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Sample records for real time frequency

  1. Real-time, high frequency QRS electrocardiograph

    NASA Technical Reports Server (NTRS)

    Schlegel, Todd T. (Inventor); DePalma, Jude L. (Inventor); Moradi, Saeed (Inventor)

    2006-01-01

    Real time cardiac electrical data are received from a patient, manipulated to determine various useful aspects of the ECG signal, and displayed in real time in a useful form on a computer screen or monitor. The monitor displays the high frequency data from the QRS complex in units of microvolts, juxtaposed with a display of conventional ECG data in units of millivolts or microvolts. The high frequency data are analyzed for their root mean square (RMS) voltage values and the discrete RMS values and related parameters are displayed in real time. The high frequency data from the QRS complex are analyzed with imbedded algorithms to determine the presence or absence of reduced amplitude zones, referred to herein as RAZs. RAZs are displayed as go, no-go signals on the computer monitor. The RMS and related values of the high frequency components are displayed as time varying signals, and the presence or absence of RAZs may be similarly displayed over time.

  2. Real-Time, High-Frequency QRS Electrocardiograph

    NASA Technical Reports Server (NTRS)

    Schlegel, Todd T.; DePalma, Jude L.; Moradi, Saeed

    2003-01-01

    An electronic system that performs real-time analysis of the low-amplitude, high-frequency, ordinarily invisible components of the QRS portion of an electrocardiographic signal in real time has been developed. Whereas the signals readily visible on a conventional electrocardiogram (ECG) have amplitudes of the order of a millivolt and are characterized by frequencies <100 Hz, the ordinarily invisible components have amplitudes in the microvolt range and are characterized by frequencies from about 150 to about 250 Hz. Deviations of these high-frequency components from a normal pattern can be indicative of myocardial ischemia or myocardial infarction

  3. Real-Time Parameter Estimation in the Frequency Domain

    NASA Technical Reports Server (NTRS)

    Morelli, Eugene A.

    1999-01-01

    A method for real-time estimation of parameters in a linear dynamic state space model was developed and studied. The application is aircraft dynamic model parameter estimation from measured data in flight for indirect adaptive or reconfigurable control. Equation error in the frequency domain was used with a recursive Fourier transform for the real-time data analysis. Linear and nonlinear simulation examples and flight test data from the F-18 High Alpha Research Vehicle HARV) were used to demonstrate that the technique produces accurate model parameter estimates with appropriate error bounds. Parameter estimates converged in less than 1 cycle of the dominant dynamic mode natural frequencies, using control surface inputs measured in flight during ordinary piloted maneuvers. The real-time parameter estimation method has low computational requirements, and could be implemented aboard an aircraft in real time.

  4. Real-Time Parameter Estimation in the Frequency Domain

    NASA Technical Reports Server (NTRS)

    Morelli, Eugene A.

    2000-01-01

    A method for real-time estimation of parameters in a linear dynamic state-space model was developed and studied. The application is aircraft dynamic model parameter estimation from measured data in flight. Equation error in the frequency domain was used with a recursive Fourier transform for the real-time data analysis. Linear and nonlinear simulation examples and flight test data from the F-18 High Alpha Research Vehicle were used to demonstrate that the technique produces accurate model parameter estimates with appropriate error bounds. Parameter estimates converged in less than one cycle of the dominant dynamic mode, using no a priori information, with control surface inputs measured in flight during ordinary piloted maneuvers. The real-time parameter estimation method has low computational requirements and could be implemented

  5. Aircraft Fault Detection Using Real-Time Frequency Response Estimation

    NASA Technical Reports Server (NTRS)

    Grauer, Jared A.

    2016-01-01

    A real-time method for estimating time-varying aircraft frequency responses from input and output measurements was demonstrated. The Bat-4 subscale airplane was used with NASA Langley Research Center's AirSTAR unmanned aerial flight test facility to conduct flight tests and collect data for dynamic modeling. Orthogonal phase-optimized multisine inputs, summed with pilot stick and pedal inputs, were used to excite the responses. The aircraft was tested in its normal configuration and with emulated failures, which included a stuck left ruddervator and an increased command path latency. No prior knowledge of a dynamic model was used or available for the estimation. The longitudinal short period dynamics were investigated in this work. Time-varying frequency responses and stability margins were tracked well using a 20 second sliding window of data, as compared to a post-flight analysis using output error parameter estimation and a low-order equivalent system model. This method could be used in a real-time fault detection system, or for other applications of dynamic modeling such as real-time verification of stability margins during envelope expansion tests.

  6. Real-time background suppression during frequency domain lifetime measurements.

    PubMed

    Herman, Petr; Maliwal, Badri P; Lakowicz, Joseph R; Maliwal, Baldri P

    2002-10-01

    We describe real time background suppression of autofluorescence from biological samples during frequency domain or phase modulation measurements of intensity decays. For these measurements the samples were excited with a train of light pulses with widths below 1 ps. The detector was gated off for a short time period of 10 to 40 ns during and shortly after the excitation pulse. The reference signal needed for the frequency domain measurement was provided by a long-lifetime reference fluorophore which continues to emit following the off-gating pulse. Both the sample and the reference were measured under identical optical and electronic conditions avoiding the need for correction of the photomultiplier tube signal for the gating sequence. We demonstrate frequency domain background suppression using a mixture of short- and long-lifetime probes and for a long-lifetime probe in human plasma with significant autofluorescence. PMID:12381357

  7. Real time frequency domain fibreoptic temperature sensor using ruby crystals.

    PubMed

    Alcala, J R; Liao, S C; Zheng, J

    1996-01-01

    The excited state phosphorescence lifetime of ruby crystals is used to monitor temperature in the physiological range from 15 degrees to 45 degrees C with precision and accuracy less than 1 degree C, in real time. Precision of 0.1 degree C is attained with 3 min integration times. A 500 micron cubic ruby crystal bounded to the distal end of an optical fibre of similar core dimensions is excited with pulsed Ne-He laser light of about 9 microW average power. The instrument uses a sampler for data acquisition, and frequency domain methods for data fitting. The instrument amplifies the a.c. components of the detector output and band limits the signal to 800 Hz. The fundamental frequency of the excitation is set to 24.41 Hz to obtain 32 or less harmonics. This band-limited signal is sampled and averaged between 20 and 100 cycles to obtain temperature measurements in real time. The frequency domain representation of the data is obtained by employing fast Fourier transform algorithms. The phase delay and the modulation ratio, of each sampled harmonic, is then computed. Five to 32 values of the phase and modulation are averaged before computing the sensor lifetime. The technique is capable of measuring precise and accurate excited state lifetimes from subpicowatt luminescent signals in plastic optical fibres. A least squares fit yields the lifetimes of single exponentials. A component of zero lifetime is introduced to account for the backscatter excitation seen by the photodetector leaking through optical interference filters. The phosphorescence lifetimes measured reproducibly to about six parts in 1000, with a 2 s integration time, are used to monitor physiological temperature. Temperatures are computed employing empirical polynomials. The system drift is 3% over 5 h of continuous operation. The instrumentation and methods allow 2.7 s update times and 50 s full response times. PMID:8771039

  8. Real-time FPGA architectures for space-time frequency-planar MDSP

    NASA Astrophysics Data System (ADS)

    Madanayake, Arjuna

    In recent times, a variety of applications have emerged for real-time VLSI multidimensional digital filters, of which many draw upon broadband plane-wave filtering for array-based beam-forming and the processing of image sequences in video signals. This thesis describes recent progress with real-time hardware architectures for spatio-temporal multidimensional digital filters. The frequency-planar filter is a fundamental building block for many useful multidimensional digital filters including linear trajectory filters and plane-wave filters having beam, fan and cone shaped passbands. The proposed architectures for implementing the abovementioned frequency-planar building blocks can be broadly classified as systolic-array architectures and raster scanned architectures. The systolic-array architectures employ massively-parallel structures for very high throughput signal processing, with typical applications in RF beam-forming for wireless communications, microwave imaging, radar, radio astronomy, and navigation. The scanned-array structures have very low circuit complexity compared to systolic-arrays. However, the real-time throughput levels are correspondingly lower, and therefore, these architectures are most suited for slower applications such as ultrasonic imaging, digital video, sonar, and directional audio. A novel multidimensional look-ahead based speed optimization method is proposed for increasing the real-time computational throughput of the architectures. Furthermore, the 2D/3D frequency-planar filters, which conventionally require sampled linear and rectangular sensor arrays, have been extended to curvilinear coordinate systems using circular and toroidal sensor arrays, leading to applications such as the highly-selective directional enhancement of concentric broadband spiral-waves and the directional enhancement of linear flows on the surface of a torus. Prototype FPGA circuit implementations are provided for the proposed systolic-array processors

  9. Real-time, high frequency QRS electrocardiograph with reduced amplitude zone detection

    NASA Technical Reports Server (NTRS)

    Schlegel, Todd T. (Inventor); DePalma, Jude L. (Inventor); Moradi, Saeed (Inventor)

    2009-01-01

    Real time cardiac electrical data are received from a patient, manipulated to determine various useful aspects of the ECG signal, and displayed in real time in a useful form on a computer screen or monitor. The monitor displays the high frequency data from the QRS complex in units of microvolts, juxtaposed with a display of conventional ECG data in units of millivolts or microvolts. The high frequency data are analyzed for their root mean square (RMS) voltage values and the discrete RMS values and related parameters are displayed in real time. The high frequency data from the QRS complex are analyzed with imbedded algorithms to determine the presence or absence of reduced amplitude zones, referred to herein as ''RAZs''. RAZs are displayed as ''go, no-go'' signals on the computer monitor. The RMS and related values of the high frequency components are displayed as time varying signals, and the presence or absence of RAZs may be similarly displayed over time.

  10. Real-Time Distributed Embedded Oscillator Operating Frequency Monitoring

    NASA Technical Reports Server (NTRS)

    Pollock, Julie; Oliver, Brett; Brickner, Christopher

    2012-01-01

    A document discusses the utilization of embedded clocks inside of operating network data links as an auxiliary clock source to satisfy local oscillator monitoring requirements. Modem network interfaces, typically serial network links, often contain embedded clocking information of very tight precision to recover data from the link. This embedded clocking data can be utilized by the receiving device to monitor the local oscillator for tolerance to required specifications, often important in high-integrity fault-tolerant applications. A device can utilize a received embedded clock to determine if the local or the remote device is out of tolerance by using a single link. The local device can determine if it is failing, assuming a single fault model, with two or more active links. Network fabric components, containing many operational links, can potentially determine faulty remote or local devices in the presence of multiple faults. Two methods of implementation are described. In one method, a recovered clock can be directly used to monitor the local clock as a direct replacement of an external local oscillator. This scheme is consistent with a general clock monitoring function whereby clock sources are clocking two counters and compared over a fixed interval of time. In another method, overflow/underflow conditions can be used to detect clock relationships for monitoring. These network interfaces often provide clock compensation circuitry to allow data to be transferred from the received (network) clock domain to the internal clock domain. This circuit could be modified to detect overflow/underflow conditions of the buffering required and report a fast or slow receive clock, respectively.

  11. A method for efficient fractional sample delay generation for real-time frequency-domain beamformers

    SciTech Connect

    Breeding, J.E.; Karnowski, T.P.

    1995-07-01

    This paper presents an efficient method for fractional delay filter generation for frequency-domain beamformers. A common misunderstanding regarding frequency-domain beamforming is that any fractional time shift can be achieved using the delay property of the discrete Fourier transform (DFT). Blind application of the DFT delay property introduces circular convolution errors that may adversely affect the beam`s time series. The method presented avoids these errors while enabling real-time processing.

  12. Real-time volcano monitoring using GNSS single-frequency receivers

    NASA Astrophysics Data System (ADS)

    Lee, Seung-Woo; Yun, Sung-Hyo; Kim, Do Hyeong; Lee, Dukkee; Lee, Young J.; Schutz, Bob E.

    2015-12-01

    We present a real-time volcano monitoring strategy that uses the Global Navigation Satellite System (GNSS), and we examine the performance of the strategy by processing simulated and real data and comparing the results with published solutions. The cost of implementing the strategy is reduced greatly by using single-frequency GNSS receivers except for one dual-frequency receiver that serves as a base receiver. Positions of the single-frequency receivers are computed relative to the base receiver on an epoch-by-epoch basis using the high-rate double-difference (DD) GNSS technique, while the position of the base station is fixed to the values obtained with a deferred-time precise point positioning technique and updated on a regular basis. Since the performance of the single-frequency high-rate DD technique depends on the conditions of the ionosphere over the monitoring area, the ionospheric total electron content is monitored using the dual-frequency data from the base receiver. The surface deformation obtained with the high-rate DD technique is eventually processed by a real-time inversion filter based on the Mogi point source model. The performance of the real-time volcano monitoring strategy is assessed through a set of tests and case studies, in which the data recorded during the 2007 eruption of Kilauea and the 2005 eruption of Augustine are processed in a simulated real-time mode. The case studies show that the displacement time series obtained with the strategy seem to agree with those obtained with deferred-time, dual-frequency approaches at the level of 10-15 mm. Differences in the estimated volume change of the Mogi source between the real-time inversion filter and previously reported works were in the range of 11 to 13% of the maximum volume changes of the cases examined.

  13. Multiple Input Design for Real-Time Parameter Estimation in the Frequency Domain

    NASA Technical Reports Server (NTRS)

    Morelli, Eugene

    2003-01-01

    A method for designing multiple inputs for real-time dynamic system identification in the frequency domain was developed and demonstrated. The designed inputs are mutually orthogonal in both the time and frequency domains, with reduced peak factors to provide good information content for relatively small amplitude excursions. The inputs are designed for selected frequency ranges, and therefore do not require a priori models. The experiment design approach was applied to identify linear dynamic models for the F-15 ACTIVE aircraft, which has multiple control effectors.

  14. Crash Frequency Modeling Using Real-Time Environmental and Traffic Data and Unbalanced Panel Data Models

    PubMed Central

    Chen, Feng; Chen, Suren; Ma, Xiaoxiang

    2016-01-01

    Traffic and environmental conditions (e.g., weather conditions), which frequently change with time, have a significant impact on crash occurrence. Traditional crash frequency models with large temporal scales and aggregated variables are not sufficient to capture the time-varying nature of driving environmental factors, causing significant loss of critical information on crash frequency modeling. This paper aims at developing crash frequency models with refined temporal scales for complex driving environments, with such an effort providing more detailed and accurate crash risk information which can allow for more effective and proactive traffic management and law enforcement intervention. Zero-inflated, negative binomial (ZINB) models with site-specific random effects are developed with unbalanced panel data to analyze hourly crash frequency on highway segments. The real-time driving environment information, including traffic, weather and road surface condition data, sourced primarily from the Road Weather Information System, is incorporated into the models along with site-specific road characteristics. The estimation results of unbalanced panel data ZINB models suggest there are a number of factors influencing crash frequency, including time-varying factors (e.g., visibility and hourly traffic volume) and site-varying factors (e.g., speed limit). The study confirms the unique significance of the real-time weather, road surface condition and traffic data to crash frequency modeling. PMID:27322306

  15. Crash Frequency Modeling Using Real-Time Environmental and Traffic Data and Unbalanced Panel Data Models.

    PubMed

    Chen, Feng; Chen, Suren; Ma, Xiaoxiang

    2016-01-01

    Traffic and environmental conditions (e.g., weather conditions), which frequently change with time, have a significant impact on crash occurrence. Traditional crash frequency models with large temporal scales and aggregated variables are not sufficient to capture the time-varying nature of driving environmental factors, causing significant loss of critical information on crash frequency modeling. This paper aims at developing crash frequency models with refined temporal scales for complex driving environments, with such an effort providing more detailed and accurate crash risk information which can allow for more effective and proactive traffic management and law enforcement intervention. Zero-inflated, negative binomial (ZINB) models with site-specific random effects are developed with unbalanced panel data to analyze hourly crash frequency on highway segments. The real-time driving environment information, including traffic, weather and road surface condition data, sourced primarily from the Road Weather Information System, is incorporated into the models along with site-specific road characteristics. The estimation results of unbalanced panel data ZINB models suggest there are a number of factors influencing crash frequency, including time-varying factors (e.g., visibility and hourly traffic volume) and site-varying factors (e.g., speed limit). The study confirms the unique significance of the real-time weather, road surface condition and traffic data to crash frequency modeling. PMID:27322306

  16. Real-Time Single Frequency Precise Point Positioning Using SBAS Corrections.

    PubMed

    Li, Liang; Jia, Chun; Zhao, Lin; Cheng, Jianhua; Liu, Jianxu; Ding, Jicheng

    2016-01-01

    Real-time single frequency precise point positioning (PPP) is a promising technique for high-precision navigation with sub-meter or even centimeter-level accuracy because of its convenience and low cost. The navigation performance of single frequency PPP heavily depends on the real-time availability and quality of correction products for satellite orbits and satellite clocks. Satellite-based augmentation system (SBAS) provides the correction products in real-time, but they are intended to be used for wide area differential positioning at 1 meter level precision. By imposing the constraints for ionosphere error, we have developed a real-time single frequency PPP method by sufficiently utilizing SBAS correction products. The proposed PPP method are tested with static and kinematic data, respectively. The static experimental results show that the position accuracy of the proposed PPP method can reach decimeter level, and achieve an improvement of at least 30% when compared with the traditional SBAS method. The positioning convergence of the proposed PPP method can be achieved in 636 epochs at most in static mode. In the kinematic experiment, the position accuracy of the proposed PPP method can be improved by at least 20 cm relative to the SBAS method. Furthermore, it has revealed that the proposed PPP method can achieve decimeter level convergence within 500 s in the kinematic mode. PMID:27517930

  17. On the implementation of a real-time information security architecture in frequency domain

    NASA Astrophysics Data System (ADS)

    Basu, Abhishek; Sarkar, Souvik; Sarkar, Subir Kumar

    2015-12-01

    This paper presents the real-time implementation of a watermarking-based information security architecture in frequency domain. The scheme emphasises on the human visual system (HVS)-supported watermarking approach using wavelet-lifting technique. In addition to HVS, image registration algorithm is also introduced in order to increase the resiliency as well as the security of the estimated recovered watermark image. The algorithmic steps with optimisation considerations about the real-time implementation on TMS320CDSK6416/6713 fixed/floating point digital signal processor are also projected.

  18. Real-time open-loop frequency response analysis of flight test data

    NASA Technical Reports Server (NTRS)

    Bosworth, J. T.; West, J. C.

    1986-01-01

    A technique has been developed to compare the open-loop frequency response of a flight test aircraft real time with linear analysis predictions. The result is direct feedback to the flight control systems engineer on the validity of predictions and adds confidence for proceeding with envelope expansion. Further, gain and phase margins can be tracked for trends in a manner similar to the techniques used by structural dynamics engineers in tracking structural modal damping.

  19. A Real-Time Smart Sensor for High-Resolution Frequency Estimation in Power Systems

    PubMed Central

    Granados-Lieberman, David; Romero-Troncoso, Rene J.; Cabal-Yepez, Eduardo; Osornio-Rios, Roque A.; Franco-Gasca, Luis A.

    2009-01-01

    Power quality monitoring is a theme in vogue and accurate frequency measurement of the power line is a major issue. This problem is particularly relevant for power generating systems since the generated signal must comply with restrictive standards. The novelty of this work is the development of a smart sensor for real-time high-resolution frequency measurement in accordance with international standards for power quality monitoring. The proposed smart sensor utilizes commercially available current clamp, hall-effect sensor or resistor as primary sensor. The signal processing is carried out through the chirp z-transform. Simulations and experimental results show the efficiency of the proposed smart sensor. PMID:22400002

  20. Real-time locating and speed measurement of fibre fuse using optical frequency-domain reflectometry.

    PubMed

    Jiang, Shoulin; Ma, Lin; Fan, Xinyu; Wang, Bin; He, Zuyuan

    2016-01-01

    We propose and experimentally demonstrate real-time locating and speed measurement of fibre fuse by analysing the Doppler shift of reflected light using optical frequency-domain reflectometry (OFDR). Our method can detect the start of a fibre fuse within 200 ms which is equivalent to a propagation distance of about 10 cm in standard single-mode fibre. We successfully measured instantaneous speed of propagating fibre fuses and observed their subtle fluctuation owing to the laser power instability. The resolution achieved for speed measurement in our demonstration is 1 × 10(-3) m/s. We studied the fibre fuse propagation speed dependence on the launched power in different fibres. Our method is promising for both real time fibre fuse monitoring and future studies on its propagation and termination. PMID:27146550

  1. Real-time locating and speed measurement of fibre fuse using optical frequency-domain reflectometry

    NASA Astrophysics Data System (ADS)

    Jiang, Shoulin; Ma, Lin; Fan, Xinyu; Wang, Bin; He, Zuyuan

    2016-05-01

    We propose and experimentally demonstrate real-time locating and speed measurement of fibre fuse by analysing the Doppler shift of reflected light using optical frequency-domain reflectometry (OFDR). Our method can detect the start of a fibre fuse within 200 ms which is equivalent to a propagation distance of about 10 cm in standard single-mode fibre. We successfully measured instantaneous speed of propagating fibre fuses and observed their subtle fluctuation owing to the laser power instability. The resolution achieved for speed measurement in our demonstration is 1 × 10‑3 m/s. We studied the fibre fuse propagation speed dependence on the launched power in different fibres. Our method is promising for both real time fibre fuse monitoring and future studies on its propagation and termination.

  2. Real-time locating and speed measurement of fibre fuse using optical frequency-domain reflectometry

    PubMed Central

    Jiang, Shoulin; Ma, Lin; Fan, Xinyu; Wang, Bin; He, Zuyuan

    2016-01-01

    We propose and experimentally demonstrate real-time locating and speed measurement of fibre fuse by analysing the Doppler shift of reflected light using optical frequency-domain reflectometry (OFDR). Our method can detect the start of a fibre fuse within 200 ms which is equivalent to a propagation distance of about 10 cm in standard single-mode fibre. We successfully measured instantaneous speed of propagating fibre fuses and observed their subtle fluctuation owing to the laser power instability. The resolution achieved for speed measurement in our demonstration is 1 × 10−3 m/s. We studied the fibre fuse propagation speed dependence on the launched power in different fibres. Our method is promising for both real time fibre fuse monitoring and future studies on its propagation and termination. PMID:27146550

  3. A new system for measurement of low frequency radio transmitting antenna parameters in near real time

    NASA Astrophysics Data System (ADS)

    Tietsworth, S. C.

    1991-06-01

    Fixed site very low frequency (VLF) and low frequency (LF) transmit antenna systems are used as the primary means of communication to submarine at sea. Until now there has not been a system to measure important antenna parameters on these low frequency transmit antennas in near real time while the antenna is being driven by frequency shift modulation. This paper describes a new system which can be used to measure several important antenna and tuning system parameters on these transmit antennas while the antennas are in normal operation. The measurements are made by sampling and processing the antenna voltage and current signals to calculate the antenna system resistance, capacitance, inductance, voltage, current and power which can then be displayed and stored on a personal computer. All of these measurements are made while the antenna is being driven by FSK or MSK signals. The paper includes a model of a typical low frequency transmit antenna as well as the associated equations. The response of the antenna system to frequency shift keying signals is then presented. In addition, the algorithms, hardware, and software used by the measurement system, called the VLF/LF antenna monitor system (AMOS), are discussed along with a summary of results obtained during initial testing of the AMOS system.

  4. Radiance transfer biclustering for real-time all-frequency biscale rendering.

    PubMed

    Sun, Xin; Hou, Qiming; Ren, Zhong; Zhou, Kun; Guo, Baining

    2011-01-01

    We present a real-time algorithm to render all-frequency radiance transfer at both macroscale and mesoscale. At a mesoscale, the shading is computed on a per-pixel basis by integrating the product of the local incident radiance and a bidirectional texture function. While at a macroscale, the precomputed transfer matrix, which transfers the global incident radiance to the local incident radiance at each vertex, is losslessly compressed by a novel biclustering technique. The biclustering is directly applied on the radiance transfer represented in a pixel basis, on which the BTF is naturally defined. It exploits the coherence in the transfer matrix and a property of matrix element values to reduce both storage and runtime computation cost. Our new algorithm renders at real-time frame rates realistic materials and shadows under all-frequency direct environment lighting. Comparisons show that our algorithm is able to generate images that compare favorably with reference ray tracing results, and has obvious advantages over alternative methods in storage and preprocessing time. PMID:20421683

  5. Real-time seismic intensity prediction using frequency-dependent site amplification factors

    NASA Astrophysics Data System (ADS)

    Ogiso, Masashi; Aoki, Shigeki; Hoshiba, Mitsuyuki

    2016-05-01

    A promising approach for the next generation of earthquake early warning system is based on predicting ground motion directly from observed ground motion, without any information of hypocenter. In this study, we predicted seismic intensity at the target stations from the observed ground motion at adjacent stations, employing two different methods of correction for site amplification factors. The first method was frequency-dependent correction prediction, in which we used a digital causal filter to correct the site amplification for the observed waveform in the time domain. The second method was scalar correction, in which we used average differences in seismic intensity between two stations for the site amplification correction. Results from thousands of station pairs that covered almost all of Japan showed that seismic intensity prediction with frequency-dependent correction prediction was more accurate than prediction with scalar correction. Frequency-dependent correction for site amplification in the time domain may lead to more accurate prediction of ground motion in real time.

  6. Real-Time Time-Frequency Two-Dimensional Imaging of Ultrafast Transient Signals in Solid-State Organic Materials

    PubMed Central

    Takeda, Jun; Ishida, Akihiro; Makishima, Yoshinori; Katayama, Ikufumi

    2010-01-01

    In this review, we demonstrate a real-time time-frequency two-dimensional (2D) pump-probe imaging spectroscopy implemented on a single shot basis applicable to excited-state dynamics in solid-state organic and biological materials. Using this technique, we could successfully map ultrafast time-frequency 2D transient absorption signals of β-carotene in solid films with wide temporal and spectral ranges having very short accumulation time of 20 ms per unit frame. The results obtained indicate the high potential of this technique as a powerful and unique spectroscopic tool to observe ultrafast excited-state dynamics of organic and biological materials in solid-state, which undergo rapid photodegradation. PMID:22399879

  7. Real-time control of ELM and sawtooth frequencies: similarities and differences

    NASA Astrophysics Data System (ADS)

    Lennholm, M.; Frigione, D.; Graves, J. P.; Beaumont, P. S.; Blackman, T.; Carvalho, I. S.; Chapman, I.; Dumont, R.; Felton, R.; Garzotti, L.; Goniche, M.; Goodyear, A.; Grist, D.; Jachmich, S.; Johnson, T.; Lang, P.; Lerche, E.; de la Luna, E.; Monakhov, I.; Mooney, R.; Morris, J.; Nave, M. F. F.; Reich, M.; Rimini, F.; Sips, G.; Sheikh, H.; Sozzi, C.; Tsalas, M.; Contributors, JET

    2016-01-01

    ELMs and Sawteeth, located in different parts of the plasma, are similar from a control engineering point of view. Both manifest themselves through quiescent periods interrupted by periodic collapses. For both, large collapses, following long quiescent periods, have detrimental effects while short periods are associated with decreased confinement. Following the installation of the all metal ‘ITER like wall’ on JET, sawteeth and ELMs also play an important role by expelling tungsten from the core and edge of the plasma respectively. Control of tungsten has therefore been added to divertor heat load reduction, NTM avoidance and helium ash removal as reasons for requiring ELM and sawtooth control. It is therefore of interest to implement control systems to maintain the sawtooth and ELM frequencies in the desired ranges. On JET, ELM frequency control uses radial field ‘kicks’ and pellet and gas injection as actuators, while sawtooth control uses ion cyclotron resonance heating (ICRH). JET experiments have, for the first time, established feedback control of the ELM frequency, via real time variation of the injected gas flow [1]. Using this controller in conjunction with pellet injection allows the ELM frequency to be kept as required despite variations in pellet ELM triggering efficiency. JET Sawtooth control experiments have, for the first time, demonstrated that low field side ICRH, as foreseen for ITER, can shorten sawteeth lengthened by central fast ions [2]. The development of ELM and sawtooth control could be key to achieve stable high performance JET discharges with minimal tungsten content. Integrating such schemes into an overall control strategy will be required in future tokamaks and gaining experience on current tokamaks is essential.

  8. High-speed camera with real time processing for frequency domain imaging

    PubMed Central

    Shia, Victor; Watt, David; Faris, Gregory W.

    2011-01-01

    We describe a high-speed camera system for frequency domain imaging suitable for applications such as in vivo diffuse optical imaging and fluorescence lifetime imaging. 14-bit images are acquired at 2 gigapixels per second and analyzed with real-time pipeline processing using field programmable gate arrays (FPGAs). Performance of the camera system has been tested both for RF-modulated laser imaging in combination with a gain-modulated image intensifier and a simpler system based upon an LED light source. System amplitude and phase noise are measured and compared against theoretical expressions in the shot noise limit presented for different frequency domain configurations. We show the camera itself is capable of shot noise limited performance for amplitude and phase in as little as 3 ms, and when used in combination with the intensifier the noise levels are nearly shot noise limited. The best phase noise in a single pixel is 0.04 degrees for a 1 s integration time. PMID:21750770

  9. Real-time single-frequency GPS/MEMS-IMU attitude determination of lightweight UAVs.

    PubMed

    Eling, Christian; Klingbeil, Lasse; Kuhlmann, Heiner

    2015-01-01

    In this paper, a newly-developed direct georeferencing system for the guidance, navigation and control of lightweight unmanned aerial vehicles (UAVs), having a weight limit of 5 kg and a size limit of 1.5 m, and for UAV-based surveying and remote sensing applications is presented. The system is intended to provide highly accurate positions and attitudes (better than 5 cm and 0.5°) in real time, using lightweight components. The main focus of this paper is on the attitude determination with the system. This attitude determination is based on an onboard single-frequency GPS baseline, MEMS (micro-electro-mechanical systems) inertial sensor readings, magnetic field observations and a 3D position measurement. All of this information is integrated in a sixteen-state error space Kalman filter. Special attention in the algorithm development is paid to the carrier phase ambiguity resolution of the single-frequency GPS baseline observations. We aim at a reliable and instantaneous ambiguity resolution, since the system is used in urban areas, where frequent losses of the GPS signal lock occur and the GPS measurement conditions are challenging. Flight tests and a comparison to a navigation-grade inertial navigation system illustrate the performance of the developed system in dynamic situations. Evaluations show that the accuracies of the system are 0.05° for the roll and the pitch angle and 0.2° for the yaw angle. The ambiguities of the single-frequency GPS baseline can be resolved instantaneously in more than 90% of the cases. PMID:26501281

  10. Real-Time Single-Frequency GPS/MEMS-IMU Attitude Determination of Lightweight UAVs

    PubMed Central

    Eling, Christian; Klingbeil, Lasse; Kuhlmann, Heiner

    2015-01-01

    In this paper, a newly-developed direct georeferencing system for the guidance, navigation and control of lightweight unmanned aerial vehicles (UAVs), having a weight limit of 5 kg and a size limit of 1.5 m, and for UAV-based surveying and remote sensing applications is presented. The system is intended to provide highly accurate positions and attitudes (better than 5 cm and 0.5∘) in real time, using lightweight components. The main focus of this paper is on the attitude determination with the system. This attitude determination is based on an onboard single-frequency GPS baseline, MEMS (micro-electro-mechanical systems) inertial sensor readings, magnetic field observations and a 3D position measurement. All of this information is integrated in a sixteen-state error space Kalman filter. Special attention in the algorithm development is paid to the carrier phase ambiguity resolution of the single-frequency GPS baseline observations. We aim at a reliable and instantaneous ambiguity resolution, since the system is used in urban areas, where frequent losses of the GPS signal lock occur and the GPS measurement conditions are challenging. Flight tests and a comparison to a navigation-grade inertial navigation system illustrate the performance of the developed system in dynamic situations. Evaluations show that the accuracies of the system are 0.05∘ for the roll and the pitch angle and 0.2∘ for the yaw angle. The ambiguities of the single-frequency GPS baseline can be resolved instantaneously in more than 90% of the cases. PMID:26501281

  11. A frequency response analysis approach for quantitative assessment of actuator tracking for real-time hybrid simulation

    NASA Astrophysics Data System (ADS)

    Guo, Tong; Chen, Cheng; Xu, WeiJie; Sanchez, Frank

    2014-04-01

    Real-time hybrid simulation is a viable and economical technique that allows researchers to observe the behavior of critical elements at full scale when an entire structure is subjected to dynamic loading. To ensure reliable experimental results, it is necessary to evaluate the actuator tracking after the test, even when sophisticated compensation methods are used to negate the detrimental effect of servo-hydraulic dynamics. Existing methods for assessment of actuator tracking are often based on time-domain analysis. This paper proposes a frequency-domain-based approach to the assessment of actuator tracking for real-time hybrid simulations. To ensure the accuracy of the proposed frequency response approach, the effects of spectrum leakage are investigated as well as the length and sampling frequency requirements of the signals. Two signal pre-processing techniques (data segmentation and window transform) are also discussed and compared to improve the accuracy of the proposed approach. Finally the effectiveness of the proposed frequency-domain-based approach is demonstrated through both computational analyses and laboratory tests, including real-time tests with predefined displacement and real-time hybrid simulation.

  12. Real-Time Frequency Response Estimation Using Joined-Wing SensorCraft Aeroelastic Wind-Tunnel Data

    NASA Technical Reports Server (NTRS)

    Grauer, Jared A; Heeg, Jennifer; Morelli, Eugene A

    2012-01-01

    A new method is presented for estimating frequency responses and their uncertainties from wind-tunnel data in real time. The method uses orthogonal phase-optimized multi- sine excitation inputs and a recursive Fourier transform with a least-squares estimator. The method was first demonstrated with an F-16 nonlinear flight simulation and results showed that accurate short period frequency responses were obtained within 10 seconds. The method was then applied to wind-tunnel data from a previous aeroelastic test of the Joined- Wing SensorCraft. Frequency responses describing bending strains from simultaneous control surface excitations were estimated in a time-efficient manner.

  13. Real time observation of low frequency heme protein vibrations using femtosecond coherence spectroscopy

    NASA Astrophysics Data System (ADS)

    Zhu, L.; Li, P.; Huang, M.; Sage, J. T.; Champion, P. M.

    1994-01-01

    Femtosecond laser pulses, resonant with the Soret bands of myoglobin (Mb) and cytochrome c, are used to probe coherent low frequency nuclear motion of the heme group. The time domain analysis is in good agreement with frequencies obtained independently using spontaneous resonance Raman spectroscopy. The deoxyMb data reveal a strong oscillation near 300 fs (~ 100 cm-1) and a persistent feature also appears near 50 cm-1. This is near the frequency expected for heme doming motion, which has been associated with the ligand binding reaction coordinate of Mb.

  14. Carrier-Doppler-based real-time two way satellite frequency transfer and its application in BeiDou system

    NASA Astrophysics Data System (ADS)

    Liu, Zengjun; Gong, Hang; Yang, Wenke; Zhu, Xiangwei; Ou, Gang

    2014-09-01

    Two-way satellite time and frequency transfer (TWSTFT) method is valuable for precise time and frequency transfer. The frequency could be directly transferred by utilizing two-way carrier Doppler measurement. This method requires each station observing both its own and associated station’s transponder signals transferred by satellite. In BeiDou system (BDS), the reference station and the field station construct a two-way link via a GEO satellite, and the field station sends pseudorange and carrier phase information to the reference station by transmission signal, in order to achieve real time TWSTFT. This paper analyzes the theory of carrier Doppler based TWSTFT (called CD-TWSTFT), and validates it by using on line data of BDS. The results demonstrated that the performance of CD TWSTFT is much better than code based TWSTFT in short-term frequency transfer and almost same at long-term frequency transfer.

  15. Retrieving real-time precise co-seismic displacements with a standalone single-frequency GPS receiver

    NASA Astrophysics Data System (ADS)

    Chen, Kejie; Ge, Maorong; Li, Xingxing; Babeyko, Andrey; Ramatschi, Markus; Bradke, Markus

    2015-08-01

    Nowadays, Global Positioning System (GPS) plays an increasingly important role in retrieving real-time precise co-seismic displacements for geo-hazard monitoring and early warning. Several real-time positioning approaches have been demonstrated for such purpose, such as real-time kinematic relative positioning, precise point positioning, etc., where dual-frequency geodetic receivers are applied for the removal of ionosphere delays by inter-frequency combination. At the same time, it would be also useful to develop efficient algorithms for estimating precise displacements with low-cost GPS receivers since they can make a denser network or multi-sensors combination without putting too much financial burden. In this contribution, we present a new method to retrieve precise co-seismic displacements in real-time using a standalone single-frequency receiver. In the new method, observations prior to an earthquake are utilized to establish a precise ionospheric delay prediction model, so that precise co-seismic displacements can be obtained without any convergence process. Our method was validated with an outdoor experiment as well as by re-processing of 1-Hz GPS data collected by the GEONET network during the 2011 Tohoku Mw 9.0 earthquake. For the latter, RMS against dual-frequency receivers constituted 2 cm for horizontal components and 3 cm for the vertical component. We specially address the observation biases and their impact on the accuracy of single frequency positioning. Our approach makes real-time GPS displacement monitoring with dense network much more affordable in terms of financial costs.

  16. Accuracy of Single Frequency GPS Observations Processing In Near Real-time With Use of Code Predicted Products

    NASA Astrophysics Data System (ADS)

    Wielgosz, P. A.

    In this year, the system of active geodetic GPS permanent stations is going to be estab- lished in Poland. This system should provide GPS observations for a wide spectrum of users, especially it will be a great opportunity for surveyors. Many of surveyors still use cheaper, single frequency receivers. This paper focuses on processing of single frequency GPS observations only. During processing of such observations the iono- sphere plays an important role, so we concentrated on the influence of the ionosphere on the positional coordinates. Twenty consecutive days of GPS data from 2001 year were processed to analyze the accuracy of a derived three-dimensional relative vec- tor position between GPS stations. Observations from two Polish EPN/IGS stations: BOGO and JOZE were used. In addition to, a new test station - IGIK was created. In this paper, the results of single frequency GPS observations processing in near real- time are presented. Baselines of 15, 27 and 42 kilometers and sessions of 1, 2, 3, 4, and 6 hours long were processed. While processing we used CODE (Centre for Orbit De- termination in Europe, Bern, Switzerland) predicted products: orbits and ionosphere info. These products are available in real-time and enable near real-time processing. Software Bernese v. 4.2 for Linux and BPE (Bernese Processing Engine) mode were used. These results are shown with a reference to dual frequency weekly solution (the best solution). Obtained GPS positional time and GPS baseline length dependency accuracy is presented for single frequency GPS observations.

  17. Real-time dynamic calibration of a tunable frequency laser source using a Fabry-Pérot interferometer.

    PubMed

    Mandula, Gábor; Kis, Zsolt; Lengyel, Krisztián

    2015-12-01

    We report on a method for real-time dynamic calibration of a tunable external cavity diode laser by using a partially mode-matched plano-concave Fabry-Pérot interferometer in reflection geometry. Wide range laser frequency scanning is carried out by piezo-driven tilting of a diffractive grating playing the role of a frequency selective mirror in the laser cavity. The grating tilting system has a considerable mechanical inertness, so static laser frequency calibration leads to false results. The proposed real-time dynamic calibration based on the identification of primary- and Gouy-effect type secondary interference peaks with known frequency and temporal history can be used for a wide scanning range (from 0.2 GHz to more than 1 GHz). A concave spherical mirror with a radius of R = 100 cm and a plain 1% transmitting mirror was used as a Fabry-Pérot interferometer with various resonator lengths to investigate and demonstrate real-time calibration procedures for two kinds of laser frequency scanning functions. PMID:26724003

  18. Real-time dynamic calibration of a tunable frequency laser source using a Fabry-Pérot interferometer

    SciTech Connect

    Mandula, Gábor Kis, Zsolt; Lengyel, Krisztián

    2015-12-15

    We report on a method for real-time dynamic calibration of a tunable external cavity diode laser by using a partially mode-matched plano-concave Fabry-Pérot interferometer in reflection geometry. Wide range laser frequency scanning is carried out by piezo-driven tilting of a diffractive grating playing the role of a frequency selective mirror in the laser cavity. The grating tilting system has a considerable mechanical inertness, so static laser frequency calibration leads to false results. The proposed real-time dynamic calibration based on the identification of primary- and Gouy-effect type secondary interference peaks with known frequency and temporal history can be used for a wide scanning range (from 0.2 GHz to more than 1 GHz). A concave spherical mirror with a radius of R = 100 cm and a plain 1% transmitting mirror was used as a Fabry-Pérot interferometer with various resonator lengths to investigate and demonstrate real-time calibration procedures for two kinds of laser frequency scanning functions.

  19. Real-Time Point Positioning Performance Evaluation of Single-Frequency Receivers Using NASA's Global Differential GPS System

    NASA Technical Reports Server (NTRS)

    Muellerschoen, Ronald J.; Iijima, Byron; Meyer, Robert; Bar-Sever, Yoaz; Accad, Elie

    2004-01-01

    This paper evaluates the performance of a single-frequency receiver using the 1-Hz differential corrections as provided by NASA's global differential GPS system. While the dual-frequency user has the ability to eliminate the ionosphere error by taking a linear combination of observables, the single-frequency user must remove or calibrate this error by other means. To remove the ionosphere error we take advantage of the fact that the magnitude of the group delay in range observable and the carrier phase advance have the same magnitude but are opposite in sign. A way to calibrate this error is to use a real-time database of grid points computed by JPL's RTI (Real-Time Ionosphere) software. In both cases we evaluate the positional accuracy of a kinematic carrier phase based point positioning method on a global extent.

  20. Real-Time 12-Lead High-Frequency QRS Electrocardiography for Enhanced Detection of Myocardial Ischemia and Coronary Artery Disease

    NASA Technical Reports Server (NTRS)

    Schlegel, Todd T.; Kulecz, Walter B.; DePalma, Jude L.; Feiveson, Alan H.; Wilson, John S.; Rahman, M. Atiar; Bungo, Michael W.

    2004-01-01

    Several studies have shown that diminution of the high-frequency (HF; 150-250 Hz) components present within the central portion of the QRS complex of an electrocardiogram (ECG) is a more sensitive indicator for the presence of myocardial ischemia than are changes in the ST segments of the conventional low-frequency ECG. However, until now, no device has been capable of displaying, in real time on a beat-to-beat basis, changes in these HF QRS ECG components in a continuously monitored patient. Although several software programs have been designed to acquire the HF components over the entire QRS interval, such programs have involved laborious off-line calculations and postprocessing, limiting their clinical utility. We describe a personal computer-based ECG software program developed recently at the National Aeronautics and Space Administration (NASA) that acquires, analyzes, and displays HF QRS components in each of the 12 conventional ECG leads in real time. The system also updates these signals and their related derived parameters in real time on a beat-to-beat basis for any chosen monitoring period and simultaneously displays the diagnostic information from the conventional (low-frequency) 12-lead ECG. The real-time NASA HF QRS ECG software is being evaluated currently in multiple clinical settings in North America. We describe its potential usefulness in the diagnosis of myocardial ischemia and coronary artery disease.

  1. Real-time implementation of frequency-modulated continuous-wave synthetic aperture radar imaging using field programmable gate array

    NASA Astrophysics Data System (ADS)

    Quan, Yinghui; Li, Yachao; Hu, Guibin; Xing, Mengdao

    2015-06-01

    A new miniature linear frequency-modulated continuous-wave radar which mounted on an unmanned aerial vehicle is presented. It allows the accomplishment of high resolution synthetic aperture radar imaging in real-time. Only a Kintex-7 field programmable gate array from Xilinx is utilized for whole signal processing of sophisticated radar imaging algorithms. The proposed hardware architecture achieves remarkable improvement in integration, power consumption, volume, and computing performance over its predecessor designs. The realized design is verified by flight campaigns.

  2. Design and implementation of a new real-time frequency sensor used as hardware countermeasure.

    PubMed

    Jiménez-Naharro, Raúl; Gómez-Galán, Juan Antonio; Sánchez-Raya, Manuel; Gómez-Bravo, Fernando; Pedro-Carrasco, Manuel

    2013-01-01

    A new digital countermeasure against attacks related to the clock frequency is presented. This countermeasure, known as frequency sensor, consists of a local oscillator, a transition detector, a measurement element and an output block. The countermeasure has been designed using a full-custom technique implemented in an Application-Specific Integrated Circuit (ASIC), and the implementation has been verified and characterized with an integrated design using a 0.35 mm standard Complementary Metal Oxide Semiconductor (CMOS) technology (Very Large Scale Implementation-VLSI implementation). The proposed solution is configurable in resolution time and allowed range of period, achieving a minimum resolution time of only 1.91 ns and an initialization time of 5.84 ns. The proposed VLSI implementation shows better results than other solutions, such as digital ones based on semi-custom techniques and analog ones based on band pass filters, all design parameters considered. Finally, a counter has been used to verify the good performance of the countermeasure in avoiding the success of an attack. PMID:24008285

  3. Real-time automatic small infrared target detection using local spectral filtering in the frequency

    NASA Astrophysics Data System (ADS)

    Chen, Hao; Zhang, Hong; Li, Jiafeng; Yuan, Ding; Sun, Mingui

    2014-11-01

    Accurate and fast detection of small infrared target has very important meaning for infrared precise guidance, early warning, video surveillance, etc. Based on human visual attention mechanism, an automatic detection algorithm for small infrared target is presented. In this paper, instead of searching for infrared targets, we model regular patches that do not attract much attention by our visual system. This is inspired by the property that the regular patches in spatial domain turn out to correspond to the spikes in the amplitude spectrum. Unlike recent approaches using global spectral filtering, we define the concept of local maxima suppression using local spectral filtering to smooth the spikes in the amplitude spectrum, thereby producing the pop-out of the infrared targets. In the proposed method, we firstly compute the amplitude spectrum of an input infrared image. Second, we find the local maxima of the amplitude spectrum using cubic facet model. Third, we suppress the local maxima using the convolution of the local spectrum with a low-pass Gaussian kernel of an appropriate scale. At last, the detection result in spatial domain is obtained by reconstructing the 2D signal using the original phase and the log amplitude spectrum by suppressing local maxima. The experiments are performed for some real-life IR images, and the results prove that the proposed method has satisfying detection effectiveness and robustness. Meanwhile, it has high detection efficiency and can be further used for real-time detection and tracking.

  4. Real-time frequency domain temperature and oxygen sensor with a single optical fiber.

    PubMed

    Liao, S C; Xu, Z; Izatt, J A; Alcala, J R

    1997-11-01

    The combined excited-state phosphorescence life-times of an alexandrite crystal and platinum tetraphenylporphyrin Pt(TPP) in a single-fiber sensor are used to monitor temperature and oxygen concentration in the physiological range from 15-45 degrees C and 0-50% O2 with precision of 0.24 degree C and 0.15% O2 and accuracy of 0.28 degree C and 0.2% O2. A 500-micron cubic alexandrite crystal bound to the distal end of a 750-micron-diameter optical fiber core and the Pt(TPP) coated circumferentially with a length of 1 cm from the end of the same fiber are excited with pulsed super-bright blue LED light. This apparatus uses a 125-kHz sampler for data acquisition and frequency domain methods for signal processing. The instrument amplifies both the dc and ac components of the photomultiplier output and band limits the signal to 20 kHz. The fundamental frequency of the excitation is set to 488.3 Hz and the highest harmonic used is the 35th. This bandlimited signal is sampled and averaged over a few hundred cycles in the time domain. The frequency domain representation of the data is obtained by employing fast Fourier transform algorithms. The phase delay and the modulation ratio of each sampled harmonic are then computed. At least four log-spaced harmonic phases or modulations are averaged before decoding the two lifetimes of temperature and oxygen phosphorescent sensors. A component of zero lifetime is introduced to account for the excitation backscatter leakage through optical interference filters seen by the photodetector. Linear and second-order empirical polynomials are employed to compute the temperatures and oxygen concentrations from the inverse lifetimes. In the situation of constant oxygen concentration, the lifetime of Pt(TPP) changes with temperature but can be compensated using the measured temperature lifetime. The system drift is 0.24 degree C for the temperature measurement and 0.59% for the oxygen concentration measurement over 30 h of continuous operation

  5. Real-Time Determination of Absolute Frequency in Continuous-Wave Terahertz Radiation with a Photocarrier Terahertz Frequency Comb Induced by an Unstabilized Femtosecond Laser

    NASA Astrophysics Data System (ADS)

    Minamikawa, Takeo; Hayashi, Kenta; Mizuguchi, Tatsuya; Hsieh, Yi-Da; Abdelsalam, Dahi Ghareab; Mizutani, Yasuhiro; Yamamoto, Hirotsugu; Iwata, Tetsuo; Yasui, Takeshi

    2016-05-01

    A practical method for the absolute frequency measurement of continuous-wave terahertz (CW-THz) radiation uses a photocarrier terahertz frequency comb (PC-THz comb) because of its ability to realize real-time, precise measurement without the need for cryogenic cooling. However, the requirement for precise stabilization of the repetition frequency ( f rep) and/or use of dual femtosecond lasers hinders its practical use. In this article, based on the fact that an equal interval between PC-THz comb modes is always maintained regardless of the fluctuation in f rep, the PC-THz comb induced by an unstabilized laser was used to determine the absolute frequency f THz of CW-THz radiation. Using an f rep-free-running PC-THz comb, the f THz of the frequency-fixed or frequency-fluctuated active frequency multiplier chain CW-THz source was determined at a measurement rate of 10 Hz with a relative accuracy of 8.2 × 10-13 and a relative precision of 8.8 × 10-12 to a rubidium frequency standard. Furthermore, f THz was correctly determined even when fluctuating over a range of 20 GHz. The proposed method enables the use of any commercial femtosecond laser for the absolute frequency measurement of CW-THz radiation.

  6. Intermediate frequency band digitized high dynamic range radiometer system for plasma diagnostics and real-time Tokamak control

    SciTech Connect

    Bongers, W. A.; Beveren, V. van; Westerhof, E.; Goede, A. P. H.; Krijger, B.; Berg, M. A. van den; Graswinckel, M. F.; Schueller, F. C.; Thoen, D. J.; Nuij, P. J. W. M.; Baar, M. R. de; Donne, A. J. H.; Hennen, B. A.; Kantor, M.

    2011-06-15

    An intermediate frequency (IF) band digitizing radiometer system in the 100-200 GHz frequency range has been developed for Tokamak diagnostics and control, and other fields of research which require a high flexibility in frequency resolution combined with a large bandwidth and the retrieval of the full wave information of the mm-wave signals under investigation. The system is based on directly digitizing the IF band after down conversion. The enabling technology consists of a fast multi-giga sample analog to digital converter that has recently become available. Field programmable gate arrays (FPGA) are implemented to accomplish versatile real-time data analysis. A prototype system has been developed and tested and its performance has been compared with conventional electron cyclotron emission (ECE) spectrometer systems. On the TEXTOR Tokamak a proof of principle shows that ECE, together with high power injected and scattered radiation, becomes amenable to measurement by this device. In particular, its capability to measure the phase of coherent signals in the spectrum offers important advantages in diagnostics and control. One case developed in detail employs the FPGA in real-time fast Fourier transform (FFT) and additional signal processing. The major benefit of such a FFT-based system is the real-time trade-off that can be made between frequency and time resolution. For ECE diagnostics this corresponds to a flexible spatial resolution in the plasma, with potential application in smart sensing of plasma instabilities such as the neoclassical tearing mode (NTM) and sawtooth instabilities. The flexible resolution would allow for the measurement of the full mode content of plasma instabilities contained within the system bandwidth.

  7. Monitoring Radiofrequency Ablation Using Real-Time Ultrasound Nakagami Imaging Combined with Frequency and Temporal Compounding Techniques

    PubMed Central

    Zhou, Zhuhuang; Wu, Shuicai; Wang, Chiao-Yin; Ma, Hsiang-Yang; Lin, Chung-Chih; Tsui, Po-Hsiang

    2015-01-01

    Gas bubbles induced during the radiofrequency ablation (RFA) of tissues can affect the detection of ablation zones (necrosis zone or thermal lesion) during ultrasound elastography. To resolve this problem, our previous study proposed ultrasound Nakagami imaging for detecting thermal-induced bubble formation to evaluate ablation zones. To prepare for future applications, this study (i) created a novel algorithmic scheme based on the frequency and temporal compounding of Nakagami imaging for enhanced ablation zone visualization, (ii) integrated the proposed algorithm into a clinical scanner to develop a real-time Nakagami imaging system for monitoring RFA, and (iii) investigated the applicability of Nakagami imaging to various types of tissues. The performance of the real-time Nakagami imaging system in visualizing RFA-induced ablation zones was validated by measuring porcine liver (n = 18) and muscle tissues (n = 6). The experimental results showed that the proposed algorithm can operate on a standard clinical ultrasound scanner to monitor RFA in real time. The Nakagami imaging system effectively monitors RFA-induced ablation zones in liver tissues. However, because tissue properties differ, the system cannot visualize ablation zones in muscle fibers. In the future, real-time Nakagami imaging should be focused on the RFA of the liver and is suggested as an alternative monitoring tool when advanced elastography is unavailable or substantial bubbles exist in the ablation zone. PMID:25658424

  8. Rapid spatial frequency domain inverse problem solutions using look-up tables for real-time processing (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Angelo, Joseph P.; Bigio, Irving J.; Gioux, Sylvain

    2016-03-01

    Imaging technologies working in the spatial frequency domain are becoming increasingly popular for generating wide-field optical property maps, enabling further analysis of tissue parameters such as absorption or scattering. While acquisition methods have witnessed a very rapid growth and are now performing in real-time, processing methods are yet slow preventing information to be acquired and displayed in real-time. In this work, we present solutions for rapid inverse problem solving for optical properties by use of advanced look-up tables. In particular, we present methods and results from a dense, linearized look-up table and an analytical representation that currently run 100 times faster than the standard method and within 10% in both absorption and scattering. With the resulting computation time in the tens of milliseconds range, the proposed techniques enable video-rate feedback of real-time techniques such as snapshot of optical properties (SSOP) imaging, making full video-rate guidance in the clinic possible.

  9. Instantaneous Real-Time Kinematic Decimeter-Level Positioning with BeiDou Triple-Frequency Signals over Medium Baselines

    PubMed Central

    He, Xiyang; Zhang, Xiaohong; Tang, Long; Liu, Wanke

    2015-01-01

    Many applications, such as marine navigation, land vehicles location, etc., require real time precise positioning under medium or long baseline conditions. In this contribution, we develop a model of real-time kinematic decimeter-level positioning with BeiDou Navigation Satellite System (BDS) triple-frequency signals over medium distances. The ambiguities of two extra-wide-lane (EWL) combinations are fixed first, and then a wide lane (WL) combination is reformed based on the two EWL combinations for positioning. Theoretical analysis and empirical analysis is given of the ambiguity fixing rate and the positioning accuracy of the presented method. The results indicate that the ambiguity fixing rate can be up to more than 98% when using BDS medium baseline observations, which is much higher than that of dual-frequency Hatch-Melbourne-Wübbena (HMW) method. As for positioning accuracy, decimeter level accuracy can be achieved with this method, which is comparable to that of carrier-smoothed code differential positioning method. Signal interruption simulation experiment indicates that the proposed method can realize fast high-precision positioning whereas the carrier-smoothed code differential positioning method needs several hundreds of seconds for obtaining high precision results. We can conclude that a relatively high accuracy and high fixing rate can be achieved for triple-frequency WL method with single-epoch observations, displaying significant advantage comparing to traditional carrier-smoothed code differential positioning method. PMID:26703614

  10. Instantaneous Real-Time Kinematic Decimeter-Level Positioning with BeiDou Triple-Frequency Signals over Medium Baselines.

    PubMed

    He, Xiyang; Zhang, Xiaohong; Tang, Long; Liu, Wanke

    2015-01-01

    Many applications, such as marine navigation, land vehicles location, etc., require real time precise positioning under medium or long baseline conditions. In this contribution, we develop a model of real-time kinematic decimeter-level positioning with BeiDou Navigation Satellite System (BDS) triple-frequency signals over medium distances. The ambiguities of two extra-wide-lane (EWL) combinations are fixed first, and then a wide lane (WL) combination is reformed based on the two EWL combinations for positioning. Theoretical analysis and empirical analysis is given of the ambiguity fixing rate and the positioning accuracy of the presented method. The results indicate that the ambiguity fixing rate can be up to more than 98% when using BDS medium baseline observations, which is much higher than that of dual-frequency Hatch-Melbourne-Wübbena (HMW) method. As for positioning accuracy, decimeter level accuracy can be achieved with this method, which is comparable to that of carrier-smoothed code differential positioning method. Signal interruption simulation experiment indicates that the proposed method can realize fast high-precision positioning whereas the carrier-smoothed code differential positioning method needs several hundreds of seconds for obtaining high precision results. We can conclude that a relatively high accuracy and high fixing rate can be achieved for triple-frequency WL method with single-epoch observations, displaying significant advantage comparing to traditional carrier-smoothed code differential positioning method. PMID:26703614

  11. Real-time implementation of frequency-modulated continuous-wave synthetic aperture radar imaging using field programmable gate array.

    PubMed

    Quan, Yinghui; Li, Yachao; Hu, Guibin; Xing, Mengdao

    2015-06-01

    A new miniature linear frequency-modulated continuous-wave radar which mounted on an unmanned aerial vehicle is presented. It allows the accomplishment of high resolution synthetic aperture radar imaging in real-time. Only a Kintex-7 field programmable gate array from Xilinx is utilized for whole signal processing of sophisticated radar imaging algorithms. The proposed hardware architecture achieves remarkable improvement in integration, power consumption, volume, and computing performance over its predecessor designs. The realized design is verified by flight campaigns. PMID:26133857

  12. Particle filter-based estimation of inter-frequency phase bias for real-time GLONASS integer ambiguity resolution

    NASA Astrophysics Data System (ADS)

    Tian, Yumiao; Ge, Maorong; Neitzel, Frank

    2015-11-01

    GLONASS could hardly reach the positioning performance of GPS, especially for fast and real-time precise positioning. One of the reasons is the phase inter-frequency bias (IFB) at the receiver end prevents its integer ambiguity resolution. A number of studies were carried out to achieve the integer ambiguity resolution for GLONASS. Based on some of the revealed IFB characteristics, for instance IFB is a linear function of the received carrier frequency and L1 and L2 have the same IFB in unit of length, most of recent methods recommend estimating the IFB rate together with ambiguities. However, since the two sets of parameters are highly correlated, as demonstrated in previous studies, observations over several hours up to 1 day are needed even with simultaneous GPS observations to obtain a reasonable solution. Obviously, these approaches cannot be applied for real-time positioning. Actually, it can be demonstrated that GLONASS ambiguity resolution should also be available even for a single epoch if the IFB rate is precisely known. In addition, the closer the IFB rate value is to its true value, the larger the fixing RATIO will be. Based on this fact, in this paper, a new approach is developed to estimate the IFB rate by means of particle filtering with the likelihood function derived from RATIO. This approach is evaluated with several sets of experimental data. For both static and kinematic cases, the results show that IFB rates could be estimated precisely just with GLONASS data of a few epochs depending on the baseline length. The time cost with a normal PC can be controlled around 1 s and can be further reduced. With the estimated IFB rate, integer ambiguity resolution is available immediately and as a consequence, the positioning accuracy is improved significantly to the level of GPS fixed solution. Thus the new approach enables real-time precise applications of GLONASS.

  13. Real-time PCR genotyping and frequency of the myostatin F94L mutation in beef cattle breeds.

    PubMed

    Vankan, D M; Waine, D R; Fortes, M R S

    2010-04-01

    This research developed two real-time PCR assays, employing high-resolution melt and allele-specific analysis to accurately genotype the F94L mutation in cattle. This mutation (g.433C > A) in the growth differentiation factor 8 or myostatin gene has recently been shown to be functionally associated with increased muscle mass and carcass yield in cattle. The F94L mutation is not, like other myostatin mutations, associated with reduced fertility and dystocia. It is therefore a candidate for introgression into other breeds to improve retail beef yield and the development of a simple and accurate test to genotype this specific mutation is warranted. Variations in the efficiency of enzyme cleavage compromised the accuracy of genotyping by published methods, potentially resulting in an overestimation of the frequency of the mutant allele. The frequency of the F94L mutation was determined by real-time PCR in 1140 animals from 15 breeds of cattle in Australia. The mutation was present in Simmental (0.8%), Piedmontese (2%), Droughtmaster (4%) and Limousin (94.2%) but not found in Salers, Angus, Poll Hereford, Hereford, Gelbvieh, Charolais, Jersey, Brahman, Holstein, Shorthorn or Maine Anjou. The low prevalence of F94L in all beef breeds except Limousin indicates the significant potential for this mutation to improve retail yield in Australian beef cattle. PMID:22444040

  14. Real-time technique for the characterization of tunable single-frequency lasers

    SciTech Connect

    Strzelecki, E.M.; Cohen, D.A.; Corzine, S.W.; Karin, J.R.; Coldren, L.A.

