comprised of a plurality of discrete bridge-amplifiers which can be selectively energized. The circuit is arranged so as to form a configuration with minimum power utilization and a reduced number of components and interconnections therebetween.

  10. Piezoelectric drive circuit

    DOEpatents

    Treu, C.A. Jr.

    1999-08-31

    A piezoelectric motor drive circuit is provided which utilizes the piezoelectric elements as oscillators and a Meacham half-bridge approach to develop feedback from the motor ground circuit to produce a signal to drive amplifiers to power the motor. The circuit automatically compensates for shifts in harmonic frequency of the piezoelectric elements due to pressure and temperature changes. 7 figs.

  11. Piezoelectric drive circuit

    DOEpatents

    Treu, Jr., Charles A.

    1999-08-31

    A piezoelectric motor drive circuit is provided which utilizes the piezoelectric elements as oscillators and a Meacham half-bridge approach to develop feedback from the motor ground circuit to produce a signal to drive amplifiers to power the motor. The circuit automatically compensates for shifts in harmonic frequency of the piezoelectric elements due to pressure and temperature changes.

  12. Genealogy of Chua's Circuit

    NASA Astrophysics Data System (ADS)

    Kennedy, Peter

    2013-01-01

    Since its invention in 1983, Chua's circuit has become a reference circuit for studying bifurcations and chaos. This chapter plots the evolution of the circuit from the original simulations and experimental realization of a five-element topology with a three-segment nonlinear resistor to the latest three-element design comprising a capacitor, an inductor, and a memristor.

  13. Integrated Circuit Computer Analysis.

    DTIC Science & Technology

    information on this topic. The most important findings were the method used to identify combinational circuits ( Quine - McCluskey algorithm) and a clearly...defined set of limits on the problem of identifying sequential circuits. Since the Quine - McCluskey algorithm works only for combinational circuits, an

  14. Asynchronous ASCII Event Count Status Code

    DTIC Science & Technology

    2012-03-01

    IRIG STANDARD 215-12 TELECOMMUNICATIONS AND TIMING GROUP ASYNCHRONOUS ASCII EVENT COUNT STATUS CODES...Inter-range Instrumentation Group ( IRIG ) Standard for American Standard Code for Information Interchange (ASCII)-formatted EC status transfer which can be...circuits and Ethernet networks. Provides systems engineers and equipment vendors with an Inter-range Instrumentation Group ( IRIG ) Standard for American

  15. Error coding simulations

    NASA Technical Reports Server (NTRS)

    Noble, Viveca K.

    1993-01-01

    There are various elements such as radio frequency interference (RFI) which may induce errors in data being transmitted via a satellite communication link. When a transmission is affected by interference or other error-causing elements, the transmitted data becomes indecipherable. It becomes necessary to implement techniques to recover from these disturbances. The objective of this research is to develop software which simulates error control circuits and evaluate the performance of these modules in various bit error rate environments. The results of the evaluation provide the engineer with information which helps determine the optimal error control scheme. The Consultative Committee for Space Data Systems (CCSDS) recommends the use of Reed-Solomon (RS) and convolutional encoders and Viterbi and RS decoders for error correction. The use of forward error correction techniques greatly reduces the received signal to noise needed for a certain desired bit error rate. The use of concatenated coding, e.g. inner convolutional code and outer RS code, provides even greater coding gain. The 16-bit cyclic redundancy check (CRC) code is recommended by CCSDS for error detection.

  16. Mitochondrial ion circuits.

    PubMed

    Nicholls, David G

    2010-01-01

    Proton circuits across the inner mitochondrial membrane link the primary energy generators, namely the complexes of the electron transport chain, to multiple energy utilizing processes, including the ATP synthase, inherent proton leak pathways, metabolite transport and linked circuits of sodium and calcium. These mitochondrial circuits can be monitored in both isolated preparations and intact cells and, for the primary proton circuit techniques, exist to follow both the proton current and proton electrochemical potential components of the circuit in parallel experiments, providing a quantitative means of assessing mitochondrial function and, equally importantly, dysfunction.

  17. CIRCUITS FOR CURRENT MEASUREMENTS

    DOEpatents

    Cox, R.J.

    1958-11-01

    Circuits are presented for measurement of a logarithmic scale of current flowing in a high impedance. In one form of the invention the disclosed circuit is in combination with an ionization chamber to measure lonization current. The particular circuit arrangement lncludes a vacuum tube having at least one grid, an ionization chamber connected in series with a high voltage source and the grid of the vacuum tube, and a d-c amplifier feedback circuit. As the ionization chamber current passes between the grid and cathode of the tube, the feedback circuit acts to stabilize the anode current, and the feedback voltage is a measure of the logaritbm of the ionization current.

  18. Sharing code.

    PubMed

    Kubilius, Jonas

    2014-01-01

    Sharing code is becoming increasingly important in the wake of Open Science. In this review I describe and compare two popular code-sharing utilities, GitHub and Open Science Framework (OSF). GitHub is a mature, industry-standard tool but lacks focus towards researchers. In comparison, OSF offers a one-stop solution for researchers but a lot of functionality is still under development. I conclude by listing alternative lesser-known tools for code and materials sharing.

  19. Spring Break: A Lesson in Circuits. "This Old House" College Style.

    ERIC Educational Resources Information Center

    Duch, Barbara

    2001-01-01

    Introduces students to the topics of electricity and circuits within the context of house wiring. Explores the properties of series and parallel circuits, researches local wiring codes, calculates the current used by appliances based on their power ratings, and designs circuits in a typical kitchen. (Author/ASK)

  20. Parallelizing quantum circuit synthesis

    NASA Astrophysics Data System (ADS)

    Di Matteo, Olivia; Mosca, Michele

    2016-03-01

    Quantum circuit synthesis is the process in which an arbitrary unitary operation is decomposed into a sequence of gates from a universal set, typically one which a quantum computer can implement both efficiently and fault-tolerantly. As physical implementations of quantum computers improve, the need is growing for tools that can effectively synthesize components of the circuits and algorithms they will run. Existing algorithms for exact, multi-qubit circuit synthesis scale exponentially in the number of qubits and circuit depth, leaving synthesis intractable for circuits on more than a handful of qubits. Even modest improvements in circuit synthesis procedures may lead to significant advances, pushing forward the boundaries of not only the size of solvable circuit synthesis problems, but also in what can be realized physically as a result of having more efficient circuits. We present a method for quantum circuit synthesis using deterministic walks. Also termed pseudorandom walks, these are walks in which once a starting point is chosen, its path is completely determined. We apply our method to construct a parallel framework for circuit synthesis, and implement one such version performing optimal T-count synthesis over the Clifford+T gate set. We use our software to present examples where parallelization offers a significant speedup on the runtime, as well as directly confirm that the 4-qubit 1-bit full adder has optimal T-count 7 and T-depth 3.

  1. Coupled gas discharge and pulse circuit analysis

    NASA Astrophysics Data System (ADS)

    von Dadelszen, Michael; Rothe, Dietmar E.

    1991-04-01

    Two examples of the importance of accurate coupling of driving electric circuits to discharge models, when simulating fast pulse discharges, are presented. The first example uses a commercial electric field analysis code, TETRAelf, to simulate a pulsed discharge TEA CO2 laser and demonstrates the value of including displacement current effects in the modeling of the avalanche phase of the discharge. The second example uses a commercial electric circuit analysis package, ECA, to simulate a three-electrode, long-pulse, 2-J, XeCl excimer laser. Both the saturable magnetic cores and the discharge kinetics are included in the simulation. Comparisons are made between the numerical results and experimental data.

  2. Remote reset circuit

    DOEpatents

    Gritzo, Russell E.

    1987-01-01

    A remote reset circuit acts as a stand-alone monitor and controller by clocking in each character sent by a terminal to a computer and comparing it to a given reference character. When a match occurs, the remote reset circuit activates the system's hardware reset line. The remote reset circuit is hardware based centered around monostable multivibrators and is unaffected by system crashes, partial serial transmissions, or power supply transients.

  3. Regenerative feedback resonant circuit

    DOEpatents

    Jones, A. Mark; Kelly, James F.; McCloy, John S.; McMakin, Douglas L.

    2014-09-02

    A regenerative feedback resonant circuit for measuring a transient response in a loop is disclosed. The circuit includes an amplifier for generating a signal in the loop. The circuit further includes a resonator having a resonant cavity and a material located within the cavity. The signal sent into the resonator produces a resonant frequency. A variation of the resonant frequency due to perturbations in electromagnetic properties of the material is measured.

  4. Multiplier less high-speed squaring circuit for binary numbers

    NASA Astrophysics Data System (ADS)

    Sethi, Kabiraj; Panda, Rutuparna

    2015-03-01

    The squaring operation is important in many applications in signal processing, cryptography etc. In general, squaring circuits reported in the literature use fast multipliers. A novel idea of a squaring circuit without using multipliers is proposed in this paper. Ancient Indian method used for squaring decimal numbers is extended here for binary numbers. The key to our success is that no multiplier is used. Instead, one squaring circuit is used. The hardware architecture of the proposed squaring circuit is presented. The design is coded in VHDL and synthesised and simulated in Xilinx ISE Design Suite 10.1 (Xilinx Inc., San Jose, CA, USA). It is implemented in Xilinx Vertex 4vls15sf363-12 device (Xilinx Inc.). The results in terms of time delay and area is compared with both modified Booth's algorithm and squaring circuit using Vedic multipliers. Our proposed squaring circuit seems to have better performance in terms of both speed and area.

  5. Sharing code

    PubMed Central

    Kubilius, Jonas

    2014-01-01

    Sharing code is becoming increasingly important in the wake of Open Science. In this review I describe and compare two popular code-sharing utilities, GitHub and Open Science Framework (OSF). GitHub is a mature, industry-standard tool but lacks focus towards researchers. In comparison, OSF offers a one-stop solution for researchers but a lot of functionality is still under development. I conclude by listing alternative lesser-known tools for code and materials sharing. PMID:25165519

  6. In-circuit fault injector user's guide

    NASA Technical Reports Server (NTRS)

    Padilla, Peter A.

    1987-01-01

    A fault injector system, called an in-circuit injector, was designed and developed to facilitate fault injection experiments performed at NASA-Langley's Avionics Integration Research Lab (AIRLAB). The in-circuit fault injector (ICFI) allows fault injections to be performed on electronic systems without special test features, e.g., sockets. The system supports stuck-at-zero, stuck-at-one, and transient fault models. The ICFI system is interfaced to a VAX-11/750 minicomputer. An interface program has been developed in the VAX. The computer code required to access the interface program is presented. Also presented is the connection procedure to be followed to connect the ICFI system to a circuit under test and the ICFI front panel controls which allow manual control of fault injections.

  7. Driver Code for Adaptive Optics

    NASA Technical Reports Server (NTRS)

    Rao, Shanti

    2007-01-01

    A special-purpose computer code for a deformable-mirror adaptive-optics control system transmits pixel-registered control from (1) a personal computer running software that generates the control data to (2) a circuit board with 128 digital-to-analog converters (DACs) that generate voltages to drive the deformable-mirror actuators. This program reads control-voltage codes from a text file, then sends them, via the computer s parallel port, to a circuit board with four AD5535 (or equivalent) chips. Whereas a similar prior computer program was capable of transmitting data to only one chip at a time, this program can send data to four chips simultaneously. This program is in the form of C-language code that can be compiled and linked into an adaptive-optics software system. The program as supplied includes source code for integration into the adaptive-optics software, documentation, and a component that provides a demonstration of loading DAC codes from a text file. On a standard Windows desktop computer, the software can update 128 channels in 10 ms. On Real-Time Linux with a digital I/O card, the software can update 1024 channels (8 boards in parallel) every 8 ms.

  8. Catheter transducer and circuit

    NASA Technical Reports Server (NTRS)

    Harrison, D. R.; Kerwin, W. J.

    1971-01-01

    Simple integrated circuit located at transducer, enables use of single coaxial cable for both input and output connections. Circuit is sensitive to changes in RC time constant, has much improved sensitivity characteristics, and is unaffected by changes in cable capacitance effects.

  9. A Virtual Circuits Lab

    ERIC Educational Resources Information Center

    Vick, Matthew E.

    2010-01-01

    The University of Colorado's Physics Education Technology (PhET) website offers free, high-quality simulations of many physics experiments that can be used in the classroom. The Circuit Construction Kit, for example, allows students to safely and constructively play with circuit components while learning the mathematics behind many circuit…

  10. Understanding Simple Circuits

    ERIC Educational Resources Information Center

    Mant, Jenny; Wilson, Helen

    2007-01-01

    Many envisage electricity as the "power" to "do things." They know that electricity needs "circuits" and that something is "flowing" in the circuits, but they are not sure what or why. Words such as "current" and "voltage" are part of electricity but their meaning, and the difference between them, is not always clear. In this article, the authors…

  11. Liquid detection circuit

    DOEpatents

    Regan, Thomas O.

    1987-01-01

    Herein is a circuit which is capable of detecting the presence of liquids, especially cryogenic liquids, and whose sensor will not overheat in a vacuum. The circuit parameters, however, can be adjusted to work with any liquid over a wide range of temperatures.

  12. Completing a Simple Circuit.

    ERIC Educational Resources Information Center

    Slater, Timothy F.; Adams, Jeffrey P.; Brown, Thomas R.

    2000-01-01

    Students have problems successfully arranging an electric circuit to make the bulb produce light. Investigates the percentage of students able to complete a circuit with a given apparatus, and the effects of prior experience on student success. Recommends hands-on activities at the elementary and secondary school levels. (Contains 14 references.)…

  13. Thermocouple-Signal-Conditioning Circuit

    NASA Technical Reports Server (NTRS)

    Simon, Richard A.

    1991-01-01

    Thermocouple-signal-conditioning circuit acting in conjunction with thermocouple, exhibits electrical behavior of voltage in series with resistance. Combination part of input bridge circuit of controller. Circuit configured for either of two specific applications by selection of alternative resistances and supply voltages. Includes alarm circuit detecting open circuit in thermocouple and provides off-scale output to signal malfunctions.

  14. SLINGSHOT - a Coilgun Design Code

    SciTech Connect

    MARDER, BARRY M.

    2001-09-01

    The Sandia coilgun [1,2,3,4,5] is an inductive electromagnetic launcher. It consists of a sequence of powered, multi-turn coils surrounding a flyway of circular cross-section through which a conducting armature passes. When the armature is properly positioned with respect to a coil, a charged capacitor is switched into the coil circuit. The rising coil currents induce a current in the armature, producing a repulsive accelerating force. The basic numerical tool for modeling the coilgun is the SLINGSHOT code, an expanded, user-friendly successor to WARP-10 [6]. SLINGSHOT computes the currents in the coils and armature, finds the forces produced by those currents, and moves the armature through the array of coils. In this approach, the cylindrically symmetric coils and armature are subdivided into concentric hoops with rectangular cross-section, in each of which the current is assumed to be uniform. The ensemble of hoops are treated as coupled circuits. The specific heats and resistivities of the hoops are found as functions of temperature and used to determine the resistive heating. The code calculates the resistances and inductances for all hoops, and the mutual inductances for all hoop pairs. Using these, it computes the hoop currents from their circuit equations, finds the forces from the products of these currents and the mutual inductance gradient, and moves the armature. Treating the problem as a set of coupled circuits is a fast and accurate approach compared to solving the field equations. Its use, however, is restricted to problems in which the symmetry dictates the current paths. This paper is divided into three parts. The first presents a demonstration of the code. The second describes the input and output. The third part describes the physical models and numerical methods used in the code. It is assumed that the reader is familiar with coilguns.

  15. Compensated gain control circuit for buck regulator command charge circuit

    DOEpatents

    Barrett, David M.

    1996-01-01

    A buck regulator command charge circuit includes a compensated-gain control signal for compensating for changes in the component values in order to achieve optimal voltage regulation. The compensated-gain control circuit includes an automatic-gain control circuit for generating a variable-gain control signal. The automatic-gain control circuit is formed of a precision rectifier circuit, a filter network, an error amplifier, and an integrator circuit.

  16. Compensated gain control circuit for buck regulator command charge circuit

    DOEpatents

    Barrett, D.M.

    1996-11-05

    A buck regulator command charge circuit includes a compensated-gain control signal for compensating for changes in the component values in order to achieve optimal voltage regulation. The compensated-gain control circuit includes an automatic-gain control circuit for generating a variable-gain control signal. The automatic-gain control circuit is formed of a precision rectifier circuit, a filter network, an error amplifier, and an integrator circuit. 5 figs.

  17. Approximate circuits for increased reliability

    DOEpatents

    Hamlet, Jason R.; Mayo, Jackson R.

    2015-12-22

    Embodiments of the invention describe a Boolean circuit having a voter circuit and a plurality of approximate circuits each based, at least in part, on a reference circuit. The approximate circuits are each to generate one or more output signals based on values of received input signals. The voter circuit is to receive the one or more output signals generated by each of the approximate circuits, and is to output one or more signals corresponding to a majority value of the received signals. At least some of the approximate circuits are to generate an output value different than the reference circuit for one or more input signal values; however, for each possible input signal value, the majority values of the one or more output signals generated by the approximate circuits and received by the voter circuit correspond to output signal result values of the reference circuit.

  18. Approximate circuits for increased reliability

    SciTech Connect

    Hamlet, Jason R.; Mayo, Jackson R.

    2015-08-18

    Embodiments of the invention describe a Boolean circuit having a voter circuit and a plurality of approximate circuits each based, at least in part, on a reference circuit. The approximate circuits are each to generate one or more output signals based on values of received input signals. The voter circuit is to receive the one or more output signals generated by each of the approximate circuits, and is to output one or more signals corresponding to a majority value of the received signals. At least some of the approximate circuits are to generate an output value different than the reference circuit for one or more input signal values; however, for each possible input signal value, the majority values of the one or more output signals generated by the approximate circuits and received by the voter circuit correspond to output signal result values of the reference circuit.

  19. Speech coding

    SciTech Connect

    Ravishankar, C., Hughes Network Systems, Germantown, MD

    1998-05-08

    Speech is the predominant means of communication between human beings and since the invention of the telephone by Alexander Graham Bell in 1876, speech services have remained to be the core service in almost all telecommunication systems. Original analog methods of telephony had the disadvantage of speech signal getting corrupted by noise, cross-talk and distortion Long haul transmissions which use repeaters to compensate for the loss in signal strength on transmission links also increase the associated noise and distortion. On the other hand digital transmission is relatively immune to noise, cross-talk and distortion primarily because of the capability to faithfully regenerate digital signal at each repeater purely based on a binary decision. Hence end-to-end performance of the digital link essentially becomes independent of the length and operating frequency bands of the link Hence from a transmission point of view digital transmission has been the preferred approach due to its higher immunity to noise. The need to carry digital speech became extremely important from a service provision point of view as well. Modem requirements have introduced the need for robust, flexible and secure services that can carry a multitude of signal types (such as voice, data and video) without a fundamental change in infrastructure. Such a requirement could not have been easily met without the advent of digital transmission systems, thereby requiring speech to be coded digitally. The term Speech Coding is often referred to techniques that represent or code speech signals either directly as a waveform or as a set of parameters by analyzing the speech signal. In either case, the codes are transmitted to the distant end where speech is reconstructed or synthesized using the received set of codes. A more generic term that is applicable to these techniques that is often interchangeably used with speech coding is the term voice coding. This term is more generic in the sense that the

  20. Atemporal diagrams for quantum circuits

    SciTech Connect

    Griffiths, Robert B.; Wu Shengjun; Yu Li; Cohen, Scott M.

    2006-05-15

    A system of diagrams is introduced that allows the representation of various elements of a quantum circuit, including measurements, in a form which makes no reference to time (hence 'atemporal'). It can be used to relate quantum dynamical properties to those of entangled states (map-state duality), and suggests useful analogies, such as the inverse of an entangled ket. Diagrams clarify the role of channel kets, transition operators, dynamical operators (matrices), and Kraus rank for noisy quantum channels. Positive (semidefinite) operators are represented by diagrams with a symmetry that aids in understanding their connection with completely positive maps. The diagrams are used to analyze standard teleportation and dense coding, and for a careful study of unambiguous (conclusive) teleportation. A simple diagrammatic argument shows that a Kraus rank of 3 is impossible for a one-qubit channel modeled using a one-qubit environment in a mixed state.

  1. Sensor readout detector circuit

    DOEpatents

    Chu, D.D.; Thelen, D.C. Jr.

    1998-08-11

    A sensor readout detector circuit is disclosed that is capable of detecting sensor signals down to a few nanoamperes or less in a high (microampere) background noise level. The circuit operates at a very low standby power level and is triggerable by a sensor event signal that is above a predetermined threshold level. A plurality of sensor readout detector circuits can be formed on a substrate as an integrated circuit (IC). These circuits can operate to process data from an array of sensors in parallel, with only data from active sensors being processed for digitization and analysis. This allows the IC to operate at a low power level with a high data throughput for the active sensors. The circuit may be used with many different types of sensors, including photodetectors, capacitance sensors, chemically-sensitive sensors or combinations thereof to provide a capability for recording transient events or for recording data for a predetermined period of time following an event trigger. The sensor readout detector circuit has applications for portable or satellite-based sensor systems. 6 figs.

  2. Sensor readout detector circuit

    DOEpatents

    Chu, Dahlon D.; Thelen, Jr., Donald C.

    1998-01-01

    A sensor readout detector circuit is disclosed that is capable of detecting sensor signals down to a few nanoamperes or less in a high (microampere) background noise level. The circuit operates at a very low standby power level and is triggerable by a sensor event signal that is above a predetermined threshold level. A plurality of sensor readout detector circuits can be formed on a substrate as an integrated circuit (IC). These circuits can operate to process data from an array of sensors in parallel, with only data from active sensors being processed for digitization and analysis. This allows the IC to operate at a low power level with a high data throughput for the active sensors. The circuit may be used with many different types of sensors, including photodetectors, capacitance sensors, chemically-sensitive sensors or combinations thereof to provide a capability for recording transient events or for recording data for a predetermined period of time following an event trigger. The sensor readout detector circuit has applications for portable or satellite-based sensor systems.

  3. DIFFERENTIAL FAULT SENSING CIRCUIT

    DOEpatents

    Roberts, J.H.

    1961-09-01

    A differential fault sensing circuit is designed for detecting arcing in high-voltage vacuum tubes arranged in parallel. A circuit is provided which senses differences in voltages appearing between corresponding elements likely to fault. Sensitivity of the circuit is adjusted to some level above which arcing will cause detectable differences in voltage. For particular corresponding elements, a group of pulse transformers are connected in parallel with diodes connected across the secondaries thereof so that only voltage excursions are transmitted to a thyratron which is biased to the sensitivity level mentioned.

  4. Gallium Arsenide Domino Circuit

    NASA Technical Reports Server (NTRS)

    Yang, Long; Long, Stephen I.

    1990-01-01

    Advantages include reduced power and high speed. Experimental gallium arsenide field-effect-transistor (FET) domino circuit replicated in large numbers for use in dynamic-logic systems. Name of circuit denotes mode of operation, which logic signals propagate from each stage to next when successive stages operated at slightly staggered clock cycles, in manner reminiscent of dominoes falling in a row. Building block of domino circuit includes input, inverter, and level-shifting substages. Combinational logic executed in input substage. During low half of clock cycle, result of logic operation transmitted to following stage.

  5. Monolithic microwave integrated circuits

    NASA Astrophysics Data System (ADS)

    Pucel, R. A.

    Monolithic microwave integrated circuits (MMICs), a new microwave technology which is expected to exert a profound influence on microwave circuit designs for future military systems as well as for the commercial and consumer markets, is discussed. The book contains an historical discussion followed by a comprehensive review presenting the current status in the field. The general topics of the volume are: design considerations, materials and processing considerations, monolithic circuit applications, and CAD, measurement, and packaging techniques. All phases of MMIC technology are covered, from design to testing.

  6. Cell types, circuits, computation.

    PubMed

    Azeredo da Silveira, Rava; Roska, Botond

    2011-10-01

    How does the connectivity of a neuronal circuit, together with the individual properties of the cell types that take part in it, result in a given computation? We examine this question in the context of retinal circuits. We suggest that the retina can be viewed as a parallel assemblage of many small computational devices, highly stereotypical and task-specific circuits afferent to a given ganglion cell type, and we discuss some rules that govern computation in these devices. Multi-device processing in retina poses conceptual problems when it is contrasted with cortical processing. We lay out open questions both on processing in retinal circuits and on implications for cortical processing of retinal inputs.

  7. Code lock with microcircuit

    NASA Astrophysics Data System (ADS)

    Korobka, A.; May, I.

    1985-01-01

    A code lock with a microcircuit was invented which contains only a very few components. Two DD-triggers control the state of two identical transistors. When both transistors are turned on simultaneously the transistor VS1 is turned on so that the electromagnet YA1 pulls in the bolt and the door opens. This will happen only when a logic 1 appears at the inverted output of the first trigger and at the straight output of the second one. After the door is opened, a button on it resets the contactors to return both triggers to their original state. The electromagnetic is designed to produce the necessary pull force and sufficient power when under rectified 127 V line voltage, with the neutral wire of the lock circuit always connected to the - terminal of the power supply.

  8. QR Codes

    ERIC Educational Resources Information Center

    Lai, Hsin-Chih; Chang, Chun-Yen; Li, Wen-Shiane; Fan, Yu-Lin; Wu, Ying-Tien

    2013-01-01

    This study presents an m-learning method that incorporates Integrated Quick Response (QR) codes. This learning method not only achieves the objectives of outdoor education, but it also increases applications of Cognitive Theory of Multimedia Learning (CTML) (Mayer, 2001) in m-learning for practical use in a diverse range of outdoor locations. When…

  9. Power supply conditioning circuit

    NASA Technical Reports Server (NTRS)

    Primas, Lori E. (Inventor); Loveland, Rohan C. (Inventor)

    1988-01-01

    A conditioning circuit is provided with a constant current diode in series with a zener diode, the former having a high dynamic impedance and the latter a low dynamic impedance. The constant current diode can receive an input voltage with PARD. In conjunction with the zener diode fixed to a ground, a voltage divider is provided which can give an output voltage whose PARD was significantly reduced. The conditioning circuit is effective down to dc.

  10. Overriding Faulty Circuit Breakers

    NASA Technical Reports Server (NTRS)

    Robbins, Richard L.; Pierson, Thomas E.

    1987-01-01

    Retainer keeps power on in emergency. Simple mechanical device attaches to failed aircraft-type push/pull circuit breaker to restore electrical power temporarily until breaker replaced. Device holds push/pull button in closed position; unnecessary for crewmember to hold button in position by continual finger pressure. Sleeve and plug hold button in, overriding mechanical failure in circuit breaker. Windows in sleeve show button position.

  11. Minimal universal two-qubit controlled-NOT-based circuits

    SciTech Connect

    Shende, Vivek V.; Markov, Igor L.; Bullock, Stephen S.

    2004-06-01

    We give quantum circuits that simulate an arbitrary two-qubit unitary operator up to a global phase. For several quantum gate libraries we prove that gate counts are optimal in the worst and average cases. Our lower and upper bounds compare favorably to previously published results. Temporary storage is not used because it tends to be expensive in physical implementations. For each gate library, the best gate counts can be achieved by a single universal circuit. To compute the gate parameters in universal circuits, we use only closed-form algebraic expressions, and in particular do not rely on matrix exponentials. Our algorithm has been coded in C++.

  12. Vibration Damping Circuit Card Assembly

    NASA Technical Reports Server (NTRS)

    Hunt, Ronald Allen (Inventor)

    2016-01-01

    A vibration damping circuit card assembly includes a populated circuit card having a mass M. A closed metal container is coupled to a surface of the populated circuit card at approximately a geometric center of the populated circuit card. Tungsten balls fill approximately 90% of the metal container with a collective mass of the tungsten balls being approximately (0.07) M.

  13. Exchange circuits for FASTBUS slaves

    SciTech Connect

    Bratskii, A.A.; Matseev, M.Y.; Rybakov, V.G.

    1985-09-01

    This paper describes general-purpose circuits for FASTBUS interfacing of the functional part of a slave device. The circuits contain buffered receivers and transmitters, addressrecognition and data-transfer logic, and the required control/status registers. The described circuits are implemented with series-K500 integrated circuits.

  14. Circuit simulation: some humbling thoughts

    SciTech Connect

    Wendt, Manfred; /Fermilab

    2006-01-01

    A short, very personal note on circuit simulation is presented. It does neither include theoretical background on circuit simulation, nor offers an overview of available software, but just gives some general remarks for a discussion on circuit simulator needs in context to the design and development of accelerator beam instrumentation circuits and systems.

  15. Superconducting flux flow digital circuits

    DOEpatents

    Hietala, Vincent M.; Martens, Jon S.; Zipperian, Thomas E.

    1995-01-01

    A NOR/inverter logic gate circuit and a flip flop circuit implemented with superconducting flux flow transistors (SFFTs). Both circuits comprise two SFFTs with feedback lines. They have extremely low power dissipation, very high switching speeds, and the ability to interface between Josephson junction superconductor circuits and conventional microelectronics.

  16. Superconducting flux flow digital circuits

    DOEpatents

    Hietala, V.M.; Martens, J.S.; Zipperian, T.E.

    1995-02-14

    A NOR/inverter logic gate circuit and a flip flop circuit implemented with superconducting flux flow transistors (SFFTs) are disclosed. Both circuits comprise two SFFTs with feedback lines. They have extremely low power dissipation, very high switching speeds, and the ability to interface between Josephson junction superconductor circuits and conventional microelectronics. 8 figs.

  17. Identification coding schemes for modulated reflectance systems

    DOEpatents

    Coates, Don M.; Briles, Scott D.; Neagley, Daniel L.; Platts, David; Clark, David D.

    2006-08-22

    An identifying coding apparatus employing modulated reflectance technology involving a base station emitting a RF signal, with a tag, located remotely from the base station, and containing at least one antenna and predetermined other passive circuit components, receiving the RF signal and reflecting back to the base station a modulated signal indicative of characteristics related to the tag.

  18. Microfluidic serial dilution circuit.

    PubMed

    Paegel, Brian M; Grover, William H; Skelley, Alison M; Mathies, Richard A; Joyce, Gerald F

    2006-11-01

    In vitro evolution of RNA molecules requires a method for executing many consecutive serial dilutions. To solve this problem, a microfluidic circuit has been fabricated in a three-layer glass-PDMS-glass device. The 400-nL serial dilution circuit contains five integrated membrane valves: three two-way valves arranged in a loop to drive cyclic mixing of the diluent and carryover, and two bus valves to control fluidic access to the circuit through input and output channels. By varying the valve placement in the circuit, carryover fractions from 0.04 to 0.2 were obtained. Each dilution process, which is composed of a diluent flush cycle followed by a mixing cycle, is carried out with no pipeting, and a sample volume of 400 nL is sufficient for conducting an arbitrary number of serial dilutions. Mixing is precisely controlled by changing the cyclic pumping rate, with a minimum mixing time of 22 s. This microfluidic circuit is generally applicable for integrating automated serial dilution and sample preparation in almost any microfluidic architecture.

  19. Pulse Coded Biologically Motivated Neural-Type MOS Circuits

    DTIC Science & Technology

    1991-04-29

    a* • .. -SOMV + - -. 4 .---------------------..---------------- ..........- 4 ........... O.Os O.5s 1.0 1.5e 2.0s 2.5s 3 .Os Time Figure 2: PSPICE...a 0.06 . U 0 .5. 6 1.5, 2.04 2.5* 3.09 3 .U 4.06 Figure 4 (a): PSPICE simulation for 2 Figure 4 (b): PSPICE simulation for 2 DRIVERs with no coupling...ELECTE Professor RN/lc MAYO 91991 Enclosure: Semi-Annual Report ( 3 copies) cc: a) Researchers ft b) Dr. Alan Craig (1 copy) U AFOSR Bowling Air Force

  20. ELECTRONIC PHASE CONTROL CIRCUIT

    DOEpatents

    Salisbury, J.D.; Klein, W.W.; Hansen, C.F.

    1959-04-21

    An electronic circuit is described for controlling the phase of radio frequency energy applied to a multicavity linear accelerator. In one application of the circuit two cavities are excited from a single radio frequency source, with one cavity directly coupled to the source and the other cavity coupled through a delay line of special construction. A phase detector provides a bipolar d-c output signal proportional to the difference in phase between the voltage in the two cavities. This d-c signal controls a bias supply which provides a d-c output for varying the capacitnce of voltage sensitive capacitors in the delay line. The over-all operation of the circuit is completely electronic, overcoming the time response limitations of the electromechanical control systems, and the relative phase relationship of the radio frequency voltages in the two caviiies is continuously controlled to effect particle acceleration.

  1. ELECTRONIC TRIGGER CIRCUIT

    DOEpatents

    Russell, J.A.G.

    1958-01-01

    An electronic trigger circuit is described of the type where an output pulse is obtained only after an input voltage has cqualed or exceeded a selected reference voltage. In general, the invention comprises a source of direct current reference voltage in series with an impedance and a diode rectifying element. An input pulse of preselected amplitude causes the diode to conduct and develop a signal across the impedance. The signal is delivered to an amplifier where an output pulse is produced and part of the output is fed back in a positive manner to the diode so that the amplifier produces a steep wave front trigger pulsc at the output. The trigger point of the described circuit is not subject to variation due to the aging, etc., of multi-electrode tabes, since the diode circuit essentially determines the trigger point.

  2. ELECTRONIC MULTIPLIER CIRCUIT

    DOEpatents

    Thomas, R.E.

    1959-08-25

    An electronic multiplier circuit is described in which an output voltage having an amplitude proportional to the product or quotient of the input signals is accomplished in a novel manner which facilitates simplicity of circuit construction and a high degree of accuracy in accomplishing the multiplying and dividing function. The circuit broadly comprises a multiplier tube in which the plate current is proportional to the voltage applied to a first control grid multiplied by the difference between voltage applied to a second control grid and the voltage applied to the first control grid. Means are provided to apply a first signal to be multiplied to the first control grid together with means for applying the sum of the first signal to be multiplied and a second signal to be multiplied to the second control grid whereby the plate current of the multiplier tube is proportional to the product of the first and second signals to be multiplied.

  3. Electrical Circuit Tester

    DOEpatents

    Love, Frank

    2006-04-18

    An electrical circuit testing device is provided, comprising a case, a digital voltage level testing circuit with a display means, a switch to initiate measurement using the device, a non-shorting switching means for selecting pre-determined electrical wiring configurations to be tested in an outlet, a terminal block, a five-pole electrical plug mounted on the case surface and a set of adapters that can be used for various multiple-pronged electrical outlet configurations for voltages from 100 600 VAC from 50 100 Hz.

  4. Small circuits for cryptography.

    SciTech Connect

    Torgerson, Mark Dolan; Draelos, Timothy John; Schroeppel, Richard Crabtree; Miller, Russell D.; Anderson, William Erik

    2005-10-01

    This report examines a number of hardware circuit design issues associated with implementing certain functions in FPGA and ASIC technologies. Here we show circuit designs for AES and SHA-1 that have an extremely small hardware footprint, yet show reasonably good performance characteristics as compared to the state of the art designs found in the literature. Our AES performance numbers are fueled by an optimized composite field S-box design for the Stratix chipset. Our SHA-1 designs use register packing and feedback functionalities of the Stratix LE, which reduce the logic element usage by as much as 72% as compared to other SHA-1 designs.

  5. A rate-transparent, self-clocking line code

    NASA Technical Reports Server (NTRS)

    Prucnal, Paul R.; Perrier, Philippe A.

    1987-01-01

    A reliable and economical new transmission code is presented with the following properties: zero dc content, baseband bandwidth conservation, self-clocking capability, and data-rate-transparent decoding and synchronization. Simple encoder/decoder and clock extractor circuits are given. The code is demonstrated in a wavelength-multiplexed fiber-optic communication system.

  6. Integrated circuit reliability testing

    NASA Technical Reports Server (NTRS)

    Buehler, Martin G. (Inventor); Sayah, Hoshyar R. (Inventor)

    1990-01-01

    A technique is described for use in determining the reliability of microscopic conductors deposited on an uneven surface of an integrated circuit device. A wafer containing integrated circuit chips is formed with a test area having regions of different heights. At the time the conductors are formed on the chip areas of the wafer, an elongated serpentine assay conductor is deposited on the test area so the assay conductor extends over multiple steps between regions of different heights. Also, a first test conductor is deposited in the test area upon a uniform region of first height, and a second test conductor is deposited in the test area upon a uniform region of second height. The occurrence of high resistances at the steps between regions of different height is indicated by deriving the measured length of the serpentine conductor using the resistance measured between the ends of the serpentine conductor, and comparing that to the design length of the serpentine conductor. The percentage by which the measured length exceeds the design length, at which the integrated circuit will be discarded, depends on the required reliability of the integrated circuit.

  7. Integrated circuit reliability testing

    NASA Technical Reports Server (NTRS)

    Buehler, Martin G. (Inventor); Sayah, Hoshyar R. (Inventor)

    1988-01-01

    A technique is described for use in determining the reliability of microscopic conductors deposited on an uneven surface of an integrated circuit device. A wafer containing integrated circuit chips is formed with a test area having regions of different heights. At the time the conductors are formed on the chip areas of the wafer, an elongated serpentine assay conductor is deposited on the test area so the assay conductor extends over multiple steps between regions of different heights. Also, a first test conductor is deposited in the test area upon a uniform region of first height, and a second test conductor is deposited in the test area upon a uniform region of second height. The occurrence of high resistances at the steps between regions of different height is indicated by deriving the measured length of the serpentine conductor using the resistance measured between the ends of the serpentine conductor, and comparing that to the design length of the serpentine conductor. The percentage by which the measured length exceeds the design length, at which the integrated circuit will be discarded, depends on the required reliability of the integrated circuit.