    1988-06-27

    An all-fiber Mach--Zehnder interferometric system has been developed for characterization of tunable semiconductor lasers. The tuning rate, range, and linearity of directly frequency-modulated lasers as well as laser linewidth are measured using the same system. To investigate the features of the system and demonstrate its usefulness, 1.3 ..mu..m coupled-cavity lasers, tunable with constant amplitude, were characterized. The effects of optical feedback on laser parameters have also been investigated.

  15. Microscopic simulations of shock propagation in condensed media: comparison between real time and frequency domains

    SciTech Connect

    Karo, A.M.; Hardy, J.R.; Mehlman, M.H.

    1985-07-01

    Computer molecular dynamics (CMD) is now recognized as a very powerful technique for examining the microscopic details of a wide variety of chemical and physical phenomena, including the shock-induced fast decomposition processes that characterize the shock-initiation of energetic materials. The purpose of the present paper is to describe some results obtained by new methods of post processing of CMD data. First we present a pictorial history of a canonical system which is bonded with identical potentials and has identical atomic masses. We then present Fourier transforms of the energy components of different units judiciously chosen to show the ''frequency fingerprint'' of the shock impact and passage through specific units of the system, including, e.g., the behavior of spalled fragments. To complement these studies, we also display the behavior of our canonical system when defect (point or line) are present. In these studies we monitor the motion of diatoms above and below a line defect consisting of heavy masses. The Fourier transform techniques provide optimum compromise histories which present neither too much nor too little detail.

  16. Allelic frequency determination of the 24-bp chitotriosidase duplication in the Portuguese population by real-time PCR.

    PubMed

    Rodrigues, M R; Sá Miranda, M C; Amaral, O

    2004-01-01

    Chitotriosidase is a human chitinase produced by macrophages. Its enzymatic activity is markedly elevated in serum of patients suffering from lysosomal storage disorders, as well as other diseases in which macrophages are activated. Therefore, it is a useful tool as a secondary marker in the diagnosis of several disorders including Gaucher disease type 1 and Niemann-Pick disease. The determination of chitotriosidase levels as a diagnosis complement in some lysosomal storage disorders and in enzyme replacement therapy follow-up of Gaucher disease patients is of great importance. However, the fact that a mutation caused by a 24-bp duplication in the CHIT1 gene resulting in deficiency of plasma chitotriosidase activity is very frequent makes the establishment of the frequency of this mutation in different population groups necessary. Furthermore, in order to validate the use of chitotriosidase activity as a marker, it is indispensable to screen individuals for this particular mutation. In this work, we present the results of a study where the allelic frequency of the above mentioned CHIT1 gene mutation was determined in the Portuguese population by real-time PCR. The frequency of carriers encountered in this sample of Portuguese individuals was of 37%. PMID:15528158

  17. In Situ Molecular Level Studies on Membrane Related Peptides and Proteins in Real Time Using Sum Frequency Generation Vibrational Spectroscopy

    PubMed Central

    Ye, Shuji; Nguyen, Khoi Tan; Le Clair, Stéphanie V.; Chen, Zhan

    2009-01-01

    Sum frequency generation (SFG) vibrational spectroscopy has been demonstrated to be a powerful technique to study the molecular structures of surfaces and interfaces in different chemical environments. This review summarizes recent SFG studies on hybrid bilayer membranes and substrate-supported lipid monolayers and bilayers, the interaction between peptides/proteins and lipid monolayers/bilayers, and bilayer perturbation induced by peptides/proteins. To demonstrate the ability of SFG to determine the orientations of various secondary structures, studies on the interaction between different peptides/proteins (melittin, G proteins, almethicin, and tachyplesin I) and lipid bilayers are discussed. Molecular level details revealed by SFG in these studies show that SFG can provide a unique understanding on the interactions between a lipid monolayer/bilayer and peptides/proteins in real time, in situ and without any exogenous labeling. PMID:19306928

  18. A real-time algorithm for the harmonic estimation and frequency tracking of dominant components in fusion plasma magnetic diagnostics

    SciTech Connect

    Alves, D.; Coelho, R. [Associação Euratom Collaboration: JET-EFDA Contributors

    2013-08-15

    The real-time tracking of instantaneous quantities such as frequency, amplitude, and phase of components immerse in noisy signals has been a common problem in many scientific and engineering fields such as power systems and delivery, telecommunications, and acoustics for the past decades. In magnetically confined fusion research, extracting this sort of information from magnetic signals can be of valuable assistance in, for instance, feedback control of detrimental magnetohydrodynamic modes and disruption avoidance mechanisms by monitoring instability growth or anticipating mode-locking events. This work is focused on nonlinear Kalman filter based methods for tackling this problem. Similar methods have already proven their merits and have been successfully employed in this scientific domain in applications such as amplitude demodulation for the motional Stark effect diagnostic. In the course of this work, three approaches are described, compared, and discussed using magnetic signals from the Joint European Torus tokamak plasma discharges for benchmarking purposes.

  19. Power management and frequency regulation for microgrid and smart grid: A real-time demand response approach

    NASA Astrophysics Data System (ADS)

    Pourmousavi Kani, Seyyed Ali

    Future power systems (known as smart grid) will experience a high penetration level of variable distributed energy resources to bring abundant, affordable, clean, efficient, and reliable electric power to all consumers. However, it might suffer from the uncertain and variable nature of these generations in terms of reliability and especially providing required balancing reserves. In the current power system structure, balancing reserves (provided by spinning and non-spinning power generation units) usually are provided by conventional fossil-fueled power plants. However, such power plants are not the favorite option for the smart grid because of their low efficiency, high amount of emissions, and expensive capital investments on transmission and distribution facilities, to name a few. Providing regulation services in the presence of variable distributed energy resources would be even more difficult for islanded microgrids. The impact and effectiveness of demand response are still not clear at the distribution and transmission levels. In other words, there is no solid research reported in the literature on the evaluation of the impact of DR on power system dynamic performance. In order to address these issues, a real-time demand response approach along with real-time power management (specifically for microgrids) is proposed in this research. The real-time demand response solution is utilized at the transmission (through load-frequency control model) and distribution level (both in the islanded and grid-tied modes) to provide effective and fast regulation services for the stable operation of the power system. Then, multiple real-time power management algorithms for grid-tied and islanded microgrids are proposed to economically and effectively operate microgrids. Extensive dynamic modeling of generation, storage, and load as well as different controller design are considered and developed throughout this research to provide appropriate models and simulation

  20. Performance of a Frequency-Hopped Real-Time Remote Control System in a Multiple Access Scenario

    NASA Astrophysics Data System (ADS)

    Cervantes, Frank

    A recent trend is observed in the context of the radio-controlled aircrafts and automobiles within the hobby grade category and Unmanned Aerial Vehicles (UAV) applications moving to the well-known Industrial, Scientific and Medical (ISM) band. Based on this technological fact, the present thesis evaluates an individual user performance by featuring a multiple-user scenario where several point-to-point co-located real-time Remote Control (RC) applications operate using Frequency Hopping Spread Spectrum (FHSS) as a medium access technique in order to handle interference efficiently. Commercial-off-the-shelf wireless transceivers ready to operate in the ISM band are considered as the operational platform supporting the above-mentioned applications. The impact of channel impairments and of different critical system engineering issues, such as working with real clock oscillators and variable packet duty cycle, are considered. Based on the previous, simulation results allowed us to evaluate the range of variation for those parameters for an acceptable system performance under Multiple Access (MA) environments.

  1. Comparison of delay compensation methods for real-time hybrid simulation using frequency-domain evaluation index

    NASA Astrophysics Data System (ADS)

    Weijie, Xu; Tong, Guo; Cheng, Chen

    2016-03-01

    The delay compensation method plays an essential role in maintaining the stability and achieving accurate real-time hybrid simulation results. The effectiveness of various compensation methods in different test scenarios, however, needs to be quantitatively evaluated. In this study, four compensation methods (i.e., the polynomial extrapolation, the linear acceleration extrapolation, the inverse compensation and the adaptive inverse compensation) are selected and compared experimentally using a frequency evaluation index (FEI) method. The effectiveness of the FEI method is first verified through comparison with the discrete transfer function approach for compensation methods assuming constant delay. Incomparable advantage is further demonstrated for the FEI method when applied to adaptive compensation methods, where the discrete transfer function approach is difficult to implement. Both numerical simulation and laboratory tests with predefined displacements are conducted using sinusoidal signals and random signals as inputs. Findings from numerical simulation and experimental results demonstrate that the FEI method is an efficient and effective approach to compare the performance of different compensation methods, especially for those requiring adaptation of compensation parameters.

  2. Real-Time PCR for Quantitative Analysis of Human Commensal Escherichia coli Populations Reveals a High Frequency of Subdominant Phylogroups

    PubMed Central

    Smati, Mounira; Clermont, Olivier; Le Gal, Frédéric; Schichmanoff, Olivier; Jauréguy, Françoise; Eddi, Alain; Picard, Bertrand

    2013-01-01

    Escherichia coli is divided into four main phylogenetic groups, which each exhibit ecological specialization. To understand the population structure of E. coli in its primary habitat, we directly assessed the relative proportions of these phylogroups from the stools of 100 healthy human subjects using a new real-time PCR method, which allows a large number of samples to be studied. The detection threshold for our technique was 0.1% of the E. coli population, i.e., 105 CFU/g of feces; in other methods based on individual colony analysis, the threshold is 10%. One, two, three, or four phylogenetic groups were simultaneously found in 21%, 48%, 21%, and 8% of the subjects, respectively. Phylogroups present at a threshold of less than 10% of the population were found in 40% of the subjects, revealing high within-individual diversity. Phylogroups A and B2 were detected in 74% and 70% of the subjects, respectively; phylogroups B1 and D were detected in 36% and 32%, respectively. When phylogroup B2 was dominant, it tended not to cooccur with other phylogroups. In contrast, other phylogroups were present when phylogroup A was dominant. These data indicate a complex pattern of interactions between the members of a single species within the human gut and identify a reservoir of clones that are present at a low frequency. The presence of these minor clones could explain the fluctuation in the composition of the E. coli microbiota within single individuals that may be seen over time. They could also constitute reservoirs of virulent and/or resistant strains. PMID:23770894

  3. Real-time flutter identification

    NASA Technical Reports Server (NTRS)

    Roy, R.; Walker, R.

    1985-01-01

    The techniques and a FORTRAN 77 MOdal Parameter IDentification (MOPID) computer program developed for identification of the frequencies and damping ratios of multiple flutter modes in real time are documented. Physically meaningful model parameterization was combined with state of the art recursive identification techniques and applied to the problem of real time flutter mode monitoring. The performance of the algorithm in terms of convergence speed and parameter estimation error is demonstrated for several simulated data cases, and the results of actual flight data analysis from two different vehicles are presented. It is indicated that the algorithm is capable of real time monitoring of aircraft flutter characteristics with a high degree of reliability.

  4. Real-time observation of phonon-polariton dynamics in ferroelectric LiNbO3 in time-frequency space

    NASA Astrophysics Data System (ADS)

    Ikegaya, Yuki; Sakaibara, Hiroyuki; Minami, Yasuo; Katayama, Ikufumi; Takeda, Jun

    2015-08-01

    We demonstrate the real-time observation of phonon-polariton propagation in ferroelectric LiNbO3 using a single-shot spectroscopic setup that employs an echelon mirror. The echelon mirror provides a spatially encoded time delay for the probe pulse; therefore, the ultrafast transient behavior of materials can be detected on a single-shot basis. Using optical Kerr gate apparatus, forward and backward propagating E-mode phonon-polaritons were simultaneously induced via an impulsive stimulated Raman scattering process, and subsequently, their dynamics were readily mapped in time-frequency space using heterodyne detection. The two phonon-polaritons appeared on opposite sides of the central probe wavelength and were symmetrically imaged against the ordinary and extraordinary probe lights. By taking into account coupling of the lowest E-mode phonon-polariton to a low-frequency relaxational mode, not only the phonon-polariton dispersion but also the wavevector dependence of the damping rate was unveiled and quantitatively evaluated.

  5. Real-time terahertz wave imaging by nonlinear optical frequency up-conversion in a 4-dimethylamino-N'-methyl-4'-stilbazolium tosylate crystal

    NASA Astrophysics Data System (ADS)

    Fan, Shuzhen; Qi, Feng; Notake, Takashi; Nawata, Kouji; Matsukawa, Takeshi; Takida, Yuma; Minamide, Hiroaki

    2014-03-01

    Real-time terahertz (THz) wave imaging has wide applications in areas such as security, industry, biology, medicine, pharmacy, and arts. In this letter, we report on real-time room-temperature THz imaging by nonlinear optical frequency up-conversion in organic 4-dimethylamino-N'-methyl-4'-stilbazolium tosylate crystal. The active projection-imaging system consisted of (1) THz wave generation, (2) THz-near-infrared hybrid optics, (3) THz wave up-conversion, and (4) an InGaAs camera working at 60 frames per second. The pumping laser system consisted of two optical parametric oscillators pumped by a nano-second frequency-doubled Nd:YAG laser. THz-wave images of handmade samples at 19.3 THz were taken, and videos of a sample moving and a ruler stuck with a black polyethylene film moving were supplied online to show real-time ability. Thanks to the high speed and high responsivity of this technology, real-time THz imaging with a higher signal-to-noise ratio than a commercially available THz micro-bolometer camera was proven to be feasible. By changing the phase-matching condition, i.e., by changing the wavelength of the pumping laser, we suggest THz imaging with a narrow THz frequency band of interest in a wide range from approximately 2 to 30 THz is possible.

  6. Kalman filter methods for real-time frequency and mode number estimation of MHD activity in tokamak plasmas

    NASA Astrophysics Data System (ADS)

    Alves, D.; Coelho, R.; JET EFDA contributors, the

    2013-10-01

    Magnetohydrodynamic (MHD) activity in magnetically confined fusion experiments is often associated with detrimental effects such as increased radial transport and consequent loss of confinement. In particular, the (2,1) neoclassical tearing mode (NTM), when proceeding to mode-locking, is a potentially disruptive instability hence with the potential to compromise the mechanical integrity of the machine. It is therefore quite significant to be able to characterize in real-time the most virulent and performance limiting instabilities such that adequate mitigation or complete stabilization using feedback control methods are employed during the plasma discharge. This work proposes a Kalman filter (KF) based mechanism for providing, in real-time, the amplitude and phase evolution of instabilities within a predefined set of mode numbers. The method relies on two KF implementations: a non-linear KF isolating the non-stationary dominant signal component of a sensor measurement and subsequently a linear KF which projects the former, for a collection of sensors, onto a predefined set of mode numbers. A basic overview of algorithms commonly used for real-time mode number analysis is also presented along with applications of the proposed algorithm to recently recorded data of the Joint European Torus (JET) tokamak.

  7. Real-time radiography

    SciTech Connect

    Bossi, R.H.; Oien, C.T.

    1981-02-26

    Real-time radiography is used for imaging both dynamic events and static objects. Fluorescent screens play an important role in converting radiation to light, which is then observed directly or intensified and detected. The radiographic parameters for real-time radiography are similar to conventional film radiography with special emphasis on statistics and magnification. Direct-viewing fluoroscopy uses the human eye as a detector of fluorescent screen light or the light from an intensifier. Remote-viewing systems replace the human observer with a television camera. The remote-viewing systems have many advantages over the direct-viewing conditions such as safety, image enhancement, and the capability to produce permanent records. This report reviews real-time imaging system parameters and components.

  8. Real-Time Simulation

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Coryphaeus Software, founded in 1989 by former NASA electronic engineer Steve Lakowske, creates real-time 3D software. Designer's Workbench, the company flagship product, is a modeling and simulation tool for the development of both static and dynamic 3D databases. Other products soon followed. Activation, specifically designed for game developers, allows developers to play and test the 3D games before they commit to a target platform. Game publishers can shorten development time and prove the "playability" of the title, maximizing their chances of introducing a smash hit. Another product, EasyT, lets users create massive, realistic representation of Earth terrains that can be viewed and traversed in real time. Finally, EasyScene software control the actions among interactive objects within a virtual world. Coryphaeus products are used on Silican Graphics workstation and supercomputers to simulate real-world performance in synthetic environments. Customers include aerospace, aviation, architectural and engineering firms, game developers, and the entertainment industry.

  9. Experimental investigations in transmission performance of real-time long-reach adaptively modulated direct-detection optical-orthogonal frequency division multiplexing systems

    NASA Astrophysics Data System (ADS)

    Chen, Ming; He, Jing; Tang, Jin; Chen, Lin

    2014-09-01

    A real-time base-band orthogonal frequency division multiplexing (OFDM) transceiver with symbol synchronization, channel equalization, sampling clock frequency synchronization, and adaptive modulation technique is successfully implemented by field programmable gate arrays and a 2.5-GSps digital-to-analog converter and analog-to-digital converter. The real-time optical OFDM signal at a raw bit rate of 5.156 Gbps within about 1.1-GHz bandwidth transmission over 100-km standard single-mode fiber (SSMF) is experimentally investigated in a simple intensity-modulation and direct-detection system. The experimental results show that the real-time system has a good bit error rate (BER) performance by using an adaptive modulation technique according to the conditions on the subchannels. After 100-km SSMF transmission, at a BER of 1×10-3, the power penalty is <1 dB. Moreover, there is a negligible penalty between the off-line and real-time digital signal processing results.

  10. Microelectrical Impedance Spectroscopy for the Differentiation between Normal and Cancerous Human Urothelial Cell Lines: Real-Time Electrical Impedance Measurement at an Optimal Frequency

    PubMed Central

    Park, Yangkyu; Kim, Hyeon Woo; Yun, Joho; Seo, Seungwan; Park, Chang-Ju; Lee, Jeong Zoo; Lee, Jong-Hyun

    2016-01-01

    Purpose. To distinguish between normal (SV-HUC-1) and cancerous (TCCSUP) human urothelial cell lines using microelectrical impedance spectroscopy (μEIS). Materials and Methods. Two types of μEIS devices were designed and used in combination to measure the impedance of SV-HUC-1 and TCCSUP cells flowing through the channels of the devices. The first device (μEIS-OF) was designed to determine the optimal frequency at which the impedance of two cell lines is most distinguishable. The μEIS-OF trapped the flowing cells and measured their impedance at a frequency ranging from 5 kHz to 1 MHz. The second device (μEIS-RT) was designed for real-time impedance measurement of the cells at the optimal frequency. The impedance was measured instantaneously as the cells passed the sensing electrodes of μEIS-RT. Results. The optimal frequency, which maximized the average difference of the amplitude and phase angle between the two cell lines (p < 0.001), was determined to be 119 kHz. The real-time impedance of the cell lines was measured at 119 kHz; the two cell lines differed significantly in terms of amplitude and phase angle (p < 0.001). Conclusion. The μEIS-RT can discriminate SV-HUC-1 and TCCSUP cells by measuring the impedance at the optimal frequency determined by the μEIS-OF. PMID:26998490

  11. Real-time multi-signal frequency tracking with a bank of notch filters to estimate the respiratory rate from the ECG.

    PubMed

    Mirmohamadsadeghi, Leila; Vesin, Jean-Marc

    2016-09-01

    Measuring the instantaneous frequency of a signal rapidly and accurately is essential in many applications. However, the instantaneous frequency by definition is a parameter difficult to determine. Fourier-based methods introduce estimation delays as computations are performed in a time-window. Instantaneous methods based on the Hilbert transform lack robustness. State-of-the-art adaptive filters yield accurate estimates, however, with an adaptation delay. In this study we propose an algorithm based on short length-3 FIR notch filters to estimate the instantaneous frequency of a signal at each sample, in a real-time manner and with very low delay. The output powers of a bank of the above-mentioned filters are used in a recursive weighting scheme to estimate the dominant frequency of the input. This scheme has been extended to process multiple inputs containing a common frequency by introducing an additional weighting scheme upon the inputs. The algorithm was tested on synthetic data and then evaluated on real biomedical data, i.e. the estimation of the respiratory rate from the electrocardiogram. It was shown that the proposed method provided more accurate estimates with less delay than those of state-of-the-art methods. By virtue of its simplicity and good performance, the proposed method is a worthy candidate to be used in biomedical applications, for example in health monitoring developments based on portable and automatic devices. PMID:27510318

  12. Filtering of high modal frequencies for stable real-time explicit integration of deformable objects using the Finite Element Method.

    PubMed

    Aguinaga, Iker; Fierz, Basil; Spillmann, Jonas; Harders, Matthias

    2010-12-01

    The behavior, performance, and run-time of mechanical simulations in interactive virtual surgery depend heavily on the type of numerical differential equation solver used to integrate in time the dynamic equations obtained from simulation methods, such as the Finite Element Method. Explicit solvers are fast but only conditionally stable. The condition number of the stiffness matrix limits the highest possible time step. This limit is related to the geometrical properties of the underlying mesh, such as element shape and size. In fact, it can be governed by a small set of ill-shaped elements. For many applications this issue can be solved a priori by a careful meshing. However, when meshes are cut during interactive surgery simulation, it is difficult and computationally expensive to control the quality of the resulting elements. As an alternative, we propose to modify the elemental stiffness matrices directly in order to ensure stability. In this context, we first investigate the behavior of the eigenmodes of the elemental stiffness matrix in a Finite Element Method. We then propose a simple filter to reduce high model frequencies and thus allow larger time steps, while maintaining the general mechanical behavior. PMID:20869390

  13. Real-Time PCR

    NASA Astrophysics Data System (ADS)

    Evrard, A.; Boulle, N.; Lutfalla, G. S.

    Over the past few years there has been a considerable development of DNA amplification by polymerase chain reaction (PCR), and real-time PCR has now superseded conventional PCR techniques in many areas, e.g., the quantification of nucleic acids and genotyping. This new approach is based on the detection and quantification of a fluorescent signal proportional to the amount of amplicons generated by PCR. Real-time detection is achieved by coupling a thermocycler with a fluorimeter. This chapter discusses the general principles of quantitative real-time PCR, the different steps involved in implementing the technique, and some examples of applications in medicine. The polymerase chain reaction (PCR) provides a way of obtaining a large number of copies of a double-stranded DNA fragment of known sequence. This DNA amplification technique, developed in 1985 by K. Mullis (Cetus Corporation), saw a spectacular development over the space of a few years, revolutionising the methods used up to then in molecular biology. Indeed, PCR has many applications, such as the detection of small amounts of DNA, cloning, and quantitative analysis (assaying), each of which will be discussed further below.

  14. Real-time magnetic nanothermometry: The use of magnetization of magnetic nanoparticles assessed under low frequency triangle-wave magnetic fields

    NASA Astrophysics Data System (ADS)

    Zhong, Jing; Liu, Wenzhong; Jiang, Ling; Yang, Ming; Morais, Paulo Cesar

    2014-09-01

    In this study, we propose and demonstrate the usefulness of employing time-varying magnetization of a magnetic nanoparticle (MNP) based sample, induced by low frequency (f = 25 Hz) triangular-wave magnetic field, to achieve the approach of real-time recording of magnetization curve, which allows precise and noninvasive temperature probing with real-time performance. Moreover, the present report introduces the design and performed the test of a detection system for accurate and real-time recording of the magnetization curve of MNP-based samples. We found that by employing the magnetization curve of a magnetic fluid sample containing magnetite nanoparticles of about 30 nm in diameter the accuracy of the temperature probing is about 0.32 K (0.1% relative accuracy), with response time of 1 s. Furthermore, an increase in response time from 1 to 8 s improves the accuracy of temperature probing from 0.32 to 0.20 K. Finally, we envisage that breakthroughs in clinical hyperthermia, targeted drug delivery and basic cell research can be accomplished while using the approach reported in this study.

  15. Real-time monitoring of cardiac radio-frequency ablation lesion formation using an optical coherence tomography forward-imaging catheter

    PubMed Central

    Fleming, Christine P.; Wang, Hui; Quan, Kara J.; Rollins, Andrew M.

    2010-01-01

    Radio-frequency ablation (rfa) is the standard of care for the treatment of cardiac arrhythmias; however, there are no direct measures of the successful delivery of ablation lesions. Optical coherence tomography (OCT) imaging has the potential to provide real-time monitoring of cardiac rfa therapy, visualizing lesion formation and assessing tissue contact in the presence of blood. A rfa-compatible forward-imaging conical scanning probe is prototyped to meet this need. The forward-imaging probe provides circular scanning, with a 2-mm scan diameter and 30-μm spot size. During the application of rf energy, dynamics are recorded at 20 frames per second with a 40-kHz A-line rate. Real-time monitoring of cardiac rfa lesion formation and imaging in the presence of blood is demonstrated ex vivo in a swine left ventricle with a forward, flexible, circular scanning OCT catheter. PMID:20614999

  16. Non-line-of-sight (NLOS), secure, low-probability of intercept (LPI), antijam (AJ), high frequency (HF), real time video communication system

    SciTech Connect

    Lupinetti, F.

    1988-01-01

    This paper outlines a video communication system capable of non-line-of-sight (NLOS), secure, low-probability of intercept (LPI), antijam, real time transmission and reception of video information in a tactical enviroment. An introduction to a class of ternary PN sequences is presented to familiarize the reader with yet another avenue for spreading and despreading baseband information. The use of the high frequency (HF) band (1.5 to 30 MHz) for real time video transmission is suggested to allow NLOS communication. The spreading of the baseband information by means of multiple nontrivially different ternary pseudonoise (PN) sequence is used in order to assure encryption of the signal, enhanced security, a good degree of LPI, and good antijam features. 18 refs., 3 figs., 1 tab.

  17. Real time Faraday spectrometer

    DOEpatents

    Smith, Jr., Tommy E.; Struve, Kenneth W.; Colella, Nicholas J.

    1991-01-01

    This invention uses a dipole magnet to bend the path of a charged particle beam. As the deflected particles exit the magnet, they are spatially dispersed in the bend-plane of the magnet according to their respective momenta and pass to a plurality of chambers having Faraday probes positioned therein. Both the current and energy distribution of the particles is then determined by the non-intersecting Faraday probes located along the chambers. The Faraday probes are magnetically isolated from each other by thin metal walls of the chambers, effectively providing real time current-versus-energy particle measurements.

  18. Real-Time PCR Genotyping Assay for GM2 Gangliosidosis Variant 0 in Toy Poodles and the Mutant Allele Frequency in Japan

    PubMed Central

    RAHMAN, Mohammad Mahbubur; YABUKI, Akira; KOHYAMA, Moeko; MITANI, Sawane; MIZUKAMI, Keijiro; UDDIN, Mohammad Mejbah; CHANG, Hye-Sook; KUSHIDA, Kazuya; KISHIMOTO, Miori; YAMABE, Remi; YAMATO, Osamu

    2013-01-01

    ABSTRACT GM2 gangliosidosis variant 0 (Sandhoff disease, SD) is a fatal, progressive neurodegenerative lysosomal storage disease caused by mutations of the HEXB gene. In canine SD, a pathogenic mutation (c.283delG) of the canine HEXB gene has been identified in toy poodles. In the present study, a TaqMan probe-based real-time PCR genotyping assay was developed and evaluated for rapid and large-scale genotyping and screening for this mutation. Furthermore, a genotyping survey was carried out in a population of toy poodles in Japan to determine the current mutant allele frequency. The real-time PCR assay clearly showed all genotypes of canine SD. The assay was suitable for large-scale survey as well as diagnosis, because of its high throughput and rapidity. The genotyping survey demonstrated a carrier frequency of 0.2%, suggesting that the current mutant allele frequency is low in Japan. However, there may be population stratification in different places, because of the founder effect by some carriers. Therefore, this new assay will be useful for the prevention and control of SD in toy poodles. PMID:24161966

  19. Real-time simultaneous single snapshot of optical properties and blood flow using coherent spatial frequency domain imaging (cSFDI).

    PubMed

    Ghijsen, Michael; Choi, Bernard; Durkin, Anthony J; Gioux, Sylvain; Tromberg, Bruce J

    2016-03-01

    In this work we present and validate a wide-field method for the real-time mapping of tissue absorption, scattering and blood flow properties over wide regions of tissue (15 cm x 15 cm) with high temporal resolution (50 frames per second). We achieve this by applying Fourier Domain demodulation techniques to coherent spatial frequency domain imaging to extract optical properties and speckle flow index from a single snapshot. Applying this technique to forearm reactive hyperemia protocols demonstrates the ability to resolve intrinsic physiological signals such as the heart beat waveform and the buildup of deoxyhemoglobin associated with oxygen consumption. PMID:27231595

  20. Real-time simultaneous single snapshot of optical properties and blood flow using coherent spatial frequency domain imaging (cSFDI)

    PubMed Central

    Ghijsen, Michael; Choi, Bernard; Durkin, Anthony J.; Gioux, Sylvain; Tromberg, Bruce J.

    2016-01-01

    In this work we present and validate a wide-field method for the real-time mapping of tissue absorption, scattering and blood flow properties over wide regions of tissue (15 cm x 15 cm) with high temporal resolution (50 frames per second). We achieve this by applying Fourier Domain demodulation techniques to coherent spatial frequency domain imaging to extract optical properties and speckle flow index from a single snapshot. Applying this technique to forearm reactive hyperemia protocols demonstrates the ability to resolve intrinsic physiological signals such as the heart beat waveform and the buildup of deoxyhemoglobin associated with oxygen consumption. PMID:27231595

  1. Laser Frequency and Time

    NASA Astrophysics Data System (ADS)

    Hänsch, Theodor W.

    2003-04-01

    The following two contributions in this volume are highlighting some remarkable recent developments at the interface between precision laser spectroscopy and ultrafast laser physics. After decades of struggle, we have finally found a practical method for measuring the frequency of light with extreme precision [1]. Femtosecond laser optical frequency comb synthesizers are opening exciting new perspectives for atomic spectroscopy and they can provide the clockwork for optical atomic clocks that will eventually far surpass the accuracy of the best microwave cesium clocks. J. C. Bergquist et al. [2] are reporting on a first optical atomic clock at NIST based on a single trapped Hg+ ion. The contribution by Jun Ye et al. [3] is illustrating the wealth of new opportunities for femtosecond laser frequency combs in the frequency and time domain.

  2. Real time high frequency monitoring of water quality in river streams using a UV-visible spectrometer: interest, limits and consequences for monitoring strategies

    NASA Astrophysics Data System (ADS)

    Faucheux, Mikaël; Fovet, Ophélie; Gruau, Gérard; Jaffrézic, Anne; Petitjean, Patrice; Gascuel-Odoux, Chantal; Ruiz, Laurent

    2013-04-01

    Stream water chemistry is highly variable in space and time, therefore high frequency water quality measurement methods are likely to lead to conceptual advances in the hydrological sciences. Sub-daily data on water quality improve the characterization of pollutant sources and pathways during flood events as well as during long-term periods [1]. However, real time, high frequency monitoring devices needs to be properly calibrated and validated in real streams. This study analyses data from in situ monitoring of a stream water quality. During two hydrological years (2010-11, 2011-12), a submersible UV-visible spectrometer (Scan Spectrolyser) was used for surface water quality measurement at the outlet of a headwater catchment located at Kervidy-Naizin, Western France (AgrHys long-term hydrological observatory, http://www.inra.fr/ore_agrhys/). The spectrometer is reagentless and equipped with an auto-cleaning system. It allows real time, in situ and high frequency (20 min) measurements and uses a multiwavelengt spectral (200-750 nm) for simultaneous measurement of nitrate, dissolved organic carbon (DOC) and total suspended solids (TSS). A global calibration based on a PLS (Partial Least Squares) regression is provided by the manufacturer as default configuration of the UV-visible spectrometer. We carried out a local calibration of the spectrometer based on nitrates and DOC concentrations analysed in the laboratory from daily manual sampling and sub-daily automatic sampling of flood events. TSS results are compared with 15 min turbidity records from a continuous turdidimeter (Ponsel). The results show a good correlation between laboratory data and spectrometer data both during basis flows periods and flood events. However, the local calibration gives better results than the global one. Nutrient fluxes estimates based on high and different low frequency time series (daily to monthly) are compared to discuss the implication for environmental monitoring strategies. Such

  3. Real time automated inspection

    DOEpatents

    Fant, Karl M.; Fundakowski, Richard A.; Levitt, Tod S.; Overland, John E.; Suresh, Bindinganavle R.; Ulrich, Franz W.

    1985-01-01

    A method and apparatus relating to the real time automatic detection and classification of characteristic type surface imperfections occurring on the surfaces of material of interest such as moving hot metal slabs produced by a continuous steel caster. A data camera transversely scans continuous lines of such a surface to sense light intensities of scanned pixels and generates corresponding voltage values. The voltage values are converted to corresponding digital values to form a digital image of the surface which is subsequently processed to form an edge-enhanced image having scan lines characterized by intervals corresponding to the edges of the image. The edge-enhanced image is thresholded to segment out the edges and objects formed by the edges are segmented out by interval matching and bin tracking. Features of the objects are derived and such features are utilized to classify the objects into characteristic type surface imperfections.

  4. Real time automated inspection

    DOEpatents

    Fant, K.M.; Fundakowski, R.A.; Levitt, T.S.; Overland, J.E.; Suresh, B.R.; Ulrich, F.W.

    1985-05-21

    A method and apparatus are described relating to the real time automatic detection and classification of characteristic type surface imperfections occurring on the surfaces of material of interest such as moving hot metal slabs produced by a continuous steel caster. A data camera transversely scans continuous lines of such a surface to sense light intensities of scanned pixels and generates corresponding voltage values. The voltage values are converted to corresponding digital values to form a digital image of the surface which is subsequently processed to form an edge-enhanced image having scan lines characterized by intervals corresponding to the edges of the image. The edge-enhanced image is thresholded to segment out the edges and objects formed by the edges by interval matching and bin tracking. Features of the objects are derived and such features are utilized to classify the objects into characteristic type surface imperfections. 43 figs.

  5. Real-time PCR genotyping assay for canine progressive rod-cone degeneration and mutant allele frequency in Toy Poodles, Chihuahuas and Miniature Dachshunds in Japan

    PubMed Central

    KOHYAMA, Moeko; TADA, Naomi; MITSUI, Hiroko; TOMIOKA, Hitomi; TSUTSUI, Toshihiko; YABUKI, Akira; RAHMAN, Mohammad Mahbubur; KUSHIDA, Kazuya; MIZUKAMI, Keijiro; YAMATO, Osamu

    2015-01-01

    Canine progressive rod-cone degeneration (PRCD) is a middle- to late-onset, autosomal recessive, inherited retinal disorder caused by a substitution (c.5G>A) in the canine PRCD gene that has been identified in 29 or more purebred dogs. In the present study, a TaqMan probe-based real-time PCR assay was developed and evaluated for rapid genotyping and large-scale screening of the mutation. Furthermore, a genotyping survey was carried out in a population of the three most popular breeds in Japan (Toy Poodles, Chihuahuas and Miniature Dachshunds) to determine the current mutant allele frequency. The assay separated all the genotypes of canine PRCD rapidly, indicating its suitability for large-scale surveys. The results of the survey showed that the mutant allele frequency in Toy Poodles was high enough (approximately 0.09) to allow the establishment of measures for the prevention and control of this disorder in breeding kennels. The mutant allele was detected in Chihuahuas for the first time, but the frequency was lower (approximately 0.02) than that in Toy Poodles. The mutant allele was not detected in Miniature Dachshunds. This assay will allow the selective breeding of dogs from the two most popular breeds (Toy Poodle and Chihuahua) in Japan and effective prevention or control of the disorder. PMID:26549343

  6. Real-time PCR genotyping assay for canine progressive rod-cone degeneration and mutant allele frequency in Toy Poodles, Chihuahuas and Miniature Dachshunds in Japan.

    PubMed

    Kohyama, Moeko; Tada, Naomi; Mitsui, Hiroko; Tomioka, Hitomi; Tsutsui, Toshihiko; Yabuki, Akira; Rahman, Mohammad Mahbubur; Kushida, Kazuya; Mizukami, Keijiro; Yamato, Osamu

    2016-03-01

    Canine progressive rod-cone degeneration (PRCD) is a middle- to late-onset, autosomal recessive, inherited retinal disorder caused by a substitution (c.5G>A) in the canine PRCD gene that has been identified in 29 or more purebred dogs. In the present study, a TaqMan probe-based real-time PCR assay was developed and evaluated for rapid genotyping and large-scale screening of the mutation. Furthermore, a genotyping survey was carried out in a population of the three most popular breeds in Japan (Toy Poodles, Chihuahuas and Miniature Dachshunds) to determine the current mutant allele frequency. The assay separated all the genotypes of canine PRCD rapidly, indicating its suitability for large-scale surveys. The results of the survey showed that the mutant allele frequency in Toy Poodles was high enough (approximately 0.09) to allow the establishment of measures for the prevention and control of this disorder in breeding kennels. The mutant allele was detected in Chihuahuas for the first time, but the frequency was lower (approximately 0.02) than that in Toy Poodles. The mutant allele was not detected in Miniature Dachshunds. This assay will allow the selective breeding of dogs from the two most popular breeds (Toy Poodle and Chihuahua) in Japan and effective prevention or control of the disorder. PMID:26549343

  7. Real time polarimetric dehazing.

    PubMed

    Mudge, Jason; Virgen, Miguel

    2013-03-20

    Remote sensing is a rich topic due to its utility in gathering detailed accurate information from locations that are not economically feasible traveling destinations or are physically inaccessible. However, poor visibility over long path lengths is problematic for a variety of reasons. Haze induced by light scatter is one cause for poor visibility and is the focus of this article. Image haze comes about as a result of light scattering off particles and into the imaging path causing a haziness to appear on the image. Image processing using polarimetric information of light scatter can be used to mitigate image haze. An imaging polarimeter which provides the Stokes values in real time combined with a "dehazing" algorithm can automate image haze removal for instant applications. Example uses are to improve visual display providing on-the-spot detection or imbedding in an active control loop to improve viewing and tracking while on a moving platform. In addition, removing haze in this manner allows the trade space for a system operational waveband to be opened up to bands which are object matched and not necessarily restricted by scatter effects. PMID:23518739

  8. Real-Time Assessment of Tissue Hypoxia In Vivo with Combined Photoacoustics and High-Frequency Ultrasound

    PubMed Central

    Gerling, Marco; Zhao, Ying; Nania, Salvatore; Norberg, K. Jessica; Verbeke, Caroline S.; Englert, Benjamin; Kuiper, Raoul V.; Bergström, Åsa; Hassan, Moustapha; Neesse, Albrecht; Löhr, J. Matthias; Heuchel, Rainer L.

    2014-01-01

    Purpose: In preclinical cancer studies, non-invasive functional imaging has become an important tool to assess tumor development and therapeutic effects. Tumor hypoxia is closely associated with tumor aggressiveness and is therefore a key parameter to be monitored. Recently, photoacoustic (PA) imaging with inherently co-registered high-frequency ultrasound (US) has reached preclinical applicability, allowing parallel collection of anatomical and functional information. Dual-wavelength PA imaging can be used to quantify tissue oxygen saturation based on the absorbance spectrum differences between hemoglobin and deoxyhemoglobin. Experimental Design: A new bi-modal PA/US system for small animal imaging was employed to test feasibility and reliability of dual-wavelength PA for measuring relative tissue oxygenation. Murine models of pancreatic and colon cancer were imaged, and differences in tissue oxygenation were compared to immunohistochemistry for hypoxia in the corresponding tissue regions. Results: Functional studies proved feasibility and reliability of oxygenation detection in murine tissue in vivo. Tumor models exhibited different levels of hypoxia in localized regions, which positively correlated with immunohistochemical staining for hypoxia. Contrast-enhanced imaging yielded complementary information on tissue perfusion using the same system. Conclusion: Bimodal PA/US imaging can be utilized to reliably detect hypoxic tumor regions in murine tumor models, thus providing the possibility to collect anatomical and functional information on tumor growth and treatment response live in longitudinal preclinical studies. PMID:24723982

  9. Start up partial nitrification at low temperature with a real-time control strategy based on blower frequency and pH.

    PubMed

    Gu, Shengbo; Wang, Shuying; Yang, Qing; Yang, Pei; Peng, Yongzhen

    2012-05-01

    In this study, the performance of partial nitrification via nitrite at low temperature was investigated in a pilot-scale sequencing batch reactor (SBR) with a working volume of 7.0m(3). A novel real-time control strategy, based on blower frequency (BF) and pH, was designed and evaluated. The nitrogen break point (NBP) in the BF curve and the nitrate/nitrite apex point (NAP) in the pH curve were used to identify the endpoint of the aerobic and anoxic phases, respectively. The nitrite accumulation rate (NAR) rapidly increased from 19.8% to 90%. Partial nitrification was achieved at low temperature (11-16°C) in 40 days and was stably maintained for as long as 140 days by applying a real-time control strategy based on pH and BF. Fluorescence in situ hybirdization (FISH) results demonstrated that ammonia oxidation bacteria (AOB) had developed into the dominant nitrifying bacteria compared to nitrite oxidation bacteria (NOB) in the system. PMID:22414573

  10. Real-Time Benchmark Suite

    Energy Science and Technology Software Center (ESTSC)

    1992-01-17

    This software provides a portable benchmark suite for real time kernels. It tests the performance of many of the system calls, as well as the interrupt response time and task response time to interrupts. These numbers provide a baseline for comparing various real-time kernels and hardware platforms.

  11. Real-time monitoring of focused ultrasound blood-brain barrier opening via subharmonic acoustic emission detection: implementation of confocal dual-frequency piezoelectric transducers

    NASA Astrophysics Data System (ADS)

    Tsai, Chih-Hung; Zhang, Jia-Wei; Liao, Yi-Yi; Liu, Hao-Li

    2016-04-01

    Burst-tone focused ultrasound exposure in the presence of microbubbles has been demonstrated to be effective at inducing temporal and local opening of the blood-brain barrier (BBB), which promises significant clinical potential to deliver therapeutic molecules into the central nervous system (CNS). Traditional contrast-enhanced imaging confirmation after focused ultrasound (FUS) exposure serves as a post-operative indicator of the effectiveness of FUS-BBB opening, however, an indicator that can concurrently report the BBB status and BBB-opening effectiveness is required to provide effective feedback to implement this treatment clinically. In this study, we demonstrate the use of subharmonic acoustic emission detection with implementation on a confocal dual-frequency piezoelectric ceramic structure to perform real-time monitoring of FUS-BBB opening. A confocal dual-frequency (0.55 MHz/1.1 MHz) focused ultrasound transducer was designed. The 1.1 MHz spherically-curved ceramic was employed to deliver FUS exposure to induce BBB-opening, whereas the outer-ring 0.55 MHz ceramic was employed to detect the subharmonic acoustic emissions originating from the target position. In stage-1 experiments, we employed spectral analysis and performed an energy spectrum density (ESD) calculation. An optimized 0.55 MHz ESD level change was shown to effectively discriminate the occurrence of BBB-opening. Wideband acoustic emissions received from 0.55 MHz ceramics were also analyzed to evaluate its correlations with erythrocyte extravasations. In stage-2 real-time monitoring experiments, we applied the predetermined ESD change as a detection threshold in PC-controlled algorithm to predict the FUS exposure intra-operatively. In stage-1 experiment, we showed that subharmonic ESD presents distinguishable dynamics between intact BBB and opened BBB, and therefore a threshold ESD change level (5.5 dB) can be identified for BBB-opening prediction. Using this ESD change threshold detection as a

  12. Real-time face tracking

    NASA Astrophysics Data System (ADS)

    Liang, Yufeng; Wilder, Joseph

    1998-10-01

    A real-time face tracker is presented in this paper. The system has achieved 15 frames/second tracking using a Pentium 200 PC with a Datacube MaxPCI image processing board and a Panasonic RGB color camera. It tracks human faces in the camera's field of view while people move freely. A stochastic model to characterize the skin color distribution of human skin is used to segment the face and other skin areas from the background. Median filtering is then used to clean up the background noise. Geometric constraints are applied to the segmented image to extract the face from the background. To reduce computation and achieve real-time tracking, 1D projections (horizontal and vertical) of the image are analyzed instead of the 2D image. Run-length- encoding and frequency domain analysis algorithms are used to separate faces from other skin-like blobs. The system is robust to illumination intensity variations and different skin colors. It can be applied to many human-computer interaction applications such as sound locating, lip- reading, gaze tracking and face recognition.

  13. Real-time tracking of CO₂ injected into a subsurface coal fire through high-frequency measurements of the ¹³CO₂ signature.

    PubMed

    Krevor, Samuel C M; Ide, Taku; Benson, Sally M; Orr, Franklin M

    2011-05-01

    CO₂ was injected into a coal fire burning at a depth of 15 m in the subsurface in southwestern Colorado, USA. Measurements were made of the ¹³CO₂ isotopic signature of gas exhaust from an observation well and two surface fissures. The goal of the test was to determine (1) whether CO₂ with a distinct isotopic signature could be used as a tracer to identify flow pathways and travel times in a combustion setting where CO₂ was present in significant quantities in the gases being emitted from the coalbed fire, and (2) to confirm the existence of a self-propagating system of air-intake and combustion gas exhaust that has been previously proposed. CO₂ was injected in three separate periods. The ¹³CO₂ isotopic signature was measured at high frequency (0.5 Hz) before, during, and after the injection periods for gas flowing from fissures over the fire and from gas entering an observation well drilled into the formation just above the fire but near the combustion zone. In two cases, a shift in the isotopic signature of outgassing CO₂ provided clear evidence that injected CO₂ had traveled from the injection well to the observation point, while in a third case, no response was seen and the fissure could not be assumed to have a flowpath connected with the injection well. High-frequency measurements of the ¹³CO₂ signature of gas in observation wells is identified as a viable technique for tracking CO₂ injected into subsurface formations in real-time. In addition, a chimney-like coupled air-intake and exhaust outlet system feeding the combustion of the coal seam was confirmed. This can be used to further develop strategies for extinguishing the fire. PMID:21466184

  14. Real Time Baseball Database

    NASA Astrophysics Data System (ADS)

    Fukue, Yasuhiro

    The author describes the system outline, features and operations of "Nikkan Sports Realtime Basaball Database" which was developed and operated by Nikkan Sports Shimbun, K. K. The system enables to input numerical data of professional baseball games as they proceed simultaneously, and execute data updating at realtime, just-in-time. Other than serving as supporting tool for prepareing newspapers it is also available for broadcasting media, general users through NTT dial Q2 and others.

  15. High precision in Raman frequency achieved using real-time calibration with a neon emission line: application to three-dimensional stress mapping observations.

    PubMed

    Odake, Shoko; Fukura, Satoshi; Kagi, Hiroyuki

    2008-10-01

    A three-dimensional (3D) Raman mapping system with a real-time calibration function was developed for detecting stress distributions in solid materials from subtle frequency shifts in Raman spectra. An atomic emission line of neon at 918.3 cm(-1) when excited at 514.5 nm was used as a wavenumber standard. An emission spectrum of neon and a Raman spectrum from a sample were introduced into a single polychromator using a bifurcated optical fiber. These two spectra were recorded simultaneously on a charge-coupled device (CCD) detector using double-track mode. Energy deviation induced by the fluctuation of laboratory temperature, etc., was removed effectively using the neon emission line. High stability during long measurements was achieved. By applying curve fitting, positions of the Raman line were determined with precision of about 0.05 cm(-1). The present system was applied to measurements of residual pressure around mineral inclusions in a natural diamond: 3D stress mapping was achieved. PMID:18926016

  16. Real-time vision systems

    SciTech Connect

    Johnson, R.; Hernandez, J.E.; Lu, Shin-yee

    1994-11-15

    Many industrial and defence applications require an ability to make instantaneous decisions based on sensor input of a time varying process. Such systems are referred to as `real-time systems` because they process and act on data as it occurs in time. When a vision sensor is used in a real-time system, the processing demands can be quite substantial, with typical data rates of 10-20 million samples per second. A real-time Machine Vision Laboratory (MVL) was established in FY94 to extend our years of experience in developing computer vision algorithms to include the development and implementation of real-time vision systems. The laboratory is equipped with a variety of hardware components, including Datacube image acquisition and processing boards, a Sun workstation, and several different types of CCD cameras, including monochrome and color area cameras and analog and digital line-scan cameras. The equipment is reconfigurable for prototyping different applications. This facility has been used to support several programs at LLNL, including O Division`s Peacemaker and Deadeye Projects as well as the CRADA with the U.S. Textile Industry, CAFE (Computer Aided Fabric Inspection). To date, we have successfully demonstrated several real-time applications: bullet tracking, stereo tracking and ranging, and web inspection. This work has been documented in the ongoing development of a real-time software library.

  17. Real-time software receiver

    NASA Technical Reports Server (NTRS)

    Ledvina, Brent M. (Inventor); Psiaki, Mark L. (Inventor); Powell, Steven P. (Inventor); Kintner, Jr., Paul M. (Inventor)

    2007-01-01

    A real-time software receiver that executes on a general purpose processor. The software receiver includes data acquisition and correlator modules that perform, in place of hardware correlation, baseband mixing and PRN code correlation using bit-wise parallelism.

  18. Real-time refinery optimization

    SciTech Connect

    Kennedy, J.P.

    1989-05-01

    This article discusses refinery operation with specific consideration of the topics of: gasoline; control projects; catalytic reforming control; hydrocracker control packages; blending optimization; real-time data acquisition; and other plant automation packages.

  19. Real-time software receiver

    NASA Technical Reports Server (NTRS)

    Ledvina, Brent M. (Inventor); Psiaki, Mark L. (Inventor); Powell, Steven P. (Inventor); Kintner, Jr., Paul M. (Inventor)

    2006-01-01

    A real-time software receiver that executes on a general purpose processor. The software receiver includes data acquisition and correlator modules that perform, in place of hardware correlation, baseband mixing and PRN code correlation using bit-wise parallelism.

  20. Real Time Data System (RTDS)

    NASA Technical Reports Server (NTRS)

    Muratore, John F.

    1991-01-01

    Lessons learned from operational real time expert systems are examined. The basic system architecture is discussed. An expert system is any software that performs tasks to a standard that would normally require a human expert. An expert system implies knowledge contained in data rather than code. And an expert system implies the use of heuristics as well as algorithms. The 15 top lessons learned by the operation of a real time data system are presented.

  1. Time, Frequency and Physical Measurement.

    ERIC Educational Resources Information Center

    Hellwig, Helmut; And Others

    1978-01-01

    Describes several developments in atomic clocks and frequency standards pointing out the feasibility and practicality in adopting a unified standard of time and frequency to replace other base standards of length, mass, and temperature. (GA)

  2. The ALMA Real Time Control System

    NASA Astrophysics Data System (ADS)

    Kern, Jeffrey S.; Juerges, Thomas A.; Marson, Ralph G.

    2009-01-01

    The Atacama Large Millimeter Array (ALMA) is a revolutionary millimeter and submillimeter array being developed on the Atacama plateau of northern Chile. An international partnership lead by NRAO, ESO, and NAOJ this powerful and flexible telescope will provide unprecedented observations of this relatively unexplored frequency range. The control subsystem for the Atacama Large Millimeter Array must coordinate the monitor and control of at least sixty six antennas (in four different styles), two correlators, and all of the ancillary equipment (samplers, local oscillators, front ends, etc.). This equipment will be spread over tens of kilometers and operated remotely. Operation of the array requires a robust, scalable, and maintainable real time control system. The real time control system is responsible for monitoring and control of any devices where there are fixed deadlines. Examples in the ALMA context are antenna pointing and fringe tracking. Traditionally the real time portion of a large software system is an intricate and error prone portion of the software. As a result the real time portion is very expensive in terms of effort expended both during construction and during maintenance phases of a project. The ALMA real time control system uses a Linux based real time operating system to interact with the hardware and the CORBA based ALMA Common Software to communicate in the distributed computing environment. Mixing the requirements of real time computing and the non-deterministic CORBA middleware has produced an interesting design. We discuss the architecture, design, and implementation of the ALMA real time control system. Highlight some lessons learned along the way, and justify our assertion that this should be the last large scale real time control system in radio astronomy.

  3. Frequency of Pathogenic Paediatric Bacterial Meningitis in Mozambique: The Critical Role of Multiplex Real-Time Polymerase Chain Reaction to Estimate the Burden of Disease

    PubMed Central

    Nhantumbo, Aquino Albino; Cantarelli, Vlademir Vicente; Caireão, Juliana; Munguambe, Alcides Moniz; Comé, Charlotte Elizabeth; Pinto, Gabriela do Carmo; Zimba, Tomás Francisco; Mandomando, Inácio; Semá, Cynthia Baltazar; Dias, Cícero; Moraes, Milton Ozório; Gudo, Eduardo Samo

    2015-01-01

    Background In Sub-Saharan Africa, including Mozambique, acute bacterial meningitis (ABM) represents a main cause of childhood mortality. The burden of ABM is seriously underestimated because of the poor performance of culture sampling, the primary method of ABM surveillance in the region. Low quality cerebrospinal fluid (CSF) samples and frequent consumption of antibiotics prior to sample collection lead to a high rate of false-negative results. To our knowledge, this study is the first to determine the frequency of ABM in Mozambique using real-time polymerase chain reaction (qPCR) and to compare results to those of culture sampling. Method Between March 2013 and March 2014, CSF samples were collected at 3 regional hospitals from patients under 5 years of age, who met World Health Organization case definition criteria for ABM. Macroscopic examination, cytochemical study, culture, and qPCR were performed on all samples. Results A total of 369 CSF samples were collected from children clinically suspected of ABM. qPCR showed a significantly higher detection rate of ABM-causing pathogens when compared to culture (52.3% [193/369] versus 7.3% [27/369], p = 0.000). The frequency of Streptococcus pneumoniae, Haemophilus influenzae, group B Streptococci, and Neisseria meningitidis were 32.8% (121⁄369), 12.2%, (45⁄369), 3.0% (16⁄369) and 4.3% (11⁄369), respectively, significantly higher compared to that obtained on culture (p < 0.001 for each). Conclusion Our findings demonstrate that culture is less effective for the diagnosis of ABM than qPCR. The common use of culture rather than qPCR to identify ABM results in serious underestimation of the burden of the disease, and our findings strongly suggest that qPCR should be incorporated into surveillance activities for ABM. In addition, our data showed that S. pneumoniae represents the most common cause of ABM in children under 5 years of age. PMID:26393933

  4. REAL TIME SYSTEM OPERATIONS 2006-2007

    SciTech Connect

    Eto, Joseph H.; Parashar, Manu; Lewis, Nancy Jo

    2008-08-15

    The Real Time System Operations (RTSO) 2006-2007 project focused on two parallel technical tasks: (1) Real-Time Applications of Phasors for Monitoring, Alarming and Control; and (2) Real-Time Voltage Security Assessment (RTVSA) Prototype Tool. The overall goal of the phasor applications project was to accelerate adoption and foster greater use of new, more accurate, time-synchronized phasor measurements by conducting research and prototyping applications on California ISO's phasor platform - Real-Time Dynamics Monitoring System (RTDMS) -- that provide previously unavailable information on the dynamic stability of the grid. Feasibility assessment studies were conducted on potential application of this technology for small-signal stability monitoring, validating/improving existing stability nomograms, conducting frequency response analysis, and obtaining real-time sensitivity information on key metrics to assess grid stress. Based on study findings, prototype applications for real-time visualization and alarming, small-signal stability monitoring, measurement based sensitivity analysis and frequency response assessment were developed, factory- and field-tested at the California ISO and at BPA. The goal of the RTVSA project was to provide California ISO with a prototype voltage security assessment tool that runs in real time within California ISO?s new reliability and congestion management system. CERTS conducted a technical assessment of appropriate algorithms, developed a prototype incorporating state-of-art algorithms (such as the continuation power flow, direct method, boundary orbiting method, and hyperplanes) into a framework most suitable for an operations environment. Based on study findings, a functional specification was prepared, which the California ISO has since used to procure a production-quality tool that is now a part of a suite of advanced computational tools that is used by California ISO for reliability and congestion management.

  5. Real time analysis of voiced sounds

    NASA Technical Reports Server (NTRS)

    Hong, J. P. (Inventor)

    1976-01-01

    A power spectrum analysis of the harmonic content of a voiced sound signal is conducted in real time by phase-lock-loop tracking of the fundamental frequency, (f sub 0) of the signal and successive harmonics (h sub 1 through h sub n) of the fundamental frequency. The analysis also includes measuring the quadrature power and phase of each frequency tracked, differentiating the power measurements of the harmonics in adjacent pairs, and analyzing successive differentials to determine peak power points in the power spectrum for display or use in analysis of voiced sound, such as for voice recognition.

  6. Time-Frequency Feature Representation Using Multi-Resolution Texture Analysis and Acoustic Activity Detector for Real-Life Speech Emotion Recognition

    PubMed Central

    Wang, Kun-Ching

    2015-01-01

    The classification of emotional speech is mostly considered in speech-related research on human-computer interaction (HCI). In this paper, the purpose is to present a novel feature extraction based on multi-resolutions texture image information (MRTII). The MRTII feature set is derived from multi-resolution texture analysis for characterization and classification of different emotions in a speech signal. The motivation is that we have to consider emotions have different intensity values in different frequency bands. In terms of human visual perceptual, the texture property on multi-resolution of emotional speech spectrogram should be a good feature set for emotion classification in speech. Furthermore, the multi-resolution analysis on texture can give a clearer discrimination between each emotion than uniform-resolution analysis on texture. In order to provide high accuracy of emotional discrimination especially in real-life, an acoustic activity detection (AAD) algorithm must be applied into the MRTII-based feature extraction. Considering the presence of many blended emotions in real life, in this paper make use of two corpora of naturally-occurring dialogs recorded in real-life call centers. Compared with the traditional Mel-scale Frequency Cepstral Coefficients (MFCC) and the state-of-the-art features, the MRTII features also can improve the correct classification rates of proposed systems among different language databases. Experimental results show that the proposed MRTII-based feature information inspired by human visual perception of the spectrogram image can provide significant classification for real-life emotional recognition in speech. PMID:25594590

  7. A real scale simulator for high frequency LEMP

    NASA Technical Reports Server (NTRS)

    Gauthier, D.; Serafin, D.

    1991-01-01

    The real scale simulator is described which was designed by the Centre d'Etudes de Gramat (CEG) to study the coupling of fast rise time Lightning Electromagnetic pulse in a fighter aircraft. The system capability of generating the right electromagnetic environment was studied using a Finite Difference Time Domain (FDTD) computer program. First, data of inside stresses are shown. Then, a time domain and a frequency domain approach is exposed and compared.

  8. Real Time Sonic Boom Display

    NASA Technical Reports Server (NTRS)

    Haering, Ed

    2014-01-01

    This presentation will provide general information about sonic boom mitigation technology to the public in order to supply information to potential partners and licensees. The technology is a combination of flight data, atmospheric data and terrain information implemented into a control room real time display for flight planning. This research is currently being performed and as such, any results and conclusions are ongoing.

  9. Real Time Data System (RTDS)

    NASA Technical Reports Server (NTRS)

    Heindel, Troy A.

    1991-01-01

    Information is given in viewgraph form on the Real Time Data System (RTDS). Topics covered include applications to the Space Station Freedom, the Space Shuttle flight controllers, the Mission Control Center workstations, and the Remote Manipulator Systems (RMS). Also covered are the technology gap, pacing factors, and lessons learned during research.

  10. Real Time Data System (RTDS)

    NASA Technical Reports Server (NTRS)

    Heindel, Troy A.

    1991-01-01

    Information is given in viewgraph form on the Real Time Data System (RTDS). The goals are to increase the quality of flight decision making, reduce and enhance flight controller training time, and serve as a near-operations technology test-bed. Information is given on the growth of RTDS; flight control disciplines; RTDS technology deployment in 1987-1989 and 1990-91; a functionality comparison of mainframes and workstations; and technology transfer activities.

  11. [Real time 3D echocardiography].

    PubMed

    Bauer, F; Shiota, T; Thomas, J D

    2001-07-01

    Three-dimensional representation of the heart is an old concern. Usually, 3D reconstruction of the cardiac mass is made by successive acquisition of 2D sections, the spatial localisation and orientation of which require complex guiding systems. More recently, the concept of volumetric acquisition has been introduced. A matricial emitter-receiver probe complex with parallel data processing provides instantaneous of a pyramidal 64 degrees x 64 degrees volume. The image is restituted in real time and is composed of 3 planes (planes B and C) which can be displaced in all spatial directions at any time during acquisition. The flexibility of this system of acquisition allows volume and mass measurement with greater accuracy and reproducibility, limiting inter-observer variability. Free navigation of the planes of investigation allows reconstruction for qualitative and quantitative analysis of valvular heart disease and other pathologies. Although real time 3D echocardiography is ready for clinical usage, some improvements are still necessary to improve its conviviality. Then real time 3D echocardiography could be the essential tool for understanding, diagnosis and management of patients. PMID:11494630

  12. [Real time 3D echocardiography

    NASA Technical Reports Server (NTRS)

    Bauer, F.; Shiota, T.; Thomas, J. D.

    2001-01-01

    Three-dimensional representation of the heart is an old concern. Usually, 3D reconstruction of the cardiac mass is made by successive acquisition of 2D sections, the spatial localisation and orientation of which require complex guiding systems. More recently, the concept of volumetric acquisition has been introduced. A matricial emitter-receiver probe complex with parallel data processing provides instantaneous of a pyramidal 64 degrees x 64 degrees volume. The image is restituted in real time and is composed of 3 planes (planes B and C) which can be displaced in all spatial directions at any time during acquisition. The flexibility of this system of acquisition allows volume and mass measurement with greater accuracy and reproducibility, limiting inter-observer variability. Free navigation of the planes of investigation allows reconstruction for qualitative and quantitative analysis of valvular heart disease and other pathologies. Although real time 3D echocardiography is ready for clinical usage, some improvements are still necessary to improve its conviviality. Then real time 3D echocardiography could be the essential tool for understanding, diagnosis and management of patients.

  13. Real-time ultrasound elastography

    NASA Astrophysics Data System (ADS)

    Bae, Unmin; Kim, Yongmin

    2007-03-01

    Ultrasound elastography can provide tissue stiffness information that is complementary to the anatomy and blood flow information offered by conventional ultrasound machines, but it is computationally challenging due to many time-consuming modules and a large amount of data. To facilitate real-time implementations of ultrasound elastography, we have developed new methods that can significantly reduce the computational burden of common processing components in ultrasound elastography, such as the crosscorrelation analysis and spatial filtering applied to displacement and strain estimates. Using the new correlation-based search algorithm, the computational requirement of correlation-based search does not increase with the correlation window size. For typical parameters used in ultrasound elastography, the computation in correlation-based search can be reduced by a factor of more than 30. Median filtering is often performed to suppress the spike-like noise that results from correlation-based search. For fast median filtering, we have developed a method that efficiently finds a new median value utilizing the sort result of the previous pixel. With careful mapping of the new algorithms on digital signal processors, our work has led to development of a clinical ultrasound machine supporting real-time elastography. Our methods can help real-time implementations of various applications including ultrasound elastography, which could lead to increased use of ultrasound elastography in the clinic.

  14. Real-time optical image processing techniques

    NASA Technical Reports Server (NTRS)

    Liu, Hua-Kuang

    1988-01-01

    Nonlinear real-time optical processing on spatial pulse frequency modulation has been pursued through the analysis, design, and fabrication of pulse frequency modulated halftone screens and the modification of micro-channel spatial light modulators (MSLMs). Micro-channel spatial light modulators are modified via the Fabry-Perot method to achieve the high gamma operation required for non-linear operation. Real-time nonlinear processing was performed using the halftone screen and MSLM. The experiments showed the effectiveness of the thresholding and also showed the needs of higher SBP for image processing. The Hughes LCLV has been characterized and found to yield high gamma (about 1.7) when operated in low frequency and low bias mode. Cascading of two LCLVs should also provide enough gamma for nonlinear processing. In this case, the SBP of the LCLV is sufficient but the uniformity of the LCLV needs improvement. These include image correlation, computer generation of holograms, pseudo-color image encoding for image enhancement, and associative-retrieval in neural processing. The discovery of the only known optical method for dynamic range compression of an input image in real-time by using GaAs photorefractive crystals is reported. Finally, a new architecture for non-linear multiple sensory, neural processing has been suggested.

  15. Real-time tritium imaging

    SciTech Connect

    Malinowski, M.E.

    1981-09-15

    A real-time image of a tritium-containing titanium film has been made by detecting the secondary electrons produced by tritium ..beta.. decay with a simple two-element electrostatic lens and microchannel plate image intensifier. The obtained image indicates that a resolution of better than 100 ..mu..m is currently obtainable and suggests that image magnification to enhance resolution should be possible.

  16. Abstraction Planning in Real Time

    NASA Technical Reports Server (NTRS)

    Washington, Richard

    1994-01-01

    When a planning agent works in a complex, real-world domain, it is unable to plan for and store all possible contingencies and problem situations ahead of time. The agent needs to be able to fall back on an ability to construct plans at run time under time constraints. This thesis presents a method for planning at run time that incrementally builds up plans at multiple levels of abstraction. The plans are continually updated by information from the world, allowing the planner to adjust its plan to a changing world during the planning process. All the information is represented over intervals of time, allowing the planner to reason about durations, deadlines, and delays within its plan. In addition to the method, the thesis presents a formal model of the planning process and uses the model to investigate planning strategies. The method has been implemented, and experiments have been run to validate the overall approach and the theoretical model.

  17. Real-time flutter analysis

    NASA Technical Reports Server (NTRS)

    Walker, R.; Gupta, N.

    1984-01-01

    The important algorithm issues necessary to achieve a real time flutter monitoring system; namely, the guidelines for choosing appropriate model forms, reduction of the parameter convergence transient, handling multiple modes, the effect of over parameterization, and estimate accuracy predictions, both online and for experiment design are addressed. An approach for efficiently computing continuous-time flutter parameter Cramer-Rao estimate error bounds were developed. This enables a convincing comparison of theoretical and simulation results, as well as offline studies in preparation for a flight test. Theoretical predictions, simulation and flight test results from the NASA Drones for Aerodynamic and Structural Test (DAST) Program are compared.

  18. Characterization of a Novel Melt Curve by Use of the Roche LightCycler HSV 1/2 Analyte-Specific Reagent Real-Time PCR Assay: Frequencies of This Novel (Low) Melt Curve and Commonly Encountered (Intermediate) Melt Curves

    PubMed Central

    Almradi, Amro; Espy, Mark J.; Prada, Anne E.; Gibson, John P.; Pritt, Bobbi S.

    2014-01-01

    We characterize a novel probe binding-site polymorphism detectable solely by melt curve analysis using the Roche LightCycler HSV 1/2 analyte-specific reagent real-time PCR assay. The frequencies of this novel (47°C) and previously described intermediate (60 to 62°C) melt curves were 0.016% and 4.9%, respectively. PMID:24352998

  19. Abstraction Planning in Real Time

    NASA Technical Reports Server (NTRS)

    Washington, R.

    1994-01-01

    When a planning agent works in a complex, real-world domain, it is unable to plan for and store all possible contingencies and problem situations ahead of time. This thesis presents a method for planning a run time that incrementally builds up plans at multiple levels of abstraction. The plans are continually updated by information from the world, allowing the planner to adjust its plan to a changing world during the planning process. All the information is represented over intervals of time, allowing the planner to reason about durations, deadlines, and delays within its plan. In addition to the method, the thesis presents a formal model of the planning process and uses the model to investigate planning strategies.

  20. Real-time streamflow conditions

    USGS Publications Warehouse

    Graczyk, David J.; Gebert, Warren A.

    1996-01-01

    Would you like to know streamflow conditions before you go fishing in Wisconsin or in more distant locations? Real-time streamflow data throughout Wisconsin and the United States are available on the Internet from the U.S. Geological Survey. You can see if the stream you are interested in fishing is high due to recent rain or low because of an extended dry spell. Flow conditions at more than 100 stream-gaging stations located throughout Wisconsin can be viewed by accessing the Wisconsin District Home Page at: http://wwwdwimdn.er.usgs.gov

  1. Real time infrared aerosol analyzer

    DOEpatents

    Johnson, Stanley A.; Reedy, Gerald T.; Kumar, Romesh

    1990-01-01

    Apparatus for analyzing aerosols in essentially real time includes a virtual impactor which separates coarse particles from fine and ultrafine particles in an aerosol sample. The coarse and ultrafine particles are captured in PTFE filters, and the fine particles impact onto an internal light reflection element. The composition and quantity of the particles on the PTFE filter and on the internal reflection element are measured by alternately passing infrared light through the filter and the internal light reflection element, and analyzing the light through infrared spectrophotometry to identify the particles in the sample.

  2. Real time speech formant analyzer and display

    DOEpatents

    Holland, George E.; Struve, Walter S.; Homer, John F.

    1987-01-01

    A speech analyzer for interpretation of sound includes a sound input which converts the sound into a signal representing the sound. The signal is passed through a plurality of frequency pass filters to derive a plurality of frequency formants. These formants are converted to voltage signals by frequency-to-voltage converters and then are prepared for visual display in continuous real time. Parameters from the inputted sound are also derived and displayed. The display may then be interpreted by the user. The preferred embodiment includes a microprocessor which is interfaced with a television set for displaying of the sound formants. The microprocessor software enables the sound analyzer to present a variety of display modes for interpretive and therapeutic used by the user.

  3. Real time speech formant analyzer and display

    DOEpatents

    Holland, G.E.; Struve, W.S.; Homer, J.F.

    1987-02-03

    A speech analyzer for interpretation of sound includes a sound input which converts the sound into a signal representing the sound. The signal is passed through a plurality of frequency pass filters to derive a plurality of frequency formants. These formants are converted to voltage signals by frequency-to-voltage converters and then are prepared for visual display in continuous real time. Parameters from the inputted sound are also derived and displayed. The display may then be interpreted by the user. The preferred embodiment includes a microprocessor which is interfaced with a television set for displaying of the sound formants. The microprocessor software enables the sound analyzer to present a variety of display modes for interpretive and therapeutic used by the user. 19 figs.

  4. Real-time analysis keratometer

    NASA Technical Reports Server (NTRS)

    Adachi, Iwao P. (Inventor); Adachi, Yoshifumi (Inventor); Frazer, Robert E. (Inventor)

    1987-01-01

    A computer assisted keratometer in which a fiducial line pattern reticle illuminated by CW or pulsed laser light is projected on a corneal surface through lenses, a prismoidal beamsplitter quarterwave plate, and objective optics. The reticle surface is curved as a conjugate of an ideal corneal curvature. The fiducial image reflected from the cornea undergoes a polarization shift through the quarterwave plate and beamsplitter whereby the projected and reflected beams are separated and directed orthogonally. The reflected beam fiducial pattern forms a moire pattern with a replica of the first recticle. This moire pattern contains transverse aberration due to differences in curvature between the cornea and the ideal corneal curvature. The moire pattern is analyzed in real time by computer which displays either the CW moire pattern or a pulsed mode analysis of the transverse aberration of the cornea under observation, in real time. With the eye focused on a plurality of fixation points in succession, a survey of the entire corneal topography is made and a contour map or three dimensional plot of the cornea can be made as a computer readout in addition to corneal radius and refractive power analysis.

  5. Real-time flood forecasting

    USGS Publications Warehouse

    Lai, C.; Tsay, T.-K.; Chien, C.-H.; Wu, I.-L.

    2009-01-01

    Researchers at the Hydroinformatic Research and Development Team (HIRDT) of the National Taiwan University undertook a project to create a real time flood forecasting model, with an aim to predict the current in the Tamsui River Basin. The model was designed based on deterministic approach with mathematic modeling of complex phenomenon, and specific parameter values operated to produce a discrete result. The project also devised a rainfall-stage model that relates the rate of rainfall upland directly to the change of the state of river, and is further related to another typhoon-rainfall model. The geographic information system (GIS) data, based on precise contour model of the terrain, estimate the regions that were perilous to flooding. The HIRDT, in response to the project's progress, also devoted their application of a deterministic model to unsteady flow of thermodynamics to help predict river authorities issue timely warnings and take other emergency measures.

  6. Relationship of Imaging Frequency and Planning Margin to Account for Intrafraction Prostate Motion: Analysis Based on Real-Time Monitoring Data

    SciTech Connect

    Curtis, William; Khan, Mohammad; Magnelli, Anthony; Stephans, Kevin; Tendulkar, Rahul; Xia, Ping

    2013-03-01

    Purpose: Correction for intrafraction prostate motion becomes important for hypofraction treatment of prostate cancer. The purpose of this study was to estimate an ideal planning margin to account for intrafraction prostate motion as a function of imaging and repositioning frequency in the absence of continuous prostate motion monitoring. Methods and Materials: For 31 patients receiving intensity modulated radiation therapy treatment, prostate positions sampled at 10 Hz during treatment using the Calypso system were analyzed. Using these data, we simulated multiple, less frequent imaging protocols, including intervals of every 10, 15, 20, 30, 45, 60, 90, 120, 180, and 240 seconds. For each imaging protocol, the prostate displacement at the imaging time was corrected by subtracting prostate shifts from the subsequent displacements in that fraction. Furthermore, we conducted a principal component analysis to quantify the direction of prostate motion. Results: Averaging histograms of every 240 and 60 seconds for all patients, vector displacements of the prostate were, respectively, within 3 and 2 mm for 95% of the treatment time. A vector margin of 1 mm achieved 91.2% coverage of the prostate with 30 second imaging. The principal component analysis for all fractions showed the largest variance in prostate position in the midsagittal plane at 54° from the anterior direction, indicating that anterosuperior to inferoposterior is the direction of greatest motion. The smallest prostate motion is in the left-right direction. Conclusions: The magnitudes of intrafraction prostate motion along the superior-inferior and anterior-posterior directions are comparable, and the smallest motion is in the left-right direction. In the absence of continuous prostate motion monitoring, and under ideal circumstances, 1-, 2-, and 3-mm vector planning margins require a respective imaging frequency of every 15, 60, and 240 to account for intrafraction prostate motion while achieving

  7. Gabor: frequency, time, and memory.

    PubMed

    Korpel, A

    1982-10-15

    Dennis Gabor is well-known as the inventor of holography. Less well-known, perhaps, are his contributions to other areas. Yet they are important and, like holography, characteristic of his foresight. In the field of communications, Gabor investigated the classic dichotomy of time and frequency. Guided by analogies to quantum mechanics, he postulated a set of elementary signals and made brilliant use of time-frequency diagrams to analyze communication systems. Applying his theories to acoustics, he researched the mechanism of hearing, defining acoustical quanta in the process and inventing early prototype frequency compressors and expanders. In a completely different field, Gabor, inspired by some early work of Longuet-Higgins on models for holographic temporal recall in the brain, suggested novel approaches which contributed significantly to the understanding of associative memories. In this paper we describe Gabor's pioneering work in these areas and trace the subsequent development by himself and others. PMID:20396288

  8. Autonomous Real Time Requirements Tracing

    NASA Technical Reports Server (NTRS)

    Plattsmier, George I.; Stetson, Howard K.

    2014-01-01

    One of the more challenging aspects of software development is the ability to verify and validate the functional software requirements dictated by the Software Requirements Specification (SRS) and the Software Detail Design (SDD). Insuring the software has achieved the intended requirements is the responsibility of the Software Quality team and the Software Test team. The utilization of Timeliner-TLX(sup TM) Auto-Procedures for relocating ground operations positions to ISS automated on-board operations has begun the transition that would be required for manned deep space missions with minimal crew requirements. This transition also moves the auto-procedures from the procedure realm into the flight software arena and as such the operational requirements and testing will be more structured and rigorous. The autoprocedures would be required to meet NASA software standards as specified in the Software Safety Standard (NASASTD- 8719), the Software Engineering Requirements (NPR 7150), the Software Assurance Standard (NASA-STD-8739) and also the Human Rating Requirements (NPR-8705). The Autonomous Fluid Transfer System (AFTS) test-bed utilizes the Timeliner-TLX(sup TM) Language for development of autonomous command and control software. The Timeliner- TLX(sup TM) system has the unique feature of providing the current line of the statement in execution during real-time execution of the software. The feature of execution line number internal reporting unlocks the capability of monitoring the execution autonomously by use of a companion Timeliner-TLX(sup TM) sequence as the line number reporting is embedded inside the Timeliner-TLX(sup TM) execution engine. This negates I/O processing of this type data as the line number status of executing sequences is built-in as a function reference. This paper will outline the design and capabilities of the AFTS Autonomous Requirements Tracker, which traces and logs SRS requirements as they are being met during real-time execution of the

  9. Autonomous Real Time Requirements Tracing

    NASA Technical Reports Server (NTRS)

    Plattsmier, George; Stetson, Howard

    2014-01-01

    One of the more challenging aspects of software development is the ability to verify and validate the functional software requirements dictated by the Software Requirements Specification (SRS) and the Software Detail Design (SDD). Insuring the software has achieved the intended requirements is the responsibility of the Software Quality team and the Software Test team. The utilization of Timeliner-TLX(sup TM) Auto- Procedures for relocating ground operations positions to ISS automated on-board operations has begun the transition that would be required for manned deep space missions with minimal crew requirements. This transition also moves the auto-procedures from the procedure realm into the flight software arena and as such the operational requirements and testing will be more structured and rigorous. The autoprocedures would be required to meet NASA software standards as specified in the Software Safety Standard (NASASTD- 8719), the Software Engineering Requirements (NPR 7150), the Software Assurance Standard (NASA-STD-8739) and also the Human Rating Requirements (NPR-8705). The Autonomous Fluid Transfer System (AFTS) test-bed utilizes the Timeliner-TLX(sup TM) Language for development of autonomous command and control software. The Timeliner-TLX(sup TM) system has the unique feature of providing the current line of the statement in execution during real-time execution of the software. The feature of execution line number internal reporting unlocks the capability of monitoring the execution autonomously by use of a companion Timeliner-TLX(sup TM) sequence as the line number reporting is embedded inside the Timeliner-TLX(sup TM) execution engine. This negates I/O processing of this type data as the line number status of executing sequences is built-in as a function reference. This paper will outline the design and capabilities of the AFTS Autonomous Requirements Tracker, which traces and logs SRS requirements as they are being met during real-time execution of the

  10. Precision frequency synthesizing sources with excellent time/frequency performances

    NASA Technical Reports Server (NTRS)

    Zhou, Liren; Lin, Hai

    1994-01-01

    Precision frequency synthesizing sources are needed in the time / frequency measuring system, atomic frequency standards, telemetry, communication, and radar systems. This kind of frequency synthesizing source possesses high frequency accuracy and excellent long term and short term frequency stability. Several precision frequency synthesizing sources developed by Beijing Institute of Radio Metrology and Measurement (BIRMM) which have been successfully applied to the time / frequency measuring system, atomic frequency standards system, and radar system are described. In addition, the working principle, implementation approach, and the main technical specifications of the frequency synthesizing sources are also given.

  11. MISR Level 1 Near Real Time Products

    Atmospheric Science Data Center

    2014-09-15

    Level 1 Near Real Time The MISR Near Real Time Level 1 data products consist of radiance measurements organized in 10-50 minute ... (off-nadir) cameras. The remaining channels are sampled at 1.1 km. ...

  12. On the detection of acoustic-gravity waves generated by typhoon by use of real time HF Doppler frequency shift sounding system

    NASA Astrophysics Data System (ADS)

    Huang, Yinn-Nien; Cheng, Kang; Chen, Sen-Wen

    1985-07-01

    A development of a direct vision type high-frequency Doppler frequency sounder and a setup of HF Doppler frequency sounding array at the northern part of Taiwan Island were presented. By use of all typhoons that occurred in 1982 and 1983, the detectability of the typhoon-generated acoustic-gravity waves by use of this HF Doppler frequency sounding array was presented. The results show that the acoustic-gravity waves generated by a typhoon can be detected by this sounding array; however, the detectability is only 2 out of 12.

  13. Real-Time Data Display

    NASA Technical Reports Server (NTRS)

    Pedings, Marc

    2007-01-01

    RT-Display is a MATLAB-based data acquisition environment designed to use a variety of commercial off-the-shelf (COTS) hardware to digitize analog signals to a standard data format usable by other post-acquisition data analysis tools. This software presents the acquired data in real time using a variety of signal-processing algorithms. The acquired data is stored in a standard Operator Interactive Signal Processing Software (OISPS) data-formatted file. RT-Display is primarily configured to use the Agilent VXI (or equivalent) data acquisition boards used in such systems as MIDDAS (Multi-channel Integrated Dynamic Data Acquisition System). The software is generalized and deployable in almost any testing environment, without limitations or proprietary configuration for a specific test program or project. With the Agilent hardware configured and in place, users can start the program and, in one step, immediately begin digitizing multiple channels of data. Once the acquisition is completed, data is converted into a common binary format that also can be translated to specific formats used by external analysis software, such as OISPS and PC-Signal (product of AI Signal Research Inc.). RT-Display at the time of this reporting was certified on Agilent hardware capable of acquisition up to 196,608 samples per second. Data signals are presented to the user on-screen simultaneously for 16 channels. Each channel can be viewed individually, with a maximum capability of 160 signal channels (depending on hardware configuration). Current signal presentations include: time data, fast Fourier transforms (FFT), and power spectral density plots (PSD). Additional processing algorithms can be easily incorporated into this environment.

  14. Mobile real time radiography system

    SciTech Connect

    Vigil, J.; Taggart, D.; Betts, S.

    1997-11-01

    A 450-keV Mobile Real Time Radiography (RTR) System was delivered to Los Alamos National Laboratory (LANL) in January 1996. It was purchased to inspect containers of radioactive waste produced at (LANL). Since its delivery it has been used to radiograph more than 600 drums of radioactive waste at various LANL sites. It has the capability of inspecting waste containers of various sizes from <1-gal. buckets up to standard waste boxes (SWB, dimensions 54.5 in. x 71 in. x 37 in.). It has three independent x-ray acquisition formats. The primary system used is a 12- in. image intensifier, the second is a 36-in. linear diode array (LDA) and the last is an open system. It is fully self contained with on board generator, HVAC, and a fire suppression system. It is on a 53-ft long x 8-ft. wide x 14-ft. high trailer that can be moved over any highway requiring only an easily obtainable overweight permit because it weights {approximately}38 tons. It was built to conform to industry standards for a cabinet system which does not require an exclusion zone. The fact that this unit is mobile has allowed us to operate where the waste is stored, rather than having to move the waste to a fixed facility.

  15. Passive Global, Real-Time TEC Monitoring

    NASA Astrophysics Data System (ADS)

    Pongratz, M. B.

    2002-12-01

    Sensors are being developed to provide a satellite-based VHF global lightning monitor (e.g. Suszcynsky, et al., "VHF Global Lightning and Severe Storm Monitoring from Space: Storm-level Characterization of VHF Lightning Emissions," EOS Trans. AGU 2001 Fall Mt. Prog. And Abstr. 82, No. 47, F143, 2001). Dispersive effects of propagation of the lightning electromagnetic wave through the ionospheric and plasmaspheric plasmas cause the higher frequency components to arrive at the satellite before lower frequency components. From the time-of-arrival at several frequencies we can derive the TEC between the satellite and the lightning. Using multi-satellite techniques we can geolocate the lightning and the ionospheric penetration point quite accurately. A single ground station could provide essentially real-time regional TEC coverage. Four ground stations could provide global, real-time TEC measurements to supplement existing ground-based systems, especially over broad ocean areas. We expect several lightning detections per satellite per minute. Temporal resolution will be limited only by ground segment processing. Spatial coverage and resolution will be limited by lightning occurrence, but many commercial sector TEC requirements are also correlated to lightning occurrence. With our FORTE (Fast On-orbit Recording of Transient Events) satellite we sense lightning over most of the globe including the oceans. We expect to determine TEC spatial gradients with tens of km resolution. This capability should be especially useful in severe convective weather to aircraft using GPS-based navigation, e.g. the FAA's Wide Area Augmentation System (WAAS).

  16. Students Collecting Real time Data

    NASA Astrophysics Data System (ADS)

    Miller, P.

    2006-05-01

    Students Collecting Real-Time Data The Hawaiian Islands Humpback Whale National Marine Sanctuary has created opportunities for middle and high school students to become Student Researchers and to be involved in real-time marine data collection. It is important that we expose students to different fields of science and encourage them to enter scientific fields of study. The Humpback Whale Sanctuary has an education visitor center in Kihei, Maui. Located right on the beach, the site has become a living classroom facility. There is a traditional Hawaiian fishpond fronting the property. The fishpond wall is being restored, using traditional methods. The site has the incredible opportunity of incorporating Hawaiian cultural practices with scientific studies. The Sanctuary offers opportunities for students to get involved in monitoring and data collection studies. Invasive Seaweed Study: Students are collecting data on invasive seaweed for the University of Hawaii. They pull a large net through the shallow waters. Seaweed is sorted, identified and weighed. The invasive seaweeds are removed. The data is recorded and sent to UH. Remote controlled monitoring boats: The sanctuary has 6 boogie board sized remote controlled boats used to monitor reefs. Boats have a camera with lights on the underside. The boats have water quality monitoring devices and GPS units. The video from the underwater camera is transmitted via a wireless transmission. Students are able to monitor the fish, limu and invertebrate populations on the reef and collect water quality data via television monitors or computers. The boat can also pull a small plankton tow net. Data is being compiled into data bases. Artificial Reef Modules: The Sanctuary has a scientific permit from the state to build and deploy artificial reef modules. High school students are designing and building modules. These are deployed out in the Fishpond fronting the Sanctuary site and students are monitoring them on a weekly basis

  17. VERSE - Virtual Equivalent Real-time Simulation

    NASA Technical Reports Server (NTRS)

    Zheng, Yang; Martin, Bryan J.; Villaume, Nathaniel

    2005-01-01

    Distributed real-time simulations provide important timing validation and hardware in the- loop results for the spacecraft flight software development cycle. Occasionally, the need for higher fidelity modeling and more comprehensive debugging capabilities - combined with a limited amount of computational resources - calls for a non real-time simulation environment that mimics the real-time environment. By creating a non real-time environment that accommodates simulations and flight software designed for a multi-CPU real-time system, we can save development time, cut mission costs, and reduce the likelihood of errors. This paper presents such a solution: Virtual Equivalent Real-time Simulation Environment (VERSE). VERSE turns the real-time operating system RTAI (Real-time Application Interface) into an event driven simulator that runs in virtual real time. Designed to keep the original RTAI architecture as intact as possible, and therefore inheriting RTAI's many capabilities, VERSE was implemented with remarkably little change to the RTAI source code. This small footprint together with use of the same API allows users to easily run the same application in both real-time and virtual time environments. VERSE has been used to build a workstation testbed for NASA's Space Interferometry Mission (SIM PlanetQuest) instrument flight software. With its flexible simulation controls and inexpensive setup and replication costs, VERSE will become an invaluable tool in future mission development.

  18. Exploring Earthquakes in Real-Time

    NASA Astrophysics Data System (ADS)

    Bravo, T. K.; Kafka, A. L.; Coleman, B.; Taber, J. J.

    2013-12-01

    Earthquakes capture the attention of students and inspire them to explore the Earth. Adding the ability to view and explore recordings of significant and newsworthy earthquakes in real-time makes the subject even more compelling. To address this opportunity, the Incorporated Research Institutions for Seismology (IRIS), in collaboration with Moravian College, developed ';jAmaSeis', a cross-platform application that enables students to access real-time earthquake waveform data. Students can watch as the seismic waves are recorded on their computer, and can be among the first to analyze the data from an earthquake. jAmaSeis facilitates student centered investigations of seismological concepts using either a low-cost educational seismograph or streamed data from other educational seismographs or from any seismic station that sends data to the IRIS Data Management System. After an earthquake, students can analyze the seismograms to determine characteristics of earthquakes such as time of occurrence, distance from the epicenter to the station, magnitude, and location. The software has been designed to provide graphical clues to guide students in the analysis and assist in their interpretations. Since jAmaSeis can simultaneously record up to three stations from anywhere on the planet, there are numerous opportunities for student driven investigations. For example, students can explore differences in the seismograms from different distances from an earthquake and compare waveforms from different azimuthal directions. Students can simultaneously monitor seismicity at a tectonic plate boundary and in the middle of the plate regardless of their school location. This can help students discover for themselves the ideas underlying seismic wave propagation, regional earthquake hazards, magnitude-frequency relationships, and the details of plate tectonics. The real-time nature of the data keeps the investigations dynamic, and offers students countless opportunities to explore.

  19. Real Time Simulation of Power Grid Disruptions

    SciTech Connect

    Chinthavali, Supriya; Dimitrovski, Aleksandar D; Fernandez, Steven J; Groer, Christopher S; Nutaro, James J; Olama, Mohammed M; Omitaomu, Olufemi A; Shankar, Mallikarjun; Spafford, Kyle L; Vacaliuc, Bogdan

    2012-11-01

    DOE-OE and DOE-SC workshops (Reference 1-3) identified the key power grid problem that requires insight addressable by the next generation of exascale computing is coupling of real-time data streams (1-2 TB per hour) as the streams are ingested to dynamic models. These models would then identify predicted disruptions in time (2-4 seconds) to trigger the smart grid s self healing functions. This project attempted to establish the feasibility of this approach and defined the scientific issues, and demonstrated example solutions to important smart grid simulation problems. These objectives were accomplished by 1) using the existing frequency recorders on the national grid to establish a representative and scalable real-time data stream; 2) invoking ORNL signature identification algorithms; 3) modeling dynamically a representative region of the Eastern interconnect using an institutional cluster, measuring the scalability and computational benchmarks for a national capability; and 4) constructing a prototype simulation for the system s concept of smart grid deployment. The delivered ORNL enduring capability included: 1) data processing and simulation metrics to design a national capability justifying exascale applications; 2) Software and intellectual property built around the example solutions; 3) demonstrated dynamic models to design few second self-healing.

  20. A Real-Time Nonvolatile Residue (NVR) Monitor

    NASA Technical Reports Server (NTRS)

    Bowers, William D.; Chuan, Raymond L.

    1995-01-01

    New development and application of device described in "Surface-Acoustic-Wave Piezoelectric Microbalance," (LAR-14476). Active sensing element of Real-Time NVR Monitor comprises pair of piezoelectric surface-acoustic-wave resonators resonating at frequency of 200 MHz. Bare, uncoated resonator exposed to atmosphere and directly in contact with airborne volatile and nonvolatile materials leaving residues on surface. Resonant frequency of exposed resonator decreases with increasing mass of adsorbed residue; resulting beat frequency between two resonators increases with mass and serves as sensitive real-time indication of airborne contaminants or non-volatile residue.

  1. High sensitivity real-time NVR monitor

    NASA Technical Reports Server (NTRS)

    Bowers, William D. (Inventor); Chuan, Raymond L. (Inventor)

    1997-01-01

    A real time non-volatile residue (NVR) monitor, which utilizes surface acoustic wave (SAW) resonators to detect molecular contamination in a given environment. The SAW resonators operate at a resonant frequency of approximately 200 MHz-2,000 MHz which enables the NVR monitor to detect molecular contamination on the order of 10.sup.-11 g-cm.sup.-2 to 10.sup.-13 g-cm.sup.2. The NVR monitor utilizes active temperature control of (SAW) resonators to achieve a stable resonant frequency. The temperature control system of the NVR monitor is able to directly heat and cool the SAW resonators utilizing a thermoelectric element to maintain the resonators at a present temperature independent of the environmental conditions. In order to enable the direct heating and cooling of the SAW resonators, the SAW resonators are operatively mounted to a heat sink. In one embodiment, the heat sink is located in between the SAW resonators and an electronic circuit board which contains at least a portion of the SAW control electronics. The electrical leads of the SAW resonators are connected through the heat sink to the circuit board via an electronic path which prevents inaccurate frequency measurement.

  2. Real-time Raman sensing without spectrometer

    NASA Astrophysics Data System (ADS)

    Kim, Min Ju; Kim, Sungho; Yang, Timothy K.; Kumar, Dinesh; Bae, Sung Chul

    2015-03-01

    Raman spectroscopy has been a powerful tool in various fields of science and technology ranging from analytical chemistry to biomedical imaging. In spite of unique features, Raman spectroscopy has also some limitations. Among them are weak Raman signal compared to strong fluorescence and relatively complicated setup with expensive and bulky spectrometer. In order to increase the sensitivity of Raman technique, many clever attempts have been made and some of them were very successful including CARS, SRS, and so on. However, these still requires expensive and more complicated setup. In this work, we have attempted to build a real-time compact Raman sensor without spectrometer. Conventional spectrometer was replaced with a narrow-band optical filter and alternatively modulated two lasers with slightly different wavelengths. At one laser, Raman signal from a target molecule was transmitted through the optical filter. At the other laser, this signal was blocked by the optical filter and could not be detected by photon detector. The alternative modulation of two lasers will modulate the Raman signal from a target molecule at the same modulation frequency. This modulated weak Raman signal was amplified by a lock-in amplifier. The advantages of this setup include compactness, low cost, real-time monitoring, and so on. We have tested the sensitivity of this setup and we found that it doesn't have enough sensitivity to detect single molecule-level, but it is still good enough to monitor the change of major chemical composition in the sample.

  3. Research in Distributed Real-Time Systems

    NASA Technical Reports Server (NTRS)

    Mukkamala, R.

    1997-01-01

    This document summarizes the progress we have made on our study of issues concerning the schedulability of real-time systems. Our study has produced several results in the scalability issues of distributed real-time systems. In particular, we have used our techniques to resolve schedulability issues in distributed systems with end-to-end requirements. During the next year (1997-98), we propose to extend the current work to address the modeling and workload characterization issues in distributed real-time systems. In particular, we propose to investigate the effect of different workload models and component models on the design and the subsequent performance of distributed real-time systems.

  4. Real time programming environment for Windows

    SciTech Connect

    LaBelle, D.R.

    1998-04-01

    This document provides a description of the Real Time Programming Environment (RTProE). RTProE tools allow a programmer to create soft real time projects under general, multi-purpose operating systems. The basic features necessary for real time applications are provided by RTProE, leaving the programmer free to concentrate efforts on his specific project. The current version supports Microsoft Windows{trademark} 95 and NT. The tasks of real time synchronization and communication with other programs are handled by RTProE. RTProE includes a generic method for connecting a graphical user interface (GUI) to allow real time control and interaction with the programmer`s product. Topics covered in this paper include real time performance issues, portability, details of shared memory management, code scheduling, application control, Operating System specific concerns and the use of Computer Aided Software Engineering (CASE) tools. The development of RTProE is an important step in the expansion of the real time programming community. The financial costs associated with using the system are minimal. All source code for RTProE has been made publicly available. Any person with access to a personal computer, Windows 95 or NT, and C or FORTRAN compilers can quickly enter the world of real time modeling and simulation.

  5. Making real-time reactive systems reliable

    NASA Technical Reports Server (NTRS)

    Marzullo, Keith; Wood, Mark

    1990-01-01

    A reactive system is characterized by a control program that interacts with an environment (or controlled program). The control program monitors the environment and reacts to significant events by sending commands to the environment. This structure is quite general. Not only are most embedded real time systems reactive systems, but so are monitoring and debugging systems and distributed application management systems. Since reactive systems are usually long running and may control physical equipment, fault tolerance is vital. The research tries to understand the principal issues of fault tolerance in real time reactive systems and to build tools that allow a programmer to design reliable, real time reactive systems. In order to make real time reactive systems reliable, several issues must be addressed: (1) How can a control program be built to tolerate failures of sensors and actuators. To achieve this, a methodology was developed for transforming a control program that references physical value into one that tolerates sensors that can fail and can return inaccurate values; (2) How can the real time reactive system be built to tolerate failures of the control program. Towards this goal, whether the techniques presented can be extended to real time reactive systems is investigated; and (3) How can the environment be specified in a way that is useful for writing a control program. Towards this goal, whether a system with real time constraints can be expressed as an equivalent system without such constraints is also investigated.

  6. Real-Time Dynamics Monitoring System with Synchronized Phasor Measurements

    Energy Science and Technology Software Center (ESTSC)

    2005-01-01

    The Real-Time Dynamics Monitoring System is designed to monitor the dynamics within the power grid and assess the system behavior during normal and disturbance conditions. The RTDMS application was built on the Grid-3P technology platform and takes real-time information collected by Synchronized Phasor Measurement Units (PMU5) or other collection devices and transmitted to a central Phasor Data Concentrator (PDC) for monitoring grid dynamics. The data is sampled 30 times per second and is time-synchronized. Thismore » data is processed to create graphical and geographical displays to provide visualization for frequency/frequency response, voltage magnitudes and angles, voltage angle differences across critical paths as well as real and reactive power-flows on a sub-second and second basis. Software allows for monitoring, tracking, historical data archiving and electric system troubleshooting for reliability management.« less

  7. Real-time monitoring of landslides

    USGS Publications Warehouse

    Reid, Mark E.; LaHusen, Richard G.; Baum, Rex L.; Kean, Jason W.; Schulz, William H.; Highland, Lynn M.

    2012-01-01

    Landslides cause fatalities and property damage throughout the Nation. To reduce the impact from hazardous landslides, the U.S. Geological Survey develops and uses real-time and near-real-time landslide monitoring systems. Monitoring can detect when hillslopes are primed for sliding and can provide early indications of rapid, catastrophic movement. Continuous information from up-to-the-minute or real-time monitoring provides prompt notification of landslide activity, advances our understanding of landslide behavior, and enables more effective engineering and planning efforts.

  8. Real-Time Monitoring of Active Landslides

    USGS Publications Warehouse

    Reid, Mark E.; LaHusen, Richard G.; Ellis, William L.

    1999-01-01

    Landslides threaten lives and property in every State in the Nation. To reduce the risk from active landslides, the U.S. Geological Survey (USGS) develops and uses real-time landslide monitoring systems. Monitoring can detect early indications of rapid, catastrophic movement. Up-to-the-minute or real-time monitoring provides immediate notification of landslide activity, potentially saving lives and property. Continuous information from real-time monitoring also provides a better understanding of landslide behavior, enabling engineers to create more effective designs for halting landslide movement.

  9. Real time sensor for therapeutic radiation delivery

    DOEpatents

    Bliss, Mary; Craig, Richard A.; Reeder, Paul L.

    1998-01-01

    The invention is a real time sensor for therapeutic radiation. A probe is placed in or near the patient that senses in real time the dose at the location of the probe. The strength of the dose is determined by either an insertion or an exit probe. The location is determined by a series of vertical and horizontal sensing elements that gives the operator a real time read out dose location relative to placement of the patient. The increased accuracy prevents serious tissue damage to the patient by preventing overdose or delivery of a dose to a wrong location within the body.

  10. Real time sensor for therapeutic radiation delivery

    DOEpatents

    Bliss, M.; Craig, R.A.; Reeder, P.L.

    1998-01-06

    The invention is a real time sensor for therapeutic radiation. A probe is placed in or near the patient that senses in real time the dose at the location of the probe. The strength of the dose is determined by either an insertion or an exit probe. The location is determined by a series of vertical and horizontal sensing elements that gives the operator a real time read out dose location relative to placement of the patient. The increased accuracy prevents serious tissue damage to the patient by preventing overdose or delivery of a dose to a wrong location within the body. 14 figs.

  11. Monitoring apoptosis in real time.

    PubMed

    Green, Allan M; Steinmetz, Neil D

    2002-01-01

    clinical responses. A single site study in 15 subjects with 1-year follow-up has suggested that increased posttreatment Tc 99m-rh annexin uptake is associated with improved time to progression of disease and survival time. In vivo imaging of cell death may have the potential to improve the treatment of cancer patients by allowing rapid, objective, patient-by-patient assessment of the efficacy of tumor cell killing. PMID:11999952

  12. Analysis of real-time vibration data

    USGS Publications Warehouse

    Safak, E.

    2005-01-01

    In recent years, a few structures have been instrumented to provide continuous vibration data in real time, recording not only large-amplitude motions generated by extreme loads, but also small-amplitude motions generated by ambient loads. The main objective in continuous recording is to track any changes in structural characteristics, and to detect damage after an extreme event, such as an earthquake or explosion. The Fourier-based spectral analysis methods have been the primary tool to analyze vibration data from structures. In general, such methods do not work well for real-time data, because real-time data are mainly composed of ambient vibrations with very low amplitudes and signal-to-noise ratios. The long duration, linearity, and the stationarity of ambient data, however, allow us to utilize statistical signal processing tools, which can compensate for the adverse effects of low amplitudes and high noise. The analysis of real-time data requires tools and techniques that can be applied in real-time; i.e., data are processed and analyzed while being acquired. This paper presents some of the basic tools and techniques for processing and analyzing real-time vibration data. The topics discussed include utilization of running time windows, tracking mean and mean-square values, filtering, system identification, and damage detection.

  13. Real-time smart fluorescence sensor platform

    NASA Astrophysics Data System (ADS)

    Dickens, Jason E.; Vaughn, Mike S.; Taylor, Mervin; Ponstingl, Mike

    2011-06-01

    A novel compact LED array based light induced fluorescence (LIF) sensor has been developed for real-time in-line monitoring of intrinsic fluorophores in the solid and liquid state. The sensor is essential for on-the-spot, routine, and cost effective real-time analysis. The sensor is designed to provide real-time emission response along with various smart sensing parameters to ensure real-time measurement quality that is required for regulated GMP process monitoring applications. This work describes a LIF sensor tailored for solid-phase fluorometry. Fundamental figures of merit, excitation overexposure and smart sensing features required for modern process monitoring and control are discussed within the context of pharmaceutical solid-phase manufacturing and similar applications.

  14. Interferometer real time control development for SIM

    NASA Astrophysics Data System (ADS)

    Bell, Charles E.

    2003-02-01

    Real Time Control (RTC) for the Space Interferometry Mission will build on the real time core interferometer control technology under development at JPL since the mid 1990s, with heritage from the ground based MKII and Palomar Testbed Interferometer projects developed in the late '80s and early '90s. The core software and electronics technology for SIM interferometer real time control is successfully operating on several SIM technology demonstration testbeds, including the Real-time Interferometer Control System Testbed, System Testbed-3, and the Microarcsecond Metrology testbed. This paper provides an overview of the architecture, design, integration, and test of the SIM flight interferometer real time control to meet challenging flight system requirements for the high processor throughput, low-latency interconnect, and precise synchronization to support microarcsecond-level astrometric measurements for greater than five years at 1 AU in Earth-trailing orbit. The electronics and software architecture of the interferometer real time control core and its adaptation to a flight design concept are described. Control loops for pointing and pathlength control within each of four flight interferometers and for coordination of control and data across interferometers are illustrated. The nature of onboard data processing to fit average downlink rates while retaining post-processed astrometric measurement precision and accuracy is also addressed. Interferometer flight software will be developed using a software simulation environment incorporating models of the metrology and starlight sensors and actuators to close the real time control loops. RTC flight software and instrument flight electronics will in turn be integrated utilizing the same simulation architecture for metrology and starlight component models to close real time control loops and verify RTC functionality and performance prior to delivery to flight interferometer system integration at Lockheed Martin

  15. Real-time interferometric synthetic aperture microscopy.

    PubMed

    Ralston, Tyler S; Marks, Daniel L; Carney, P Scott; Boppart, Stephen A

    2008-02-18

    An interferometric synthetic aperture microscopy (ISAM) system design with real-time 2D cross-sectional processing is described in detail. The system can acquire, process, and display the ISAM reconstructed images at frame rates of 2.25 frames per second for 512 X 1024 pixel images. This system provides quantitatively meaningful structural information from previously indistinguishable scattering intensities and provides proof of feasibility for future real-time ISAM systems. PMID:18542337

  16. Processing PCM Data in Real Time

    NASA Technical Reports Server (NTRS)

    Wissink, T. L.

    1982-01-01

    Novel hardware configuration makes it possible for Space Shuttle launch processing system to monitor pulse-code-modulated data in real time. Using two microprogramable "option planes," incoming PCM data are monitored for changes at rate of one frame of data (80 16-bit words) every 10 milliseconds. Real-time PCM processor utilizes CPU in mini-computer and CPU's in two option planes.

  17. Real-time scheduling using minimum search

    NASA Technical Reports Server (NTRS)

    Tadepalli, Prasad; Joshi, Varad

    1992-01-01

    In this paper we consider a simple model of real-time scheduling. We present a real-time scheduling system called RTS which is based on Korf's Minimin algorithm. Experimental results show that the schedule quality initially improves with the amount of look-ahead search and tapers off quickly. So it sppears that reasonably good schedules can be produced with a relatively shallow search.

  18. The LAA real-time benchmarks

    SciTech Connect

    Block, R.K.; Krischer, W.; Lone, S.

    1989-04-01

    In the context of the LAA detector development program a subgroup Real Time Data Processing has tackled the problem of intelligent triggering. The main goal of this group is to show how fast digital devices, implemented as custom-made or commercial processors, can execute some basic algorithms, and how they can be embedded in the data flow between detector readout components and fully programmable commercial processors, which are expected to be the final data processing filter in real time.

  19. Real-time GPS monitoring throughout Cascadia

    NASA Astrophysics Data System (ADS)

    Melbourne, T. I.; Santillan, V. M.; Scrivner, C. W.; Szeliga, W. M.; Webb, F.; Abundiz, S.

    2012-12-01

    Over 400 GPS receivers of the combined PANGA and PBO networks currently operate along the Cascadia subduction zone, all of which are high-rate and telemetered in real-time. These receivers span the M9 megathrust, M7 crustal faults beneath population centers, several active Cascades volcanoes, and a host of other hazard sources, and together enable a host of new approaches towards hazards mitigation. Data from the majority of the stations is received in real time at CWU and processed into one-second position estimates using 1) relative positioning within several reference frames constrained by 2) absolute point positioning using streamed satellite orbit and clock corrections. While the former produces lower-noise time series, for earthquakes greater than ~M7 and ground displacements exceeding ~20 cm, point positioning alone is shown to provide very rapid and robust estimates of the location and amplitude of both dynamic strong ground motion and permanent deformation. Raw phase and range observables from stations throughout Cascadia are being processed in real time at JPL and CWU into station positions, which in turn are analyzed also in real-time for earthquake processes at CWU. Our efforts can be broken down into three distinct areas: 1) Real-time point-positioning methodologies, 2) a data aggregator that captures real-time position streams from a variety of processing centers and methodologies (JPL RTGipsy, CWU rtPP, Trimble VRS) and re-streams the data as configurable streams to application clients out anywhere on the web, and 3) a suite of analysis tools that operate on the real-time position streams, including plotting, vectors, peak ground deformation contouring, and finite-fault inversions. This suite is currently bundled within a single client written in JAVA, called 'GPS Cockpit.'

  20. Characterization of real-time computers

    NASA Technical Reports Server (NTRS)

    Shin, K. G.; Krishna, C. M.

    1984-01-01

    A real-time system consists of a computer controller and controlled processes. Despite the synergistic relationship between these two components, they have been traditionally designed and analyzed independently of and separately from each other; namely, computer controllers by computer scientists/engineers and controlled processes by control scientists. As a remedy for this problem, in this report real-time computers are characterized by performance measures based on computer controller response time that are: (1) congruent to the real-time applications, (2) able to offer an objective comparison of rival computer systems, and (3) experimentally measurable/determinable. These measures, unlike others, provide the real-time computer controller with a natural link to controlled processes. In order to demonstrate their utility and power, these measures are first determined for example controlled processes on the basis of control performance functionals. They are then used for two important real-time multiprocessor design applications - the number-power tradeoff and fault-masking and synchronization.

  1. Real-Time Wireless Data Acquisition System

    NASA Technical Reports Server (NTRS)

    Valencia, Emilio J.; Perotti, Jose; Lucena, Angel; Mata, Carlos

    2007-01-01

    Current and future aerospace requirements demand the creation of a new breed of sensing devices, with emphasis on reduced weight, power consumption, and physical size. This new generation of sensors must possess a high degree of intelligence to provide critical data efficiently and in real-time. Intelligence will include self-calibration, self-health assessment, and pre-processing of raw data at the sensor level. Most of these features are already incorporated in the Wireless Sensors Network (SensorNet(TradeMark)), developed by the Instrumentation Group at Kennedy Space Center (KSC). A system based on the SensorNet(TradeMark) architecture consists of data collection point(s) called Central Stations (CS) and intelligent sensors called Remote Stations (RS) where one or more CSs can be accommodated depending on the specific application. The CS's major function is to establish communications with the Remote Stations and to poll each RS for data and health information. The CS also collects, stores and distributes these data to the appropriate systems requiring the information. The system has the ability to perform point-to-point, multi-point and relay mode communications with an autonomous self-diagnosis of each communications link. Upon detection of a communication failure, the system automatically reconfigures to establish new communication paths. These communication paths are automatically and autonomously selected as the best paths by the system based on the existing operating environment. The data acquisition system currently under development at KSC consists of the SensorNet(TradeMark) wireless sensors as the remote stations and the central station called the Radio Frequency Health Node (RFHN). The RFF1N is the central station which remotely communicates with the SensorNet(TradeMark) sensors to control them and to receive data. The system's salient feature is the ability to provide deterministic sensor data with accurate time stamps for both time critical and non-time

  2. INTA-SAR real-time processor

    SciTech Connect

    Gomez, B.; Leon, J.

    1996-10-01

    This paper presents the INTASAR real time processor development based on a DSP open architecture for processing Synthetic Aperture Radar (SAR) signal. The final designed architecture must consider three different constraints sources: (a) SAR signal characteristics : high dynamic range, and complex SAR imaging algorithms with high computational load (multiprocessing is convenient). (b) Flexible: in connectivity and algorithms to be programmed. (c) Suitable: for on-board and ground working. The real time constraints will be defined by the image acquisition time, within it the INTASAR system will process the rawdata image and finally presents the results in the system monitor. At ground, however, the real time processing is not a constraint, but the high quality image is. The first algorithm implemented in the system was a Range - Doppler one. With the multiprocessor architecture selected, a pipeline processing method is used. 17 refs., 4 figs., 2 tabs.

  3. Real-Time Gauge/Gravity Duality

    SciTech Connect

    Skenderis, Kostas; Rees, Balt C. van

    2008-08-22

    We present a general prescription for the holographic computation of real-time n-point functions in nontrivial states. In quantum field theory such real-time computations involve a choice of a time contour in the complex time plane. The holographic prescription amounts to 'filling in' this contour with bulk solutions: real segments of the contour are filled in with Lorentzian solutions while imaginary segments are filled in with Riemannian solutions and appropriate matching conditions are imposed at the corners of the contour. We illustrate the general discussion by computing the 2-point function of a scalar operator using this prescription and by showing that this leads to an unambiguous answer with the correct i{epsilon} insertions.

  4. Quantitative Real-Time PCR: Recent Advances.

    PubMed

    Singh, Charanjeet; Roy-Chowdhuri, Sinchita

    2016-01-01

    Quantitative real-time polymerase chain reaction is a technique for simultaneous amplification and product quantification of a target DNA as the process takes place in real time in a "closed-tube" system. Although this technique can provide an absolute quantification of the initial template copy number, quantification relative to a control sample or second sequence is typically adequate. The quantification process employs melting curve analysis and/or fluorescent detection systems and can provide amplification and genotyping in a relatively short time. Here we describe the properties and uses of various fluorescent detection systems used for quantification. PMID:26843055

  5. Real-time Enhanced Vision System

    NASA Technical Reports Server (NTRS)

    Hines, Glenn D.; Rahman, Zia-Ur; Jobson, Daniel J.; Woodell, Glenn A.; Harrah, Steven D.

    2005-01-01

    Flying in poor visibility conditions, such as rain, snow, fog or haze, is inherently dangerous. However these conditions can occur at nearly any location, so inevitably pilots must successfully navigate through them. At NASA Langley Research Center (LaRC), under support of the Aviation Safety and Security Program Office and the Systems Engineering Directorate, we are developing an Enhanced Vision System (EVS) that combines image enhancement and synthetic vision elements to assist pilots flying through adverse weather conditions. This system uses a combination of forward-looking infrared and visible sensors for data acquisition. A core function of the system is to enhance and fuse the sensor data in order to increase the information content and quality of the captured imagery. These operations must be performed in real-time for the pilot to use while flying. For image enhancement, we are using the LaRC patented Retinex algorithm since it performs exceptionally well for improving low-contrast range imagery typically seen during poor visibility conditions. In general, real-time operation of the Retinex requires specialized hardware. To date, we have successfully implemented a single-sensor real-time version of the Retinex on several different Digital Signal Processor (DSP) platforms. In this paper we give an overview of the EVS and its performance requirements for real-time enhancement and fusion and we discuss our current real-time Retinex implementations on DSPs.

  6. Real-time enhanced vision system

    NASA Astrophysics Data System (ADS)

    Hines, Glenn D.; Rahman, Zia-ur; Jobson, Daniel J.; Woodell, Glenn A.; Harrah, Steven D.

    2005-05-01

    Flying in poor visibility conditions, such as rain, snow, fog or haze, is inherently dangerous. However these conditions can occur at nearly any location, so inevitably pilots must successfully navigate through them. At NASA Langley Research Center (LaRC), under support of the Aviation Safety and Security Program Office and the Systems Engineering Directorate, we are developing an Enhanced Vision System (EVS) that combines image enhancement and synthetic vision elements to assist pilots flying through adverse weather conditions. This system uses a combination of forward-looking infrared and visible sensors for data acquisition. A core function of the system is to enhance and fuse the sensor data in order to increase the information content and quality of the captured imagery. These operations must be performed in real-time for the pilot to use while flying. For image enhancement, we are using the LaRC patented Retinex algorithm since it performs exceptionally well for improving low-contrast range imagery typically seen during poor visibility poor visibility conditions. In general, real-time operation of the Retinex requires specialized hardware. To date, we have successfully implemented a single-sensor real-time version of the Retinex on several different Digital Signal Processor (DSP) platforms. In this paper we give an overview of the EVS and its performance requirements for real-time enhancement and fusion and we discuss our current real-time Retinex implementations on DSPs.

  7. Hard Real-Time: C++ Versus RTSJ

    NASA Technical Reports Server (NTRS)

    Dvorak, Daniel L.; Reinholtz, William K.

    2004-01-01

    In the domain of hard real-time systems, which language is better: C++ or the Real-Time Specification for Java (RTSJ)? Although ordinary Java provides a more productive programming environment than C++ due to its automatic memory management, that benefit does not apply to RTSJ when using NoHeapRealtimeThread and non-heap memory areas. As a result, RTSJ programmers must manage non-heap memory explicitly. While that's not a deterrent for veteran real-time programmers-where explicit memory management is common-the lack of certain language features in RTSJ (and Java) makes that manual memory management harder to accomplish safely than in C++. This paper illustrates the problem for practitioners in the context of moving data and managing memory in a real-time producer/consumer pattern. The relative ease of implementation and safety of the C++ programming model suggests that RTSJ has a struggle ahead in the domain of hard real-time applications, despite its other attractive features.

  8. Feedback as Real-Time Constructions

    ERIC Educational Resources Information Center

    Keiding, Tina Bering; Qvortrup, Ane

    2014-01-01

    This article offers a re-description of feedback and the significance of time in feedback constructions based on systems theory. It describes feedback as internal, real-time constructions in a learning system. From this perspective, feedback is neither immediate nor delayed, but occurs in the very moment it takes place. This article argues for a…

  9. Real-Time Visualization of Tissue Ischemia

    NASA Technical Reports Server (NTRS)

    Bearman, Gregory H. (Inventor); Chrien, Thomas D. (Inventor); Eastwood, Michael L. (Inventor)

    2000-01-01

    A real-time display of tissue ischemia which comprises three CCD video cameras, each with a narrow bandwidth filter at the correct wavelength is discussed. The cameras simultaneously view an area of tissue suspected of having ischemic areas through beamsplitters. The output from each camera is adjusted to give the correct signal intensity for combining with, the others into an image for display. If necessary a digital signal processor (DSP) can implement algorithms for image enhancement prior to display. Current DSP engines are fast enough to give real-time display. Measurement at three, wavelengths, combined into a real-time Red-Green-Blue (RGB) video display with a digital signal processing (DSP) board to implement image algorithms, provides direct visualization of ischemic areas.

  10. Durham adaptive optics real-time controller.

    PubMed

    Basden, Alastair; Geng, Deli; Myers, Richard; Younger, Eddy

    2010-11-10

    The Durham adaptive optics (AO) real-time controller was initially a proof of concept design for a generic AO control system. It has since been developed into a modern and powerful central-processing-unit-based real-time control system, capable of using hardware acceleration (including field programmable gate arrays and graphical processing units), based primarily around commercial off-the-shelf hardware. It is powerful enough to be used as the real-time controller for all currently planned 8 m class telescope AO systems. Here we give details of this controller and the concepts behind it, and report on performance, including latency and jitter, which is less than 10 μs for small AO systems. PMID:21068868

  11. Continuous, real time microwave plasma element sensor

    DOEpatents

    Woskov, P.P.; Smatlak, D.L.; Cohn, D.R.; Wittle, J.K.; Titus, C.H.; Surma, J.E.

    1995-12-26

    Microwave-induced plasma is described for continuous, real time trace element monitoring under harsh and variable conditions. The sensor includes a source of high power microwave energy and a shorted waveguide made of a microwave conductive, refractory material communicating with the source of the microwave energy to generate a plasma. The high power waveguide is constructed to be robust in a hot, hostile environment. It includes an aperture for the passage of gases to be analyzed and a spectrometer is connected to receive light from the plasma. Provision is made for real time in situ calibration. The spectrometer disperses the light, which is then analyzed by a computer. The sensor is capable of making continuous, real time quantitative measurements of desired elements, such as the heavy metals lead and mercury. 3 figs.

  12. Continuous, real time microwave plasma element sensor

    DOEpatents

    Woskov, Paul P.; Smatlak, Donna L.; Cohn, Daniel R.; Wittle, J. Kenneth; Titus, Charles H.; Surma, Jeffrey E.

    1995-01-01

    Microwave-induced plasma for continuous, real time trace element monitoring under harsh and variable conditions. The sensor includes a source of high power microwave energy and a shorted waveguide made of a microwave conductive, refractory material communicating with the source of the microwave energy to generate a plasma. The high power waveguide is constructed to be robust in a hot, hostile environment. It includes an aperture for the passage of gases to be analyzed and a spectrometer is connected to receive light from the plasma. Provision is made for real time in situ calibration. The spectrometer disperses the light, which is then analyzed by a computer. The sensor is capable of making continuous, real time quantitative measurements of desired elements, such as the heavy metals lead and mercury.

  13. Real-Time Sensor Validation System Developed

    NASA Technical Reports Server (NTRS)

    Zakrajsek, June F.

    1998-01-01

    Real-time sensor validation improves process monitoring and control system dependability by ensuring data integrity through automated detection of sensor data failures. The NASA Lewis Research Center, Expert Microsystems, and Intelligent Software Associates have developed an innovative sensor validation system that can automatically detect automated sensor failures in real-time for all types of mission-critical systems. This system consists of a sensor validation network development system and a real-time kernel. The network development system provides tools that enable systems engineers to automatically generate software that can be embedded within an application. The sensor validation methodology captured by these tools can be scaled to validate any number of sensors, and permits users to specify system sensitivity. The resulting software reliably detects all types of sensor data failures.

  14. Real-time cardiac MRI using DSP's.

    PubMed

    Morgan, P N; Iannuzzelli, R J; Epstein, F H; Balaban, R S

    1999-07-01

    A real-time cardiac magnetic resonance imaging (MRI) system has been implemented using digital signal processing (DSP) technology. The system enables real-time acquisition, processing, and display of ungated cardiac movies at moderate video rates of 20 images/s. A custom graphical user interface (GUI) provides interactive control of data acquisition parameters and image display functions. Images can be compressed into moving-picture experts group (MPEG) movies, but are displayed on the console without compression during the scan. Compared to existing real-time MRI systems, implementation with DSP's allows rapid parallel computations, fast data transfers, and greater system flexibility, including the ability to scale to multiple channels, at the expense of somewhat higher component cost. PMID:10504098

  15. Network protocols for real-time applications

    NASA Technical Reports Server (NTRS)

    Johnson, Marjory J.

    1987-01-01

    The Fiber Distributed Data Interface (FDDI) and the SAE AE-9B High Speed Ring Bus (HSRB) are emerging standards for high-performance token ring local area networks. FDDI was designed to be a general-purpose high-performance network. HSRB was designed specifically for military real-time applications. A workshop was conducted at NASA Ames Research Center in January, 1987 to compare and contrast these protocols with respect to their ability to support real-time applications. This report summarizes workshop presentations and includes an independent comparison of the two protocols. A conclusion reached at the workshop was that current protocols for the upper layers of the Open Systems Interconnection (OSI) network model are inadequate for real-time applications.

  16. Real-time hyperspectral detection and cuing

    NASA Astrophysics Data System (ADS)

    Stellman, Christopher M.; Hazel, Geoff; Bucholtz, Frank; Michalowicz, Joseph V.; Stocker, Alan D.; Schaaf, William

    2000-07-01

    The Dark HORSE 1 (Hyperspectral Overhead Reconnaissance and Surveillance Experiment 1) flight test has demonstrated autonomous, real-time visible hyperspectral detection of military ground targets with real-time cuing of a high- resolution framing camera. An overview of the Dark HORSE 1 hyperspectral sensor system is presented. The system hardware components are described in detail, with an emphasis on the visible hyperspectral sensor and the real- time processor. Descriptions of system software and processing methods are also provided. The recent field experiment in which the Dark HORSE 1 system was employed is described in detail along with an analysis of the collected data. The results evince per-pixel false-alarm rates on the order of 10-5/km2, and demonstrate the improved performance obtained by operating two detection algorithms simultaneously.