  8. The Global Circuit.

    ERIC Educational Resources Information Center

    Lansford, Henry

    1983-01-01

    Discusses the nature of and research related to a theory explaining the earth's electric budget. The theory suggests a global electric circuit completed by a positive current flowing up into thunderstorm clouds, from clouds to ionosphere, distributed around the globe, and down to earth through the lower atmosphere in fair-weather regions. (JN)

  9. An atomtronic dumbell circuit

    NASA Astrophysics Data System (ADS)

    Li, Aijun; Murray, N.; Lanier, C.; Wang, Y.-H.; Clark, C. W.; Edwards, M.

    2014-05-01

    We report on simulations of the behavior of a Bose-Einstein condensate formed in the left well of a ``dumbell'' circuit potential. This quasi-2d potential takes the form of the combination of strong harmonic vertical confinement along with a horizontal-plane potential having dumbell shape. The dumbell consists of two circular wells connected by a channel. We assume that the condensate is initially formed in one of the wells and then is released and allowed to flow down the channel into the other well and possibly back again. We first simulated the behavior of the BEC in this potential using a variational mean-field version of the 3D Gross-Pitaevskii equation (GPE) at zero temperature for dumbell potentials having a range of different channel lengths and widths. We used these results to indentify equivalent ``atomtronic'' circuits such as an RCL circuit with DC battery. We also investigated the effects of finite temperature on the behavior of the condensate in the dumbell potential using the Zaremba-Nikuni-Griffin (ZNG) theory. These results were used to identify the effects of a thermal cloud on the atomtronic circuit operation. Supported in part by NSF grant #1068761 and ARO Atomtronics MURI.

  10. Wein bridge oscillator circuit

    NASA Technical Reports Server (NTRS)

    Lipoma, P. C.

    1971-01-01

    Circuit with minimum number of components provides stable outputs of 2 to 8 volts at frequencies of .001 to 100 kHz. Oscillator exhibits low power consumption, portability, simplicity, and drive capability, it has application as loudspeaker tester and audible alarm, as well as in laboratory and test generators.

  11. Circuit breaker lockout device

    DOEpatents

    Kozlowski, Lawrence J.; Shirey, Lawrence A.

    1992-01-01

    An improved lockout assembly for locking a circuit breaker in a selected off or on position is provided. The lockout assembly includes a lock block and a lock pin. The lock block has a hollow interior which fits over the free end of a switch handle of the circuit breaker. The lock block includes at least one hole that is placed in registration with a hole in the free end of the switch handle. A lock tab on the lock block serves to align and register the respective holes on the lock block and switch handle. A lock pin is inserted through the registered holes and serves to connect the lock block to the switch handle. Once the lock block and the switch handle are connected, the position of the switch handle is prevented from being changed by the lock tab bumping up against a stationary housing portion of the circuit breaker. When the lock pin installed, an apertured-end portion of the lock pin is in registration with another hole on the lock block. Then a special scissors conforming to O.S.H.A. regulations can be installed, with one or more padlocks, on the lockout assembly to prevent removal of the lock pin from the lockout assembly, thereby preventing removal of the lockout assembly from the circuit breaker.

  12. Circuit breaker lockout device

    DOEpatents

    Kozlowski, L.J.; Shirey, L.A.

    1992-11-24

    An improved lockout assembly for locking a circuit breaker in a selected off or on position is provided. The lockout assembly includes a lock block and a lock pin. The lock block has a hollow interior which fits over the free end of a switch handle of the circuit breaker. The lock block includes at least one hole that is placed in registration with a hole in the free end of the switch handle. A lock tab on the lock block serves to align and register the respective holes on the lock block and switch handle. A lock pin is inserted through the registered holes and serves to connect the lock block to the switch handle. Once the lock block and the switch handle are connected, the position of the switch handle is prevented from being changed by the lock tab bumping up against a stationary housing portion of the circuit breaker. When the lock pin installed, an apertured-end portion of the lock pin is in registration with another hole on the lock block. Then a special scissors conforming to O.S.H.A. regulations can be installed, with one or more padlocks, on the lockout assembly to prevent removal of the lock pin from the lockout assembly, thereby preventing removal of the lockout assembly from the circuit breaker. 2 figs.

  13. Bioluminescent bioreporter integrated circuit

    DOEpatents

    Simpson, Michael L.; Sayler, Gary S.; Paulus, Michael J.

    2000-01-01

    Disclosed are monolithic bioelectronic devices comprising a bioreporter and an OASIC. These bioluminescent bioreporter integrated circuit are useful in detecting substances such as pollutants, explosives, and heavy-metals residing in inhospitable areas such as groundwater, industrial process vessels, and battlefields. Also disclosed are methods and apparatus for environmental pollutant detection, oil exploration, drug discovery, industrial process control, and hazardous chemical monitoring.

  14. A Step Circuit Program.

    ERIC Educational Resources Information Center

    Herman, Susan

    1995-01-01

    Aerobics instructors can use step aerobics to motivate students. One creative method is to add the step to the circuit workout. By incorporating the step, aerobic instructors can accommodate various fitness levels. The article explains necessary equipment and procedures, describing sample stations for cardiorespiratory fitness, muscular strength,…

  15. A Magnetic Circuit Demonstration.

    ERIC Educational Resources Information Center

    Vanderkooy, John; Lowe, June

    1995-01-01

    Presents a demonstration designed to illustrate Faraday's, Ampere's, and Lenz's laws and to reinforce the concepts through the analysis of a two-loop magnetic circuit. Can be made dramatic and challenging for sophisticated students but is suitable for an introductory course in electricity and magnetism. (JRH)

  16. Field circuit breaker tester

    NASA Astrophysics Data System (ADS)

    Fulcomer, P. M.

    1982-05-01

    Test equipment developed at National Bureau of Standards (NBS) for the Consumer Product Safety Commission (CPSC) to evaluate the performance of single-pole circuit breakers in residential installations is described along with instructions for its use. The procedures are intended to be carried out by a test crew of at least two persons.

  17. "Printed-circuit" rectenna

    NASA Technical Reports Server (NTRS)

    Dickinson, R. M.

    1977-01-01

    Rectifying antenna is less bulky structure for absorbing transmitted microwave power and converting it into electrical current. Printed-circuit approach, using microstrip technology and circularly polarized antenna, makes polarization orientation unimportant and allows much smaller arrays for given performance. Innovation is particularly useful with proposed electric vehicles powered by beam microwaves.

  18. Electrifying Inquiry: Electrical Circuits

    ERIC Educational Resources Information Center

    Godbey, Susan; Barnett, Jessica; Webster, Lois

    2005-01-01

    An activity involving parallel electrical circuits was modified to incorporate an open inquiry approach. Both the original and revised versions of the activity were tested in the middle school classroom. We present a comparison of the two versions of the activity in terms of facilitating learning and engaging students' interests.

  19. Resistor Combinations for Parallel Circuits.

    ERIC Educational Resources Information Center

    McTernan, James P.

    1978-01-01

    To help simplify both teaching and learning of parallel circuits, a high school electricity/electronics teacher presents and illustrates the use of tables of values for parallel resistive circuits in which total resistances are whole numbers. (MF)

  20. Automatic Parametric Testing Of Integrated Circuits

    NASA Technical Reports Server (NTRS)

    Jennings, Glenn A.; Pina, Cesar A.

    1989-01-01

    Computer program for parametric testing saves time and effort in research and development of integrated circuits. Software system automatically assembles various types of test structures and lays them out on silicon chip, generates sequency of test instructions, and interprets test data. Employs self-programming software; needs minimum of human intervention. Adapted to needs of different laboratories and readily accommodates new test structures. Program codes designed to be adaptable to most computers and test equipment now in use. Written in high-level languages to enhance transportability.

  1. Electronic circuits and systems: A compilation. [including integrated circuits, logic circuits, varactor diode circuits, low pass filters, and optical equipment circuits

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Technological information is presented electronic circuits and systems which have potential utility outside the aerospace community. Topics discussed include circuit components such as filters, converters, and integrators, circuits designed for use with specific equipment or systems, and circuits designed primarily for use with optical equipment or displays.

  2. Improved Classical Simulation of Quantum Circuits Dominated by Clifford Gates.

    PubMed

    Bravyi, Sergey; Gosset, David

    2016-06-24

    We present a new algorithm for classical simulation of quantum circuits over the Clifford+T gate set. The runtime of the algorithm is polynomial in the number of qubits and the number of Clifford gates in the circuit but exponential in the number of T gates. The exponential scaling is sufficiently mild that the algorithm can be used in practice to simulate medium-sized quantum circuits dominated by Clifford gates. The first demonstrations of fault-tolerant quantum circuits based on 2D topological codes are likely to be dominated by Clifford gates due to a high implementation cost associated with logical T gates. Thus our algorithm may serve as a verification tool for near-term quantum computers which cannot in practice be simulated by other means. To demonstrate the power of the new method, we performed a classical simulation of a hidden shift quantum algorithm with 40 qubits, a few hundred Clifford gates, and nearly 50 T gates.

  3. Methods of fabricating applique circuits

    DOEpatents

    Dimos, Duane B.; Garino, Terry J.

    1999-09-14

    Applique circuits suitable for advanced packaging applications are introduced. These structures are particularly suited for the simple integration of large amounts (many nanoFarads) of capacitance into conventional integrated circuit and multichip packaging technology. In operation, applique circuits are bonded to the integrated circuit or other appropriate structure at the point where the capacitance is required, thereby minimizing the effects of parasitic coupling. An immediate application is to problems of noise reduction and control in modern high-frequency circuitry.

  4. Statistical circuit design for yield improvement in CMOS circuits

    NASA Technical Reports Server (NTRS)

    Kamath, H. J.; Purviance, J. E.; Whitaker, S. R.

    1990-01-01

    This paper addresses the statistical design of CMOS integrated circuits for improved parametric yield. The work uses the Monte Carlo technique of circuit simulation to obtain an unbiased estimation of the yield. A simple graphical analysis tool, the yield factor histogram, is presented. The yield factor histograms are generated by a new computer program called SPICENTER. Using the yield factor histograms, the most sensitive circuit parameters are noted, and their nominal values are changed to improve the yield. Two basic CMOS example circuits, one analog and one digital, are chosen and their designs are 'centered' to illustrate the use of the yield factor histograms for statistical circuit design.

  5. Ladder-Type Circuits Revisited

    ERIC Educational Resources Information Center

    Yoon, Sung Hyun

    2007-01-01

    Ladder-type circuits where a given unit is repeated infinitely many times are dealt with in many textbooks on electromagnetism as examples of filter circuits. Determining the impedance of such circuits seems to be regarded as simple, which may be due to the fact that the invariance of the infinite system under the operation of adding one more unit…

  6. High voltage MOSFET switching circuit

    DOEpatents

    McEwan, T.E.

    1994-07-26

    The problem of source lead inductance in a MOSFET switching circuit is compensated for by adding an inductor to the gate circuit. The gate circuit inductor produces an inductive spike which counters the source lead inductive drop to produce a rectangular drive voltage waveform at the internal gate-source terminals of the MOSFET. 2 figs.

  7. High voltage MOSFET switching circuit

    DOEpatents

    McEwan, Thomas E.

    1994-01-01

    The problem of source lead inductance in a MOSFET switching circuit is compensated for by adding an inductor to the gate circuit. The gate circuit inductor produces an inductive spike which counters the source lead inductive drop to produce a rectangular drive voltage waveform at the internal gate-source terminals of the MOSFET.

  8. Selective Manipulation of Neural Circuits.

    PubMed

    Park, Hong Geun; Carmel, Jason B

    2016-04-01

    Unraveling the complex network of neural circuits that form the nervous system demands tools that can manipulate specific circuits. The recent evolution of genetic tools to target neural circuits allows an unprecedented precision in elucidating their function. Here we describe two general approaches for achieving circuit specificity. The first uses the genetic identity of a cell, such as a transcription factor unique to a circuit, to drive expression of a molecule that can manipulate cell function. The second uses the spatial connectivity of a circuit to achieve specificity: one genetic element is introduced at the origin of a circuit and the other at its termination. When the two genetic elements combine within a neuron, they can alter its function. These two general approaches can be combined to allow manipulation of neurons with a specific genetic identity by introducing a regulatory gene into the origin or termination of the circuit. We consider the advantages and disadvantages of both these general approaches with regard to specificity and efficacy of the manipulations. We also review the genetic techniques that allow gain- and loss-of-function within specific neural circuits. These approaches introduce light-sensitive channels (optogenetic) or drug sensitive channels (chemogenetic) into neurons that form specific circuits. We compare these tools with others developed for circuit-specific manipulation and describe the advantages of each. Finally, we discuss how these tools might be applied for identification of the neural circuits that mediate behavior and for repair of neural connections.

  9. Error-correction coding

    NASA Technical Reports Server (NTRS)

    Hinds, Erold W. (Principal Investigator)

    1996-01-01

    This report describes the progress made towards the completion of a specific task on error-correcting coding. The proposed research consisted of investigating the use of modulation block codes as the inner code of a concatenated coding system in order to improve the overall space link communications performance. The study proposed to identify and analyze candidate codes that will complement the performance of the overall coding system which uses the interleaved RS (255,223) code as the outer code.

  10. Neuromorphic Silicon Neuron Circuits

    PubMed Central

    Indiveri, Giacomo; Linares-Barranco, Bernabé; Hamilton, Tara Julia; van Schaik, André; Etienne-Cummings, Ralph; Delbruck, Tobi; Liu, Shih-Chii; Dudek, Piotr; Häfliger, Philipp; Renaud, Sylvie; Schemmel, Johannes; Cauwenberghs, Gert; Arthur, John; Hynna, Kai; Folowosele, Fopefolu; Saighi, Sylvain; Serrano-Gotarredona, Teresa; Wijekoon, Jayawan; Wang, Yingxue; Boahen, Kwabena

    2011-01-01

    Hardware implementations of spiking neurons can be extremely useful for a large variety of applications, ranging from high-speed modeling of large-scale neural systems to real-time behaving systems, to bidirectional brain–machine interfaces. The specific circuit solutions used to implement silicon neurons depend on the application requirements. In this paper we describe the most common building blocks and techniques used to implement these circuits, and present an overview of a wide range of neuromorphic silicon neurons, which implement different computational models, ranging from biophysically realistic and conductance-based Hodgkin–Huxley models to bi-dimensional generalized adaptive integrate and fire models. We compare the different design methodologies used for each silicon neuron design described, and demonstrate their features with experimental results, measured from a wide range of fabricated VLSI chips. PMID:21747754

  11. PHASE DIFFERENTIAL INDICATING CIRCUIT

    DOEpatents

    Kirsten, F.A.

    1962-01-01

    An electronic circuit for totalizing the net phase difference between two alternating current signals is designed which responds to both increasing and decreasing phase changes. A phase comparator provldes an output pulse for each 360 deg of phase difference occurring, there being a negative pulse for phase shtft in one direction and a positive pulse for a phase shift in the opposite direction. A counting circuit utilizing glow discharge tubes receives the negative and positive pulses at a single input terminal and provides a running net total, pulses of one polarity dded and pulses of the opposite polarity being subtracted. The glow discharge tubes may be decaded to increase the total count capacity. (AEC)

  12. Power supply conditioning circuit

    NASA Technical Reports Server (NTRS)

    Primas, L. E.; Loveland, R.

    1987-01-01

    A power supply conditioning circuit that can reduce Periodic and Random Deviations (PARD) on the output voltages of dc power supplies to -150 dBV from dc to several KHz with no measurable periodic deviations is described. The PARD for a typical commercial low noise power supply is -74 dBV for frequencies above 20 Hz and is often much worse at frequencies below 20 Hz. The power supply conditioning circuit described here relies on the large differences in the dynamic impedances of a constant current diode and a zener diode to establish a dc voltage with low PARD. Power supplies with low PARD are especially important in circuitry involving ultrastable frequencies for the Deep Space Network.

  13. GAS PHOTOTUBE CIRCUIT

    DOEpatents

    Richardson, J.H.

    1958-03-01

    This patent pertains to electronic circuits for measuring the intensity of light and is especially concerned with measurement between preset light thresholds. Such a circuit has application in connection with devices for reading-out information stored on punch cards or tapes where the cards and tapes are translucent. By the novel arrangement of this invention thc sensitivity of a gas phototube is maintained at a low value when the light intensity is below a first threshold level. If the light level rises above the first threshold level, the tube is rendered highly sensitive and an output signal will vary in proportion to the light intensity change. When the light level decreases below a second threshold level, the gas phototube is automatically rendered highly insensitive. Each of these threshold points is adjustable.

  14. Preconditioner Circuit Analysis

    DTIC Science & Technology

    2011-09-01

    ground plane and both operational amplifier terminals. The parasitic capacitances are labeled Cp1 and Cp2 in Figure 19. Figure 19. Circuit for...3.69 MHz 3.98pF 55720 5107 OV                                  (17) Cp2 = 1 pF R1 = 5107 Ω R3...circuit. The capacitor would be placed in parallel with RF to cancel the effect of Cp2 and then feedback factor will look purely resistive. Another

  15. Integrated Circuit Immunity

    NASA Technical Reports Server (NTRS)

    Sketoe, J. G.; Clark, Anthony

    2000-01-01

    This paper presents a DOD E3 program overview on integrated circuit immunity. The topics include: 1) EMI Immunity Testing; 2) Threshold Definition; 3) Bias Tee Function; 4) Bias Tee Calibration Set-Up; 5) EDM Test Figure; 6) EMI Immunity Levels; 7) NAND vs. and Gate Immunity; 8) TTL vs. LS Immunity Levels; 9) TP vs. OC Immunity Levels; 10) 7805 Volt Reg Immunity; and 11) Seventies Chip Set. This paper is presented in viewgraph form.

  16. Monolithic Optoelectronic Integrated Circuit

    NASA Technical Reports Server (NTRS)

    Bhasin, Kul B.; Walters, Wayne; Gustafsen, Jerry; Bendett, Mark

    1990-01-01

    Monolithic optoelectronic integrated circuit (OEIC) receives single digitally modulated input light signal via optical fiber and converts it into 16-channel electrical output signal. Potentially useful in any system in which digital data must be transmitted serially at high rates, then decoded into and used in parallel format at destination. Applications include transmission and decoding of control signals to phase shifters in phased-array antennas and also communication of data between computers and peripheral equipment in local-area networks.

  17. Cartography of serotonergic circuits.

    PubMed

    Sparta, Dennis R; Stuber, Garret D

    2014-08-06

    Serotonin is an essential neuromodulator, but the precise circuit connectivity that regulates serotonergic neurons has not been well defined. Using rabies virus tracing strategies Weissbourd et al. (2014) and Pollak Dorocic et al. (2014) in this issue of Neuron and Ogawa et al. (2014) in Cell Reports provide a comprehensive map of the inputs to serotonergic neurons, highlighting the complexity and diversity of potential upstream cellular regulators.

  18. PARTICLE BEAM TRACKING CIRCUIT

    DOEpatents

    Anderson, O.A.

    1959-05-01

    >A particle-beam tracking and correcting circuit is described. Beam induction electrodes are placed on either side of the beam, and potentials induced by the beam are compared in a voltage comparator or discriminator. This comparison produces an error signal which modifies the fm curve at the voltage applied to the drift tube, thereby returning the orbit to the preferred position. The arrangement serves also to synchronize accelerating frequency and magnetic field growth. (T.R.H.)

  19. Driven superconducting quantum circuits

    NASA Astrophysics Data System (ADS)

    Nakamura, Yasunobu

    2014-03-01

    Driven nonlinear quantum systems show rich phenomena in various fields of physics. Among them, superconducting quantum circuits have very attractive features such as well-controlled quantum states with design flexibility, strong nonlinearity of Josephson junctions, strong coupling to electromagnetic driving fields, little internal dissipation, and tailored coupling to the electromagnetic environment. We have investigated properties and functionalities of driven superconducting quantum circuits. A transmon qubit coupled to a transmission line shows nearly perfect spatial mode matching between the incident and scattered microwave field in the 1D mode. Dressed states under a driving field are studied there and also in a semi-infinite 1D mode terminated by a resonator containing a flux qubit. An effective Λ-type three-level system is realized under an appropriate driving condition. It allows ``impedance-matched'' perfect absorption of incident probe photons and down conversion into another frequency mode. Finally, the weak signal from the qubit is read out using a Josephson parametric amplifier/oscillator which is another nonlinear circuit driven by a strong pump field. This work was partly supported by the Funding Program for World-Leading Innovative R&D on Science and Technology (FIRST), Project for Developing Innovation Systems of MEXT, MEXT KAKENHI ``Quantum Cybernetics,'' and the NICT Commissioned Research.

  20. Digital integrated circuits

    NASA Astrophysics Data System (ADS)

    Polasek, P.; Halamik, J.

    1984-05-01

    The term semicustom designed integrated circuits denotes integrated circuits of an all purpose character in which the production of chips is completed by using one to three custom design stencil type exposure masks. This involves in most cases interconnecting masks that are used to devise the circuit function desired by the customer. Silicon plates with an all purpose gate matrix are produced up to the interconnection level and can be kept at this phase in storage, after which a customer's specific demands can be met very expediently. All purpose logic fields containing 200 logic gates on a chip and an all purpose chip to be expanded to 1,000 logic gates are discussed. The technology facilitates the devising of fast gates with a delay of approximately 5 ns and power dissipation of 1 mW. In assembly it will be possible to make use of the entire assortment of the currently used casings with 16, 18, 20, 24, 28 and 40 outlets. In addition to the development of the mentioned technology, a general methodology for design of the mentioned gate fields is currently under way.

  1. Optical Circuit Switched Protocol

    NASA Technical Reports Server (NTRS)

    Monacos, Steve P. (Inventor)

    2000-01-01

    The present invention is a system and method embodied in an optical circuit switched protocol for the transmission of data through a network. The optical circuit switched protocol is an all-optical circuit switched network and includes novel optical switching nodes for transmitting optical data packets within a network. Each optical switching node comprises a detector for receiving the header, header detection logic for translating the header into routing information and eliminating the header, and a controller for receiving the routing information and configuring an all optical path within the node. The all optical path located within the node is solely an optical path without having electronic storage of the data and without having optical delay of the data. Since electronic storage of the header is not necessary and the initial header is eliminated by the first detector of the first switching node. multiple identical headers are sent throughout the network so that subsequent switching nodes can receive and read the header for setting up an optical data path.

  2. Inkjet deposited circuit components

    NASA Astrophysics Data System (ADS)

    Bidoki, S. M.; Nouri, J.; Heidari, A. A.

    2010-05-01

    All-printed electronics as a means of achieving ultra-low-cost electronic circuits has attracted great interest in recent years. Inkjet printing is one of the most promising techniques by which the circuit components can be ultimately drawn (i.e. printed) onto the substrate in one step. Here, the inkjet printing technique was used to chemically deposit silver nanoparticles (10-200 nm) simply by ejection of silver nitrate and reducing solutions onto different substrates such as paper, PET plastic film and textile fabrics. The silver patterns were tested for their functionality to work as circuit components like conductor, resistor, capacitor and inductor. Different levels of conductivity were achieved simply by changing the printing sequence, inks ratio and concentration. The highest level of conductivity achieved by an office thermal inkjet printer (300 dpi) was 5.54 × 105 S m-1 on paper. Inkjet deposited capacitors could exhibit a capacitance of more than 1.5 nF (parallel plate 45 × 45 mm2) and induction coils displayed an inductance of around 400 µH (planar coil 10 cm in diameter). Comparison of electronic performance of inkjet deposited components to the performance of conventionally etched items makes the technique highly promising for fabricating different printed electronic devices.

  3. Interface Circuit For Printer Port

    NASA Technical Reports Server (NTRS)

    Tucker, Jerry H.; Yadlowsky, Ann B.

    1991-01-01

    Electronic circuit, called printer-port interface circuit (PPI) developed to overcome certain disadvantages of previous methods for connecting IBM PC or PC-compatible computer to other equipment. Has both reading and writing modes of operation. Very simple, requiring only six integrated circuits. Provides for moderately fast rates of transfer of data and uses existing unmodified circuit card in IBM PC. When used with appropriate software, circuit converts printer port on IBM PC, XT, AT, or compatible personal computer to general purpose, 8-bit-data, 16-bit address bus that connects to multitude of devices.

  4. Coating Circuit Boards With Silicone

    NASA Technical Reports Server (NTRS)

    Gaudiano, S.

    1986-01-01

    Techniques appropriate to boards containing CMOS circuits detailed. Document presents procedure for applying thin conformal coating to such electronic assemblies as printed-circuit boards and wire-wrapped boards. Coating is from 1 to 7 mils (25 to 178 micrometers) thick and composed of room-temperature-vulcanizing (RTV) silicone. Specifies materials, equipment, spraying method, and quality requirements. Takes into account special needs of circuits made with complementary metal-oxide/semiconductor (CMOS) devices on circuit boards. Special attention given to preventing damage by electrostatic discharge, to which CMOS circuits especially sensitive.

  5. Power system with an integrated lubrication circuit

    SciTech Connect

    Hoff, Brian D.; Akasam, Sivaprasad; Algrain, Marcelo C.; Johnson, Kris W.; Lane, William H.

    2009-11-10

    A power system includes an engine having a first lubrication circuit and at least one auxiliary power unit having a second lubrication circuit. The first lubrication circuit is in fluid communication with the second lubrication circuit.

  6. Circuit quantum electrodynamics

    NASA Astrophysics Data System (ADS)

    Bishop, Lev Samuel

    Circuit Quantum Electrodynamics (cQED), the study of the interaction between superconducting circuits behaving as artificial atoms and 1-dimensional transmission-line resonators, has shown much promise for quantum information processing tasks. For the purposes of quantum computing it is usual to approximate the artificial atoms as 2-level qubits, and much effort has been expended on attempts to isolate these qubits from the environment and to invent ever more sophisticated control and measurement schemes. Rather than focussing on these technological aspects of the field, this thesis investigates the opportunities for using these carefully engineered systems for answering questions of fundamental physics. The low dissipation and small mode volume of the circuits allows easy access to the strong-coupling regime of quantum optics, where one can investigate the interaction of light and matter at the level of single atoms and photons. A signature of strong coupling is the splitting of the cavity transmission peak into a pair of resolvable peaks when a single resonant atom is placed inside the cavity---an effect known as vacuum Rabi splitting. The cQED architecture is ideally suited for going beyond this linear response effect. This thesis shows that increasing the drive power results in two unique nonlinear features in the transmitted heterodyne signal: the supersplitting of each vacuum Rabi peak into a doublet, and the appearance of additional peaks with the characteristic n spacing of the Jaynes-Cummings ladder. These constitute direct evidence for the coupling between the quantized microwave field and the anharmonic spectrum of a superconducting qubit acting as an artificial atom. This thesis also addresses the idea of Bell tests, which are experiments that aim to disprove certain types of classical theories, presenting a proposed method for preparing maximally entangled 3-qubit states via a 'preparation by measurement' scheme using an optimized filter on the time

  7. Optically controllable molecular logic circuits

    SciTech Connect

    Nishimura, Takahiro Fujii, Ryo; Ogura, Yusuke; Tanida, Jun

    2015-07-06

    Molecular logic circuits represent a promising technology for observation and manipulation of biological systems at the molecular level. However, the implementation of molecular logic circuits for temporal and programmable operation remains challenging. In this paper, we demonstrate an optically controllable logic circuit that uses fluorescence resonance energy transfer (FRET) for signaling. The FRET-based signaling process is modulated by both molecular and optical inputs. Based on the distance dependence of FRET, the FRET pathways required to execute molecular logic operations are formed on a DNA nanostructure as a circuit based on its molecular inputs. In addition, the FRET pathways on the DNA nanostructure are controlled optically, using photoswitching fluorescent molecules to instruct the execution of the desired operation and the related timings. The behavior of the circuit can thus be controlled using external optical signals. As an example, a molecular logic circuit capable of executing two different logic operations was studied. The circuit contains functional DNAs and a DNA scaffold to construct two FRET routes for executing Input 1 AND Input 2 and Input 1 AND NOT Input 3 operations on molecular inputs. The circuit produced the correct outputs with all possible combinations of the inputs by following the light signals. Moreover, the operation execution timings were controlled based on light irradiation and the circuit responded to time-dependent inputs. The experimental results demonstrate that the circuit changes the output for the required operations following the input of temporal light signals.

  8. Integrated circuit cell library

    NASA Technical Reports Server (NTRS)

    Whitaker, Sterling R. (Inventor); Miles, Lowell H. (Inventor)

    2005-01-01

    According to the invention, an ASIC cell library for use in creation of custom integrated circuits is disclosed. The ASIC cell library includes some first cells and some second cells. Each of the second cells includes two or more kernel cells. The ASIC cell library is at least 5% comprised of second cells. In various embodiments, the ASIC cell library could be 10% or more, 20% or more, 30% or more, 40% or more, 50% or more, 60% or more, 70% or more, 80% or more, 90% or more, or 95% or more comprised of second cells.

  9. Base drive circuit

    DOEpatents

    Lange, Arnold C.

    1995-01-01

    An improved base drive circuit (10) having a level shifter (24) for providing bistable input signals to a pair of non-linear delays (30, 32). The non-linear delays (30, 32) provide gate control to a corresponding pair of field effect transistors (100, 106) through a corresponding pair of buffer components (88, 94). The non-linear delays (30, 32) provide delayed turn-on for each of the field effect transistors (100, 106) while an associated pair of transistors (72, 80) shunt the non-linear delays (30, 32) during turn-off of the associated field effect transistor (100, 106).

  10. Temperature-Controlling Circuit

    NASA Technical Reports Server (NTRS)

    Temple, Gerald

    1987-01-01

    Simple circuit switches current to electrical heater on and off to maintain temperature of room at 25 plus or minus 0.5 degree C. Lightweight, compact, reliable, insensitive to electrical noise, and uses single 5-Vdc power supply. Handles ac loads of 10 A. Designed to operate outside temperature controlled environment over range of -55 to +85 degree C. Thermistor provides input signal for simple temperature controller. Output of controller applied to solid-state relay, which in turn switches current to resistance heater.

  11. Distributed circuit switching starnet

    SciTech Connect

    Chuan-lin Wu; Woei Lin; Min-chang Lin

    1982-01-01

    Starnet is a communication subnet which can cost-effectively connect hundreds or thousands of processors for distributed processing. It uses distributed control and circuit switching. Starnet's communication medium includes two major components: a multistage interconnection network and a set of interface units. The interconnection network uses a destination routing scheme with no central control. The interface unit provides handshaking between the computer/data node and the interconnection network under the control of a microprocessor. Detailed design of the communication medium is described. A model for comparing cost-effectiveness among starnet, crossbar and multiple buses is included. 7 references.

  12. Small Depth Quantum Circuits

    DTIC Science & Technology

    2007-01-01

    circuit families and quantum Turing machines”. Theoretical Computer Science, 1-2(276):147–181, 2002. [20] S. Parker and M . B . Plenio . “Efficient...unclassified b . ABSTRACT unclassified c. THIS PAGE unclassified Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 polynomial-size...xn, b 〉 = |x1, ..., xn, b ⊕ f(x1, . . . , xn)〉 This is just an easy form of simulating any classical function in a reversible manner. If f(x1

  13. Itch Mechanisms and Circuits

    PubMed Central

    Han, Liang; Dong, Xinzhong

    2014-01-01

    The itch-scratch reflex serves as a protective mechanism in everyday life. However, chronic persistent itching can be devastating. Despite the clinical importance of the itch sensation, its mechanism remains elusive. In the past decade, substantial progress has been made to uncover the mystery of itching. Here, we review the molecules, cells, and circuits known to mediate the itch sensation, which, coupled with advances in understanding the pathophysiology of chronic itching conditions, will hopefully contribute to the development of new anti-itch therapies. PMID:24819620

  14. Seeing Circuits Assemble

    PubMed Central

    Lichtman, Jeff W.; Smith, Stephen J.

    2009-01-01

    Developmental neurobiology has been greatly invigorated by a recent string of breakthroughs in molecular biology and optical physics that permit direct in vivo observation of neural circuit assembly. The imaging done thus far suggests that as brains are built, a significant amount of unbuilding is also occurring. We offer the view that this tumult is the result of the intersecting behaviors of the many single-celled creatures (i.e., neurons, glia, and progenitors) that inhabit brains. New tools will certainly be needed if we wish to monitor the myriad cooperative and competitive interactions at play in the cellular society that builds brains. PMID:18995818

  15. Photonic Integrated Circuits

    NASA Technical Reports Server (NTRS)

    Merritt, Scott; Krainak, Michael

    2016-01-01

    Integrated photonics generally is the integration of multiple lithographically defined photonic and electronic components and devices (e.g. lasers, detectors, waveguides passive structures, modulators, electronic control and optical interconnects) on a single platform with nanometer-scale feature sizes. The development of photonic integrated circuits permits size, weight, power and cost reductions for spacecraft microprocessors, optical communication, processor buses, advanced data processing, and integrated optic science instrument optical systems, subsystems and components. This is particularly critical for small spacecraft platforms. We will give an overview of some NASA applications for integrated photonics.

  16. Dynamic pulse difference circuit

    DOEpatents

    Erickson, Gerald L.

    1978-01-01

    A digital electronic circuit of especial use for subtracting background activity pulses in gamma spectrometry comprises an up-down counter connected to count up with signal-channel pulses and to count down with background-channel pulses. A detector responsive to the count position of the up-down counter provides a signal when the up-down counter has completed one scaling sequence cycle of counts in the up direction. In an alternate embodiment, a detector responsive to the count position of the up-down counter provides a signal upon overflow of the counter.

  17. Signal Processing Circuit Development.

    DTIC Science & Technology

    1986-07-01

    Simplified active filter circuit 64 42. Video output amplifier 66 43. 64/128 gated clock circuitry 68 44. Two pole Sallen-Key active filters 7!1 45. Switched...four quadrant multiplier, log compression, multiple pole active video filtering and black level control. In what follows in this report an attempt...chip is shown in Fiqu-e 5. This is the master synch chip which generates all of the control signals necessary for TV monitor presentation of video data

  18. Base drive circuit

    DOEpatents

    Lange, A.C.

    1995-04-04

    An improved base drive circuit having a level shifter for providing bistable input signals to a pair of non-linear delays. The non-linear delays provide gate control to a corresponding pair of field effect transistors through a corresponding pair of buffer components. The non-linear delays provide delayed turn-on for each of the field effect transistors while an associated pair of transistors shunt the non-linear delays during turn-off of the associated field effect transistor. 2 figures.

  19. Sequential circuit design for radiation hardened multiple voltage integrated circuits

    SciTech Connect

    Clark, Lawrence T.; McIver, III, John K.

    2009-11-24

    The present invention includes a radiation hardened sequential circuit, such as a bistable circuit, flip-flop or other suitable design that presents substantial immunity to ionizing radiation while simultaneously maintaining a low operating voltage. In one embodiment, the circuit includes a plurality of logic elements that operate on relatively low voltage, and a master and slave latches each having storage elements that operate on a relatively high voltage.

  20. Identified circuit in rat postrhinal cortex encodes essential information for performing specific visual shape discriminations.

    PubMed

    Zhang, Guo-rong; Cao, Haiyan; Kong, Lingxin; O'Brien, Jennifer; Baughns, Andrew; Jan, Mary; Zhao, Hua; Wang, Xiaodan; Lu, Xiu-gui; Cook, Robert G; Geller, Alfred I

    2010-08-10

    Learning theories hypothesize specific circuits encode essential information for performance. For simple tasks in invertebrates and mammals, the essential circuits are known, but for cognitive functions, the essential circuits remain unidentified. Here, we show that some essential information for performing a choice task is encoded in a specific circuit in a neocortical area. Rat postrhinal (POR) cortex is required for visual shape discriminations, protein kinase C (PKC) pathways mediate changes in neuronal physiology that support learning, and specific PKC genes are required for multiple learning tasks. We used direct gene transfer of a constitutively active PKC to prime a specific POR cortex circuit for learning visual shape discriminations. In the experiment, rats learned a discrimination, received gene transfer, learned new discriminations, received a small lesion that ablated approximately 21% of POR cortex surrounding the gene transfer site, and were tested for performance for discriminations learned either before or after gene transfer. Lesions of the genetically targeted circuit selectively interfered with performance for discriminations learned after gene transfer. Activity-dependent gene imaging confirmed increased activity in the genetically targeted circuit during learning and showed the essential information was sparse-coded in approximately 500 neurons in the lesioned area. Wild-type rats contained circuits with similar increases in activity during learning, but these circuits were located at unpredictable, different positions in POR cortex. These results establish that some essential information for performing specific visual discriminations can be encoded in a small, identified, neocortical circuit and provide a foundation for characterizing the circuit and essential information.

  1. Add/Compare/Select Circuit For Rapid Decoding

    NASA Technical Reports Server (NTRS)

    Budinger, James M.; Becker, Neal D.; Johnson, Peter N.