  17. Spectral decontamination of a real-time helicopter simulation

    NASA Technical Reports Server (NTRS)

    Mcfarland, R. E.

    1983-01-01

    Nonlinear mathematical models of a rotor system, referred to as rotating blade-element models, produce steady-state, high-frequency harmonics of significant magnitude. In a discrete simulation model, certain of these harmonics may be incompatible with realistic real-time computational constraints because of their aliasing into the operational low-pass region. However, the energy is an aliased harmonic may be suppressed by increasing the computation rate of an isolated, causal nonlinearity and using an appropriate filter. This decontamination technique is applied to Sikorsky's real-time model of the Black Hawk helicopter, as supplied to NASA for handling-qualities investigations.

  18. Real-time pseudocolor coding thermal ghost imaging.

    PubMed

    Duan, Deyang; Xia, Yunjie

    2014-01-01

    In this work, a color ghost image of a black-and-white object is obtained by a real-time pseudocolor coding technique that includes equal spatial frequency pseudocolor coding and equal density pseudocolor coding. This method makes the black-and-white ghost image more conducive to observation. Furthermore, since the ghost imaging comes from the intensity cross-correlations of the two beams, ghost imaging with the real-time pseudocolor coding technique is better than classical optical imaging with the same technique in overcoming the effects of light interference. PMID:24561954

  19. Real-time linear predictive analysis of speech using multimicroprocessors

    SciTech Connect

    Seethardman, S.; Radhakrishnan, T.; Suen, C.Y.

    1982-01-01

    Many applications of linear predictive coding (often known as LPC) of speech signals require a system capable of performing the complete LPC analysis in real time. This paper describes a pipeline network consisting of several general purpose microprocessors, primarily suitable for complete LPC analysis of a 10-pole model with a sampling frequency of 10 khz and a frame rate of 100 hz in real time. The proposed system is different from the previous systems, which either employed special purpose hardware or produced an analysis at a lower frame rate. 27 references.

  20. Real Time Linux - The RTOS for Astronomy?

    NASA Astrophysics Data System (ADS)

    Daly, P. N.

    The BoF was attended by about 30 participants and a free CD of real time Linux-based upon RedHat 5.2-was available. There was a detailed presentation on the nature of real time Linux and the variants for hard real time: New Mexico Tech's RTL and DIAPM's RTAI. Comparison tables between standard Linux and real time Linux responses to time interval generation and interrupt response latency were presented (see elsewhere in these proceedings). The present recommendations are to use RTL for UP machines running the 2.0.x kernels and RTAI for SMP machines running the 2.2.x kernel. Support, both academically and commercially, is available. Some known limitations were presented and the solutions reported e.g., debugging and hardware support. The features of RTAI (scheduler, fifos, shared memory, semaphores, message queues and RPCs) were described. Typical performance statistics were presented: Pentium-based oneshot tasks running > 30kHz, 486-based oneshot tasks running at ~ 10 kHz, periodic timer tasks running in excess of 90 kHz with average zero jitter peaking to ~ 13 mus (UP) and ~ 30 mus (SMP). Some detail on kernel module programming, including coding examples, were presented showing a typical data acquisition system generating simulated (random) data writing to a shared memory buffer and a fifo buffer to communicate between real time Linux and user space. All coding examples were complete and tested under RTAI v0.6 and the 2.2.12 kernel. Finally, arguments were raised in support of real time Linux: it's open source, free under GPL, enables rapid prototyping, has good support and the ability to have a fully functioning workstation capable of co-existing hard real time performance. The counter weight-the negatives-of lack of platforms (x86 and PowerPC only at present), lack of board support, promiscuous root access and the danger of ignorance of real time programming issues were also discussed. See ftp://orion.tuc.noao.edu/pub/pnd/rtlbof.tgz for the StarOffice overheads

  1. Making Real-Time Data "Real" for General Interest Users

    NASA Astrophysics Data System (ADS)

    Hotaling, L.

    2003-04-01

    Helping educators realize the benefits of integrating technology into curricula to effectively engage student learning and improve student achievement, particularly in science and mathematics, is the core mission of the Center for Improved Engineering and Science Education (CIESE). To achieve our mission, we focus on projects utilizing real-time data available from the Internet, and collaborative projects utilizing the Internet's potential to reach peers and experts around the world. As a member of the Mid-Atlantic Center for Ocean Sciences Education Excellence (COSEE), the Center for Improved Engineering and Science Education (CIESE), is committed to delivering relevant ocean science education to diverse audiences, including K-12 teachers, students, coastal managers, families and tourists. The highest priority of the Mid-Atlantic COSEE is to involve scientists and educators in the translation of data and information from the coastal observatories into instructional materials and products usable by educators and the public. A combination of three regional observing systems, the New Jersey Shelf Observing System (NJSOS), Chesapeake Bay Observing System (CBOS), and the York River observing system will provide the scientific backbone for an integrated program of science and education that improves user access to, and understanding of, modern ocean science and how it affects our daily lives. At present, the Mid-Atlantic COSEE offers three projects that enable users to apply and validate scientific concepts to real world situations. (1) The Gulf Stream Voyage is an online multidisciplinary project that utilizes both real-time data and primary source materials to help guide students to discover the science and history of the Gulf Stream current. (2) C.O.O.L. Classroom is an online project that utilizes concepts and real-time data collected through the NJSOS. The C.O.O.L. Classroom is based on the concept of the Rutgers-IMCS Coastal Ocean Observation Laboratory, a real

  2. Real-Time Parameter Estimation Using Output Error

    NASA Technical Reports Server (NTRS)

    Grauer, Jared A.

    2014-01-01

    Output-error parameter estimation, normally a post- ight batch technique, was applied to real-time dynamic modeling problems. Variations on the traditional algorithm were investigated with the goal of making the method suitable for operation in real time. Im- plementation recommendations are given that are dependent on the modeling problem of interest. Application to ight test data showed that accurate parameter estimates and un- certainties for the short-period dynamics model were available every 2 s using time domain data, or every 3 s using frequency domain data. The data compatibility problem was also solved in real time, providing corrected sensor measurements every 4 s. If uncertainty corrections for colored residuals are omitted, this rate can be increased to every 0.5 s.

  3. Machine vision for real time orbital operations

    NASA Technical Reports Server (NTRS)

    Vinz, Frank L.

    1988-01-01

    Machine vision for automation and robotic operation of Space Station era systems has the potential for increasing the efficiency of orbital servicing, repair, assembly and docking tasks. A machine vision research project is described in which a TV camera is used for inputing visual data to a computer so that image processing may be achieved for real time control of these orbital operations. A technique has resulted from this research which reduces computer memory requirements and greatly increases typical computational speed such that it has the potential for development into a real time orbital machine vision system. This technique is called AI BOSS (Analysis of Images by Box Scan and Syntax).

  4. Automated real-time software development

    NASA Technical Reports Server (NTRS)

    Jones, Denise R.; Walker, Carrie K.; Turkovich, John J.

    1993-01-01

    A Computer-Aided Software Engineering (CASE) system has been developed at the Charles Stark Draper Laboratory (CSDL) under the direction of the NASA Langley Research Center. The CSDL CASE tool provides an automated method of generating source code and hard copy documentation from functional application engineering specifications. The goal is to significantly reduce the cost of developing and maintaining real-time scientific and engineering software while increasing system reliability. This paper describes CSDL CASE and discusses demonstrations that used the tool to automatically generate real-time application code.

  5. Axial Tomography from Digitized Real Time Radiography

    DOE R&D Accomplishments Database

    Zolnay, A. S.; McDonald, W. M.; Doupont, P. A.; McKinney, R. L.; Lee, M. M.

    1985-01-18

    Axial tomography from digitized real time radiographs provides a useful tool for industrial radiography and tomography. The components of this system are: x-ray source, image intensifier, video camera, video line extractor and digitizer, data storage and reconstruction computers. With this system it is possible to view a two dimensional x-ray image in real time at each angle of rotation and select the tomography plane of interest by choosing which video line to digitize. The digitization of a video line requires less than a second making data acquisition relatively short. Further improvements on this system are planned and initial results are reported.

  6. Software Package For Real-Time Graphics

    NASA Technical Reports Server (NTRS)

    Malone, Jacqueline C.; Moore, Archie L.

    1991-01-01

    Software package for master graphics interactive console (MAGIC) at Western Aeronautical Test Range (WATR) of NASA Ames Research Center provides general-purpose graphical display system for real-time and post-real-time analysis of data. Written in C language and intended for use on workstation of interactive raster imaging system (IRIS) equipped with level-V Unix operating system. Enables flight researchers to create their own displays on basis of individual requirements. Applicable to monitoring of complicated processes in chemical industry.

  7. Real-Time, Interactive Sonic Boom Display

    NASA Technical Reports Server (NTRS)

    Haering, Jr., Edward A. (Inventor); Plotkin, Kenneth J. (Inventor)

    2012-01-01

    The present invention is an improved real-time, interactive sonic boom display for aircraft. By using physical properties obtained via various sensors and databases, the invention determines, in real-time, sonic boom impacts locations and intensities for aircraft traveling at supersonic speeds. The information is provided to a pilot via a display that lists a selectable set of maneuvers available to the pilot to mitigate sonic boom issues. Upon selection of a maneuver, the information as to the result of the maneuver is displayed and the pilot may proceed with making the maneuver, or provide new data to the system in order to calculate a different maneuver.

  8. Real-Time Occupancy Change Analyzer

    Energy Science and Technology Software Center (ESTSC)

    2005-03-30

    The Real-Time Occupancy Change Analyzer (ROCA) produces an occupancy grid map of an environment around the robot, scans the environment to generate a current obstacle map relative to a current robot position, and converts the current obstacle map to a current occupancy grid map. Changes in the occupancy grid can be reported in real time to support a number of tracking capabilities. The benefit of ROCA is that rather than only providing a vector tomore » the detected change, it provides the actual x,y position of the change.« less

  9. OPAD-EDIFIS Real-Time Processing

    NASA Technical Reports Server (NTRS)

    Katsinis, Constantine

    1997-01-01

    The Optical Plume Anomaly Detection (OPAD) detects engine hardware degradation of flight vehicles through identification and quantification of elemental species found in the plume by analyzing the plume emission spectra in a real-time mode. Real-time performance of OPAD relies on extensive software which must report metal amounts in the plume faster than once every 0.5 sec. OPAD software previously written by NASA scientists performed most necessary functions at speeds which were far below what is needed for real-time operation. The research presented in this report improved the execution speed of the software by optimizing the code without changing the algorithms and converting it into a parallelized form which is executed in a shared-memory multiprocessor system. The resulting code was subjected to extensive timing analysis. The report also provides suggestions for further performance improvement by (1) identifying areas of algorithm optimization, (2) recommending commercially available multiprocessor architectures and operating systems to support real-time execution and (3) presenting an initial study of fault-tolerance requirements.

  10. Real-Time Fourier Synthesis of Ensembles with Timbral Interpolation

    NASA Astrophysics Data System (ADS)

    Haken, Lippold

    1990-01-01

    In Fourier synthesis, natural musical sounds are produced by summing time-varying sinusoids. Sounds are analyzed to find the amplitude and frequency characteristics for their sinusoids; interpolation between the characteristics of several sounds is used to produce intermediate timbres. An ensemble can be synthesized by summing all the sinusoids for several sounds, but in practice it is difficult to perform such computations in real time. To solve this problem on inexpensive hardware, it is useful to take advantage of the masking effects of the auditory system. By avoiding the computations for perceptually unimportant sinusoids, and by employing other computation reduction techniques, a large ensemble may be synthesized in real time on the Platypus signal processor. Unlike existing computation reduction techniques, the techniques described in this thesis do not sacrifice independent fine control over the amplitude and frequency characteristics of each sinusoid.

  11. Analysis of Three Real-Time Dst Indices

    NASA Astrophysics Data System (ADS)

    Carranza-Fulmer, T. L.; Gannon, J. L.; Love, J. J.

    2010-12-01

    The Dst is commonly used to specify geomagnetic disturbance periods and characterize the resulting ring current enhancements from ground-based horizontal magnetic field intensity measurements. Real-time versions of the Dst index are produced for operational purposes, and are of interest to many users, including the US military, airline industry, and power companies. USGS Real time Dst, Kyoto Quicklook Dst, and Space Environment Corporation RDst use preliminary data and use a variety of contributing observatories and processing methods. Both USGS and RDst use a combined time-and-frequency domain method and Kyoto uses a time domain only method in creating the Dst index. We perform an analysis of these three real time Dst indices for the time period of October 1, 2009 to May 31, 2010. The USGS 3, using three observatories instead of the standard four, and the Kyoto Sym-H index, are introduced in the analysis for comparison of observatory location with the three main Dst indices. We present a statistical study of the differences due to algorithm, output time resolution, and location of contributing observatories. Higher time resolution shows higher frequency fluctuations during disturbances and more defined storm features. There were small differences in mid- to low-latitude observatories during quiet to moderate storm time periods. The average impact on the index due to the different algorithms used was approximately 9 nT, and greater for individual storms.

  12. The Real Time Display Builder (RTDB)

    NASA Technical Reports Server (NTRS)

    Kindred, Erick D.; Bailey, Samuel A., Jr.

    1989-01-01

    The Real Time Display Builder (RTDB) is a prototype interactive graphics tool that builds logic-driven displays. These displays reflect current system status, implement fault detection algorithms in real time, and incorporate the operational knowledge of experienced flight controllers. RTDB utilizes an object-oriented approach that integrates the display symbols with the underlying operational logic. This approach allows the user to specify the screen layout and the driving logic as the display is being built. RTDB is being developed under UNIX in C utilizing the MASSCOMP graphics environment with appropriate functional separation to ease portability to other graphics environments. RTDB grew from the need to develop customized real-time data-driven Space Shuttle systems displays. One display, using initial functionality of the tool, was operational during the orbit phase of STS-26 Discovery. RTDB is being used to produce subsequent displays for the Real Time Data System project currently under development within the Mission Operations Directorate at NASA/JSC. The features of the tool, its current state of development, and its applications are discussed.

  13. Real Time Grid Reliability Management 2005

    SciTech Connect

    Eto, Joe; Eto, Joe; Lesieutre, Bernard; Lewis, Nancy Jo; Parashar, Manu

    2008-07-07

    The increased need to manage California?s electricity grid in real time is a result of the ongoing transition from a system operated by vertically-integrated utilities serving native loads to one operated by an independent system operator supporting competitive energy markets. During this transition period, the traditional approach to reliability management -- construction of new transmission lines -- has not been pursued due to unresolved issues related to the financing and recovery of transmission project costs. In the absence of investments in new transmission infrastructure, the best strategy for managing reliability is to equip system operators with better real-time information about actual operating margins so that they can better understand and manage the risk of operating closer to the edge. A companion strategy is to address known deficiencies in offline modeling tools that are needed to ground the use of improved real-time tools. This project: (1) developed and conducted first-ever demonstrations of two prototype real-time software tools for voltage security assessment and phasor monitoring; and (2) prepared a scoping study on improving load and generator response models. Additional funding through two separate subsequent work authorizations has already been provided to build upon the work initiated in this project.

  14. Real-Time Operating System/360

    NASA Technical Reports Server (NTRS)

    Hoffman, R. L.; Kopp, R. S.; Mueller, H. H.; Pollan, W. D.; Van Sant, B. W.; Weiler, P. W.

    1969-01-01

    RTOS has a cost savings advantage for real-time applications, such as those with random inputs requiring a flexible data routing facility, display systems simplified by a device independent interface language, and complex applications needing added storage protection and data queuing.

  15. The Power of Real-Time PCR

    ERIC Educational Resources Information Center

    Valasek, Mark A.; Repa, Joyce J.

    2005-01-01

    In recent years, real-time polymerase chain reaction (PCR) has emerged as a robust and widely used methodology for biological investigation because it can detect and quantify very small amounts of specific nucleic acid sequences. As a research tool, a major application of this technology is the rapid and accurate assessment of changes in gene…

  16. Real-Time Multidetector Neutron Spectrometer

    NASA Astrophysics Data System (ADS)

    Drejzin, V. E.; Grimov, A. A.; Logvinov, D. I.

    2016-07-01

    We explain a new approach to constructing a real-time neutron spectrometer, using several detectors with different spectral characteristics and coprocessing the data using a pre-trained neural network. We present the results of simulation and experimental studies on a prototype, demonstrating the effectiveness of this approach.

  17. Real-time distributed multimedia systems

    SciTech Connect

    Rahurkar, S.S.; Bourbakis, N.G.

    1996-12-31

    This paper presents a survey on distributed multimedia systems and discusses real-time issues. In particular, different subsystems are reviewed that impact on multimedia networking, the networking for multimedia, the networked multimedia systems, and the leading edge research and developments efforts and issues in networking.

  18. Real time solar magnetograph Skylab mission Atlas

    NASA Technical Reports Server (NTRS)

    Hagyard, M. J.; Cumings, N. P.

    1975-01-01

    An atlas of all magnetic field observations made during the Skylab missions with the Real Time Solar Magnetograph system located at the Marshall Space Flight Center is presented. Also included are a description of the system and its operation; an outline of the data reductions performed; and a discussion of probable errors, noise, magnetic sensitivity, and system reliability.

  19. Real-Time Blackboards For Sensor Fusions

    NASA Astrophysics Data System (ADS)

    Johnson, Donald H.; Shaw, Scott W.; Reynolds, Steven; Himayat, Nageen

    1989-09-01

    Multi-sensor fusion, at the most basic level, can be cast into a concise, elegant model. Reality demands, however, that this model be modified and augmented. These modifications often result in software systems that are confusing in function and difficult to debug. This problem can be ameliorated by adopting an object-oriented, data-flow programming style. For real-time applications, this approach simplifies data communications and storage management. The concept of object-oriented, data-flow programming is conveniently embodied in the black-board style of software architecture. Blackboard systems allow diverse programs access to a central data base. When the blackboard is described as an object, it can be distributed over multiple processors for real-time applications. Choosing the appropriate parallel architecture is the subject of ongoing research. A prototype blackboard has been constructed to fuse optical image regions and Doppler radar events. The system maintains tracks of simulated targets in real time. The results of this simulation have been used to direct further research on real-time blackboard systems.

  20. Real-time optoacoustic monitoring during thermotherapy

    NASA Astrophysics Data System (ADS)

    Esenaliev, Rinat O.; Larina, Irina V.; Larin, Kirill V.; Motamedi, Massoud

    2000-05-01

    Optoacoustic monitoring of tissue optical properties and speed of sound in real time can provide fast and accurate feedback information during thermotherapy performed with various heating or cooling agents. Amplitude and temporal characteristics of optoacoustic pressure waves are dependent on tissue properties. Detection and measurement of the optoacoustic waves may be used to monitor the extent of tissue hyperthermia, coagulation, or freezing with high resolution and contrast. We studied real-time optoacoustic monitoring of thermal coagulation induced by conductive heating and laser radiation and cryoablation with liquid nitrogen. Q-switched Nd:YAG laser pulses were used as probing radiation to induce optoacoustic waves in tissues. Dramatic changes in optoacoustic signal parameters were detected during tissue freezing and coagulation due to sharp changes in tissue properties. The dimensions of thermally- induced lesions were measured in real time with the optoacoustic technique. Our studies demonstrated that the laser optoacoustic technique is capable of real-time monitoring of tissue coagulation and freezing front with submillimeter spatial resolution. This may allow accurate thermal ablation or cryotherapy of malignant and benign lesions with minimal damage to normal tissues.

  1. Solar neutrinos: Real-time experiments

    NASA Astrophysics Data System (ADS)

    Totsuka, Yoji

    1993-04-01

    This report outlines the principle of real-time solar neutrino detection experiments by detecting electrons with suitable target material, via Charged-Current (CC) reaction using conventional counting techniques developed in high-energy physics. Only B-8 neutrinos can be detected by minimum detectable energy of several MeV. The MSW (Mikheyev, Smirnov, Wolfenstein) effect not only distorts the energy spectrum but also induces new type of neutrinos, i.e. mu-neutrinos or tau-neutrinos. These neutrinos do not participate in the CC reaction. Therefore real-time experiment is to be sensitive to Neutral Current (NC) reactions. It is a challenge to eliminate environment background as much as possible and to lower the minimum detectable energy to several 100 keV, which will enable observation of Be-7 neutrinos. Target particles of real-time experiments currently running and under construction or planning are electron, deuteron, or argon. The relevant reactions corresponding to CC reaction and some relevant comments on the following targets are described: (1) electron target; (2) deuteron target; and (3) argon target. On-going experiment and future experiments for real-time neutron detection are also outlined.

  2. REAL TIME CONTROL OF URBAN DRAINAGE NETWORKS

    EPA Science Inventory

    Real-time control (RTC) is a custom-designed, computer-assisted management technology for a specific sewerage network to meet the operational objectives of its collection/conveyance system. RTC can operate in several modes, including a mode that is activated during a wet weather ...

  3. [Real-time ultrasonography in neonatal diagnosis].

    PubMed

    Nogués, A; Morales, A; Munguía, C; Pagola, C; Arena, J

    1982-11-01

    Real time ultrasonography is a diagnostic technique very widely used in pediatrics and with specific applications in neonatology. Bedside its use in Neonatal I.C.U. it has many interesting aspects for intraabdominal and intracranial pathology. In some particular conditions this procedure can be the first diagnostic tool. Conventional X-rays can be performed after sonographic data have been analyzed. PMID:7168508

  4. Apparatus Characterizes Transient Voltages in Real Time

    NASA Technical Reports Server (NTRS)

    Medelius, Pedro

    2005-01-01

    is received, a volatile memory is filled with data for a total time of 200 ms. After the data are transferred to nonvolatile memory, the recorder rearms itself within 400 ms to enable recording of subsequent transients. Unfortunately, the recorded data must be retrieved through a serial communication link. Depending on the amount of data recorded, the memory can be filled before retrieval is completed. Although large amounts of data are recorded and retrieved, only a small part of the information (the selected parameters) is usually required. The present transient-voltage recorder provides the required information, without incurring the overhead associated with the recording, storage, and retrieval of complete transient-waveform data. In operation, this apparatus processes transient voltage waveforms in real time to extract and record the selected parameters. An analog-to-digital converter that operates at a speed of as much as 100 mega-samples per second is used to sample a transient waveform. A real-time comparator and peak detector are implemented by use of fast field-programmable gate arrays.

  5. ALMA Correlator Real-Time Data Processor

    NASA Astrophysics Data System (ADS)

    Pisano, J.; Amestica, R.; Perez, J.

    2005-10-01

    The design of a real-time Linux application utilizing Real-Time Application Interface (RTAI) to process real-time data from the radio astronomy correlator for the Atacama Large Millimeter Array (ALMA) is described. The correlator is a custom-built digital signal processor which computes the cross-correlation function of two digitized signal streams. ALMA will have 64 antennas with 2080 signal streams each with a sample rate of 4 giga-samples per second. The correlator's aggregate data output will be 1 gigabyte per second. The software is defined by hard deadlines with high input and processing data rates, while requiring interfaces to non real-time external computers. The designed computer system - the Correlator Data Processor or CDP, consists of a cluster of 17 SMP computers, 16 of which are compute nodes plus a master controller node all running real-time Linux kernels. Each compute node uses an RTAI kernel module to interface to a 32-bit parallel interface which accepts raw data at 64 megabytes per second in 1 megabyte chunks every 16 milliseconds. These data are transferred to tasks running on multiple CPUs in hard real-time using RTAI's LXRT facility to perform quantization corrections, data windowing, FFTs, and phase corrections for a processing rate of approximately 1 GFLOPS. Highly accurate timing signals are distributed to all seventeen computer nodes in order to synchronize them to other time-dependent devices in the observatory array. RTAI kernel tasks interface to the timing signals providing sub-millisecond timing resolution. The CDP interfaces, via the master node, to other computer systems on an external intra-net for command and control, data storage, and further data (image) processing. The master node accesses these external systems utilizing ALMA Common Software (ACS), a CORBA-based client-server software infrastructure providing logging, monitoring, data delivery, and intra-computer function invocation. The software is being developed in tandem

  6. Real Time Radiation Monitoring Using Nanotechnology

    NASA Technical Reports Server (NTRS)

    Li, Jing (Inventor); Wilkins, Richard T. (Inventor); Hanratty, James J. (Inventor); Lu, Yijiang (Inventor)

    2016-01-01

    System and method for monitoring receipt and estimating flux value, in real time, of incident radiation, using two or more nanostructures (NSs) and associated terminals to provide closed electrical paths and to measure one or more electrical property change values .DELTA.EPV, associated with irradiated NSs, during a sequence of irradiation time intervals. Effects of irradiation, without healing and with healing, of the NSs, are separately modeled for first order and second order healing. Change values.DELTA.EPV are related to flux, to cumulative dose received by NSs, and to radiation and healing effectivity parameters and/or.mu., associated with the NS material and to the flux. Flux and/or dose are estimated in real time, based on EPV change values, using measured .DELTA.EPV values. Threshold dose for specified changes of biological origin (usually undesired) can be estimated. Effects of time-dependent radiation flux are analyzed in pre-healing and healing regimes.

  7. Real Time Radiation Exposure And Health Risks

    NASA Technical Reports Server (NTRS)

    Hu, Shaowen; Barzilla, Janet E.; Semones, Edward J.

    2015-01-01

    Radiation from solar particle events (SPEs) poses a serious threat to future manned missions outside of low Earth orbit (LEO). Accurate characterization of the radiation environment in the inner heliosphere and timely monitoring the health risks to crew are essential steps to ensure the safety of future Mars missions. In this project we plan to develop an approach that can use the particle data from multiple satellites and perform near real-time simulations of radiation exposure and health risks for various exposure scenarios. Time-course profiles of dose rates will be calculated with HZETRN and PDOSE from the energy spectrum and compositions of the particles archived from satellites, and will be validated from recent radiation exposure measurements in space. Real-time estimation of radiation risks will be investigated using ARRBOD. This cross discipline integrated approach can improve risk mitigation by providing critical information for risk assessment and medical guidance to crew during SPEs.

  8. Satellite time and frequency transfer (STIFT)

    NASA Technical Reports Server (NTRS)

    Vessot, R. F. C.

    1983-01-01

    The concept of placing a hydrogen maser high stability clock in Earth orbit to provide accurate time and frequency comparisons worldwide to major timing centers and to a large number of radio observatory antenna sites involved in VLBI measurements was studied. The proposal was chiefly directed toward studies and initial hardware designs for time comparisons between hydrogen maser frequency standards and to modifications of the hydrogen maser for long-term use in space.

  9. Time and frequency technology at NIST

    NASA Technical Reports Server (NTRS)

    Sullivan, D. B.

    1994-01-01

    The state of development of advanced timing systems at NIST is described. The work on cesium and rubidium frequency standards, stored-ion frequency standards, diode lasers used to pump such standards, time transfer, and methods for characterizing clocks, oscillators, and time distribution systems is presented. The emphasis is on NIST-developed technology rather than the general state of the art in this field.

  10. United time-frequency spectroscopy for dynamics and global structure.

    PubMed

    Marian, Adela; Stowe, Matthew C; Lawall, John R; Felinto, Daniel; Ye, Jun

    2004-12-17

    Ultrashort laser pulses have thus far been used in two distinct modes. In the time domain, the pulses have allowed probing and manipulation of dynamics on a subpicosecond time scale. More recently, phase stabilization has produced optical frequency combs with absolute frequency reference across a broad bandwidth. Here we combine these two applications in a spectroscopic study of rubidium atoms. A wide-bandwidth, phase-stabilized femtosecond laser is used to monitor the real-time dynamic evolution of population transfer. Coherent pulse accumulation and quantum interference effects are observed and well modeled by theory. At the same time, the narrow linewidth of individual comb lines permits a precise and efficient determination of the global energy-level structure, providing a direct connection among the optical, terahertz, and radio-frequency domains. The mechanical action of the optical frequency comb on the atomic sample is explored and controlled, leading to precision spectroscopy with an appreciable reduction in systematic errors. PMID:15550622

  11. Object detection in real-time

    NASA Astrophysics Data System (ADS)

    Solder, Ulrich; Graefe, Volker

    1991-03-01

    An algorithm working on monocular gray-scale image sequences for object detection combined with a road tracker is presented. This algorithm appropriate for the real-time demands of an autonomous car driving with speeds over 40 km/h may be used for triggering obstacle avoidance maneuvers such as coming to a safe stop automatically in front of an obstacle or following another car. Moving and static objects have been detected in real-world experiments on various types of roads even under unfavorable weather conditions. . Morgenthaler and

  12. Real Time RF Simulator (RTS) and control

    SciTech Connect

    Cancelo, G.; Armiento, C.; Treptow, K.; Vignoni, A.; Zmuda, T.; /Fermilab

    2008-10-01

    The multi-cavity RTS allows LLRF algorithm development and lab testing prior to commissioning with real cavities and cryomodules. The RTS is a valuable tool since it models the functions, errors and disturbances of real RF systems. The advantage of a RTS over an off-line simulator is that it can be implemented on the actual LLRF hardware, on the same FPGA and processor, and run at the same speed of the LLRF control loop. Additionally the RTS can be shared by collaborators who do not have access to RF systems or when the systems are not available to LLRF engineers. The RTS simulator incorporates hardware, firmware and software errors and limitations of a real implementation, which would be hard to identify and time consuming to model in off-line simulations.

  13. Robust Real-Time Wide-Area Differential GPS Navigation

    NASA Technical Reports Server (NTRS)

    Yunck, Thomas P. (Inventor); Bertiger, William I. (Inventor); Lichten, Stephen M. (Inventor); Mannucci, Anthony J. (Inventor); Muellerschoen, Ronald J. (Inventor); Wu, Sien-Chong (Inventor)

    1998-01-01

    The present invention provides a method and a device for providing superior differential GPS positioning data. The system includes a group of GPS receiving ground stations covering a wide area of the Earth's surface. Unlike other differential GPS systems wherein the known position of each ground station is used to geometrically compute an ephemeris for each GPS satellite. the present system utilizes real-time computation of satellite orbits based on GPS data received from fixed ground stations through a Kalman-type filter/smoother whose output adjusts a real-time orbital model. ne orbital model produces and outputs orbital corrections allowing satellite ephemerides to be known with considerable greater accuracy than from die GPS system broadcasts. The modeled orbits are propagated ahead in time and differenced with actual pseudorange data to compute clock offsets at rapid intervals to compensate for SA clock dither. The orbital and dock calculations are based on dual frequency GPS data which allow computation of estimated signal delay at each ionospheric point. These delay data are used in real-time to construct and update an ionospheric shell map of total electron content which is output as part of the orbital correction data. thereby allowing single frequency users to estimate ionospheric delay with an accuracy approaching that of dual frequency users.

  14. Real Time Pricing and the Real Live Firm

    SciTech Connect

    Moezzi, Mithra; Goldman, Charles; Sezgen, Osman; Bharvirkar, Ranjit; Hopper, Nicole

    2004-05-26

    Energy economists have long argued the benefits of real time pricing (RTP) of electricity. Their basis for modeling customers response to short-term fluctuations in electricity prices are based on theories of rational firm behavior, where management strives to minimize operating costs and optimize profit, and labor, capital and energy are potential substitutes in the firm's production function. How well do private firms and public sector institutions operating conditions, knowledge structures, decision-making practices, and external relationships comport with these assumptions and how might this impact price response? We discuss these issues on the basis of interviews with 29 large (over 2 MW) industrial, commercial, and institutional customers in the Niagara Mohawk Power Corporation service territory that have faced day-ahead electricity market prices since 1998. We look at stories interviewees told about why and how they respond to RTP, why some customers report that they can't, and why even if they can, they don't. Some firms respond as theorized, and we describe their load curtailment strategies. About half of our interviewees reported that they were unable to either shift or forego electricity consumption even when prices are high ($0.50/kWh). Reasons customers gave for why they weren't price-responsive include implicit value placed on reliability, pricing structures, lack of flexibility in adjusting production inputs, just-in-time practices, perceived barriers to onsite generation, and insufficient time. We draw these observations into a framework that could help refine economic theory of dynamic pricing by providing real-world descriptions of how firms behave and why.

  15. Real Time Correction of Aircraft Flight Fonfiguration

    NASA Technical Reports Server (NTRS)

    Schipper, John F. (Inventor)

    2009-01-01

    Method and system for monitoring and analyzing, in real time, variation with time of an aircraft flight parameter. A time-dependent recovery band, defined by first and second recovery band boundaries that are spaced apart at at least one time point, is constructed for a selected flight parameter and for a selected time recovery time interval length .DELTA.t(FP;rec). A flight parameter, having a value FP(t=t.sub.p) at a time t=t.sub.p, is likely to be able to recover to a reference flight parameter value FP(t';ref), lying in a band of reference flight parameter values FP(t';ref;CB), within a time interval given by t.sub.p.ltoreq.t'.ltoreq.t.sub.p.DELTA.t(FP;rec), if (or only if) the flight parameter value lies between the first and second recovery band boundary traces.

  16. Real time gamma-ray signature identifier

    DOEpatents

    Rowland, Mark; Gosnell, Tom B.; Ham, Cheryl; Perkins, Dwight; Wong, James

    2012-05-15

    A real time gamma-ray signature/source identification method and system using principal components analysis (PCA) for transforming and substantially reducing one or more comprehensive spectral libraries of nuclear materials types and configurations into a corresponding concise representation/signature(s) representing and indexing each individual predetermined spectrum in principal component (PC) space, wherein an unknown gamma-ray signature may be compared against the representative signature to find a match or at least characterize the unknown signature from among all the entries in the library with a single regression or simple projection into the PC space, so as to substantially reduce processing time and computing resources and enable real-time characterization and/or identification.

  17. A real-time impurity solver for DMFT

    NASA Astrophysics Data System (ADS)

    Kim, Hyungwon; Aron, Camille; Han, Jong E.; Kotliar, Gabriel

    Dynamical mean-field theory (DMFT) offers a non-perturbative approach to problems with strongly correlated electrons. The method heavily relies on the ability to numerically solve an auxiliary Anderson-type impurity problem. While powerful Matsubara-frequency solvers have been developed over the past two decades to tackle equilibrium situations, the status of real-time impurity solvers that could compete with Matsubara-frequency solvers and be readily generalizable to non-equilibrium situations is still premature. We present a real-time solver which is based on a quantum Master equation description of the dissipative dynamics of the impurity and its exact diagonalization. As a benchmark, we illustrate the strengths of our solver in the context of the equilibrium Mott-insulator transition of the one-band Hubbard model and compare it with iterative perturbation theory (IPT) method. Finally, we discuss its direct application to a nonequilibrium situation.

  18. Real-Time Seismology in Portugal

    NASA Astrophysics Data System (ADS)

    Custodio, S.; Marreiros, C.; Carvalho, S.; Vales, D.; Lima, V.; Carrilho, F.

    2012-12-01

    Portugal is located next to the plate boundary between Eurasia (Iberia) and Africa (Nubia). The country has been repeatedly affected by some of the largest earthquakes, both onshore and offshore, in the historical European record, including the largest historical European earthquake, the great Lisbon earthquake of 1755 (~M8.5). The Portuguese territory has suffered directly the consequences of strong ground shaking (collapse of buildings, etc) and also some of the most destructive consequences of earthquakes (e.g. tsunamis, fires, etc). However, the rate of tectonic deformation in the Portuguese territory is low (the Eurasian-African plates converge at a rate of ~ 5 mm/yr), which results in long recurrence intervals between earthquakes. This low to moderate rate of seismic activity has two major negative effects: 1) it is difficult to study the regional seismo-tectonics with traditional passive methods; 2) the population is little aware of earthquake risk and unprepared to react in case of disaster. In this scenario, real-time seismology is key to monitoring earthquake crisis in real-time, providing early warnings about potentially destructive events, and assisting in the channeling of recovery efforts in case of disaster. In this paper we will present the real-time algorithms implemented at Instituto de Meteorologia (IM), the institution responsible for seismic monitoring in Portugal. In particular, we will focus on the following aspects: 1) Data collection and real-time transmission to the headquarters. Broadband seismological stations are owned and operated by five different institutions. The last years have witnessed an effort for integration, and presently most data arrives at IM lab in real-time. 2) Earthquake location and local magnitude determination. Data is automatically analyzed in order to obtain a first earthquake hypocenter and ML. While this process is mostly automatic, it still requires the revision by an operator, who is available 24h. 3

  19. Architecture of the APS real-time orbit feedback system.

    SciTech Connect

    Carwardine, J. A.; Lenkszus, F. R.

    1997-11-21

    The APS Real-Time Orbit Feedback System is designed to stabilize the orbit of the stored positron beam against low-frequency sources such as mechanical vibration and power supply ripple. A distributed array of digital signal processors is used to measure the orbit and compute corrections at a 1kHz rate. The system also provides extensive beam diagnostic tools. This paper describes the architectural aspects of the system and describes how the orbit correction algorithms are implemented.

  20. Real-Time, Polyphase-FFT, 640-MHz Spectrum Analyzer

    NASA Technical Reports Server (NTRS)

    Zimmerman, George A.; Garyantes, Michael F.; Grimm, Michael J.; Charny, Bentsian; Brown, Randy D.; Wilck, Helmut C.

    1994-01-01

    Real-time polyphase-fast-Fourier-transform, polyphase-FFT, spectrum analyzer designed to aid in detection of multigigahertz radio signals in two 320-MHz-wide polarization channels. Spectrum analyzer divides total spectrum of 640 MHz into 33,554,432 frequency channels of about 20 Hz each. Size and cost of polyphase-coefficient memory substantially reduced and much of processing loss of windowed FFTs eliminated.

  1. "Fast" Is Not "Real-Time": Designing Effective Real-Time AI Systems

    NASA Astrophysics Data System (ADS)

    O'Reilly, Cindy A.; Cromarty, Andrew S.

    1985-04-01

    Realistic practical problem domains (such as robotics, process control, and certain kinds of signal processing) stand to benefit greatly from the application of artificial intelligence techniques. These problem domains are of special interest because they are typified by complex dynamic environments in which the ability to select and initiate a proper response to environmental events in real time is a strict prerequisite to effective environmental interaction. Artificial intelligence systems developed to date have been sheltered from this real-time requirement, however, largely by virtue of their use of simplified problem domains or problem representations. The plethora of colloquial and (in general) mutually inconsistent interpretations of the term "real-time" employed by workers in each of these domains further exacerbates the difficul-ties in effectively applying state-of-the-art problem solving tech-niques to time-critical problems. Indeed, the intellectual waters are by now sufficiently muddied that the pursuit of a rigorous treatment of intelligent real-time performance mandates the redevelopment of proper problem perspective on what "real-time" means, starting from first principles. We present a simple but nonetheless formal definition of real-time performance. We then undertake an analysis of both conventional techniques and AI technology with respect to their ability to meet substantive real-time performance criteria. This analysis provides a basis for specification of problem-independent design requirements for systems that would claim real-time performance. Finally, we discuss the application of these design principles to a pragmatic problem in real-time signal understanding.

  2. Real-time earthquake data feasible

    NASA Astrophysics Data System (ADS)

    Bush, Susan

    Scientists agree that early warning devices and monitoring of both Hurricane Hugo and the Mt. Pinatubo volcanic eruption saved thousands of lives. What would it take to develop this sort of early warning and monitoring system for earthquake activity?Not all that much, claims a panel assigned to study the feasibility, costs, and technology needed to establish a real-time earthquake monitoring (RTEM) system. The panel, drafted by the National Academy of Science's Committee on Seismology, has presented its findings in Real-Time Earthquake Monitoring. The recently released report states that “present technology is entirely capable of recording and processing data so as to provide real-time information, enabling people to mitigate somewhat the earthquake disaster.” RTEM systems would consist of two parts—an early warning system that would give a few seconds warning before severe shaking, and immediate postquake information within minutes of the quake that would give actual measurements of the magnitude. At this time, however, this type of warning system has not been addressed at the national level for the United States and is not included in the National Earthquake Hazard Reduction Program, according to the report.

  3. Distributed Real-Time Computing with Harness

    SciTech Connect

    Di Saverio, Emanuele; Cesati, Marco; Di Biagio, Christian; Pennella, Guido; Engelmann, Christian

    2007-01-01

    Modern parallel and distributed computing solutions are often built onto a ''middleware'' software layer providing a higher and common level of service between computational nodes. Harness is an adaptable, plugin-based middleware framework for parallel and distributed computing. This paper reports recent research and development results of using Harness for real-time distributed computing applications in the context of an industrial environment with the needs to perform several safety critical tasks. The presented work exploits the modular architecture of Harness in conjunction with a lightweight threaded implementation to resolve several real-time issues by adding three new Harness plug-ins to provide a prioritized lightweight execution environment, low latency communication facilities, and local timestamped event logging.

  4. Visualizations for Real-time Pricing Demonstration

    SciTech Connect

    Marinovici, Maria C.; Hammerstrom, Janelle L.; Widergren, Steven E.; Dayley, Greg K.

    2014-10-13

    In this paper, the visualization tools created for monitoring the operations of a real-time pricing demonstration system that runs at a distribution feeder level are presented. The information these tools provide gives insights into demand behavior from automated price responsive devices, distribution feeder characteristics, impact of weather on system’s development, and other significant dynamics. Given the large number of devices that bid into a feeder-level real-time electricity market, new techniques are explored to summarize the present state of the system and contrast that with previous trends as well as future projections. To better understand the system behavior and correctly inform decision-making procedures, effective visualization of the data is imperative.

  5. AMON: Transition to real-time operations

    NASA Astrophysics Data System (ADS)

    Cowen, D. F.; Keivani, A.; Tešić, G.

    2016-04-01

    The Astrophysical Multimessenger Observatory Network (AMON) will link the world's leading high-energy neutrino, cosmic-ray, gamma-ray and gravitational wave observatories by performing real-time coincidence searches for multimessenger sources from observatories' subthreshold data streams. The resulting coincidences will be distributed to interested parties in the form of electronic alerts for real-time follow-up observation. We will present the science case, design elements, current and projected partner observatories, status of the AMON project, and an initial AMON-enabled analysis. The prototype of the AMON server has been online since August 2014 and processing archival data. Currently, we are deploying new high-uptime servers and will be ready to start issuing alerts as early as winter 2015/16.

  6. Real-Time Imaging of Quantum Entanglement

    PubMed Central

    Fickler, Robert; Krenn, Mario; Lapkiewicz, Radek; Ramelow, Sven; Zeilinger, Anton

    2013-01-01

    Quantum Entanglement is widely regarded as one of the most prominent features of quantum mechanics and quantum information science. Although, photonic entanglement is routinely studied in many experiments nowadays, its signature has been out of the grasp for real-time imaging. Here we show that modern technology, namely triggered intensified charge coupled device (ICCD) cameras are fast and sensitive enough to image in real-time the effect of the measurement of one photon on its entangled partner. To quantitatively verify the non-classicality of the measurements we determine the detected photon number and error margin from the registered intensity image within a certain region. Additionally, the use of the ICCD camera allows us to demonstrate the high flexibility of the setup in creating any desired spatial-mode entanglement, which suggests as well that visual imaging in quantum optics not only provides a better intuitive understanding of entanglement but will improve applications of quantum science. PMID:23715056

  7. Real-time remote scientific model validation

    NASA Technical Reports Server (NTRS)

    Frainier, Richard; Groleau, Nicolas

    1994-01-01

    This paper describes flight results from the use of a CLIPS-based validation facility to compare analyzed data from a space life sciences (SLS) experiment to an investigator's preflight model. The comparison, performed in real-time, either confirms or refutes the model and its predictions. This result then becomes the basis for continuing or modifying the investigator's experiment protocol. Typically, neither the astronaut crew in Spacelab nor the ground-based investigator team are able to react to their experiment data in real time. This facility, part of a larger science advisor system called Principal Investigator in a Box, was flown on the space shuttle in October, 1993. The software system aided the conduct of a human vestibular physiology experiment and was able to outperform humans in the tasks of data integrity assurance, data analysis, and scientific model validation. Of twelve preflight hypotheses associated with investigator's model, seven were confirmed and five were rejected or compromised.

  8. REAL TIME BETATRON TUNE CONTROL IN RHIC.

    SciTech Connect

    SCHULTHEISS,C.; CAMERON,P.; MARUSIC,A.; VAN ZEIJTS,J.

    2002-06-02

    Precise control of the betatron tunes is necessary to preserve proton polarization during the RHIC ramp. In addition, control of the tunes during beam deceleration is necessary due to hysteresis in the superconducting magnets. A real-time feedback system to control the betatron tunes during ramping has been developed for use in RHIC. This paper describes this system and presents the results from commissioning the system during the polarized proton run.

  9. Real time computer controlled weld skate

    NASA Technical Reports Server (NTRS)

    Wall, W. A., Jr.

    1977-01-01

    A real time, adaptive control, automatic welding system was developed. This system utilizes the general case geometrical relationships between a weldment and a weld skate to precisely maintain constant weld speed and torch angle along a contoured workplace. The system is compatible with the gas tungsten arc weld process or can be adapted to other weld processes. Heli-arc cutting and machine tool routing operations are possible applications.

  10. Real-time radiographic inspection facility

    NASA Technical Reports Server (NTRS)

    Roberts, E., Jr.

    1977-01-01

    A real time radiographic inspection facility has been developed for nondestructive evaluation applications. It consists of an X-ray source, an X-ray sensitive television imaging system, an electronic analog image processing system, and a digital image processing system. The digital image processing system is composed of a computer with the necessary software to drive the overall facility. Descriptions are given of the design strategy, the facility's components, and its current capabilities.

  11. Real-time RGBD SLAM system

    NASA Astrophysics Data System (ADS)

    Czupryński, BłaŻej; Strupczewski, Adam

    2015-09-01

    A real-time tracking and mapping SLAM system is presented. The developed system uses input from an RGBD sensor and tracks the camera pose from frame to frame. The tracking is based on matched feature points and is performed with respect to selected keyframes. The system is robust and scalable, as an arbitrary number of keyframes can be chosen for visualization and tracking depending on the desired accuracy and speed. The presented system is also a good platform for further research.

  12. Real time closed orbit correction system

    SciTech Connect

    Yu, L.H.; Biscardi, R.; Bittner, J.; Bozoki, E.; Galayda, J.; Krinsky, S.; Nawrocky, R.; Singh, O.; Vignola, G.

    1989-01-01

    We describe a global closed orbit feedback experiment, based upon a real time harmonic analysis of both the orbit movement and the correction magnetic fields. The feedback forces the coefficients of a few harmonics near the betatron tune to vanish, and significantly improves the global orbit stability. We present the results of the experiment in the UV ring using 4 detectors and 4 trims, in which maximum observed displacement was reduced by a factor of between 3 and 4. 4 refs., 3 figs.

  13. Real-Time X-Ray Inspection

    NASA Technical Reports Server (NTRS)

    Bulthuis, Ronald V.

    1988-01-01

    X-ray imaging instrument adapted to continuous scanning. Modern version of fluoroscope enables rapid x-ray inspection of parts. Developed for detection of buckling in insulated ducts. Uses radiation from radioactive gadolinium or thallium source. Instrument weighs only 6 1/2 lb. Quickly scanned by hand along duct surface, providing real-time image. Based on Lixiscope, developed at Goddard Space Flight Center.

  14. Portable real time neutron spectrometry II

    NASA Astrophysics Data System (ADS)

    Maurer, R. H.; Roth, D. R.; Fainchtein, R.; Goldsten, J. O.; Kinnison, J. D.

    2000-01-01

    We describe the continued development of a portable, real-time neutron spectrometer. The spectrometer is composed of two distinct detector systems: a Helium 3 gas filled proportional counter for the lower neutron energy interval between 20 KeV and 2 MeV and a bulk silicon solid state detector for the higher energy interval between 2 MeV and 500 MeV. Modeling and experimental results with mono-energetic neutron beams are reported. .

  15. Real-time contingency handling in MAESTRO

    NASA Technical Reports Server (NTRS)

    Britt, Daniel L.; Geoffroy, Amy L.

    1992-01-01

    A scheduling and resource management system named MAESTRO was interfaced with a Space Station Module Power Management and Distribution (SSM/PMAD) breadboard at MSFC. The combined system serves to illustrate the integration of planning, scheduling, and control in a realistic, complex domain. This paper briefly describes the functional elements of the combined system, including normal and contingency operational scenarios, then focusses on the method used by the scheduler to handle real-time contingencies.

  16. Operational real-time GPS-enhanced earthquake early warning

    NASA Astrophysics Data System (ADS)

    Grapenthin, R.; Johanson, I. A.; Allen, R. M.

    2014-10-01

    Moment magnitudes for large earthquakes (Mw≥7.0) derived in real time from near-field seismic data can be underestimated due to instrument limitations, ground tilting, and saturation of frequency/amplitude-magnitude relationships. Real-time high-rate GPS resolves the buildup of static surface displacements with the S wave arrival (assuming nonsupershear rupture), thus enabling the estimation of slip on a finite fault and the event's geodetic moment. Recently, a range of high-rate GPS strategies have been demonstrated on off-line data. Here we present the first operational system for real-time GPS-enhanced earthquake early warning as implemented at the Berkeley Seismological Laboratory (BSL) and currently analyzing real-time data for Northern California. The BSL generates real-time position estimates operationally using data from 62 GPS stations in Northern California. A fully triangulated network defines 170+ station pairs processed with the software trackRT. The BSL uses G-larmS, the Geodetic Alarm System, to analyze these positioning time series and determine static offsets and preevent quality parameters. G-larmS derives and broadcasts finite fault and magnitude information through least-squares inversion of the static offsets for slip based on a priori fault orientation and location information. This system tightly integrates seismic alarm systems (CISN-ShakeAlert, ElarmS-2) as it uses their P wave detections to trigger its processing; quality control runs continuously. We use a synthetic Hayward Fault earthquake scenario on real-time streams to demonstrate recovery of slip and magnitude. Reanalysis of the Mw7.2 El Mayor-Cucapah earthquake tests the impact of dynamic motions on offset estimation. Using these test cases, we explore sensitivities to disturbances of a priori constraints (origin time, location, and fault strike/dip).

  17. The Raptor Real-Time Processing Architecture

    NASA Astrophysics Data System (ADS)

    Galassi, M.; Starr, D.; Wozniak, P.; Brozdin, K.

    The primary goal of Raptor is ambitious: to identify interesting optical transients from very wide field of view telescopes in real time, and then to quickly point the higher resolution Raptor ``fovea'' cameras and spectrometer to the location of the optical transient. The most interesting of Raptor's many applications is the real-time search for orphan optical counterparts of Gamma Ray Bursts. The sequence of steps (data acquisition, basic calibration, source extraction, astrometry, relative photometry, the smarts of transient identification and elimination of false positives, telescope pointing feedback, etc.) is implemented with a ``component'' approach. All basic elements of the pipeline functionality have been written from scratch or adapted (as in the case of SExtractor for source extraction) to form a consistent modern API operating on memory resident images and source lists. The result is a pipeline which meets our real-time requirements and which can easily operate as a monolithic or distributed processing system. Finally, the Raptor architecture is entirely based on free software (sometimes referred to as ``open source'' software). In this paper we also discuss the interplay between various free software technologies in this type of astronomical problem.

  18. Raptor -- Mining the Sky in Real Time

    NASA Astrophysics Data System (ADS)

    Galassi, M.; Borozdin, K.; Casperson, D.; McGowan, K.; Starr, D.; White, R.; Wozniak, P.; Wren, J.

    2004-06-01

    The primary goal of Raptor is ambitious: to identify interesting optical transients from very wide field of view telescopes in real time, and then to quickly point the higher resolution Raptor ``fovea'' cameras and spectrometer to the location of the optical transient. The most interesting of Raptor's many applications is the real-time search for orphan optical counterparts of Gamma Ray Bursts. The sequence of steps (data acquisition, basic calibration, source extraction, astrometry, relative photometry, the smarts of transient identification and elimination of false positives, telescope pointing feedback...) is implemented with a ``component'' aproach. All basic elements of the pipeline functionality have been written from scratch or adapted (as in the case of SExtractor for source extraction) to form a consistent modern API operating on memory resident images and source lists. The result is a pipeline which meets our real-time requirements and which can easily operate as a monolithic or distributed processing system. Finally: the Raptor architecture is entirely based on free software (sometimes referred to as "open source" software). In this paper we also discuss the interplay between various free software technologies in this type of astronomical problem.

  19. Steering a mobile robot in real time

    NASA Astrophysics Data System (ADS)

    Chuah, Mei C.; Fennema, Claude L., Jr.

    1994-10-01

    Using computer vision for mobile robot navigation has been of interest since the 1960s. This interest is evident in even the earliest robot projects: at SRI International (`Shakey') and at the Stanford University (`Stanford Cart'). These pioneering projects provided a foundation for late work but fell far short of providing real time solutions. Since the mid 1980s, the ARPA sponsored ALV and UGV projects have established a need for real time navigation. To achieve the necessary speed, some researchers have focused on building faster hardware; others have turned to the use of new computational architectures, such as neural nets. The work described in this paper uses another approach that has become known as `perceptual servoing.' Previously reported results show that perceptual servoing is both fast and accurate when used to steer vehicles equipped with precise odometers. When the instrumentation on the vehicle does not give precise measurements of distance traveled, as could be the case for a vehicle traveling on ice or mud, new techniques are required to accommodate the reduced ability to make accurate predictions about motion and control. This paper presents a method that computes estimates of distance traveled using landmarks and path information. The new method continues to perform in real time using modest computational facilities, and results demonstrate the effects of the new implementation on steering accuracy.

  20. Real-time monitoring system for microfluidics

    NASA Astrophysics Data System (ADS)

    Sapuppo, F.; Cantelli, G.; Fortuna, L.; Arena, P.; Bucolo, M.

    2007-05-01

    A new non-invasive real-time system for the monitoring and control of microfluidodynamic phenomena is proposed. The general purpose design of such system is suitable for in vitro and in vivo experimental setup and therefore for microfluidic application in the biomedical field such as lab-on-chip and for research studies in the field of microcirculation. The system consists of an ad hoc optical setup for image magnification providing images suitable for image acquisition and processing. The optic system was designed and developed using discrete opto-mechanic components mounted on a breadboard in order to provide an optic path accessible at any point where the information needs to be acquired. The optic sensing, acquisition, and processing were performed using an integrated vision system based on the Cellular Nonlinear Networks (CNNs) analogic technology called Focal Plane Processor (FPP, Eye-RIS, Anafocus) and inserted in the optic path. Ad hoc algorithms were implemented for the real-time analysis and extraction of fluido-dynamic parameters in micro-channels. They were tested on images recorded during in vivo microcirculation experiments on hamsters and then they were applied on images optically acquired and processed in real-time during in vitro experiments on a continuous microfluidic device (serpentine mixer, ThinXXS) with a two-phase fluid.

  1. Real-time realistic skin translucency.

    PubMed

    Jimenez, Jorge; Whelan, David; Sundstedt, Veronica; Gutierrez, Diego

    2010-01-01

    Diffusion theory allows the production of realistic skin renderings. The dipole and multipole models allow for solving challenging diffusion-theory equations efficiently. By using texture-space diffusion, a Gaussian-based approximation, and programmable graphics hardware, developers can create real-time, photorealistic skin renderings. Performing this diffusion in screen space offers advantages that make diffusion approximation practical in scenarios such as games, where having the best possible performance is crucial. However, unlike the texture-space counterpart, the screen-space approach can't simulate transmittance of light through thin geometry; it yields unrealistic results in those cases. A new transmittance algorithm turns the screen-space approach into an efficient global solution, capable of simulating both reflectance and transmittance of light through a multilayered skin model. The transmittance calculations are derived from physical equations, which are implemented through simple texture access. The method performs in real time, requiring no additional memory usage and only minimal additional processing power and memory bandwidth. Despite its simplicity, this practical model manages to reproduce the look of images rendered with other techniques (both offline and real time) such as photon mapping or diffusion approximation. PMID:20650726

  2. Software Analyzes Complex Systems in Real Time

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Expert system software programs, also known as knowledge-based systems, are computer programs that emulate the knowledge and analytical skills of one or more human experts, related to a specific subject. SHINE (Spacecraft Health Inference Engine) is one such program, a software inference engine (expert system) designed by NASA for the purpose of monitoring, analyzing, and diagnosing both real-time and non-real-time systems. It was developed to meet many of the Agency s demanding and rigorous artificial intelligence goals for current and future needs. NASA developed the sophisticated and reusable software based on the experience and requirements of its Jet Propulsion Laboratory s (JPL) Artificial Intelligence Research Group in developing expert systems for space flight operations specifically, the diagnosis of spacecraft health. It was designed to be efficient enough to operate in demanding real time and in limited hardware environments, and to be utilized by non-expert systems applications written in conventional programming languages. The technology is currently used in several ongoing NASA applications, including the Mars Exploration Rovers and the Spacecraft Health Automatic Reasoning Pilot (SHARP) program for the diagnosis of telecommunication anomalies during the Neptune Voyager Encounter. It is also finding applications outside of the Space Agency.

  3. Turning movement estimation in real time

    SciTech Connect

    Martin, P.T.

    1997-08-01

    Fast processors offer exciting opportunities for real-time traffic monitoring. Conventional transportation planning models that assume stable and predictable travel patterns do not lend themselves to on-line traffic forecasting. This paper describes how a new traffic flow inference model has the potential to determine comprehensive flow information in real time. Its philosophical basis is borrowed from the field of operational research, where it has been used for optimizing water and electricity flows. This paper shows how road traffic turning movement flows can be estimated from link detected flows at small recurrent intervals, in real time. The paper details the formulation of the problem, outlines the structure of the data set that provides the detector data for the model input and observed turning flows for the model evaluation. The theoretical principles that define the model are described briefly. Turning movement flow estimates, at 5-min intervals, from two independent surveys are presented and analyzed. The results show an overall mean coefficient of determination (r{sup 2}) of 79--82% between observed and modeled turning movement flows.

  4. Real-time detection of airborne chemicals

    NASA Astrophysics Data System (ADS)

    Hartenstein, Steven D.; Tremblay, Paul L. A.; Fryer, Michael O.; Kaser, Timothy

    1999-02-01

    Accurate, real time air quality measurements are difficult to make, because real time sensors for some gas species are not specific to a single gas. For example, some carbon dioxide sensors react to hydrogen sulfide. By combining the response of several types of real time gas sensors the Real-time Air Quality Monitoring System (RAQMS) accurately measures many different gases. The sensor suite for the INEEL's Real-time Air Quality Monitoring System (RAQMS) incudes seven, inexpensive, commercially-available chemical sensors for gases associated with air quality. These chemical sensors are marketed as devices to measure carbon dioxide, hydrogen sulfide, carbon monoxide, sulfur dioxide, nitrogen dioxide, water vapor and volatile organic compounds (VOC's). However, these chemical sensors respond to more than a single compound, e.g. both the VOC and the carbon dioxide sensors respond strongly to methane. This multiple sensor response to a given chemical is used to advantage in the RAQMS system, as patterns of responses by the sensors were found to be unique and distinguishable for several chemicals. Therefore, there is the potential that the seven sensors combined output can: (1) provide more accurate measurements of the advertized gases and (2) estimate the presence and quantity of additional gases. The patterns of sensor response can be thought of as clusters of data points in a seven dimensional space. One dimension for each sensor's output. For all of the gases tested, these clusters were separated enough that good quantitative results were obtained. As an example, the prototype RAQMS is able to distinguish methane from butane and predict accurate concentrations of both gases. A mathematical technique for estimating probability density functions from random samples is used to distinguish the data clusters from each other and to make gas concentration estimates. Bayes optimal estimates of gas concentration are calculated using the probability density function. The

  5. [Development of real-time CT fluoroscopy].

    PubMed

    Katada, K; Anno, H; Takeshita, G; Ogura, Y; Koga, S; Ida, Y; Nonomura, K; Kanno, T; Ohashi, A; Sata, S

    1994-10-25

    A new CT system that permits real-time monitoring of CT images was developed. Phantom and volunteer studies revealed that the images were displayed at a rate of six per second with a delay time of 0.83 second with clinically sufficient resolution (256 x 256) using the newly developed fast image processor and partial-reconstruction algorithm. The clinical trial of stereotactic aspiration of intracerebral hematoma was successful. The initial trial with CT fluoroscopy revealed potential usefulness of the system in biopsy and other CT-guided interventions. PMID:9261196

  6. Real-time optical fiber dosimeter probe

    NASA Astrophysics Data System (ADS)

    Croteau, André; Caron, Serge; Rink, Alexandra; Jaffray, David; Mermut, Ozzy

    2011-03-01

    There is a pressing need for a passive optical fiber dosimeter probe for use in real-time monitoring of radiation dose delivered to clinical radiation therapy patients. An optical fiber probe using radiochromic material has been designed and fabricated based on a thin film of the radiochromic material on a dielectric mirror. Measurements of the net optical density vs. time before, during, and after irradiation at a rate of 500cGy/minute to a total dose of 5 Gy were performed. Net optical densities increased from 0.2 to 2.0 for radiochromic thin film thicknesses of 2 to 20 μm, respectively.

  7. Acting to gain information: Real-time reasoning meets real-time perception

    NASA Technical Reports Server (NTRS)

    Rosenschein, Stan

    1994-01-01

    Recent advances in intelligent reactive systems suggest new approaches to the problem of deriving task-relevant information from perceptual systems in real time. The author will describe work in progress aimed at coupling intelligent control mechanisms to real-time perception systems, with special emphasis on frame rate visual measurement systems. A model for integrated reasoning and perception will be discussed, and recent progress in applying these ideas to problems of sensor utilization for efficient recognition and tracking will be described.

  8. Machine learning for real time remote detection

    NASA Astrophysics Data System (ADS)

    Labbé, Benjamin; Fournier, Jérôme; Henaff, Gilles; Bascle, Bénédicte; Canu, Stéphane

    2010-10-01

    Infrared systems are key to providing enhanced capability to military forces such as automatic control of threats and prevention from air, naval and ground attacks. Key requirements for such a system to produce operational benefits are real-time processing as well as high efficiency in terms of detection and false alarm rate. These are serious issues since the system must deal with a large number of objects and categories to be recognized (small vehicles, armored vehicles, planes, buildings, etc.). Statistical learning based algorithms are promising candidates to meet these requirements when using selected discriminant features and real-time implementation. This paper proposes a new decision architecture benefiting from recent advances in machine learning by using an effective method for level set estimation. While building decision function, the proposed approach performs variable selection based on a discriminative criterion. Moreover, the use of level set makes it possible to manage rejection of unknown or ambiguous objects thus preserving the false alarm rate. Experimental evidences reported on real world infrared images demonstrate the validity of our approach.

  9. Subsystem real-time time dependent density functional theory

    NASA Astrophysics Data System (ADS)

    Krishtal, Alisa; Ceresoli, Davide; Pavanello, Michele

    2015-04-01

    We present the extension of Frozen Density Embedding (FDE) formulation of subsystem Density Functional Theory (DFT) to real-time Time Dependent Density Functional Theory (rt-TDDFT). FDE is a DFT-in-DFT embedding method that allows to partition a larger Kohn-Sham system into a set of smaller, coupled Kohn-Sham systems. Additional to the computational advantage, FDE provides physical insight into the properties of embedded systems and the coupling interactions between them. The extension to rt-TDDFT is done straightforwardly by evolving the Kohn-Sham subsystems in time simultaneously, while updating the embedding potential between the systems at every time step. Two main applications are presented: the explicit excitation energy transfer in real time between subsystems is demonstrated for the case of the Na4 cluster and the effect of the embedding on optical spectra of coupled chromophores. In particular, the importance of including the full dynamic response in the embedding potential is demonstrated.

  10. Shuttle time and frequency transfer experiment

    NASA Technical Reports Server (NTRS)

    Allan, D. W.; Alley, C. O.; Decher, R.; Vessot, R. F. C.; Winkler, G. M. R.

    1980-01-01

    A proposed space shuttle experiment to demonstrate techniques for global high precision comparison of clocks and primary frequency standards is described. The experiment, using transmitted microwave and pulsed laser signals, compared a hydrogen maser clock onboard the space shuttle with a clock in a ground station in order to demonstrate time transfer with accuracies of 1 nsec or better and frequency comparison at the 10 to the -14th power accuracy level.

  11. A real-time software backend for the GMRT

    NASA Astrophysics Data System (ADS)

    Roy, Jayanta; Gupta, Yashwant; Pen, Ue-Li; Peterson, Jeffrey B.; Kudale, Sanjay; Kodilkar, Jitendra

    2010-08-01

    The new era of software signal processing has a large impact on radio astronomy instrumentation. Our design and implementation of a 32 antennae, 33 MHz, dual polarization, fully real-time software backend for the GMRT, using only off-the-shelf components, is an example of this. We have built a correlator and a beamformer, using PCI-based ADC cards and a Linux cluster of 48 nodes with dual gigabit inter-node connectivity for real-time data transfer requirements. The highly optimized compute pipeline uses cache efficient, multi-threaded parallel code, with the aid of vectorized processing. This backend allows flexibility in final time and frequency resolutions, and the ability to implement algorithms for radio frequency interference rejection. Our approach has allowed relatively rapid development of a fairly sophisticated and flexible backend receiver system for the GMRT, which will greatly enhance the productivity of the telescope. In this paper we describe some of the first lights using this software processing pipeline. We believe this is the first instance of such a real-time observatory backend for an intermediate sized array like the GMRT.

  12. Modeling fibril fragmentation in real-time

    NASA Astrophysics Data System (ADS)

    Tan, Pengzhen; Hong, Liu

    2013-08-01

    During the application of the mass-action-equation models to the study of amyloid fiber formation, time-consuming numerical calculations constitute a major bottleneck. To conquer this difficulty, here an alternative efficient method is introduced for the fragmentation-only model. It includes two basic steps: (1) simulate close-formed time-evolutionary equations for the number concentration P(t) derived from the moment-closure method; (2) reconstruct the detailed fiber length distribution based on the knowledge of moments obtained in the first step. Compared to direct calculation, our method speeds up the performance by at least 10 000 times (from days to seconds). The accuracy is also satisfactory if suitable functions for the approximate fibril length distribution are taken. Further application to the sonication studies on PI264-b-PFS48 micelles performed by Guerin et al. confirms our method is very promising for the real-time analysis of the experiments on fibril fragmentation.

  13. Real-time structured light depth extraction

    NASA Astrophysics Data System (ADS)

    Keller, Kurtis; Ackerman, Jeremy D.

    2000-03-01

    Gathering depth data using structured light has been a procedure for many different environments and uses. Many of these system are utilized instead of laser line scanning because of their quickness. However, to utilize depth extraction for some applications, in our case laparoscopic surgery, the depth extraction must be in real time. We have developed an apparatus that speeds up the raw image display and grabbing in structured light depth extraction from 30 frames per second to 60 and 180 frames per second. This results in an updated depth and texture map of about 15 times per second versus about 3. This increased update rate allows for real time depth extraction for use in augmented medical/surgical applications. Our miniature, fist-sized projector utilizes an internal ferro-reflective LCD display that is illuminated with cold light from a flex light pipe. The miniature projector, attachable to a laparoscope, displays inverted pairs of structured light into the body where these images are then viewed by a high-speed camera set slightly off axis from the projector that grabs images synchronously. The images from the camera are ported to a graphics-processing card where six frames are worked on simultaneously to extract depth and create mapped textures from these images. This information is then sent to the host computer with 3D coordinate information of the projector/camera and the associated textures. The surgeon is then able to view body images in real time from different locations without physically moving the laparoscope imager/projector, thereby, reducing the trauma of moving laparoscopes in the patient.

  14. Real-time computed optical interferometric tomography

    NASA Astrophysics Data System (ADS)

    Shemonski, Nathan D.; Liu, Yuan-Zhi; Ahmad, Adeel; Adie, Steven G.; Carney, P. Scott; Boppart, Stephen A.

    2014-03-01

    High-resolution tomography is of great importance to many areas of biomedical imaging, but with it comes several apparent tradeoffs such as a narrowing depth-of-field and increasing optical aberrations. Overcoming these challenges has attracted many hardware and computational solutions. Hardware solutions, though, can become bulky or expensive and computational approaches can require high computing power or large processing times. This study demonstrates memory efficient implementations of interferometric synthetic aperture microscopy (ISAM) and computational adaptive optics (CAO) - two computational approaches for overcoming the depthof- field limitation and the effect of optical aberrations in optical coherence tomography (OCT). Traditionally requiring lengthy post processing, here we report implementations of ISAM and CAO on a single GPU for real-time in vivo imaging. Real-time, camera-limited ISAM processing enabled reliable acquisition of stable data for in vivo imaging, and CAO processing on the same GPU is shown to quickly correct static aberrations. These algorithmic advances hold the promise for high-resolution volumetric imaging in time-sensitive situations as well as enabling aberrationfree cellular-level volumetric tomography.

  15. Real-Time Flight Envelope Monitoring System

    NASA Technical Reports Server (NTRS)

    Kerho, Michael; Bragg, Michael B.; Ansell, Phillip J.

    2012-01-01

    The objective of this effort was to show that real-time aircraft control-surface hinge-moment information could be used to provide a robust and reliable prediction of vehicle performance and control authority degradation. For a given airfoil section with a control surface -- be it a wing with an aileron, rudder, or elevator -- the control-surface hinge moment is sensitive to the aerodynamic characteristics of the section. As a result, changes in the aerodynamics of the section due to angle-of-attack or environmental effects such as icing, heavy rain, surface contaminants, bird strikes, or battle damage will affect the control surface hinge moment. These changes include both the magnitude of the hinge moment and its sign in a time-averaged sense, and the variation of the hinge moment with time. The current program attempts to take the real-time hinge moment information from the aircraft control surfaces and develop a system to predict aircraft envelope boundaries across a range of conditions, alerting the flight crew to reductions in aircraft controllability and flight boundaries.

  16. Real-time design with peer tasks

    NASA Technical Reports Server (NTRS)

    Goforth, Andre; Howes, Norman R.; Wood, Jonathan D.; Barnes, Michael J.

    1995-01-01

    We introduce a real-time design methodology for large scale, distributed, parallel architecture, real-time systems (LDPARTS), as an alternative to those methods using rate or dead-line monotonic analysis. In our method the fundamental units of prioritization, work items, are domain specific objects with timing requirements (deadlines) found in user's specification. A work item consists of a collection of tasks of equal priority. Current scheduling theories are applied with artifact deadlines introduced by the designer whereas our method schedules work items to meet user's specification deadlines (sometimes called end-to-end deadlines). Our method supports these scheduling properties. Work item scheduling is based on domain specific importance instead of task level urgency and still meets as many user specification deadlines as can be met by scheduling tasks with respect to urgency. Second, the minimum (closest) on-line deadline that can be guaranteed for a work item of highest importance, scheduled at run time, is approximately the inverse of the throughput, measured in work items per second. Third, throughput is not degraded during overload and instead of resorting to task shedding during overload, the designer can specify which work items to shed. We prove these properties in a mathematical model.

  17. Fast underdetermined BSS architecture design methodology for real time applications.

    PubMed

    Mopuri, Suresh; Reddy, P Sreenivasa; Acharyya, Amit; Naik, Ganesh R

    2015-01-01

    In this paper, we propose a high speed architecture design methodology for the Under-determined Blind Source Separation (UBSS) algorithm using our recently proposed high speed Discrete Hilbert Transform (DHT) targeting real time applications. In UBSS algorithm, unlike the typical BSS, the number of sensors are less than the number of the sources, which is of more interest in the real time applications. The DHT architecture has been implemented based on sub matrix multiplication method to compute M point DHT, which uses N point architecture recursively and where M is an integer multiples of N. The DHT architecture and state of the art architecture are coded in VHDL for 16 bit word length and ASIC implementation is carried out using UMC 90 - nm technology @V DD = 1V and @ 1MHZ clock frequency. The proposed architecture implementation and experimental comparison results show that the DHT design is two times faster than state of the art architecture. PMID:26737514

  18. Prototype COBRA near-real-time processor

    NASA Astrophysics Data System (ADS)

    Earp, Samuel L.; Marshall, J. W.; Anthony, E. R.

    1996-05-01

    The U.S. Marine Corps COBRA countermine surveillance program has developed, as a risk- reduction alternative, a near real-time processor for the output of the COBRA multispectral camera. This processor has been tested using approximately 13.5 hours of video data from the COBRA DT-0 developmental test, representing approximately 243,000 frames of multispectral data. The results have been very encouraging--the system is robust and the minefield detection performance has met the goals of the COBRA program. The MITRE COBRA prototype processor is built from commercial-off-the-shelf VME bus technology. Video capture is provided by a Transtech TDM 435 capture/display VME card. Control is performed on a GMSV64 Super Sparc card that resides in two VME slots. The compute engine consists of two Pentek 4270 Quad TMS320C40 digital signal processing boards. There are two additional 6U VME boards to provide fast SCSI IO. The system is capable of capturing, digitizing and processing the COBRA data stream at between one-eighth and one-half real-time, depending on processing options. The nominal compute power of the system is 2.2 GOPS, 450 MFLOPS. The system is easily upgradeable due to the open architecture--one proposed upgrade will be to increase the number of available TMS320C40 processors to sixteen, providing real-time performance without compromising the current investment in software and hardware. The software for the system is primarily written in C, with hand-optimized assembler code for portions of the compute kernel. The algorithm that is implemented is based on the MITRE minefield detection algorithm detailed at AeroSense '95. The system development required a registration algorithm--this was the only algorithm development that was performed, the rest of the algorithms coming from previous MITRE effort on the COBRA program. Lessons learned from the development and upgrade/test plans will be presented.

  19. Waste collection multi objective model with real time traceability data.

    PubMed

    Faccio, Maurizio; Persona, Alessandro; Zanin, Giorgia

    2011-12-01

    Waste collection is a highly visible municipal service that involves large expenditures and difficult operational problems, plus it is expensive to operate in terms of investment costs (i.e. vehicles fleet), operational costs (i.e. fuel, maintenances) and environmental costs (i.e. emissions, noise and traffic congestions). Modern traceability devices, like volumetric sensors, identification RFID (Radio Frequency Identification) systems, GPRS (General Packet Radio Service) and GPS (Global Positioning System) technology, permit to obtain data in real time, which is fundamental to implement an efficient and innovative waste collection routing model. The basic idea is that knowing the real time data of each vehicle and the real time replenishment level at each bin makes it possible to decide, in function of the waste generation pattern, what bin should be emptied and what should not, optimizing different aspects like the total covered distance, the necessary number of vehicles and the environmental impact. This paper describes a framework about the traceability technology available in the optimization of solid waste collection, and introduces an innovative vehicle routing model integrated with the real time traceability data, starting the application in an Italian city of about 100,000 inhabitants. The model is tested and validated using simulation and an economical feasibility study is reported at the end of the paper. PMID:21821406

  20. Near real-time traffic routing

    NASA Technical Reports Server (NTRS)

    Yang, Chaowei (Inventor); Cao, Ying (Inventor); Xie, Jibo (Inventor); Zhou, Bin (Inventor)

    2012-01-01

    A near real-time physical transportation network routing system comprising: a traffic simulation computing grid and a dynamic traffic routing service computing grid. The traffic simulator produces traffic network travel time predictions for a physical transportation network using a traffic simulation model and common input data. The physical transportation network is divided into a multiple sections. Each section has a primary zone and a buffer zone. The traffic simulation computing grid includes multiple of traffic simulation computing nodes. The common input data includes static network characteristics, an origin-destination data table, dynamic traffic information data and historical traffic data. The dynamic traffic routing service computing grid includes multiple dynamic traffic routing computing nodes and generates traffic route(s) using the traffic network travel time predictions.

  1. A Flexible Real-Time Architecture

    SciTech Connect

    WICKSTROM,GREGORY L.

    2000-08-17

    Assuring hard real-time characteristics of I/O associated with embedded software is often a difficult task. Input-Output related statements are often intermixed with the computational code, resulting in I/O timing that is dependent on the execution path and computational load. One way to mitigate this problem is through the use of interrupts. However, the non-determinism that is introduced by interrupt driven I/O may be so difficult to analyze that it is prohibited in some high consequence systems. This paper describes a balanced hardware/software solution to obtain consistent interrupt-free I/O timing, and results in software that is much more amenable to analysis.

  2. Real-time applications of neural nets

    SciTech Connect

    Spencer, J.E. )

    1989-10-01

    Producing, accelerating and colliding very high power, low emittance beams for long periods is a formidable problem in real-time control. As energy has grown exponentially in time so has the complexity of the machines and their control systems. Similar growth rates have occurred in many areas e.g. improved integrated circuits have been paid for with comparable increases in complexity. However, in this case, reliability, capability and cost have improved due to reduced size, high production and increased integration which allow various kinds of feedback. In contrast, most large complex systems (LCS) are perceived to lack such possibilities because only one copy is made. Neural nets, as a metaphor for LCS, suggest ways to circumvent such limitations. It is argued that they are logically equivalent to multi-loop feedback/forward control of faulty systems. While complimentary to AI, they mesh nicely with characteristics desired for real-time systems. In this paper, such issues are considered, examples given and possibilities discussed.

  3. Real-time applications of neural nets

    SciTech Connect

    Spencer, J.E.

    1989-05-01

    Producing, accelerating and colliding very high power, low emittance beams for long periods is a formidable problem in real-time control. As energy has grown exponentially in time so has the complexity of the machines and their control systems. Similar growth rates have occurred in many areas, e.g., improved integrated circuits have been paid for with comparable increases in complexity. However, in this case, reliability, capability and cost have improved due to reduced size, high production and increased integration which allow various kinds of feedback. In contrast, most large complex systems (LCS) are perceived to lack such possibilities because only one copy is made. Neural nets, as a metaphor for LCS, suggest ways to circumvent such limitations. It is argued that they are logically equivalent to multi-loop feedback/forward control of faulty systems. While complimentary to AI, they mesh nicely with characteristics desired for real-time systems. Such issues are considered, examples given and possibilities discussed. 21 refs., 6 figs.

  4. Real-time PCR in microfluidic devices

    NASA Astrophysics Data System (ADS)

    Becker, Holger; Hlawatsch, Nadine; Klemm, Richard; Moche, Christian; Hansen-Hagge, Thomas; Gärtner, Claudia

    2014-03-01

    A central method in a standard biochemical laboratory is represented by the polymerase chain reaction (PCR), therefore many attempts have been performed so far to implement this technique in lab-on-a-chip (LOC) devices. PCR is an ideal candidate for miniaturization because of a reduction of assay time and decreased costs for expensive bio-chemicals. In case of the "classical" PCR, detection is done by identification of DNA fragments electrophoretically separated in agarose gels. This method is meanwhile frequently replaced by the so-called Real-Time-PCR because here the exponential increase of amplificates can be observed directly by measurement of DNA interacting fluorescent dyes. Two main methods for on-chip PCRs are available: traditional "batch" PCR in chambers on a chip using thermal cycling, requiring about 30 minutes for a typical PCR protocol and continuous-flow PCR, where the liquid is guided over stationary temperature zones. In the latter case, the PCR protocol can be as fast as 5 minutes. In the presented work, a proof of concept is demonstrated for a real-time-detection of PCR products in microfluidic systems.

  5. Teaching with Real-Time Seismic Data

    NASA Astrophysics Data System (ADS)

    Baldwin, T. K.; Ortiz, A.; Hall-Wallace, M.; Taber, J.; Braile, L.

    2002-12-01

    Many terabytes of digital seismic data have been gathered in the past decade. These data include summary tables of events as well as raw seismograms. The event information, which can be plotted, analyzed statistically and interpreted in the context of plate tectonics and geologic hazards, make excellent classroom investigations. However, the bulk of the data are raw seismograms that require advanced knowledge and specific software to analyze and manipulate thus, they are generally inaccessible to a non-seismologist. To make real-time seismic data more accessible to students in high schools and colleges, we are developing a network of school seismometers through the IRIS Seismometer in Schools Program. The goal of this program is to promote seismology as a platform for teaching principles of physics and Earth science in schools across the nation. When studying plate tectonics and earthquakes, a seismometer in the classroom promotes awareness of earthquake activity around the world and provides an opportunity to teach with real-time data and real-world examples. The AS-1 seismometer is a low cost, durable, yet precise instrument that allows students to both investigate how a seismometer works and the recordings of the instrument, making it ideal for student and classroom use. The AS-1 recording and analysis software, AmaSeis, is simple to use yet includes all the basic tools needed for analysis: waveform display, filtering, and phase picking. The software also includes travel time curves to determine event distance and location. The seismometer keeps time using the computer's clock, which can be updated regularly through the Internet. While each instrument's response is unique, it is possible to calibrate the instrument and determine accurate magnitudes for events. In the past year our efforts have resulted in teachers using the seismometer effectively in high school classrooms. For example, using data from their own station and several others, students located

  6. Real-time failure control (SAFD)

    NASA Technical Reports Server (NTRS)

    Panossian, Hagop V.; Kemp, Victoria R.; Eckerling, Sherry J.

    1990-01-01

    The Real Time Failure Control program involves development of a failure detection algorithm, referred as System for Failure and Anomaly Detection (SAFD), for the Space Shuttle Main Engine (SSME). This failure detection approach is signal-based and it entails monitoring SSME measurement signals based on predetermined and computed mean values and standard deviations. Twenty four engine measurements are included in the algorithm and provisions are made to add more parameters if needed. Six major sections of research are presented: (1) SAFD algorithm development; (2) SAFD simulations; (3) Digital Transient Model failure simulation; (4) closed-loop simulation; (5) SAFD current limitations; and (6) enhancements planned for.

  7. Near real time data processing system

    NASA Astrophysics Data System (ADS)

    Mousessian, Ardvas; Vuu, Christina

    2008-08-01

    Raytheon recently developed and implemented a Near Real Time (NRT) data processing subsystem for Earth Observing System (EOS) Microwave Limb Sounder (MLS3) instrument on NASA Aura spacecraft. The NRT can be viewed as a customized Science Information Processing System (SIPS) where the measurements and information provided by the instrument are expeditiously processed, packaged, and delivered. The purpose of the MLS NRT is to process Level 0 data up through Level 2, and distribute standard data products to the customer within 3-5 hours of the first set of data arrival.

  8. Real-Time Surface Traffic Adviser

    NASA Technical Reports Server (NTRS)

    Glass, Brian J. (Inventor); Spirkovska, Liljana (Inventor); McDermott, William J. (Inventor); Reisman, Ronald J. (Inventor); Gibson, James (Inventor); Iverson, David L. (Inventor)

    2001-01-01

    A real-time data management system which uses data generated at different rates by multiple heterogeneous incompatible data sources are presented. In one embodiment, the invention is as an airport surface traffic data management system (traffic adviser) that electronically interconnects air traffic control, airline, and airport operations user communities to facilitate information sharing and improve taxi queuing. The system uses an expert system to fuse dam from a variety of airline, airport operations, ramp control, and air traffic control sources, in order to establish, predict, and update reference data values for every aircraft surface operation.

  9. Real-time teleteaching in medical physics.

    PubMed

    Woo, M; Ng, Kh

    2008-01-01

    Medical physics is a relatively small professional community, usually with a scarcity of expertise that could greatly benefit students entering the field. However, the reach of the profession can span great geographical distances, making the training of students a difficult task. In addition to the requirement of training new students, the evolving field of medical physics, with its many emerging advanced techniques and technologies, could benefit greatly from ongoing continuing education as well as consultation with experts.Many continuing education courses and workshops are constantly being offered, including many web-based study courses and virtual libraries. However, one mode of education and communication that has not been widely used is the real-time interactive process. Video-based conferencing systems do exist, but these usually require a substantial amount of effort and cost to set up.The authors have been working on promoting the ever-expanding capability of the Internet to facilitate the education of medical physics to students entering the field. A pilot project has been carried out for six years and reported previously. The project is a collaboration between the Department of Medical Physics at the Toronto Odette Cancer Centre in Canada and the Department of Biomedical Imaging at the University of Malaya in Malaysia. Since 2001, medical physics graduate students at the University of Malaya have been taught by lecturers from Toronto every year, using the Internet as the main tool of communication.The pilot study explored the different methods that can be used to provide real-time interactive remote education, and delivered traditional classroom lectures as well as hands-on workshops.Another similar project was started in 2007 to offer real-time teaching to a class of medical physics students at Wuhan University in Hubei, China. There are new challenges as well as new opportunities associated with this project. By building an inventory of tools and

  10. A novel compact real time radiation detector.

    PubMed

    Li, Shiping; Xu, Xiufeng; Cao, Hongrui; Tang, Shibiao; Ding, Baogang; Yin, Zejie

    2012-08-01

    A novel compact real time radiation detector with cost-effective, ultralow power and high sensitivity based on Geiger counter is presented. The power consumption of this detector which employs CMOS electro circuit and ultralow-power microcontroller is down to only 12.8 mW. It can identify the presences of 0.22 μCi (60)Co at a distance of 1.29 m. Furthermore, the detector supports both USB bus and serial interface. It can be used for personal radiation monitoring and also fits the distributed sensor network for radiation detection. PMID:22738843

  11. Real Time Telemetry Data Capture and Storage

    SciTech Connect

    DeAguero, James G.

    1997-05-14

    This program is used to capture telemetry data from remote instrumentation systems. The data can be captured at the rate of 1M bit per second. The data can come in one of several formats, NRZ, RZ, and Bi-Phase. The DECOM software takes the serial data stream and locks on to a unique code word. By tracking the code word the software can strip out the information. Thus the program can display the incoming data real time while saving the data to disk.

  12. Simultaneous real-time data collection methods

    NASA Technical Reports Server (NTRS)

    Klincsek, Thomas

    1992-01-01

    This paper describes the development of electronic test equipment which executes, supervises, and reports on various tests. This validation process uses computers to analyze test results and report conclusions. The test equipment consists of an electronics component and the data collection and reporting unit. The PC software, display screens, and real-time data-base are described. Pass-fail procedures and data replay are discussed. The OS2 operating system and Presentation Manager user interface system were used to create a highly interactive automated system. The system outputs are hardcopy printouts and MS DOS format files which may be used as input for other PC programs.

  13. Real-time radar rainfall estimation

    NASA Astrophysics Data System (ADS)

    Anagnostou, Emmanouil Nikolaos

    1997-08-01

    This research reports on several aspects of real-time monitoring of the spatial and temporal distribution of rainfall from ground-based weather radar. Optimization of the performance of the National Weather Service's Precipitation Processing Subsystem (PPS) is the first objective. This is achieved by developing a calibration procedure which simultaneously estimates the optimal parameter values by providing a global assessment of the system's performance. Evaluation of the system is based on a data set consisting of two months of radar reflectivity measurements, and hourly raingage rainfall accumulations, from the Melbourne, Florida WSR-88D site. Radar-raingage root mean square (RMS) difference reduction up to 20% with respect to the default system parameter values is demonstrated. Investigation of statistical procedures for real-time adjustment of the mean-field systematic radar rainfall error is the second objective. For this purpose, a data- based Monte Carlo simulation experiment is performed. The study uses an extensive data set of hourly radar rainfall products and raingage accumulations from the Tulsa, Oklahoma WSR-88D site. This intercomparison study concluded to a bias procedure which overall appeared to perform better than the other. The main results from this research are: (1) statistical methods with optimal error model parameters perform significantly better than using only bias observations, and (2) bias adjustment is mostly effective in cold season precipitation measurements. Final objective of this research is development of a new real-time radar rainfall estimation algorithm. The new processing steps introduced in this algorithm are beam- height effect correction, vertical integration, rain classification, and continuous range effect correction. Additionally, the algorithm applies advection correction at the gridded rainfall rates to minimize the temporal sampling effect, and its calibration is cast in a recursive formulation with parameters

  14. Real-Time Reed-Solomon Decoder

    NASA Technical Reports Server (NTRS)

    Maki, Gary K.; Cameron, Kelly B.; Owsley, Patrick A.

    1994-01-01

    Generic Reed-Solomon decoder fast enough to correct errors in real time in practical applications designed to be implemented in fewer and smaller very-large-scale integrated, VLSI, circuit chips. Configured to operate in pipelined manner. One outstanding aspect of decoder design is that Euclid multiplier and divider modules contain Galoisfield multipliers configured as combinational-logic cells. Operates at speeds greater than older multipliers. Cellular configuration highly regular and requires little interconnection area, making it ideal for implementation in extraordinarily dense VLSI circuitry. Flight electronics single chip version of this technology implemented and available.

  15. Systems Analyze Water Quality in Real Time

    NASA Technical Reports Server (NTRS)

    2010-01-01

    A water analyzer developed under Small Business Innovation Research (SBIR) contracts with Kennedy Space Center now monitors treatment processes at water and wastewater facilities around the world. Originally designed to provide real-time detection of nutrient levels in hydroponic solutions for growing plants in space, the ChemScan analyzer, produced by ASA Analytics Inc., of Waukesha, Wisconsin, utilizes spectrometry and chemometric algorithms to automatically analyze multiple parameters in the water treatment process with little need for maintenance, calibration, or operator intervention. The company has experienced a compound annual growth rate of 40 percent over its 15-year history as a direct result of the technology's success.

  16. Real-Time Calibration of the Murchison Widefield Array

    NASA Astrophysics Data System (ADS)

    Mitchell, D. A.; Greenhill, L. J.; Wayth, R. B.; Sault, R. J.; Lonsdale, C. J.; Cappallo, R. J.; Morales, M. F.; Ord, S. M.

    2008-11-01

    The interferometric technique known as peeling addresses many of the challenges faced when observing with low-frequency radio arrays, and is a promising tool for the associated calibration systems. We investigate a real-time peeling implementation for next-generation radio interferometers such as the Murchison widefield array (MWA). The MWA is being built in Australia and will observe the radio sky between 80 and 300 MHz. The data rate produced by the correlator is just over 19 GB/s (a few peta-bytes/day). It is impractical to store data generated at this rate, and software is currently being developed to calibrate and form images in real time. The software will run on-site on a high-throughput real-time computing cluster at several tera-flops, and a complete cycle of calibration and imaging will be completed every 8 s. Various properties of the implementation are investigated using simulated data. The algorithm is seen to work in the presence of strong galactic emission and with various ionospheric conditions. It is also shown to scale well as the number of antennas increases, which is essential for many upcoming instruments. Lessons from MWA pipeline development and processing of simulated data may be applied to future low-frequency fixed dipole arrays.

  17. Real-time fractal signal processing in the time domain

    NASA Astrophysics Data System (ADS)

    Hartmann, András; Mukli, Péter; Nagy, Zoltán; Kocsis, László; Hermán, Péter; Eke, András

    2013-01-01

    Fractal analysis has proven useful for the quantitative characterization of complex time series by scale-free statistical measures in various applications. The analysis has commonly been done offline with the signal being resident in memory in full length, and the processing carried out in several distinct passes. However, in many relevant applications, such as monitoring or forecasting, algorithms are needed to capture changes in the fractal measure real-time. Here we introduce real-time variants of the Detrended Fluctuation Analysis (DFA) and the closely related Signal Summation Conversion (SSC) methods, which are suitable to estimate the fractal exponent in one pass. Compared to offline algorithms, the precision is the same, the memory requirement is significantly lower, and the execution time depends on the same factors but with different rates. Our tests show that dynamic changes in the fractal parameter can be efficiently detected. We demonstrate the applicability of our real-time methods on signals of cerebral hemodynamics acquired during open-heart surgery.

  18. Dynamic Bayesian filtering for real-time seismic analyses

    SciTech Connect

    Blough, D.K.; Rohay, A.C.; Anderson, K.K.; Nicholson, W.L.

    1994-04-01

    State space modeling, which includes techniques such as the Kalman filter, has been used to analyze many non-stationary time series. The ability of these dynamic models to adapt and track changes in the underlying process makes them attractive for application to the real-time analysis of three-component seismic waveforms. The authors are investigating the application of state space models formulated as Bayesian time series models to phase detection, polarization, and spectrogram estimation of seismograms. This approach removes the need to specify data windows in the time series for time averaging estimation (e.g., spectrum estimation). They are using this model to isolate particular seismic phases based on polarization parameters that are determined at a spectrum of frequencies. They plan to use polarization parameters, frequency spectra, and magnitudes to discriminate between different types of seismic sources. They present the application of this technique to artificial time series and to several real seismic events including the Non-Proliferation Experiment (NPE) two nuclear tests and three earthquakes from the Nevada Test site, as recorded on several regional broadband seismic stations. A preliminary result of this analysis indicates that earthquakes and explosions can potentially be discriminated on the bass of the polarization characteristics of scattered seismic phases. However, the chemical (NPE) and nuclear explosions appear to have very similar polarization characteristics.

  19. Terrestrial Real-Time Volcano Monitoring

    NASA Astrophysics Data System (ADS)

    Franke, M.

    2013-12-01

    As volcano monitoring involves more and different sensors from seismic to GPS receivers, from video and thermal cameras to multi-parameter probes measuring temperature, ph values and humidity in the ground and the air, it becomes important to design real-time networks that integrate and leverage the multitude of available parameters. In order to do so some simple principles need to be observed: a) a common time base for all measurements, b) a packetized general data communication protocol for acquisition and distribution, c) an open and well documented interface to the data permitting standard and emerging innovative processing, and d) an intuitive visualization platform for scientists and civil defense personnel. Although mentioned as simple principles, the list above does not necessarily lead to obvious solutions or integrated systems, which is, however, required to take advantage of the available data. Only once the different data streams are put into context to each other in terms of time and location can a broader view be obtained and additional information extracted. The presentation is a summary of currently available technologies and how they can achieve the goal of an integrated real-time volcano monitoring system. A common time base are standard for seismic and GPS networks. In different projects we extended this to video feeds and time-lapse photography. Other probes have been integrated with vault interface enclosures (VIE) as used in the Transportable Array (TA) of the USArray. The VIE can accommodate the sensors employed in volcano monitoring. The TA has shown that Antelope is a versatile and robust middleware. It provides the required packetized general communication protocol that is independent from the actual physical communication link leaving the network design to adopt appropriate and possible hybrid solutions. This applies for the data acquisition and the data/information dissemination providing both a much needed collaboration platform, as

  20. Residential Real-time Price Response Simulation

    SciTech Connect

    Widergren, Steven E.; Subbarao, Krishnappa; Chassin, David P.; Fuller, Jason C.; Pratt, Robert G.

    2011-10-10

    The electric industry is gaining experience with innovative price responsive demand pilots and limited roll-outs to customers. One of these pilots is investigating real-time pricing signals to engage end-use systems and local distributed generation and storage in a distributed optimization process. Attractive aspects about the approach include strong scalability characteristics, simplified interfaces between automation devices, and the adaptability to integrate a wide variety of devices and systems. Experience in this nascent field is revealing a rich array of for engineering decisions and the application of complexity theory. To test the decisions, computer simulations are used to reveal insights about design, demand elasticity, and the limits of response (including consumer fatigue). Agent-based approaches lend themselves well in the simulation to modeling the participation and interaction of each piece of equipment on a distribution feeder. This paper discusses rate design and simulation experiences at the distribution feeder level where consumers and their HVAC systems and water heaters on a feeder receive real-time pricing signals.

  1. NSTX power supply real time controller

    SciTech Connect

    Neumeyer, C.; Hatcher, R.; Marsala, R.; Ramakrishnan, S.

    2000-01-06

    The NSTX is a new national facility for the study of plasma confinement, heating, and current drive in a low aspect ratio, spherical torus (ST) configuration. The ST configuration is an alternate magnetic confinement concept which is characterized by high beta (ratio plasma pressure to magnetic field pressure) and low toroidal field compared to conventional tokamaks, and could provide a pathway to the realization of a practical fusion power source. The NSTX depends on a real time, high speed, synchronous, and deterministic control system acting on a system of thyristor rectifier power supplies to (1) establish the initial magnetic field configuration; (2) initiate plasma within the vacuum vessel; (3) inductively drive plasma current; and (4) control plasma position and shape. For the initial ``day 0'' 1st plasma operations (Feb. 1999), the system was limited to closed loop proportional-integral current control of the power supplies based on preprogrammed reference waveforms. For the ``day 1'' phase of operations beginning Sept. 1999 the loop has been closed on plasma current and position. This paper focuses on the Power Supply Real Time Controller (PSRTC).

  2. Real-time adaptive video image enhancement

    NASA Astrophysics Data System (ADS)

    Garside, John R.; Harrison, Chris G.

    1999-07-01

    As part of a continuing collaboration between the University of Manchester and British Aerospace, a signal processing array has been constructed to demonstrate that it is feasible to compensate a video signal for the degradation caused by atmospheric haze in real-time. Previously reported work has shown good agreement between a simple physical model of light scattering by atmospheric haze and the observed loss of contrast. This model predicts a characteristic relationship between contrast loss in the image and the range from the camera to the scene. For an airborne camera, the slant-range to a point on the ground may be estimated from the airplane's pose, as reported by the inertial navigation system, and the contrast may be obtained from the camera's output. Fusing data from these two streams provides a means of estimating model parameters such as the visibility and the overall illumination of the scene. This knowledge allows the same model to be applied in reverse, thus restoring the contrast lost to atmospheric haze. An efficient approximation of range is vital for a real-time implementation of the method. Preliminary results show that an adaptive approach to fitting the model's parameters, exploiting the temporal correlation between video frames, leads to a robust implementation with a significantly accelerated throughput.

  3. Real-time computerized annotation of pictures.

    PubMed

    Li, Jia; Wang, James Z

    2008-06-01

    Developing effective methods for automated annotation of digital pictures continues to challenge computer scientists. The capability of annotating pictures by computers can lead to breakthroughs in a wide range of applications, including Web image search, online picture-sharing communities, and scientific experiments. In this work, the authors developed new optimization and estimation techniques to address two fundamental problems in machine learning. These new techniques serve as the basis for the Automatic Linguistic Indexing of Pictures - Real Time (ALIPR) system of fully automatic and high speed annotation for online pictures. In particular, the D2-clustering method, in the same spirit as k-means for vectors, is developed to group objects represented by bags of weighted vectors. Moreover, a generalized mixture modeling technique (kernel smoothing as a special case) for non-vector data is developed using the novel concept of Hypothetical Local Mapping (HLM). ALIPR has been tested by thousands of pictures from an Internet photo-sharing site, unrelated to the source of those pictures used in the training process. Its performance has also been studied at an online demo site where arbitrary users provide pictures of their choices and indicate the correctness of each annotation word. The experimental results show that a single computer processor can suggest annotation terms in real-time and with good accuracy. PMID:18421105

  4. Real-time sensor data validation

    NASA Technical Reports Server (NTRS)

    Bickmore, Timothy W.

    1994-01-01

    This report describes the status of an on-going effort to develop software capable of detecting sensor failures on rocket engines in real time. This software could be used in a rocket engine controller to prevent the erroneous shutdown of an engine due to sensor failures which would otherwise be interpreted as engine failures by the control software. The approach taken combines analytical redundancy with Bayesian belief networks to provide a solution which has well defined real-time characteristics and well-defined error rates. Analytical redundancy is a technique in which a sensor's value is predicted by using values from other sensors and known or empirically derived mathematical relations. A set of sensors and a set of relations among them form a network of cross-checks which can be used to periodically validate all of the sensors in the network. Bayesian belief networks provide a method of determining if each of the sensors in the network is valid, given the results of the cross-checks. This approach has been successfully demonstrated on the Technology Test Bed Engine at the NASA Marshall Space Flight Center. Current efforts are focused on extending the system to provide a validation capability for 100 sensors on the Space Shuttle Main Engine.

  5. 3D MR imaging in real time

    NASA Astrophysics Data System (ADS)

    Guttman, Michael A.; McVeigh, Elliot R.

    2001-05-01

    A system has been developed to produce live 3D volume renderings from an MR scanner. Whereas real-time 2D MR imaging has been demonstrated by several groups, 3D volumes are currently rendered off-line to gain greater understanding of anatomical structures. For example, surgical planning is sometimes performed by viewing 2D images or 3D renderings from previously acquired image data. A disadvantage of this approach is misregistration which could occur if the anatomy changes due to normal muscle contractions or surgical manipulation. The ability to produce volume renderings in real-time and present them in the magnet room could eliminate this problem, and enable or benefit other types of interventional procedures. The system uses the data stream generated by a fast 2D multi- slice pulse sequence to update a volume rendering immediately after a new slice is available. We demonstrate some basic types of user interaction with the rendering during imaging at a rate of up to 20 frames per second.

  6. Real-Time and Near Real-Time Data for Space Weather Applications and Services

    NASA Astrophysics Data System (ADS)

    Singer, H. J.; Balch, C. C.; Biesecker, D. A.; Matsuo, T.; Onsager, T. G.

    2015-12-01

    Space weather can be defined as conditions in the vicinity of Earth and in the interplanetary environment that are caused primarily by solar processes and influenced by conditions on Earth and its atmosphere. Examples of space weather are the conditions that result from geomagnetic storms, solar particle events, and bursts of intense solar flare radiation. These conditions can have impacts on modern-day technologies such as GPS or electric power grids and on human activities such as astronauts living on the International Space Station or explorers traveling to the moon or Mars. While the ultimate space weather goal is accurate prediction of future space weather conditions, for many applications and services, we rely on real-time and near-real time observations and model results for the specification of current conditions. In this presentation, we will describe the space weather system and the need for real-time and near-real time data that drive the system, characterize conditions in the space environment, and are used by models for assimilation and validation. Currently available data will be assessed and a vision for future needs will be given. The challenges for establishing real-time data requirements, as well as acquiring, processing, and disseminating the data will be described, including national and international collaborations. In addition to describing how the data are used for official government products, we will also give examples of how these data are used by both the public and private sector for new applications that serve the public.

  7. Real-time multiplexed digital cavity-enhanced spectroscopy.

    PubMed

    Boyson, Toby K; Dagdigian, Paul J; Pavey, Karl D; FitzGerald, Nicholas J; Spence, Thomas G; Moore, David S; Harb, Charles C

    2015-10-01

    Cavity-enhanced spectroscopy is a sensitive optical absorption technique but one where the practical applications have been limited to studying small wavelength ranges. This Letter shows that wideband operation can be achieved by combining techniques usually reserved for the communications community with that of cavity-enhanced spectroscopy, producing a multiplexed real-time cavity-enhanced spectrometer. We use multiple collinear laser sources operating asynchronously and simultaneously while being detected on a single photodetector. This is synonymous with radio frequency (RF) cellular systems in which signals are detected on a single antenna but decoded uniquely. Here, we demonstrate results with spectra of methyl salicylate and show parts-per-billion per root hertz sensitivity measured in real-time. PMID:26421581

  8. Real-time multiplexed digital cavity-enhanced spectroscopy

    DOE PAGESBeta

    Boyson, Toby K.; Dagdigian, Paul J.; Pavey, Karl D.; Fitzgerald, Nicholas J.; Spence, Thomas G.; Moore, David S.; Harb, Charles C.

    2015-10-01

    Cavity-enhanced spectroscopy is a sensitive optical absorption technique but one where the practical applications have been limited to studying small wavelength ranges. In addition, this Letter shows that wideband operation can be achieved by combining techniques usually reserved for the communications community with that of cavity-enhanced spectroscopy, producing a multiplexed real-time cavity-enhanced spectrometer. We use multiple collinear laser sources operating asynchronously and simultaneously while being detected on a single photodetector. This is synonymous with radio frequency (RF) cellular systems in which signals are detected on a single antenna but decoded uniquely. Here, we demonstrate results with spectra of methyl salicylatemore » and show parts-per-billion per root hertz sensitivity measured in real-time.« less

  9. Real-time multiplexed digital cavity-enhanced spectroscopy

    SciTech Connect

    Boyson, Toby K.; Dagdigian, Paul J.; Pavey, Karl D.; Fitzgerald, Nicholas J.; Spence, Thomas G.; Moore, David S.; Harb, Charles C.

    2015-10-01

    Cavity-enhanced spectroscopy is a sensitive optical absorption technique but one where the practical applications have been limited to studying small wavelength ranges. In addition, this Letter shows that wideband operation can be achieved by combining techniques usually reserved for the communications community with that of cavity-enhanced spectroscopy, producing a multiplexed real-time cavity-enhanced spectrometer. We use multiple collinear laser sources operating asynchronously and simultaneously while being detected on a single photodetector. This is synonymous with radio frequency (RF) cellular systems in which signals are detected on a single antenna but decoded uniquely. Here, we demonstrate results with spectra of methyl salicylate and show parts-per-billion per root hertz sensitivity measured in real-time.

  10. Identifying financial crises in real time

    NASA Astrophysics Data System (ADS)

    da Fonseca, Eder Lucio; Ferreira, Fernando F.; Muruganandam, Paulsamy; Cerdeira, Hilda A.

    2013-03-01

    Following the thermodynamic formulation of a multifractal measure that was shown to enable the detection of large fluctuations at an early stage, here we propose a new index which permits us to distinguish events like financial crises in real time. We calculate the partition function from which we can obtain thermodynamic quantities analogous to the free energy and specific heat. The index is defined as the normalized energy variation and it can be used to study the behavior of stochastic time series, such as financial market daily data. Famous financial market crashes-Black Thursday (1929), Black Monday (1987) and the subprime crisis (2008)-are identified with clear and robust results. The method is also applied to the market fluctuations of 2011. From these results it appears as if the apparent crisis of 2011 is of a different nature to the other three. We also show that the analysis has forecasting capabilities.

  11. Real-time forecasts of dengue epidemics

    NASA Astrophysics Data System (ADS)

    Yamana, T. K.; Shaman, J. L.

    2015-12-01

    Dengue is a mosquito-borne viral disease prevalent in the tropics and subtropics, with an estimated 2.5 billion people at risk of transmission. In many areas with endemic dengue, disease transmission is seasonal but prone to high inter-annual variability with occasional severe epidemics. Predicting and preparing for periods of higher than average transmission is a significant public health challenge. Here we present a model of dengue transmission and a framework for optimizing model simulations with real-time observational data of dengue cases and environmental variables in order to generate ensemble-based forecasts of the timing and severity of disease outbreaks. The model-inference system is validated using synthetic data and dengue outbreak records. Retrospective forecasts are generated for a number of locations and the accuracy of these forecasts is quantified.

  12. Wi-Fi real time location systems

    NASA Astrophysics Data System (ADS)

    Doll, Benjamin A.

    This thesis objective was to determine the viability of utilizing an untrained Wi-Fi. real time location system as a GPS alternative for indoor environments. Background. research showed that GPS is rarely able to penetrate buildings to provide reliable. location data. The benefit of having location information in a facility and how they might. be used for disaster or emergency relief personnel and their resources motivated this. research. A building was selected with a well-deployed Wi-Fi infrastructure and its. untrained location feature was used to determine the distance between the specified. test points and the system identified location. It was found that the average distance. from the test point throughout the facility was 14.3 feet 80% of the time. This fell within. the defined viable range and supported that an untrained Wi-Fi RTLS system could be a. viable solution for GPS's lack of availability indoors.

  13. Exploding Nitromethane in Silico, in Real Time.

    PubMed

    Fileti, Eudes Eterno; Chaban, Vitaly V; Prezhdo, Oleg V

    2014-10-01

    Nitromethane (NM) is widely applied in chemical technology as a solvent for extraction, cleaning, and chemical synthesis. NM was considered safe for a long time, until a railroad tanker car exploded in 1958. We investigate the detonation kinetics and explosion reaction mechanisms in a variety of systems consisting of NM, molecular oxygen, and water vapor. Reactive molecular dynamics allows us to simulate reactions in time-domain, as they occur in real life. High polarity of the NM molecule is shown to play a key role, driving the first exothermic step of the reaction. Rapid temperature and pressure growth stimulate the subsequent reaction steps. Oxygen is important for faster oxidation, whereas its optimal concentration is in agreement with the proposed reaction mechanism. Addition of water (50 mol %) inhibits detonation; however, water does not prevent detonation entirely. The reported results provide important insights for improving applications of NM and preserving the safety of industrial processes. PMID:26278455

  14. Real Time Monitor of Grid job executions

    NASA Astrophysics Data System (ADS)

    Colling, D. J.; Martyniak, J.; McGough, A. S.; Křenek, A.; Sitera, J.; Mulač, M.; Dvořák, F.

    2010-04-01

    In this paper we describe the architecture and operation of the Real Time Monitor (RTM), developed by the Grid team in the HEP group at Imperial College London. This is arguably the most popular dissemination tool within the EGEE [1] Grid. Having been used, on many occasions including GridFest and LHC inauguration events held at CERN in October 2008. The RTM gathers information from EGEE sites hosting Logging and Bookkeeping (LB) services. Information is cached locally at a dedicated server at Imperial College London and made available for clients to use in near real time. The system consists of three main components: the RTM server, enquirer and an apache Web Server which is queried by clients. The RTM server queries the LB servers at fixed time intervals, collecting job related information and storing this in a local database. Job related data includes not only job state (i.e. Scheduled, Waiting, Running or Done) along with timing information but also other attributes such as Virtual Organization and Computing Element (CE) queue - if known. The job data stored in the RTM database is read by the enquirer every minute and converted to an XML format which is stored on a Web Server. This decouples the RTM server database from the client removing the bottleneck problem caused by many clients simultaneously accessing the database. This information can be visualized through either a 2D or 3D Java based client with live job data either being overlaid on to a 2 dimensional map of the world or rendered in 3 dimensions over a globe map using OpenGL.

  15. Towards real time speckle controlled retinal photocoagulation

    NASA Astrophysics Data System (ADS)

    Bliedtner, Katharina; Seifert, Eric; Stockmann, Leoni; Effe, Lisa; Brinkmann, Ralf

    2016-03-01

    Photocoagulation is a laser treatment widely used for the therapy of several retinal diseases. Intra- and inter-individual variations of the ocular transmission, light scattering and the retinal absorption makes it impossible to achieve a uniform effective exposure and hence a uniform damage throughout the therapy. A real-time monitoring and control of the induced damage is highly requested. Here, an approach to realize a real time optical feedback using dynamic speckle analysis is presented. A 532 nm continuous wave Nd:YAG laser is used for coagulation. During coagulation, speckle dynamics are monitored by a coherent object illumination using a 633nm HeNe laser and analyzed by a CMOS camera with a frame rate up to 1 kHz. It is obvious that a control system needs to determine whether the desired damage is achieved to shut down the system in a fraction of the exposure time. Here we use a fast and simple adaption of the generalized difference algorithm to analyze the speckle movements. This algorithm runs on a FPGA and is able to calculate a feedback value which is correlated to the thermal and coagulation induced tissue motion and thus the achieved damage. For different spot sizes (50-200 μm) and different exposure times (50-500 ms) the algorithm shows the ability to discriminate between different categories of retinal pigment epithelial damage ex-vivo in enucleated porcine eyes. Furthermore in-vivo experiments in rabbits show the ability of the system to determine tissue changes in living tissue during coagulation.

  16. Real-Time Monitoring of Psychotherapeutic Processes: Concept and Compliance

    PubMed Central

    Schiepek, Günter; Aichhorn, Wolfgang; Gruber, Martin; Strunk, Guido; Bachler, Egon; Aas, Benjamin

    2016-01-01

    Objective: The feasibility of a high-frequency real-time monitoring approach to psychotherapy is outlined and tested for patients' compliance to evaluate its integration to everyday practice. Criteria concern the ecological momentary assessment, the assessment of therapy-related cognitions and emotions, equidistant time sampling, real-time nonlinear time series analysis, continuous participative process control by client and therapist, and the application of idiographic (person-specific) surveys. Methods: The process-outcome monitoring is technically realized by an internet-based device for data collection and data analysis, the Synergetic Navigation System. Its feasibility is documented by a compliance study on 151 clients treated in an inpatient and a day-treatment clinic. Results: We found high compliance rates (mean: 78.3%, median: 89.4%) amongst the respondents, independent of the severity of symptoms or the degree of impairment. Compared to other diagnoses, the compliance rate was lower in the group diagnosed with personality disorders. Conclusion: The results support the feasibility of high-frequency monitoring in routine psychotherapy settings. Daily collection of psychological surveys allows for the assessment of highly resolved, equidistant time series data which gives insight into the nonlinear qualities of therapeutic change processes (e.g., pattern transitions, critical instabilities). PMID:27199837

  17. Remote, real-time monitoring of cyclones with microseisms

    NASA Astrophysics Data System (ADS)

    Jo, B. G.; Lee, W. D.; Schwab, F. A.

    2014-12-01

    Giving proper care to selecting microseisms from well isolated cyclones, these great oceanic storms can be monitored in real time by seismic recordings at stations 1200-4100 km distant from the cyclone's center. We treat ocean depths of 3.4-5.5 km. For the theoretically-computed microseism, which our procedure compares with the experimental data, we use a Green's-function approach in the frequency domain. Relating recorded displacement F and theoretical Green's function G, We have F(ω,r)=S(ω)G(ω,r) in which our only unknown is the generalized source function S(ω) and r is the distance to the center at any specific time. The basic result of this report is that the form of this function is A SN(ω), where A is a real constant increasing with the strength of the cyclone and SN(ω), is a positive real function of frequency, independent of cyclone-receiver separation and of cyclone strength. That is, for a given ocean basin, and a given receiver-region geology, at our current level of accuracy SN(ω) is the same for all cyclone strengths and cyclone-receiver separations. Using the multimode approach, we've developed the numerical method for computing the Green's function for multilayered oceanic structures. For each of the 4 selected cyclones, the source functions for all locations along the path show a consistency which demonstrates that the recorded microseisms are radiated from the cyclone. The extracted source function exhibits spectra that are characteristic of ocean waves generated by cyclonic winds. With knowledge of distance between the source and receiver, cyclone A is therefore trivial to monitor in real time from remote recordings. At the current time, the cyclone's strength—generalized source function—must be related empirically to the cyclone's maximum wind speed, areal extent, and lateral velocity.

  18. Real-time estimation of ionospheric delay using GPS measurements

    NASA Astrophysics Data System (ADS)

    Lin, Lao-Sheng

    1997-12-01

    When radio waves such as the GPS signals propagate through the ionosphere, they experience an extra time delay. The ionospheric delay can be eliminated (to the first order) through a linear combination of L1 and L2 observations from dual-frequency GPS receivers. Taking advantage of this dispersive principle, one or more dual- frequency GPS receivers can be used to determine a model of the ionospheric delay across a region of interest and, if implemented in real-time, can support single-frequency GPS positioning and navigation applications. The research objectives of this thesis were: (1) to develop algorithms to obtain accurate absolute Total Electron Content (TEC) estimates from dual-frequency GPS observables, and (2) to develop an algorithm to improve the accuracy of real-time ionosphere modelling. In order to fulfil these objectives, four algorithms have been proposed in this thesis. A 'multi-day multipath template technique' is proposed to mitigate the pseudo-range multipath effects at static GPS reference stations. This technique is based on the assumption that the multipath disturbance at a static station will be constant if the physical environment remains unchanged from day to day. The multipath template, either single-day or multi-day, can be generated from the previous days' GPS data. A 'real-time failure detection and repair algorithm' is proposed to detect and repair the GPS carrier phase 'failures', such as the occurrence of cycle slips. The proposed algorithm uses two procedures: (1) application of a statistical test on the state difference estimated from robust and conventional Kalman filters in order to detect and identify the carrier phase failure, and (2) application of a Kalman filter algorithm to repair the 'identified carrier phase failure'. A 'L1/L2 differential delay estimation algorithm' is proposed to estimate GPS satellite transmitter and receiver L1/L2 differential delays. This algorithm, based on the single-site modelling technique, is

  19. A real-time prediction of UTC

    NASA Astrophysics Data System (ADS)

    Thomas, Claudine; Allan, David W.

    1994-05-01

    The reference time scale for all scientific and technologic applications on the Earth, the Universal Coordinated Time (UTC), must be as stable, reliable, and accurate as possible. With this in view the BIPM and before it the BIH, have always calculated and then disseminated UTC with a delay of about 80 days. There are three fundamental reasons for doing this: (1) It takes some weeks for data, gathered from some 200 clocks spread world-wide, to be collected and for errors to be eliminated; (2) changes in clock rates can only be measured with high precision well after the fact; and (3) the measurement noise originating in time links, in particular using Loran-C, is smoothed out only when averaging over an extended period. Until mid-1992, the ultimate stability of UTC was reached at averaging times of about 100 days and corresponded to an Allan deviation sigma(sub y)(tau) of about 1,5x10(exp -14) then compared to the best primary clock in the world, the PTB CS2. For several years now, a predicted UTC has been computed by the USNO through an extrapolation of the values as published in deferred time by the BIPM. This is made available through the USNO Series 4, through the USNO Automated Data Service, and through GPS signals. Due to the instability of UTC, the poor predictability of the available clocks, and the intentional SA degradation of GPS signals, the real-time access to this extrapolated UTC has represented the true deferred-time UTC only to within several hundreds of nanoseconds.

  20. A real-time prediction of UTC

    NASA Technical Reports Server (NTRS)

    Thomas, Claudine; Allan, David W.

    1994-01-01

    The reference time scale for all scientific and technologic applications on the Earth, the Universal Coordinated Time (UTC), must be as stable, reliable, and accurate as possible. With this in view the BIPM and before it the BIH, have always calculated and then disseminated UTC with a delay of about 80 days. There are three fundamental reasons for doing this: (1) It takes some weeks for data, gathered from some 200 clocks spread world-wide, to be collected and for errors to be eliminated; (2) changes in clock rates can only be measured with high precision well after the fact; and (3) the measurement noise originating in time links, in particular using Loran-C, is smoothed out only when averaging over an extended period. Until mid-1992, the ultimate stability of UTC was reached at averaging times of about 100 days and corresponded to an Allan deviation sigma(sub y)(tau) of about 1,5x10(exp -14) then compared to the best primary clock in the world, the PTB CS2. For several years now, a predicted UTC has been computed by the USNO through an extrapolation of the values as published in deferred time by the BIPM. This is made available through the USNO Series 4, through the USNO Automated Data Service, and through GPS signals. Due to the instability of UTC, the poor predictability of the available clocks, and the intentional SA degradation of GPS signals, the real-time access to this extrapolated UTC has represented the true deferred-time UTC only to within several hundreds of nanoseconds.

  1. A tool for modeling concurrent real-time computation

    NASA Technical Reports Server (NTRS)

    Sharma, D. D.; Huang, Shie-Rei; Bhatt, Rahul; Sridharan, N. S.

    1990-01-01

    Real-time computation is a significant area of research in general, and in AI in particular. The complexity of practical real-time problems demands use of knowledge-based problem solving techniques while satisfying real-time performance constraints. Since the demands of a complex real-time problem cannot be predicted (owing to the dynamic nature of the environment) powerful dynamic resource control techniques are needed to monitor and control the performance. A real-time computation model for a real-time tool, an implementation of the QP-Net simulator on a Symbolics machine, and an implementation on a Butterfly multiprocessor machine are briefly described.

  2. Real-time data flow and product generating for GNSS

    NASA Technical Reports Server (NTRS)

    Muellerschoen, Ronald J.; Caissy, Mark

    2004-01-01

    The last IGS workshop with the theme 'Towards Real-Time' resulted in the design of a prototype for real-time data and sharing within the IGS. A prototype real-time network is being established that will serve as a test bed for real-time activities within the IGS. We review the developments of the prototype and discuss some of the existing methods and related products of real-time GNSS systems. Recommendations are made concerning real-time data distribution and product generation.

  3. Filming protein fibrillogenesis in real time

    NASA Astrophysics Data System (ADS)

    Bella, Angelo; Shaw, Michael; Ray, Santanu; Ryadnov, Maxim G.

    2014-12-01

    Protein fibrillogenesis is a universal tool of nano-to-micro scale construction supporting different forms of biological function. Its exploitable potential in nanoscience and technology is substantial, but the direct observation of homogeneous fibre growth able to underpin a kinetic-based rationale for building customized nanostructures in situ is lacking. Here we introduce a kinetic model of de novo protein fibrillogenesis which we imaged at the nanoscale and in real time, filmed. The model helped to reveal that, in contrast to heterogeneous amyloid assemblies, homogeneous protein recruitment is principally characterized by uniform rates of cooperative growth at both ends of growing fibers, bi-directional growth, with lateral growth arrested at a post-seeding stage. The model provides a foundation for in situ engineering of sequence-prescribed fibrous architectures.

  4. Near real-time stereo vision system

    NASA Astrophysics Data System (ADS)

    Matthies, Larry H.; Anderson, Charles H.

    1991-12-01

    The apparatus for a near real-time stereo vision system for use with a robotic vehicle is described. The system is comprised of two cameras mounted on three-axis rotation platforms, image-processing boards, a CPU, and specialized stereo vision algorithms. Bandpass-filtered image pyramids are computed, stereo matching is performed by least-squares correlation, and confidence ranges are estimated by means of Bayes' theorem. In particular, Laplacian image pyramids are built and disparity maps are produced from the 60 x 64 level of the pyramids at rates of up to 2 seconds per image pair. The first autonomous cross-country robotic traverses (of up to 100 meters) have been achieved using the stereo vision system of the present invention with all computing done onboard the vehicle. The overall approach disclosed herein provides a unifying paradigm for practical domain-independent stereo ranging.

  5. Near real-time stereo vision system

    NASA Astrophysics Data System (ADS)

    Anderson, Charles H.; Matthies, Larry H.