    1993-01-01

    Prototype decoding system operates at 200 Mb/s. ACS (add/compare/select) gate array is highly integrated emitter-coupled-logic circuit implementing arithmetic operations essential to Viterbi decoding of convolutionally encoded data signals. Principal advantage of circuit is speed. Operates as single unit performing eight additions and finds minimum of eight sums, or operates as two independent units, each performing four additions and finding minimum of four sums. Flexibility enables application to variety of different codes. Includes built-in self-testing circuitry, enabling unit to be tested at full speed with help of only simple test fixture.

  2. Diagnostic Coding for Epilepsy.

    PubMed

    Williams, Korwyn; Nuwer, Marc R; Buchhalter, Jeffrey R

    2016-02-01

    Accurate coding is an important function of neurologic practice. This contribution to Continuum is part of an ongoing series that presents helpful coding information along with examples related to the issue topic. Tips for diagnosis coding, Evaluation and Management coding, procedure coding, or a combination are presented, depending on which is most applicable to the subject area of the issue.

  3. Model Children's Code.

    ERIC Educational Resources Information Center

    New Mexico Univ., Albuquerque. American Indian Law Center.

    The Model Children's Code was developed to provide a legally correct model code that American Indian tribes can use to enact children's codes that fulfill their legal, cultural and economic needs. Code sections cover the court system, jurisdiction, juvenile offender procedures, minor-in-need-of-care, and termination. Almost every Code section is…

  4. Phylogeny of genetic codes and punctuation codes within genetic codes.

    PubMed

    Seligmann, Hervé

    2015-03-01

    Punctuation codons (starts, stops) delimit genes, reflect translation apparatus properties. Most codon reassignments involve punctuation. Here two complementary approaches classify natural genetic codes: (A) properties of amino acids assigned to codons (classical phylogeny), coding stops as X (A1, antitermination/suppressor tRNAs insert unknown residues), or as gaps (A2, no translation, classical stop); and (B) considering only punctuation status (start, stop and other codons coded as -1, 0 and 1 (B1); 0, -1 and 1 (B2, reflects ribosomal translational dynamics); and 1, -1, and 0 (B3, starts/stops as opposites)). All methods separate most mitochondrial codes from most nuclear codes; Gracilibacteria consistently cluster with metazoan mitochondria; mitochondria co-hosted with chloroplasts cluster with nuclear codes. Method A1 clusters the euplotid nuclear code with metazoan mitochondria; A2 separates euplotids from mitochondria. Firmicute bacteria Mycoplasma/Spiroplasma and Protozoan (and lower metazoan) mitochondria share codon-amino acid assignments. A1 clusters them with mitochondria, they cluster with the standard genetic code under A2: constraints on amino acid ambiguity versus punctuation-signaling produced the mitochondrial versus bacterial versions of this genetic code. Punctuation analysis B2 converges best with classical phylogenetic analyses, stressing the need for a unified theory of genetic code punctuation accounting for ribosomal constraints.

  5. Jitter compensation circuit

    DOEpatents

    Sullivan, J.S.; Ball, D.G.

    1997-09-09

    The instantaneous V{sub co} signal on a charging capacitor is sampled and the charge voltage on capacitor C{sub o} is captured just prior to its discharge into the first stage of magnetic modulator. The captured signal is applied to an averaging circuit with a long time constant and to the positive input terminal of a differential amplifier. The averaged V{sub co} signal is split between a gain stage (G = 0.975) and a feedback stage that determines the slope of the voltage ramp applied to the high speed comparator. The 97.5% portion of the averaged V{sub co} signal is applied to the negative input of a differential amplifier gain stage (G = 10). The differential amplifier produces an error signal by subtracting 97.5% of the averaged V{sub co} signal from the instantaneous value of sampled V{sub co} signal and multiplying the difference by ten. The resulting error signal is applied to the positive input of a high speed comparator. The error signal is then compared to a voltage ramp that is proportional to the averaged V{sub co} values squared divided by the total volt-second product of the magnetic compression circuit. 11 figs.

  6. Jitter compensation circuit

    DOEpatents

    Sullivan, James S.; Ball, Don G.

    1997-01-01

    The instantaneous V.sub.co signal on a charging capacitor is sampled and the charge voltage on capacitor C.sub.o is captured just prior to its discharge into the first stage of magnetic modulator. The captured signal is applied to an averaging circuit with a long time constant and to the positive input terminal of a differential amplifier. The averaged V.sub. co signal is split between a gain stage (G=0.975) and a feedback stage that determines the slope of the voltage ramp applied to the high speed comparator. The 97.5% portion of the averaged V.sub.co signal is applied to the negative input of a differential amplifier gain stage (G=10). The differential amplifier produces an error signal by subtracting 97.5% of the averaged V.sub.co signal from the instantaneous value of sampled V.sub.co signal and multiplying the difference by ten. The resulting error signal is applied to the positive input of a high speed comparator. The error signal is then compared to a voltage ramp that is proportional to the averaged V.sub.co values squared divided by the total volt-second product of the magnetic compression circuit.

  7. Simple Cell Balance Circuit

    NASA Technical Reports Server (NTRS)

    Johnson, Steven D.; Byers, Jerry W.; Martin, James A.

    2012-01-01

    A method has been developed for continuous cell voltage balancing for rechargeable batteries (e.g. lithium ion batteries). A resistor divider chain is provided that generates a set of voltages representing the ideal cell voltage (the voltage of each cell should be as if the cells were perfectly balanced). An operational amplifier circuit with an added current buffer stage generates the ideal voltage with a very high degree of accuracy, using the concept of negative feedback. The ideal voltages are each connected to the corresponding cell through a current- limiting resistance. Over time, having the cell connected to the ideal voltage provides a balancing current that moves the cell voltage very close to that ideal level. In effect, it adjusts the current of each cell during charging, discharging, and standby periods to force the cell voltages to be equal to the ideal voltages generated by the resistor divider. The device also includes solid-state switches that disconnect the circuit from the battery so that it will not discharge the battery during storage. This solution requires relatively few parts and is, therefore, of lower cost and of increased reliability due to the fewer failure modes. Additionally, this design uses very little power. A preliminary model predicts a power usage of 0.18 W for an 8-cell battery. This approach is applicable to a wide range of battery capacities and voltages.

  8. Quasi-Linear Circuit

    NASA Technical Reports Server (NTRS)

    Bradley, William; Bird, Ross; Eldred, Dennis; Zook, Jon; Knowles, Gareth

    2013-01-01

    This work involved developing spacequalifiable switch mode DC/DC power supplies that improve performance with fewer components, and result in elimination of digital components and reduction in magnetics. This design is for missions where systems may be operating under extreme conditions, especially at elevated temperature levels from 200 to 300 degC. Prior art for radiation-tolerant DC/DC converters has been accomplished utilizing classical magnetic-based switch mode converter topologies; however, this requires specific shielding and component de-rating to meet the high-reliability specifications. It requires complex measurement and feedback components, and will not enable automatic re-optimization for larger changes in voltage supply or electrical loading condition. The innovation is a switch mode DC/DC power supply that eliminates the need for processors and most magnetics. It can provide a well-regulated voltage supply with a gain of 1:100 step-up to 8:1 step down, tolerating an up to 30% fluctuation of the voltage supply parameters. The circuit incorporates a ceramic core transformer in a manner that enables it to provide a well-regulated voltage output without use of any processor components or magnetic transformers. The circuit adjusts its internal parameters to re-optimize its performance for changes in supply voltage, environmental conditions, or electrical loading at the output

  9. Automated Design of Quantum Circuits

    NASA Technical Reports Server (NTRS)

    Williams, Colin P.; Gray, Alexander G.

    2000-01-01

    In order to design a quantum circuit that performs a desired quantum computation, it is necessary to find a decomposition of the unitary matrix that represents that computation in terms of a sequence of quantum gate operations. To date, such designs have either been found by hand or by exhaustive enumeration of all possible circuit topologies. In this paper we propose an automated approach to quantum circuit design using search heuristics based on principles abstracted from evolutionary genetics, i.e. using a genetic programming algorithm adapted specially for this problem. We demonstrate the method on the task of discovering quantum circuit designs for quantum teleportation. We show that to find a given known circuit design (one which was hand-crafted by a human), the method considers roughly an order of magnitude fewer designs than naive enumeration. In addition, the method finds novel circuit designs superior to those previously known.

  10. A bit serial sequential circuit

    NASA Technical Reports Server (NTRS)

    Hu, S.; Whitaker, S.

    1990-01-01

    Normally a sequential circuit with n state variables consists of n unique hardware realizations, one for each state variable. All variables are processed in parallel. This paper introduces a new sequential circuit architecture that allows the state variables to be realized in a serial manner using only one next state logic circuit. The action of processing the state variables in a serial manner has never been addressed before. This paper presents a general design procedure for circuit construction and initialization. Utilizing pass transistors to form the combinational next state forming logic in synchronous sequential machines, a bit serial state machine can be realized with a single NMOS pass transistor network connected to shift registers. The bit serial state machine occupies less area than other realizations which perform parallel operations. Moreover, the logical circuit of the bit serial state machine can be modified by simply changing the circuit input matrix to develop an adaptive state machine.

  11. Electronic control circuits: A compilation

    NASA Technical Reports Server (NTRS)

    1973-01-01

    A compilation of technical R and D information on circuits and modular subassemblies is presented as a part of a technology utilization program. Fundamental design principles and applications are given. Electronic control circuits discussed include: anti-noise circuit; ground protection device for bioinstrumentation; temperature compensation for operational amplifiers; hybrid gatling capacitor; automatic signal range control; integrated clock-switching control; and precision voltage tolerance detector.

  12. Power-Supply-Conditioning Circuit

    NASA Technical Reports Server (NTRS)

    Primas, L. E.; Loveland, R. C.

    1989-01-01

    Fluctuations of voltage suppressed in power supplies for precise radio-frequency circuits. Circuit suppresses both periodic and random deviations of dc supply voltage from desired steady level. Highly-stable feedback voltage regulator, conditioner intended in conjunction with conventional power-supply circuit to provide constant voltage to atomic frequency standard or other precise oscillator. Without conditioners, outputs of most commercial power supplies contain fluctuations causing unacceptably-large phase and amplitude modulation of precise oscillators.

  13. Pharmacokinetics and RC Circuit Concepts

    NASA Astrophysics Data System (ADS)

    Cock, Mieke De; Janssen, Paul

    2013-11-01

    Most introductory physics courses include a chapter on RC circuits in which the differential equations for the charging and discharging of a capacitor are derived. A number of papers in this journal describe lab experiments dealing with the measurement of different parameters in such RC circuits. In this contribution, we report on a lab experiment we developed for students majoring in pharmacy, using RC circuits to simulate a pharmacokinetic process.

  14. Source-circuit design overview

    NASA Technical Reports Server (NTRS)

    Ross, R. G., Jr.

    1983-01-01

    The source circuit is the fundamental electrical building block of a large central-station array; it consists of a series-parallel network of solar cells that develops full system voltage. The array field is generally made up of a large number of parallel source circuits. Source-circuit electrical configuration is driven by a number of design considerations, which must be considered simultaneously. Array fault tolerance and hot spot heating endurance are examined in detail.

  15. Magnetic compression laser driving circuit

    DOEpatents

    Ball, Don G.; Birx, Dan; Cook, Edward G.

    1993-01-01

    A magnetic compression laser driving circuit is disclosed. The magnetic compression laser driving circuit compresses voltage pulses in the range of 1.5 microseconds at 20 Kilovolts of amplitude to pulses in the range of 40 nanoseconds and 60 Kilovolts of amplitude. The magnetic compression laser driving circuit includes a multi-stage magnetic switch where the last stage includes a switch having at least two turns which has larger saturated inductance with less core material so that the efficiency of the circuit and hence the laser is increased.

  16. Magnetic compression laser driving circuit

    DOEpatents

    Ball, D.G.; Birx, D.; Cook, E.G.

    1993-01-05

    A magnetic compression laser driving circuit is disclosed. The magnetic compression laser driving circuit compresses voltage pulses in the range of 1.5 microseconds at 20 kilovolts of amplitude to pulses in the range of 40 nanoseconds and 60 kilovolts of amplitude. The magnetic compression laser driving circuit includes a multi-stage magnetic switch where the last stage includes a switch having at least two turns which has larger saturated inductance with less core material so that the efficiency of the circuit and hence the laser is increased.

  17. Four-junction superconducting circuit

    NASA Astrophysics Data System (ADS)

    Qiu, Yueyin; Xiong, Wei; He, Xiao-Ling; Li, Tie-Fu; You, J. Q.

    2016-06-01

    We develop a theory for the quantum circuit consisting of a superconducting loop interrupted by four Josephson junctions and pierced by a magnetic flux (either static or time-dependent). In addition to the similarity with the typical three-junction flux qubit in the double-well regime, we demonstrate the difference of the four-junction circuit from its three-junction analogue, including its advantages over the latter. Moreover, the four-junction circuit in the single-well regime is also investigated. Our theory provides a tool to explore the physical properties of this four-junction superconducting circuit.

  18. PRECISION TIME-DELAY CIRCUIT

    DOEpatents

    Creveling, R.

    1959-03-17

    A tine-delay circuit which produces a delay time in d. The circuit a capacitor, an te back resistance, connected serially with the anode of the diode going to ground. At the start of the time delay a negative stepfunction is applied to the series circuit and initiates a half-cycle transient oscillatory voltage terminated by a transient oscillatory voltage of substantially higher frequency. The output of the delay circuit is taken at the junction of the inductor and diode where a sudden voltage rise appears after the initiation of the higher frequency transient oscillations.

  19. Multifunctional pattern-generating circuits.

    PubMed

    Briggman, K L; Kristan, W B

    2008-01-01

    The ability of distinct anatomical circuits to generate multiple behavioral patterns is widespread among vertebrate and invertebrate species. These multifunctional neuronal circuits are the result of multistable neural dynamics and modular organization. The evidence suggests multifunctional circuits can be classified by distinct architectures, yet the activity patterns of individual neurons involved in more than one behavior can vary dramatically. Several mechanisms, including sensory input, the parallel activity of projection neurons, neuromodulation, and biomechanics, are responsible for the switching between patterns. Recent advances in both analytical and experimental tools have aided the study of these complex circuits.

  20. A Circuit to Demonstrate Phase Relationships in "RLC" Circuits

    ERIC Educational Resources Information Center

    Sokol, P. E.; Warren, G.; Zheng, B.; Smith, P.

    2013-01-01

    We have developed a circuit to demonstrate the phase relationships between resistive and reactive elements in series "RLC" circuits. We utilize a differential amplifier to allow the phases of the three elements and the current to be simultaneously displayed on an inexpensive four channel oscilloscope. We have included a novel circuit…

  1. Circuit Theory for Full Counting Statistics in Multiterminal Circuits

    NASA Astrophysics Data System (ADS)

    Nazarov, Yu. V.; Bagrets, D. A.

    2002-05-01

    We propose a theory that treats the current, noise, and, generally, the full current statistics of electron transfer in a mesoscopic system in a unified, simple, and efficient way. The theory appears to be a circuit theory of 2×2 matrices associated with Keldysh Green functions. We illustrate the theory by considering the big fluctuations of currents in various three-terminal circuits.

  2. ELECTRONIC INTEGRATING CIRCUIT

    DOEpatents

    Englemann, R.H.

    1963-08-20

    An electronic integrating circuit using a transistor with a capacitor connected between the emitter and collector through which the capacitor discharges at a rate proportional to the input current at the base is described. Means are provided for biasing the base with an operating bias and for applying a voltage pulse to the capacitor for charging to an initial voltage. A current dividing diode is connected between the base and emitter of the transistor, and signal input terminal means are coupled to the juncture of the capacitor and emitter and to the base of the transistor. At the end of the integration period, the residual voltage on said capacitor is less by an amount proportional to the integral of the input signal. Either continuous or intermittent periods of integration are provided. (AEC)

  3. ELECTRONIC PULSE SCALING CIRCUITS

    DOEpatents

    Cooke-Yarborough, E.H.

    1958-11-18

    Electronic pulse scaling circults of the klnd comprlsing a serles of bi- stable elements connected ln sequence, usually in the form of a rlng so as to be cycllcally repetitive at the highest scallng factor, are described. The scaling circuit comprises a ring system of bi-stable elements each arranged on turn-off to cause, a succeeding element of the ring to be turned-on, and one being arranged on turn-off to cause a further element of the ring to be turned-on. In addition, separate means are provided for applying a turn-off pulse to all the elements simultaneously, and for resetting the elements to a starting condition at the end of each cycle.

  4. Modeling cortical circuits.

    SciTech Connect

    Rohrer, Brandon Robinson; Rothganger, Fredrick H.; Verzi, Stephen J.; Xavier, Patrick Gordon

    2010-09-01

    The neocortex is perhaps the highest region of the human brain, where audio and visual perception takes place along with many important cognitive functions. An important research goal is to describe the mechanisms implemented by the neocortex. There is an apparent regularity in the structure of the neocortex [Brodmann 1909, Mountcastle 1957] which may help simplify this task. The work reported here addresses the problem of how to describe the putative repeated units ('cortical circuits') in a manner that is easily understood and manipulated, with the long-term goal of developing a mathematical and algorithmic description of their function. The approach is to reduce each algorithm to an enhanced perceptron-like structure and describe its computation using difference equations. We organize this algorithmic processing into larger structures based on physiological observations, and implement key modeling concepts in software which runs on parallel computing hardware.

  5. High-threshold decoding algorithms for the gauge color code

    NASA Astrophysics Data System (ADS)

    Zeng, William; Brown, Benjamin

    Gauge color codes are topological quantum error correcting codes on three dimensional lattices. They have garnered recent interest due to two important properties: (1) they admit a universal transversal gate set, and (2) their structure allows reliable error correction using syndrome data obtained from a measurement circuit of constant depth. Both of these properties make gauge color codes intriguing candidates for low overhead fault-tolerant quantum computation. Recent work by Brown et al. calculated a threshold of 0.31% for a particular gauge color code lattice using a simple clustering decoder and phenomenological noise. We show that we can achieve improved threshold error rates using the efficient Wootton and Loss Markov-chain Monte Carlo (MCMC) decoding. In the case of the surface code, the MCMC decoder produced a threshold close to that code's upper bound. While no upper bound is known for gauge color codes, the thresholds we present here may give a better estimate.

  6. Fault-Tolerant Coding for State Machines

    NASA Technical Reports Server (NTRS)

    Naegle, Stephanie Taft; Burke, Gary; Newell, Michael

    2008-01-01

    Two reliable fault-tolerant coding schemes have been proposed for state machines that are used in field-programmable gate arrays and application-specific integrated circuits to implement sequential logic functions. The schemes apply to strings of bits in state registers, which are typically implemented in practice as assemblies of flip-flop circuits. If a single-event upset (SEU, a radiation-induced change in the bit in one flip-flop) occurs in a state register, the state machine that contains the register could go into an erroneous state or could hang, by which is meant that the machine could remain in undefined states indefinitely. The proposed fault-tolerant coding schemes are intended to prevent the state machine from going into an erroneous or hang state when an SEU occurs. To ensure reliability of the state machine, the coding scheme for bits in the state register must satisfy the following criteria: 1. All possible states are defined. 2. An SEU brings the state machine to a known state. 3. There is no possibility of a hang state. 4. No false state is entered. 5. An SEU exerts no effect on the state machine. Fault-tolerant coding schemes that have been commonly used include binary encoding and "one-hot" encoding. Binary encoding is the simplest state machine encoding and satisfies criteria 1 through 3 if all possible states are defined. Binary encoding is a binary count of the state machine number in sequence; the table represents an eight-state example. In one-hot encoding, N bits are used to represent N states: All except one of the bits in a string are 0, and the position of the 1 in the string represents the state. With proper circuit design, one-hot encoding can satisfy criteria 1 through 4. Unfortunately, the requirement to use N bits to represent N states makes one-hot coding inefficient.

  7. Digital circuits using universal logic gates

    NASA Technical Reports Server (NTRS)

    Whitaker, Sterling R. (Inventor); Miles, Lowell H. (Inventor); Cameron, Eric G. (Inventor); Donohoe, Gregory W. (Inventor); Gambles, Jody W. (Inventor)

    2004-01-01

    According to the invention, a digital circuit design embodied in at least one of a structural netlist, a behavioral netlist, a hardware description language netlist, a full-custom ASIC, a semi-custom ASIC, an IP core, an integrated circuit, a hybrid of chips, one or more masks, a FPGA, and a circuit card assembly is disclosed. The digital circuit design includes first and second sub-circuits. The first sub-circuits comprise a first percentage of the digital circuit design and the second sub-circuits comprise a second percentage of the digital circuit design. Each of the second sub-circuits is substantially comprised of one or more kernel circuits. The kernel circuits are comprised of selection circuits. The second percentage is at least 5%. In various embodiments, the second percentage could be at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 95%.

  8. Reduced circuit implementation of encoder and syndrome generator

    DOEpatents

    Trager, Barry M; Winograd, Shmuel

    2014-05-27

    An error correction method and system includes an Encoder and Syndrome-generator that operate in parallel to reduce the amount of circuitry used to compute check symbols and syndromes for error correcting codes. The system and method computes the contributions to the syndromes and check symbols 1 bit at a time instead of 1 symbol at a time. As a result, the even syndromes can be computed as powers of the odd syndromes. Further, the system assigns symbol addresses so that there are, for an example GF(2.sup.8) which has 72 symbols, three (3) blocks of addresses which differ by a cube root of unity to allow the data symbols to be combined for reducing size and complexity of odd syndrome circuits. Further, the implementation circuit for generating check symbols is derived from syndrome circuit using the inverse of the part of the syndrome matrix for check locations.

  9. Accumulate repeat accumulate codes

    NASA Technical Reports Server (NTRS)

    Abbasfar, Aliazam; Divsalar, Dariush; Yao, Kung

    2004-01-01

    In this paper we propose an innovative channel coding scheme called 'Accumulate Repeat Accumulate codes' (ARA). This class of codes can be viewed as serial turbo-like codes, or as a subclass of Low Density Parity Check (LDPC) codes, thus belief propagation can be used for iterative decoding of ARA codes on a graph. The structure of encoder for this class can be viewed as precoded Repeat Accumulate (RA) code or as precoded Irregular Repeat Accumulate (IRA) code, where simply an accumulator is chosen as a precoder. Thus ARA codes have simple, and very fast encoder structure when they representing LDPC codes. Based on density evolution for LDPC codes through some examples for ARA codes, we show that for maximum variable node degree 5 a minimum bit SNR as low as 0.08 dB from channel capacity for rate 1/2 can be achieved as the block size goes to infinity. Thus based on fixed low maximum variable node degree, its threshold outperforms not only the RA and IRA codes but also the best known LDPC codes with the dame maximum node degree. Furthermore by puncturing the accumulators any desired high rate codes close to code rate 1 can be obtained with thresholds that stay close to the channel capacity thresholds uniformly. Iterative decoding simulation results are provided. The ARA codes also have projected graph or protograph representation that allows for high speed decoder implementation.

  10. Pharmacokinetics and "RC" Circuit Concepts

    ERIC Educational Resources Information Center

    De Cock, Mieke; Janssen, Paul

    2013-01-01

    Most introductory physics courses include a chapter on "RC" circuits in which the differential equations for the charging and discharging of a capacitor are derived. A number of papers in this journal describe lab experiments dealing with the measurement of different parameters in such "RC" circuits. In this contribution, we…

  11. Cell short circuit, preshort signature

    NASA Technical Reports Server (NTRS)

    Lurie, C.

    1980-01-01

    Short-circuit events observed in ground test simulations of DSCS-3 battery in-orbit operations are analyzed. Voltage signatures appearing in the data preceding the short-circuit event are evaluated. The ground test simulation is briefly described along with performance during reconditioning discharges. Results suggest that a characteristic signature develops prior to a shorting event.

  12. Sequential Polarity-Reversing Circuit

    NASA Technical Reports Server (NTRS)

    Labaw, Clayton C.

    1994-01-01

    Proposed circuit reverses polarity of electric power supplied to bidirectional dc motor, reversible electro-mechanical actuator, or other device operating in direction depending on polarity. Circuit reverses polarity each time power turned on, without need for additional polarity-reversing or direction signals and circuitry to process them.

  13. Demonstrations with an "LCR" Circuit

    ERIC Educational Resources Information Center

    Kraftmakher, Yaakov

    2011-01-01

    The "LCR" circuit is an important topic in the course of electricity and magnetism. Papers in this field consider mainly the forced oscillations and resonance. Our aim is to show how to demonstrate the free and self-excited oscillations in an "LCR" circuit. (Contains 4 figures.)

  14. Time domain analog circuit simulation

    NASA Astrophysics Data System (ADS)

    Fijnvandraat, J. G.; Houben, S. H. M. J.; Ter Maten, E. J. W.; Peters, J. M. F.

    2006-01-01

    Recent developments of new methods for simulating electric circuits are described. Emphasis is put on methods that fit existing datastructures for backward differentiation formulae methods. These methods can be modified to apply to hierarchically organized datastructures, which allows for efficient simulation of large designs of circuits in the electronics industry.

  15. Trigger Circuit for Marx Generators

    DTIC Science & Technology

    2001-02-08

    A trigger circuit is provided for a trigger system for a Marx generator column. The column includes a plurality of metal electrode pairs wherein the...electrode (trigatron) spark gap switch forming the first spark gap of the Marx generator column. The triggering circuit includes a trigger

  16. Dive In to Aquatic Circuits.

    ERIC Educational Resources Information Center

    Goldfarb, Joseph M.

    1995-01-01

    The article presents a method for swimming teachers and coaches to stave off workout boredom in their students by using a circuit in the pool. After explaining how to set up a training circuit, the article describes sample stations and notes important safety precautions. (SM)

  17. Concatenated Coding Using Trellis-Coded Modulation

    NASA Technical Reports Server (NTRS)

    Thompson, Michael W.

    1997-01-01

    In the late seventies and early eighties a technique known as Trellis Coded Modulation (TCM) was developed for providing spectrally efficient error correction coding. Instead of adding redundant information in the form of parity bits, redundancy is added at the modulation stage thereby increasing bandwidth efficiency. A digital communications system can be designed to use bandwidth-efficient multilevel/phase modulation such as Amplitude Shift Keying (ASK), Phase Shift Keying (PSK), Differential Phase Shift Keying (DPSK) or Quadrature Amplitude Modulation (QAM). Performance gain can be achieved by increasing the number of signals over the corresponding uncoded system to compensate for the redundancy introduced by the code. A considerable amount of research and development has been devoted toward developing good TCM codes for severely bandlimited applications. More recently, the use of TCM for satellite and deep space communications applications has received increased attention. This report describes the general approach of using a concatenated coding scheme that features TCM and RS coding. Results have indicated that substantial (6-10 dB) performance gains can be achieved with this approach with comparatively little bandwidth expansion. Since all of the bandwidth expansion is due to the RS code we see that TCM based concatenated coding results in roughly 10-50% bandwidth expansion compared to 70-150% expansion for similar concatenated scheme which use convolution code. We stress that combined coding and modulation optimization is important for achieving performance gains while maintaining spectral efficiency.

  18. Coset Codes Viewed as Terminated Convolutional Codes

    NASA Technical Reports Server (NTRS)

    Fossorier, Marc P. C.; Lin, Shu

    1996-01-01

    In this paper, coset codes are considered as terminated convolutional codes. Based on this approach, three new general results are presented. First, it is shown that the iterative squaring construction can equivalently be defined from a convolutional code whose trellis terminates. This convolutional code determines a simple encoder for the coset code considered, and the state and branch labelings of the associated trellis diagram become straightforward. Also, from the generator matrix of the code in its convolutional code form, much information about the trade-off between the state connectivity and complexity at each section, and the parallel structure of the trellis, is directly available. Based on this generator matrix, it is shown that the parallel branches in the trellis diagram of the convolutional code represent the same coset code C(sub 1), of smaller dimension and shorter length. Utilizing this fact, a two-stage optimum trellis decoding method is devised. The first stage decodes C(sub 1), while the second stage decodes the associated convolutional code, using the branch metrics delivered by stage 1. Finally, a bidirectional decoding of each received block starting at both ends is presented. If about the same number of computations is required, this approach remains very attractive from a practical point of view as it roughly doubles the decoding speed. This fact is particularly interesting whenever the second half of the trellis is the mirror image of the first half, since the same decoder can be implemented for both parts.

  19. An Electronics Course Emphasizing Circuit Design

    ERIC Educational Resources Information Center

    Bergeson, Haven E.

    1975-01-01

    Describes a one-quarter introductory electronics course in which the students use a variety of inexpensive integrated circuits to design and construct a large number of useful circuits. Presents the subject matter of the course in three parts: linear circuits, digital circuits, and more complex circuits. (GS)

  20. 49 CFR 236.728 - Circuit, trap.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Circuit, trap. 236.728 Section 236.728... Circuit, trap. A term applied to a circuit used where it is desirable to provide a track circuit but where it is impracticable to maintain a track circuit....

  1. Demultiplexer circuit for neural stimulation

    DOEpatents

    Wessendorf, Kurt O; Okandan, Murat; Pearson, Sean

    2012-10-09

    A demultiplexer circuit is disclosed which can be used with a conventional neural stimulator to extend the number of electrodes which can be activated. The demultiplexer circuit, which is formed on a semiconductor substrate containing a power supply that provides all the dc electrical power for operation of the circuit, includes digital latches that receive and store addressing information from the neural stimulator one bit at a time. This addressing information is used to program one or more 1:2.sup.N demultiplexers in the demultiplexer circuit which then route neural stimulation signals from the neural stimulator to an electrode array which is connected to the outputs of the 1:2.sup.N demultiplexer. The demultiplexer circuit allows the number of individual electrodes in the electrode array to be increased by a factor of 2.sup.N with N generally being in a range of 2-4.

  2. Genetic Dissection of Neural Circuits

    PubMed Central

    Luo, Liqun; Callaway, Edward M.; Svoboda, Karel

    2009-01-01

    Understanding the principles of information processing in neural circuits requires systematic characterization of the participating cell types and their connections, and the ability to measure and perturb their activity. Genetic approaches promise to bring experimental access to complex neural systems, including genetic stalwarts such as the fly and mouse, but also to nongenetic systems such as primates. Together with anatomical and physiological methods, cell-type-specific expression of protein markers and sensors and transducers will be critical to construct circuit diagrams and to measure the activity of genetically defined neurons. Inactivation and activation of genetically defined cell types will establish causal relationships between activity in specific groups of neurons, circuit function, and animal behavior. Genetic analysis thus promises to reveal the logic of the neural circuits in complex brains that guide behaviors. Here we review progress in the genetic analysis of neural circuits and discuss directions for future research and development. PMID:18341986

  3. Photodiode circuits for retinal prostheses.

    PubMed

    Loudin, J D; Cogan, S F; Mathieson, K; Sher, A; Palanker, D V

    2011-10-01

    Photodiode circuits show promise for the development of high-resolution retinal prostheses. While several of these systems have been constructed and some even implanted in humans, existing descriptions of the complex optoelectronic interaction between light, photodiode, and the electrode/electrolyte load are limited. This study examines this interaction in depth with theoretical calculations and experimental measurements. Actively biased photoconductive and passive photovoltaic circuits are investigated, with the photovoltaic circuits consisting of one or more diodes connected in series, and the photoconductive circuits consisting of a single diode in series with a pulsed bias voltage. Circuit behavior and charge injection levels were markedly different for platinum and sputtered iridium-oxide film (SIROF) electrodes. Photovoltaic circuits were able to deliver 0.038 mC/cm(2) (0.75 nC/phase) per photodiode with 50- μm platinum electrodes, and 0.54-mC/cm(2) (11 nC/phase) per photodiode with 50-μ m SIROF electrodes driven with 0.5-ms pulses of light at 25 Hz. The same pulses applied to photoconductive circuits with the same electrodes were able to deliver charge injections as high as 0.38 and 7.6 mC/cm(2) (7.5 and 150 nC/phase), respectively. We demonstrate photovoltaic stimulation of rabbit retina in-vitro, with 0.5-ms pulses of 905-nm light using peak irradiance of 1 mW/mm(2). Based on the experimental data, we derive electrochemical and optical safety limits for pixel density and charge injection in various circuits. While photoconductive circuits offer smaller pixels, photovoltaic systems do not require an external bias voltage. Both classes of circuits show promise for the development of high-resolution optoelectronic retinal prostheses.

  4. Gate drive latching circuit for an auxiliary resonant commutation circuit

    NASA Technical Reports Server (NTRS)

    Delgado, Eladio Clemente (Inventor); Kheraluwala, Mustansir Hussainy (Inventor)

    1999-01-01

    A gate drive latching circuit for an auxiliary resonant commutation circuit for a power switching inverter includes a current monitor circuit providing a current signal to a pair of analog comparators to implement latching of one of a pair of auxiliary switching devices which are used to provide commutation current for commutating switching inverters in the circuit. Each of the pair of comparators feeds a latching circuit which responds to an active one of the comparators for latching the associated gate drive circuit for one of the pair of auxiliary commutating switches. An initial firing signal is applied to each of the commutating switches to gate each into conduction and the resulting current is monitored to determine current direction and therefore the one of the switches which is carrying current. The comparator provides a latching signal to the one of the auxiliary power switches which is actually conducting current and latches that particular power switch into an on state for the duration of current through the device. The latching circuit is so designed that the only time one of the auxiliary switching devices can be latched on is during the duration of an initial firing command signal.

  5. Discussion on LDPC Codes and Uplink Coding

    NASA Technical Reports Server (NTRS)

    Andrews, Ken; Divsalar, Dariush; Dolinar, Sam; Moision, Bruce; Hamkins, Jon; Pollara, Fabrizio

    2007-01-01

    This slide presentation reviews the progress that the workgroup on Low-Density Parity-Check (LDPC) for space link coding. The workgroup is tasked with developing and recommending new error correcting codes for near-Earth, Lunar, and deep space applications. Included in the presentation is a summary of the technical progress of the workgroup. Charts that show the LDPC decoder sensitivity to symbol scaling errors are reviewed, as well as a chart showing the performance of several frame synchronizer algorithms compared to that of some good codes and LDPC decoder tests at ESTL. Also reviewed is a study on Coding, Modulation, and Link Protocol (CMLP), and the recommended codes. A design for the Pseudo-Randomizer with LDPC Decoder and CRC is also reviewed. A chart that summarizes the three proposed coding systems is also presented.

  6. Bar Codes for Libraries.

    ERIC Educational Resources Information Center

    Rahn, Erwin

    1984-01-01

    Discusses the evolution of standards for bar codes (series of printed lines and spaces that represent numbers, symbols, and/or letters of alphabet) and describes the two types most frequently adopted by libraries--Code-A-Bar and CODE 39. Format of the codes is illustrated. Six references and definitions of terminology are appended. (EJS)

  7. Manually operated coded switch

    DOEpatents

    Barnette, Jon H.

    1978-01-01

    The disclosure relates to a manually operated recodable coded switch in which a code may be inserted, tried and used to actuate a lever controlling an external device. After attempting a code, the switch's code wheels must be returned to their zero positions before another try is made.

  8. QR Codes 101

    ERIC Educational Resources Information Center

    Crompton, Helen; LaFrance, Jason; van 't Hooft, Mark

    2012-01-01

    A QR (quick-response) code is a two-dimensional scannable code, similar in function to a traditional bar code that one might find on a product at the supermarket. The main difference between the two is that, while a traditional bar code can hold a maximum of only 20 digits, a QR code can hold up to 7,089 characters, so it can contain much more…

  9. ARA type protograph codes

    NASA Technical Reports Server (NTRS)

    Divsalar, Dariush (Inventor); Abbasfar, Aliazam (Inventor); Jones, Christopher R. (Inventor); Dolinar, Samuel J. (Inventor); Thorpe, Jeremy C. (Inventor); Andrews, Kenneth S. (Inventor); Yao, Kung (Inventor)

    2008-01-01

    An apparatus and method for encoding low-density parity check codes. Together with a repeater, an interleaver and an accumulator, the apparatus comprises a precoder, thus forming accumulate-repeat-accumulate (ARA codes). Protographs representing various types of ARA codes, including AR3A, AR4A and ARJA codes, are described. High performance is obtained when compared to the performance of current repeat-accumulate (RA) or irregular-repeat-accumulate (IRA) codes.

  10. 30 CFR 75.800 - High-voltage circuits; circuit breakers.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false High-voltage circuits; circuit breakers. 75.800... § 75.800 High-voltage circuits; circuit breakers. High-voltage circuits entering the underground area of any coal mine shall be protected by suitable circuit breakers of adequate interrupting...

  11. 49 CFR 236.731 - Controller, circuit.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Controller, circuit. A device for opening and closing electric circuits. ... 49 Transportation 4 2013-10-01 2013-10-01 false Controller, circuit. 236.731 Section 236.731 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD...

  12. 49 CFR 236.731 - Controller, circuit.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Controller, circuit. A device for opening and closing electric circuits. ... 49 Transportation 4 2012-10-01 2012-10-01 false Controller, circuit. 236.731 Section 236.731 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD...

  13. 49 CFR 236.731 - Controller, circuit.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Controller, circuit. A device for opening and closing electric circuits. ... 49 Transportation 4 2014-10-01 2014-10-01 false Controller, circuit. 236.731 Section 236.731 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD...

  14. 49 CFR 236.731 - Controller, circuit.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Controller, circuit. A device for opening and closing electric circuits. ... 49 Transportation 4 2011-10-01 2011-10-01 false Controller, circuit. 236.731 Section 236.731 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD...

  15. 49 CFR 236.731 - Controller, circuit.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Controller, circuit. A device for opening and closing electric circuits. ... 49 Transportation 4 2010-10-01 2010-10-01 false Controller, circuit. 236.731 Section 236.731 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD...

  16. Nanofluidic Transistor Circuits

    NASA Astrophysics Data System (ADS)

    Chang, Hsueh-Chia; Cheng, Li-Jing; Yan, Yu; Slouka, Zdenek; Senapati, Satyajyoti

    2012-02-01

    Non-equilibrium ion/fluid transport physics across on-chip membranes/nanopores is used to construct rectifying, hysteretic, oscillatory, excitatory and inhibitory nanofluidic elements. Analogs to linear resistors, capacitors, inductors and constant-phase elements were reported earlier (Chang and Yossifon, BMF 2009). Nonlinear rectifier is designed by introducing intra-membrane conductivity gradient and by asymmetric external depletion with a reverse rectification (Yossifon and Chang, PRL, PRE, Europhys Lett 2009-2011). Gating phenomenon is introduced by functionalizing polyelectrolytes whose conformation is field/pH sensitive (Wang, Chang and Zhu, Macromolecules 2010). Surface ion depletion can drive Rubinstein's microvortex instability (Chang, Yossifon and Demekhin, Annual Rev of Fluid Mech, 2012) or Onsager-Wien's water dissociation phenomenon, leading to two distinct overlimiting I-V features. Bipolar membranes exhibit an S-hysteresis due to water dissociation (Cheng and Chang, BMF 2011). Coupling the hysteretic diode with some linear elements result in autonomous ion current oscillations, which undergo classical transitions to chaos. Our integrated nanofluidic circuits are used for molecular sensing, protein separation/concentration, electrospray etc.

  17. PHOTOSENSITIVE RELAY CONTROL CIRCUIT

    DOEpatents

    Martin, C.F.

    1958-01-14

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

  18. Variational integrators for electric circuits

    SciTech Connect

    Ober-Blöbaum, Sina; Tao, Molei; Cheng, Mulin; Owhadi, Houman; Marsden, Jerrold E.

    2013-06-01

    In this contribution, we develop a variational integrator for the simulation of (stochastic and multiscale) electric circuits. When considering the dynamics of an electric circuit, one is faced with three special situations: 1. The system involves external (control) forcing through external (controlled) voltage sources and resistors. 2. The system is constrained via the Kirchhoff current (KCL) and voltage laws (KVL). 3. The Lagrangian is degenerate. Based on a geometric setting, an appropriate variational formulation is presented to model the circuit from which the equations of motion are derived. A time-discrete variational formulation provides an iteration scheme for the simulation of the electric circuit. Dependent on the discretization, the intrinsic degeneracy of the system can be canceled for the discrete variational scheme. In this way, a variational integrator is constructed that gains several advantages compared to standard integration tools for circuits; in particular, a comparison to BDF methods (which are usually the method of choice for the simulation of electric circuits) shows that even for simple LCR circuits, a better energy behavior and frequency spectrum preservation can be observed using the developed variational integrator.

  19. Global optimization of digital circuits

    NASA Astrophysics Data System (ADS)

    Flandera, Richard

    1991-12-01

    This thesis was divided into two tasks. The first task involved developing a parser which could translate a behavioral specification in Very High-Speed Integrated Circuits (VHSIC) Hardware Description Language (VHDL) into the format used by an existing digital circuit optimization tool, Boolean Reasoning In Scheme (BORIS). Since this tool is written in Scheme, a dialect of Lisp, the parser was also written in Scheme. The parser was implemented is Artez's modification of Earley's Algorithm. Additionally, a VHDL tokenizer was implemented in Scheme and a portion of the VHDL grammar was converted into the format which the parser uses. The second task was the incorporation of intermediate functions into BORIS. The existing BORIS contains a recursive optimization system that optimizes digital circuits by using circuit outputs as inputs into other circuits. Intermediate functions provide a greater selection of functions to be used as circuits inputs. Using both intermediate functions and output functions, the costs of the circuits in the test set were reduced by 43 percent. This is a 10 percent reduction when compared to the existing recursive optimization system. Incorporating intermediate functions into BORIS required the development of an intermediate-function generator and a set of control methods to keep the computation time from increasing exponentially.

  20. Integrated circuits, and design and manufacture thereof

    DOEpatents

    Auracher, Stefan; Pribbernow, Claus; Hils, Andreas

    2006-04-18

    A representation of a macro for an integrated circuit layout. The representation may define sub-circuit cells of a module. The module may have a predefined functionality. The sub-circuit cells may include at least one reusable circuit cell. The reusable circuit cell may be configured such that when the predefined functionality of the module is not used, the reusable circuit cell is available for re-use.

  1. Framed 4-graphs: Euler tours, Gauss circuits and rotating circuits

    SciTech Connect

    Il'yutko, Denis P

    2011-09-30

    We consider connected finite 4-valent graphs with the structure of opposite edges at each vertex (framed 4-graphs). For any of such graphs there exist Euler tours, in travelling along which at each vertex we turn from an edge to a nonopposite one (rotating circuits); and at the same time, it is not true that for any such graph there exists an Euler tour passing from an edge to the opposite one at each vertex (a Gauss circuit). The main result of the work is an explicit formula connecting the adjacency matrices of the Gauss circuit and an arbitrary Euler tour. This formula immediately gives us a criterion for the existence of a Gauss circuit on a given framed 4-graph. It turns out that the results are also valid for all symmetric matrices (not just for matrices realisable by a chord diagram). Bibliography: 24 titles.

  2. Overpulse railgun energy recovery circuit

    DOEpatents

    Honig, E.M.

    1984-09-28

    The invention presented relates to a high-power pulsing circuit and more particularly to a repetitive pulse inductive energy storage and transfer circuit for an electromagnetic launcher. In an electromagnetic launcher such as a railgun for propelling a projectile at high velocity, an overpulse energy recovery circuit is employed to transfer stored inductive energy from a source inductor to the railgun inductance to propel the projectile down the railgun. Switching circuitry and an energy transfer capacitor are used to switch the energy back to the source inductor in readiness for a repetitive projectile propelling cycle.

  3. Counterpulse railgun energy recovery circuit

    DOEpatents

    Honig, E.M.

    1984-09-28

    The invention presented relates to a high-power pulsing circuit and more particularly to a repetitive pulse inductive energy storage and transfer circuit for an electromagnetic launcher. In an electromagnetic launcher such as a railgun for propelling a projectile at high velocity, a counterpulse energy recovery circuit is employed to transfer stored inductive energy from a source inductor to the railgun inductance to propel the projectile down the railgun. Switching circuitry and an energy transfer capacitor are used to switch the energy back to the source inductor in readiness for a repetitive projectile propelling cycle.

  4. Analog circuits for relaxation networks.

    PubMed

    Card, H

    1993-12-01

    Selected examples are presented of recent advances, primarily from the U.S. and Canada, in analog circuits for relaxation networks. Relaxation networks having feedback connections exhibit potentially greater computational power per neuron than feedforward networks. They are also more poorly understood especially with respect to learning algorithms. Examples are described of analog circuits for (i) supervised learning in deterministic Boltzmann machines, (ii) unsupervised competitive learning and feature maps and (iii) networks with resistive grids for vision and audition tasks. We also discuss recent progress on in-circuit learning and synaptic weight storage mechanisms.

  5. Efficient entropy coding for scalable video coding

    NASA Astrophysics Data System (ADS)

    Choi, Woong Il; Yang, Jungyoup; Jeon, Byeungwoo

    2005-10-01

    The standardization for the scalable extension of H.264 has called for additional functionality based on H.264 standard to support the combined spatio-temporal and SNR scalability. For the entropy coding of H.264 scalable extension, Context-based Adaptive Binary Arithmetic Coding (CABAC) scheme is considered so far. In this paper, we present a new context modeling scheme by using inter layer correlation between the syntax elements. As a result, it improves coding efficiency of entropy coding in H.264 scalable extension. In simulation results of applying the proposed scheme to encoding the syntax element mb_type, it is shown that improvement in coding efficiency of the proposed method is up to 16% in terms of bit saving due to estimation of more adequate probability model.

  6. A memristive spiking neuron with firing rate coding

    PubMed Central

    Ignatov, Marina; Ziegler, Martin; Hansen, Mirko; Petraru, Adrian; Kohlstedt, Hermann

    2015-01-01

    Perception, decisions, and sensations are all encoded into trains of action potentials in the brain. The relation between stimulus strength and all-or-nothing spiking of neurons is widely believed to be the basis of this coding. This initiated the development of spiking neuron models; one of today's most powerful conceptual tool for the analysis and emulation of neural dynamics. The success of electronic circuit models and their physical realization within silicon field-effect transistor circuits lead to elegant technical approaches. Recently, the spectrum of electronic devices for neural computing has been extended by memristive devices, mainly used to emulate static synaptic functionality. Their capabilities for emulations of neural activity were recently demonstrated using a memristive neuristor circuit, while a memristive neuron circuit has so far been elusive. Here, a spiking neuron model is experimentally realized in a compact circuit comprising memristive and memcapacitive devices based on the strongly correlated electron material vanadium dioxide (VO2) and on the chemical electromigration cell Ag/TiO2−x/Al. The circuit can emulate dynamical spiking patterns in response to an external stimulus including adaptation, which is at the heart of firing rate coding as first observed by E.D. Adrian in 1926. PMID:26539074

  7. Student Conceptions of Simple Circuits.

    ERIC Educational Resources Information Center

    Fredette, Norman; Lochhead, John

    1980-01-01

    Investigates some conceptual difficulties which college students have with regard to simple direct current circuits. The clinical interview technique was used with 57 students in a freshman level engineering course. (HM)

  8. Midbrain circuits for defensive behaviour.

    PubMed

    Tovote, Philip; Esposito, Maria Soledad; Botta, Paolo; Chaudun, Fabrice; Fadok, Jonathan P; Markovic, Milica; Wolff, Steffen B E; Ramakrishnan, Charu; Fenno, Lief; Deisseroth, Karl; Herry, Cyril; Arber, Silvia; Lüthi, Andreas

    2016-06-09

    Survival in threatening situations depends on the selection and rapid execution of an appropriate active or passive defensive response, yet the underlying brain circuitry is not understood. Here we use circuit-based optogenetic, in vivo and in vitro electrophysiological, and neuroanatomical tracing methods to define midbrain periaqueductal grey circuits for specific defensive behaviours. We identify an inhibitory pathway from the central nucleus of the amygdala to the ventrolateral periaqueductal grey that produces freezing by disinhibition of ventrolateral periaqueductal grey excitatory outputs to pre-motor targets in the magnocellular nucleus of the medulla. In addition, we provide evidence for anatomical and functional interaction of this freezing pathway with long-range and local circuits mediating flight. Our data define the neuronal circuitry underlying the execution of freezing, an evolutionarily conserved defensive behaviour, which is expressed by many species including fish, rodents and primates. In humans, dysregulation of this 'survival circuit' has been implicated in anxiety-related disorders.

  9. Accelerated hybrid-circuit production

    NASA Technical Reports Server (NTRS)

    Berg, J. E.; Dassele, M. A.

    1979-01-01

    Modified die-bonding machine speeds up hybrid-circuit production. Utilizing two pedestals, one for die tray and another for substrate tray, increased production and decreased error-margin are possible.

  10. Focal plane infrared readout circuit

    NASA Technical Reports Server (NTRS)

    Pain, Bedabrata (Inventor)

    2002-01-01

    An infrared imager, such as a spectrometer, includes multiple infrared photodetectors and readout circuits for reading out signals from the photodetectors. Each readout circuit includes a buffered direct injection input circuit including a differential amplifier with active feedback provided through an injection transistor. The differential amplifier includes a pair of input transistors, a pair of cascode transistors and a current mirror load. Photocurrent from a photodetector can be injected onto an integration capacitor in the readout circuit with high injection efficiency at high speed. A high speed, low noise, wide dynamic range linear infrared multiplexer array for reading out infrared detectors with large capacitances can be achieved even when short exposure times are used. The effect of image lag can be reduced.

  11. Chaos Control for Chua's Circuits

    NASA Astrophysics Data System (ADS)

    Tôrres, L. A. B.; Aguirre, L. A.; Palhares, R. M.; Mendes, E. M. A. M.

    The practical implementation of Chua's circuit control methods is discussed in this chapter. In order to better address this subject, an inductorless Chua's circuit realization is first presented, followed by practical issues related to data analysis, mathematical modelling, and dynamical characterization associated to this electronic chaotic oscillator. As a consequence of the investigation of different control strategies applied to Chua's circuit, a tradeoff among control objective, control energy, and model complexity is devised, which quite naturally leads to a principle that seems to be of general nature: the Information Transmission Via Control (ITVC) for nonlinear oscillators. The main purpose of the present chapter is to serve as an introductory guide to the universe of Chua's circuit control, synchronization, and mathematical modelling.

  12. Reverse engineering of integrated circuits

    DOEpatents

    Chisholm, Gregory H.; Eckmann, Steven T.; Lain, Christopher M.; Veroff, Robert L.

    2003-01-01

    Software and a method therein to analyze circuits. The software comprises several tools, each of which perform particular functions in the Reverse Engineering process. The analyst, through a standard interface, directs each tool to the portion of the task to which it is most well suited, rendering previously intractable problems solvable. The tools are generally used iteratively to produce a successively more abstract picture of a circuit, about which incomplete a priori knowledge exists.

  13. Equivalent circuit for birdcage resonators.

    PubMed

    Harpen, M D

    1993-02-01

    We present an equivalent circuit analysis for both low pass and high pass birdcage resonators loaded with lossy samples. In a generalization of the method of Hoult and Lauterbur (J. Magn. Reson. 34, 425 (1979)), we also derive circuit component values by application of the laws of electrodynamics. Measured resonance spectra, quality factors, and feed point impedances in a test resonator are shown to be in agreement with those predicted by the proposed model.

  14. Honesty and Honor Codes.

    ERIC Educational Resources Information Center

    McCabe, Donald; Trevino, Linda Klebe

    2002-01-01

    Explores the rise in student cheating and evidence that students cheat less often at schools with an honor code. Discusses effective use of such codes and creation of a peer culture that condemns dishonesty. (EV)

  15. Cellulases and coding sequences

    DOEpatents

    Li, Xin-Liang; Ljungdahl, Lars G.; Chen, Huizhong

    2001-02-20

    The present invention provides three fungal cellulases, their coding sequences, recombinant DNA molecules comprising the cellulase coding sequences, recombinant host cells and methods for producing same. The present cellulases are from Orpinomyces PC-2.

  16. Cellulases and coding sequences

    DOEpatents

    Li, Xin-Liang; Ljungdahl, Lars G.; Chen, Huizhong

    2001-01-01

    The present invention provides three fungal cellulases, their coding sequences, recombinant DNA molecules comprising the cellulase coding sequences, recombinant host cells and methods for producing same. The present cellulases are from Orpinomyces PC-2.

  17. QR Code Mania!

    ERIC Educational Resources Information Center

    Shumack, Kellie A.; Reilly, Erin; Chamberlain, Nik

    2013-01-01

    space, has error-correction capacity, and can be read from any direction. These codes are used in manufacturing, shipping, and marketing, as well as in education. QR codes can be created to produce…

  18. DIANE multiparticle transport code

    NASA Astrophysics Data System (ADS)

    Caillaud, M.; Lemaire, S.; Ménard, S.; Rathouit, P.; Ribes, J. C.; Riz, D.

    2014-06-01

    DIANE is the general Monte Carlo code developed at CEA-DAM. DIANE is a 3D multiparticle multigroup code. DIANE includes automated biasing techniques and is optimized for massive parallel calculations.

  19. Full circuit calculation for electromagnetic pulse transmission in a high current facility

    NASA Astrophysics Data System (ADS)

    Zou, Wenkang; Guo, Fan; Chen, Lin; Song, Shengyi; Wang, Meng; Xie, Weiping; Deng, Jianjun

    2014-11-01

    We describe herein for the first time a full circuit model for electromagnetic pulse transmission in the Primary Test Stand (PTS)—the first TW class pulsed power driver in China. The PTS is designed to generate 8-10 MA current into a z -pinch load in nearly 90 ns rise time for inertial confinement fusion and other high energy density physics research. The PTS facility has four conical magnetic insulation transmission lines, in which electron current loss exists during the establishment of magnetic insulation. At the same time, equivalent resistance of switches and equivalent inductance of pinch changes with time. However, none of these models are included in a commercially developed circuit code so far. Therefore, in order to characterize the electromagnetic transmission process in the PTS, a full circuit model, in which switch resistance, magnetic insulation transmission line current loss and a time-dependent load can be taken into account, was developed. Circuit topology and an equivalent circuit model of the facility were introduced. Pulse transmission calculation of shot 0057 was demonstrated with the corresponding code FAST (full-circuit analysis and simulation tool) by setting controllable parameters the same as in the experiment. Preliminary full circuit simulation results for electromagnetic pulse transmission to the load are presented. Although divergences exist between calculated and experimentally obtained waveforms before the vacuum section, consistency with load current is satisfactory, especially at the rising edge.

  20. EMF wire code research

    SciTech Connect

    Jones, T.

    1993-11-01

    This paper examines the results of previous wire code research to determines the relationship with childhood cancer, wire codes and electromagnetic fields. The paper suggests that, in the original Savitz study, biases toward producing a false positive association between high wire codes and childhood cancer were created by the selection procedure.

  1. Universal Noiseless Coding Subroutines

    NASA Technical Reports Server (NTRS)

    Schlutsmeyer, A. P.; Rice, R. F.

    1986-01-01

    Software package consists of FORTRAN subroutines that perform universal noiseless coding and decoding of integer and binary data strings. Purpose of this type of coding to achieve data compression in sense that coded data represents original data perfectly (noiselessly) while taking fewer bits to do so. Routines universal because they apply to virtually any "real-world" data source.

  2. Mapping Local Codes to Read Codes.

    PubMed

    Bonney, Wilfred; Galloway, James; Hall, Christopher; Ghattas, Mikhail; Tramma, Leandro; Nind, Thomas; Donnelly, Louise; Jefferson, Emily; Doney, Alexander

    2017-01-01

    Background & Objectives: Legacy laboratory test codes make it difficult to use clinical datasets for meaningful translational research, where populations are followed for disease risk and outcomes over many years. The Health Informatics Centre (HIC) at the University of Dundee hosts continuous biochemistry data from the clinical laboratories in Tayside and Fife dating back as far as 1987. However, the HIC-managed biochemistry dataset is coupled with incoherent sample types and unstandardised legacy local test codes, which increases the complexity of using the dataset for reasonable population health outcomes. The objective of this study was to map the legacy local test codes to the Scottish 5-byte Version 2 Read Codes using biochemistry data extracted from the repository of the Scottish Care Information (SCI) Store.

  3. Difference-Equation/Flow-Graph Circuit Analysis

    NASA Technical Reports Server (NTRS)

    Mcvey, I. M.

    1988-01-01

    Numerical technique enables rapid, approximate analyses of electronic circuits containing linear and nonlinear elements. Practiced in variety of computer languages on large and small computers; for circuits simple enough, programmable hand calculators used. Although some combinations of circuit elements make numerical solutions diverge, enables quick identification of divergence and correction of circuit models to make solutions converge.

  4. Improved self arbitrated VLSI asynchronous circuits

    NASA Technical Reports Server (NTRS)

    Winterrowd, P.

    1991-01-01

    This paper introduces an improved method for designing the class of CMOS VLSI asynchronous sequential circuits introduced in the paper by Sterling R. Whitaker and Gary K. Maki, 'Self Arbitrated VLSI Asynchronous Circuits.' Of main interest here is the simple design by inspection rules that arise from these circuits. This paper presents a variation on these circuits which reduces the number of transistors required.

  5. 30 CFR 56.6403 - Branch circuits.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Branch circuits. 56.6403 Section 56.6403... Blasting § 56.6403 Branch circuits. (a) If electric blasting includes the use of branch circuits, each branch shall be equipped with a safety switch or equivalent method to isolate the circuits to be used....

  6. Multi-Layer E-Textile Circuits

    NASA Technical Reports Server (NTRS)

    Dunne, Lucy E.; Bibeau, Kaila; Mulligan, Lucie; Frith, Ashton; Simon, Cory

    2012-01-01

    Stitched e-textile circuits facilitate wearable, flexible, comfortable wearable technology. However, while stitched methods of e-textile circuits are common, multi-layer circuit creation remains a challenge. Here, we present methods of stitched multi-layer circuit creation using accessible tools and techniques.

  7. A construction of quantum turbo product codes based on CSS-type quantum convolutional codes

    NASA Astrophysics Data System (ADS)

    Xiao, Hailin; Ni, Ju; Xie, Wu; Ouyang, Shan

    As in classical coding theory, turbo product codes (TPCs) through serially concatenated block codes can achieve approximatively Shannon capacity limit and have low decoding complexity. However, special requirements in the quantum setting severely limit the structures of turbo product codes (QTPCs). To design a good structure for QTPCs, we present a new construction of QTPCs with the interleaved serial concatenation of CSS(L1,L2)-type quantum convolutional codes (QCCs). First, CSS(L1,L2)-type QCCs are proposed by exploiting the theory of CSS-type quantum stabilizer codes and QCCs, and the description and the analysis of encoder circuit are greatly simplified in the form of Hadamard gates and C-NOT gates. Second, the interleaved coded matrix of QTPCs is derived by quantum permutation SWAP gate definition. Finally, we prove the corresponding relation on the minimum Hamming distance of QTPCs associated with classical TPCs, and describe the state diagram of encoder and decoder of QTPCs that have a highly regular structure and simple design idea.

  8. Dress Codes for Teachers.

    ERIC Educational Resources Information Center

    Phay, Robert E.

    1979-01-01

    Reviews Second Circuit Court of Appeals decision upholding right of school boards to adopt "reasonable" regulations governing teacher dress or hairstyle. Case offers the most exhaustive judicial examination of the issue to date. (Author/PKP)

  9. Leakage Suppression in the Toric Code

    NASA Astrophysics Data System (ADS)

    Suchara, Martin; Cross, Andrew; Gambetta, Jay

    2015-03-01

    Quantum codes excel at correcting local noise but fail to correct leakage faults that excite qubits to states outside the computational space. Aliferis and Terhal have shown that an accuracy threshold exists for leakage faults using gadgets called leakage reduction units (LRUs). However, these gadgets reduce the threshold and increase experimental complexity, and the costs have not been thoroughly understood. We explore a variety of techniques for leakage resilience in topological codes. Our contributions are threefold. First, we develop a leakage model that differs in critical details from earlier models. Second, we use Monte-Carlo simulations to survey several syndrome extraction circuits. Third, given the capability to perform 3-outcome measurements, we present a dramatically improved syndrome processing algorithm. Our simulations show that simple circuits with one extra CNOT per qubit reduce the accuracy threshold by less than a factor of 4 when leakage and depolarizing noise rates are comparable. This becomes a factor of 2 when the decoder uses 3-outcome measurements. Finally, when the physical error rate is less than 2 ×10-4 , placing LRUs after every gate may achieve the lowest logical error rate. We expect that the ideas may generalize to other topological codes.

  10. Software Certification - Coding, Code, and Coders

    NASA Technical Reports Server (NTRS)

    Havelund, Klaus; Holzmann, Gerard J.

    2011-01-01

    We describe a certification approach for software development that has been adopted at our organization. JPL develops robotic spacecraft for the exploration of the solar system. The flight software that controls these spacecraft is considered to be mission critical. We argue that the goal of a software certification process cannot be the development of "perfect" software, i.e., software that can be formally proven to be correct under all imaginable and unimaginable circumstances. More realistically, the goal is to guarantee a software development process that is conducted by knowledgeable engineers, who follow generally accepted procedures to control known risks, while meeting agreed upon standards of workmanship. We target three specific issues that must be addressed in such a certification procedure: the coding process, the code that is developed, and the skills of the coders. The coding process is driven by standards (e.g., a coding standard) and tools. The code is mechanically checked against the standard with the help of state-of-the-art static source code analyzers. The coders, finally, are certified in on-site training courses that include formal exams.

  11. 46 CFR 28.365 - Overcurrent protection and switched circuits.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... a steering circuit, each circuit must be protected against both overload and short circuit. Each overcurrent device in a steering system power and control circuit must provide short circuit protection...

  12. 46 CFR 28.365 - Overcurrent protection and switched circuits.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... a steering circuit, each circuit must be protected against both overload and short circuit. Each overcurrent device in a steering system power and control circuit must provide short circuit protection...

  13. 46 CFR 28.365 - Overcurrent protection and switched circuits.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... a steering circuit, each circuit must be protected against both overload and short circuit. Each overcurrent device in a steering system power and control circuit must provide short circuit protection...

  14. 46 CFR 28.365 - Overcurrent protection and switched circuits.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... a steering circuit, each circuit must be protected against both overload and short circuit. Each overcurrent device in a steering system power and control circuit must provide short circuit protection...

  15. 46 CFR 28.365 - Overcurrent protection and switched circuits.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... a steering circuit, each circuit must be protected against both overload and short circuit. Each overcurrent device in a steering system power and control circuit must provide short circuit protection...

  16. 49 CFR 236.5 - Design of control circuits on closed circuit principle.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Design of control circuits on closed circuit..., AND APPLIANCES Rules and Instructions: All Systems General § 236.5 Design of control circuits on closed circuit principle. All control circuits the functioning of which affects safety of train...

  17. 30 CFR 77.800 - High-voltage circuits; circuit breakers.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false High-voltage circuits; circuit breakers. 77.800... COAL MINES Surface High-Voltage Distribution § 77.800 High-voltage circuits; circuit breakers. High-voltage circuits supplying power to portable or mobile equipment shall be protected by suitable...

  18. 30 CFR 75.518 - Electric equipment and circuits; overload and short circuit protection.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Electric equipment and circuits; overload and... Equipment-General § 75.518 Electric equipment and circuits; overload and short circuit protection. Automatic... electric equipment and circuits against short circuit and overloads. Three-phase motors on all...

  19. 30 CFR 75.518 - Electric equipment and circuits; overload and short circuit protection.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Electric equipment and circuits; overload and... Equipment-General § 75.518 Electric equipment and circuits; overload and short circuit protection. Automatic... electric equipment and circuits against short circuit and overloads. Three-phase motors on all...

  20. 30 CFR 75.518 - Electric equipment and circuits; overload and short circuit protection.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Electric equipment and circuits; overload and... Equipment-General § 75.518 Electric equipment and circuits; overload and short circuit protection. Automatic... electric equipment and circuits against short circuit and overloads. Three-phase motors on all...

  1. 30 CFR 75.518 - Electric equipment and circuits; overload and short circuit protection.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Electric equipment and circuits; overload and... Equipment-General § 75.518 Electric equipment and circuits; overload and short circuit protection. Automatic... electric equipment and circuits against short circuit and overloads. Three-phase motors on all...

  2. 30 CFR 75.518 - Electric equipment and circuits; overload and short circuit protection.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Electric equipment and circuits; overload and... Equipment-General § 75.518 Electric equipment and circuits; overload and short circuit protection. Automatic... electric equipment and circuits against short circuit and overloads. Three-phase motors on all...

  3. XSOR codes users manual

    SciTech Connect

    Jow, Hong-Nian; Murfin, W.B.; Johnson, J.D.

    1993-11-01

    This report describes the source term estimation codes, XSORs. The codes are written for three pressurized water reactors (Surry, Sequoyah, and Zion) and two boiling water reactors (Peach Bottom and Grand Gulf). The ensemble of codes has been named ``XSOR``. The purpose of XSOR codes is to estimate the source terms which would be released to the atmosphere in severe accidents. A source term includes the release fractions of several radionuclide groups, the timing and duration of releases, the rates of energy release, and the elevation of releases. The codes have been developed by Sandia National Laboratories for the US Nuclear Regulatory Commission (NRC) in support of the NUREG-1150 program. The XSOR codes are fast running parametric codes and are used as surrogates for detailed mechanistic codes. The XSOR codes also provide the capability to explore the phenomena and their uncertainty which are not currently modeled by the mechanistic codes. The uncertainty distributions of input parameters may be used by an. XSOR code to estimate the uncertainty of source terms.

  4. DLLExternalCode

    SciTech Connect

    Greg Flach, Frank Smith

    2014-05-14

    DLLExternalCode is the a general dynamic-link library (DLL) interface for linking GoldSim (www.goldsim.com) with external codes. The overall concept is to use GoldSim as top level modeling software with interfaces to external codes for specific calculations. The DLLExternalCode DLL that performs the linking function is designed to take a list of code inputs from GoldSim, create an input file for the external application, run the external code, and return a list of outputs, read from files created by the external application, back to GoldSim. Instructions for creating the input file, running the external code, and reading the output are contained in an instructions file that is read and interpreted by the DLL.

  5. Defeating the coding monsters.

    PubMed

    Colt, Ross

    2007-02-01

    Accuracy in coding is rapidly becoming a required skill for military health care providers. Clinic staffing, equipment purchase decisions, and even reimbursement will soon be based on the coding data that we provide. Learning the complicated myriad of rules to code accurately can seem overwhelming. However, the majority of clinic visits in a typical outpatient clinic generally fall into two major evaluation and management codes, 99213 and 99214. If health care providers can learn the rules required to code a 99214 visit, then this will provide a 90% solution that can enable them to accurately code the majority of their clinic visits. This article demonstrates a step-by-step method to code a 99214 visit, by viewing each of the three requirements as a monster to be defeated.

  6. Introduction to lethal circuit transformations

    NASA Astrophysics Data System (ADS)

    Fišer, Petr; Schmidt, Jan

    2015-12-01

    Logic optimization is a process that takes a logic circuit description (Boolean network) as an input and tries to refine it, to reduce its size and/or depth. An ideal optimization process should be able to devise an optimum implementation of a network in a reasonable time, given any circuit structure at the input. However, there are cases where it completely fails to produce even near-optimum solutions. Such cases are typically induced by non-standard circuit structure modifications. Surprisingly enough, such deviated structures are frequently present in standard benchmark sets too. We may only wonder whether it is an intention of the benchmarks creators, or just an unlucky coincidence. Even though synthesis tools should be primarily well suited for practical circuits, there is no guarantee that, e.g., a higher-level synthesis process will not generate such unlucky structures. Here we present examples of circuit transformations that lead to failure of most of state-of-the-art logic synthesis and optimization processes, both academic and commercial, and suggest actions to mitigate the disturbing effects.

  7. Dynamical compensation in physiological circuits.

    PubMed

    Karin, Omer; Swisa, Avital; Glaser, Benjamin; Dor, Yuval; Alon, Uri

    2016-11-08

    Biological systems can maintain constant steady-state output despite variation in biochemical parameters, a property known as exact adaptation. Exact adaptation is achieved using integral feedback, an engineering strategy that ensures that the output of a system robustly tracks its desired value. However, it is unclear how physiological circuits also keep their output dynamics precise-including the amplitude and response time to a changing input. Such robustness is crucial for endocrine and neuronal homeostatic circuits because they need to provide a precise dynamic response in the face of wide variation in the physiological parameters of their target tissues; how such circuits compensate their dynamics for unavoidable natural fluctuations in parameters is unknown. Here, we present a design principle that provides the desired robustness, which we call dynamical compensation (DC). We present a class of circuits that show DC by means of a nonlinear feedback loop in which the regulated variable controls the functional mass of the controlling endocrine or neuronal tissue. This mechanism applies to the control of blood glucose by insulin and explains several experimental observations on insulin resistance. We provide evidence that this mechanism may also explain compensation and organ size control in other physiological circuits.

  8. Logic circuits from zero forcing.

    PubMed

    Burgarth, Daniel; Giovannetti, Vittorio; Hogben, Leslie; Severini, Simone; Young, Michael

    We design logic circuits based on the notion of zero forcing on graphs; each gate of the circuits is a gadget in which zero forcing is performed. We show that such circuits can evaluate every monotone Boolean function. By using two vertices to encode each logical bit, we obtain universal computation. We also highlight a phenomenon of "back forcing" as a property of each function. Such a phenomenon occurs in a circuit when the input of gates which have been already used at a given time step is further modified by a computation actually performed at a later stage. Finally, we show that zero forcing can be also used to implement reversible computation. The model introduced here provides a potentially new tool in the analysis of Boolean functions, with particular attention to monotonicity. Moreover, in the light of applications of zero forcing in quantum mechanics, the link with Boolean functions may suggest a new directions in quantum control theory and in the study of engineered quantum spin systems. It is an open technical problem to verify whether there is a link between zero forcing and computation with contact circuits.

  9. Normal development of brain circuits.

    PubMed

    Tau, Gregory Z; Peterson, Bradley S

    2010-01-01

    Spanning functions from the simplest reflex arc to complex cognitive processes, neural circuits have diverse functional roles. In the cerebral cortex, functional domains such as visual processing, attention, memory, and cognitive control rely on the development of distinct yet interconnected sets of anatomically distributed cortical and subcortical regions. The developmental organization of these circuits is a remarkably complex process that is influenced by genetic predispositions, environmental events, and neuroplastic responses to experiential demand that modulates connectivity and communication among neurons, within individual brain regions and circuits, and across neural pathways. Recent advances in neuroimaging and computational neurobiology, together with traditional investigational approaches such as histological studies and cellular and molecular biology, have been invaluable in improving our understanding of these developmental processes in humans in both health and illness. To contextualize the developmental origins of a wide array of neuropsychiatric illnesses, this review describes the development and maturation of neural circuits from the first synapse through critical periods of vulnerability and opportunity to the emergent capacity for cognitive and behavioral regulation, and finally the dynamic interplay across levels of circuit organization and developmental epochs.

  10. Digital first order hold circuit

    NASA Technical Reports Server (NTRS)

    Chan, Fred N. (Inventor); Wensley, Gerald J. (Inventor)

    1989-01-01

    There is provided a digitally controlled first order hold circuit and waveform synthesizer for digitally controlling the representation of a function over an approximation interval. In accordance with the operation of the invention, the first order hold circuit and waveform generator receives a digital data input signal which contains initial condition data, up/down data, and slope data for the approximation interval. The initial condition data is loaded into an up/down counter which is incremented using counting data at a rate depending on the value of the slope data and in a direction depending on the value of the up-down data. In order to minimize delays arising from data acquistion, two frequency synthesizer circuits are provided such that one frequency synthesizer provides counting data while the other frequency synthesizer receives slope data. During alternating intervals, the other frequency synthesizer circuit provides counting data while the other circuit receives slope data. In addition, long length data input signals covering a plurality of approximation intervals are provided to reduce the demands on a main system central processing unit.

  11. An Integrated Magnetic Circuit Model and Finite Element Model Approach to Magnetic Bearing Design

    NASA Technical Reports Server (NTRS)

    Provenza, Andrew J.; Kenny, Andrew; Palazzolo, Alan B.

    2003-01-01

    A code for designing magnetic bearings is described. The code generates curves from magnetic circuit equations relating important bearing performance parameters. Bearing parameters selected from the curves by a designer to meet the requirements of a particular application are input directly by the code into a three-dimensional finite element analysis preprocessor. This means that a three-dimensional computer model of the bearing being developed is immediately available for viewing. The finite element model solution can be used to show areas of magnetic saturation and make more accurate predictions of the bearing load capacity, current stiffness, position stiffness, and inductance than the magnetic circuit equations did at the start of the design process. In summary, the code combines one-dimensional and three-dimensional modeling methods for designing magnetic bearings.

  12. Nuclear sensor signal processing circuit

    DOEpatents

    Kallenbach, Gene A.; Noda, Frank T.; Mitchell, Dean J.; Etzkin, Joshua L.

    2007-02-20

    An apparatus and method are disclosed for a compact and temperature-insensitive nuclear sensor that can be calibrated with a non-hazardous radioactive sample. The nuclear sensor includes a gamma ray sensor that generates tail pulses from radioactive samples. An analog conditioning circuit conditions the tail-pulse signals from the gamma ray sensor, and a tail-pulse simulator circuit generates a plurality of simulated tail-pulse signals. A computer system processes the tail pulses from the gamma ray sensor and the simulated tail pulses from the tail-pulse simulator circuit. The nuclear sensor is calibrated under the control of the computer. The offset is adjusted using the simulated tail pulses. Since the offset is set to zero or near zero, the sensor gain can be adjusted with a non-hazardous radioactive source such as, for example, naturally occurring radiation and potassium chloride.

  13. Chua's Circuit: Control and Synchronization

    NASA Astrophysics Data System (ADS)

    Irimiciuc, Stefan-Andrei; Vasilovici, Ovidiu; Dimitriu, Dan-Gheorghe

    Chaos-based data encryption is one of the most reliable methods used in secure communications. This implies a good control of a chaotic system and a good synchronization between the involved systems. Here, experimental results are shown on the control and synchronization of Chua's circuits. The control of the chaotic circuit was achieved by using the switching method. The influence of the control signal characteristics (amplitude, frequency and shape) on the system's states was also investigated. The synchronization of two similar chaotic circuits was studied, emphasizing the importance of the chaotic state characteristics of the Master system in respect to those of Slave system. It was shown that the synchronization does not depend on the chaotic state type, neither on the dimension (x, y or z) used for synchronization.