    1993-01-01

    The apparatus for a near real-time stereo vision system for use with a robotic vehicle is described. The system is comprised of two cameras mounted on three-axis rotation platforms, image-processing boards, a CPU, and specialized stereo vision algorithms. Bandpass-filtered image pyramids are computed, stereo matching is performed by least-squares correlation, and confidence ranges are estimated by means of Bayes' theorem. In particular, Laplacian image pyramids are built and disparity maps are produced from the 60 x 64 level of the pyramids at rates of up to 2 seconds per image pair. The first autonomous cross-country robotic traverses (of up to 100 meters) have been achieved using the stereo vision system of the present invention with all computing done onboard the vehicle. The overall approach disclosed herein provides a unifying paradigm for practical domain-independent stereo ranging.

  6. REAL TIME DATA FOR REMEDIATION ACTIVITIES [11505

    SciTech Connect

    BROCK CT

    2011-01-13

    Health physicists from the CH2M HILL Plateau Remediation Company collaborated with Berkeley Nucleonics Corporation to modify the SAM 940 isotope identifier instrument to be used for nuclear waste remediation. These modifications coupled with existing capabilities of the SAM 940 have proven to be invaluable during remediation activities, reducing disposal costs by allowing swift remediation of targeted areas that have been identified as having isotopes of concern (IOC), and eliminating multiple visits to sites by declaring an excavation site clear of IOCs before demobilizing from the site. These advantages are enabled by accumulating spectral data for specific isotopes that is nearly 100 percent free of false positives, which are filtered out in 'real time.'

  7. Real-time slicing of data space

    SciTech Connect

    Crawfis, R.A.

    1996-07-01

    Real-time rendering of iso-contour surfaces is problematic for large complex data sets. In this paper, an algorithm is presented that allows very rapid representation of an interval set surrounding a iso-contour surface. The algorithm draws upon three main ideas. A fast indexing scheme is used to select only those data points near the contour surface. Hardware assisted splatting is then employed on these data points to produce a volume rendering of the interval set. Finally, by shifting a small window through the indexing scheme or data space, animated volumes are produced showing the changing contour values. In addition to allowing fast selection and rendering of the data, the indexing scheme allows a much compressed representation of the data by eliminating ``noise`` data points.

  8. In-line real time air monitor

    DOEpatents

    Wise, M.B.; Thompson, C.V.

    1998-07-14

    An in-line gas monitor capable of accurate gas composition analysis in a continuous real time manner even under strong applied vacuum conditions operates by mixing an air sample with helium forming a sample gas in two complementary sample loops embedded in a manifold which includes two pairs of 3-way solenoid valves. The sample gas is then analyzed in an ion trap mass spectrometer on a continuous basis. Two valve drivers actuate the two pairs of 3-way valves in a reciprocating fashion, so that there is always flow through the in-line gas monitor via one or the other of the sample loops. The duty cycle for the two pairs of 3-way valves is varied by tuning the two valve drivers to a duty cycle typically between 0.2 to 0.7 seconds. 3 figs.

  9. Real-time, face recognition technology

    SciTech Connect

    Brady, S.

    1995-11-01

    The Institute for Scientific Computing Research (ISCR) at Lawrence Livermore National Laboratory recently developed the real-time, face recognition technology KEN. KEN uses novel imaging devices such as silicon retinas developed at Caltech or off-the-shelf CCD cameras to acquire images of a face and to compare them to a database of known faces in a robust fashion. The KEN-Online project makes that recognition technology accessible through the World Wide Web (WWW), an internet service that has recently seen explosive growth. A WWW client can submit face images, add them to the database of known faces and submit other pictures that the system tries to recognize. KEN-Online serves to evaluate the recognition technology and grow a large face database. KEN-Online includes the use of public domain tools such as mSQL for its name-database and perl scripts to assist the uploading of images.

  10. Filming protein fibrillogenesis in real time

    PubMed Central

    Bella, Angelo; Shaw, Michael; Ray, Santanu; Ryadnov, Maxim G.

    2014-01-01

    Protein fibrillogenesis is a universal tool of nano-to-micro scale construction supporting different forms of biological function. Its exploitable potential in nanoscience and technology is substantial, but the direct observation of homogeneous fibre growth able to underpin a kinetic-based rationale for building customized nanostructures in situ is lacking. Here we introduce a kinetic model of de novo protein fibrillogenesis which we imaged at the nanoscale and in real time, filmed. The model helped to reveal that, in contrast to heterogeneous amyloid assemblies, homogeneous protein recruitment is principally characterized by uniform rates of cooperative growth at both ends of growing fibers, bi-directional growth, with lateral growth arrested at a post-seeding stage. The model provides a foundation for in situ engineering of sequence-prescribed fibrous architectures. PMID:25519825

  11. Real-time value-driven diagnosis

    NASA Technical Reports Server (NTRS)

    Dambrosio, Bruce

    1995-01-01

    Diagnosis is often thought of as an isolated task in theoretical reasoning (reasoning with the goal of updating our beliefs about the world). We present a decision-theoretic interpretation of diagnosis as a task in practical reasoning (reasoning with the goal of acting in the world), and sketch components of our approach to this task. These components include an abstract problem description, a decision-theoretic model of the basic task, a set of inference methods suitable for evaluating the decision representation in real-time, and a control architecture to provide the needed continuing coordination between the agent and its environment. A principal contribution of this work is the representation and inference methods we have developed, which extend previously available probabilistic inference methods and narrow, somewhat, the gap between probabilistic and logical models of diagnosis.

  12. In-line real time air monitor

    DOEpatents

    Wise, Marcus B.; Thompson, Cyril V.

    1998-01-01

    An in-line gas monitor capable of accurate gas composition analysis in a continuous real time manner even under strong applied vacuum conditions operates by mixing an air sample with helium forming a sample gas in two complementary sample loops embedded in a manifold which includes two pairs of 3-way solenoid valves. The sample gas is then analyzed in an ion trap mass spectrometer on a continuous basis. Two valve drivers actuate the two pairs of 3-way valves in a reciprocating fashion, so that there is always flow through the in-line gas monitor via one or the other of the sample loops. The duty cycle for the two pairs of 3-way valves is varied by tuning the two valve drivers to a duty cycle typically between 0.2 to 0.7 seconds.

  13. A operational real time flood forecasting chain

    NASA Astrophysics Data System (ADS)

    Arena, N.; Cavallo, A.; Giannoni, F.; Turato, B.

    2003-04-01

    Extreme floods forecast represent an important modeling challenge for which it is crucial to utilize the simplest model representations that capture the dominant controls of extreme flood response. For extreme floods, the spatio-temporal structure of rainfall and drainage network structure often play a fundamental role. The integrated meteo-hydrologic real time forecasting chain in use at the Hydrometorological Center of Liguria Region is presented with particular regard to a specific case study. The meteorological forecasts are performed through the use of traditional means as Numerical Weather Predictions models at different resolutions and an innovative tool for the now-casting prediction as the meteorological Radar. The elements of the hydrologic model are a Hortonian infiltration model and a GIUH-based network response model. The basin scales of interest range from approximately 50 - 1,000 km2. The case study is the November 23-26, 2002 event.

  14. Real-time snapshot hyperspectral imaging endoscope

    PubMed Central

    Kester, Robert T.; Bedard, Noah; Gao, Liang; Tkaczyk, Tomasz S.

    2011-01-01

    Hyperspectral imaging has tremendous potential to detect important molecular biomarkers of early cancer based on their unique spectral signatures. Several drawbacks have limited its use for in vivo screening applications: most notably the poor temporal and spatial resolution, high expense, and low optical throughput of existing hyperspectral imagers. We present the development of a new real-time hyperspectral endoscope (called the image mapping spectroscopy endoscope) based on an image mapping technique capable of addressing these challenges. The parallel high throughput nature of this technique enables the device to operate at frame rates of 5.2 frames per second while collecting a (x, y, λ) datacube of 350 × 350 × 48. We have successfully imaged tissue in vivo, resolving a vasculature pattern of the lower lip while simultaneously detecting oxy-hemoglobin. PMID:21639573

  15. A Measure of Real-Time Intelligence

    NASA Astrophysics Data System (ADS)

    Gavane, Vaibhav

    2013-03-01

    We propose a new measure of intelligence for general reinforcement learning agents, based on the notion that an agent's environment can change at any step of execution of the agent. That is, an agent is considered to be interacting with its environment in real-time. In this sense, the resulting intelligence measure is more general than the universal intelligence measure (Legg and Hutter, 2007) and the anytime universal intelligence test (Hernández-Orallo and Dowe, 2010). A major advantage of the measure is that an agent's computational complexity is factored into the measure in a natural manner. We show that there exist agents with intelligence arbitrarily close to the theoretical maximum, and that the intelligence of agents depends on their parallel processing capability. We thus believe that the measure can provide a better evaluation of agents and guidance for building practical agents with high intelligence.

  16. Real-Time Inspection Of Currency

    NASA Astrophysics Data System (ADS)

    Blazek, Henry

    1986-12-01

    An automatic inspection machine, designed and manufactured by the Perkin-Elmer Corporation for the U.S. Bureau of Engraving and Printing, is capable of real-time inspection of currency at rates compatible with the output of modern high-speed printing presses. Inspection is accomplished by comparing test notes (in 32-per-sheet format) with reference notes stored in the memory of a digital computer. This paper describes the development of algorithms for detecting defective notes, one of the key problems solved during the development of the inspection system. Results achieved on an analytical model, used for predicting probability of false alarms and probability of detecting typically defective notes, are compared to those obtained by system simulation.

  17. Cerebral Autoregulation Real-Time Monitoring

    PubMed Central

    Tsalach, Adi; Ratner, Eliahu; Lokshin, Stas; Silman, Zmira; Breskin, Ilan; Budin, Nahum; Kamar, Moshe

    2016-01-01

    Cerebral autoregulation is a mechanism which maintains constant cerebral blood flow (CBF) despite changes in mean arterial pressure (MAP). Assessing whether this mechanism is intact or impaired and determining its boundaries is important in many clinical settings, where primary or secondary injuries to the brain may occur. Herein we describe the development of a new ultrasound tagged near infra red light monitor which tracks CBF trends, in parallel, it continuously measures blood pressure and correlates them to produce a real time autoregulation index. Its performance is validated in both in-vitro experiment and a pre-clinical case study. Results suggest that using such a tool, autoregulation boundaries as well as its impairment or functioning can be identified and assessed. It may therefore assist in individualized MAP management to ensure adequate organ perfusion and reduce the risk of postoperative complications, and might play an important role in patient care. PMID:27571474

  18. Public Science with Real-Time Experiments

    NASA Astrophysics Data System (ADS)

    Lenardic, A.

    2013-12-01

    One of the best ways for professional scientists to engage in public outreach is to get outside of the university and/or lab walls and go out into the public. That is, go to public spaces to do some science experiments with the public - this includes students of all ages that constitute that public. Technological advance in portable measurement gear now allow one to do real, or near real, time experiments in outdoor, public spaces. We have been running a meta-experiment of this sort, aimed at the public display of science, for about a year now in Houston TX at the Lee and Joe Jamail Skatepark. The project goes under the title of Sk8Lab Houston and has introduced students of all ages to the power of scientific experimentation. We bring a portable science pack with us to the park. The pack has a range of wireless measurement gear that allow experiments to be done on the spot. Some of the experiments are designed by us but many are designed on by whoever suggests them to us that day. Over time the Sk8Lab scientists have built up a level of "trust" with the people who frequent the park (no one feels like we are gonna grade them at the park and they know that the learning is not on some regimented clock). This has broken down some learning walls and allowed for a more informal mode of exploration and a more genuine mode of experimentation (as compared to what often happens in class labs when students feel like they are just being forced to reproduce some known result). We will describe some of the test case experiments we have run and also discuss some of the trials, tribulations, and happy successes (many unplanned) along the way.

  19. Compact snapshot real-time imaging spectrometer

    NASA Astrophysics Data System (ADS)

    Kudenov, Michael W.; Dereniak, Eustace L.

    2011-11-01

    The described spectral imaging system, referred to as a Snapshot Hyperspectral Imaging Fourier Transform (SHIFT) spectrometer, is capable of acquiring spectral image data of a scene in a single integration of a camera, is ultra-compact, inexpensive (commercial off-the-shelf), has no moving parts, and can produce datacubes (x, y, λ) in real time. Based on the multiple-image FTS originally developed by A. Hirai [1], the presented device offers significant advantages over his original implementation. Namely, its birefringent nature results in a common-path interferometer which makes the spectrometer insensitive to vibration. Furthermore, it enables the potential of making the instrument ultra-compact, thereby improving the portability of the sensor. By combining a birefringent interferometer with a lenslet array, the entire spectrometer consumes approximately 15×15×20 mm3, excluding the imaging camera. The theory of the birefringent FTS is provided, followed by details of its specific embodiment and a laboratory proof of concept of the sensor. Post-processing is currently accomplished in Matlab, but progress is underway in developing real-time reconstruction capabilities with software programmed on a graphics processing unit (GPU). It is anticipated that processing of >30 datacubes per second can be achieved with modest GPU hardware, with spatial/spectral data of or exceeding 256×256 spatial resolution elements and 60 spectral bands over the visible (400-800 nm) spectrum. Data were collected outdoors, demonstrating the sensor's ability to resolve spectral signatures in standard outdoor lighting and environmental conditions as well as retinal imaging.

  20. Subsystem real-time time dependent density functional theory.

    PubMed

    Krishtal, Alisa; Ceresoli, Davide; Pavanello, Michele

    2015-04-21

    We present the extension of Frozen Density Embedding (FDE) formulation of subsystem Density Functional Theory (DFT) to real-time Time Dependent Density Functional Theory (rt-TDDFT). FDE is a DFT-in-DFT embedding method that allows to partition a larger Kohn-Sham system into a set of smaller, coupled Kohn-Sham systems. Additional to the computational advantage, FDE provides physical insight into the properties of embedded systems and the coupling interactions between them. The extension to rt-TDDFT is done straightforwardly by evolving the Kohn-Sham subsystems in time simultaneously, while updating the embedding potential between the systems at every time step. Two main applications are presented: the explicit excitation energy transfer in real time between subsystems is demonstrated for the case of the Na4 cluster and the effect of the embedding on optical spectra of coupled chromophores. In particular, the importance of including the full dynamic response in the embedding potential is demonstrated. PMID:25903875

  1. The future of time and frequency dissemination

    NASA Technical Reports Server (NTRS)

    Levine, Judah

    1994-01-01

    I will try to extrapolate the changes in the dissemination of time and frequency information that have taken place during the last 25 years to predict the future developments both in the methods of disseminating time and frequency and in the kinds of customers we will be asked to serve. Two important developments are likely to play pivotal roles in driving the evolution of dissemination. The first is the commercial availability of very high quality clocks -- devices whose performance may eventually rival that of the current generation of primary frequency standards. The widespread use of these devices may blur the traditional distinction between client and server, and may replace it with a more symmetrical interchange of data among peers. The second is the increasing demand for digital time and frequency information driven by the increasing sophistication of everything from traffic lights to electric power meters. The needs of these individual users may not tax the state of the art of primary frequency standards in principle, but their large numbers and wide geographical distribution present a technological challenge that is difficult to meet at a reasonable price using existing methods. Some of these problems may be solved (or at least addressed) using developments in communications and consumer electronics such as the increasing use of fiber-optic telephone circuits and the increasing bandwidth and sophistication of the cable network used to transmit television pictures. To be useful, these advances in hardware must stimulate parallel advances in software algorithms and methods. These advances are more difficult to predict with great confidence, but the developments of the last few years will be examined to provide some indications of the future.

  2. The Murchison Widefield Array Real-Time System

    NASA Astrophysics Data System (ADS)

    Mitchell, Daniel; Greenhill, L.; Wayth, R.; Ord, S.; Sault, R.; Doeleman, S.; Kasper, J.; Morales, M.

    2007-12-01

    The Murchison Widefield Array (MWA) is a next-generation radio telescope being built in Australia to study the early universe, the sun, space weather, and time variability of the radio sky. The real-time data processing back-end of the MWA must calibrate and image the output of a 512-antenna correlator, in 4096 frequency channels and 4 polarizations, reducing 16 GB/s (1.4 Peta-Bytes/day) of input visibilities to images that can be stored for off-line science processing. The real-time system consists of a visibility integrator, a system to measure ionospheric and instrumental effects towards many point sources, all-sky ionospheric and instrumental calibration systems, and an imaging pipeline, which incorporates gridding, imaging, image de-distortion, Stokes conversion, and coordinate conversion. All of these will run in software on a tera-flop computing cluster. Here we present an overview of the real-time system and the main data products it provides to the science packages.

  3. Optical techniques for time and frequency transfer

    NASA Technical Reports Server (NTRS)

    Baumont, Francoise; Gaignebet, Jean

    1994-01-01

    Light has been used as a means for time synchronization for a long time. The flight time was supposed to be negligible. The first scientific determination of the velocity of the light was done by measuring a round trip flight time on a given distance. The well known flying clock experiment leading to Einstein's General Relativity is another example. The advent of lasers, particularly short pulse and modulated ones, as well as the improvements of the timing equipments have led to new concepts for time and frequency transfer. We describe some experiments using different techniques and configurations which have been proposed and tested in this field since the beginning of the space age. Added to that, we set out advantages, drawbacks, and performances achieved in the different cases.

  4. Real Time Seismic Prediction while Drilling

    NASA Astrophysics Data System (ADS)

    Schilling, F. R.; Bohlen, T.; Edelmann, T.; Kassel, A.; Heim, A.; Gehring, M.; Lüth, S.; Giese, R.; Jaksch, K.; Rechlin, A.; Kopf, M.; Stahlmann, J.; Gattermann, J.; Bruns, B.

    2009-12-01

    Efficient and safe drilling is a prerequisite to enhance the mobility of people and goods, to improve the traffic as well as utility infrastructure of growing megacities, and to ensure the growing energy demand while building geothermal and in hydroelectric power plants. Construction within the underground is often building within the unknown. An enhanced risk potential for people and the underground building may arise if drilling enters fracture zones, karsts, brittle rocks, mixed solid and soft rocks, caves, or anthropogenic obstacles. Knowing about the material behavior ahead of the drilling allows reducing the risk during drilling and construction operation. In drilling operations direct observations from boreholes can be complemented with geophysical investigations. In this presentation we focus on “real time” seismic prediction while drilling which is seen as a prerequisite while using geophysical methods in modern drilling operations. In solid rocks P- and S-wave velocity, refraction and reflection as well as seismic wave attenuation can be used for the interpretation of structures ahead of the drilling. An Integrated Seismic Imaging System (ISIS) for exploration ahead of a construction is used, where a pneumatic hammer or a magnetostrictive vibration source generate repetitive signals behind the tunneling machine. Tube waves are generated which travel along the tunnel to the working face. There the tube waves are converted to mainly S- but also P-Waves which interact with the formation ahead of the heading face. The reflected or refracted waves travel back to the working front are converted back to tube waves and recorded using three-component geophones which are fit into the tips of anchor rods. In near real time, the ISIS software allows for an integrated 3D imaging and interpretation of the observed data, geological and geotechnical parameters. Fracture zones, heterogeneities, and variations in the rock properties can be revealed during the drilling

  5. Frequency and time generation and control

    NASA Technical Reports Server (NTRS)

    Bloch, M.

    1981-01-01

    High precision quartz crystal oscillators, cesium beam atomic resonators, and cesium beam atomic standards for time and frequency generation equipment for ground, airborne, and space use are described. Because of the high risk factors involved, and the commercial applications of these products being too far off in the future, private capital for research and development is difficult if not impossible to obtain. More specific analysis and recommendations to overcome these difficulties are objectively presented.

  6. Time delay measurement in the frequency domain

    DOE PAGESBeta

    Durbin, Stephen M.; Liu, Shih -Chieh; Dufresne, Eric M.; Li, Yuelin; Wen, Haidan

    2015-08-06

    Pump–probe studies at synchrotrons using X-ray and laser pulses require accurate determination of the time delay between pulses. This becomes especially important when observing ultrafast responses with lifetimes approaching or even less than the X-ray pulse duration (~100 ps). The standard approach of inspecting the time response of a detector sensitive to both types of pulses can have limitations due to dissimilar pulse profiles and other experimental factors. Here, a simple alternative is presented, where the frequency response of the detector is monitored versus time delay. Measurements readily demonstrate a time resolution of ~1 ps. Improved precision is possible bymore » simply extending the data acquisition time.« less

  7. Time delay measurement in the frequency domain

    SciTech Connect

    Durbin, Stephen M.; Liu, Shih -Chieh; Dufresne, Eric M.; Li, Yuelin; Wen, Haidan

    2015-08-06

    Pump–probe studies at synchrotrons using X-ray and laser pulses require accurate determination of the time delay between pulses. This becomes especially important when observing ultrafast responses with lifetimes approaching or even less than the X-ray pulse duration (~100 ps). The standard approach of inspecting the time response of a detector sensitive to both types of pulses can have limitations due to dissimilar pulse profiles and other experimental factors. Here, a simple alternative is presented, where the frequency response of the detector is monitored versus time delay. Measurements readily demonstrate a time resolution of ~1 ps. Improved precision is possible by simply extending the data acquisition time.

  8. Clinical experience with real-time ultrasound

    NASA Astrophysics Data System (ADS)

    Chimiak, William J.; Wolfman, Neil T.; Covitz, Wesley

    1995-05-01

    After testing the extended multimedia interface (EMMI) product which is an asynchronous transmission mode (ATM) user to network interface (UNI) of AT&T at the Society for Computer Applications in Radiology conference in Winston-Salem, the Department of Radiology together with AT&T are implementing a tele-ultrasound system to combine real- time ultrasound with the static imaging features of more traditional digital ultrasound systems. Our current ultrasound system archives digital images to an optical disk system. Static images are sent using our digital radiology systems. This could be transferring images from one digital imaging and communications (DICOM)-compliant machine to another, or the current image transfer methodologies. The prototype of a live ultrasound system using the EMMI demonstrated the feasibility of doing live ultrasound. We now are developing the scenarios using a mix of the two methodologies. Utilizing EMMI technology, radiologists at the BGSM review at a workstation both static images and real-time scanning done by a technologist on patients at a remote site in order to render on-line primary diagnosis. Our goal is to test the feasibility of operating an ultrasound laboratory at a remote site utilizing a trained technologist without the necessity of having a full-time radiologist at that site. Initial plans are for a radiologist to review an initial set of static images on a patient taken by the technologist. If further scanning is required, the EMMI is used to transmit real-time imaging and audio using the audio input of a standard microphone system and the National Television Standards Committee (NTSC) output of the ultrasound equipment from the remote site to the radiologist in the department review station. The EMMI digitally encodes this data and places it in an ATM format. This ATM data stream goes to the GCNS2000 and then to the other EMMI where the ATM data stream is decoded into the live studies and voice communication which are then

  9. Time-Frequency Analysis Reveals Pairwise Interactions in Insect Swarms

    NASA Astrophysics Data System (ADS)

    Puckett, James G.; Ni, Rui; Ouellette, Nicholas T.

    2015-06-01

    The macroscopic emergent behavior of social animal groups is a classic example of dynamical self-organization, and is thought to arise from the local interactions between individuals. Determining these interactions from empirical data sets of real animal groups, however, is challenging. Using multicamera imaging and tracking, we studied the motion of individual flying midges in laboratory mating swarms. By performing a time-frequency analysis of the midge trajectories, we show that the midge behavior can be segmented into two distinct modes: one that is independent and composed of low-frequency maneuvers, and one that consists of higher-frequency nearly harmonic oscillations conducted in synchrony with another midge. We characterize these pairwise interactions, and make a hypothesis as to their biological function.

  10. Time-Frequency Analysis Reveals Pairwise Interactions in Insect Swarms.

    PubMed

    Puckett, James G; Ni, Rui; Ouellette, Nicholas T

    2015-06-26

    The macroscopic emergent behavior of social animal groups is a classic example of dynamical self-organization, and is thought to arise from the local interactions between individuals. Determining these interactions from empirical data sets of real animal groups, however, is challenging. Using multicamera imaging and tracking, we studied the motion of individual flying midges in laboratory mating swarms. By performing a time-frequency analysis of the midge trajectories, we show that the midge behavior can be segmented into two distinct modes: one that is independent and composed of low-frequency maneuvers, and one that consists of higher-frequency nearly harmonic oscillations conducted in synchrony with another midge. We characterize these pairwise interactions, and make a hypothesis as to their biological function. PMID:26197145

  11. Ames Lab 101: Real-Time 3D Imaging

    ScienceCinema

    Zhang, Song

    2012-08-29

    Ames Laboratory scientist Song Zhang explains his real-time 3-D imaging technology. The technique can be used to create high-resolution, real-time, precise, 3-D images for use in healthcare, security, and entertainment applications.

  12. Real-time multi-view deconvolution

    PubMed Central

    Schmid, Benjamin; Huisken, Jan

    2015-01-01

    Summary: In light-sheet microscopy, overall image content and resolution are improved by acquiring and fusing multiple views of the sample from different directions. State-of-the-art multi-view (MV) deconvolution simultaneously fuses and deconvolves the images in 3D, but processing takes a multiple of the acquisition time and constitutes the bottleneck in the imaging pipeline. Here, we show that MV deconvolution in 3D can finally be achieved in real-time by processing cross-sectional planes individually on the massively parallel architecture of a graphics processing unit (GPU). Our approximation is valid in the typical case where the rotation axis lies in the imaging plane. Availability and implementation: Source code and binaries are available on github (https://github.com/bene51/), native code under the repository ‘gpu_deconvolution’, Java wrappers implementing Fiji plugins under ‘SPIM_Reconstruction_Cuda’. Contact: bschmid@mpi-cbg.de or huisken@mpi-cbg.de Supplementary information: Supplementary data are available at Bioinformatics online. PMID:26112291

  13. Real-Time Principal-Component Analysis

    NASA Technical Reports Server (NTRS)

    Duong, Vu; Duong, Tuan

    2005-01-01

    A recently written computer program implements dominant-element-based gradient descent and dynamic initial learning rate (DOGEDYN), which was described in Method of Real-Time Principal-Component Analysis (NPO-40034) NASA Tech Briefs, Vol. 29, No. 1 (January 2005), page 59. To recapitulate: DOGEDYN is a method of sequential principal-component analysis (PCA) suitable for such applications as data compression and extraction of features from sets of data. In DOGEDYN, input data are represented as a sequence of vectors acquired at sampling times. The learning algorithm in DOGEDYN involves sequential extraction of principal vectors by means of a gradient descent in which only the dominant element is used at each iteration. Each iteration includes updating of elements of a weight matrix by amounts proportional to a dynamic initial learning rate chosen to increase the rate of convergence by compensating for the energy lost through the previous extraction of principal components. In comparison with a prior method of gradient-descent-based sequential PCA, DOGEDYN involves less computation and offers a greater rate of learning convergence. The sequential DOGEDYN computations require less memory than would parallel computations for the same purpose. The DOGEDYN software can be executed on a personal computer.

  14. Real-time optoacoustic monitoring of stroke

    NASA Astrophysics Data System (ADS)

    Kneipp, Moritz; Turner, Jake; Hambauer, Sebastian; Krieg, Sandro M.; Lehmberg, Jens; Lindauer, Ute; Razansky, Daniel

    2014-03-01

    Characterizing disease progression and identifying possible therapeutic interventions in stroke is greatly aided by the use of longitudinal function imaging studies. In this study, we investigate the applicability of real-time multispectral optoacoustic tomography (MSOT) as a tool for non-invasive monitoring of the progression of stroke in the whole brain. The middle cerebral artery occlusion (MCAO) method was used to induce stroke. Mice were imaged under isoflurane anesthesia preoperatively and at several time points during and after the 60-minute occlusion. The animals were sacrificed after 24 hours and their excised brains frozen at -80°C for sectioning. The cryosection were stained using H&E staining to identify the ischemic lesion. Major vessels are readily identifiable in the whole mouse head in the in vivo optoacoustic scans. During ischemia, a reduction in cerebral blood volume is detectable in the cortex. Post ischemia, spectral unmixing of the optoacoustic signals shows an asymmetry of the deoxygenated hemoglobin in the hemisphere affected by MCAO. This hypoxic area was mainly located around the boundary of the ischemic lesion and was therefore identified as the ischemic penumbra. Non-invasive functional MSOT imaging is able to visualize the hypoxic penumbra in brains affected by stroke. Stopping the spread of the infarct area and revitalizing the penumbra is central in stroke research, this new imaging technique may therefore prove to be a valuable tool in the monitoring and developing new treatments.

  15. Development and application of a real-time capacitive sensor.

    PubMed

    Wongkittisuksa, Booncharoen; Limsakul, Chusak; Kanatharana, Proespichaya; Limbut, Warakorn; Asawatreratanakul, Punnee; Dawan, Supaporn; Loyprasert, Suchera; Thavarungkul, Panote

    2011-01-15

    A real-time capacitive sensor based on a potentiostatic step method was developed. It can display in real-time the evoked current waveform, capacitance and the electrical resistance of elements serially connected to the insulation layer on the electrode as a function of time as well as the ohmic resistance of the insulation layer. These features enable the user to observe the association and dissociation of the affinity binding pairs and to evaluate the insulating property of the electrode surface during measurement. The system allows the setting of potential pulse height, pulse interval, gain, filter, and sampling frequency, enabling the system to be more flexible. The performance of the system was firstly evaluated with equivalent circuits. Under suitable parameter settings it provided good accuracy of both the capacitance and resistance. Using the affinity binding pair of human serum albumin (HSA) and anti human serum albumin (anti-HSA) the measured capacitance change was used for the direct detection of HSA. The developed system provided the same sensitivity as the commercially available potentiostat (P>0.05). The proposed system was then applied to analyse HSA in real urine samples and the results agreed well with the immunoturbidimetric assay (P>0.05). The proposed system can be applied for capacitance measurement to directly detect other target analytes using different affinity binding pairs. Other applications such as kinetics analysis of the interaction between affinity bindings, thickness analysis, and the study of the insulation property of the modified layer are also promising. PMID:21087852

  16. Information and data real time transmission acoustic underwater system: TRIDENT

    NASA Astrophysics Data System (ADS)

    Trubuil, Joel; Labat, Joel; Lapierre, Gerard

    2001-05-01

    The objective of the Groupe d'Etudes Sous-Marines de l'Atlantique (GESMA) is to develop a robust high data rate acoustic link. A real-time receiver recently developed at ENST Bretagne has just been designed to cope with all perturbations induced by such harsh channels. In order to cope with channel features, a spatio-temporal equalizer introduced by J. Labat et al. [Brevet FT no. 9914844, ``Perfectionnements aux dispositifs d'galisation adaptative pour recepteurs de systemes de communications numriques,'' Nov. 1999] was recently implemented and evaluated. This equalizer is the core of the receiver platform [Trubuil et al., ``Real-time high data rate acoustic link based on spatio temporal blind equalization: the TRIDENT acoustic system,'' OCEANS 2002]. This paper provides an overview of this project. The context of the study and the design of high data rate acoustic link are presented. Last Brest harbor experiments (2002, 2003) are described. The real time horizontal acoustic link performances are evaluated. Two carriers frequencies are available (20, 35 kHz). Acoustic communications for bit rate ranging from 10 to 20 kbps and for channel length (shallow water) ranging from 500 to 4000 m have been conducted successfully over several hours.

  17. Real Time Turbulence Estimation Using Doppler Lidar Measurements

    NASA Astrophysics Data System (ADS)

    Rottner, Lucie; Baehr, Christophe

    2016-06-01

    A preliminary work on a new way to estimate atmospheric turbulence using high-frequency Doppler lidar measurements is presented. The turbulence estimations are based on wind reconstruction using 3D Doppler lidar observations and a particle filter. The suggested reconstruction algorithm links the lidar observations to numerical particles to obtain turbulence estimations every time new observations are available. The high frequency of the estimations is a new point which is detailed and discussed. Moreover, the presented algorithm ables to reconstruct the wind in three dimensions in the observed volume. We have thus locally access to the spatial variability of the turbulent atmosphere. The suggested algorithm is applied to a set of real observations. The obtained results are very encouraging : they show significant improvements on turbulent parameter estimations.

  18. A Low Complexity Architecture for OFCDM Downlink Transmitter Using Joint Time-Frequency Spreading and IFFT

    NASA Astrophysics Data System (ADS)

    Dan, Lilin; Xiao, Yue; Ni, Wei; Li, Shaoqian

    In this letter, a low complexity transmitter is proposed for the downlinks of orthogonal frequency code division multiplexing (OFCDM) systems. The principle is based on a joint time-frequency spreading and inverse fast Fourier transform (TFS-IFFT), which combines the frequency spreading with partial stages of IFFT, so as to simplify the real-time processing. Compared with the conventional one, the proposed OFCDM transmitter is of lower real-time computational complexity, especially for those with large spreading factor or low modulation level. Furthermore, the proposed TFS-IFFT can also be applied to other frequency spreading systems, such as MC-CDMA, for complexity reduction.

  19. CRANS - CONFIGURABLE REAL-TIME ANALYSIS SYSTEM

    NASA Technical Reports Server (NTRS)

    Mccluney, K.

    1994-01-01

    In a real-time environment, the results of changes or failures in a complex, interconnected system need evaluation quickly. Tabulations showing the effects of changes and/or failures of a given item in the system are generally only useful for a single input, and only with regard to that item. Subsequent changes become harder to evaluate as combinations of failures produce a cascade effect. When confronted by multiple indicated failures in the system, it becomes necessary to determine a single cause. In this case, failure tables are not very helpful. CRANS, the Configurable Real-time ANalysis System, can interpret a logic tree, constructed by the user, describing a complex system and determine the effects of changes and failures in it. Items in the tree are related to each other by Boolean operators. The user is then able to change the state of these items (ON/OFF FAILED/UNFAILED). The program then evaluates the logic tree based on these changes and determines any resultant changes to other items in the tree. CRANS can also search for a common cause for multiple item failures, and allow the user to explore the logic tree from within the program. A "help" mode and a reference check provide the user with a means of exploring an item's underlying logic from within the program. A commonality check determines single point failures for an item or group of items. Output is in the form of a user-defined matrix or matrices of colored boxes, each box representing an item or set of items from the logic tree. Input is via mouse selection of the matrix boxes, using the mouse buttons to toggle the state of the item. CRANS is written in C-language and requires the MIT X Window System, Version 11 Revision 4 or Revision 5. It requires 78K of RAM for execution and a three button mouse. It has been successfully implemented on Sun4 workstations running SunOS, HP9000 workstations running HP-UX, and DECstations running ULTRIX. No executable is provided on the distribution medium; however

  20. Real-time support for high performance aircraft operation

    NASA Technical Reports Server (NTRS)

    Vidal, Jacques J.

    1989-01-01

    The feasibility of real-time processing schemes using artificial neural networks (ANNs) is investigated. A rationale for digital neural nets is presented and a general processor architecture for control applications is illustrated. Research results on ANN structures for real-time applications are given. Research results on ANN algorithms for real-time control are also shown.

  1. 17 CFR 38.157 - Real-time market monitoring.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 17 Commodity and Securities Exchanges 1 2013-04-01 2013-04-01 false Real-time market monitoring... DESIGNATED CONTRACT MARKETS Compliance With Rules § 38.157 Real-time market monitoring. A designated contract market must conduct real-time market monitoring of all trading activity on its electronic...

  2. 17 CFR 38.157 - Real-time market monitoring.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 17 Commodity and Securities Exchanges 1 2014-04-01 2014-04-01 false Real-time market monitoring... DESIGNATED CONTRACT MARKETS Compliance With Rules § 38.157 Real-time market monitoring. A designated contract market must conduct real-time market monitoring of all trading activity on its electronic...

  3. Real-time CHAMP (RTC) infrared scene generation program

    NASA Astrophysics Data System (ADS)

    Crow, Dennis R.; Coker, Charles F.

    2001-08-01

    The Real-Time CHAMP (RTC) program is a computer simulation used to provide time varying high-fidelity infrared simulations of airborne vehicles and backgrounds in real- time. RTC is currently being utilized to provide real-time infrared imagery to support closed-loop digital and hardware-in-the-loop simulations. RTC computational algorithms take advantage of parametric databases created by its non real-time companion code (CHAMP--Composite Hardbody and Missile Plume) to allow accurate infrared imagery to be generated at real-time frame rates.

  4. Real-Time Coil Position Monitoring System for Biomagnetic Measurements

    NASA Astrophysics Data System (ADS)

    Oyama, Daisuke; Adachi, Yoshiaki; Higuchi, Masanori; Kawai, Jun; Kobayashi, Koichiro; Uehara, Gen

    In this paper, we propose a new method for monitoring the position of marker coils. The marker coil is used for indicating spatial relationship between subject's body and magnetic sensor arrays in biomagnetic measurements, such as magnetoencephalography (MEG) and magnetocardiography (MCG). We developed a real-time marker coil position monitoring system combined with a conventional MEG system. In order to achieve simultaneous measurement of MEG signals and marker signals, we separated their frequency bands. The frequency bands of flux-locked loop (FLL) circuits were separated into three parts by three integrators; low-band, mid-band, and high-band. The second and third bands were assigned for MEG signals and marker signals, respectively. This method can avoid the crosstalk of the marker signals to MEG signals. Marker signals were generated from five marker coils driven by five independent sinusoidal current generators. These signals were continuously measured by the high-band of FLL, and then the coils were localized by FFT processing and solving inverse problem. We succeeded in displaying the localized coil position on a PC monitor once per second in real-time.

  5. A high sensitivity real-time NVR monitor. [Nonvolatile Residue

    NASA Technical Reports Server (NTRS)

    Bowers, William D.; Chuan, R. L.

    1992-01-01

    The use of a temperature-controlled 200-MHz SAW resonator piezoelectric mass microbalance to monitor the mass of nonvolatile residue (NVR) deposited on its surface in real time is reported. The fundamental frequency of this device is mainly dependent on the configuration of the transducers and not on the thickness of the substrate. Therefore, higher operating frequencies can be achieved without reducing the thickness of the crystal. The real-time instrument was integrated onto a conventional stainless steel NVR plate and operated flawlessly over a 14-d period at Kennedy Space Center and successfully measured less than 1 ng/sq cm d NVR contamination. Contamination episodes detected by the instrument were correlated with scheduled activities on the test stand. Under the assumption of a baseline noise level of +/- 2 Hz, the absolute mass lower limit of detection would be 0.065 ng/sq cm. This would enable the detection of a daily NVR deposition rate of less than 0.1 ng/sq cm d.

  6. Acoustically trapped colloidal crystals that are reconfigurable in real time

    PubMed Central

    Caleap, Mihai; Drinkwater, Bruce W.

    2014-01-01

    Photonic and phononic crystals are metamaterials with repeating unit cells that result in internal resonances leading to a range of wave guiding and filtering properties and are opening up new applications such as hyperlenses and superabsorbers. Here we show the first, to our knowledge, 3D colloidal phononic crystal that is reconfigurable in real time and demonstrate its ability to rapidly alter its frequency filtering characteristics. Our reconfigurable material is assembled from microspheres in aqueous solution, trapped with acoustic radiation forces. The acoustic radiation force is governed by an energy landscape, determined by an applied high-amplitude acoustic standing wave field, in which particles move swiftly to energy minima. This creates a colloidal crystal of several milliliters in volume with spheres arranged in an orthorhombic lattice in which the acoustic wavelength is used to control the lattice spacing. Transmission acoustic spectroscopy shows that the new colloidal crystal behaves as a phononic metamaterial and exhibits clear band-pass and band-stop frequencies which are adjusted in real time. PMID:24706925

  7. Real-time accumulative computation motion detectors.

    PubMed

    Fernández-Caballero, Antonio; López, María Teresa; Castillo, José Carlos; Maldonado-Bascón, Saturnino

    2009-01-01

    The neurally inspired accumulative computation (AC) method and its application to motion detection have been introduced in the past years. This paper revisits the fact that many researchers have explored the relationship between neural networks and finite state machines. Indeed, finite state machines constitute the best characterized computational model, whereas artificial neural networks have become a very successful tool for modeling and problem solving. The article shows how to reach real-time performance after using a model described as a finite state machine. This paper introduces two steps towards that direction: (a) A simplification of the general AC method is performed by formally transforming it into a finite state machine. (b) A hardware implementation in FPGA of such a designed AC module, as well as an 8-AC motion detector, providing promising performance results. We also offer two case studies of the use of AC motion detectors in surveillance applications, namely infrared-based people segmentation and color-based people tracking, respectively. PMID:22303161

  8. Real-Time 3D Visualization

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Butler Hine, former director of the Intelligent Mechanism Group (IMG) at Ames Research Center, and five others partnered to start Fourth Planet, Inc., a visualization company that specializes in the intuitive visual representation of dynamic, real-time data over the Internet and Intranet. Over a five-year period, the then NASA researchers performed ten robotic field missions in harsh climes to mimic the end- to-end operations of automated vehicles trekking across another world under control from Earth. The core software technology for these missions was the Virtual Environment Vehicle Interface (VEVI). Fourth Planet has released VEVI4, the fourth generation of the VEVI software, and NetVision. VEVI4 is a cutting-edge computer graphics simulation and remote control applications tool. The NetVision package allows large companies to view and analyze in virtual 3D space such things as the health or performance of their computer network or locate a trouble spot on an electric power grid. Other products are forthcoming. Fourth Planet is currently part of the NASA/Ames Technology Commercialization Center, a business incubator for start-up companies.

  9. Real-Time Accumulative Computation Motion Detectors

    PubMed Central

    Fernández-Caballero, Antonio; López, María Teresa; Castillo, José Carlos; Maldonado-Bascón, Saturnino

    2009-01-01

    The neurally inspired accumulative computation (AC) method and its application to motion detection have been introduced in the past years. This paper revisits the fact that many researchers have explored the relationship between neural networks and finite state machines. Indeed, finite state machines constitute the best characterized computational model, whereas artificial neural networks have become a very successful tool for modeling and problem solving. The article shows how to reach real-time performance after using a model described as a finite state machine. This paper introduces two steps towards that direction: (a) A simplification of the general AC method is performed by formally transforming it into a finite state machine. (b) A hardware implementation in FPGA of such a designed AC module, as well as an 8-AC motion detector, providing promising performance results. We also offer two case studies of the use of AC motion detectors in surveillance applications, namely infrared-based people segmentation and color-based people tracking, respectively. PMID:22303161

  10. Real-time neural coding of memory.

    PubMed

    Tsien, Joe Z

    2007-01-01

    Recent identification of network-level functional coding units, termed neural cliques, in the hippocampus has allowed real-time patterns of memory traces to be mathematically described, intuitively visualized, and dynamically deciphered. Any given episodic event is represented and encoded by the activation of a set of neural clique assemblies that are organized in a categorical and hierarchical manner. This hierarchical feature-encoding pyramid is invariantly composed of the general feature-encoding clique at the bottom, sub-general feature-encoding cliques in the middle, and highly specific feature-encoding cliques at the top. This hierarchical and categorical organization of neural clique assemblies provides the network-level mechanism the capability of not only achieving vast storage capacity, but also generating commonalities from the individual behavioral episodes and converting them to the abstract concepts and generalized knowledge that are essential for intelligence and adaptive behaviors. Furthermore, activation patterns of the neural clique assemblies can be mathematically converted to strings of binary codes that would permit universal categorizations of the brain's internal representations across individuals and species. Such universal brain codes can also potentially facilitate the unprecedented brain-machine interface communications. PMID:17925242

  11. Real-time pricing's hidden surprise

    SciTech Connect

    Siddiqi, R.; Woodley, J.

    1994-03-01

    The electric utility industry in the United States and the rest of the world is in the midst of profound change, with various models of regulation and nonregulation being tested. The United States has opted for an incremental approach to changes in fundamental aspects of the industry. Other countries, most notably the United Kingdom, are in the process of deregulation. These different structures rely on and result in dramatically different markets. While market structures may differ, similar approaches to service designs are evolving. Specifically, service options based on pricing are proliferating, and customers are being given the opportunity to select from a menu of options. This is in marked contrast to the rigid tariff structures that presuppose monopoly status to achieve utility goals. Strong parallels may be drawn between the pool-pricing options and associated hedging mechanisms offered in England and Wales, and the two-part tariff-based real-time pricing (RTP) programs in the United States. The latter service design, which is undergoing experimentation at Georgia Power Co., and in pilot operation at Niagara Mohawk Power Corp., has been criticized as too complex and not reflecting a competitive pricing structure. However, the similarity between two-part tariff programs and pool-pricing services (offered in the U.K. to a significantly larger customer base, under greater competition) undercuts these criticisms.

  12. Real-time DIRCM system modeling

    NASA Astrophysics Data System (ADS)

    Petersson, Mikael

    2004-12-01

    Directed infrared countermeasures (DIRCM) play an increasingly important role in electronic warfare to counteract threats posed by infrared seekers. The usefulness and performance of such countermeasures depend, for example, on atmospheric conditions (attenuation and turbulence) and platform vibrations, causing pointing and tracking errors for the laser beam and reducing the power transferred to the seeker aperture. These problems make it interesting to simulate the performance of a DIRCM system in order to understand how easy or difficult it is to counteract an approaching threat and evaluate limiting factors in various situations. This paper describes a DIRCM model that has been developed, including atmospheric effects such as attenuation and turbulence as well as closed loop tracking algorithms, where the retro reflex of the laser is used for the pointing control of the beam. The DIRCM model is part of a large simulation framework (EWSim), which also incorporates several descriptions of different seekers (e.g. reticle, rosette, centroid, nutating cross) and models of robot dynamics. Effects of a jamming laser on a specific threat can be readily verified by simulations within this framework. The duel between missile and countermeasure is simulated in near real-time and visualized graphically in 3D. A typical simulation with a reticle seeker jammed by a modulated laser is included in the paper.

  13. Near Real Time Ship Detection Experiments

    NASA Astrophysics Data System (ADS)

    Brusch, S.; Lehner, S.; Schwarz, E.; Fritz, T.

    2010-04-01

    A new Near Real Time (NRT) ship detection processor SAINT (SAR AIS Integrated Toolbox) was developed in the framework of the ESA project MARISS. Data are received at DLRs ground segment DLR-BN (Neustrelitz, Germany). Results of the ship detection are available on ftp server within 30 min after the acquisition started. The detectability of ships on Synthetic Aperture Radar (SAR) ERS-2, ENVISAT ASAR and TerraSAR-X (TS-X) images is validated by coastal (live) AIS and space AIS. The monitoring areas chosen for surveillance are the North-, Baltic Sea, and Cape Town. The detectability in respect to environmental parameters like wind field, sea state, currents and changing coastlines due to tidal effects is investigated. In the South Atlantic a tracking experiment of the German research vessel Polarstern has been performed. Issues of piracy in particular in respect to ships hijacked at the Somali coast are discussed. Some examples using high resolution images from TerraSAR-X are given.

  14. Recommendations for real-time speech MRI.

    PubMed

    Lingala, Sajan Goud; Sutton, Brad P; Miquel, Marc E; Nayak, Krishna S

    2016-01-01

    Real-time magnetic resonance imaging (RT-MRI) is being increasingly used for speech and vocal production research studies. Several imaging protocols have emerged based on advances in RT-MRI acquisition, reconstruction, and audio-processing methods. This review summarizes the state-of-the-art, discusses technical considerations, and provides specific guidance for new groups entering this field. We provide recommendations for performing RT-MRI of the upper airway. This is a consensus statement stemming from the ISMRM-endorsed Speech MRI summit held in Los Angeles, February 2014. A major unmet need identified at the summit was the need for consensus on protocols that can be easily adapted by researchers equipped with conventional MRI systems. To this end, we provide a discussion of tradeoffs in RT-MRI in terms of acquisition requirements, a priori assumptions, artifacts, computational load, and performance for different speech tasks. We provide four recommended protocols and identify appropriate acquisition and reconstruction tools. We list pointers to open-source software that facilitate implementation. We conclude by discussing current open challenges in the methodological aspects of RT-MRI of speech. PMID:26174802

  15. Optimizing near real time accountability for reprocessing.

    SciTech Connect

    Cipiti, Benjamin B.

    2010-06-01

    Near Real Time Accountability (NRTA) of actinides at high precision in reprocessing plants has been a long sought-after goal in the safeguards community. Achieving this goal is hampered by the difficulty of making precision measurements in the reprocessing environment, equipment cost, and impact to plant operations. Thus the design of future reprocessing plants requires an optimization of different approaches. The Separations and Safeguards Performance Model, developed at Sandia National Laboratories, was used to evaluate a number of NRTA strategies in a UREX+ reprocessing plant. Strategies examined include the incorporation of additional actinide measurements of internal plant vessels, more use of process monitoring data, and the option of periodic draining of inventory to key tanks. Preliminary results show that the addition of measurement technologies can increase the overall measurement uncertainty due to additional error propagation, so care must be taken when designing an advanced system. Initial results also show that relying on a combination of different NRTA techniques will likely be the best option. The model provides a platform for integrating all the data. The modeling results for the different NRTA options under various material loss conditions will be presented.

  16. Real-time holographic camera system

    NASA Astrophysics Data System (ADS)

    Bazhenov, Mikhail Y.; Grabovski, Vitaly V.; Stolyarenko, Alexandr V.; Zahaykevich, George A.

    1997-04-01

    The holographic camera system for surface-relief hologram multiple reversible registration is presented. Photosensitive media is a single-layer photothermoplastic polymer on a glass substrate with conductive layer. This exclude a charges accumulation in the polymer volume and permits to realize an efficient enhancement of latent electrostatic image and its fast pulse heating development. The processes of charging, photogeneration, carriers transport, fast development and erasing, image enhancement were studied in detail and optimized. In order to improve some defects of photothermoplastic recording, originating from influences of circumstances and recording conditions, some new processes were developed: (1) fast charging with pulses corona in closed dielectric volume, (2) optoelectronic enhancement of electrostatic image, and (3) fast pulsed development with automatically controlled temperature rate. The dust-proof recording camera with built-in highvoltage power supply, thermo- and photosensors was designed to meet the needs of real-time or multiple- exposure interferometry, holographic training recording, holographic storage systems, correlation investigations and pattern recognition.

  17. Handheld real-time PCR device.

    PubMed

    Ahrberg, Christian D; Ilic, Bojan Robert; Manz, Andreas; Neužil, Pavel

    2016-02-01

    Here we report one of the smallest real-time polymerase chain reaction (PCR) systems to date with an approximate size of 100 mm × 60 mm × 33 mm. The system is an autonomous unit requiring an external 12 V power supply. Four simultaneous reactions are performed in the form of virtual reaction chambers (VRCs) where a ≈200 nL sample is covered with mineral oil and placed on a glass cover slip. Fast, 40 cycle amplification of an amplicon from the H7N9 gene was used to demonstrate the PCR performance. The standard curve slope was -3.02 ± 0.16 cycles at threshold per decade (mean ± standard deviation) corresponding to an amplification efficiency of 0.91 ± 0.05 per cycle (mean ± standard deviation). The PCR device was capable of detecting a single deoxyribonucleic acid (DNA) copy. These results further suggest that our handheld PCR device may have broad, technologically-relevant applications extending to rapid detection of infectious diseases in small clinics. PMID:26753557

  18. Towards real-time image quality assessment

    NASA Astrophysics Data System (ADS)

    Geary, Bobby; Grecos, Christos

    2011-03-01

    We introduce a real-time implementation and evaluation of a new fast accurate full reference based image quality metric. The popular general image quality metric known as the Structural Similarity Index Metric (SSIM) has been shown to be an effective, efficient and useful, finding many practical and theoretical applications. Recently the authors have proposed an enhanced version of the SSIM algorithm known as the Rotated Gaussian Discrimination Metric (RGDM). This approach uses a Gaussian-like discrimination function to evaluate local contrast and luminance. RGDM was inspired by an exploration of local statistical parameter variations in relation to variation of Mean Opinion Score (MOS) for a range of particular distortion types. In this paper we out-line the salient features of the derivation of RGDM and show how analyses of local statistics of distortion type necessitate variation in discrimination function width. Results on the LIVE image database show tight banding of RGDM metric value when plotted against mean opinion score indicating the usefulness of this metric. We then explore a number of strategies for algorithmic speed-up including the application of Integral Images for patch based computation optimisation, cost reduction for the evaluation of the discrimination function and general loop unrolling. We also employ fast Single Instruction Multiple Data (SIMD) intrinsics and explore data parallel decomposition on a multi-core Intel Processor.

  19. Real time inverse filter focusing through iterative time reversal.

    PubMed

    Montaldo, Gabriel; Tanter, Mickaël; Fink, Mathias

    2004-02-01

    In order to achieve an optimal focusing through heterogeneous media we need to build the inverse filter of the propagation operator. Time reversal is an easy and robust way to achieve such an inverse filter in nondissipative media. However, as soon as losses appear in the medium, time reversal is not equivalent to the inverse filter anymore. Consequently, it does not produce the optimal focusing and beam degradations may appear. In such cases, we showed in previous works that the optimal focusing can be recovered by using the so-called spatiotemporal inverse filter technique. This process requires the presence of a complete set of receivers inside the medium. It allows one to reach the optimal focusing even in extreme situations such as ultrasonic focusing through human skull or audible sound focusing in strongly reverberant rooms. But, this technique is time consuming and implied fastidious numerical calculations. In this paper we propose a new way to process this inverse filter focusing technique in real time and without any calculation. The new process is based on iterative time reversal process. Contrary to the classical inverse filter technique, this iteration does not require any computation and achieves the inverse filter in an experimental way using wave propagation instead of computational power. The convergence from time reversal to inverse filter during the iterative process is theoretically explained. Finally, the feasibility of this iterative technique is experimentally demonstrated for ultrasound applications. PMID:15000188

  20. Toward Real Time Neural Net Flight Controllers

    NASA Technical Reports Server (NTRS)

    Jorgensen, C. C.; Mah, R. W.; Ross, J.; Lu, Henry, Jr. (Technical Monitor)

    1994-01-01

    NASA Ames Research Center has an ongoing program in neural network control technology targeted toward real time flight demonstrations using a modified F-15 which permits direct inner loop control of actuators, rapid switching between alternative control designs, and substitutable processors. An important part of this program is the ACTIVE flight project which is examining the feasibility of using neural networks in the design, control, and system identification of new aircraft prototypes. This paper discusses two research applications initiated with this objective in mind: utilization of neural networks for wind tunnel aircraft model identification and rapid learning algorithms for on line reconfiguration and control. The first application involves the identification of aerodynamic flight characteristics from analysis of wind tunnel test data. This identification is important in the early stages of aircraft design because complete specification of control architecture's may not be possible even though concept models at varying scales are available for aerodynamic wind tunnel testing. Testing of this type is often a long and expensive process involving measurement of aircraft lift, drag, and moment of inertia at varying angles of attack and control surface configurations. This information in turn can be used in the design of the flight control systems by applying the derived lookup tables to generate piece wise linearized controllers. Thus, reduced costs in tunnel test times and the rapid transfer of wind tunnel insights into prototype controllers becomes an important factor in more efficient generation and testing of new flight systems. NASA Ames Research Center is successfully applying modular neural networks as one way of anticipating small scale aircraft model performances prior to testing, thus reducing the number of in tunnel test hours and potentially, the number of intermediate scaled models required for estimation of surface flow effects.

  1. Real time PV manufacturing diagnostic system

    SciTech Connect

    Kochergin, Vladimir; Crawford, Michael A.

    2015-09-01

    The main obstacle Photovoltaic (PV) industry is facing at present is the higher cost of PV energy compared to that of fossil energy. While solar cell efficiencies continue to make incremental gains these improvements are so far insufficient to drive PV costs down to match that of fossil energy. Improved in-line diagnostics however, has the potential to significantly increase the productivity and reduce cost by improving the yield of the process. On this Phase I/Phase II SBIR project MicroXact developed and demonstrated at CIGS pilot manufacturing line a high-throughput in-line PV manufacturing diagnostic system, which was verified to provide fast and accurate data on the spatial uniformity of thickness, an composition of the thin films comprising the solar cell as the solar cell is processed reel-to-reel. In Phase II project MicroXact developed a stand-alone system prototype and demonstrated the following technical characteristics: 1) ability of real time defect/composition inconsistency detection over 60cm wide web at web speeds up to 3m/minute; 2) Better than 1mm spatial resolution on 60cm wide web; 3) an average better than 20nm spectral resolution resulting in more than sufficient sensitivity to composition imperfections (copper-rich and copper-poor regions were detected). The system was verified to be high vacuum compatible. Phase II results completely validated both technical and economic feasibility of the proposed concept. MicroXact’s solution is an enabling technique for in-line PV manufacturing diagnostics to increase the productivity of PV manufacturing lines and reduce the cost of solar energy, thus reducing the US dependency on foreign oil while simultaneously reducing emission of greenhouse gasses.

  2. Real time monitoring of electroless nickel plating

    NASA Astrophysics Data System (ADS)

    Rains, Aaron E.; Kline, Ronald A.

    2013-01-01

    This work deals with the design and manufacturing of the heat and chemical resistant transducer case required for on-line immersion testing, experimental design, data acquisition and signal processing. Results are presented for several depositions with an accuracy of two ten-thousandths of an inch in coating thickness obtained. Monitoring the deposition rate of Electroless Nickel (EN) plating in-situ will provide measurement of the accurate dimensions of the component being plated, in real time. EN is used as for corrosion and wear protection for automotive an - Electroless Nickel (EN) plating is commonly used for corrosion and wear protection for automotive and aerospace components. It plates evenly and symmetrically, theoretically allowing the part to be plated to its final dimension. Currently the standard approach to monitoring the thickness of the deposited nickel is to remove the component from the plating bath and physically measure the part. This can lead to plating problems such as pitting, non-adhesion of the deposit and contamination of the plating solution. The goal of this research effort is to demonstrate that plating thickness can be rapidly and accurately measured using ultrasonic testing. Here a special housing is designed to allow immersion of the ultrasonic transducers directly into the plating bath. An FFT based signal processing algorithm was developed to resolve closely spaced echoes for precise thickness determination. The technique in this research effort was found to be capable of measuring plating thicknesses to within 0.0002 inches. It is expected that this approach will lead to cost savings in many EN plating operations.

  3. Real-Time Feature Tracking Using Homography

    NASA Technical Reports Server (NTRS)

    Clouse, Daniel S.; Cheng, Yang; Ansar, Adnan I.; Trotz, David C.; Padgett, Curtis W.

    2010-01-01

    This software finds feature point correspondences in sequences of images. It is designed for feature matching in aerial imagery. Feature matching is a fundamental step in a number of important image processing operations: calibrating the cameras in a camera array, stabilizing images in aerial movies, geo-registration of images, and generating high-fidelity surface maps from aerial movies. The method uses a Shi-Tomasi corner detector and normalized cross-correlation. This process is likely to result in the production of some mismatches. The feature set is cleaned up using the assumption that there is a large planar patch visible in both images. At high altitude, this assumption is often reasonable. A mathematical transformation, called an homography, is developed that allows us to predict the position in image 2 of any point on the plane in image 1. Any feature pair that is inconsistent with the homography is thrown out. The output of the process is a set of feature pairs, and the homography. The algorithms in this innovation are well known, but the new implementation improves the process in several ways. It runs in real-time at 2 Hz on 64-megapixel imagery. The new Shi-Tomasi corner detector tries to produce the requested number of features by automatically adjusting the minimum distance between found features. The homography-finding code now uses an implementation of the RANSAC algorithm that adjusts the number of iterations automatically to achieve a pre-set probability of missing a set of inliers. The new interface allows the caller to pass in a set of predetermined points in one of the images. This allows the ability to track the same set of points through multiple frames.

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

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

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

  5. Towards real-time regional earthquake simulation I: real-time moment tensor monitoring (RMT) for regional events in Taiwan

    NASA Astrophysics Data System (ADS)

    Lee, Shiann-Jong; Liang, Wen-Tzong; Cheng, Hui-Wen; Tu, Feng-Shan; Ma, Kuo-Fong; Tsuruoka, Hiroshi; Kawakatsu, Hitoshi; Huang, Bor-Shouh; Liu, Chun-Chi

    2014-01-01

    We have developed a real-time moment tensor monitoring system (RMT) which takes advantage of a grid-based moment tensor inversion technique and real-time broad-band seismic recordings to automatically monitor earthquake activities in the vicinity of Taiwan. The centroid moment tensor (CMT) inversion technique and a grid search scheme are applied to obtain the information of earthquake source parameters, including the event origin time, hypocentral location, moment magnitude and focal mechanism. All of these source parameters can be determined simultaneously within 117 s after the occurrence of an earthquake. The monitoring area involves the entire Taiwan Island and the offshore region, which covers the area of 119.3°E to 123.0°E and 21.0°N to 26.0°N, with a depth from 6 to 136 km. A 3-D grid system is implemented in the monitoring area with a uniform horizontal interval of 0.1° and a vertical interval of 10 km. The inversion procedure is based on a 1-D Green's function database calculated by the frequency-wavenumber (fk) method. We compare our results with the Central Weather Bureau (CWB) catalogue data for earthquakes occurred between 2010 and 2012. The average differences between event origin time and hypocentral location are less than 2 s and 10 km, respectively. The focal mechanisms determined by RMT are also comparable with the Broadband Array in Taiwan for Seismology (BATS) CMT solutions. These results indicate that the RMT system is realizable and efficient to monitor local seismic activities. In addition, the time needed to obtain all the point source parameters is reduced substantially compared to routine earthquake reports. By connecting RMT with a real-time online earthquake simulation (ROS) system, all the source parameters will be forwarded to the ROS to make the real-time earthquake simulation feasible. The RMT has operated offline (2010-2011) and online (since January 2012 to present) at the Institute of Earth Sciences (IES), Academia Sinica

  6. [EMD Time-Frequency Analysis of Raman Spectrum and NIR].