  14. Vertically Integrated Circuits at Fermilab

    SciTech Connect

    Deptuch, Grzegorz; Demarteau, Marcel; Hoff, James; Lipton, Ronald; Shenai, Alpana; Trimpl, Marcel; Yarema, Raymond; Zimmerman, Tom; /Fermilab

    2010-01-01

    The exploration of vertically integrated circuits, also commonly known as 3D-IC technology, for applications in radiation detection started at Fermilab in 2006. This paper examines the opportunities that vertical integration offers by looking at various 3D designs that have been completed by Fermilab. The emphasis is on opportunities that are presented by through silicon vias (TSV), wafer and circuit thinning, and finally fusion bonding techniques to replace conventional bump bonding. Early work by Fermilab has led to an international consortium for the development of 3D-IC circuits for High Energy Physics. For the first time, Fermilab has organized a 3D MPW run, to which more than 25 different designs have been submitted by the consortium.

  15. Vertically Integrated Circuits at Fermilab

    SciTech Connect

    Deptuch, Grzegorz; Demarteau, Marcel; Hoff, James; Lipton, Ronald; Shenai, Alpana; Trimpl, Marcel; Yarema, Raymond; Zimmerman, Tom; /Fermilab

    2009-01-01

    The exploration of the vertically integrated circuits, also commonly known as 3D-IC technology, for applications in radiation detection started at Fermilab in 2006. This paper examines the opportunities that vertical integration offers by looking at various 3D designs that have been completed by Fermilab. The emphasis is on opportunities that are presented by through silicon vias (TSV), wafer and circuit thinning and finally fusion bonding techniques to replace conventional bump bonding. Early work by Fermilab has led to an international consortium for the development of 3D-IC circuits for High Energy Physics. The consortium has submitted over 25 different designs for the Fermilab organized MPW run organized for the first time.

  16. Additive manufacturing of hybrid circuits

    SciTech Connect

    Bell, Nelson S.; Sarobol, Pylin; Cook, Adam; Clem, Paul G.; Keicher, David M.; Hirschfeld, Deidre; Hall, Aaron Christopher

    2016-03-26

    There is a rising interest in developing functional electronics using additively manufactured components. Considerations in materials selection and pathways to forming hybrid circuits and devices must demonstrate useful electronic function; must enable integration; and must complement the complex shape, low cost, high volume, and high functionality of structural but generally electronically passive additively manufactured components. This article reviews several emerging technologies being used in industry and research/development to provide integration advantages of fabricating multilayer hybrid circuits or devices. First, we review a maskless, noncontact, direct write (DW) technology that excels in the deposition of metallic colloid inks for electrical interconnects. Second, we review a complementary technology, aerosol deposition (AD), which excels in the deposition of metallic and ceramic powder as consolidated, thick conformal coatings and is additionally patternable through masking. As a result, we show examples of hybrid circuits/devices integrated beyond 2-D planes, using combinations of DW or AD processes and conventional, established processes.

  17. Encoding entanglement-assisted quantum stabilizer codes

    NASA Astrophysics Data System (ADS)

    Wang, Yun-Jiang; Bai, Bao-Ming; Li, Zhuo; Peng, Jin-Ye; Xiao, He-Ling

    2012-02-01

    We address the problem of encoding entanglement-assisted (EA) quantum error-correcting codes (QECCs) and of the corresponding complexity. We present an iterative algorithm from which a quantum circuit composed of CNOT, H, and S gates can be derived directly with complexity O(n2) to encode the qubits being sent. Moreover, we derive the number of each gate consumed in our algorithm according to which we can design EA QECCs with low encoding complexity. Another advantage brought by our algorithm is the easiness and efficiency of programming on classical computers.

  18. Architecture of enteric neural circuits involved in intestinal motility.

    PubMed

    Costa, M; Brookes, S H

    2008-08-01

    This short review describes the conceptual development in the search for the enteric neural circuits with the initial identifications of the classes of enteric neurons on the bases of their morphology, neurochemistry, biophysical properties, projections and connectivity. The discovery of the presence of multiple neurochemicals in the same nerve cells in specific combinations led to the concept of "chemical coding" and of "plurichemical transmission". The proposal that enteric reflexes are largely responsible for the propulsion of contents led to investigations of polarised reflex pathways and how these may be activated to generate the coordinated propulsive behaviour of the intestine. The research over the past decades attempted to integrate information of chemical neuroanatomy with functional studies, with the development of methods combining anatomical, functional and pharmacological techniques. This multidisciplinary strategy led to a full accounting of all functional classes of enteric neurons in the guinea-pig, and advanced wiring diagrams of the enteric neural circuits have been proposed. In parallel, investigations of the actual behaviour of the intestine during physiological motor activity have advanced with the development of spatio-temporal analysis from video recordings. The relation between neural pathways, their activities and the generation of patterns of motor activity remain largely unexplained. The enteric neural circuits appear not set in rigid programs but respond to different physico-chemical contents in an adaptable way (neuromechanical hypothesis). The generation of the complex repertoire of motor patterns results from the interplay of myogenic and neuromechanical mechanisms with spontaneous generation of migratory motor activity by enteric circuits.

  19. Programming languages for circuit design.

    PubMed

    Pedersen, Michael; Yordanov, Boyan

    2015-01-01

    This chapter provides an overview of a programming language for Genetic Engineering of Cells (GEC). A GEC program specifies a genetic circuit at a high level of abstraction through constraints on otherwise unspecified DNA parts. The GEC compiler then selects parts which satisfy the constraints from a given parts database. GEC further provides more conventional programming language constructs for abstraction, e.g., through modularity. The GEC language and compiler is available through a Web tool which also provides functionality, e.g., for simulation of designed circuits.

  20. A general waveguide circuit theory

    NASA Astrophysics Data System (ADS)

    Marks, Roger B.; Williams, Dylan F.

    1992-10-01

    This work generalizes and extends the classical circuit theory of electromagnetic waveguides. Unlike the conventional theory, the present formulation applies to all waveguides composed of linear, isotropic material, even those involving lossy conductors and hybrid mode fields, in a fully rigorous way. Special attention is given to distinguishing the traveling waves, constructed with respect to a well-defined characteristic impedance, from a set of pseudo-waves, defined with respect to an arbitrary reference impedance. Matrices characterizing a linear circuit are defined, and relationships among them, some newly discovered, are derived. New ramifications of reciprocity are developed. Measurement of various network parameters is given extensive treatment.

  1. Circuit breaker lock out assembly

    DOEpatents

    Gordy, W.T.

    1983-05-18

    A lock out assembly for a circuit breaker which consists of a generally step-shaped unitary base with an aperture in the small portion of the step-shaped base and a roughly S shaped retaining pin which loops through the large portion of the step-shaped base. The lock out assembly is adapted to fit over a circuit breaker with the handle switch projecting through the aperture, and the retaining pin projecting into an opening of the handle switch, preventing removal.

  2. Retropath: automated pipeline for embedded metabolic circuits.

    PubMed

    Carbonell, Pablo; Parutto, Pierre; Baudier, Claire; Junot, Christophe; Faulon, Jean-Loup

    2014-08-15

    Metabolic circuits are a promising alternative to other conventional genetic circuits as modular parts implementing functionalities required for synthetic biology applications. To date, metabolic design has been mainly focused on production circuits. Emergent applications such as smart therapeutics, however, require circuits that enable sensing and regulation. Here, we present RetroPath, an automated pipeline for embedded metabolic circuits that explores the circuit design space from a given set of specifications and selects the best circuits to implement based on desired constraints. Synthetic biology circuits embedded in a chassis organism that are capable of controlling the production, processing, sensing, and the release of specific molecules were enumerated in the metabolic space through a standard procedure. In that way, design and implementation of applications such as therapeutic circuits that autonomously diagnose and treat disease, are enabled, and their optimization is streamlined.

  3. Mechanical code comparator

    DOEpatents

    Peter, Frank J.; Dalton, Larry J.; Plummer, David W.

    2002-01-01

    A new class of mechanical code comparators is described which have broad potential for application in safety, surety, and security applications. These devices can be implemented as micro-scale electromechanical systems that isolate a secure or otherwise controlled device until an access code is entered. This access code is converted into a series of mechanical inputs to the mechanical code comparator, which compares the access code to a pre-input combination, entered previously into the mechanical code comparator by an operator at the system security control point. These devices provide extremely high levels of robust security. Being totally mechanical in operation, an access control system properly based on such devices cannot be circumvented by software attack alone.

  4. More box codes

    NASA Technical Reports Server (NTRS)

    Solomon, G.

    1992-01-01

    A new investigation shows that, starting from the BCH (21,15;3) code represented as a 7 x 3 matrix and adding a row and column to add even parity, one obtains an 8 x 4 matrix (32,15;8) code. An additional dimension is obtained by specifying odd parity on the rows and even parity on the columns, i.e., adjoining to the 8 x 4 matrix, the matrix, which is zero except for the fourth column (of all ones). Furthermore, any seven rows and three columns will form the BCH (21,15;3) code. This box code has the same weight structure as the quadratic residue and BCH codes of the same dimensions. Whether there exists an algebraic isomorphism to either code is as yet unknown.

  5. Generating code adapted for interlinking legacy scalar code and extended vector code

    DOEpatents

    Gschwind, Michael K

    2013-06-04

    Mechanisms for intermixing code are provided. Source code is received for compilation using an extended Application Binary Interface (ABI) that extends a legacy ABI and uses a different register configuration than the legacy ABI. First compiled code is generated based on the source code, the first compiled code comprising code for accommodating the difference in register configurations used by the extended ABI and the legacy ABI. The first compiled code and second compiled code are intermixed to generate intermixed code, the second compiled code being compiled code that uses the legacy ABI. The intermixed code comprises at least one call instruction that is one of a call from the first compiled code to the second compiled code or a call from the second compiled code to the first compiled code. The code for accommodating the difference in register configurations is associated with the at least one call instruction.

  6. Deciphering Neural Codes of Memory during Sleep.

    PubMed

    Chen, Zhe; Wilson, Matthew A

    2017-04-05

    Memories of experiences are stored in the cerebral cortex. Sleep is critical for the consolidation of hippocampal memory of wake experiences into the neocortex. Understanding representations of neural codes of hippocampal-neocortical networks during sleep would reveal important circuit mechanisms in memory consolidation and provide novel insights into memory and dreams. Although sleep-associated ensemble spike activity has been investigated, identifying the content of memory in sleep remains challenging. Here we revisit important experimental findings on sleep-associated memory (i.e., neural activity patterns in sleep that reflect memory processing) and review computational approaches to the analysis of sleep-associated neural codes (SANCs). We focus on two analysis paradigms for sleep-associated memory and propose a new unsupervised learning framework ('memory first, meaning later') for unbiased assessment of SANCs.

  7. Regulation of spike timing in visual cortical circuits

    PubMed Central

    Tiesinga, Paul; Fellous, Jean-Marc; Sejnowski, Terrence J.

    2010-01-01

    A train of action potentials (a spike train) can carry information in both the average firing rate and the pattern of spikes in the train. But can such a spike-pattern code be supported by cortical circuits? Neurons in vitro produce a spike pattern in response to the injection of a fluctuating current. However, cortical neurons in vivo are modulated by local oscillatory neuronal activity and by top-down inputs. In a cortical circuit, precise spike patterns thus reflect the interaction between internally generated activity and sensory information encoded by input spike trains. We review the evidence for precise and reliable spike timing in the cortex and discuss its computational role. PMID:18200026

  8. Industrial Computer Codes

    NASA Technical Reports Server (NTRS)

    Shapiro, Wilbur

    1996-01-01

    This is an overview of new and updated industrial codes for seal design and testing. GCYLT (gas cylindrical seals -- turbulent), SPIRALI (spiral-groove seals -- incompressible), KTK (knife to knife) Labyrinth Seal Code, and DYSEAL (dynamic seal analysis) are covered. CGYLT uses G-factors for Poiseuille and Couette turbulence coefficients. SPIRALI is updated to include turbulence and inertia, but maintains the narrow groove theory. KTK labyrinth seal code handles straight or stepped seals. And DYSEAL provides dynamics for the seal geometry.

  9. Phonological coding during reading

    PubMed Central

    Leinenger, Mallorie

    2014-01-01

    The exact role that phonological coding (the recoding of written, orthographic information into a sound based code) plays during silent reading has been extensively studied for more than a century. Despite the large body of research surrounding the topic, varying theories as to the time course and function of this recoding still exist. The present review synthesizes this body of research, addressing the topics of time course and function in tandem. The varying theories surrounding the function of phonological coding (e.g., that phonological codes aid lexical access, that phonological codes aid comprehension and bolster short-term memory, or that phonological codes are largely epiphenomenal in skilled readers) are first outlined, and the time courses that each maps onto (e.g., that phonological codes come online early (pre-lexical) or that phonological codes come online late (post-lexical)) are discussed. Next the research relevant to each of these proposed functions is reviewed, discussing the varying methodologies that have been used to investigate phonological coding (e.g., response time methods, reading while eyetracking or recording EEG and MEG, concurrent articulation) and highlighting the advantages and limitations of each with respect to the study of phonological coding. In response to the view that phonological coding is largely epiphenomenal in skilled readers, research on the use of phonological codes in prelingually, profoundly deaf readers is reviewed. Finally, implications for current models of word identification (activation-verification model (Van Order, 1987), dual-route model (e.g., Coltheart, Rastle, Perry, Langdon, & Ziegler, 2001), parallel distributed processing model (Seidenberg & McClelland, 1989)) are discussed. PMID:25150679

  10. Tokamak Systems Code

    SciTech Connect

    Reid, R.L.; Barrett, R.J.; Brown, T.G.; Gorker, G.E.; Hooper, R.J.; Kalsi, S.S.; Metzler, D.H.; Peng, Y.K.M.; Roth, K.E.; Spampinato, P.T.

    1985-03-01

    The FEDC Tokamak Systems Code calculates tokamak performance, cost, and configuration as a function of plasma engineering parameters. This version of the code models experimental tokamaks. It does not currently consider tokamak configurations that generate electrical power or incorporate breeding blankets. The code has a modular (or subroutine) structure to allow independent modeling for each major tokamak component or system. A primary benefit of modularization is that a component module may be updated without disturbing the remainder of the systems code as long as the imput to or output from the module remains unchanged.

  11. Topological subsystem codes

    SciTech Connect

    Bombin, H.

    2010-03-15

    We introduce a family of two-dimensional (2D) topological subsystem quantum error-correcting codes. The gauge group is generated by two-local Pauli operators, so that two-local measurements are enough to recover the error syndrome. We study the computational power of code deformation in these codes and show that boundaries cannot be introduced in the usual way. In addition, we give a general mapping connecting suitable classical statistical mechanical models to optimal error correction in subsystem stabilizer codes that suffer from depolarizing noise.

  12. FAA Smoke Transport Code

    SciTech Connect

    Domino, Stefan; Luketa-Hanlin, Anay; Gallegos, Carlos

    2006-10-27

    FAA Smoke Transport Code, a physics-based Computational Fluid Dynamics tool, which couples heat, mass, and momentum transfer, has been developed to provide information on smoke transport in cargo compartments with various geometries and flight conditions. The software package contains a graphical user interface for specification of geometry and boundary conditions, analysis module for solving the governing equations, and a post-processing tool. The current code was produced by making substantial improvements and additions to a code obtained from a university. The original code was able to compute steady, uniform, isothermal turbulent pressurization. In addition, a preprocessor and postprocessor were added to arrive at the current software package.

  13. Transonic airfoil codes

    NASA Technical Reports Server (NTRS)

    Garabedian, P. R.

    1979-01-01

    Computer codes for the design and analysis of transonic airfoils are considered. The design code relies on the method of complex characteristics in the hodograph plane to construct shockless airfoil. The analysis code uses artificial viscosity to calculate flows with weak shock waves at off-design conditions. Comparisons with experiments show that an excellent simulation of two dimensional wind tunnel tests is obtained. The codes have been widely adopted by the aircraft industry as a tool for the development of supercritical wing technology.

  14. MOS integrated circuit fault modeling

    NASA Technical Reports Server (NTRS)

    Sievers, M.

    1985-01-01

    Three digital simulation techniques for MOS integrated circuit faults were examined. These techniques embody a hierarchy of complexity bracketing the range of simulation levels. The digital approaches are: transistor-level, connector-switch-attenuator level, and gate level. The advantages and disadvantages are discussed. Failure characteristics are also described.

  15. Variable magnetic circuit torque sensor

    NASA Astrophysics Data System (ADS)

    Lemarquand, G.; Lemarquand, V.

    1991-11-01

    This paper presents an original torque sensor structure using the properties of magnetic circuits, including permanent magnets. The torque is measured through the torsion of the transmitting shaft. The torsion is proportional to the torque. Considering two points of the shaft on the same line in absence of torque, the information is given by the twisting angle in the presence of a torque. A rotating magnetic circuit yields an angle representative signal. This circuit is deformed by the shaft torsion. The reluctance varies and so does the magnet operating point. The induction is measured in an airgap by a statoric galvanomagnetic device. The magnetic field source is an axial permanent magnet ring. Two iron-toothed rings, fixed to the driving and driven part of the shaft, respectively, and separated by an airgap make up the variable part of the magnetic circuit. The teeth get out of line whenever a torque is applied. The galvanomagnetic device measures an uniform induction and so delivers a modulation free signal, i.e., rotation independent. Because of the periodic toothed structure, the induction varies periodically with the twisting angle. The sense of the variation is the same over half a period or half a pitch. The variation form depends on the teeth design. Operating interval is to be chosen equal to or smaller than the half pitch.

  16. Circuit theory of Andreev conductance

    NASA Astrophysics Data System (ADS)

    Nazarov, Yuli V.

    1994-09-01

    Conductance of small normal metal structures adjacent to a superconductor is determined by coherent Andreev reflection. We show that under certain limitations the conductance can be found by means of an extended circuit theory. The theory deals with two types of elements: tunnel junctions and diffusive conductors and provides the basis for practical calculations. A new device proposed illustrates the advantages of the theory.

  17. Integrated Circuit Stellar Magnitude Simulator

    ERIC Educational Resources Information Center

    Blackburn, James A.

    1978-01-01

    Describes an electronic circuit which can be used to demonstrate the stellar magnitude scale. Six rectangular light-emitting diodes with independently adjustable duty cycles represent stars of magnitudes 1 through 6. Experimentally verifies the logarithmic response of the eye. (Author/GA)

  18. Advanced Imaging of Elementary Circuits

    ERIC Educational Resources Information Center

    Baird, William H.; Richards, Caleb; Godbole, Pranav

    2012-01-01

    Students commonly find the second semester of introductory physics to be more challenging than the first, probably due to the mechanical intuition we acquire just by moving around. For most students, there is no similar comfort with electricity or magnetism. In an effort to combat this confusion, we decided to examine simple electric circuits with…

  19. No-warp potted circuits

    NASA Technical Reports Server (NTRS)

    Robinson, W. W.

    1979-01-01

    Sponge inserts compensate for potting-compound expansion and relieve thermal stresses on circuit boards. Technique quality of production runs on PC boards intended for applications in environments less severe than those for aerospace equipment. Pads reduce weight of modules because they weigh far less than potting compound they displace.

  20. Low-frequency attenuator circuit

    NASA Technical Reports Server (NTRS)

    Cash, W. H., Jr.; Polyhemus, J. T.

    1979-01-01

    Circuit uses only single operational amplifier and few passive components to remove background noise from miniature "wristwatch" pulse detector. It can be applied to other systems where background noise is slowly varying, such as ultrasonics, strain-gage sensors, and accelerometers.

  1. Development of CMOS integrated circuits

    NASA Technical Reports Server (NTRS)

    Bertino, F.; Feller, A.; Greenhouse, J.; Lombardi, T.; Merriam, A.; Noto, R.; Ozga, S.; Pryor, R.; Ramondetta, P.; Smith, A.

    1979-01-01

    Report documents life cycles of two custom CMOS integrated circuits: (1) 4-bit multiplexed register with shift left and shift right capabilities, and (2) dual 4-bit registers. Cycles described include conception as logic diagrams through design, fabrication, testing, and delivery.

  2. View of first bank of circuit towers on Arizona side ...

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

    View of first bank of circuit towers on Arizona side of canyon. Left tower supports Circuit 12, second from left tower supports Circuit 11, middle tower supports Circuit 10, second from right tower supports Circuit 9, and right tower supports Circuit 8, view west - Hoover Dam, Circuits 1-15, U.S. Highway 93, Boulder City, Clark County, NV

  3. Fast Coding Unit Encoding Mechanism for Low Complexity Video Coding

    PubMed Central

    Wu, Yueying; Jia, Kebin; Gao, Guandong

    2016-01-01

    In high efficiency video coding (HEVC), coding tree contributes to excellent compression performance. However, coding tree brings extremely high computational complexity. Innovative works for improving coding tree to further reduce encoding time are stated in this paper. A novel low complexity coding tree mechanism is proposed for HEVC fast coding unit (CU) encoding. Firstly, this paper makes an in-depth study of the relationship among CU distribution, quantization parameter (QP) and content change (CC). Secondly, a CU coding tree probability model is proposed for modeling and predicting CU distribution. Eventually, a CU coding tree probability update is proposed, aiming to address probabilistic model distortion problems caused by CC. Experimental results show that the proposed low complexity CU coding tree mechanism significantly reduces encoding time by 27% for lossy coding and 42% for visually lossless coding and lossless coding. The proposed low complexity CU coding tree mechanism devotes to improving coding performance under various application conditions. PMID:26999741

  4. Fast Coding Unit Encoding Mechanism for Low Complexity Video Coding.

    PubMed

    Gao, Yuan; Liu, Pengyu; Wu, Yueying; Jia, Kebin; Gao, Guandong

    2016-01-01

    In high efficiency video coding (HEVC), coding tree contributes to excellent compression performance. However, coding tree brings extremely high computational complexity. Innovative works for improving coding tree to further reduce encoding time are stated in this paper. A novel low complexity coding tree mechanism is proposed for HEVC fast coding unit (CU) encoding. Firstly, this paper makes an in-depth study of the relationship among CU distribution, quantization parameter (QP) and content change (CC). Secondly, a CU coding tree probability model is proposed for modeling and predicting CU distribution. Eventually, a CU coding tree probability update is proposed, aiming to address probabilistic model distortion problems caused by CC. Experimental results show that the proposed low complexity CU coding tree mechanism significantly reduces encoding time by 27% for lossy coding and 42% for visually lossless coding and lossless coding. The proposed low complexity CU coding tree mechanism devotes to improving coding performance under various application conditions.

  5. Dress Codes for Teachers?

    ERIC Educational Resources Information Center

    Million, June

    2004-01-01

    In this article, the author discusses an e-mail survey of principals from across the country regarding whether or not their school had a formal staff dress code. The results indicate that most did not have a formal dress code, but agreed that professional dress for teachers was not only necessary, but showed respect for the school and had a…

  6. Lichenase and coding sequences

    DOEpatents

    Li, Xin-Liang; Ljungdahl, Lars G.; Chen, Huizhong

    2000-08-15

    The present invention provides a fungal lichenase, i.e., an endo-1,3-1,4-.beta.-D-glucanohydrolase, its coding sequence, recombinant DNA molecules comprising the lichenase coding sequences, recombinant host cells and methods for producing same. The present lichenase is from Orpinomyces PC-2.

  7. Legacy Code Modernization

    NASA Technical Reports Server (NTRS)

    Hribar, Michelle R.; Frumkin, Michael; Jin, Haoqiang; Waheed, Abdul; Yan, Jerry; Saini, Subhash (Technical Monitor)

    1998-01-01

    Over the past decade, high performance computing has evolved rapidly; systems based on commodity microprocessors have been introduced in quick succession from at least seven vendors/families. Porting codes to every new architecture is a difficult problem; in particular, here at NASA, there are many large CFD applications that are very costly to port to new machines by hand. The LCM ("Legacy Code Modernization") Project is the development of an integrated parallelization environment (IPE) which performs the automated mapping of legacy CFD (Fortran) applications to state-of-the-art high performance computers. While most projects to port codes focus on the parallelization of the code, we consider porting to be an iterative process consisting of several steps: 1) code cleanup, 2) serial optimization,3) parallelization, 4) performance monitoring and visualization, 5) intelligent tools for automated tuning using performance prediction and 6) machine specific optimization. The approach for building this parallelization environment is to build the components for each of the steps simultaneously and then integrate them together. The demonstration will exhibit our latest research in building this environment: 1. Parallelizing tools and compiler evaluation. 2. Code cleanup and serial optimization using automated scripts 3. Development of a code generator for performance prediction 4. Automated partitioning 5. Automated insertion of directives. These demonstrations will exhibit the effectiveness of an automated approach for all the steps involved with porting and tuning a legacy code application for a new architecture.

  8. Synthesizing Certified Code

    NASA Technical Reports Server (NTRS)

    Whalen, Michael; Schumann, Johann; Fischer, Bernd

    2002-01-01

    Code certification is a lightweight approach to demonstrate software quality on a formal level. Its basic idea is to require producers to provide formal proofs that their code satisfies certain quality properties. These proofs serve as certificates which can be checked independently. Since code certification uses the same underlying technology as program verification, it also requires many detailed annotations (e.g., loop invariants) to make the proofs possible. However, manually adding theses annotations to the code is time-consuming and error-prone. We address this problem by combining code certification with automatic program synthesis. We propose an approach to generate simultaneously, from a high-level specification, code and all annotations required to certify generated code. Here, we describe a certification extension of AUTOBAYES, a synthesis tool which automatically generates complex data analysis programs from compact specifications. AUTOBAYES contains sufficient high-level domain knowledge to generate detailed annotations. This allows us to use a general-purpose verification condition generator to produce a set of proof obligations in first-order logic. The obligations are then discharged using the automated theorem E-SETHEO. We demonstrate our approach by certifying operator safety for a generated iterative data classification program without manual annotation of the code.

  9. Coding Acoustic Metasurfaces.

    PubMed

    Xie, Boyang; Tang, Kun; Cheng, Hua; Liu, Zhengyou; Chen, Shuqi; Tian, Jianguo

    2017-02-01

    Coding acoustic metasurfaces can combine simple logical bits to acquire sophisticated functions in wave control. The acoustic logical bits can achieve a phase difference of exactly π and a perfect match of the amplitudes for the transmitted waves. By programming the coding sequences, acoustic metasurfaces with various functions, including creating peculiar antenna patterns and waves focusing, have been demonstrated.

  10. Computerized mega code recording.

    PubMed

    Burt, T W; Bock, H C

    1988-04-01

    A system has been developed to facilitate recording of advanced cardiac life support mega code testing scenarios. By scanning a paper "keyboard" using a bar code wand attached to a portable microcomputer, the person assigned to record the scenario can easily generate an accurate, complete, timed, and typewritten record of the given situations and the obtained responses.

  11. Pseudonoise code tracking loop

    NASA Technical Reports Server (NTRS)

    Laflame, D. T. (Inventor)

    1980-01-01

    A delay-locked loop is presented for tracking a pseudonoise (PN) reference code in an incoming communication signal. The loop is less sensitive to gain imbalances, which can otherwise introduce timing errors in the PN reference code formed by the loop.

  12. Fabric circuits and method of manufacturing fabric circuits

    NASA Technical Reports Server (NTRS)

    Chu, Andrew W. (Inventor); Dobbins, Justin A. (Inventor); Scully, Robert C. (Inventor); Trevino, Robert C. (Inventor); Lin, Greg Y. (Inventor); Fink, Patrick W. (Inventor)

    2011-01-01

    A flexible, fabric-based circuit comprises a non-conductive flexible layer of fabric and a conductive flexible layer of fabric adjacent thereto. A non-conductive thread, an adhesive, and/or other means may be used for attaching the conductive layer to the non-conductive layer. In some embodiments, the layers are attached by a computer-driven embroidery machine at pre-determined portions or locations in accordance with a pre-determined attachment layout before automated cutting. In some other embodiments, an automated milling machine or a computer-driven laser using a pre-designed circuit trace as a template cuts the conductive layer so as to separate an undesired portion of the conductive layer from a desired portion of the conductive layer. Additional layers of conductive fabric may be attached in some embodiments to form a multi-layer construct.

  13. Simple, one transistor circuit boosts pulse amplitude

    NASA Technical Reports Server (NTRS)

    Keon, T.; Matchett, M. W.

    1966-01-01

    Simple circuit that uses a single transistor to accomplish capacitor storage followed by common-base switching supplies a pulse voltage, higher than that normally available from emitter-follower circuits, to drive a 100-watt transmitter.

  14. Driver circuit for solid state light sources

    DOEpatents

    Palmer, Fred; Denvir, Kerry; Allen, Steven

    2016-02-16

    A driver circuit for a light source including one or more solid state light sources, a luminaire including the same, and a method of so driving the solid state light sources are provided. The driver circuit includes a rectifier circuit that receives an alternating current (AC) input voltage and provides a rectified AC voltage. The driver circuit also includes a switching converter circuit coupled to the light source. The switching converter circuit provides a direct current (DC) output to the light source in response to the rectified AC voltage. The driver circuit also includes a mixing circuit, coupled to the light source, to switch current through at least one solid state light source of the light source in response to each of a plurality of consecutive half-waves of the rectified AC voltage.

  15. Post regulation circuit with energy storage

    DOEpatents

    Ball, Don G.; Birx, Daniel L.; Cook, Edward G.

    1992-01-01

    A charge regulation circuit provides regulation of an unregulated voltage supply and provides energy storage. The charge regulation circuit according to the present invention provides energy storage without unnecessary dissipation of energy through a resistor as in prior art approaches.

  16. 49 CFR 236.721 - Circuit, control.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.721 Circuit, control. An electrical circuit between a source of electric energy and a device which it operates....

  17. Analog Nonvolatile Computer Memory Circuits

    NASA Technical Reports Server (NTRS)

    MacLeod, Todd

    2007-01-01

    In nonvolatile random-access memory (RAM) circuits of a proposed type, digital data would be stored in analog form in ferroelectric field-effect transistors (FFETs). This type of memory circuit would offer advantages over prior volatile and nonvolatile types: In a conventional complementary metal oxide/semiconductor static RAM, six transistors must be used to store one bit, and storage is volatile in that data are lost when power is turned off. In a conventional dynamic RAM, three transistors must be used to store one bit, and the stored bit must be refreshed every few milliseconds. In contrast, in a RAM according to the proposal, data would be retained when power was turned off, each memory cell would contain only two FFETs, and the cell could store multiple bits (the exact number of bits depending on the specific design). Conventional flash memory circuits afford nonvolatile storage, but they operate at reading and writing times of the order of thousands of conventional computer memory reading and writing times and, hence, are suitable for use only as off-line storage devices. In addition, flash memories cease to function after limited numbers of writing cycles. The proposed memory circuits would not be subject to either of these limitations. Prior developmental nonvolatile ferroelectric memories are limited to one bit per cell, whereas, as stated above, the proposed memories would not be so limited. The design of a memory circuit according to the proposal must reflect the fact that FFET storage is only partly nonvolatile, in that the signal stored in an FFET decays gradually over time. (Retention times of some advanced FFETs exceed ten years.) Instead of storing a single bit of data as either a positively or negatively saturated state in a ferroelectric device, each memory cell according to the proposal would store two values. The two FFETs in each cell would be denoted the storage FFET and the control FFET. The storage FFET would store an analog signal value

  18. Synthesis of Arbitrary Quantum Circuits to Topological Assembly

    PubMed Central

    Paler, Alexandru; Devitt, Simon J.; Fowler, Austin G.

    2016-01-01

    Given a quantum algorithm, it is highly nontrivial to devise an efficient sequence of physical gates implementing the algorithm on real hardware and incorporating topological quantum error correction. In this paper, we present a first step towards this goal, focusing on generating correct and simple arrangements of topological structures that correspond to a given quantum circuit and largely neglecting their efficiency. We detail the many challenges that will need to be tackled in the pursuit of efficiency. The software source code can be consulted at https://github.com/alexandrupaler/tqec. PMID:27481212

  19. Synthesis of Arbitrary Quantum Circuits to Topological Assembly

    NASA Astrophysics Data System (ADS)

    Paler, Alexandru; Devitt, Simon J.; Fowler, Austin G.

    2016-08-01

    Given a quantum algorithm, it is highly nontrivial to devise an efficient sequence of physical gates implementing the algorithm on real hardware and incorporating topological quantum error correction. In this paper, we present a first step towards this goal, focusing on generating correct and simple arrangements of topological structures that correspond to a given quantum circuit and largely neglecting their efficiency. We detail the many challenges that will need to be tackled in the pursuit of efficiency. The software source code can be consulted at https://github.com/alexandrupaler/tqec.

  20. Emulating Anyonic Fractional Statistical Behavior in a Superconducting Quantum Circuit.

    PubMed

    Zhong, Y P; Xu, D; Wang, P; Song, C; Guo, Q J; Liu, W X; Xu, K; Xia, B X; Lu, C-Y; Han, Siyuan; Pan, Jian-Wei; Wang, H

    2016-09-09

    Anyons are exotic quasiparticles obeying fractional statistics, whose behavior can be emulated in artificially designed spin systems. Here we present an experimental emulation of creating anyonic excitations in a superconducting circuit that consists of four qubits, achieved by dynamically generating the ground and excited states of the toric code model, i.e., four-qubit Greenberger-Horne-Zeilinger states. The anyonic braiding is implemented via single-qubit rotations: a phase shift of π related to braiding, the hallmark of Abelian 1/2 anyons, has been observed through a Ramsey-type interference measurement.

  1. Synthesis of Arbitrary Quantum Circuits to Topological Assembly.

    PubMed

    Paler, Alexandru; Devitt, Simon J; Fowler, Austin G

    2016-08-02

    Given a quantum algorithm, it is highly nontrivial to devise an efficient sequence of physical gates implementing the algorithm on real hardware and incorporating topological quantum error correction. In this paper, we present a first step towards this goal, focusing on generating correct and simple arrangements of topological structures that correspond to a given quantum circuit and largely neglecting their efficiency. We detail the many challenges that will need to be tackled in the pursuit of efficiency. The software source code can be consulted at https://github.com/alexandrupaler/tqec.

  2. Evolving genetic code

    PubMed Central

    OHAMA, Takeshi; INAGAKI, Yuji; BESSHO, Yoshitaka; OSAWA, Syozo

    2008-01-01

    In 1985, we reported that a bacterium, Mycoplasma capricolum, used a deviant genetic code, namely UGA, a “universal” stop codon, was read as tryptophan. This finding, together with the deviant nuclear genetic codes in not a few organisms and a number of mitochondria, shows that the genetic code is not universal, and is in a state of evolution. To account for the changes in codon meanings, we proposed the codon capture theory stating that all the code changes are non-disruptive without accompanied changes of amino acid sequences of proteins. Supporting evidence for the theory is presented in this review. A possible evolutionary process from the ancient to the present-day genetic code is also discussed. PMID:18941287

  3. Combustion chamber analysis code

    NASA Technical Reports Server (NTRS)

    Przekwas, A. J.; Lai, Y. G.; Krishnan, A.; Avva, R. K.; Giridharan, M. G.

    1993-01-01

    A three-dimensional, time dependent, Favre averaged, finite volume Navier-Stokes code has been developed to model compressible and incompressible flows (with and without chemical reactions) in liquid rocket engines. The code has a non-staggered formulation with generalized body-fitted-coordinates (BFC) capability. Higher order differencing methodologies such as MUSCL and Osher-Chakravarthy schemes are available. Turbulent flows can be modeled using any of the five turbulent models present in the code. A two-phase, two-liquid, Lagrangian spray model has been incorporated into the code. Chemical equilibrium and finite rate reaction models are available to model chemically reacting flows. The discrete ordinate method is used to model effects of thermal radiation. The code has been validated extensively against benchmark experimental data and has been applied to model flows in several propulsion system components of the SSME and the STME.

  4. Generating Circuit Tests by Exploiting Designed Behavior

    DTIC Science & Technology

    1988-12-01

    determine whether the circuit is in test-mode and control /AR shifting. We modified the circuit model accordingly. Figure 6.16 shows the consequences for...productive. Yehudah Freundlich opened my mind to the history and philosophy of science. He knows lots of pretty good jokes too. Glenn Kramer, Narinder...39 2.2 Modeling Circuits and Faults ...... ...................... 44 2.2.1 Circuit Models

  5. A new driving circuit for IGBT devices

    SciTech Connect

    Licitra, C.; Musumeci, S.; Raciti, A.; Galluzzo, A.U.; Letor, R.; Melito, M.

    1995-05-01

    IGBT devices are increasingly used in power electronic equipment due to their high power handling capability. This paper deals with the problems that concern the turn-on, turn-off, and short-circuit of these devices. An optimal new driving circuit is proposed which gives excellent device output performances. Experimental oscillogram traces of transient condition tests are given, which demonstrate the advantages of using the new driving circuit. The suitability of the driving circuit for integration is analyzed.

  6. Removing Bonded Integrated Circuits From Boards

    NASA Technical Reports Server (NTRS)

    Rice, John T.

    1989-01-01

    Small resistance heater makes it easier, faster, and cheaper to remove integrated circuit from hybrid-circuit board, package, or other substrate for rework. Heater, located directly in polymeric bond interface or on substrate under integrated-circuit chip, energized when necessary to remove chip. Heat generated softens adhesive or solder that bonds chip to substrate. Chip then lifted easily from substrate.

  7. Adjustable, Audible Continuity Tester For Delicate Circuits

    NASA Technical Reports Server (NTRS)

    Mcalister, William B.