    PubMed

    Zhao, Xiao-yu; Fang, Yi-ming; Tan, Feng; Tong, Liang; Zhai, Zhe

    2016-02-01

    This paper analyzes the Raman spectrum and Near Infrared Spectrum (NIR) with time-frequency method. The empirical mode decomposition spectrum becomes intrinsic mode functions, which the proportion calculation reveals the Raman spectral energy is uniform distributed in each component, while the NIR's low order intrinsic mode functions only undertakes fewer primary spectroscopic effective information. Both the real spectrum and numerical experiments show that the empirical mode decomposition (EMD) regard Raman spectrum as the amplitude-modulated signal, which possessed with high frequency adsorption property; and EMD regards NIR as the frequency-modulated signal, which could be preferably realized high frequency narrow-band demodulation during first-order intrinsic mode functions. The first-order intrinsic mode functions Hilbert transform reveals that during the period of empirical mode decomposes Raman spectrum, modal aliasing happened. Through further analysis of corn leaf's NIR in time-frequency domain, after EMD, the first and second orders components of low energy are cut off, and reconstruct spectral signal by using the remaining intrinsic mode functions, the root-mean-square error is 1.001 1, and the correlation coefficient is 0.981 3, both of these two indexes indicated higher accuracy in re-construction; the decomposition trend term indicates the absorbency is ascending along with the decreasing to wave length in the near-infrared light wave band; and the Hilbert transform of characteristic modal component displays, 657 cm⁻¹ is the specific frequency by the corn leaf stress spectrum, which could be regarded as characteristic frequency for identification. PMID:27209743

  7. A Method for Ventricular Late Potentials Detection Using Time-Frequency Representation and Wavelet Denoising

    PubMed Central

    Gadaleta, Matteo; Giorgio, Agostino

    2012-01-01

    This study proposes a method for ventricular late potentials (VLPs) detection using time-frequency representation and wavelet denoising in high-resolution electrocardiography (HRECG). The analysis is performed both with the signal averaged electrocardiography (SAECG) and in real time. A comparison between the temporal and the time-frequency analysis is also reported. In the first analysis the standard parameters QRSd, LAS40, and RMS40 were used; in the second normalized energy in time-frequency domain was calculated. The algorithm was tested adding artificial VLPs to real ECGs. PMID:22957271

  8. A miniature real-time volumetric ultrasound imaging system

    NASA Astrophysics Data System (ADS)

    Wygant, Ira O.; Yeh, David T.; Zhuang, Xuefeng; Nikoozadeh, Amin; Oralkan, Omer; Ergun, Arif S.; Karaman, Mustafa; Khuri-Yakub, Butrus T.

    2005-04-01

    Progress made in the development of a miniature real-time volumetric ultrasound imaging system is presented. This system is targeted for use in a 5-mm endoscopic channel and will provide real-time, 30-mm deep, volumetric images. It is being developed as a clinically useful device, to demonstrate a means of integrating the front-end electronics with the transducer array, and to demonstrate the advantages of the capacitive micromachined ultrasonic transducer (CMUT) technology for medical imaging. Presented here is the progress made towards the initial implementation of this system, which is based on a two-dimensional, 16x16 CMUT array. Each CMUT element is 250 um by 250 um and has a 5 MHz center frequency. The elements are connected to bond pads on the back side of the array with 400-um long through-wafer interconnects. The transducer array is flip-chip bonded to a custom-designed integrated circuit that comprises the front-end electronics. The result is that each transducer element is connected to a dedicated pulser and low-noise preamplifier. The pulser generates 25-V, 100-ns wide, unipolar pulses. The preamplifier has an approximate transimpedance gain of 500 kOhm and 3-dB bandwidth of 10 MHz. In the first implementation of the system, one element at a time can be selected for transmit and receive and thus synthetic aperture images can be generated. In future implementations, 16 channels will be active at a given time. These channels will connect to an FPGA-based data acquisition system for real-time image reconstruction.

  9. Real time UAV autonomy through offline calculations

    NASA Astrophysics Data System (ADS)

    Jung, Sunghun

    . Once one or several targets are detected, UAVs near the target are manipulated to approach to the target. If the number of detected targets is more than one, UAVs are evenly grouped to track targets. After a specific period of time, UAVs hand off and continue their original tasks. Thirdly, Emergency algorithm is generated to avoid losses of UAVs when UAVs have system failures. If one UAV is out of fuel or control during the mission, the Emergency algorithm brings the malfunctioning UAV to the point of departure and let the rest UAVs to continue an aerial reconnaissance. An UAV which finishes its task the earliest will continue to search a region which the failed UAV is supposed to search. In addition, Emergency algorithm prevents UAVs colliding into each other by using emergency altitude. Overall, the framework developed here facilitates the solution of several mission planning problems. The robustness built into our discretization of space and time permits feedback corrections on real-time to vehicle trajectories. The library of off-line solutions proposed and developed here minimizes computational overhead during operations.

  10. Postural tachycardia syndrome: time frequency mapping.

    PubMed

    Novak, V; Novak, P; Opfer-Gehrking, T L; Low, P A

    1996-12-14

    Orthostatic tachycardia is common but its specificity remains uncertain. Our preliminary work suggested that using autonomic function testing in conjunction with time-frequency mapping (TFM), it might be possible to characterize a subset of the postural tachycardia syndrome (POTS), that is due to a restricted autonomic neuropathy. We describe 20 patients (17 women and 3 men, aged 14-43 years) with florid POTS and 20 controls (14 women and 6 men, aged 20-41 years). Autonomic failure was quantified by its distribution (cardiovagal, adrenergic and sudomotor) and severity, a symptom profile was generated, and spectral indices, based on modified Wigner distribution during rest and head-up tilt (80 degrees) were evaluated. During tilt-up POTS patients differed from controls by an excessive heart rate (> 130 bpm) (P < 0.001), and higher diastolic pressure (P < 0.01). During rest, cardiovagal oscillations (at respiratory frequencies [RF]) and slow rhythms at nonrespiratory frequencies (NONRF) (from 0.01 to 0.07 Hz) in R-R intervals (RRI) (P < 0.01) were reduced. Both RF and NONRF rhythms in RRI were further blunted with tilt-up (P < 0.001). Slow adrenergic vasomotor rhythms in blood pressure (BP) (approximately 0.07 Hz) surged with tilt-up and returned to normal levels afterwards. The index of sympatho-vagal balance (NONRF-Systolic BP (SBP)/RF-RRI) was dramatically increased in POTS (P < 0.001). Distal postganglionic sudomotor failure was observed, and impairment of the BP responses to the Valsalva maneuver (phase II) suggested peripheral adrenergic dysfunction. Persistent orthostatic dizziness, tiredness, gastrointestinal symptoms and palpitations were common in POTS patients. It is possible to identify a subset of POTS patients who have a length-dependent autonomic neuropathy, affecting the peripheral adrenergic and cardiovagal fibers, with relative preservation of cardiac adrenergic fibers. PMID:8988490

  11. Postural tachycardia syndrome: time frequency mapping

    NASA Technical Reports Server (NTRS)

    Novak, V.; Novak, P.; Opfer-Gehrking, T. L.; Low, P. A.

    1996-01-01

    Orthostatic tachycardia is common but its specificity remains uncertain. Our preliminary work suggested that using autonomic function testing in conjunction with time-frequency mapping (TFM), it might be possible to characterize a subset of the postural tachycardia syndrome (POTS), that is due to a restricted autonomic neuropathy. We describe 20 patients (17 women and 3 men, aged 14-43 years) with florid POTS and 20 controls (14 women and 6 men, aged 20-41 years). Autonomic failure was quantified by its distribution (cardiovagal, adrenergic and sudomotor) and severity, a symptom profile was generated, and spectral indices, based on modified Wigner distribution during rest and head-up tilt (80 degrees) were evaluated. During tilt-up POTS patients differed from controls by an excessive heart rate (> 130 bpm) (P < 0.001), and higher diastolic pressure (P < 0.01). During rest, cardiovagal oscillations (at respiratory frequencies [RF]) and slow rhythms at nonrespiratory frequencies (NONRF) (from 0.01 to 0.07 Hz) in R-R intervals (RRI) (P < 0.01) were reduced. Both RF and NONRF rhythms in RRI were further blunted with tilt-up (P < 0.001). Slow adrenergic vasomotor rhythms in blood pressure (BP) (approximately 0.07 Hz) surged with tilt-up and returned to normal levels afterwards. The index of sympatho-vagal balance (NONRF-Systolic BP (SBP)/RF-RRI) was dramatically increased in POTS (P < 0.001). Distal postganglionic sudomotor failure was observed, and impairment of the BP responses to the Valsalva maneuver (phase II) suggested peripheral adrenergic dysfunction. Persistent orthostatic dizziness, tiredness, gastrointestinal symptoms and palpitations were common in POTS patients. It is possible to identify a subset of POTS patients who have a length-dependent autonomic neuropathy, affecting the peripheral adrenergic and cardiovagal fibers, with relative preservation of cardiac adrenergic fibers.

  12. Binary Time Series Modeling with Application to Adhesion Frequency Experiments

    PubMed Central

    Hung, Ying; Zarnitsyna, Veronika; Zhang, Yan; Zhu, Cheng; Wu, C. F. Jeff

    2011-01-01

    Repeated adhesion frequency assay is the only published method for measuring the kinetic rates of cell adhesion. Cell adhesion plays an important role in many physiological and pathological processes. Traditional analysis of adhesion frequency experiments assumes that the adhesion test cycles are independent Bernoulli trials. This assumption can often be violated in practice. Motivated by the analysis of repeated adhesion tests, a binary time series model incorporating random effects is developed in this paper. A goodness-of-fit statistic is introduced to assess the adequacy of distribution assumptions on the dependent binary data with random effects. The asymptotic distribution of the goodness-of-fit statistic is derived and its finite-sample performance is examined via a simulation study. Application of the proposed methodology to real data from a T-cell experiment reveals some interesting information, including the dependency between repeated adhesion tests. PMID:22180690

  13. Instrumentation development for real time brainwave monitoring.

    SciTech Connect

    Anderson, Lawrence Frederick; Clough, Benjamin W.

    2005-12-01

    The human brain functions through a chemically-induced biological process which operates in a manner similar to electrical systems. The signal resulting from this biochemical process can actually be monitored and read using tools and having patterns similar to those found in electrical and electronics engineering. The primary signature of this electrical activity is the ''brain wave'', which looks remarkably similar to the output of many electrical systems. Likewise, the device currently used in medical arenas to read brain electrical activity is the electroencephalogram (EEG) which is synonymous with a multi-channel oscilloscope reading. Brain wave readings and recordings for medical purposes are traditionally taken in clinical settings such as hospitals, laboratories or diagnostic clinics. The signal is captured via externally applied scalp electrodes using semi-viscous gel to reduce impedance. The signal will be in the 10 to 100 microvolt range. In other instances, where surgeons are attempting to isolate particular types of minute brain signals, the electrodes may actually be temporarily implanted in the brain during a preliminary procedure. The current configurations of equipment required for EEGs involve large recording instruments, many electrodes, wires, and large amounts of hard disk space devoted to storing large files of brain wave data which are then eventually analyzed for patterns of concern. Advances in sensors, signal processing, data storage and microelectronics over the last decade would seem to have paved the way for the realization of devices capable of ''real time'' external monitoring, and possible assessment, of brain activity. A myriad of applications for such a capability are likewise presenting themselves, including the ability to assess brain functioning, level of functioning and malfunctioning. Our plan is to develop the sensors, signal processing, and portable instrumentation package which could capture, analyze, and communicate

  14. Real Time Seismic Loss Estimation in Italy

    NASA Astrophysics Data System (ADS)

    Goretti, A.; Sabetta, F.

    2009-04-01

    By more than 15 years the Seismic Risk Office is able to perform a real-time evaluation of the earthquake potential loss in any part of Italy. Once the epicentre and the magnitude of the earthquake are made available by the National Institute for Geophysiscs and Volca-nology, the model, based on the Italian Geographic Information Sys-tems, is able to evaluate the extent of the damaged area and the consequences on the built environment. In recent years the model has been significantly improved with new methodologies able to conditioning the uncertainties using observa-tions coming from the fields during the first days after the event. However it is reputed that the main challenges in loss analysis are related to the input data, more than to methodologies. Unlike the ur-ban scenario, where the missing data can be collected with enough accuracy, the country-wise analysis requires the use of existing data bases, often collected for other purposed than seismic scenario evaluation, and hence in some way lacking of completeness and homogeneity. Soil properties, building inventory and population dis-tribution are the main input data that are to be known in any site of the whole Italian territory. To this end the National Census on Popu-lation and Dwellings has provided information on the residential building types and the population that lives in that building types. The critical buildings, such as Hospital, Fire Brigade Stations, Schools, are not included in the inventory, since the national plan for seismic risk assessment of critical buildings is still under way. The choice of a proper soil motion parameter, its attenuation with distance and the building type fragility are important ingredients of the model as well. The presentation will focus on the above mentioned issues, highlight-ing the different data sets used and their accuracy, and comparing the model, input data and results when geographical areas with dif-ferent extent are considered: from the urban scenarios

  15. Real Time Wide Area Radiation Surveillance System

    NASA Astrophysics Data System (ADS)

    Biafore, M.

    2012-04-01

    We present the REWARD project, financed within the FP7 programme, theme SEC-2011.1.5-1 (Development of detection capabilities of difficult to detect radioactive sources and nuclear materials - Capability Project). Within this project, we propose a novel mobile system for real time, wide area radiation surveillance. The system is based on the integration of new miniaturized solid-state radiation sensors: a CdZnTe detector for gamma radiation and a high efficiency neutron detector based on novel silicon technologies. The sensing unit will include a wireless communication interface to send the data remotely to a monitoring base station which also uses a GPS system to calculate the position of the tag. The system will also incorporate middleware and high level software to provide web-service interfaces for the exchange of information, and that will offer top level functionalities as management of users, mobile tags and environment data and alarms, database storage and management and a web-based graphical user interface. Effort will be spent to ensure that the software is modular and re-usable across as many architectural levels as possible. Finally, an expert system will continuously analyze the information from the radiation sensor and correlate it with historical data from the tag location in order to generate an alarm when an abnormal situation is detected. The system will be useful for many different scenarios, including such lost radioactive sources and radioactive contamination. It will be possible to deploy in emergency units and in general in any type of mobile or static equipment. The sensing units will be highly portable thanks to their low size and low energy consumption. The complete system will be scalable in terms of complexity and cost and will offer very high precision on both the measurement and the location of the radiation. The modularity and flexibility of the system will allow for a realistic introduction to the market. Authorities may start with a

  16. Real-time Forensic Disaster Analysis

    NASA Astrophysics Data System (ADS)

    Wenzel, F.; Daniell, J.; Khazai, B.; Mühr, B.; Kunz-Plapp, T.; Markus, M.; Vervaeck, A.

    2012-04-01

    The Center for Disaster Management and Risk Reduction Technology (CEDIM, www.cedim.de) - an interdisciplinary research center founded by the German Research Centre for Geoscience (GFZ) and Karlsruhe Institute of Technology (KIT) - has embarked on a new style of disaster research known as Forensic Disaster Analysis. The notion has been coined by the Integrated Research on Disaster Risk initiative (IRDR, www.irdrinternational.org) launched by ICSU in 2010. It has been defined as an approach to studying natural disasters that aims at uncovering the root causes of disasters through in-depth investigations that go beyond the reconnaissance reports and case studies typically conducted after disasters. In adopting this comprehensive understanding of disasters CEDIM adds a real-time component to the assessment and evaluation process. By comprehensive we mean that most if not all relevant aspects of disasters are considered and jointly analysed. This includes the impact (human, economy, and infrastructure), comparisons with recent historic events, social vulnerability, reconstruction and long-term impacts on livelihood issues. The forensic disaster analysis research mode is thus best characterized as "event-based research" through systematic investigation of critical issues arising after a disaster across various inter-related areas. The forensic approach requires (a) availability of global data bases regarding previous earthquake losses, socio-economic parameters, building stock information, etc.; (b) leveraging platforms such as the EERI clearing house, relief-web, and the many sources of local and international sources where information is organized; and (c) rapid access to critical information (e.g., crowd sourcing techniques) to improve our understanding of the complex dynamics of disasters. The main scientific questions being addressed are: What are critical factors that control loss of life, of infrastructure, and for economy? What are the critical interactions

  17. A real-time transmission line model for a digital TNA

    SciTech Connect

    Wang, X.; Woodford, D.A.; Kuffel, R.; Wierckx, R.

    1996-04-01

    This paper presents a validation of a real-time digital simulation of a transmission line model with frequency dependent parameters. The real-time transmission line model is based on Marti`s time domain formulation which is adopted in the EMTP and EMTDC programs. Improvements to speed up the calculation are made in order to realize electromagnetic transient simulation in real-time by parallel processing using two digital signal processors (DSP`s) for each line. 41 {micro}s and 71 {micro}s time steps are readily achieved in real time with the new line model for three phase and double circuit (6 conductors) transmission lines respectively. The new line model is now installed in a Real-Time Digital Simulator (RTDS). Field test results are presented in this paper for validating the new line model.

  18. A class of kernel based real-time elastography algorithms.

    PubMed

    Kibria, Md Golam; Hasan, Md Kamrul

    2015-08-01

    In this paper, a novel real-time kernel-based and gradient-based Phase Root Seeking (PRS) algorithm for ultrasound elastography is proposed. The signal-to-noise ratio of the strain image resulting from this method is improved by minimizing the cross-correlation discrepancy between the pre- and post-compression radio frequency signals with an adaptive temporal stretching method and employing built-in smoothing through an exponentially weighted neighborhood kernel in the displacement calculation. Unlike conventional PRS algorithms, displacement due to tissue compression is estimated from the root of the weighted average of the zero-lag cross-correlation phases of the pair of corresponding analytic pre- and post-compression windows in the neighborhood kernel. In addition to the proposed one, the other time- and frequency-domain elastography algorithms (Ara et al., 2013; Hussain et al., 2012; Hasan et al., 2012) proposed by our group are also implemented in real-time using Java where the computations are serially executed or parallely executed in multiple processors with efficient memory management. Simulation results using finite element modeling simulation phantom show that the proposed method significantly improves the strain image quality in terms of elastographic signal-to-noise ratio (SNRe), elastographic contrast-to-noise ratio (CNRe) and mean structural similarity (MSSIM) for strains as high as 4% as compared to other reported techniques in the literature. Strain images obtained for the experimental phantom as well as in vivo breast data of malignant or benign masses also show the efficacy of our proposed method over the other reported techniques in the literature. PMID:25929595

  19. Fast Simulation of Tsunamis in Real Time

    NASA Astrophysics Data System (ADS)

    Fryer, G. J.; Wang, D.; Becker, N. C.; Weinstein, S. A.; Walsh, D.

    2011-12-01

    The U.S. Tsunami Warning Centers primarily base their wave height forecasts on precomputed tsunami scenarios, such as the SIFT model (Standby Inundation Forecasting of Tsunamis) developed by NOAA's Center for Tsunami Research. In SIFT, tsunami simulations for about 1600 individual earthquake sources, each 100x50 km, define shallow subduction worldwide. These simulations are stored in a database and combined linearly to make up the tsunami from any great earthquake. Precomputation is necessary because the nonlinear shallow-water wave equations are too time consuming to compute during an event. While such scenario-based models are valuable, they tacitly assume all energy in a tsunami comes from thrust at the décollement. The thrust assumption is often violated (e.g., 1933 Sanriku, 2007 Kurils, 2009 Samoa), while a significant number of tsunamigenic earthquakes are completely unrelated to subduction (e.g., 1812 Santa Barbara, 1939 Accra, 1975 Kalapana). Finally, parts of some subduction zones are so poorly defined that precomputations may be of little value (e.g., 1762 Arakan, 1755 Lisbon). For all such sources, a fast means of estimating tsunami size is essential. At the Pacific Tsunami Warning Center, we have been using our model RIFT (Real-time Inundation Forecasting of Tsunamis) experimentally for two years. RIFT is fast by design: it solves only the linearized form of the equations. At 4 arc-minutes resolution calculations for the entire Pacific take just a few minutes on an 8-processor Linux box. Part of the rationale for developing RIFT was earthquakes of M 7.8 or smaller, which approach the lower limit of the more complex SIFT's abilities. For such events we currently issue a fixed warning to areas within 1,000 km of the source, which typically means a lot of over-warning. With sources defined by W-phase CMTs, exhaustive comparison with runup data shows that we can reduce the warning area significantly. Even before CMTs are available, we routinely run models

  20. Adaptive real-time dual-comb spectroscopy.

    PubMed

    Ideguchi, Takuro; Poisson, Antonin; Guelachvili, Guy; Picqué, Nathalie; Hänsch, Theodor W

    2014-01-01

    The spectrum of a laser frequency comb consists of several hundred thousand equally spaced lines over a broad spectral bandwidth. Such frequency combs have revolutionized optical frequency metrology and they now hold much promise for significant advances in a growing number of applications including molecular spectroscopy. Despite an intriguing potential for the measurement of molecular spectra spanning tens of nanometres within tens of microseconds at Doppler-limited resolution, the development of dual-comb spectroscopy is hindered by the demanding stability requirements of the laser combs. Here we overcome this difficulty and experimentally demonstrate a concept of real-time dual-comb spectroscopy, which compensates for laser instabilities by electronic signal processing. It only uses free-running mode-locked lasers without any phase-lock electronics. We record spectra spanning the full bandwidth of near-infrared fibre lasers with Doppler-limited line profiles highly suitable for measurements of concentrations or line intensities. Our new technique of adaptive dual-comb spectroscopy offers a powerful transdisciplinary instrument for analytical sciences. PMID:24572636

  1. Adaptive real-time dual-comb spectroscopy

    PubMed Central

    Ideguchi, Takuro; Poisson, Antonin; Guelachvili, Guy; Picqué, Nathalie; Hänsch, Theodor W.

    2014-01-01

    The spectrum of a laser frequency comb consists of several hundred thousand equally spaced lines over a broad spectral bandwidth. Such frequency combs have revolutionized optical frequency metrology and they now hold much promise for significant advances in a growing number of applications including molecular spectroscopy. Despite an intriguing potential for the measurement of molecular spectra spanning tens of nanometres within tens of microseconds at Doppler-limited resolution, the development of dual-comb spectroscopy is hindered by the demanding stability requirements of the laser combs. Here we overcome this difficulty and experimentally demonstrate a concept of real-time dual-comb spectroscopy, which compensates for laser instabilities by electronic signal processing. It only uses free-running mode-locked lasers without any phase-lock electronics. We record spectra spanning the full bandwidth of near-infrared fibre lasers with Doppler-limited line profiles highly suitable for measurements of concentrations or line intensities. Our new technique of adaptive dual-comb spectroscopy offers a powerful transdisciplinary instrument for analytical sciences. PMID:24572636

  2. Adaptive real-time dual-comb spectroscopy

    NASA Astrophysics Data System (ADS)

    Ideguchi, Takuro; Poisson, Antonin; Guelachvili, Guy; Picqué, Nathalie; Hänsch, Theodor W.

    2014-02-01

    The spectrum of a laser frequency comb consists of several hundred thousand equally spaced lines over a broad spectral bandwidth. Such frequency combs have revolutionized optical frequency metrology and they now hold much promise for significant advances in a growing number of applications including molecular spectroscopy. Despite an intriguing potential for the measurement of molecular spectra spanning tens of nanometres within tens of microseconds at Doppler-limited resolution, the development of dual-comb spectroscopy is hindered by the demanding stability requirements of the laser combs. Here we overcome this difficulty and experimentally demonstrate a concept of real-time dual-comb spectroscopy, which compensates for laser instabilities by electronic signal processing. It only uses free-running mode-locked lasers without any phase-lock electronics. We record spectra spanning the full bandwidth of near-infrared fibre lasers with Doppler-limited line profiles highly suitable for measurements of concentrations or line intensities. Our new technique of adaptive dual-comb spectroscopy offers a powerful transdisciplinary instrument for analytical sciences.

  3. Easy and hard testbeds for real-time search algorithms

    SciTech Connect

    Koenig, S.; Simmons, R.G.

    1996-12-31

    Although researchers have studied which factors influence the behavior of traditional search algorithms, currently not much is known about how domain properties influence the performance of real-time search algorithms. In this paper we demonstrate, both theoretically and experimentally, that Eulerian state spaces (a super set of undirected state spaces) are very easy for some existing real-time search algorithms to solve: even real-time search algorithms that can be intractable, in general, are efficient for Eulerian state spaces. Because traditional real-time search testbeds (such as the eight puzzle and gridworlds) are Eulerian, they cannot be used to distinguish between efficient and inefficient real-time search algorithms. It follows that one has to use non-Eulerian domains to demonstrate the general superiority of a given algorithm. To this end, we present two classes of hard-to-search state spaces and demonstrate the performance of various real-time search algorithms on them.

  4. Automatic parquet block sorting using real-time spectral classification

    NASA Astrophysics Data System (ADS)

    Astrom, Anders; Astrand, Erik; Johansson, Magnus

    1999-03-01

    This paper presents a real-time spectral classification system based on the PGP spectrograph and a smart image sensor. The PGP is a spectrograph which extracts the spectral information from a scene and projects the information on an image sensor, which is a method often referred to as Imaging Spectroscopy. The classification is based on linear models and categorizes a number of pixels along a line. Previous systems adopting this method have used standard sensors, which often resulted in poor performance. The new system, however, is based on a patented near-sensor classification method, which exploits analogue features on the smart image sensor. The method reduces the enormous amount of data to be processed at an early stage, thus making true real-time spectral classification possible. The system has been evaluated on hardwood parquet boards showing very good results. The color defects considered in the experiments were blue stain, white sapwood, yellow decay and red decay. In addition to these four defect classes, a reference class was used to indicate correct surface color. The system calculates a statistical measure for each parquet block, giving the pixel defect percentage. The patented method makes it possible to run at very high speeds with a high spectral discrimination ability. Using a powerful illuminator, the system can run with a line frequency exceeding 2000 line/s. This opens up the possibility to maintain high production speed and still measure with good resolution.

  5. A real time neural net estimator of fatigue life

    NASA Technical Reports Server (NTRS)

    Troudet, T.; Merrill, W.

    1990-01-01

    A neural network architecture is proposed to estimate, in real-time, the fatigue life of mechanical components, as part of the intelligent Control System for Reusable Rocket Engines. Arbitrary component loading values were used as input to train a two hidden-layer feedforward neural net to estimate component fatigue damage. The ability of the net to learn, based on a local strain approach, the mapping between load sequence and fatigue damage has been demonstrated for a uniaxial specimen. Because of its demonstrated performance, the neural computation may be extended to complex cases where the loads are biaxial or triaxial, and the geometry of the component is complex (e.g., turbopumps blades). The generality of the approach is such that load/damage mappings can be directly extracted from experimental data without requiring any knowledge of the stress/strain profile of the component. In addition, the parallel network architecture allows real-time life calculations even for high-frequency vibrations. Owing to its distributed nature, the neural implementation will be robust and reliable, enabling its use in hostile environments such as rocket engines.

  6. A real time neural net estimator of fatigue life

    NASA Technical Reports Server (NTRS)

    Troudet, T.; Merrill, W.

    1990-01-01

    A neural net architecture is proposed to estimate, in real-time, the fatigue life of mechanical components, as part of the Intelligent Control System for Reusable Rocket Engines. Arbitrary component loading values were used as input to train a two hidden-layer feedforward neural net to estimate component fatigue damage. The ability of the net to learn, based on a local strain approach, the mapping between load sequence and fatigue damage has been demonstrated for a uniaxial specimen. Because of its demonstrated performance, the neural computation may be extended to complex cases where the loads are biaxial or triaxial, and the geometry of the component is complex (e.g., turbopump blades). The generality of the approach is such that load/damage mappings can be directly extracted from experimental data without requiring any knowledge of the stress/strain profile of the component. In addition, the parallel network architecture allows real-time life calculations even for high frequency vibrations. Owing to its distributed nature, the neural implementation will be robust and reliable, enabling its use in hostile environments such as rocket engines. This neural net estimator of fatigue life is seen as the enabling technology to achieve component life prognosis, and therefore would be an important part of life extending control for reusable rocket engines.

  7. Real Time Flux Control in PM Motors

    SciTech Connect

    Otaduy, P.J.

    2005-09-27

    Significant research at the Oak Ridge National Laboratory (ORNL) Power Electronics and Electric Machinery Research Center (PEEMRC) is being conducted to develop ways to increase (1) torque, (2) speed range, and (3) efficiency of traction electric motors for hybrid electric vehicles (HEV) within existing current and voltage bounds. Current is limited by the inverter semiconductor devices' capability and voltage is limited by the stator wire insulation's ability to withstand the maximum back-electromotive force (emf), which occurs at the upper end of the speed range. One research track has been to explore ways to control the path and magnitude of magnetic flux while the motor is operating. The phrase, real time flux control (RTFC), refers to this mode of operation in which system parameters are changed while the motor is operating to improve its performance and speed range. RTFC has potential to meet an increased torque demand by introducing additional flux through the main air gap from an external source. It can augment the speed range by diverting flux away from the main air gap to reduce back-emf at high speeds. Conventional RTFC technology is known as vector control [1]. Vector control decomposes the stator current into two components; one that produces torque and a second that opposes (weakens) the magnetic field generated by the rotor, thereby requiring more overall stator current and reducing the efficiency. Efficiency can be improved by selecting a RTFC method that reduces the back-emf without increasing the average current. This favors methods that use pulse currents or very low currents to achieve field weakening. Foremost in ORNL's effort to develop flux control is the work of J. S. Hsu. Early research [2,3] introduced direct control of air-gap flux in permanent magnet (PM) machines and demonstrated it with a flux-controlled generator. The configuration eliminates the problem of demagnetization because it diverts all the flux from the magnets instead of

  8. Cloud-ECG for real time ECG monitoring and analysis.

    PubMed

    Xia, Henian; Asif, Irfan; Zhao, Xiaopeng

    2013-06-01

    Recent advances in mobile technology and cloud computing have inspired numerous designs of cloud-based health care services and devices. Within the cloud system, medical data can be collected and transmitted automatically to medical professionals from anywhere and feedback can be returned to patients through the network. In this article, we developed a cloud-based system for clients with mobile devices or web browsers. Specially, we aim to address the issues regarding the usefulness of the ECG data collected from patients themselves. Algorithms for ECG enhancement, ECG quality evaluation and ECG parameters extraction were implemented in the system. The system was demonstrated by a use case, in which ECG data was uploaded to the web server from a mobile phone at a certain frequency and analysis was performed in real time using the server. The system has been proven to be functional, accurate and efficient. PMID:23261079

  9. Real-time and postprocessing holographic effects in dichromated pullulan.

    PubMed

    Savić, Svetlana; Pantelić, Dejan; Jakovijević, Dragica

    2002-08-01

    Experimental results concerning both real-time and postprocessing (after-development) behavior of a novel photosensitive material, dichromate-sensitized pullulan (DCP), are investigated. The exposure mechanism and possibilities for controlling holographic grating properties are discussed. We have shown that it is possible to maximize the diffraction efficiency of interference gratings after development by controlling diffraction efficiency in real time. Stronger real-time effects of DCP compared with those of dichromated gelatin are achieved. PMID:12153075

  10. Severe storms measurement system real time data processing and displays

    NASA Technical Reports Server (NTRS)

    Jeffreys, H. B.

    1980-01-01

    The objectives of the system are to provide the system operator with real time system performance check and to provide data recording of all SSMS data. Meteorologists are provided with real time indication of meteorological data measurements including aid for directing flight profiles in real time and aid for directing SSMS operations. A day-to-day feedback is provided to meteorologists, system operators, and flight crews for flight planning on subsequent flight tests days.

  11. Real-Time MENTAT programming language and architecture

    NASA Technical Reports Server (NTRS)

    Grimshaw, Andrew S.; Silberman, Ami; Liu, Jane W. S.

    1989-01-01

    Real-time MENTAT, a programming environment designed to simplify the task of programming real-time applications in distributed and parallel environments, is described. It is based on the same data-driven computation model and object-oriented programming paradigm as MENTAT. It provides an easy-to-use mechanism to exploit parallelism, language constructs for the expression and enforcement of timing constraints, and run-time support for scheduling and exciting real-time programs. The real-time MENTAT programming language is an extended C++. The extensions are added to facilitate automatic detection of data flow and generation of data flow graphs, to express the timing constraints of individual granules of computation, and to provide scheduling directives for the runtime system. A high-level view of the real-time MENTAT system architecture and programming language constructs is provided.

  12. Methods for real-time speech processing on Unix

    SciTech Connect

    Romberger, A.

    1982-01-01

    The author discusses computer programming done at the University of California, Berkeley, in support of research work in the area of speech analysis and synthesis. The purpose of this programming is to set up a system for doing real-time speech sampling using the Unix operating system. Two alternative approaches to real time work on Unix are discussed. The first approach is to do the real-time input/output on a secondary (satellite) machine that is not running Unix. The second approach is to do the real-time input/output on the main machine with the aid of special hardware.

  13. Hybrid integrated optic modules for real-time signal processing

    NASA Technical Reports Server (NTRS)

    Tsai, C. S.

    1984-01-01

    The most recent progress on four relatively new hybrid integrated optic device modules in LiNbO3 waveguides and one in YIG/GGG waveguide that are currently being studied are discussed. The five hybrid modules include a time-integrating acoustooptic correlator, a channel waveguide acoustooptic frequency shifter/modulator, an electrooptic channel waveguide total internal reflection moculator/switch, an electrooptic analog-to-digital converter using a Fabry-Perot modulator array, and a noncollinear magnetooptic modulator using magnetostatic surface waves. All of these devices possess the desirable characteristics of very large bandwidth (GHz or higher), very small substrate size along the optical path (typically 1.5 cm or less), single-mode optical propagation, and low drive power requirement. The devices utilize either acoustooptic, electrooptic or magnetooptic effects in planar or channel waveguides and, therefore, act as efficient interface devices between a light wave and temporal signals. Major areas of application lie in wideband multichannel optical real-time signal processing and communications. Some of the specific applications include spectral analysis and correlation of radio frequency (RF) signals, fiber-optic sensing, optical computing and multiport switching/routing, and analog-to-digital conversion of wide RF signals.

  14. Real time simulation using position sensing

    NASA Technical Reports Server (NTRS)

    Studor, George F. (Inventor); Womack, Robert W. (Inventor); Hilferty, Michael F. (Inventor); Isbell, William B. (Inventor); Taylor, Jason A. (Inventor); Bacon, Bruce R. (Inventor)

    2000-01-01

    An interactive exercise system including exercise equipment having a resistance system, a speed sensor, a controller that varies the resistance setting of the exercise equipment, and a playback device for playing pre-recorded video and audio. The controller, operating in conjunction with speed information from the speed sensor and terrain information from media table files, dynamically varies the resistance setting of the exercise equipment in order to simulate varying degrees of difficulty while the playback device concurrently plays back the video and audio to create the simulation that the user is exercising in a natural setting such as a real-world exercise course.

  15. A high-resolution, four-band SAR testbed with real-time image formation

    SciTech Connect

    Walker, B.; Sander, G.; Thompson, M.; Burns, B.; Fellerhoff, R.; Dubbert, D.

    1996-03-01

    This paper describes the Twin-Otter SAR Testbed developed at Sandia National Laboratories. This SAR is a flexible, adaptable testbed capable of operation on four frequency bands: Ka, Ku, X, and VHF/UHF bands. The SAR features real-time image formation at fine resolution in spotlight and stripmap modes. High-quality images are formed in real time using the overlapped subaperture (OSA) image-formation and phase gradient autofocus (PGA) algorithms.

  16. Time-Frequency Methods for Structural Health Monitoring †

    PubMed Central

    Pyayt, Alexander L.; Kozionov, Alexey P.; Mokhov, Ilya I.; Lang, Bernhard; Meijer, Robert J.; Krzhizhanovskaya, Valeria V.; Sloot, Peter M. A.

    2014-01-01

    Detection of early warning signals for the imminent failure of large and complex engineered structures is a daunting challenge with many open research questions. In this paper we report on novel ways to perform Structural Health Monitoring (SHM) of flood protection systems (levees, earthen dikes and concrete dams) using sensor data. We present a robust data-driven anomaly detection method that combines time-frequency feature extraction, using wavelet analysis and phase shift, with one-sided classification techniques to identify the onset of failure anomalies in real-time sensor measurements. The methodology has been successfully tested at three operational levees. We detected a dam leakage in the retaining dam (Germany) and “strange” behaviour of sensors installed in a Boston levee (UK) and a Rhine levee (Germany). PMID:24625740

  17. Time-frequency methods for structural health monitoring.

    PubMed

    Pyayt, Alexander L; Kozionov, Alexey P; Mokhov, Ilya I; Lang, Bernhard; Meijer, Robert J; Krzhizhanovskaya, Valeria V; Sloot, Peter M A

    2014-01-01

    Detection of early warning signals for the imminent failure of large and complex engineered structures is a daunting challenge with many open research questions. In this paper we report on novel ways to perform Structural Health Monitoring (SHM) of flood protection systems (levees, earthen dikes and concrete dams) using sensor data. We present a robust data-driven anomaly detection method that combines time-frequency feature extraction, using wavelet analysis and phase shift, with one-sided classification techniques to identify the onset of failure anomalies in real-time sensor measurements. The methodology has been successfully tested at three operational levees. We detected a dam leakage in the retaining dam (Germany) and "strange" behaviour of sensors installed in a Boston levee (UK) and a Rhine levee (Germany). PMID:24625740

  18. A perspective on time: Loss frequencies, time scales, and lifetimes

    NASA Astrophysics Data System (ADS)

    Prather, Michael; Holmes, Christopher

    2013-04-01

    The need to describe the Earth system and its components with a quantity that has units of time is ubiquitous since the 1970s work of Bolin, Rodhe and Junge. These quantities are often used as metrics of the system to describe the duration or cumulative impact of an action, such as in global-warming and ozone-depletion potentials, as in the SPARC lifetime re-assessment. The quantity designated "lifetime" is often calculated inconsistently and/or misused when applied to the subsequent evaluations of impacts. A careful set of definitions and derivations is needed to ensure that we are reporting, publishing, and comparing the same quantities. There are many different ways to derive metrics of time, and they describe different properties of the system. Here we carefully define several of those metrics - denoted here as loss frequency, time scale, and lifetime - and demonstrate which properties of the system they describe. Three generalizable examples demonstrate (i) how the non-linear chemistry of tropospheric ozone makes simple approaches for tracking pollution in error; (ii) why the lifetime of a gas depends on the history of emissions, and (iii) when multiple reservoirs generate time scales quite separate from the traditionally defined lifetime. Proper use of the many "time" parameters in a system, however, gives a very powerful understanding of the response to anthropogenic perturbations.

  19. Time-frequency methods for signal analysis in wind turbines

    NASA Astrophysics Data System (ADS)

    Kalista, Karel; Liska, Jindrich

    2015-11-01

    Since wind turbines became one of the most often source of renewable energy, appropriate health and condition monitoring systems are required. Especially proper monitoring of offshore plants is very significant because the accessibility is difficult and inspections are very costly. In comparison with conventional rotating machine vibration monitoring, where steady conditions and stationary signal are usually assumed, the wind turbines are characterized by unsteady conditions due to variable rotational speed. Hence the vibration signal is non-stationary and interpretation of signal signatures may be more complex. The common approach to analyze such non-stationary signals is the use of a time-frequency method, usually Short-Time Fourier Transform, which is the most popular one due to its simplicity. Nevertheless, there are other methods which can give a different view at the analyzed data and provide new information. This article investigates the potential use of some other time-frequency methods, namely Wavelet Transform, Wigner-Ville distribution and Hilbert-Huang transform in wind plants monitoring systems and apply these methods to real measured data with additional simulated bearing fault signal. Finally, the mentioned methods are compared based on computational complexity, readability and interpretability. Though the last two criteria are very subjective, Short-Time Fourier Transform was finally chosen as the most effective method followed by Wavelet Transform.

  20. Real-time Avatar Animation from a Single Image

    PubMed Central

    Saragih, Jason M.; Lucey, Simon; Cohn, Jeffrey F.

    2014-01-01

    A real time facial puppetry system is presented. Compared with existing systems, the proposed method requires no special hardware, runs in real time (23 frames-per-second), and requires only a single image of the avatar and user. The user’s facial expression is captured through a real-time 3D non-rigid tracking system. Expression transfer is achieved by combining a generic expression model with synthetically generated examples that better capture person specific characteristics. Performance of the system is evaluated on avatars of real people as well as masks and cartoon characters. PMID:24598812

  1. A real-time photogrammetry system based on embedded architecture

    NASA Astrophysics Data System (ADS)

    Zheng, S. Y.; Gui, L.; Wang, X. N.; Ma, D.

    2014-06-01

    In order to meet the demand of real-time spatial data processing and improve the online processing capability of photogrammetric system, a kind of real-time photogrammetry method is proposed in this paper. According to the proposed method, system based on embedded architecture is then designed: using FPGA, ARM+DSP and other embedded computing technology to build specialized hardware operating environment, transplanting and optimizing the existing photogrammetric algorithm to the embedded system, and finally real-time photogrammetric data processing is realized. At last, aerial photogrammetric experiment shows that the method can achieve high-speed and stable on-line processing of photogrammetric data. And the experiment also verifies the feasibility of the proposed real-time photogrammetric system based on embedded architecture. It is the first time to realize real-time aerial photogrammetric system, which can improve the online processing efficiency of photogrammetry to a higher level and broaden the application field of photogrammetry.

  2. Gaussian Molecular Dynamics in Imaginary and Real Time

    NASA Astrophysics Data System (ADS)

    Georgescu, Ionut; Mandelshtam, Vladimir

    2010-03-01

    The variational Gaussian wavepacket (VGW) method can be used to estimate the equilibrium density matrix by propagating Gaussian wavepackets in imaginary time [1,2]. It has proven to be practically accurate and computationally less expensive than the path integral methods. We compare the VGW method to the Feynman-Kleinert approximation (FKA), which has comparable computational cost. Although both methods are variational, they utilize different variational principles: In FKA the partition function is optimized, while in VGW it is the imaginary-time-dependent wave packet. We show that the VGW method is more accurate for a wide variety of systems. The differences are particularly important when thermodynamic properties, such as heat capacity, are of main interest. Moreover, unlike the case of FKA, in the VGW method the imaginary frequencies do not arise. In the spirit of the Centroid Molecular Dynamics the VGW method has also been extended to simulate the real-time dynamics, e.g., it can be used to estimate the Kubo-transformed quantum time correlation functions. The latter are exact in the high-temperature and harmonic limits. [1] P. Frantsuzov and V.A. Mandelshtam, J. Chem. Phys 121, 9247 (2004)[2] C. Predescu, P. Frantsuzov and V.A. Mandelshtam J. Chem. Phys 122, 154305 (2005)

  3. Estimating correlation for a real-time measure of connectivity.

    PubMed

    Arunkumar, Akhil; Panday, Ashish; Joshi, Bharat; Ravindran, Arun; Zaveri, Hitten P

    2012-01-01

    There has recently been considerable interest in connectivity analysis of fMRI and scalp and intracranial EEG time-series. The computational requirements of the pair-wise correlation (PWC), the core time-series measure used to estimate connectivity, presents a challenge to the real-time estimation of the PWC between all pairs of multiple time-series. We describe a parallel algorithm for computing PWC in real-time for streaming data from multiple channels. The algorithm was implemented on the Intel Xeon™ and IBM Cell Broadband Engine™ platforms. We evaluated time to estimate correlation for signals recorded with different acquisition parameters as a comparison to real-time constraints. We demonstrate that the execution time of these efficient implementations meet real-time constraints in most instances. PMID:23367098

  4. REAL-TIME ENVIRONMENTAL MONITORING: APPLICATIONS FOR HOMELAND SECURITY

    EPA Science Inventory

    Real-time monitoring technology developed as part of the EMPACT program has a variety of potential applications. These tools can measure a variety of potential contaminants in the air, water, in buildings, or in the soil. Real-time monitoring technology allows these detection sys...

  5. 75 FR 68418 - Real-Time System Management Information Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-08

    ... successful real-time information program. A Request for Comments was published on May 4, 2006, at 71 FR 26399... 14, 2009, at 74 FR 1993. The purpose was to propose the establishment of minimum parameters and... Federal Highway Administration 23 CFR Part 511 RIN 2125-AF19 Real-Time System Management...

  6. 76 FR 42536 - Real-Time System Management Information Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-19

    ... System Management Information Program on November 8, 2010, at 75 FR 68418. The final rule document also... Federal Highway Administration 23 CFR Part 511 RIN 2125-AF19 Real-Time System Management Information... available and share traffic and travel conditions information via real-time information programs as...

  7. REAL-TIME PCR ASSAY DEVELOPMENT FOR MULTIPLE MAIZE PATHOGENS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This talk presents updates on the development of real-time PCR assays for two seedborne pathogens of maize, Pantoea (Erwinia) stewartii, the causal agent of Stewart's bacterial wilt, and Stenocarpella (Diplodia) maydis, the causal agent of Diplodia ear rot. We developed primers and a real-time PCR p...

  8. COMPUTER-CONTROLLED, REAL-TIME AUTOMOBILE EMISSIONS MONITORING SYSTEM

    EPA Science Inventory

    A minicomputer controlled automotive emissions sampling and analysis system (the Real-Time System) was developed to determine vehicular modal emissions over various test cycles. This data acquisition system can sample real-time emissions at a rate of 10 samples/s. A buffer utiliz...

  9. Real-time hyperspectral imaging for food safety applications

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Multispectral imaging systems with selected bands can commonly be used for real-time applications of food processing. Recent research has demonstrated several image processing methods including binning, noise removal filter, and appropriate morphological analysis in real-time mode can remove most fa...

  10. "Real-Time" Case Studies in Organizational Communication

    ERIC Educational Resources Information Center

    Long, Shawn D.

    2005-01-01

    This article presents an activity that integrates theory and application by examining the multiple communication events affecting a single organization in "real time" over the course of an academic term. The "real-time" case study (RTCS) avails students of the opportunity to examine organizational communication events as they are occurring in…

  11. Real-time fault diagnosis for propulsion systems

    NASA Technical Reports Server (NTRS)

    Merrill, Walter C.; Guo, Ten-Huei; Delaat, John C.; Duyar, Ahmet

    1991-01-01

    Current research toward real time fault diagnosis for propulsion systems at NASA-Lewis is described. The research is being applied to both air breathing and rocket propulsion systems. Topics include fault detection methods including neural networks, system modeling, and real time implementations.

  12. A reconfigurable real-time morphological system for augmented vision

    NASA Astrophysics Data System (ADS)

    Gibson, Ryan M.; Ahmadinia, Ali; McMeekin, Scott G.; Strang, Niall C.; Morison, Gordon

    2013-12-01

    There is a significant number of visually impaired individuals who suffer sensitivity loss to high spatial frequencies, for whom current optical devices are limited in degree of visual aid and practical application. Digital image and video processing offers a variety of effective visual enhancement methods that can be utilised to obtain a practical augmented vision head-mounted display device. The high spatial frequencies of an image can be extracted by edge detection techniques and overlaid on top of the original image to improve visual perception among the visually impaired. Augmented visual aid devices require highly user-customisable algorithm designs for subjective configuration per task, where current digital image processing visual aids offer very little user-configurable options. This paper presents a highly user-reconfigurable morphological edge enhancement system on field-programmable gate array, where the morphological, internal and external edge gradients can be selected from the presented architecture with specified edge thickness and magnitude. In addition, the morphology architecture supports reconfigurable shape structuring elements and configurable morphological operations. The proposed morphology-based visual enhancement system introduces a high degree of user flexibility in addition to meeting real-time constraints capable of obtaining 93 fps for high-definition image resolution.

  13. Information display and interaction in real-time environments

    NASA Technical Reports Server (NTRS)

    Bocast, A. K.

    1983-01-01

    The available information bandwidth as a funcion of system's complexity and time constraints in a real time control environment were examined. Modern interactive graphics techniques provide very high bandwidth data displays. In real time control environments, effective information interaction rates are a function not only of machine data technologies but of human information processing capabilities and the four dimensional resolution of available interaction techniques. The available information bandwidth as a function of system's complexity and time constraints in a real time control environment were examined.

  14. Hardware for a real-time multiprocessor simulator

    NASA Technical Reports Server (NTRS)

    Blech, R. A.; Arpasi, D. J.

    1984-01-01

    The hardware for a real time multiprocessor simulator (RTMPS) developed at the NASA Lewis Research Center is described. The RTMPS is a multiple microprocessor system used to investigate the application of parallel processing concepts to real time simulation. It is designed to provide flexible data exchange paths between processors by using off the shelf microcomputer boards and minimal customized interfacing. A dedicated operator interface allows easy setup of the simulator and quick interpreting of simulation data. Simulations for the RTMPS are coded in a NASA designed real time multiprocessor language (RTMPL). This language is high level and geared to the multiprocessor environment. A real time multiprocessor operating system (RTMPOS) has also been developed that provides a user friendly operator interface. The RTMPS and supporting software are currently operational and are being evaluated at Lewis. The results of this evaluation will be used to specify the design of an optimized parallel processing system for real time simulation of dynamic systems.

  15. A real-time simulator of a turbofan engine

    NASA Technical Reports Server (NTRS)

    Litt, Jonathan S.; Delaat, John C.; Merrill, Walter C.

    1989-01-01

    A real-time digital simulator of a Pratt and Whitney F100 engine has been developed for real-time code verification and for actuator diagnosis during full-scale engine testing. This self-contained unit can operate in an open-loop stand-alone mode or as part of closed-loop control system. It can also be used for control system design and development. Tests conducted in conjunction with the NASA Advanced Detection, Isolation, and Accommodation program show that the simulator is a valuable tool for real-time code verification and as a real-time actuator simulator for actuator fault diagnosis. Although currently a small perturbation model, advances in microprocessor hardware should allow the simulator to evolve into a real-time, full-envelope, full engine simulation.

  16. Recent advances to obtain real - Time displacements for engineering applications

    USGS Publications Warehouse

    Celebi, M.

    2005-01-01

    This paper presents recent developments and approaches (using GPS technology and real-time double-integration) to obtain displacements and, in turn, drift ratios, in real-time or near real-time to meet the needs of the engineering and user community in seismic monitoring and assessing the functionality and damage condition of structures. Drift ratios computed in near real-time allow technical assessment of the damage condition of a building. Relevant parameters, such as the type of connections and story structural characteristics (including geometry) are used in computing drifts corresponding to several pre-selected threshold stages of damage. Thus, drift ratios determined from real-time monitoring can be compared to pre-computed threshold drift ratios. The approaches described herein can be used for performance evaluation of structures and can be considered as building health-monitoring applications.

  17. Real-Time Simulator of Black Hole Optics

    NASA Astrophysics Data System (ADS)

    Bakala, Pavel; Sramkova, Eva; Torok, Gabriel; Goluchova, Katerina

    Our electronic poster presents complex hardware and software simulator of an optical projection for an observer in strong gravitational field of axially symmetric rotating black holes described by the Kerr metric, spherically symmetric Schwarzschild black holes and compact neutron or quark stars. The real-time simulation was created by the application of advanced numerical methods for the integration of zero geodesics and massive parallel computing. The simulation software scans the surroundings and transforms them into a form of an optical projection in the local reference frame of the observers who are inside and outside the ergosphere, above and below the circular photon orbit and in the close vicinity of the black hole’s horizon or at the surface of a neutron star. The simulation contains all the characteristic effects of relativistic optics: multiple direct and indirect pictures, the gravitational and Doppler frequency shift, and the amplification of the intensity of the observed emission. The hardware part of the simulator uses two large TV monitors, four cameras for scanning the surroundings and two powerful laptops. This hardware configuration allows to process the whole surroundings around full 360 degrees and to model their relativistic optical projection in real time. The interactive computer simulation explicitly demonstrates the significant difference between the optics in the strong gravitational field background and the optics we know from our daily life. The properties of the latter, being seemingly obvious, have determined our perception, intuition and imagination from time immemorial. The simulator therefore provides the chance of an intuitive insight into the properties of the curved spacetimes in the vicinity of compact objects to the general public without specific knowledge of mathematical and physical background.

  18. Sparse time-frequency decomposition based on dictionary adaptation.

    PubMed

    Hou, Thomas Y; Shi, Zuoqiang

    2016-04-13

    In this paper, we propose a time-frequency analysis method to obtain instantaneous frequencies and the corresponding decomposition by solving an optimization problem. In this optimization problem, the basis that is used to decompose the signal is not known a priori. Instead, it is adapted to the signal and is determined as part of the optimization problem. In this sense, this optimization problem can be seen as a dictionary adaptation problem, in which the dictionary is adaptive to one signal rather than a training set in dictionary learning. This dictionary adaptation problem is solved by using the augmented Lagrangian multiplier (ALM) method iteratively. We further accelerate the ALM method in each iteration by using the fast wavelet transform. We apply our method to decompose several signals, including signals with poor scale separation, signals with outliers and polluted by noise and a real signal. The results show that this method can give accurate recovery of both the instantaneous frequencies and the intrinsic mode functions. PMID:26953172

  19. Reviewing real-time performance of nuclear reactor safety systems

    SciTech Connect

    Preckshot, G.G.

    1993-08-01

    The purpose of this paper is to recommend regulatory guidance for reviewers examining real-time performance of computer-based safety systems used in nuclear power plants. Three areas of guidance are covered in this report. The first area covers how to determine if, when, and what prototypes should be required of developers to make a convincing demonstration that specific problems have been solved or that performance goals have been met. The second area has recommendations for timing analyses that will prove that the real-time system will meet its safety-imposed deadlines. The third area has description of means for assessing expected or actual real-time performance before, during, and after development is completed. To ensure that the delivered real-time software product meets performance goals, the paper recommends certain types of code-execution and communications scheduling. Technical background is provided in the appendix on methods of timing analysis, scheduling real-time computations, prototyping, real-time software development approaches, modeling and measurement, and real-time operating systems.

  20. Real-Time MEG Source Localization Using Regional Clustering.

    PubMed

    Dinh, Christoph; Strohmeier, Daniel; Luessi, Martin; Güllmar, Daniel; Baumgarten, Daniel; Haueisen, Jens; Hämäläinen, Matti S

    2015-11-01

    With its millisecond temporal resolution, Magnetoencephalography (MEG) is well suited for real-time monitoring of brain activity. Real-time feedback allows the adaption of the experiment to the subject's reaction and increases time efficiency by shortening acquisition and off-line analysis. Two formidable challenges exist in real-time analysis: the low signal-to-noise ratio (SNR) and the limited time available for computations. Since the low SNR reduces the number of distinguishable sources, we propose an approach which downsizes the source space based on a cortical atlas and allows to discern the sources in the presence of noise. Each cortical region is represented by a small set of dipoles, which is obtained by a clustering algorithm. Using this approach, we adapted dynamic statistical parametric mapping for real-time source localization. In terms of point spread and crosstalk between regions the proposed clustering technique performs better than selecting spatially evenly distributed dipoles. We conducted real-time source localization on MEG data from an auditory experiment. The results demonstrate that the proposed real-time method localizes sources reliably in the superior temporal gyrus. We conclude that real-time source estimation based on MEG is a feasible, useful addition to the standard on-line processing methods, and enables feedback based on neural activity during the measurements. PMID:25782980

  1. Overview of real-time computer systems technical analysis of the Modcomp implementation of a proprietary system MAX IV'' and real-time UNIX system REAL/IX''

    SciTech Connect

    Cummings, J.

    1990-10-01

    There many applications throughout industry and government requiring real-time computing. Any application that monitors and/or controls a process would fit into this category. Some examples are: Nuclear power plants, Steel mills, Space program, etc. General Atomics uses eight real-time computer systems for control and high speed data acquisition required to run the nuclear fusion experiments. Real-Time computing can be defined as the ability to respond to asynchronous external events in a predictable (preferably fast) time frame. Real-Time computer systems are similar to other computers in many ways and may by used for general computing requirements such as Time-Sharing. However special hardware, operating systems and software had to be developed to meet the requirement for real-time computing. Traditionally, real-time computing has been a realm of proprietary operating systems with real-time applications written in FORTRAN and assembly language. In the past, these systems adequately served the needs of the real-time world. Many of these systems that were developed 15 years ago are still being used today. However the real-time world is now changing, demanding new systems to be developed. This paper gives a description of general real-time computer systems and how they differ from other systems. However, the main purpose of this paper is to give a detailed technical description of the hardware and operating systems of an existing proprietary system and a real-time UNIX system. The two real-time computer systems described in detail are Modcomp Classic III/95 with the MAX IV operating system and Modcomp TRI-D 9750 with the REAL/IX.2 operating system.

  2. Expert systems for real-time monitoring and fault diagnosis

    NASA Technical Reports Server (NTRS)

    Edwards, S. J.; Caglayan, A. K.

    1989-01-01

    Methods for building real-time onboard expert systems were investigated, and the use of expert systems technology was demonstrated in improving the performance of current real-time onboard monitoring and fault diagnosis applications. The potential applications of the proposed research include an expert system environment allowing the integration of expert systems into conventional time-critical application solutions, a grammar for describing the discrete event behavior of monitoring and fault diagnosis systems, and their applications to new real-time hardware fault diagnosis and monitoring systems for aircraft.

  3. Real-Time Geospatial Data Viewer (RETIGO)

    EPA Science Inventory

    This is a web-based method that allows the users to upload their air monitoring data and explore the data on graphical interface. The method is optimized for mobile monitoring data sets, showing the data on a map, on a time series, and referenced to a hypothesized line and/or poi...

  4. Real-time atmospheric chemistry field instrumentation.

    PubMed

    Farmer, Delphine K; Jimenez, Jose L

    2010-10-01

    Quantifying the concentrations of trace atmospheric species in complex, reactive, and constantly changing gas and particle mixtures is challenging. This article provides a broad overview of recent advances in instrumentation used for analyzing ambient gases and particles continuously and with fast time resolution during field campaigns. PMID:20722374

  5. Real time chemical dynamics at surfaces

    NASA Astrophysics Data System (ADS)

    Bonn, M.; Kleyn, A. W.; Kroes, G. J.

    2002-03-01

    It is a major goal in surface science to make movies of molecules on surfaces, in which the reaction of the molecules on the surface can be followed on a femtosecond time scale, with sub-nanometer resolution. By moving the actors (the molecules) to precisely determined positions on the stage (the surface) at some well-defined moment in time, and subsequently making a space- and time-resolved documentary of what happens next, we would be able to understand the reactive interactions between molecules on surfaces in the greatest possible detail. This would enable us to set the stage and bring together the actors in such a way as to produce the chemical outcomes our society needs, by improving existing catalysts and designing novel catalysts, and by engineering novel reactions on surfaces. Any future director of such movies needs to know which techniques (i.e., which theoretical and experimental methods) hold promise for movie making, what has been done with these techniques, and what can be done with appropriate extensions. The methods we discuss are: (i) the time-dependent wave packet method, which is a theoretical method for simulating molecule-surface reactions with sub-nanometer resolution on a femtosecond time scale, (ii) molecular beam experiments, which allow detailed investigation of the molecule-surface interaction at a molecular level, and (iii) time-resolved laser pump-probe experiments, which allow reactions to be studied with femtosecond resolution. In particular, we discuss (i) theoretical studies of the dissociation reaction of hydrogen on metal surfaces, the reactive system presently understood at the greatest level of detail, (ii) the reactive and non-reactive scattering of heavy diatomics (NO,CO) from metal surfaces, and (iii) the competition between reaction of coadsorbed CO with O and desorption of CO, again on a metal surface. We examine possibilities to extend these methods to make movies at the desired level of detail. We also discuss which

  6. Expert Systems for Real-Time Volcano Monitoring

    NASA Astrophysics Data System (ADS)

    Cassisi, C.; Cannavo, F.; Montalto, P.; Motta, P.; Schembra, G.; Aliotta, M. A.; Cannata, A.; Patanè, D.; Prestifilippo, M.