    1988-01-01

    Unit adjustable to resistances up to 35 ohms. Adjustable, audible electrical-continuity tester gives audible indication. Used safely on circuit boards in which semiconductor components installed, and on complementary metal oxide/semiconductor integrated circuits. Tester compact and circuit simple. Built from inexpensive standard components.

  8. 49 CFR 234.203 - Control circuits.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Control circuits. 234.203 Section 234.203 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION..., Inspection, and Testing Maintenance Standards § 234.203 Control circuits. All control circuits that...

  9. 49 CFR 234.203 - Control circuits.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Control circuits. 234.203 Section 234.203... EMERGENCY NOTIFICATION SYSTEMS Maintenance, Inspection, and Testing Maintenance Standards § 234.203 Control circuits. All control circuits that affect the safe operation of a highway-rail grade crossing...

  10. 49 CFR 234.203 - Control circuits.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Control circuits. 234.203 Section 234.203... EMERGENCY NOTIFICATION SYSTEMS Maintenance, Inspection, and Testing Maintenance Standards § 234.203 Control circuits. All control circuits that affect the safe operation of a highway-rail grade crossing...

  11. New Logic Circuit with DC Parametric Excitation

    NASA Astrophysics Data System (ADS)

    Sugahara, Masanori; Kaneda, Hisayoshi

    1982-12-01

    It is shown that dc parametric excitation is possible in a circuit named JUDO, which is composed of two resistively-connected Josephson junctions. Simulation study proves that the circuit has large gain and properties suitable for the construction of small, high-speed logic circuits.

  12. Electronic test and calibration circuits, a compilation

    NASA Technical Reports Server (NTRS)

    1972-01-01

    A wide variety of simple test calibration circuits are compiled for the engineer and laboratory technician. The majority of circuits were found inexpensive to assemble. Testing electronic devices and components, instrument and system test, calibration and reference circuits, and simple test procedures are presented.

  13. Simple photometer circuits using modular electronic components

    NASA Technical Reports Server (NTRS)

    Wampler, J. E.

    1975-01-01

    Operational and peak holding amplifiers are discussed as useful circuits for bioluminescence assays. Circuit diagrams are provided. While analog methods can give a good integration on short time scales, digital methods were found best for long term integration in bioluminescence assays. Power supplies, a general photometer circuit with ratio capability, and variations in the basic photometer design are also considered.

  14. 49 CFR 236.719 - Circuit, acknowledgment.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Circuit, acknowledgment. 236.719 Section 236.719 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Circuit, acknowledgment. A circuit consisting of wire or other conducting material installed between...

  15. 30 CFR 57.6403 - Branch circuits.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Branch circuits. 57.6403 Section 57.6403... Blasting-Surface and Underground § 57.6403 Branch circuits. (a) If electric blasting includes the use of branch circuits, each branch shall be equipped with a safety switch or equivalent method to isolate...

  16. 30 CFR 75.1323 - Blasting circuits.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Blasting circuits. 75.1323 Section 75.1323... MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Explosives and Blasting § 75.1323 Blasting circuits. (a) Blasting circuits shall be protected from sources of stray electric current. (b) Detonators made...

  17. Symbols for communication circuit design and documentation

    NASA Astrophysics Data System (ADS)

    George, Michael; Pierson, Lyndon G.; Witzke, Edward L.

    A set of communication symbols has been developed at Sandia National Laboratories for designing and documenting communication circuits. The symbols can depict devices in a circuit, show proper interfacing of devices, and show the propagation of clocks, data, and control signals through the circuit. This paper defines the communication symbols and illustrates their usage.

  18. Performance optimization of digital VLSI circuits

    SciTech Connect

    Marple, D.P.

    1987-01-01

    Designers of digital VLSI circuits have virtually no computer tools available for the optimization of circuit performance. Instead, a designer relies extensively on circuit-analysis tools, such as circuit simulation (SPICE) and/or critical-delay-path analysis. A circuit-analysis approach to digital design is very labor-intensive and seldom produces a circuit with optimum area/delay or power/delay trade off. The goal of this research is to provide a synthesis approach to the design of digital circuits by finding the sizes of transistors that optimize circuits by finding the sizes of transistors that optimize circuit performance (delay, area, power). Solutions are found that are optimum for all possible delay paths of a given circuit and not for just a single path. The approach of this research is to formulate the problem of area/delay or power/delay optimization as a nonlinear program. Conditions for optimality are then established using graph theory and Kuhn-Tucker conditions. Finally, the use of augmented-Lagrangian and projected-Lagrangian algorithms are reviewed for the solution of the nonlinear programs. Two computer programs, PLATO and COP, were developed by the author to optimize CMOS PLA's (PLATO) and general CMOS circuits (COP). These tools provably find the globally optimum transistor sizes for a given circuit. Results are presented for PLA's and small- to medium-sized cells.

  19. 49 CFR 236.721 - Circuit, control.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Circuit, control. An electrical circuit between a source of electric energy and a device which it operates. ... 49 Transportation 4 2014-10-01 2014-10-01 false Circuit, control. 236.721 Section 236.721 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD...

  20. 49 CFR 236.726 - Circuit, track.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Circuit, track. An electrical circuit of which the rails of the track form a part. ... 49 Transportation 4 2012-10-01 2012-10-01 false Circuit, track. 236.726 Section 236.726 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD...

  1. 49 CFR 236.721 - Circuit, control.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Circuit, control. An electrical circuit between a source of electric energy and a device which it operates. ... 49 Transportation 4 2013-10-01 2013-10-01 false Circuit, control. 236.721 Section 236.721 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD...

  2. 49 CFR 236.721 - Circuit, control.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Circuit, control. An electrical circuit between a source of electric energy and a device which it operates. ... 49 Transportation 4 2012-10-01 2012-10-01 false Circuit, control. 236.721 Section 236.721 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD...

  3. 49 CFR 236.726 - Circuit, track.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Circuit, track. An electrical circuit of which the rails of the track form a part. ... 49 Transportation 4 2013-10-01 2013-10-01 false Circuit, track. 236.726 Section 236.726 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD...

  4. 49 CFR 236.726 - Circuit, track.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Circuit, track. An electrical circuit of which the rails of the track form a part. ... 49 Transportation 4 2014-10-01 2014-10-01 false Circuit, track. 236.726 Section 236.726 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD...

  5. 49 CFR 236.726 - Circuit, track.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Circuit, track. An electrical circuit of which the rails of the track form a part. ... 49 Transportation 4 2011-10-01 2011-10-01 false Circuit, track. 236.726 Section 236.726 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD...

  6. 49 CFR 236.721 - Circuit, control.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Circuit, control. An electrical circuit between a source of electric energy and a device which it operates. ... 49 Transportation 4 2011-10-01 2011-10-01 false Circuit, control. 236.721 Section 236.721 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD...

  7. 49 CFR 236.726 - Circuit, track.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Circuit, track. An electrical circuit of which the rails of the track form a part. ... 49 Transportation 4 2010-10-01 2010-10-01 false Circuit, track. 236.726 Section 236.726 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD...

  8. 49 CFR 234.203 - Control circuits.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Control circuits. 234.203 Section 234.203 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION..., Inspection, and Testing Maintenance Standards § 234.203 Control circuits. All control circuits that...

  9. LARC-SI Flatwire Twin Conduction Circuits

    NASA Technical Reports Server (NTRS)

    1995-01-01

    Eight 2-line, L-shaped gold flex circuits have been imprinted on 1-mil LARC-SI. Each circuit was embedded in a space-applications trapezoidal truss made of carbon fiber reinforced resin composite (with protruding ends) to facilitate electrical connection of electronic devices mounted on the truss. LARC-SI is an advanced polymer highly suitable for multi layered electrical circuits.

  10. 30 CFR 56.6407 - Circuit testing.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Circuit testing. 56.6407 Section 56.6407... Blasting § 56.6407 Circuit testing. A blasting galvanometer or other instrument designed for testing blasting circuits shall be used to test each of the following: (a) Continuity of each electric detonator...

  11. 30 CFR 57.6407 - Circuit testing.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Circuit testing. 57.6407 Section 57.6407... Blasting-Surface and Underground § 57.6407 Circuit testing. A blasting galvanometer or other instrument designed for testing blasting circuits shall be used to test the following: (a) In surface operations—...

  12. SiC JFET Transistor Circuit Model for Extreme Temperature Range

    NASA Technical Reports Server (NTRS)

    Neudeck, Philip G.

    2008-01-01

    A technique for simulating extreme-temperature operation of integrated circuits that incorporate silicon carbide (SiC) junction field-effect transistors (JFETs) has been developed. The technique involves modification of NGSPICE, which is an open-source version of the popular Simulation Program with Integrated Circuit Emphasis (SPICE) general-purpose analog-integrated-circuit-simulating software. NGSPICE in its unmodified form is used for simulating and designing circuits made from silicon-based transistors that operate at or near room temperature. Two rapid modifications of NGSPICE source code enable SiC JFETs to be simulated to 500 C using the well-known Level 1 model for silicon metal oxide semiconductor field-effect transistors (MOSFETs). First, the default value of the MOSFET surface potential must be changed. In the unmodified source code, this parameter has a value of 0.6, which corresponds to slightly more than half the bandgap of silicon. In NGSPICE modified to simulate SiC JFETs, this parameter is changed to a value of 1.6, corresponding to slightly more than half the bandgap of SiC. The second modification consists of changing the temperature dependence of MOSFET transconductance and saturation parameters. The unmodified NGSPICE source code implements a T(sup -1.5) temperature dependence for these parameters. In order to mimic the temperature behavior of experimental SiC JFETs, a T(sup -1.3) temperature dependence must be implemented in the NGSPICE source code. Following these two simple modifications, the Level 1 MOSFET model of the NGSPICE circuit simulation program reasonably approximates the measured high-temperature behavior of experimental SiC JFETs properly operated with zero or reverse bias applied to the gate terminal. Modification of additional silicon parameters in the NGSPICE source code was not necessary to model experimental SiC JFET current-voltage performance across the entire temperature range from 25 to 500 C.

  13. 30 CFR 75.601-1 - Short circuit protection; ratings and settings of circuit breakers.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Short circuit protection; ratings and settings of circuit breakers. 75.601-1 Section 75.601-1 Mineral Resources MINE SAFETY AND HEALTH... Trailing Cables § 75.601-1 Short circuit protection; ratings and settings of circuit breakers....

  14. Delay locked loop integrated circuit.

    SciTech Connect

    Brocato, Robert Wesley

    2007-10-01

    This report gives a description of the development of a Delay Locked Loop (DLL) integrated circuit (IC). The DLL was developed and tested as a stand-alone IC test chip to be integrated into a larger application specific integrated circuit (ASIC), the Quadrature Digital Waveform Synthesizer (QDWS). The purpose of the DLL is to provide a digitally programmable delay to enable synchronization between an internal system clock and external peripherals with unknown clock skew. The DLL was designed and fabricated in the IBM 8RF process, a 0.13 {micro}m CMOS process. It was designed to operate with a 300MHz clock and has been tested up to 500MHz.

  15. Delta connected resonant snubber circuit

    DOEpatents

    Lai, J.S.; Peng, F.Z.; Young, R.W. Sr.; Ott, G.W. Jr.

    1998-01-20

    A delta connected, resonant snubber-based, soft switching, inverter circuit achieves lossless switching during dc-to-ac power conversion and power conditioning with minimum component count and size. Current is supplied to the resonant snubber branches solely by the dc supply voltage through the main inverter switches and the auxiliary switches. Component count and size are reduced by use of a single semiconductor switch in the resonant snubber branches. Component count is also reduced by maximizing the use of stray capacitances of the main switches as parallel resonant capacitors. Resonance charging and discharging of the parallel capacitances allows lossless, zero voltage switching. In one embodiment, circuit component size and count are minimized while achieving lossless, zero voltage switching within a three-phase inverter. 36 figs.

  16. Delta connected resonant snubber circuit

    DOEpatents

    Lai, Jih-Sheng; Peng, Fang Zheng; Young, Sr., Robert W.; Ott, Jr., George W.

    1998-01-01

    A delta connected, resonant snubber-based, soft switching, inverter circuit achieves lossless switching during dc-to-ac power conversion and power conditioning with minimum component count and size. Current is supplied to the resonant snubber branches solely by the dc supply voltage through the main inverter switches and the auxiliary switches. Component count and size are reduced by use of a single semiconductor switch in the resonant snubber branches. Component count is also reduced by maximizing the use of stray capacitances of the main switches as parallel resonant capacitors. Resonance charging and discharging of the parallel capacitances allows lossless, zero voltage switching. In one embodiment, circuit component size and count are minimized while achieving lossless, zero voltage switching within a three-phase inverter.

  17. Crosstalk in QCA arithmetic circuits

    NASA Astrophysics Data System (ADS)

    Karim, Faizal; Walus, Konrad; Ivanov, André

    2006-08-01

    Quantum-Dot Cellular Automata (QCA) is one of several proposed computational nanotechnology paradigms that are being investigated as alternatives to CMOS at the nano-scale. QCA has been reported to offer relatively low power consumption, and very high device density. In recent years, several researchers have started investigating relatively complex circuit architectures using QCA. Such design efforts have highlighted the crosstalk problem in QCA and the lack of research in this area. This paper explores the nature of crosstalk in QCA. We show how crosstalk can be amplified due to several parameters including wire length and the distance between adjacent cells. We develop a model and method that allows us to test for crosstalk using a set of test vectors. We also propose a set of cell placement guidelines and design geometries that help to minimize QCA crosstalk in large circuits.

  18. Handbook of microwave integrated circuits

    NASA Astrophysics Data System (ADS)

    Hoffmann, Reinmut K.

    The design and operation of ICs for use in the 0.5-20-GHz range are described in an introductory and reference work for industrial engineers. Chapters are devoted to an overview of microwave IC (MIC) technology, general stripline characteristics, microwave transmission line (MTL) parameters for microstrips with isotropic dielectric substrates, higher-order modes on a microstrip, the effects of metallic enclosure on MTL transmission parameters, losses in microstrips, the measurement of MTL parameters, and MTLs on anisotropic dielectric substrates. Consideration is given to coupled microstrips on dielectric substrates, microstrip discontinuities, radiation from microstrip circuits, MTL variations, coplanar MTLs, slotlines, and spurious modes in MTL circuits. Diagrams, drawings, graphs, and a glossary of symbols are provided.

  19. Phonon waveguides for electromechanical circuits.

    PubMed

    Hatanaka, D; Mahboob, I; Onomitsu, K; Yamaguchi, H

    2014-07-01

    Nanoelectromechanical systems (NEMS), utilizing localized mechanical vibrations, have found application in sensors, signal processors and in the study of macroscopic quantum mechanics. The integration of multiple mechanical elements via electrical or optical means remains a challenge in the realization of NEMS circuits. Here, we develop a phonon waveguide using a one-dimensional array of suspended membranes that offers purely mechanical means to integrate isolated NEMS resonators. We demonstrate that the phonon waveguide can support and guide mechanical vibrations and that the periodic membrane arrangement also creates a phonon bandgap that enables control of the phonon propagation velocity. Furthermore, embedding a phonon cavity into the phonon waveguide allows mobile mechanical vibrations to be dynamically switched or transferred from the waveguide to the cavity, thereby illustrating the viability of waveguide-resonator coupling. These highly functional traits of the phonon waveguide architecture exhibit all the components necessary to permit the realization of all-phononic NEMS circuits.

  20. Ionization tube simmer current circuit

    DOEpatents

    Steinkraus, R.F. Jr.

    1994-12-13

    A highly efficient flash lamp simmer current circuit utilizes a fifty percent duty cycle square wave pulse generator to pass a current over a current limiting inductor to a full wave rectifier. The DC output of the rectifier is then passed over a voltage smoothing capacitor through a reverse current blocking diode to a flash lamp tube to sustain ionization in the tube between discharges via a small simmer current. An alternate embodiment of the circuit combines the pulse generator and inductor in the form of an FET off line square wave generator with an impedance limited step up output transformer which is then applied to the full wave rectifier as before to yield a similar simmer current. 6 figures.

  1. Ionization tube simmer current circuit

    DOEpatents

    Steinkraus, Jr., Robert F.

    1994-01-01

    A highly efficient flash lamp simmer current circuit utilizes a fifty percent duty cycle square wave pulse generator to pass a current over a current limiting inductor to a full wave rectifier. The DC output of the rectifier is then passed over a voltage smoothing capacitor through a reverse current blocking diode to a flash lamp tube to sustain ionization in the tube between discharges via a small simmer current. An alternate embodiment of the circuit combines the pulse generator and inductor in the form of an FET off line square wave generator with an impedance limited step up output transformer which is then applied to the full wave rectifier as before to yield a similar simmer current.

  2. Pyramid image codes

    NASA Technical Reports Server (NTRS)

    Watson, Andrew B.

    1990-01-01

    All vision systems, both human and machine, transform the spatial image into a coded representation. Particular codes may be optimized for efficiency or to extract useful image features. Researchers explored image codes based on primary visual cortex in man and other primates. Understanding these codes will advance the art in image coding, autonomous vision, and computational human factors. In cortex, imagery is coded by features that vary in size, orientation, and position. Researchers have devised a mathematical model of this transformation, called the Hexagonal oriented Orthogonal quadrature Pyramid (HOP). In a pyramid code, features are segregated by size into layers, with fewer features in the layers devoted to large features. Pyramid schemes provide scale invariance, and are useful for coarse-to-fine searching and for progressive transmission of images. The HOP Pyramid is novel in three respects: (1) it uses a hexagonal pixel lattice, (2) it uses oriented features, and (3) it accurately models most of the prominent aspects of primary visual cortex. The transform uses seven basic features (kernels), which may be regarded as three oriented edges, three oriented bars, and one non-oriented blob. Application of these kernels to non-overlapping seven-pixel neighborhoods yields six oriented, high-pass pyramid layers, and one low-pass (blob) layer.

  3. Report number codes

    SciTech Connect

    Nelson, R.N.

    1985-05-01

    This publication lists all report number codes processed by the Office of Scientific and Technical Information. The report codes are substantially based on the American National Standards Institute, Standard Technical Report Number (STRN)-Format and Creation Z39.23-1983. The Standard Technical Report Number (STRN) provides one of the primary methods of identifying a specific technical report. The STRN consists of two parts: The report code and the sequential number. The report code identifies the issuing organization, a specific program, or a type of document. The sequential number, which is assigned in sequence by each report issuing entity, is not included in this publication. Part I of this compilation is alphabetized by report codes followed by issuing installations. Part II lists the issuing organization followed by the assigned report code(s). In both Parts I and II, the names of issuing organizations appear for the most part in the form used at the time the reports were issued. However, for some of the more prolific installations which have had name changes, all entries have been merged under the current name.

  4. Embedded foveation image coding.

    PubMed

    Wang, Z; Bovik, A C

    2001-01-01

    The human visual system (HVS) is highly space-variant in sampling, coding, processing, and understanding. The spatial resolution of the HVS is highest around the point of fixation (foveation point) and decreases rapidly with increasing eccentricity. By taking advantage of this fact, it is possible to remove considerable high-frequency information redundancy from the peripheral regions and still reconstruct a perceptually good quality image. Great success has been obtained previously by a class of embedded wavelet image coding algorithms, such as the embedded zerotree wavelet (EZW) and the set partitioning in hierarchical trees (SPIHT) algorithms. Embedded wavelet coding not only provides very good compression performance, but also has the property that the bitstream can be truncated at any point and still be decoded to recreate a reasonably good quality image. In this paper, we propose an embedded foveation image coding (EFIC) algorithm, which orders the encoded bitstream to optimize foveated visual quality at arbitrary bit-rates. A foveation-based image quality metric, namely, foveated wavelet image quality index (FWQI), plays an important role in the EFIC system. We also developed a modified SPIHT algorithm to improve the coding efficiency. Experiments show that EFIC integrates foveation filtering with foveated image coding and demonstrates very good coding performance and scalability in terms of foveated image quality measurement.

  5. Monolithic readout circuits for RHIC

    SciTech Connect

    O`Connor, P.; Harder, J.

    1991-12-31

    Several CMOS ASICs have been developed for a proposed RHIC experiment. This paper discusses why ASIC implementation was chosen for certain functions, circuit specifications and the design techniques used to meet them, and results of simulations and early prototypes. By working closely together from an early stage in the planning process, in-house ASIC designers and detector and data acquisition experimenters can achieve optimal use of this important technology.

  6. On being a circuit psychiatrist.

    PubMed

    Gordon, Joshua A

    2016-10-26

    At this unique and exciting time for psychiatry, novel therapies for individuals with mental illnesses seem just around the corner. In particular, recent technological advancements in the study of neural circuits provide reasons to be optimistic that the field is headed in the right direction. Nonetheless, maximizing the chances of translating these advancements into real improvements in patient care requires a carefully considered road map.

  7. Counterpulse railgun energy recovery circuit

    DOEpatents

    Honig, Emanuel M.

    1986-01-01

    In an electromagnetic launcher such as a railgun for propelling a projectile at high velocity, a counterpulse energy recovery circuit is employed to transfer stored inductive energy from a source inductor to the railgun inductance to propel the projectile down the railgun. Switching circuitry and an energy transfer capacitor are used to switch the energy back to the source inductor in readiness for a repetitive projectile propelling cycle.

  8. Overpulse railgun energy recovery circuit

    DOEpatents

    Honig, Emanuel M.

    1989-01-01

    In an electromagnetic launcher such as a railgun for propelling a projectile at high velocity, an overpulse energy recovery circuit is employed to transfer stored inductive energy from a source inductor to the railgun inductance to propel the projectile down the railgun. Switching circuitry and an energy transfer capacitor are used to switch the energy back to the source inductor in readiness for a repetitive projectile propelling cycle.

  9. Pulse Circuits of Radar Stations

    DTIC Science & Technology

    1982-08-06

    SUPERVISION (Recommendation for the Teacher ) Effective use of the book in an auditorium under the supervision of a teacher and the latter’s participation...work independently, students voluntari. y outline the material in . their notebooks and can approach the teacher with an,, questions (for example, on...cirves, circuits) and provide them to the teacher for a critique. The teacher examines the answer and, depending on the degree of its correctness and

  10. Electrical circuit for data reduction

    SciTech Connect

    Kronberg, J.W.

    1991-12-31

    This invention is comprised of an electrical circuit for determining characteristic voltages, such as maximum, minimum, average and root mean squared voltages, of a time-varying electrical signal. The circuit comprises a positive and a negative peak detector that feed the positive and negative voltage peaks detected in each of a series of time intervals into a solid-state multiplexer controlled by a process controller. The time intervals are generated by the process controller in combination with a clocking, circuit. The multiplexer applies the positive and negative peak voltages to a set of four capacitors, apply the positive peak to one capacitor during one interval and then the negative peak to that capacitor in a subsequent interval so that each capacitor is alternatingly accumulating a positive peak then a negative peak to obviate the need for resetting each capacitor. After the positive peak voltage is applied to one capacitor, the connection is switched during the next interval for reading the negative peak voltage, then switched again for applying, a negative peak voltage, then switched once more for reading the negative peak voltage, the multiplexer serving, as a solid state commutator for switching the electrical connection. Alternatively, peak maximum and minimum voltage detectors may be replaced with circuitry designed to obtain the additional characteristic voltages desired in each interval.

  11. CONTROL AND FAULT DETECTOR CIRCUIT

    DOEpatents

    Winningstad, C.N.

    1958-04-01

    A power control and fault detectcr circuit for a radiofrequency system is described. The operation of the circuit controls the power output of a radio- frequency power supply to automatically start the flow of energizing power to the radio-frequency power supply and to gradually increase the power to a predetermined level which is below the point where destruction occurs upon the happening of a fault. If the radio-frequency power supply output fails to increase during such period, the control does not further increase the power. On the other hand, if the output of the radio-frequency power supply properly increases, then the control continues to increase the power to a maximum value. After the maximumn value of radio-frequency output has been achieved. the control is responsive to a ''fault,'' such as a short circuit in the radio-frequency system being driven, so that the flow of power is interrupted for an interval before the cycle is repeated.

  12. Additive manufacturing of hybrid circuits

    DOE PAGES

    Bell, Nelson S.; Sarobol, Pylin; Cook, Adam; ...

    2016-03-26

    There is a rising interest in developing functional electronics using additively manufactured components. Considerations in materials selection and pathways to forming hybrid circuits and devices must demonstrate useful electronic function; must enable integration; and must complement the complex shape, low cost, high volume, and high functionality of structural but generally electronically passive additively manufactured components. This article reviews several emerging technologies being used in industry and research/development to provide integration advantages of fabricating multilayer hybrid circuits or devices. First, we review a maskless, noncontact, direct write (DW) technology that excels in the deposition of metallic colloid inks for electrical interconnects.more » Second, we review a complementary technology, aerosol deposition (AD), which excels in the deposition of metallic and ceramic powder as consolidated, thick conformal coatings and is additionally patternable through masking. As a result, we show examples of hybrid circuits/devices integrated beyond 2-D planes, using combinations of DW or AD processes and conventional, established processes.« less

  13. Integrated acoustooptic circuits and applications.

    PubMed

    Tsai, C S

    1992-01-01

    The recent development of titanium-indiffusion proton-exchange (TIPE) microlenses and lens arrays has made possible the construction of a variety of single- and multichannel integrated acoustooptic (AO) and acoustooptic-electrooptic (EO) circuits in LiNbO(3) channel-planar waveguides 0.1x1.0x2.0 cm(3) in size. These hybrid AO and AO-EO circuits can be fabricated through compatible and well-established technologies. The most recent realization of ion-milled microlenses and lens arrays together with the recent development of gigahertz AO Bragg modulators and EO Bragg modulator arrays have also paved the way for construction of similar but monolithic AO and AO-EO GaAs/GaAlAs waveguides of comparable size. Both types of integrated AO and AO-EO circuits suggest versatile applications in communications signal processing, and computing. Efficient and simultaneous excitation of the channel waveguide array using an ion-milled planar microlens array has facilitated the demonstration of some of these applications.

  14. Addressing biological uncertainties in engineering gene circuits.

    PubMed

    Zhang, Carolyn; Tsoi, Ryan; You, Lingchong

    2016-04-18

    Synthetic biology has grown tremendously over the past fifteen years. It represents a new strategy to develop biological understanding and holds great promise for diverse practical applications. Engineering of a gene circuit typically involves computational design of the circuit, selection of circuit components, and test and optimization of circuit functions. A fundamental challenge in this process is the predictable control of circuit function due to multiple layers of biological uncertainties. These uncertainties can arise from different sources. We categorize these uncertainties into incomplete quantification of parts, interactions between heterologous components and the host, or stochastic dynamics of chemical reactions and outline potential design strategies to minimize or exploit them.

  15. 46 CFR 28.860 - Overcurrent protection and switched circuits.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... steering circuit, each circuit must be protected against both overload and short circuit. Each overcurrent device in a steering system power and control circuit must provide protection only. (c) Each...

  16. 46 CFR 28.860 - Overcurrent protection and switched circuits.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... steering circuit, each circuit must be protected against both overload and short circuit. Each overcurrent device in a steering system power and control circuit must provide protection only. (c) Each...

  17. 46 CFR 28.860 - Overcurrent protection and switched circuits.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... steering circuit, each circuit must be protected against both overload and short circuit. Each overcurrent device in a steering system power and control circuit must provide protection only. (c) Each...

  18. 46 CFR 28.860 - Overcurrent protection and switched circuits.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... steering circuit, each circuit must be protected against both overload and short circuit. Each overcurrent device in a steering system power and control circuit must provide protection only. (c) Each...

  19. 46 CFR 28.860 - Overcurrent protection and switched circuits.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... steering circuit, each circuit must be protected against both overload and short circuit. Each overcurrent device in a steering system power and control circuit must provide protection only. (c) Each...

  20. Status and Benchmarking of the Free Boundary Equilibrium Code FREEBIE

    NASA Astrophysics Data System (ADS)

    Urban, Jakub; Artaud, Jean-Francois; Basiuk, Vincent; Besseghir, Karim; Huynh, Philippe; Kim, Sunhee; Lister, Jonathan Bryan; Nardon, Eric

    2013-10-01

    FREEBIE is a recent free boundary equilibrium (FBE) code, which solves the temporal evolution of tokamak equilibrium, described by the Grad-Shafranov equation and circuit equations for active and passive poloidal field components. FREEBIE can be run stand-alone, within the transport code CRONOS or on the ITM (European Integrated Tokamak Modelling) platform. FREEBIE with prescribed plasma profiles has already been successfully benchmarked against DINA simulations and TCV experiments. Here we report on the current status of the code coupling with transport solvers and benchmarking of fully consistent transport-FBE simulations. A benchmarking procedure is developed and applied to several ITER cases using FREEBIE, DINA and CEDRES++. The benchmarks indicate that because of the different methods and the complexity of the problem, results obtained from the different codes are comparable only to a certain extent. Supported by GACR 13-38121P, EURATOM, AS CR AV0Z 20430508, MSMT 7G10072 and MSMT LM2011021.

  1. RBMK-LOCA-Analyses with the ATHLET-Code

    SciTech Connect

    Petry, A.; Domoradov, A.; Finjakin, A.

    1995-09-01

    The scientific technical cooperation between Germany and Russia includes the area of adaptation of several German codes for the Russian-designed RBMK-reactor. One point of this cooperation is the adaptation of the Thermal-Hydraulic code ATHLET (Analyses of the Thermal-Hydraulics of LEaks and Transients), for RBMK-specific safety problems. This paper contains a short description of a RBMK-1000 reactor circuit. Furthermore, the main features of the thermal-hydraulic code ATHLET are presented. The main assumptions for the ATHLET-RBMK model are discussed. As an example for the application, the results of test calculations concerning a guillotine type rupture of a distribution group header are presented and discussed, and the general analysis conditions are described. A comparison with corresponding RELAP-calculations is given. This paper gives an overview on some problems posed and experience by application of Western best-estimate codes for RBMK-calculations.

  2. Method and Circuit for Injecting a Precise Amount of Charge onto a Circuit Node

    NASA Technical Reports Server (NTRS)

    Hancock, Bruce R. (Inventor)

    2016-01-01

    A method and circuit for injecting charge into a circuit node, comprising (a) resetting a capacitor's voltage through a first transistor; (b) after the resetting, pre-charging the capacitor through the first transistor; and (c) after the pre-charging, further charging the capacitor through a second transistor, wherein the second transistor is connected between the capacitor and a circuit node, and the further charging draws charge through the second transistor from the circuit node, thereby injecting charge into the circuit node.

  3. Method of determining the open circuit voltage of a battery in a closed circuit

    DOEpatents

    Brown, William E.

    1980-01-01

    The open circuit voltage of a battery which is connected in a closed circuit is determined without breaking the circuit or causing voltage upsets therein. The closed circuit voltage across the battery and the current flowing through it are determined under normal load and then a fractional change is made in the load and the new current and voltage values determined. The open circuit voltage is then calculated, according to known principles, from the two sets of values.

  4. The Development of a Portable Hard Disk Encryption/Decryption System with a MEMS Coded Lock.

    PubMed

    Zhang, Weiping; Chen, Wenyuan; Tang, Jian; Xu, Peng; Li, Yibin; Li, Shengyong

    2009-01-01

    In this paper, a novel portable hard-disk encryption/decryption system with a MEMS coded lock is presented, which can authenticate the user and provide the key for the AES encryption/decryption module. The portable hard-disk encryption/decryption system is composed of the authentication module, the USB portable hard-disk interface card, the ATA protocol command decoder module, the data encryption/decryption module, the cipher key management module, the MEMS coded lock controlling circuit module, the MEMS coded lock and the hard disk. The ATA protocol circuit, the MEMS control circuit and AES encryption/decryption circuit are designed and realized by FPGA(Field Programmable Gate Array). The MEMS coded lock with two couplers and two groups of counter-meshing-gears (CMGs) are fabricated by a LIGA-like process and precision engineering method. The whole prototype was fabricated and tested. The test results show that the user's password could be correctly discriminated by the MEMS coded lock, and the AES encryption module could get the key from the MEMS coded lock. Moreover, the data in the hard-disk could be encrypted or decrypted, and the read-write speed of the dataflow could reach 17 MB/s in Ultra DMA mode.

  5. Multiplexed temporal coding of electric communication signals in mormyrid fishes

    PubMed Central

    Baker, Christa A.; Kohashi, Tsunehiko; Lyons-Warren, Ariel M.; Ma, Xiaofeng; Carlson, Bruce A.

    2013-01-01

    Summary The coding of stimulus information into patterns of spike times occurs widely in sensory systems. Determining how temporally coded information is decoded by central neurons is essential to understanding how brains process sensory stimuli. Mormyrid weakly electric fishes are experts at time coding, making them an exemplary organism for addressing this question. Mormyrids generate brief, stereotyped electric pulses. Pulse waveform carries information about sender identity, and it is encoded into submillisecond-to-millisecond differences in spike timing between receptors. Mormyrids vary the time between pulses to communicate behavioral state, and these intervals are encoded into the sequence of interspike intervals within receptors. Thus, the responses of peripheral electroreceptors establish a temporally multiplexed code for communication signals, one consisting of spike timing differences between receptors and a second consisting of interspike intervals within receptors. These signals are processed in a dedicated sensory pathway, and recent studies have shed light on the mechanisms by which central circuits can extract behaviorally relevant information from multiplexed temporal codes. Evolutionary change in the anatomy of this pathway is related to differences in electrosensory perception, which appears to have influenced the diversification of electric signals and species. However, it remains unknown how this evolutionary change relates to differences in sensory coding schemes, neuronal circuitry and central sensory processing. The mormyrid electric communication pathway is a powerful model for integrating mechanistic studies of temporal coding with evolutionary studies of correlated differences in brain and behavior to investigate neural mechanisms for processing temporal codes. PMID:23761462

  6. Hamming and Accumulator Codes Concatenated with MPSK or QAM

    NASA Technical Reports Server (NTRS)

    Divsalar, Dariush; Dolinar, Samuel

    2009-01-01

    In a proposed coding-and-modulation scheme, a high-rate binary data stream would be processed as follows: 1. The input bit stream would be demultiplexed into multiple bit streams. 2. The multiple bit streams would be processed simultaneously into a high-rate outer Hamming code that would comprise multiple short constituent Hamming codes a distinct constituent Hamming code for each stream. 3. The streams would be interleaved. The interleaver would have a block structure that would facilitate parallelization for high-speed decoding. 4. The interleaved streams would be further processed simultaneously into an inner two-state, rate-1 accumulator code that would comprise multiple constituent accumulator codes - a distinct accumulator code for each stream. 5. The resulting bit streams would be mapped into symbols to be transmitted by use of a higher-order modulation - for example, M-ary phase-shift keying (MPSK) or quadrature amplitude modulation (QAM). The novelty of the scheme lies in the concatenation of the multiple-constituent Hamming and accumulator codes and the corresponding parallel architectures of the encoder and decoder circuitry (see figure) needed to process the multiple bit streams simultaneously. As in the cases of other parallel-processing schemes, one advantage of this scheme is that the overall data rate could be much greater than the data rate of each encoder and decoder stream and, hence, the encoder and decoder could handle data at an overall rate beyond the capability of the individual encoder and decoder circuits.

  7. Multiplexed temporal coding of electric communication signals in mormyrid fishes.

    PubMed

    Baker, Christa A; Kohashi, Tsunehiko; Lyons-Warren, Ariel M; Ma, Xiaofeng; Carlson, Bruce A

    2013-07-01

    The coding of stimulus information into patterns of spike times occurs widely in sensory systems. Determining how temporally coded information is decoded by central neurons is essential to understanding how brains process sensory stimuli. Mormyrid weakly electric fishes are experts at time coding, making them an exemplary organism for addressing this question. Mormyrids generate brief, stereotyped electric pulses. Pulse waveform carries information about sender identity, and it is encoded into submillisecond-to-millisecond differences in spike timing between receptors. Mormyrids vary the time between pulses to communicate behavioral state, and these intervals are encoded into the sequence of interspike intervals within receptors. Thus, the responses of peripheral electroreceptors establish a temporally multiplexed code for communication signals, one consisting of spike timing differences between receptors and a second consisting of interspike intervals within receptors. These signals are processed in a dedicated sensory pathway, and recent studies have shed light on the mechanisms by which central circuits can extract behaviorally relevant information from multiplexed temporal codes. Evolutionary change in the anatomy of this pathway is related to differences in electrosensory perception, which appears to have influenced the diversification of electric signals and species. However, it remains unknown how this evolutionary change relates to differences in sensory coding schemes, neuronal circuitry and central sensory processing. The mormyrid electric communication pathway is a powerful model for integrating mechanistic studies of temporal coding with evolutionary studies of correlated differences in brain and behavior to investigate neural mechanisms for processing temporal codes.

  8. Adaptive neural coding: from biological to behavioral decision-making

    PubMed Central

    Louie, Kenway; Glimcher, Paul W.; Webb, Ryan

    2015-01-01

    Empirical decision-making in diverse species deviates from the predictions of normative choice theory, but why such suboptimal behavior occurs is unknown. Here, we propose that deviations from optimality arise from biological decision mechanisms that have evolved to maximize choice performance within intrinsic biophysical constraints. Sensory processing utilizes specific computations such as divisive normalization to maximize information coding in constrained neural circuits, and recent evidence suggests that analogous computations operate in decision-related brain areas. These adaptive computations implement a relative value code that may explain the characteristic context-dependent nature of behavioral violations of classical normative theory. Examining decision-making at the computational level thus provides a crucial link between the architecture of biological decision circuits and the form of empirical choice behavior. PMID:26722666

  9. Code Disentanglement: Initial Plan

    SciTech Connect

    Wohlbier, John Greaton; Kelley, Timothy M.; Rockefeller, Gabriel M.; Calef, Matthew Thomas

    2015-01-27

    The first step to making more ambitious changes in the EAP code base is to disentangle the code into a set of independent, levelized packages. We define a package as a collection of code, most often across a set of files, that provides a defined set of functionality; a package a) can be built and tested as an entity and b) fits within an overall levelization design. Each package contributes one or more libraries, or an application that uses the other libraries. A package set is levelized if the relationships between packages form a directed, acyclic graph and each package uses only packages at lower levels of the diagram (in Fortran this relationship is often describable by the use relationship between modules). Independent packages permit independent- and therefore parallel|development. The packages form separable units for the purposes of development and testing. This is a proven path for enabling finer-grained changes to a complex code.

  10. Compressible Astrophysics Simulation Code

    SciTech Connect

    Howell, L.; Singer, M.

    2007-07-18

    This is an astrophysics simulation code involving a radiation diffusion module developed at LLNL coupled to compressible hydrodynamics and adaptive mesh infrastructure developed at LBNL. One intended application is to neutrino diffusion in core collapse supernovae.

  11. Graphene radio frequency receiver integrated circuit.

    PubMed

    Han, Shu-Jen; Garcia, Alberto Valdes; Oida, Satoshi; Jenkins, Keith A; Haensch, Wilfried

    2014-01-01

    Graphene has attracted much interest as a future channel material in radio frequency electronics because of its superior electrical properties. Fabrication of a graphene integrated circuit without significantly degrading transistor performance has proven to be challenging, posing one of the major bottlenecks to compete with existing technologies. Here we present a fabrication method fully preserving graphene transistor quality, demonstrated with the implementation of a high-performance three-stage graphene integrated circuit. The circuit operates as a radio frequency receiver performing signal amplification, filtering and downconversion mixing. All circuit components are integrated into 0.6 mm(2) area and fabricated on 200 mm silicon wafers, showing the unprecedented graphene circuit complexity and silicon complementary metal-oxide-semiconductor process compatibility. The demonstrated circuit performance allow us to use graphene integrated circuit to perform practical wireless communication functions, receiving and restoring digital text transmitted on a 4.3-GHz carrier signal.

  12. Auto-programmable impulse neural circuits

    NASA Technical Reports Server (NTRS)

    Watula, D.; Meador, J.

    1990-01-01

    Impulse neural networks use pulse trains to communicate neuron activation levels. Impulse neural circuits emulate natural neurons at a more detailed level than that typically employed by contemporary neural network implementation methods. An impulse neural circuit which realizes short term memory dynamics is presented. The operation of that circuit is then characterized in terms of pulse frequency modulated signals. Both fixed and programmable synapse circuits for realizing long term memory are also described. The implementation of a simple and useful unsupervised learning law is then presented. The implementation of a differential Hebbian learning rule for a specific mean-frequency signal interpretation is shown to have a straightforward implementation using digital combinational logic with a variation of a previously developed programmable synapse circuit. This circuit is expected to be exploited for simple and straightforward implementation of future auto-adaptive neural circuits.

  13. Standardized communication symbols to facilitate circuit design

    NASA Astrophysics Data System (ADS)

    George, M.; Pierson, L. G.

    1990-05-01

    In the course of communication circuit design at Sandia National Laboratories, a set of communication symbols was created to aid, and hopefully standardize, the design process. These symbols, which allow the designer to build a circuit using black boxes, simplify circuit design and documentation. They also provide a standard set to help minimize interpretation problems among circuit designers. The symbols can be used to represent various devices in a circuit, such as modems, computers, terminals, encryption devices, converters, etc. When using these symbols to design communication circuits, the contours of each symbol show which devices interface together. Mismatch device contours indicate the need for another element (such as a null modem) between the two devices. In addition, the propagation of clock, data, and control signals through the circuit can be represented. Clocking modes on synchronous components (modems, multiplexers, etc.) and signal line crossovers can also be determined from the drawings during the design process.

  14. More About Vector Adaptive/Predictive Coding Of Speech

    NASA Technical Reports Server (NTRS)

    Jedrey, Thomas C.; Gersho, Allen

    1992-01-01

    Report presents additional information about digital speech-encoding and -decoding system described in "Vector Adaptive/Predictive Encoding of Speech" (NPO-17230). Summarizes development of vector adaptive/predictive coding (VAPC) system and describes basic functions of algorithm. Describes refinements introduced enabling receiver to cope with errors. VAPC algorithm implemented in integrated-circuit coding/decoding processors (codecs). VAPC and other codecs tested under variety of operating conditions. Tests designed to reveal effects of various background quiet and noisy environments and of poor telephone equipment. VAPC found competitive with and, in some respects, superior to other 4.8-kb/s codecs and other codecs of similar complexity.

  15. Seals Flow Code Development

    NASA Technical Reports Server (NTRS)

    1991-01-01

    In recognition of a deficiency in the current modeling capability for seals, an effort was established by NASA to develop verified computational fluid dynamic concepts, codes, and analyses for seals. The objectives were to develop advanced concepts for the design and analysis of seals, to effectively disseminate the information to potential users by way of annual workshops, and to provide experimental verification for the models and codes under a wide range of operating conditions.

  16. Robust Nonlinear Neural Codes

    NASA Astrophysics Data System (ADS)

    Yang, Qianli; Pitkow, Xaq

    2015-03-01

    Most interesting natural sensory stimuli are encoded in the brain in a form that can only be decoded nonlinearly. But despite being a core function of the brain, nonlinear population codes are rarely studied and poorly understood. Interestingly, the few existing models of nonlinear codes are inconsistent with known architectural features of the brain. In particular, these codes have information content that scales with the size of the cortical population, even if that violates the data processing inequality by exceeding the amount of information entering the sensory system. Here we provide a valid theory of nonlinear population codes by generalizing recent work on information-limiting correlations in linear population codes. Although these generalized, nonlinear information-limiting correlations bound the performance of any decoder, they also make decoding more robust to suboptimal computation, allowing many suboptimal decoders to achieve nearly the same efficiency as an optimal decoder. Although these correlations are extremely difficult to measure directly, particularly for nonlinear codes, we provide a simple, practical test by which one can use choice-related activity in small populations of neurons to determine whether decoding is suboptimal or optimal and limited by correlated noise. We conclude by describing an example computation in the vestibular system where this theory applies. QY and XP was supported by a grant from the McNair foundation.

  17. Dynamic Flux Tubes Form Reservoirs of Stability in Neuronal Circuits

    NASA Astrophysics Data System (ADS)

    Monteforte, Michael; Wolf, Fred

    2012-10-01

    Neurons in cerebral cortical circuits interact by sending and receiving electrical impulses called spikes. The ongoing spiking activity of cortical circuits is fundamental to many cognitive functions including sensory processing, working memory, and decision making. London et al. [Sensitivity to Perturbations In Vivo Implies High Noise and Suggests Rate Coding in Cortex, Nature (London)NATUAS0028-0836 466, 123 (2010).10.1038/nature09086] recently argued that even a single additional spike can cause a cascade of extra spikes that rapidly decorrelate the microstate of the network. Here, we show theoretically in a minimal model of cortical neuronal circuits that single-spike perturbations trigger only a very weak rate response. Nevertheless, single-spike perturbations are found to rapidly decorrelate the microstate of the network, although the dynamics is stable with respect to small perturbations. The coexistence of stable and unstable dynamics results from a system of exponentially separating dynamic flux tubes around stable trajectories in the network’s phase space. The radius of these flux tubes appears to decrease algebraically with neuron number N and connectivity K, which implies that the entropy of the circuit’s repertoire of state sequences scales as Nln⁡(KN).

  18. Exact Magnetic Diffusion Solutions for Magnetohydrodynamic Code Verification

    SciTech Connect

    Miller, D S

    2010-12-03

    In this paper, the authors present several new exact analytic space and time dependent solutions to the problem of magnetic diffusion in R-Z geometry. These problems serve to verify several different elements of an MHD implementation: magnetic diffusion, external circuit time integration, current and voltage energy sources, spatially dependent conductivities, and ohmic heating. The exact solutions are shown in comparison with 2D simulation results from the Ares code.

  19. Analyzing Pulse-Code Modulation On A Small Computer

    NASA Technical Reports Server (NTRS)

    Massey, David E.

    1988-01-01

    System for analysis pulse-code modulation (PCM) comprises personal computer, computer program, and peripheral interface adapter on circuit board that plugs into expansion bus of computer. Functions essentially as "snapshot" PCM decommutator, which accepts and stores thousands of frames of PCM data, sifts through them repeatedly to process according to routines specified by operator. Enables faster testing and involves less equipment than older testing systems.

  20. The neural circuit basis of learning

    NASA Astrophysics Data System (ADS)

    Patrick, Kaifosh William John

    The astounding capacity for learning ranks among the nervous system's most impressive features. This thesis comprises studies employing varied approaches to improve understanding, at the level of neural circuits, of the brain's capacity for learning. The first part of the thesis contains investigations of hippocampal circuitry -- both theoretical work and experimental work in the mouse Mus musculus -- as a model system for declarative memory. To begin, Chapter 2 presents a theory of hippocampal memory storage and retrieval that reflects nonlinear dendritic processing within hippocampal pyramidal neurons. As a prelude to the experimental work that comprises the remainder of this part, Chapter 3 describes an open source software platform that we have developed for analysis of data acquired with in vivo Ca2+ imaging, the main experimental technique used throughout the remainder of this part of the thesis. As a first application of this technique, Chapter 4 characterizes the content of signaling at synapses between GABAergic neurons of the medial septum and interneurons in stratum oriens of hippocampal area CA1. Chapter 5 then combines these techniques with optogenetic, pharmacogenetic, and pharmacological manipulations to uncover inhibitory circuit mechanisms underlying fear learning. The second part of this thesis focuses on the cerebellum-like electrosensory lobe in the weakly electric mormyrid fish Gnathonemus petersii, as a model system for non-declarative memory. In Chapter 6, we study how short-duration EOD motor commands are recoded into a complex temporal basis in the granule cell layer, which can be used to cancel Purkinje-like cell firing to the longer duration and temporally varying EOD-driven sensory responses. In Chapter 7, we consider not only the temporal aspects of the granule cell code, but also the encoding of body position provided from proprioceptive and efference copy sources. Together these studies clarify how the cerebellum-like circuitry of the

  1. Recursive Optimization of Digital Circuits

    DTIC Science & Technology

    1990-12-14

    Circuit Implementation of f(x, y, z) = xyi ’ + zz ................... 3-6 3.2. Karnaugh Map for xy’z + xyz + cy’ = zy + zz .............. .... 3-7 3.3. A...use of non-deterministic search processes such as the use of genetic algorithms (47). Genetic algorithms are an adaptive search process that has...September, 1984). 47. Goldberg, D.E. Genetic Algorithms in Search and Machine Learning. Reading, MA: Addison-Welsey, 1989. 48. Gore, Rajeev P. and Kotagiri

  2. Quantum Memristors with Superconducting Circuits

    PubMed Central

    Salmilehto, J.; Deppe, F.; Di Ventra, M.; Sanz, M.; Solano, E.

    2017-01-01

    Memristors are resistive elements retaining information of their past dynamics. They have garnered substantial interest due to their potential for representing a paradigm change in electronics, information processing and unconventional computing. Given the advent of quantum technologies, a design for a quantum memristor with superconducting circuits may be envisaged. Along these lines, we introduce such a quantum device whose memristive behavior arises from quasiparticle-induced tunneling when supercurrents are cancelled. For realistic parameters, we find that the relevant hysteretic behavior may be observed using current state-of-the-art measurements of the phase-driven tunneling current. Finally, we develop suitable methods to quantify memory retention in the system. PMID:28195193

  3. Circuit for Driving Piezoelectric Transducers

    NASA Technical Reports Server (NTRS)

    Randall, David P.; Chapsky, Jacob

    2009-01-01

    The figure schematically depicts an oscillator circuit for driving a piezoelectric transducer to excite vibrations in a mechanical structure. The circuit was designed and built to satisfy application-specific requirements to drive a selected one of 16 such transducers at a regulated amplitude and frequency chosen to optimize the amount of work performed by the transducer and to compensate for both (1) temporal variations of the resonance frequency and damping time of each transducer and (2) initially unknown differences among the resonance frequencies and damping times of different transducers. In other words, the circuit is designed to adjust itself to optimize the performance of whichever transducer is selected at any given time. The basic design concept may be adaptable to other applications that involve the use of piezoelectric transducers in ultrasonic cleaners and other apparatuses in which high-frequency mechanical drives are utilized. This circuit includes three resistor-capacitor networks that, together with the selected piezoelectric transducer, constitute a band-pass filter having a peak response at a frequency of about 2 kHz, which is approximately the resonance frequency of the piezoelectric transducers. Gain for generating oscillations is provided by a power hybrid operational amplifier (U1). A junction field-effect transistor (Q1) in combination with a resistor (R4) is used as a voltage-variable resistor to control the magnitude of the oscillation. The voltage-variable resistor is part of a feedback control loop: Part of the output of the oscillator is rectified and filtered for use as a slow negative feedback to the gate of Q1 to keep the output amplitude constant. The response of this control loop is much slower than 2 kHz and, therefore, does not introduce significant distortion of the oscillator output, which is a fairly clean sine wave. The positive AC feedback needed to sustain oscillations is derived from sampling the current through the

  4. Quantum Memristors with Superconducting Circuits

    NASA Astrophysics Data System (ADS)

    Salmilehto, J.; Deppe, F.; di Ventra, M.; Sanz, M.; Solano, E.

    2017-02-01

    Memristors are resistive elements retaining information of their past dynamics. They have garnered substantial interest due to their potential for representing a paradigm change in electronics, information processing and unconventional computing. Given the advent of quantum technologies, a design for a quantum memristor with superconducting circuits may be envisaged. Along these lines, we introduce such a quantum device whose memristive behavior arises from quasiparticle-induced tunneling when supercurrents are cancelled. For realistic parameters, we find that the relevant hysteretic behavior may be observed using current state-of-the-art measurements of the phase-driven tunneling current. Finally, we develop suitable methods to quantify memory retention in the system.

  5. Circuit Boards on Rover 2

    NASA Technical Reports Server (NTRS)

    2003-01-01

    April 15, 2003Prelaunch at Kennedy Space Center

    In the Payload Hazardous Servicing Facility, technicians remove one of the circuit boards on the Mars Exploration Rover 2 (MER-2). To gain access to the spacecraft, its lander petals were reopened and its solar panels deployed. A concern arose during prelaunch testing regarding how the spacecraft interprets signals sent from its main computer to peripherals in the cruise stage, lander and small deep space transponder. The MER Mission consists of two identical rovers set to launch in June 2003. The problem will be fixed on both rovers.

  6. Polysilicon photoconductor for integrated circuits

    DOEpatents

    Hammond, Robert B.; Bowman, Douglas R.

    1990-01-01

    A photoconductive element of polycrystalline silicon is provided with intrinsic response time which does not limit overall circuit response. An undoped polycrystalline silicon layer is deposited by LPCVD to a selected thickness on silicon dioxide. The deposited polycrystalline silicon is then annealed at a selected temperature and for a time effective to obtain crystal sizes effective to produce an enhanced current output. The annealed polycrystalline layer is subsequently exposed and damaged by ion implantation to a damage factor effective to obtain a fast photoconductive response.

  7. Polysilicon photoconductor for integrated circuits

    DOEpatents

    Hammond, R.B.; Bowman, D.R.

    1989-04-11

    A photoconductive element of polycrystalline silicon is provided with intrinsic response time which does not limit overall circuit response. An undoped polycrystalline silicon layer is deposited by LPCVD to a selected thickness on silicon dioxide. The deposited polycrystalline silicon is then annealed at a selected temperature and for a time effective to obtain crystal sizes effective to produce an enhanced current output. The annealed polycrystalline layer is subsequently exposed and damaged by ion implantation to a damage factor effective to obtain a fast photoconductive response. 6 figs.

  8. Polysilicon photoconductor for integrated circuits

    DOEpatents

    Hammond, Robert B.; Bowman, Douglas R.

    1989-01-01

    A photoconductive element of polycrystalline silicon is provided with intrinsic response time which does not limit overall circuit response. An undoped polycrystalline silicon layer is deposited by LPCVD to a selected thickness on silicon dioxide. The deposited polycrystalline silicon is then annealed at a selected temperature and for a time effective to obtain crystal sizes effective to produce an enhanced current output. The annealed polycrystalline layer is subsequently exposed and damaged by ion implantation to a damage factor effective to obtain a fast photoconductive response.

  9. Neurogliaform Cells in Cortical Circuits

    PubMed Central

    Overstreet-Wadiche, Linda; McBain, Chris J.

    2016-01-01

    Recent research into local circuit GABAergic inhibitory interneurons of the mammalian central nervous system has provided unprecedented insight into our understanding of the mechanics of neuronal circuitry and its dysfunction. The recognition that inhibitory interneurons represent a broad array of anatomically and neurochemically diverse cell types suggests that each occupy an equally diverse functional role. Although neurogliaform cells were observed by Cajal over a century ago, our understanding of their functional roles is in its infancy. However, it is rapidly becoming clear that this cell type operates under a distinct repertoire of rules to provide novel forms of inhibitory control of numerous afferent pathways. PMID:26189693

  10. Printed circuit dispersive transmission line

    DOEpatents

    Ikezi, Hiroyuki; Lin-Liu, Yuh-Ren; DeGrassie, John S.

    1991-01-01

    A printed circuit dispersive transmission line structure is disclosed comprising an insulator, a ground plane formed on one surface of the insulator, a first transmission line formed on a second surface of the insulator, and a second transmission line also formed on the second surface of the insulator and of longer length than the first transmission line and periodically intersecting the first transmission line. In a preferred embodiment, the transmission line structure exhibits highly dispersive characteristics by designing the length of one of the transmission line between two adjacent periodic intersections to be longer than the other.

  11. Printed circuit dispersive transmission line

    DOEpatents

    Ikezi, H.; Lin-Liu, Y.R.; DeGrassie, J.S.

    1991-08-27

    A printed circuit dispersive transmission line structure is disclosed comprising an insulator, a ground plane formed on one surface of the insulator, a first transmission line formed on a second surface of the insulator, and a second transmission line also formed on the second surface of the insulator and of longer length than the first transmission line and periodically intersecting the first transmission line. In a preferred embodiment, the transmission line structure exhibits highly dispersive characteristics by designing the length of one of the transmission line between two adjacent periodic intersections to be longer than the other. 5 figures.

  12. Circuit considerations for repetitive railguns

    SciTech Connect

    Honih, E.M.

    1986-01-01

    Railgun electromagnetic launchers have significant military and scientific potential. They provide direct conversion of electrical energy to projectile kinetic energy, and they offer the hope of achieving projectile velocities greatly exceeding the limits of conventional guns. With over 10 km/sec already demonstrated, railguns are attracting attention for tactical and strategic weapons systems and for scientific equation-of-state research. The full utilization of railguns will require significant improvements in every aspect of system design - projectile, barrel, and power source - to achieve operation on a large scale. This paper will review fundamental aspects of railguns, with emphasis on circuit considerations and repetitive operation.

  13. Quantum Memristors with Superconducting Circuits.

    PubMed

    Salmilehto, J; Deppe, F; Di Ventra, M; Sanz, M; Solano, E

    2017-02-14

    Memristors are resistive elements retaining information of their past dynamics. They have garnered substantial interest due to their potential for representing a paradigm change in electronics, information processing and unconventional computing. Given the advent of quantum technologies, a design for a quantum memristor with superconducting circuits may be envisaged. Along these lines, we introduce such a quantum device whose memristive behavior arises from quasiparticle-induced tunneling when supercurrents are cancelled. For realistic parameters, we find that the relevant hysteretic behavior may be observed using current state-of-the-art measurements of the phase-driven tunneling current. Finally, we develop suitable methods to quantify memory retention in the system.

  14. Coded source neutron imaging

    SciTech Connect

    Bingham, Philip R; Santos-Villalobos, Hector J

    2011-01-01

    Coded aperture techniques have been applied to neutron radiography to address limitations in neutron flux and resolution of neutron detectors in a system labeled coded source imaging (CSI). By coding the neutron source, a magnified imaging system is designed with small spot size aperture holes (10 and 100 m) for improved resolution beyond the detector limits and with many holes in the aperture (50% open) to account for flux losses due to the small pinhole size. An introduction to neutron radiography and coded aperture imaging is presented. A system design is developed for a CSI system with a development of equations for limitations on the system based on the coded image requirements and the neutron source characteristics of size and divergence. Simulation has been applied to the design using McStas to provide qualitative measures of performance with simulations of pinhole array objects followed by a quantitative measure through simulation of a tilted edge and calculation of the modulation transfer function (MTF) from the line spread function. MTF results for both 100um and 10um aperture hole diameters show resolutions matching the hole diameters.

  15. Coded source neutron imaging

    NASA Astrophysics Data System (ADS)

    Bingham, Philip; Santos-Villalobos, Hector; Tobin, Ken

    2011-03-01

    Coded aperture techniques have been applied to neutron radiography to address limitations in neutron flux and resolution of neutron detectors in a system labeled coded source imaging (CSI). By coding the neutron source, a magnified imaging system is designed with small spot size aperture holes (10 and 100μm) for improved resolution beyond the detector limits and with many holes in the aperture (50% open) to account for flux losses due to the small pinhole size. An introduction to neutron radiography and coded aperture imaging is presented. A system design is developed for a CSI system with a development of equations for limitations on the system based on the coded image requirements and the neutron source characteristics of size and divergence. Simulation has been applied to the design using McStas to provide qualitative measures of performance with simulations of pinhole array objects followed by a quantitative measure through simulation of a tilted edge and calculation of the modulation transfer function (MTF) from the line spread function. MTF results for both 100μm and 10μm aperture hole diameters show resolutions matching the hole diameters.

  16. An efficient decoding for low density parity check codes

    NASA Astrophysics Data System (ADS)

    Zhao, Ling; Zhang, Xiaolin; Zhu, Manjie

    2009-12-01

    Low density parity check (LDPC) codes are a class of forward-error-correction codes. They are among the best-known codes capable of achieving low bit error rates (BER) approaching Shannon's capacity limit. Recently, LDPC codes have been adopted by the European Digital Video Broadcasting (DVB-S2) standard, and have also been proposed for the emerging IEEE 802.16 fixed and mobile broadband wireless-access standard. The consultative committee for space data system (CCSDS) has also recommended using LDPC codes in the deep space communications and near-earth communications. It is obvious that LDPC codes will be widely used in wired and wireless communication, magnetic recording, optical networking, DVB, and other fields in the near future. Efficient hardware implementation of LDPC codes is of great interest since LDPC codes are being considered for a wide range of applications. This paper presents an efficient partially parallel decoder architecture suited for quasi-cyclic (QC) LDPC codes using Belief propagation algorithm for decoding. Algorithmic transformation and architectural level optimization are incorporated to reduce the critical path. First, analyze the check matrix of LDPC code, to find out the relationship between the row weight and the column weight. And then, the sharing level of the check node updating units (CNU) and the variable node updating units (VNU) are determined according to the relationship. After that, rearrange the CNU and the VNU, and divide them into several smaller parts, with the help of some assistant logic circuit, these smaller parts can be grouped into CNU during the check node update processing and grouped into VNU during the variable node update processing. These smaller parts are called node update kernel units (NKU) and the assistant logic circuit are called node update auxiliary unit (NAU). With NAUs' help, the two steps of iteration operation are completed by NKUs, which brings in great hardware resource reduction. Meanwhile

  17. Implementation of generalized quantum measurements: Superadditive quantum coding, accessible information extraction, and classical capacity limit

    SciTech Connect

    Takeoka, Masahiro; Fujiwara, Mikio; Mizuno, Jun; Sasaki, Masahide

    2004-05-01

    Quantum-information theory predicts that when the transmission resource is doubled in quantum channels, the amount of information transmitted can be increased more than twice by quantum-channel coding technique, whereas the increase is at most twice in classical information theory. This remarkable feature, the superadditive quantum-coding gain, can be implemented by appropriate choices of code words and corresponding quantum decoding which requires a collective quantum measurement. Recently, an experimental demonstration was reported [M. Fujiwara et al., Phys. Rev. Lett. 90, 167906 (2003)]. The purpose of this paper is to describe our experiment in detail. Particularly, a design strategy of quantum-collective decoding in physical quantum circuits is emphasized. We also address the practical implication of the gain on communication performance by introducing the quantum-classical hybrid coding scheme. We show how the superadditive quantum-coding gain, even in a small code length, can boost the communication performance of conventional coding techniques.

  18. Cortical circuits for perceptual inference.

    PubMed

    Friston, Karl; Kiebel, Stefan

    2009-10-01

    This paper assumes that cortical circuits have evolved to enable inference about the causes of sensory input received by the brain. This provides a principled specification of what neural circuits have to achieve. Here, we attempt to address how the brain makes inferences by casting inference as an optimisation problem. We look at how the ensuing recognition dynamics could be supported by directed connections and message-passing among neuronal populations, given our knowledge of intrinsic and extrinsic neuronal connections. We assume that the brain models the world as a dynamic system, which imposes causal structure on the sensorium. Perception is equated with the optimisation or inversion of this internal model, to explain sensory input. Given a model of how sensory data are generated, we use a generic variational approach to model inversion to furnish equations that prescribe recognition; i.e., the dynamics of neuronal activity that represents the causes of sensory input. Here, we focus on a model whose hierarchical and dynamical structure enables simulated brains to recognise and predict sequences of sensory states. We first review these models and their inversion under a variational free-energy formulation. We then show that the brain has the necessary infrastructure to implement this inversion and present stimulations using synthetic birds that generate and recognise birdsongs.

  19. Parallelism in integrated fluidic circuits

    NASA Astrophysics Data System (ADS)

    Bousse, Luc J.; Kopf-Sill, Anne R.; Parce, J. W.

    1998-04-01

    Many research groups around the world are working on integrated microfluidics. The goal of these projects is to automate and integrate the handling of liquid samples and reagents for measurement and assay procedures in chemistry and biology. Ultimately, it is hoped that this will lead to a revolution in chemical and biological procedures similar to that caused in electronics by the invention of the integrated circuit. The optimal size scale of channels for liquid flow is determined by basic constraints to be somewhere between 10 and 100 micrometers . In larger channels, mixing by diffusion takes too long; in smaller channels, the number of molecules present is so low it makes detection difficult. At Caliper, we are making fluidic systems in glass chips with channels in this size range, based on electroosmotic flow, and fluorescence detection. One application of this technology is rapid assays for drug screening, such as enzyme assays and binding assays. A further challenge in this area is to perform multiple functions on a chip in parallel, without a large increase in the number of inputs and outputs. A first step in this direction is a fluidic serial-to-parallel converter. Fluidic circuits will be shown with the ability to distribute an incoming serial sample stream to multiple parallel channels.

  20. Layout techniques for integrated circuits

    SciTech Connect

    Tsay, C.Y.

    1986-01-01

    Several techniques are presented for solving circuit-layout problems. In particular, a channel-placement algorithm is first introduced to reduce the channel density (d) so that a channel router can complete the routing requirements in fewer tracks. A 4-layer channel-routing model is then formulated so that a general channel routing problem (CRP) with cyclic conflicts and long critical paths can be completed with d/2. Finally, the 4-layer, 2-dimensional switchbox routing problem needed to enhance the channel routing in general circuit layout is investigated from the graph-theoretical viewpoint. The channel-placement technique consists of two phases. Using the principle of decomposition, the initial placement phase effectively reduces the complexity of the problem and, therefore, improves the efficiency of the second phase, which is called the iterative improvement placement. The main feature of this phase is its hill-climbing ability to avoid being trapped at local minima. The combination of these two phases leads to an efficient technique for standard cell placement. To utilize multi-layer technology, a new 4-layer channel routing model is introduced to minimize the channel width of more-generalized CRP's. The 2-dimensional switchbox routing problem is transformed to an equivalent graph-theoretical problem.

  1. Linking oscillations in cerebellar circuits

    PubMed Central

    Courtemanche, Richard; Robinson, Jennifer C.; Aponte, Daniel I.

    2013-01-01

    In many neuroscience fields, the study of local and global rhythmicity has been receiving increasing attention. These network influences could directly impact on how neuronal groups interact together, organizing for different contexts. The cerebellar cortex harbors a variety of such local circuit rhythms, from the rhythms in the cerebellar cortex per se, or those dictated from important afferents. We present here certain cerebellar oscillatory phenomena that have been recorded in rodents and primates. Those take place in a range of frequencies: from the more known oscillations in the 4–25 Hz band, such as the olivocerebellar oscillatory activity and the granule cell layer oscillations, to the more recently reported slow (<1 Hz oscillations), and the fast (>150 Hz) activity in the Purkinje cell layer. Many of these oscillations appear spontaneously in the circuits, and are modulated by behavioral imperatives. We review here how those oscillations are recorded, some of their modulatory mechanisms, and also identify some of the cerebellar nodes where they could interact. A particular emphasis has been placed on how these oscillations could be modulated by movement and certain neuropathological manifestations. Many of those oscillations could have a definite impact on the way information is processed in the cerebellum and how it interacts with other structures in a variety of contexts. PMID:23908606

  2. Code query by example

    NASA Astrophysics Data System (ADS)

    Vaucouleur, Sebastien

    2011-02-01

    We introduce code query by example for customisation of evolvable software products in general and of enterprise resource planning systems (ERPs) in particular. The concept is based on an initial empirical study on practices around ERP systems. We motivate our design choices based on those empirical results, and we show how the proposed solution helps with respect to the infamous upgrade problem: the conflict between the need for customisation and the need for upgrade of ERP systems. We further show how code query by example can be used as a form of lightweight static analysis, to detect automatically potential defects in large software products. Code query by example as a form of lightweight static analysis is particularly interesting in the context of ERP systems: it is often the case that programmers working in this field are not computer science specialists but more of domain experts. Hence, they require a simple language to express custom rules.

  3. Seals Code Development Workshop

    NASA Technical Reports Server (NTRS)

    Hendricks, Robert C. (Compiler); Liang, Anita D. (Compiler)

    1996-01-01

    Seals Workshop of 1995 industrial code (INDSEAL) release include ICYL, GCYLT, IFACE, GFACE, SPIRALG, SPIRALI, DYSEAL, and KTK. The scientific code (SCISEAL) release includes conjugate heat transfer and multidomain with rotordynamic capability. Several seals and bearings codes (e.g., HYDROFLEX, HYDROTRAN, HYDROB3D, FLOWCON1, FLOWCON2) are presented and results compared. Current computational and experimental emphasis includes multiple connected cavity flows with goals of reducing parasitic losses and gas ingestion. Labyrinth seals continue to play a significant role in sealing with face, honeycomb, and new sealing concepts under investigation for advanced engine concepts in view of strict environmental constraints. The clean sheet approach to engine design is advocated with program directions and anticipated percentage SFC reductions cited. Future activities center on engine applications with coupled seal/power/secondary flow streams.

  4. SAC: Sheffield Advanced Code

    NASA Astrophysics Data System (ADS)

    Griffiths, Mike; Fedun, Viktor; Mumford, Stuart; Gent, Frederick

    2013-06-01

    The Sheffield Advanced Code (SAC) is a fully non-linear MHD code designed for simulations of linear and non-linear wave propagation in gravitationally strongly stratified magnetized plasma. It was developed primarily for the forward modelling of helioseismological processes and for the coupling processes in the solar interior, photosphere, and corona; it is built on the well-known VAC platform that allows robust simulation of the macroscopic processes in gravitationally stratified (non-)magnetized plasmas. The code has no limitations of simulation length in time imposed by complications originating from the upper boundary, nor does it require implementation of special procedures to treat the upper boundaries. SAC inherited its modular structure from VAC, thereby allowing modification to easily add new physics.

  5. Autocatalysis, information and coding.

    PubMed

    Wills, P R

    2001-01-01

    Autocatalytic self-construction in macromolecular systems requires the existence of a reflexive relationship between structural components and the functional operations they perform to synthesise themselves. The possibility of reflexivity depends on formal, semiotic features of the catalytic structure-function relationship, that is, the embedding of catalytic functions in the space of polymeric structures. Reflexivity is a semiotic property of some genetic sequences. Such sequences may serve as the basis for the evolution of coding as a result of autocatalytic self-organisation in a population of assignment catalysts. Autocatalytic selection is a mechanism whereby matter becomes differentiated in primitive biochemical systems. In the case of coding self-organisation, it corresponds to the creation of symbolic information. Prions are present-day entities whose replication through autocatalysis reflects aspects of biological semiotics less obvious than genetic coding.

  6. Development of larval motor circuits in Drosophila.

    PubMed

    Kohsaka, Hiroshi; Okusawa, Satoko; Itakura, Yuki; Fushiki, Akira; Nose, Akinao

    2012-04-01

    How are functional neural circuits formed during development? Despite recent advances in our understanding of the development of individual neurons, little is known about how complex circuits are assembled to generate specific behaviors. Here, we describe the ways in which Drosophila motor circuits serve as an excellent model system to tackle this problem. We first summarize what has been learned during the past decades on the connectivity and development of component neurons, in particular motor neurons and sensory feedback neurons. We then review recent progress in our understanding of the development of the circuits as well as studies that apply optogenetics and other innovative techniques to dissect the circuit diagram. New approaches using Drosophila as a model system are now making it possible to search for developmental rules that regulate the construction of neural circuits.

  7. Analog VLSI neural network integrated circuits

    NASA Technical Reports Server (NTRS)

    Kub, F. J.; Moon, K. K.; Just, E. A.

    1991-01-01

    Two analog very large scale integration (VLSI) vector matrix multiplier integrated circuit chips were designed, fabricated, and partially tested. They can perform both vector-matrix and matrix-matrix multiplication operations at high speeds. The 32 by 32 vector-matrix multiplier chip and the 128 by 64 vector-matrix multiplier chip were designed to perform 300 million and 3 billion multiplications per second, respectively. An additional circuit that has been developed is a continuous-time adaptive learning circuit. The performance achieved thus far for this circuit is an adaptivity of 28 dB at 300 KHz and 11 dB at 15 MHz. This circuit has demonstrated greater than two orders of magnitude higher frequency of operation than any previous adaptive learning circuit.

  8. Deconstruction of a neural circuit for hunger

    PubMed Central

    Atasoy, Deniz; Betley, J. Nicholas; Su, Helen H.; Sternson, Scott M.

    2012-01-01

    Hunger is a complex behavioural state that elicits intense food seeking and consumption. These behaviours are rapidly recapitulated by activation of starvation-sensitive AGRP neurons, which present an entry point for reverse-engineering neural circuits for hunger. We mapped synaptic interactions of AGRP neurons with multiple cell populations and probed the contribution of these distinct circuits to feeding behaviour using optogenetic and pharmacogenetic techniques. An inhibitory circuit with paraventricular hypothalamus (PVH) neurons substantially accounted for acute AGRP neuron-evoked eating, whereas two other prominent circuits were insufficient. Within the PVH, we found that AGRP neurons target and inhibit oxytocin neurons, a small population that is selectively lost in Prader-Willi syndrome, a condition involving insatiable hunger. By developing strategies for evaluating molecularly-defined circuits, we show that AGRP neuron suppression of oxytocin neurons is critical for evoked feeding. These experiments reveal a new neural circuit that regulates hunger state and pathways associated with overeating disorders. PMID:22801496

  9. Diode-quad bridge circuit means

    NASA Technical Reports Server (NTRS)

    Harrison, D. R.; Dimeff, J. (Inventor)

    1975-01-01

    Diode-quad bridge circuit means is described for use as a transducer circuit or as a discriminator circuit. It includes: (1) a diode bridge having first, second, third, and fourth bridge terminals consecutively coupled together by four diodes polarized in circulating relationship; (2) a first impedance connected between the second bridge terminal and a circuit ground; (3) a second impedance connected between the fourth bridge terminal and the circuit ground; (4) a signal source having a first source terminal capacitively coupled to the first and third bridge terminals, and a second source terminal connected to the circuit ground; and (5) an output terminal coupled to the first bridge terminal and at which an output signal may be taken.

  10. Deconstruction of a neural circuit for hunger.

    PubMed

    Atasoy, Deniz; Betley, J Nicholas; Su, Helen H; Sternson, Scott M

    2012-08-09

    Hunger is a complex behavioural state that elicits intense food seeking and consumption. These behaviours are rapidly recapitulated by activation of starvation-sensitive AGRP neurons, which present an entry point for reverse-engineering neural circuits for hunger. Here we mapped synaptic interactions of AGRP neurons with multiple cell populations in mice and probed the contribution of these distinct circuits to feeding behaviour using optogenetic and pharmacogenetic techniques. An inhibitory circuit with paraventricular hypothalamus (PVH) neurons substantially accounted for acute AGRP neuron-evoked eating, whereas two other prominent circuits were insufficient. Within the PVH, we found that AGRP neurons target and inhibit oxytocin neurons, a small population that is selectively lost in Prader-Willi syndrome, a condition involving insatiable hunger. By developing strategies for evaluating molecularly defined circuits, we show that AGRP neuron suppression of oxytocin neurons is critical for evoked feeding. These experiments reveal a new neural circuit that regulates hunger state and pathways associated with overeating disorders.

  11. Code inspection instructional validation

    NASA Technical Reports Server (NTRS)

    Orr, Kay; Stancil, Shirley

    1992-01-01

    The Shuttle Data Systems Branch (SDSB) of the Flight Data Systems Division (FDSD) at Johnson Space Center contracted with Southwest Research Institute (SwRI) to validate the effectiveness of an interactive video course on the code inspection process. The purpose of this project was to determine if this course could be effective for teaching NASA analysts the process of code inspection. In addition, NASA was interested in the effectiveness of this unique type of instruction (Digital Video Interactive), for providing training on software processes. This study found the Carnegie Mellon course, 'A Cure for the Common Code', effective for teaching the process of code inspection. In addition, analysts prefer learning with this method of instruction, or this method in combination with other methods. As is, the course is definitely better than no course at all; however, findings indicate changes are needed. Following are conclusions of this study. (1) The course is instructionally effective. (2) The simulation has a positive effect on student's confidence in his ability to apply new knowledge. (3) Analysts like the course and prefer this method of training, or this method in combination with current methods of training in code inspection, over the way training is currently being conducted. (4) Analysts responded favorably to information presented through scenarios incorporating full motion video. (5) Some course content needs to be changed. (6) Some content needs to be added to the course. SwRI believes this study indicates interactive video instruction combined with simulation is effective for teaching software processes. Based on the conclusions of this study, SwRI has outlined seven options for NASA to consider. SwRI recommends the option which involves creation of new source code and data files, but uses much of the existing content and design from the current course. Although this option involves a significant software development effort, SwRI believes this option

  12. Implications of electronics constraints for solid-state quantum error correction and quantum circuit failure probability

    NASA Astrophysics Data System (ADS)

    Levy, James E.; Carroll, Malcolm S.; Ganti, Anand; Phillips, Cynthia A.; Landahl, Andrew J.; Gurrieri, Thomas M.; Carr, Robert D.; Stalford, Harold L.; Nielsen, Erik

    2011-08-01

    In this paper we present the impact of classical electronics constraints on a solid-state quantum dot logical qubit architecture. Constraints due to routing density, bandwidth allocation, signal timing and thermally aware placement of classical supporting electronics significantly affect the quantum error correction circuit's error rate (by a factor of ~3-4 in our specific analysis). We analyze one level of a quantum error correction circuit using nine data qubits in a Bacon-Shor code configured as a quantum memory. A hypothetical silicon double quantum dot quantum bit (qubit) is used as the fundamental element. A pessimistic estimate of the error probability of the quantum circuit is calculated using the total number of gates and idle time using a provably optimal schedule for the circuit operations obtained with an integer program methodology. The micro-architecture analysis provides insight about the different ways the electronics impact the circuit performance (e.g. extra idle time in the schedule), which can significantly limit the ultimate performance of any quantum circuit and therefore is a critical foundation for any future larger scale architecture analysis.

  13. Polar Code Validation

    DTIC Science & Technology

    1989-09-30

    Unclassified 2a SECURITY CLASSiF-ICATiON AUTHORIT’Y 3 DIStRIBUTION AVAILABILITY OF REPORT N,A Approved for public release; 2o DECLASSIFICAIiON DOWNGRADING SCH DI...SUMMARY OF POLAR ACHIEVEMENTS ..... .......... 3 3 . POLAR CODE PHYSICAL MODELS ..... ............. 5 3.1 PL-ASMA Su ^"ru5 I1LS SH A...11 Structure of the Bipolar Plasma Sheath Generated by SPEAR I ... ...... 1 3 The POLAR Code Wake Model: Comparison with in Situ Observations . . 23

  14. Aeroacoustic Prediction Codes

    NASA Technical Reports Server (NTRS)

    Gliebe, P; Mani, R.; Shin, H.; Mitchell, B.; Ashford, G.; Salamah, S.; Connell, S.; Huff, Dennis (Technical Monitor)

    2000-01-01

    This report describes work performed on Contract NAS3-27720AoI 13 as part of the NASA Advanced Subsonic Transport (AST) Noise Reduction Technology effort. Computer codes were developed to provide quantitative prediction, design, and analysis capability for several aircraft engine noise sources. The objective was to provide improved, physics-based tools for exploration of noise-reduction concepts and understanding of experimental results. Methods and codes focused on fan broadband and 'buzz saw' noise and on low-emissions combustor noise and compliment work done by other contractors under the NASA AST program to develop methods and codes for fan harmonic tone noise and jet noise. The methods and codes developed and reported herein employ a wide range of approaches, from the strictly empirical to the completely computational, with some being semiempirical analytical, and/or analytical/computational. Emphasis was on capturing the essential physics while still considering method or code utility as a practical design and analysis tool for everyday engineering use. Codes and prediction models were developed for: (1) an improved empirical correlation model for fan rotor exit flow mean and turbulence properties, for use in predicting broadband noise generated by rotor exit flow turbulence interaction with downstream stator vanes: (2) fan broadband noise models for rotor and stator/turbulence interaction sources including 3D effects, noncompact-source effects. directivity modeling, and extensions to the rotor supersonic tip-speed regime; (3) fan multiple-pure-tone in-duct sound pressure prediction methodology based on computational fluid dynamics (CFD) analysis; and (4) low-emissions combustor prediction methodology and computer code based on CFD and actuator disk theory. In addition. the relative importance of dipole and quadrupole source mechanisms was studied using direct CFD source computation for a simple cascadeigust interaction problem, and an empirical combustor

  15. Securing mobile code.

    SciTech Connect

    Link, Hamilton E.; Schroeppel, Richard Crabtree; Neumann, William Douglas; Campbell, Philip LaRoche; Beaver, Cheryl Lynn; Pierson, Lyndon George; Anderson, William Erik

    2004-10-01

    If software is designed so that the software can issue functions that will move that software from one computing platform to another, then the software is said to be 'mobile'. There are two general areas of security problems associated with mobile code. The 'secure host' problem involves protecting the host from malicious mobile code. The 'secure mobile code' problem, on the other hand, involves protecting the code from malicious hosts. This report focuses on the latter problem. We have found three distinct camps of opinions regarding how to secure mobile code. There are those who believe special distributed hardware is necessary, those who believe special distributed software is necessary, and those who believe neither is necessary. We examine all three camps, with a focus on the third. In the distributed software camp we examine some commonly proposed techniques including Java, D'Agents and Flask. For the specialized hardware camp, we propose a cryptographic technique for 'tamper-proofing' code over a large portion of the software/hardware life cycle by careful modification of current architectures. This method culminates by decrypting/authenticating each instruction within a physically protected CPU, thereby protecting against subversion by malicious code. Our main focus is on the camp that believes that neither specialized software nor hardware is necessary. We concentrate on methods of code obfuscation to render an entire program or a data segment on which a program depends incomprehensible. The hope is to prevent or at least slow down reverse engineering efforts and to prevent goal-oriented attacks on the software and execution. The field of obfuscation is still in a state of development with the central problem being the lack of a basis for evaluating the protection schemes. We give a brief introduction to some of the main ideas in the field, followed by an in depth analysis of a technique called 'white-boxing'. We put forth some new attacks and improvements

  16. Integrated-Circuit Pseudorandom-Number Generator

    NASA Technical Reports Server (NTRS)

    Steelman, James E.; Beasley, Jeff; Aragon, Michael; Ramirez, Francisco; Summers, Kenneth L.; Knoebel, Arthur

    1992-01-01

    Integrated circuit produces 8-bit pseudorandom numbers from specified probability distribution, at rate of 10 MHz. Use of Boolean logic, circuit implements pseudorandom-number-generating algorithm. Circuit includes eight 12-bit pseudorandom-number generators, outputs are uniformly distributed. 8-bit pseudorandom numbers satisfying specified nonuniform probability distribution are generated by processing uniformly distributed outputs of eight 12-bit pseudorandom-number generators through "pipeline" of D flip-flops, comparators, and memories implementing conditional probabilities on zeros and ones.

  17. Expert system to design communications circuits

    SciTech Connect

    Tolendino, L.F.; Vahle, M.O.

    1986-07-01

    An expert system has been created to aid the design of fiber optic based communications circuits. The design system is based on an Apollo workstation, LISP and CPSL, an in-house developed expert system language. The optical circuit is taken from design specification through hardware selection and circuit routing to the production of detailed schematics and routing guides. A database containing the entire fiber optic trunk system is also maintained.

  18. Novel circuit theory of Andreev reflection

    NASA Astrophysics Data System (ADS)

    Nazarov, Yuli V.

    1999-05-01

    We review here a novel circuit theory of superconductivity. The existing circuit theory of Andreev reflection has been revised to account for decoherence between electrons and holes and the twofold nature of the distribution function. The description of arbitrary connectors has been elaborated on. In this way one can cope with most of the factors that limited the applicability of the old circuit theory. We give a simple example and discuss numerical implementation of the theory.

  19. Combinational Circuit Obfuscation Through Power Signature Manipulation

    DTIC Science & Technology

    2011-06-01

    hardware descrip- tion files such as VHDL , SPICE netlist are needed for the SPICE-like simulation tools; however, the SID just needs a simple circuit...Time Interval) Figure 3.12: The Summary of Procedure for SPICE Simulation CORGI 3.0 XML Exporter Truth Table Exporter GraphML Exporter VHDL Exporter...encryption system developed by Falkinburg [4]. For installing the obfuscated version of a circuit into the test-bed, the circuit is described in VHDL format

  20. Electronic circuits for communications systems: A compilation

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The compilation of electronic circuits for communications systems is divided into thirteen basic categories, each representing an area of circuit design and application. The compilation items are moderately complex and, as such, would appeal to the applications engineer. However, the rationale for the selection criteria was tailored so that the circuits would reflect fundamental design principles and applications, with an additional requirement for simplicity whenever possible.

  1. A microwave dielectric resonant oscillatory circuit

    NASA Astrophysics Data System (ADS)

    Sigov, A. S.; Shvartsburg, A. B.

    2016-07-01

    Bias currents in a thin dielectric nonconducting torus are investigated, and the resonant mode of excitation of these currents is established. The similarity of the frequency spectrum of such a dielectric element to the spectra of a classical Thomson oscillatory circuit and a metamaterial with negative permittivity is demonstrated. The resonant frequency of electromagnetic oscillations of the ring dielectric circuit and magnetic and electric fields of such a circuit under resonant excitation are determined.

  2. Cost optimization in low volume VLSI circuits

    NASA Technical Reports Server (NTRS)

    Cook, K. B., Jr.; Kerns, D. V., Jr.

    1982-01-01

    The relationship of integrated circuit (IC) cost to electronic system cost is developed using models for integrated circuit cost which are based on design/fabrication approach. Emphasis is on understanding the relationship between cost and volume for custom circuits suitable for NASA applications. In this report, reliability is a major consideration in the models developed. Results are given for several typical IC designs using off the shelf, full custom, and semicustom IC's with single and double level metallization.

  3. Monitoring transients in low inductance circuits

    DOEpatents

    Guilford, R.P.; Rosborough, J.R.

    1985-10-21

    The instant invention relates to methods of and apparatus for monitoring transients in low inductance circuits and to a probe utilized to practice said method and apparatus. More particularly, the instant invention relates to methods of and apparatus for monitoring low inductance circuits, wherein the low inductance circuits include a pair of flat cable transmission lines. The instant invention is further directed to a probe for use in monitoring pairs of flat cable transmission lines.

  4. Starter circuit for an ion engine

    NASA Technical Reports Server (NTRS)

    Cardwell, Jr., Gilbert I. (Inventor); Phelps, Thomas K. (Inventor)

    2002-01-01

    A starter circuit particularly suitable for a plasma of an ion engine for a spacecraft includes a power supply having an output inductor with a tap. A switch is coupled to the tap. The switch has a control input. A pulse control logic circuit is coupled to said control input, said pulse control logic circuit controlling said switch to an off state to generate a high voltage discharge.

  5. Starter circuit for an ion engine

    NASA Technical Reports Server (NTRS)

    Cardwell, Jr., Gilbert I. (Inventor); Phelps, Thomas K. (Inventor)

    2001-01-01

    A starter circuit particularly suitable for a plasma of an ion engine for a spacecraft includes a power supply having an output inductor with a tap. A switch is coupled to the tap. The switch has a control input. A pulse control logic circuit is coupled to said control input, said pulse control logic circuit controlling said switch to an off state to generate a high voltage discharge.

  6. Multiplexer and time duration measuring circuit

    DOEpatents

    Gray, Jr., James

    1980-01-01

    A multiplexer device is provided for multiplexing data in the form of randomly developed, variable width pulses from a plurality of pulse sources to a master storage. The device includes a first multiplexer unit which includes a plurality of input circuits each coupled to one of the pulse sources, with all input circuits being disabled when one input circuit receives an input pulse so that only one input pulse is multiplexed by the multiplexer unit at any one time.

  7. DC circuits: II. Identification of foothold ideas in DC circuits

    NASA Astrophysics Data System (ADS)

    John, lgnatius; Allie, Saalih

    2017-01-01

    This is the second part of a broader investigation which explores the reasons behind the contextual variations in student responses at a fine-grained level. In the previous article (John 2017 Eur. J. Phys. 38 015701) it was established that the students’ responses are highly context dependent at a fine-grained level. This article presents the reason for the contextual variations of student responses from their free written responses. The result indicates that students who are being triggered by the productive resources during the engagement with the task will arrive at the correct (canonical) conclusion and those triggered by the unproductive resources will arrive at an incorrect conclusion. We identified the productive foothold ideas in a simple DC circuit with a single resistive element.

  8. Wafer-scale graphene integrated circuit.

    PubMed

    Lin, Yu-Ming; Valdes-Garcia, Alberto; Han, Shu-Jen; Farmer, Damon B; Meric, Inanc; Sun, Yanning; Wu, Yanqing; Dimitrakopoulos, Christos; Grill, Alfred; Avouris, Phaedon; Jenkins, Keith A

    2011-06-10

    A wafer-scale graphene circuit was demonstrated in which all circuit components, including graphene field-effect transistor and inductors, were monolithically integrated on a single silicon carbide wafer. The integrated circuit operates as a broadband radio-frequency mixer at frequencies up to 10 gigahertz. These graphene circuits exhibit outstanding thermal stability with little reduction in performance (less than 1 decibel) between 300 and 400 kelvin. These results open up possibilities of achieving practical graphene technology with more complex functionality and performance.

  9. Hybrid stretchable circuits on silicone substrate

    SciTech Connect

    Robinson, A. Aziz, A.; Liu, Q.; Suo, Z.; Lacour, S. P.

    2014-04-14

    When rigid and stretchable components are integrated onto a single elastic carrier substrate, large strain heterogeneities appear in the vicinity of the deformable-non-deformable interfaces. In this paper, we report on a generic approach to manufacture hybrid stretchable circuits where commercial electronic components can be mounted on a stretchable circuit board. Similar to printed circuit board development, the components are electrically bonded on the elastic substrate and interconnected with stretchable electrical traces. The substrate—a silicone matrix carrying concentric rigid disks—ensures both the circuit elasticity and the mechanical integrity of the most fragile materials.

  10. High temperature superconducting digital circuits and subsystems

    SciTech Connect

    Martens, J.S.; Pance, A.; Whiteley, S.R.; Char, K.; Johansson, M.F.; Lee, L.; Hietala, V.M.; Wendt, J.R.; Hou, S.Y.; Phillips, J.

    1993-10-01

    The advances in the fabrication of high temperature superconducting devices have enabled the demonstration of high performance and useful digital circuits and subsystems. The yield and uniformity of the devices is sufficient for circuit fabrication at the medium scale integration (MSI) level with performance not seen before at 77 K. The circuits demonstrated to date include simple gates, counters, analog to digital converters, and shift registers. All of these are mid-sized building blocks for potential applications in commercial and military systems. The processes used for these circuits and blocks will be discussed along with observed performance data.

  11. Predicting the reliability of electronic circuits.

    SciTech Connect

    Loescher, Douglas H.

    2004-06-01

    Procedures to predict the reliability of electrical circuits are discussed. Three cases are introduced and discussed. In Case 1, an analyst predicts the probability of any failure in the intended relations between circuit inputs and circuit outputs. In Case 2, an analyst predicts the probability that specified unintended outputs would occur. In Case 3, an analyst considers coupling between circuits. Logic models are given for the three cases, and sources of failure probabilities of components are mentioned. Methods of analysis are given, software tools are mentioned, and recommendations for presentation and review of results are discussed.

  12. High Speed Solid State Circuit Breaker

    NASA Technical Reports Server (NTRS)

    Podlesak, Thomas F.

    1993-01-01

    The U.S. Army Research Laboratory, Fort Monmouth, NJ, has developed and is installing two 3.3 MW high speed solid state circuit breakers at the Army's Pulse Power Center. These circuit breakers will interrupt 4160V three phase power mains in no more than 300 microseconds, two orders of magnitude faster than conventional mechanical contact type circuit breakers. These circuit breakers utilize Gate Turnoff Thyristors (GTO's) and are currently utility type devices using air cooling in an air conditioned enclosure. Future refinements include liquid cooling, either water or two phase organic coolant, and more advanced semiconductors. Each of these refinements promises a more compact, more reliable unit.

  13. Research in computer simulation of integrated circuits

    NASA Astrophysics Data System (ADS)

    Newton, A. R.; Pdederson, D. O.

    1983-07-01

    The performance of the new LSI simulator CLASSIE is evaluated on several circuits with a few hundred to over one thousand semiconductor devices. A more accurate run time prediction formula has been found to be appropriate for circuit simulators. The design decisions for optimal performance under the constraints of the hardware (CRAY-1) are presented. Vector computers have an increased potential for fast, accurate simulation at the transistor level of Large-Scale-Integrated Circuits. Design considerations for a new circuit simulator are developed based on the specifics of the vector computer architecture and of LSI circuits. The simulation of Large-Scale-Integrated (LSI) circuits requires very long run time on conventional circuit analysis programs such as SPICE2 and super-mini computers. A new simulator for LSI circuits, CLASSIE, which takes advantage of circuit hierarchy and repetitiveness, and array processors capable of high-speed floating-point computation are a promising combination. While a large number of powerful design verfication tools have been developed for IC design at the transistor and logic gate levels, there are very few silicon-oriented tools for architectural design and evaluation.

  14. Circuit For Control Of Electromechanical Prosthetic Hand

    NASA Technical Reports Server (NTRS)

    Bozeman, Richard J., Jr.

    1995-01-01

    Proposed circuit for control of electromechanical prosthetic hand derives electrical control signals from shoulder movements. Updated, electronic version of prosthesis, that includes two hooklike fingers actuated via cables from shoulder harness. Circuit built around favored shoulder harness, provides more dexterous movement, without incurring complexity of computer-controlled "bionic" or hydraulically actuated devices. Additional harness and potentiometer connected to similar control circuit mounted on other shoulder. Used to control stepping motor rotating hand about prosthetic wrist to one of number of angles consistent with number of digital outputs. Finger-control signals developed by circuit connected to first shoulder harness transmitted to prosthetic hand via sliprings at prosthetic wrist joint.

  15. Digital circuits for computer applications: A compilation

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The innovations in this updated series of compilations dealing with electronic technology represent a carefully selected collection of digital circuits which have direct application in computer oriented systems. In general, the circuits have been selected as representative items of each section and have been included on their merits of having universal applications in digital computers and digital data processing systems. As such, they should have wide appeal to the professional engineer and scientist who encounter the fundamentals of digital techniques in their daily activities. The circuits are grouped as digital logic circuits, analog to digital converters, and counters and shift registers.

  16. View of first bank of circuit towers on Arizona side ...

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

    View of first bank of circuit towers on Arizona side of canyon. Photograph taken from Nevada side of canyon. Left tower supports Circuit 8, second from left tower supports Circuit 9, middle tower supports Circuit 10, second from right tower supports Circuit 11, and right tower supports Circuit 12, view southeast. - Hoover Dam, Circuits 1-15, U.S. Highway 93, Boulder City, Clark County, NV

  17. Reliability of Physical Systems: Detection of Malicious Subcircuits (Trojan Circuits) in Sequential Circuits

    NASA Astrophysics Data System (ADS)

    Matrosova, A. Yu.; Kirienko, I. E.; Tomkov, V. V.; Miryutov, A. A.

    2016-12-01

    Reliability of physical systems is provided by reliability of their parts including logical ones. Insertion of malicious subcircuits that can destroy logical circuit or cause leakage of confidential information from a system necessitates the detection of such subcircuits followed by their masking if possible. We suggest a method of finding a set of sequential circuit nodes in which Trojan Circuits can be inserted. The method is based on random estimations of controllability and observability of combinational nodes calculated using a description of sequential circuit working area and an evidence of existence of a transfer sequence for the proper set of internal states without finding the sequence itself. The method allows cutting calculations using operations on Reduced Ordered Binary Decision Diagrams (ROBDDs) that can depend only on the state variables of the circuit. The approach, unlike traditional ones, does not require preliminary sequential circuit simulation but can use its results. It can be used when malicious circuits cannot be detected during sequential circuit verification.

  18. Sparse, Decorrelated Odor Coding in the Mushroom Body Enhances Learned Odor Discrimination

    PubMed Central

    Lin, Andrew C.; Bygrave, Alexei; de Calignon, Alix; Lee, Tzumin; Miesenböck, Gero

    2014-01-01

    Summary Sparse coding may be a general strategy of neural systems to augment memory capacity. In Drosophila, sparse odor coding by the Kenyon cells of the mushroom body is thought to generate a large number of precisely addressable locations for the storage of odor-specific memories. However, it remains untested how sparse coding relates to behavioral performance. Here we demonstrate that sparseness is controlled by a negative feedback circuit between Kenyon cells and the GABAergic anterior paired lateral (APL) neuron. Systematic activation and blockade of each leg of this feedback circuit show that Kenyon cells activate APL and APL inhibits Kenyon cells. Disrupting the Kenyon cell-APL feedback loop decreases the sparseness of Kenyon cell odor responses, increases inter-odor correlations, and prevents flies from learning to discriminate similar, but not dissimilar, odors. These results suggest that feedback inhibition suppresses Kenyon cell activity to maintain sparse, decorrelated odor coding and thus the odor-specificity of memories. PMID:24561998

  19. Normal and abnormal coding of painful sensations

    PubMed Central

    Prescott, Steven A; Ma, Qiufu; De Koninck, Yves

    2014-01-01

    Noxious stimuli cause pain and pain arises from noxious stimuli… usually. Exceptions to these apparent truisms are the basis for clinically important problems and provide valuable insight into the neural code for pain. In this Perspective, we will discuss how painful sensations are encoded. We will argue that although primary somatosensory afferents are specialized (i.e. tuned to specific stimulus features), natural stimuli often activate >1 type of afferent. Manipulating co-activation patterns can alter perception, which argues against each type of afferent acting independently (as expected for strictly labeled lines) and suggests instead that signals conveyed by different types of afferents interact. Deciphering the central circuits that mediate those interactions is critical for explaining the generation and modulation of neural signals ultimately perceived as pain. The advent of genetic and optical dissection techniques promise to dramatically accelerate progress towards this goal, which will facilitate the rational design of future pain therapeutics. PMID:24473266

  20. Coding for urologic office procedures.

    PubMed

    Dowling, Robert A; Painter, Mark

    2013-11-01

    This article summarizes current best practices for documenting, coding, and billing common office-based urologic procedures. Topics covered include general principles, basic and advanced urologic coding, creation of medical records that support compliant coding practices, bundled codes and unbundling, global periods, modifiers for procedure codes, when to bill for evaluation and management services during the same visit, coding for supplies, and laboratory and radiology procedures pertinent to urology practice. Detailed information is included for the most common urology office procedures, and suggested resources and references are provided. This information is of value to physicians, office managers, and their coding staff.

  1. Accumulate Repeat Accumulate Coded Modulation

    NASA Technical Reports Server (NTRS)

    Abbasfar, Aliazam; Divsalar, Dariush; Yao, Kung

    2004-01-01

    In this paper we propose an innovative coded modulation scheme called 'Accumulate Repeat Accumulate Coded Modulation' (ARA coded modulation). This class of codes can be viewed as serial turbo-like codes, or as a subclass of Low Density Parity Check (LDPC) codes that are combined with high level modulation. Thus at the decoder belief propagation can be used for iterative decoding of ARA coded modulation on a graph, provided a demapper transforms the received in-phase and quadrature samples to reliability of the bits.

  2. Dress Codes. Legal Brief.

    ERIC Educational Resources Information Center

    Zirkel, Perry A.

    2000-01-01

    As illustrated by two recent decisions, the courts in the past decade have demarcated wide boundaries for school officials considering dress codes, whether in the form of selective prohibitions or required uniforms. Administrators must warn the community, provide legitimate justification and reasonable clarity, and comply with state law. (MLH)

  3. Dress Codes and Uniforms.

    ERIC Educational Resources Information Center

    Lumsden, Linda; Miller, Gabriel

    2002-01-01

    Students do not always make choices that adults agree with in their choice of school dress. Dress-code issues are explored in this Research Roundup, and guidance is offered to principals seeking to maintain a positive school climate. In "Do School Uniforms Fit?" Kerry White discusses arguments for and against school uniforms and summarizes the…

  4. Building Codes and Regulations.

    ERIC Educational Resources Information Center

    Fisher, John L.

    The hazard of fire is of great concern to libraries due to combustible books and new plastics used in construction and interiors. Building codes and standards can offer architects and planners guidelines to follow but these standards should be closely monitored, updated, and researched for fire prevention. (DS)

  5. Student Dress Codes.

    ERIC Educational Resources Information Center

    Uerling, Donald F.

    School officials see a need for regulations that prohibit disruptive and inappropriate forms of expression and attire; students see these regulations as unwanted restrictions on their freedom. This paper reviews court litigation involving constitutional limitations on school authority, dress and hair codes, state law constraints, and school…

  6. Video Coding for ESL.

    ERIC Educational Resources Information Center

    King, Kevin

    1992-01-01

    Coding tasks, a valuable technique for teaching English as a Second Language, are presented that enable students to look at patterns and structures of marital communication as well as objectively evaluate the degree of happiness or distress in the marriage. (seven references) (JL)

  7. Multiple trellis coded modulation

    NASA Technical Reports Server (NTRS)

    Simon, Marvin K. (Inventor); Divsalar, Dariush (Inventor)

    1990-01-01

    A technique for designing trellis codes to minimize bit error performance for a fading channel. The invention provides a criteria which may be used in the design of such codes which is significantly different from that used for average white Gaussian noise channels. The method of multiple trellis coded modulation of the present invention comprises the steps of: (a) coding b bits of input data into s intermediate outputs; (b) grouping said s intermediate outputs into k groups of s.sub.i intermediate outputs each where the summation of all s.sub.i,s is equal to s and k is equal to at least 2; (c) mapping each of said k groups of intermediate outputs into one of a plurality of symbols in accordance with a plurality of modulation schemes, one for each group such that the first group is mapped in accordance with a first modulation scheme and the second group is mapped in accordance with a second modulation scheme; and (d) outputting each of said symbols to provide k output symbols for each b bits of input data.

  8. Coding Theory and Projective Spaces

    NASA Astrophysics Data System (ADS)

    Silberstein, Natalia

    2008-05-01

    The projective space of order n over a finite field F_q is a set of all subspaces of the vector space F_q^{n}. In this work, we consider error-correcting codes in the projective space, focusing mainly on constant dimension codes. We start with the different representations of subspaces in the projective space. These representations involve matrices in reduced row echelon form, associated binary vectors, and Ferrers diagrams. Based on these representations, we provide a new formula for the computation of the distance between any two subspaces in the projective space. We examine lifted maximum rank distance (MRD) codes, which are nearly optimal constant dimension codes. We prove that a lifted MRD code can be represented in such a way that it forms a block design known as a transversal design. The incidence matrix of the transversal design derived from a lifted MRD code can be viewed as a parity-check matrix of a linear code in the Hamming space. We find the properties of these codes which can be viewed also as LDPC codes. We present new bounds and constructions for constant dimension codes. First, we present a multilevel construction for constant dimension codes, which can be viewed as a generalization of a lifted MRD codes construction. This construction is based on a new type of rank-metric codes, called Ferrers diagram rank-metric codes. Then we derive upper bounds on the size of constant dimension codes which contain the lifted MRD code, and provide a construction for two families of codes, that attain these upper bounds. We generalize the well-known concept of a punctured code for a code in the projective space to obtain large codes which are not constant dimension. We present efficient enumerative encoding and decoding techniques for the Grassmannian. Finally we describe a search method for constant dimension lexicodes.

  9. TIME CALIBRATED OSCILLOSCOPE SWEEP CIRCUIT

    DOEpatents

    Smith, V.L.; Carstensen, H.K.

    1959-11-24

    An improved time calibrated sweep circuit is presented, which extends the range of usefulness of conventional oscilloscopes as utilized for time calibrated display applications in accordance with U. S. Patent No. 2,832,002. Principal novelty resides in the provision of a pair of separate signal paths, each of which is phase and amplitude adjustable, to connect a high-frequency calibration oscillator to the output of a sawtooth generator also connected to the respective horizontal deflection plates of an oscilloscope cathode ray tube. The amplitude and phase of the calibration oscillator signals in the two signal paths are adjusted to balance out feedthrough currents capacitively coupled at high frequencies of the calibration oscillator from each horizontal deflection plate to the vertical plates of the cathode ray tube.

  10. Semiconductor materials and microelectronic circuits

    NASA Astrophysics Data System (ADS)

    Kolesar, Edward S.

    Microminiaturization developments in IC systems have dramatically increased the reliability and performance of electronic components while reducing their physical size and power requirements; these advancements have pervasively affected weapons systems design efforts. Built-in self-test circuitry has greatly reduced maintenance problems and improved overall systems reliability. Increasing circuit complexity has also led to a major expansion of key military operational capabilities for reconnaissance, surveillance, and target acquisition. It is expected that Si-based ICs will continue to dominate high power solid-state switches in hypervelocity projectiles and beam weapons, while GaAs will remain the most commonly employed material in microwave and mm-wave devices for EW, radars, smart weapons, and communications.

  11. Shapeable short circuit resistant capacitor

    DOEpatents

    Taylor, Ralph S.; Myers, John D.; Baney, William J.

    2015-10-06

    A ceramic short circuit resistant capacitor that is bendable and/or shapeable to provide a multiple layer capacitor that is extremely compact and amenable to desirable geometries. The capacitor that exhibits a benign failure mode in which a multitude of discrete failure events result in a gradual loss of capacitance. Each event is a localized event in which localized heating causes an adjacent portion of one or both of the electrodes to vaporize, physically cleaning away electrode material from the failure site. A first metal electrode, a second metal electrode, and a ceramic dielectric layer between the electrodes are thin enough to be formed in a serpentine-arrangement with gaps between the first electrode and the second electrode that allow venting of vaporized electrode material in the event of a benign failure.

  12. Fault diagnosis of analog circuits

    NASA Astrophysics Data System (ADS)

    Bandler, J. W.; Salama, A. E.

    1985-08-01

    Theory and algorithms associated with four main categories of modern techniques used to locate faults in analog circuits are presented. These four general approaches are: the fault dictionary (FDA), the parameter identification (PIA), the fault verification (FVA), and the approximation (AA) approaches. The preliminaries and problems associated with the FDA, such as fault dictionary construction, the methods of optimum measurement selection, fault isolation criteria, and efficient methods of fault simulation, are discussed. The PIA techniques that utilize either linear or nonlinear systems of equations for identification of network elements are examined. Description of the FVA includes node-fault diagnosis, branch-fault diagnosis, subnetwork testability conditions, as well as combinatorial techniques, the failure-bound technique, and the network decomposition technique. In the AA, probabilistic methods and optimization-based methods are considered. In addition, the artificial intelligence technique and the different measures of testability are presented. A series of block diagrams is included.

  13. Sequential power-up circuit

    DOEpatents

    Kronberg, James W.

    1992-01-01

    A sequential power-up circuit for starting several electrical load elements in series to avoid excessive current surge, comprising a voltage ramp generator and a set of voltage comparators, each comparator having a different reference voltage and interfacing with a switch that is capable of turning on one of the load elements. As the voltage rises, it passes the reference voltages one at a time and causes the switch corresponding to that voltage to turn on its load element. The ramp is turned on and off by a single switch or by a logic-level electrical signal. The ramp rate for turning on the load element is relatively slow and the rate for turning the elements off is relatively fast. Optionally, the duration of each interval of time between the turning on of the load elements is programmable.

  14. 30 CFR 77.506 - Electric equipment and circuits; overload and short-circuit protection.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Electric equipment and circuits; overload and short-circuit protection. 77.506 Section 77.506 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... type and capacity shall be installed so as to protect all electric equipment and circuits against...

  15. 30 CFR 77.506 - Electric equipment and circuits; overload and short-circuit protection.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Electric equipment and circuits; overload and short-circuit protection. 77.506 Section 77.506 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... type and capacity shall be installed so as to protect all electric equipment and circuits against...

  16. 30 CFR 77.506 - Electric equipment and circuits; overload and short-circuit protection.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Electric equipment and circuits; overload and short-circuit protection. 77.506 Section 77.506 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... type and capacity shall be installed so as to protect all electric equipment and circuits against...

  17. 30 CFR 77.506 - Electric equipment and circuits; overload and short-circuit protection.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Electric equipment and circuits; overload and short-circuit protection. 77.506 Section 77.506 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... type and capacity shall be installed so as to protect all electric equipment and circuits against...

  18. 30 CFR 77.506 - Electric equipment and circuits; overload and short-circuit protection.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Electric equipment and circuits; overload and short-circuit protection. 77.506 Section 77.506 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... type and capacity shall be installed so as to protect all electric equipment and circuits against...

  19. Scaling of graphene integrated circuits

    NASA Astrophysics Data System (ADS)

    Bianchi, Massimiliano; Guerriero, Erica; Fiocco, Marco; Alberti, Ruggero; Polloni, Laura; Behnam, Ashkan; Carrion, Enrique A.; Pop, Eric; Sordan, Roman

    2015-04-01

    The influence of transistor size reduction (scaling) on the speed of realistic multi-stage integrated circuits (ICs) represents the main performance metric of a given transistor technology. Despite extensive interest in graphene electronics, scaling efforts have so far focused on individual transistors rather than multi-stage ICs. Here we study the scaling of graphene ICs based on transistors from 3.3 to 0.5 μm gate lengths and with different channel widths, access lengths, and lead thicknesses. The shortest gate delay of 31 ps per stage was obtained in sub-micron graphene ROs oscillating at 4.3 GHz, which is the highest oscillation frequency obtained in any strictly low-dimensional material to date. We also derived the fundamental Johnson limit, showing that scaled graphene ICs could be used at high frequencies in applications with small voltage swing.The influence of transistor size reduction (scaling) on the speed of realistic multi-stage integrated circuits (ICs) represents the main performance metric of a given transistor technology. Despite extensive interest in graphene electronics, scaling efforts have so far focused on individual transistors rather than multi-stage ICs. Here we study the scaling of graphene ICs based on transistors from 3.3 to 0.5 μm gate lengths and with different channel widths, access lengths, and lead thicknesses. The shortest gate delay of 31 ps per stage was obtained in sub-micron graphene ROs oscillating at 4.3 GHz, which is the highest oscillation frequency obtained in any strictly low-dimensional material to date. We also derived the fundamental Johnson limit, showing that scaled graphene ICs could be used at high frequencies in applications with small voltage swing. Electronic supplementary information (ESI) available: Discussions on the cutoff frequency fT, the maximum frequency of oscillation fmax, and the intrinsic gate delay CV/I. See DOI: 10.1039/c5nr01126d

  20. Cholinergic circuits in cognitive flexibility.

    PubMed

    Prado, Vania F; Janickova, Helena; Al-Onaizi, Mohammed A; Prado, Marco A M

    2017-03-14

    Cognitive flexibility, the ability to adjust behavior in response to new and unexpected conditions in the environment, is essential for adaptation to new challenges and survival. The cholinergic system is an important modulator of this complex behavior however, the exact cholinergic circuits involved in this modulation and the precise influence of acetylcholine (ACh) in the process is still not fully understood. Here we review the role of different cholinergic circuits in cognitive flexibility. Strong evidence indicates that cholinergic interneurons (CINs) from the dorsomedial striatum are essential for facilitating the establishment of a new selected strategy; an effect that seems to depend mainly on activation of muscarinic receptors. Cholinergic neurons from the nucleus basalis magnocellularis (nBM), which project to the prefrontal cortex, seem to modulate the initial inhibition of a previously learned strategy, however, this concept is still controversial. Additionally, some studies suggest that basal forebrain cholinergic neurons projecting to the hippocampus, basolateral amygdala, and posterior parietal cortex may also participate on the modulation of cognitive flexibility. We highlight the fact that when investigating effects of ACh on behavioral flexibility, or any other behavior, one has to keep in mind two important particularities of the cholinergic system: (1) Many cholinergic neurons in the brain co-release glutamate or GABA with ACh. Methodologies that rely on neuronal silencing or ablation lead to simultaneous elimination of both neurotransmitters, making interpretation of results complex. (2) The cholinergic gene locus has a unique organization, with the vesicular acetylcholine transporter (VAChT) gene present within the intron between the first and second exons of the choline acetyltransferase (ChAT) gene. Thus, behavioral studies using transgenic animals generated with ChAT bacterial artificial chromosome (BAC) clones should be considered