    2014-12-01

    In the last decade, the capability to monitor and quickly respond to remote detection of volcanic activity has been greatly improved through use of advanced techniques and semi-automatic software applications installed in most of the 24h control rooms devoted to volcanic surveillance. Ability to monitor volcanoes is being advanced by new technology, such as broad-band seismology, microphone networks mainly recording in the infrasonic frequency band, satellite observations of ground deformation, high quality video surveillance systems, also in infrared band, improved sensors for volcanic gas measurements, and advances in computer power and speed, leading to improvements in data transmission, data analysis and modeling techniques. One of the most critical point in the real-time monitoring chain is the evaluation of the volcano state from all the measurements. At the present, most of this task is delegated to one or more human experts in volcanology. Unfortunately, the volcano state assessment becomes harder if we observe that, due to the coupling of highly non-linear and complex volcanic dynamic processes, the measurable effects can show a rich range of different behaviors. Moreover, due to intrinsic uncertainties and possible failures in some recorded data, precise state assessment is usually not achievable. Hence, the volcano state needs to be expressed in probabilistic terms that take account of uncertainties. In the framework of the project PON SIGMA (Integrated Cloud-Sensor System for Advanced Multirisk Management) work, we have developed an expert system approach to estimate the ongoing volcano state from all the available measurements and with minimal human interaction. The approach is based on hidden markov model and deals with uncertainties and probabilities. We tested the proposed approach on data coming from the Mt. Etna (Italy) continuous monitoring networks for the period 2011-2013. Results show that this approach can be a valuable tool to aid the

  7. Real-time adaptive aircraft scheduling

    NASA Technical Reports Server (NTRS)

    Kolitz, Stephan E.; Terrab, Mostafa

    1990-01-01

    One of the most important functions of any air traffic management system is the assignment of ground-holding times to flights, i.e., the determination of whether and by how much the take-off of a particular aircraft headed for a congested part of the air traffic control (ATC) system should be postponed in order to reduce the likelihood and extent of airborne delays. An analysis is presented for the fundamental case in which flights from many destinations must be scheduled for arrival at a single congested airport; the formulation is also useful in scheduling the landing of airborne flights within the extended terminal area. A set of approaches is described for addressing a deterministic and a probabilistic version of this problem. For the deterministic case, where airport capacities are known and fixed, several models were developed with associated low-order polynomial-time algorithms. For general delay cost functions, these algorithms find an optimal solution. Under a particular natural assumption regarding the delay cost function, an extremely fast (O(n ln n)) algorithm was developed. For the probabilistic case, using an estimated probability distribution of airport capacities, a model was developed with an associated low-order polynomial-time heuristic algorithm with useful properties.

  8. Toward Real Time Uavs' Image Mosaicking

    NASA Astrophysics Data System (ADS)

    Mehrdad, S.; Satari, M.; Safdary, M.; Moallem, P.

    2016-06-01

    Anyone knows that sudden catastrophes can instantly do great damage. Fast and accurate acquisition of catastrophe information is an essential task for minimize life and property damage. Compared with other ways of catastrophe data acquisition, UAV based platforms can optimize time, cost and accuracy of the data acquisition, as a result UAVs' data has become the first choice in such condition. In this paper, a novel and fast strategy is proposed for registering and mosaicking of UAVs' image data. Firstly, imprecise image positions are used to find adjoining frames. Then matching process is done by a novel matching method. With keeping Sift in mind, this fast matching method is introduced, which uses images exposure time geometry, SIFT point detector and rBRIEF descriptor vector in order to match points efficiency, and by efficiency we mean not only time efficiency but also elimination of mismatch points. This method uses each image sequence imprecise attitude in order to use Epipolar geometry to both restricting search space of matching and eliminating mismatch points. In consideration of reaching to images imprecise attitude and positions we calibrated the UAV's sensors. After matching process, RANSAC is used to eliminate mismatched tie points. In order to obtain final mosaic, image histograms are equalized and a weighted average method is used to image composition in overlapping areas. The total RMSE over all matching points is 1.72 m.

  9. Some aspects of improving Multi-GNSS real-time precise point positioning services

    NASA Astrophysics Data System (ADS)

    Liu, Yang; Ge, Maorong; Li, Xingxing; Schuh, Harald

    2016-04-01

    Multi-GNSS is expected to achieve a real-time precise point positioning service with better accuracy and reliability than GPS-only service. In this contribution, we address several critical challenges in implementing a GPS+GLONASS+BeiDou+Galileo service to provide global users with centimeter-level positioning in real-time based on the software system developed at GFZ. The specific issues of improving GLONASS orbit quality by resolving ambiguity over long baselines, estimation of inter-system/frequency biases, ambiguity resolution in real-time clock estimation and positioning, and computation efficiency are discussed and investigated in detail. Experimental validation is carried out based on the data streams of the IGS/MGEX network. The real-time orbit and clock products are assessed by comparison with the IGS/MGEX final products, and orbits are also assessed by overlapping day boundaries and satellite laser ranging. The phase bias (uncalibrated phase delay) products are evaluated by comparison with the post-processing results. It is demonstrated that multi-GNSS can contribute significantly to improving the global real-time precise point positioning service in terms of convergence time and accuracy. Keywords: Multi-GNSS, Real-Time, Precise Orbit Determination, Precise Point Positioning, Ambiguity Resolution, Inter-System/Frequency Bias, Algorithm Efficiency

  10. 17 CFR 43.3 - Method and timing for real-time public reporting.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... COMMISSION (CONTINUED) REAL-TIME PUBLIC REPORTING § 43.3 Method and timing for real-time public reporting. (a) Responsibilities of parties to a swap to report swap transaction and pricing data in real-time—(1) In general. A... repositories in providing the public dissemination of swap transaction and pricing data in...

  11. 17 CFR 43.3 - Method and timing for real-time public reporting.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... COMMISSION REAL-TIME PUBLIC REPORTING § 43.3 Method and timing for real-time public reporting. (a) Responsibilities of parties to a swap to report swap transaction and pricing data in real-time—(1) In general. A... repositories in providing the public dissemination of swap transaction and pricing data in...

  12. 17 CFR 43.3 - Method and timing for real-time public reporting.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... COMMISSION REAL-TIME PUBLIC REPORTING § 43.3 Method and timing for real-time public reporting. (a) Responsibilities of parties to a swap to report swap transaction and pricing data in real-time—(1) In general. A... repositories in providing the public dissemination of swap transaction and pricing data in...

  13. Space Shuttle Main Engine real time stability analysis

    NASA Astrophysics Data System (ADS)

    Kuo, F. Y.

    1993-06-01

    The Space Shuttle Main Engine (SSME) is a reusable, high performance, liquid rocket engine with variable thrust. The engine control system continuously monitors the engine parameters and issues propellant valve control signals in accordance with the thrust and mixture ratio commands. A real time engine simulation lab was installed at MSFC to verify flight software and to perform engine dynamic analysis. A real time engine model was developed on the AD100 computer system. This model provides sufficient fidelity on the dynamics of major engine components and yet simplified enough to be executed in real time. The hardware-in-the-loop type simulation and analysis becomes necessary as NASA is continuously improving the SSME technology, some with significant changes in the dynamics of the engine. The many issues of interfaces between new components and the engine can be better understood and be resolved prior to the firing of the engine. In this paper, the SSME real time simulation Lab at the MSFC, the SSME real time model, SSME engine and control system stability analysis, both in real time and non-real time is presented.

  14. High-density FPGAs for real-time video processing

    NASA Astrophysics Data System (ADS)

    Nordhauser, Steven; Beckstead, Jeffrey A.; Castracane, James; Koltai, Peter J.; Mouzakes, Jason; Simkulet, Michelle D.

    1997-04-01

    The use of an off-the-shelf general purpose processing system supplied by Giga Operations as applied to real-time video applications is described. The system is modular enough to be used in many scientific and industrial applications and powerful enough to maintain the throughput required for real-time video processing. This hardware and the associated programming environment has enabled InterScience to pursue research in real-time data compression, real-time Electronic Speckle Pattern Interferometry (ESPI) image processing, and industrial quality control and manufacturing. The system is based on Xilinx 4000 series field programmable gate arrays with associated static and dynamic random access memory in an architecture optimized for video processing on either the VL-Bus or PCI. This paper will focus on the design and development of a real-time frame subtractor for ESPI using this technology. Examples of the improvement in research capability provided by real-time frame subtraction are shown, including images from biomedical experiments. Further applications, based on this system are described. These include real-time data compression, quality control for production lines as part of an automated inspection system and a multi-camera security system allowing motion estimation to automatically prioritize camera selection.

  15. Vector processing enhancements for real-time image analysis.

    SciTech Connect

    Shoaf, S.; APS Engineering Support Division

    2008-01-01

    A real-time image analysis system was developed for beam imaging diagnostics. An Apple Power Mac G5 with an Active Silicon LFG frame grabber was used to capture video images that were processed and analyzed. Software routines were created to utilize vector-processing hardware to reduce the time to process images as compared to conventional methods. These improvements allow for more advanced image processing diagnostics to be performed in real time.

  16. Real Time Telemetry Data Capture and Storage

    Energy Science and Technology Software Center (ESTSC)

    1997-05-14

    This program is used to capture telemetry data from remote instrumentation systems. The data can be captured at the rate of 1M bit per second. The data can come in one of several formats, NRZ, RZ, and Bi-Phase. The DECOM software takes the serial data stream and locks on to a unique code word. By tracking the code word the software can strip out the information. Thus the program can display the incoming data realmore » time while saving the data to disk.« less

  17. Real-Time Dynamic Modeling - Data Information Requirements and Flight Test Results

    NASA Technical Reports Server (NTRS)

    Morelli, Eugene A.; Smith, Mark S.

    2010-01-01

    Practical aspects of identifying dynamic models for aircraft in real time were studied. Topics include formulation of an equation-error method in the frequency domain to estimate non-dimensional stability and control derivatives in real time, data information content for accurate modeling results, and data information management techniques such as data forgetting, incorporating prior information, and optimized excitation. Real-time dynamic modeling was applied to simulation data and flight test data from a modified F-15B fighter aircraft, and to operational flight data from a subscale jet transport aircraft. Estimated parameter standard errors, prediction cases, and comparisons with results from a batch output-error method in the time domain were used to demonstrate the accuracy of the identified real-time models.

  18. Real-Time Dynamic Modeling - Data Information Requirements and Flight Test Results

    NASA Technical Reports Server (NTRS)

    Morelli, Eugene A.; Smith, Mark S.

    2008-01-01

    Practical aspects of identifying dynamic models for aircraft in real time were studied. Topics include formulation of an equation-error method in the frequency domain to estimate non-dimensional stability and control derivatives in real time, data information content for accurate modeling results, and data information management techniques such as data forgetting, incorporating prior information, and optimized excitation. Real-time dynamic modeling was applied to simulation data and flight test data from a modified F-15B fighter aircraft, and to operational flight data from a subscale jet transport aircraft. Estimated parameter standard errors and comparisons with results from a batch output-error method in the time domain were used to demonstrate the accuracy of the identified real-time models.

  19. Black Hole Formation in Real Time

    NASA Astrophysics Data System (ADS)

    Nissanke, Samaya

    2015-08-01

    Gravity plays a fundamental role in the formation, evolution and fate of stars. However, it remains unclear how massive stars, almost always in pairs, end their lives as extreme gravity objects (neutron stars and black holes) and what their eventual fate is. The physics driving these events in strong-field gravity are complex, rich but still remain elusive. Theoretical work in general relativity has long predicted that the formation of black holes through neutron star mergers emit vast amounts of gravitational radiation, through gravitational waves (GWs), and conventional electromagnetic (EM) radiation. Observing GWs and EM radiation from these elusive short-lived mergers remains one of the holy grails of modern astronomy and is only now possible with a suite of new time-domain telescopes and experiments. I will first review the most recent advances in this blossoming field of EM+GW astronomy, which combines three active disciplines: time-domain astronomy, computational astrophysics and general relativity. I will discuss the promises of this new convergence by illustrating the wealth of astrophysical information that a combined EM+GW measurement would immediately bring. I will then outline the main challenges that lie ahead for this new field in pinpointing the sky location of neutron star mergers using GW detectors and optical and radio wide-field synoptic surveys.

  20. Real-time dynamic simulation of the Cassini spacecraft using DARTS. Part 2: Parallel/vectorized real-time implementation

    NASA Technical Reports Server (NTRS)

    Fijany, A.; Roberts, J. A.; Jain, A.; Man, G. K.

    1993-01-01

    Part 1 of this paper presented the requirements for the real-time simulation of Cassini spacecraft along with some discussion of the DARTS algorithm. Here, in Part 2 we discuss the development and implementation of parallel/vectorized DARTS algorithm and architecture for real-time simulation. Development of the fast algorithms and architecture for real-time hardware-in-the-loop simulation of spacecraft dynamics is motivated by the fact that it represents a hard real-time problem, in the sense that the correctness of the simulation depends on both the numerical accuracy and the exact timing of the computation. For a given model fidelity, the computation should be computed within a predefined time period. Further reduction in computation time allows increasing the fidelity of the model (i.e., inclusion of more flexible modes) and the integration routine.

  1. Method for Real-Time Model Based Structural Anomaly Detection

    NASA Technical Reports Server (NTRS)

    Smith, Timothy A. (Inventor); Urnes, James M., Sr. (Inventor); Reichenbach, Eric Y. (Inventor)

    2015-01-01

    A system and methods for real-time model based vehicle structural anomaly detection are disclosed. A real-time measurement corresponding to a location on a vehicle structure during an operation of the vehicle is received, and the real-time measurement is compared to expected operation data for the location to provide a modeling error signal. A statistical significance of the modeling error signal to provide an error significance is calculated, and a persistence of the error significance is determined. A structural anomaly is indicated, if the persistence exceeds a persistence threshold value.

  2. Real Time Target Tracking in a Phantom Using Ultrasonic Imaging

    NASA Astrophysics Data System (ADS)

    Xiao, X.; Corner, G.; Huang, Z.

    In this paper we present a real-time ultrasound image guidance method suitable for tracking the motion of tumors. A 2D ultrasound based motion tracking system was evaluated. A robot was used to control the focused ultrasound and position it at the target that has been segmented from a real-time ultrasound video. Tracking accuracy and precision were investigated using a lesion mimicking phantom. Experiments have been conducted and results show sufficient efficiency of the image guidance algorithm. This work could be developed as the foundation for combining the real time ultrasound imaging tracking and MRI thermometry monitoring non-invasive surgery.

  3. Can Real-Time Data Also Be Climate Quality?

    NASA Astrophysics Data System (ADS)

    Brewer, M.; Wentz, F. J.

    2015-12-01

    GMI, AMSR-2 and WindSat herald a new era of highly accurate and timely microwave data products. Traditionally, there has been a large divide between real-time and re-analysis data products. What if these completely separate processing systems could be merged? Through advanced modeling and physically based algorithms, Remote Sensing Systems (RSS) has narrowed the gap between real-time and research-quality. Satellite microwave ocean products have proven useful for a wide array of timely Earth science applications. Through cloud SST capabilities have enormously benefited tropical cyclone forecasting and day to day fisheries management, to name a few. Oceanic wind vectors enhance operational safety of shipping and recreational boating. Atmospheric rivers are of import to many human endeavors, as are cloud cover and knowledge of precipitation events. Some activities benefit from both climate and real-time operational data used in conjunction. RSS has been consistently improving microwave Earth Science Data Records (ESDRs) for several decades, while making near real-time data publicly available for semi-operational use. These data streams have often been produced in 2 stages: near real-time, followed by research quality final files. Over the years, we have seen this time delay shrink from months or weeks to mere hours. As well, we have seen the quality of near real-time data improve to the point where the distinction starts to blur. We continue to work towards better and faster RFI filtering, adaptive algorithms and improved real-time validation statistics for earlier detection of problems. Can it be possible to produce climate quality data in real-time, and what would the advantages be? We will try to answer these questions…

  4. Real-time cosmography with redshift derivatives

    NASA Astrophysics Data System (ADS)

    Martins, C. J. A. P.; Martinelli, M.; Calabrese, E.; Ramos, M. P. L. P.

    2016-08-01

    The drift in the redshift of objects passively following the cosmological expansion has long been recognized as a key model-independent probe of cosmology. Here, we study the cosmological relevance of measurements of time or redshift derivatives of this drift, arguing that the combination of first and second redshift derivatives is a powerful test of the Λ CDM cosmological model. In particular, the latter can be obtained numerically from a set of measurements of the drift at different redshifts. We show that, in the low-redshift limit, a measurement of the derivative of the drift can provide a constraint on the jerk parameter, which is j =1 for flat Λ CDM , while generically j ≠1 for other models. We emphasize that such a measurement is well within the reach of the ELT-HIRES and SKA Phase 2 array surveys.

  5. Real-time airborne particle analyzer

    DOEpatents

    Reilly, Peter T.A.

    2012-10-16

    An aerosol particle analyzer includes a laser ablation chamber, a gas-filled conduit, and a mass spectrometer. The laser ablation chamber can be operated at a low pressure, which can be from 0.1 mTorr to 30 mTorr. The ablated ions are transferred into a gas-filled conduit. The gas-filled conduit reduces the electrical charge and the speed of ablated ions as they collide and mix with buffer gases in the gas-filled conduit. Preferably, the gas filled-conduit includes an electromagnetic multipole structure that collimates the nascent ions into a beam, which is guided into the mass spectrometer. Because the gas-filled conduit allows storage of vast quantities of the ions from the ablated particles, the ions from a single ablated particle can be analyzed multiple times and by a variety of techniques to supply statistically meaningful analysis of composition and isotope ratios.

  6. Noninvasive real-time imaging of apoptosis.

    PubMed

    Laxman, Bharathi; Hall, Daniel E; Bhojani, Mahaveer Swaroop; Hamstra, Daniel A; Chenevert, Thomas L; Ross, Brian D; Rehemtulla, Alnawaz

    2002-12-24

    Strict coordination of proliferation and programmed cell death (apoptosis) is essential for normal physiology. An imbalance in these two opposing processes results in various diseases including AIDS, neurodegenerative disorders, myelodysplastic syndromes, ischemiareperfusion injury, cancer, autoimmune disease, among others. Objective and quantitative noninvasive imaging of apoptosis would be a significant advance for rapid and dynamic screening as well as validation of experimental therapeutic agents. Here, we report the development of a recombinant luciferase reporter molecule that when expressed in mammalian cells has attenuated levels of reporter activity. In cells undergoing apoptosis, a caspase-3-specific cleavage of the recombinant product occurs, resulting in the restoration of luciferase activity that can be detected in living animals with bioluminescence imaging. The ability to image apoptosis noninvasively and dynamically over time provides an opportunity for high-throughput screening of proapoptotic and antiapoptotic compounds and for target validation in vivo in both cell lines and transgenic animals. PMID:12475931

  7. Real time control for NASA robotic gripper

    NASA Technical Reports Server (NTRS)

    Salter, Carole A.; Baras, John S.

    1990-01-01

    The ability to easily manipulate objects in a zero gravity environment will pay a key role in future space activities. Emphasis will be placed on robotic manipulation. This will serve to increase astronaut safety and utility in addition to several other benefits. The aim is to develop control laws for the zero gravity robotic end effectors. A hybrid force/position controller will be used. Sensory data available to the controller are obtained from an array of strain gauges and a linear potentiometer. Applying well known optimal control theoretical principles, the control which minimizes the transition time between positions is obtained. A robust force control scheme is developed which allows the desired holding force to be achieved smoothly without oscillation. In addition, an algorithm is found to determine contact force and contact location.

  8. Two-electron Rabi oscillations in real-time time-dependent density-functional theory

    SciTech Connect

    Habenicht, Bradley F.; Tani, Noriyuki P.; Provorse, Makenzie R.; Isborn, Christine M.

    2014-11-14

    We investigate the Rabi oscillations of electrons excited by an applied electric field in several simple molecular systems using time-dependent configuration interaction (TDCI) and real-time time-dependent density-functional theory (RT-TDDFT) dynamics. While the TDCI simulations exhibit the expected single-electron Rabi oscillations at a single resonant electric field frequency, Rabi oscillations in the RT-TDDFT simulations are a two-electron process. The existence of two-electron Rabi oscillations is determined both by full population inversion between field-free molecular orbitals and the behavior of the instantaneous dipole moment during the simulations. Furthermore, the Rabi oscillations in RT-TDDFT are subject to an intensity threshold of the electric field, below which Rabi oscillations do not occur and above which the two-electron Rabi oscillations occur at a broad range of frequencies. It is also shown that at field intensities near the threshold intensity, the field frequency predicted to induce Rabi oscillations by linear response TDDFT only produces detuned Rabi oscillations. Instead, the field frequency that yields the full two-electron population inversion and Rabi oscillation behavior is shown to be the average of single-electron transition frequencies from the ground S{sub 0} state and the doubly-excited S{sub 2} state. The behavior of the two-electron Rabi oscillations is rationalized via two possible models. The first model is a multi-photon process that results from the electric field interacting with the three level system such that three level Rabi oscillations may occur. The second model suggests that the mean-field nature of RT-TDDFT induces paired electron propagation.

  9. Two-electron Rabi oscillations in real-time time-dependent density-functional theory.

    PubMed

    Habenicht, Bradley F; Tani, Noriyuki P; Provorse, Makenzie R; Isborn, Christine M

    2014-11-14

    We investigate the Rabi oscillations of electrons excited by an applied electric field in several simple molecular systems using time-dependent configuration interaction (TDCI) and real-time time-dependent density-functional theory (RT-TDDFT) dynamics. While the TDCI simulations exhibit the expected single-electron Rabi oscillations at a single resonant electric field frequency, Rabi oscillations in the RT-TDDFT simulations are a two-electron process. The existence of two-electron Rabi oscillations is determined both by full population inversion between field-free molecular orbitals and the behavior of the instantaneous dipole moment during the simulations. Furthermore, the Rabi oscillations in RT-TDDFT are subject to an intensity threshold of the electric field, below which Rabi oscillations do not occur and above which the two-electron Rabi oscillations occur at a broad range of frequencies. It is also shown that at field intensities near the threshold intensity, the field frequency predicted to induce Rabi oscillations by linear response TDDFT only produces detuned Rabi oscillations. Instead, the field frequency that yields the full two-electron population inversion and Rabi oscillation behavior is shown to be the average of single-electron transition frequencies from the ground S0 state and the doubly-excited S2 state. The behavior of the two-electron Rabi oscillations is rationalized via two possible models. The first model is a multi-photon process that results from the electric field interacting with the three level system such that three level Rabi oscillations may occur. The second model suggests that the mean-field nature of RT-TDDFT induces paired electron propagation. PMID:25399137

  10. Real-time and reliable human detection in clutter scene

    NASA Astrophysics Data System (ADS)

    Tan, Yumei; Luo, Xiaoshu; Xia, Haiying

    2013-10-01

    To solve the problem that traditional HOG approach for human detection can not achieve real-time detection due to its time-consuming detection, an efficient algorithm based on first segmentation then identify method for real-time human detection is proposed to achieve real-time human detection in clutter scene. Firstly, the ViBe algorithm is used to segment all possible human target regions quickly, and more accurate moving objects is obtained by using the YUV color space to eliminate the shadow; secondly, using the body geometry knowledge can help to found the valid human areas by screening the regions of interest; finally, linear support vector machine (SVM) classifier and HOG are applied to train for human body classifier, to achieve accurate positioning of human body's locations. The results of our comparative experiments demonstrated that the approach proposed can obtain high accuracy, good real-time performance and strong robustness.

  11. Real-time satellite monitoring of volcanic hot spots

    NASA Astrophysics Data System (ADS)

    Harris, Andrew J. L.; Flynn, Luke P.; Dean, Ken; Pilger, Eric; Wooster, Martin; Okubo, Chris; Mouginis-Mark, Peter; Garbeil, Harold; Thornber, Carl; De la Cruz-Reyna, Servando; Rothery, Dave; Wright, Robert

    Direct satellite data reception at high temporal frequencies and automated processing enable near-real-time, near-continuous thermal monitoring of volcanoes. We review what has been achieved in terms of turning this capability into real-time tools of use to volcano monitoring agencies. Current capabilities focus on 2 instruments: the advanced very high resolution radiometer (AVHRR) and the Geostationary Operational Environmental Satellite (GOES) imager. Collection of lO AVHRR images per day covering Alaska, the Aleutians, and Kamchatka allows routine, on-reception analysis of volcanic hot spots across this region. Data collected between 1996 and 1998 detected 302 hot spots due to lava flows, lava domes, pyroclastic flows, fumaroles, and geothermally heated lakes at 12 different volcanoes. Information was used for hazard mitigation by the Alaskan Volcano Observatory. GOES provides data for North and South American volcanoes every 15-30 minutes. Automated processing allows eruption information and alerts to be posted on the Internet within 15-60 minutes of reception. We use June 1998 to demonstrate the frequency of data acquisition. During this month 2879 GOES images were collected from which 14,832 sub-images of 6 active volcanoes were processed. Although 82% (12,200) of these sub-images were cloud covered, hot spots were still evident on 11% (1634) of the sub-images. Analysis of GOES data for 1998 identified hot spots due to (1) lava flows at Kilauea and Cerro Azul, (2) dome extrusion and explosive activity at Lascar, Popocatepetl, Colima and Pacaya, and (3) dome cooling and collapse at Soufriere Hills. We were also able to suggest that reports of lava flow activity at Cerro Negro were false. This information was supplied to, and used by, various agencies whose task it is to monitor these volcanoes. Global thermal monitoring will become a reality with the launch of the Earth Observing System's moderate resolution imaging spectrometer (MODIS). An automated thermal

  12. The short-time spectrum analysis of real-time sampling speech with DSP TMS320VC5416 chip

    NASA Astrophysics Data System (ADS)

    Fan, Qinru; Ren, Wen-hua

    2013-07-01

    For automatic speech recognition (ASR), the research centers mainly on algorithm of improving robust, researchers put less emphasis on realization and application of better speech algorithm. Real-time proceeding of speech recognition directly influence on its application, so real-time proceeding of speech recognition is as important as study of algorithm. Speech transform domain method is a necessary technique of speech recognition, so real-time analysis of transform domain method is necessary. In transform domain methods, the short-time spectrum analysis is simple and easy to realize, especially the short-time FFT algorithm is applied to the short-time spectrum analysis. FFT algorithm reduces multiplications greatly. For the purpose, this paper presents short-time spectrum analysis of real-time sampling speech based on FFT algorithm. We use DSP TMS320VC5416 chip and speech codec ASIC TLV320AIC23 as hardware, the real-time speech signal is acquired by ASIC TLV320AIC23. When working frequency of TMS320VC5416 is set 160 MHz and sampling frequency is 44.1 kHz, the short-time FFT is radix-2 DIF-FFT algorithm and the length of short-time window is 128, the simulation waves and data show that the short-time FFT algorithm analysis based on TMS320VC5416 chip can meet real-time of system. For estimation of proceeding error, we make a calculation of radix- 2 DIT-IFFT. Comparing the result of DIT-IFFT and sampling speech data, error is less than 10-3.

  13. Near real-time skin deformation mapping

    NASA Astrophysics Data System (ADS)

    Kacenjar, Steve; Chen, Suzie; Jafri, Madiha; Wall, Brian; Pedersen, Richard; Bezozo, Richard

    2013-02-01

    A novel in vivo approach is described that provides large area mapping of the mechanical properties of the skin in human patients. Such information is important in the understanding of skin health, cosmetic surgery[1], aging, and impacts of sun exposure. Currently, several methods have been developed to estimate the local biomechanical properties of the skin, including the use of a physical biopsy of local areas of the skin (in vitro methods) [2, 3, and 4], and also the use of non-invasive methods (in vivo) [5, 6, and 7]. All such methods examine localized areas of the skin. Our approach examines the local elastic properties via the generation of field displacement maps of the skin created using time-sequence imaging [9] with 2D digital imaging correlation (DIC) [10]. In this approach, large areas of the skin are reviewed rapidly, and skin displacement maps are generated showing the contour maps of skin deformation. These maps are then used to precisely register skin images for purposes of diagnostic comparison. This paper reports on our mapping and registration approach, and demonstrates its ability to accurately measure the skin deformation through a described nulling interpolation process. The result of local translational DIC alignment is compared using this interpolation process. The effectiveness of the approach is reported in terms of residual RMS, image entropy measures, and differential segmented regional errors.

  14. Real Time Observation of DNA Nanotube Assembly

    NASA Astrophysics Data System (ADS)

    Verde, Lisa Val

    2006-03-01

    DNA nanotubes are of interest for applications ranging from nanofabrication to biophysical studies. The DNA Nanotubes used in this research are self-assembling structures composed of DNA double-crossover tiles. These tiles are simply two connected helices composed of five single stranded DNA oligomers. Each tile exposes four sticky ends responsible for the linkage between neighboring tiles. This linkage creates the nanotube lattice, with intrinsic curvature. The curvature orients each tile with a 60^o angle from the previous one so that six tiles make up the circumference of a nanotube. Nanotube stability depends on conditions such as ionic strength and temperature. A PCR machine is used to anneal the strands into nanotubes. A duplicated annealing process was constructed under a light microscope. PVP (polyvinyl prolidone) coated glass both confined the DNA nanotubes to a 2-3 μm focal plane and prevented them from sticking to the sample surface. By the time the tubes were long enough to track (>= 3 μm), they continued to lengthen primarily via end-to-end joining with some reaching lengths greater than 100 μm. These observations helped define more efficient annealing protocols that resulted in tubes with fewer imperfections.

  15. Real time viability detection of bacterial spores

    DOEpatents

    Vanderberg, Laura A.; Herdendorf, Timothy J.; Obiso, Richard J.

    2003-07-29

    This invention relates to a process for detecting the presence of viable bacterial spores in a sample and to a spore detection system, the process including placing a sample in a germination medium for a period of time sufficient for commitment of any present viable bacterial spores to occur, mixing the sample with a solution of a lanthanide capable of forming a fluorescent complex with dipicolinic acid, and, measuring the sample for the presence of dipicolinic acid, and the system including a germination chamber having inlets from a sample chamber, a germinant chamber and a bleach chamber, the germination chamber further including an outlet through a filtering means, the outlet connected to a detection chamber, the detection chamber having an inlet from a fluorescence promoting metal chamber and the detection chamber including a spectral excitation source and a means of measuring emission spectra from a sample, the detection chamber further connected to a waste chamber. A germination reaction mixture useful for promoting commitment of any viable bacterial spores in a sample including a combination of L-alanine, L-asparagine and D-glucose is also described.

  16. Real-time feedback from iterative electronic structure calculations.

    PubMed

    Vaucher, Alain C; Haag, Moritz P; Reiher, Markus

    2016-04-01

    Real-time feedback from iterative electronic structure calculations requires to mediate between the inherently unpredictable execution times of the iterative algorithm used and the necessity to provide data in fixed and short time intervals for real-time rendering. We introduce the concept of a mediator as a component able to deal with infrequent and unpredictable reference data to generate reliable feedback. In the context of real-time quantum chemistry, the mediator takes the form of a surrogate potential that has the same local shape as the first-principles potential and can be evaluated efficiently to deliver atomic forces as real-time feedback. The surrogate potential is updated continuously by electronic structure calculations and guarantees to provide a reliable response to the operator for any molecular structure. To demonstrate the application of iterative electronic structure methods in real-time reactivity exploration, we implement self-consistent semiempirical methods as the data source and apply the surrogate-potential mediator to deliver reliable real-time feedback. © 2015 Wiley Periodicals, Inc. PMID:26678030

  17. Building flexible real-time systems using the Flex language

    NASA Technical Reports Server (NTRS)

    Kenny, Kevin B.; Lin, Kwei-Jay

    1991-01-01

    The design and implementation of a real-time programming language called Flex, which is a derivative of C++, are presented. It is shown how different types of timing requirements might be expressed and enforced in Flex, how they might be fulfilled in a flexible way using different program models, and how the programming environment can help in making binding and scheduling decisions. The timing constraint primitives in Flex are easy to use yet powerful enough to define both independent and relative timing constraints. Program models like imprecise computation and performance polymorphism can carry out flexible real-time programs. In addition, programmers can use a performance measurement tool that produces statistically correct timing models to predict the expected execution time of a program and to help make binding decisions. A real-time programming environment is also presented.

  18. Reference genes in real-time PCR.

    PubMed

    Kozera, Bartłomiej; Rapacz, Marcin

    2013-11-01

    This paper aims to discuss various aspects of the use of reference genes in qPCR technique used in the thousands of present studies. Most frequently, these are housekeeping genes and they must meet several criteria so that they can lay claim to the name. Lots of papers report that in different conditions, for different organisms and even tissues the basic assumption—the constant level of the expression is not maintained for many genes that seem to be perfect candidates. Moreover, their transcription can not be affected by experimental factors. Sounds simple and clear but a great number of designed protocols and lack of consistency among them brings confusion on how to perform experiment properly. Since during selection of the most stable normalizing gene we can not use any reference gene, different ways and algorithms for their selection were developed. Such methods, including examples of best normalizing genes in some specific cases and possible mistakes are presented based on available sources. Numerous examples of reference genes applications, which are usually in too few numbers in relevant articles not allowing to make a solid fundament for a reader, will be shown along with instructive compilations to make an evidence for presented statements and an arrangement of future qPCR experiments. To include all the pitfalls and problems associated with the normalization methods there is no way not to begin from sample preparation and its storage going through candidate gene selection, primer design and statistical analysis. This is important because numerous short reviews available cover the topic only in lesser extent at the same time giving the reader false conviction of complete topic recognition. PMID:24078518

  19. Real-time prediction of earthquake ground motion: time evolutional prediction using data assimilation and real-time correction of site amplification factors

    NASA Astrophysics Data System (ADS)

    Hoshiba, M.

    2012-12-01

    artificial network than the real one. Data assimilation is a powerful technique for time evolutional prediction. In seismology and earthquake engineering, however, site amplification factors should be corrected beforehand for applying the data assimilation. A method is proposed in which the frequency dependent site factor can be corrected in real time. The site factor is represented by the causal filter in time domain which is estimated from bilinear transform and warping methods in digital filtering technique. Using the causal filter, the site amplification factor is corrected in real time manner. Instead of rapid estimation of hypocentral location and M, time evolutional prediction is a powerful method for real-time prediction of ground motion for EEW, which is applicable even for cases of strong rupture directivity and large source extent. Techniques of data assimilation and real time correction of site amplification factors will be applied for the time evolutional prediction. An example of the real time correction of site factors is presented using data from borehole seismometer (depth: 500m) in the Kanto region.

  20. The First Real-Time Tsunami Animation

    NASA Astrophysics Data System (ADS)

    Becker, N. C.; Wang, D.; McCreery, C.; Weinstein, S.; Ward, B.

    2014-12-01

    For the first time a U.S. tsunami warning center created and issued a tsunami forecast model animation while the tsunami was still crossing an ocean. Pacific Tsunami Warning Center (PTWC) scientists had predicted they would have this ability (Becker et al., 2012) with their RIFT forecast model (Wang et al., 2009) by using rapidly-determined W-phase centroid-moment tensor earthquake focal mechanisms as tsunami sources in the RIFT model (Wang et al., 2012). PTWC then acquired its own YouTube channel in 2013 for its outreach efforts that showed animations of historic tsunamis (Becker et al., 2013), but could also be a platform for sharing future tsunami animations. The 8.2 Mw earthquake of 1 April 2014 prompted PTWC to issue official warnings for a dangerous tsunami in Chile, Peru and Ecuador. PTWC ended these warnings five hours later, then issued its new tsunami marine hazard product (i.e., no coastal evacuations) for the State of Hawaii. With the international warning canceled but with a domestic hazard still present PTWC generated a forecast model animation and uploaded it to its YouTube channel six hours before the arrival of the first waves in Hawaii. PTWC also gave copies of this animation to television reporters who in turn passed it on to their national broadcast networks. PTWC then created a version for NOAA's Science on a Sphere system so it could be shown on these exhibits as the tsunami was still crossing the Pacific Ocean. While it is difficult to determine how many people saw this animation since local, national, and international news networks showed it in their broadcasts, PTWC's YouTube channel provides some statistics. As of 1 August 2014 this animation has garnered more than 650,000 views. Previous animations, typically released during significant anniversaries, rarely get more than 10,000 views, and even then only when external websites share them. Clearly there is a high demand for a tsunami graphic that shows both the speed and the severity of a

  1. An Evaluation of Real-Time Zenith Total Delay Estimates

    NASA Astrophysics Data System (ADS)

    Ahmed, F.; Teferle, F. N.; Bingley, R.; Laurichesse, D.

    2012-12-01

    The use of modern low-latency Numerical Weather Prediction (NWP) models by meteorological institutions to improve nowcasting operations requires the accurate and timely estimation of the Zenith Total Delay (ZTD). Observations from Global Navigation Satellite Systems (GNSS) can be processed to obtain such ZTD estimates. As of now, meeting the established requirements on the latency (as low as 5 min) and accuracy (up to few millimeters) of the ZTD for its use in nowcasting applications stands as a challenge. However, using, for example, the real-time orbit and clock products from the recently established IGS Real-Time Service, it is possible to estimate the ZTD by different processing strategies and each strategy can result in a different level of accuracy. The Bundesamt für Kartographie und Geodäsie Ntrip Client (BNC) can provide ZTD estimates in real-time using precise point positioning (PPP) without integer ambiguity resolution. Recently, the Centre National d'Etudes Spatiales (CNES) has released a modified version of BNC which produces ZTD estimates in real-time with integer-PPP, i.e. PPP with integer ambiguity resolution using their integer-recovery clock and widelane phase bias information. trackRT from MIT and RTNet from GPS Solutions Inc are also capable of providing real-time estimates of the ZTD. In this study, we present an evaluation of the real-time ZTD estimates obtained from different GNSS processing systems. Furthermore, we compare the real-time estimates to those from a near real-time system and the IGS Final Troposphere products.

  2. Real-time modeling of transverse emittance growth due to ground motion

    SciTech Connect

    Shiltsev, V.D.; Parkhomchuk, V.V. |

    1993-09-01

    Ground motion noise at frequencies around 1 kHz causes growth of transverse emittance of the Superconducting Super Collider (SSC) collider beams. The effect was quantitatively investigated using real-time signals from seismometers installed at the tunnel depth and on the surface. The SSC beam was modeled as an ensemble of oscillators with a spread of betatron frequencies. The effect of transverse feedback on emittance growth was investigated.

  3. Head movement compensation in real-time magnetoencephalographic recordings

    PubMed Central

    Little, Graham; Boe, Shaun; Bardouille, Timothy

    2014-01-01

    Neurofeedback- and brain-computer interface (BCI)-based interventions can be implemented using real-time analysis of magnetoencephalographic (MEG) recordings. Head movement during MEG recordings, however, can lead to inaccurate estimates of brain activity, reducing the efficacy of the intervention. Most real-time applications in MEG have utilized analyses that do not correct for head movement. Effective means of correcting for head movement are needed to optimize the use of MEG in such applications. Here we provide preliminary validation of a novel analysis technique, real-time source estimation (rtSE), that measures head movement and generates corrected current source time course estimates in real-time. rtSE was applied while recording a calibrated phantom to determine phantom position localization accuracy and source amplitude estimation accuracy under stationary and moving conditions. Results were compared to off-line analysis methods to assess validity of the rtSE technique. The rtSE method allowed for accurate estimation of current source activity at the source-level in real-time, and accounted for movement of the source due to changes in phantom position. The rtSE technique requires modifications and specialized analysis of the following MEG work flow steps.•Data acquisition•Head position estimation•Source localization•Real-time source estimation This work explains the technical details and validates each of these steps. PMID:26150963

  4. Distributed real-time model-based diagnosis

    NASA Technical Reports Server (NTRS)

    Barrett, A. C.; Chung, S. H.

    2003-01-01

    This paper presents an approach to onboard anomaly diagnosis that combines the simplicity and real-time guarantee of a rule-based diagnosis system with the specification ease and coverage guarantees of a model-based diagnosis system.

  5. A multiprocessing architecture for real-time monitoring

    NASA Technical Reports Server (NTRS)

    Laffey, Thomas J.; Schmidt, James L.; Read, Jackson Y.; Kao, Simon M.

    1987-01-01

    A multiprocessing architecture for performing real time monitoring and analysis using knowledge-based problem solving techniques is discussed. To handle asynchronous inputs and perform in real time, the system consists of three or more separate processes which run concurrently on one or more processors and communicate via a message passing scheme. The Data Management Process gathers, compresses, scales and sends the incoming telemetry data to other tasks. The Inference Process consists of a proprietary high performance inference engine that runs at 1000 rules per second using telemetry data to perform real time analysis on the state and health of the Space Telescope. The multiprocessing architecture has been interfaced to a simulator and is able to process the incoming telemetry in real time.

  6. Real-time interactive speech technology at Threshold Technology, Incorporated

    NASA Technical Reports Server (NTRS)

    Herscher, Marvin B.

    1977-01-01

    Basic real-time isolated-word recognition techniques are reviewed. Industrial applications of voice technology are described in chronological order of their development. Future research efforts are also discussed.

  7. Real-time earthquake monitoring: Early warning and rapid response

    NASA Technical Reports Server (NTRS)

    1991-01-01

    A panel was established to investigate the subject of real-time earthquake monitoring (RTEM) and suggest recommendations on the feasibility of using a real-time earthquake warning system to mitigate earthquake damage in regions of the United States. The findings of the investigation and the related recommendations are described in this report. A brief review of existing real-time seismic systems is presented with particular emphasis given to the current California seismic networks. Specific applications of a real-time monitoring system are discussed along with issues related to system deployment and technical feasibility. In addition, several non-technical considerations are addressed including cost-benefit analysis, public perceptions, safety, and liability.

  8. Real-time holography on bacteriorhodopsin-based materials

    NASA Astrophysics Data System (ADS)

    Taranenko, Victor B.

    1998-09-01

    The main properties and mechanisms of photoresponse of the bacteriohodopsin-based materials are presented. Fields of their potential applications in the real-time holography and nonlinear optics are discussed.

  9. Cluster Computing for Embedded/Real-Time Systems

    NASA Technical Reports Server (NTRS)

    Katz, D.; Kepner, J.

    1999-01-01

    Embedded and real-time systems, like other computing systems, seek to maximize computing power for a given price, and thus can significantly benefit from the advancing capabilities of cluster computing.

  10. Intelligent data management for real-time spacecraft monitoring

    NASA Technical Reports Server (NTRS)

    Schwuttke, Ursula M.; Gasser, Les; Abramson, Bruce

    1992-01-01

    Real-time AI systems have begun to address the challenge of restructuring problem solving to meet real-time constraints by making key trade-offs that pursue less than optimal strategies with minimal impact on system goals. Several approaches for adapting to dynamic changes in system operating conditions are known. However, simultaneously adapting system decision criteria in a principled way has been difficult. Towards this end, a general technique for dynamically making such trade-offs using a combination of decision theory and domain knowledge has been developed. Multi-attribute utility theory (MAUT), a decision theoretic approach for making one-time decisions is discussed and dynamic trade-off evaluation is described as a knowledge-based extension of MAUT that is suitable for highly dynamic real-time environments, and provides an example of dynamic trade-off evaluation applied to a specific data management trade-off in a real-world spacecraft monitoring application.

  11. Hard-real-time resource management for autonomous spacecraft

    NASA Technical Reports Server (NTRS)

    Gat, E.

    2000-01-01

    This paper describes tickets, a computational mechanism for hard-real-time autonomous resource management. Autonomous spacecraftcontrol can be considered abstractly as a computational process whose outputs are spacecraft commands.

  12. Real-time data compression of broadcast video signals

    NASA Technical Reports Server (NTRS)

    Shalkauser, Mary Jo W. (Inventor); Whyte, Wayne A., Jr. (Inventor); Barnes, Scott P. (Inventor)

    1991-01-01

    A non-adaptive predictor, a nonuniform quantizer, and a multi-level Huffman coder are incorporated into a differential pulse code modulation system for coding and decoding broadcast video signals in real time.

  13. Real-time data compression of broadcast video signals

    NASA Technical Reports Server (NTRS)

    Shalkhauser, Mary J. (Inventor); Whyte, Wayne A., Jr. (Inventor); Barnes, Scott P. (Inventor)

    1990-01-01

    A non-adaptive predictor, a nonuniform quantizer, and a multi-level Huffman coder are incorporated into a differential pulse code modulation system for coding and decoding broadcast video signals in real time.

  14. The Effects of Real-Time Interactive Multimedia Teleradiology System

    PubMed Central

    Al-Safadi, Lilac

    2016-01-01

    This study describes the design of a real-time interactive multimedia teleradiology system and assesses how the system is used by referring physicians in point-of-care situations and supports or hinders aspects of physician-radiologist interaction. We developed a real-time multimedia teleradiology management system that automates the transfer of images and radiologists' reports and surveyed physicians to triangulate the findings and to verify the realism and results of the experiment. The web-based survey was delivered to 150 physicians from a range of specialties. The survey was completed by 72% of physicians. Data showed a correlation between rich interactivity, satisfaction, and effectiveness. The results of our experiments suggest that real-time multimedia teleradiology systems are valued by referring physicians and may have the potential for enhancing their practice and improving patient care and highlight the critical role of multimedia technologies to provide real-time multimode interactivity in current medical care. PMID:27294118

  15. Challenges of AVHRR Vegetation Data for Real Time Applications

    NASA Technical Reports Server (NTRS)

    Brown, Molly

    2008-01-01

    Remote sensing data has long been used to monitor global ecosystems for floods and droughts and AVHRR data, as one of the first product, has many users interested in receiving the data within hours of acquisition. With the introduction of a new series of sensors in 2000 (the AVHRR/3 series), the quality of the NDVI datasets available for real time environmental monitoring has declined. This paper provides evidence of problems of cloud contamination, calibration and noise in the real time data which are not present in the historical AVHRR NDVIg dataset. These differences introduce significant uncertainty in the use of the real time data, degrading their utility for detecting climate variations in near real time.

  16. Real-time prediction of seismic ground motion (I) : real-time estimation of seismic wavefield using data assimilation technique and time evolutional prediction using Kirchhoff integral

    NASA Astrophysics Data System (ADS)

    Hoshiba, M.

    2013-05-01

    also the prediction of one step before, P(u(x, t-Δt)). Combination of them produces denser artificial network than the real one. All past data as well as current observation are used for the estimation of current wavefield in the data assimilation technique. Estimation of current wavefield using data assimilation and time evolutional prediction (e.g., Kirchhoff integral) enables us to predict future ground motion precisely. In Part II, real-time correction of frequency dependent site amplification factors will be discussed.

  17. Evaluation of Open-Source Hard Real Time Software Packages

    NASA Technical Reports Server (NTRS)

    Mattei, Nicholas S.

    2004-01-01

    Reliable software is, at times, hard to find. No piece of software can be guaranteed to work in every situation that may arise during its use here at Glenn Research Center or in space. The job of the Software Assurance (SA) group in the Risk Management Office is to rigorously test the software in an effort to ensure it matches the contract specifications. In some cases the SA team also researches new alternatives for selected software packages. This testing and research is an integral part of the department of Safety and Mission Assurance. Real Time operation in reference to a computer system is a particular style of handing the timing and manner with which inputs and outputs are handled. A real time system executes these commands and appropriate processing within a defined timing constraint. Within this definition there are two other classifications of real time systems: hard and soft. A soft real time system is one in which if the particular timing constraints are not rigidly met there will be no critical results. On the other hand, a hard real time system is one in which if the timing constraints are not met the results could be catastrophic. An example of a soft real time system is a DVD decoder. If the particular piece of data from the input is not decoded and displayed to the screen at exactly the correct moment nothing critical will become of it, the user may not even notice it. However, a hard real time system is needed to control the timing of fuel injections or steering on the Space Shuttle; a delay of even a fraction of a second could be catastrophic in such a complex system. The current real time system employed by most NASA projects is Wind River's VxWorks operating system. This is a proprietary operating system that can be configured to work with many of NASA s needs and it provides very accurate and reliable hard real time performance. The down side is that since it is a proprietary operating system it is also costly to implement. The prospect of

  18. Electrical conductivity of metals from real-time time-dependent density functional theory

    NASA Astrophysics Data System (ADS)

    Andrade, Xavier; Correa, Alfredo

    In this presentation, I will discuss how to apply real-time electron dynamics to study electronic currents in crystalline systems and, in particular, how to use this method to predict electrical conductivities in different regimes. This approach presents many interesting theoretical challenges associated to the representation of bulk systems as infinitely periodic. For example, in order to induce electronic currents in the system, we use a gauge transformation that allows us to include finite electric fields in the simulation. We have implemented this approach using time-dependent density functional theory (TDDFT). This implementation allows us to induce, measure and visualize the current density as a function of time, in simulations with thousands of electrons (hundreds and even thousands of atoms). We have found that real-time TDDFT can describe how currents naturally decay in metals. From this dissipation process we can directly calculate the frequency-dependent conductivity, including the direct current (DC) conductivity that is not accessible from linear-response approaches like Kubo-Greenwood.

  19. High speed, real-time, camera bandwidth converter

    DOEpatents

    Bower, Dan E; Bloom, David A; Curry, James R

    2014-10-21

    Image data from a CMOS sensor with 10 bit resolution is reformatted in real time to allow the data to stream through communications equipment that is designed to transport data with 8 bit resolution. The incoming image data has 10 bit resolution. The communication equipment can transport image data with 8 bit resolution. Image data with 10 bit resolution is transmitted in real-time, without a frame delay, through the communication equipment by reformatting the image data.

  20. Real-time transesophageal echocardiography facilitates antegrade balloon aortic valvuloplasty

    PubMed Central

    Ito, Kazato; Yano, Kentaro; Tanaka, Chiharu; Nakashoji, Tomohiro; Tonomura, Daisuke; Takehara, Kosuke; Kino, Naoto; Yoshida, Masataka; Kurotobi, Toshiya; Tsuchida, Takao; Fukumoto, Hitoshi

    2016-01-01

    We report two cases of severe aortic stenosis (AS) where antegrade balloon aortic valvuloplasty (BAV) was performed under real-time transesophageal echocardiography (TEE) guidance. Real-time TEE can provide useful information for evaluating the aortic valve response to valvuloplasty during the procedure. It was led with the intentional wire-bias technique in order to compress the severely calcified leaflet, and consequently allowed the balloon to reach the largest possible size and achieve full expansion of the aortic annulus. PMID:27054107

  1. Real time simulator with Ti floating point digital signal processor

    SciTech Connect

    Razazian, K.; Bobis, J.P.; Dieckman, S.L.; Raptis, A.C.

    1994-08-01

    This paper describes the design and operation of a Real Time Simulator using Texas Instruments TMS320C30 digital signal processor. This system operates with two banks of memory which provide the input data to digital signal processor chip. This feature enables the TMS320C30 to be utilized in variety of applications for which external connections to acquire input data is not needed. In addition, some practical applications of this Real Time Simulator are discussed.

  2. Real-time shipboard orbit determination using Kalman filtering techniques

    NASA Technical Reports Server (NTRS)

    Brammer, R. F.

    1974-01-01

    The real-time tracking and orbit determination program used on board the NASA tracking ship, the USNS Vanguard, is described in this paper. The computer program uses a variety of filtering algorithms, including an extended Kalman filter, to derive real-time orbit determinations (position-velocity state vectors) from shipboard tracking and navigation data. Results from Apollo missions are given to show that orbital parameters can be estimated quickly and accurately using these methods.

  3. Real-time flight test data distribution and display

    NASA Technical Reports Server (NTRS)

    Nesel, Michael C.; Hammons, Kevin R.

    1988-01-01

    Enhancements to the real-time processing and display systems of the NASA Western Aeronautical Test Range are described. Display processing has been moved out of the telemetry and radar acquisition processing systems super-minicomputers into user/client interactive graphic workstations. Real-time data is provided to the workstations by way of Ethernet. Future enhancement plans include use of fiber optic cable to replace the Ethernet.

  4. Real-Time Optical Correlator Based On GaAs

    NASA Technical Reports Server (NTRS)

    Liu, Tsuen-Hsi; Cheng, Li-Jen

    1992-01-01

    Apparatus performs correlation between input image and reference image in real time by means of degenerate four-wave mixing in photorefractive crystal, which serves as real-time holographic medium. Gallium arsenide chosen to be photorefractive material in this application because at frame rate and level of illumination used in experiments, offers adequate diffraction efficiency. Frame rates as high as 1,000 s to negative 1st power achievable.

  5. Real-time laser holographic Interferometry for aerodynamics

    NASA Technical Reports Server (NTRS)

    Lee, George

    1987-01-01

    Recent developments in thermoplastic recording holograms and advancements in automated image digitalization and analysis make real-time laser holographic interferometry feasible for two-dimensional flows such as airfoil flows. Typical airfoil measurements would include airfoil presssure distributions, wake and boundary layer profiles, and flow field density contours. This paper addresses some of the problems and requirements of a real-time laser holographic interferometer.

  6. Real-time laser holographic interferometry for aerodynamics

    NASA Technical Reports Server (NTRS)

    Lee, George

    1987-01-01

    Recent developments in thermoplastic recording holograms and advancements in automated image digitalization and analysis make real-time laser holographic interferometry feasible for two-dimensional flows such as airfoil flows. Typical airfoil measurements would include airfoil pressure distributions, wake and boundary layer profiles, and flow field density contours. This paper addresses some of the problems and requirements of a real-time laser holographic interferometer.

  7. Enhancement of EarthScope Infrastructure with Real Time Seismogeodesy

    NASA Astrophysics Data System (ADS)

    Bock, Y.; Melgar, D.; Geng, J.; Haase, J. S.; Crowell, B. W.; Squibb, M. B.

    2013-12-01

    Recent great earthquakes and ensuing tsunamis in Sumatra, Chile and Japan have demonstrated the need for accurate ground displacements that fully characterize the great amplitudes and broad dynamic range of motions associated with these complex ruptures. Our ability to model the source processes of these events and their effects, whether in real-time or after the fact, is limited by the weaknesses of both seismic and geodetic networks. Geodetic instruments provide the static component as well as coarse dynamic motions but are much less precise than seismic instruments, especially in the vertical direction. Seismic instruments provide exceptionally-sensitive dynamic motions but typically have difficulty in recovering unbiased near-field low-frequency absolute displacements. We have shown in several publications that an optimal combination of data from collocated GPS and strong motion accelerometers provides seismogeodetic displacement, velocity and point tilt waveforms spanning the full spectrum of seismic motion, without clipping and magnitude saturation. These observations are suitable for earthquake early warning (EEW) through detection of P wave arrivals, rapid assessment of earthquake magnitude, finite-source centroid moment tensor solutions and fault slip models, and tsunami warning, in particular in the near-source regions of large earthquakes. At present, more than 550 real-time GPS stations are operating in Western North America, a majority as part of the EarthScope/PBO effort with a concentration in the Cascadia region and southern California. Unfortunately, there are few collocations of GPS and accelerometers in this region (the exception being in parts of the BARD network in northern California). We have leveraged the considerable infrastructure already invested in the EarthScope project, and funding through NSF and NASA to create advanced software, hardware, and algorithms that make it possible to utilize EarthScope/PBO as an EEW test bed. We have

  8. DSN radio science system Mark III-78 real-time display capability

    NASA Technical Reports Server (NTRS)

    Berman, A. L.

    1977-01-01

    The current plane to provide radio science real-time display capability in response to multimission radio science requirements is described. Topics discussed include the display of Doppler frequency and high-resolution graphical display of all closed-loop radio metric parameters, and spectrum displays of open-loop receiver output.

  9. Real-time airborne hyperspectral imaging of land mines

    NASA Astrophysics Data System (ADS)

    Ivanco, Tyler; Achal, Steve; McFee, John E.; Anger, Cliff; Young, Jane

    2007-04-01

    DRDC Suffeld and Itres Research have jointly investigated the use of visible and infrared hyperspectral imaging (HSI) for surface and buried land mine detection since 1989. These studies have demonstrated reliable passive HSI detection of surface-laid mines, based on their reflectance spectra, from airborne and ground-based platforms. Commercial HSI instruments collect and store image data at aircraft speeds, but the data are analysed off- line. This is useful for humanitarian demining, but unacceptable for military countermine operations. We have developed a hardware and software system with algorithms that can process the raw hyperspectral data in real time to detect mines. The custom algorithms perform radiometric correction of the raw data, then classify pixels of the corrected data, referencing a spectral signature library. The classification results are stored and displayed in real time, that is, within a few frame times of the data acquisition. Such real-time mine detection was demonstrated for the first time from a slowly moving land vehicle in March 2000. This paper describes an improved system which can achieve real-time detection of mines from an airborne platform, with its commensurately higher data rates. The system is presently compatible with the Itres family of visible/near infrared, short wave infrared and thermal infrared pushbroom hyperspectral imagers and its broadband thermal infrared pushbroom imager. Experiments to detect mines from an airborne platform in real time were conducted at DRDC Suffield in November 2006. Surface-laid land mines were detected in real time from a slowly moving helicopter with generally good detection rates and low false alarm rates. To the authors' knowledge, this is the first time that land mines have been detected from an airborne platform in real time using hyperspectral imaging.

  10. A Formal Model for Real-Time Parallel Computation

    SciTech Connect

    Hui, Peter SY; Chikkagoudar, Satish

    2012-12-29

    The imposition of real-time constraints on a parallel computing environment--- specifically high-performance, cluster-computing systems--- introduces a variety of challenges with respect to the formal verification of the system's timing properties. In this paper, we briefly motivate the need for such a system, and we introduce an automaton-based method for performing such formal verification. We define the concept of a consistent parallel timing system: a hybrid system consisting of a set of timed automata (specifically, timed Buechi automata as well as a timed variant of standard finite automata), intended to model the timing properties of a well-behaved real-time parallel system. Finally, we give a brief case study to demonstrate the concepts in the paper: a parallel matrix multiplication kernel which operates within provable upper time bounds. We give the algorithm used, a corresponding consistent parallel timing system, and empirical results showing that the system operates under the specified timing constraints.

  11. Real-time beyond the horizon vessel detection

    NASA Astrophysics Data System (ADS)

    Roarty, Hugh J.; Smith, Michael; Glenn, Scott M.; Barrick, Donald E.

    2013-05-01

    The marine transportation system (MTS) is a vital component of the United States Economy. Waterborne cargo accounts for more than $742 billion of the nation's economy and creates employment for 13 million citizens. A disruption in this system would have far reaching consequences to the security of the country. The US National High Frequency radar network, which comprises 130 radar stations around the country, became operational in May 2009. It provides hourly measurements of surface currents to the US Coast Guard for search and rescue (SAR). This system has the capability of being a dual use system providing information for environmental monitoring as well as vessel position information for maritime security. Real time vessel detection has been implemented at two of the radar stations outside New York Harbor. Several experiments were conducted to see the amount vessel traffic that the radar could capture. The radars were able to detect a majority of the vessels that are reporting via the Automatic Identification System (AIS) as well as 30 percent of mid to large size vessels that are not reporting via AIS. The radars were able to detect vessels out to 60 km from the coast. The addition of a vessel detection capability to the National HF radar network will provide valuable information to maritime security sector. This dual use capability will fill a gap in the current surveillance of US coastal waters. It will also provide longer-range situational awareness necessary to detect and track smaller size vessels in the large vessel clutter.

  12. Real time dynamic behavior of vertex frustrated artificial spin ice

    NASA Astrophysics Data System (ADS)

    Lao, Yuyang; Sklenar, Joseph; Gilbert, Ian; Carrasquilo, Isaac; Scholl, Andreas; Young, Anthony; Nisoli, Cristiano; Schiffer, Peter

    Artificial spin ice systems comprise two dimensional arrays of nanoscale single domain ferromagnets designed to have frustrated interactions among the moments. By decimating islands from the common square artificial spin ice, one can design lattices with so called `vertex frustration'. In such lattices, the geometry prevents all vertices from occupying local ground states simultaneously. Using Photoemission Electron Microscopy (PEEM), we access the real time thermally induced dynamics of the moment behavior in those lattices. Operating at a proper temperature, the moment direction of each island fluctuates with a sufficiently slow frequency that it can be resolvable by acquiring successive PEEM images. We can extract information regarding the collective excitations of the moments and understand how they reflect the frustration of lattice. Supported by the US Department of Energy, Office of Basic Energy Sciences, Materials Science and Engineering Division under Grant No. DE-SC0010778. The work of C.N. was carried out under the auspices of the US Department of Energy at LANL under Contract no. DE-AC52-06NA253962. The ALS is supported by the Director, Office of Science, Office of Basic Energy Sciences, of the US Department of Energy under Contract no. DE-AC02-05CH11231.

  13. HF channel modeling for real-time packet transmission

    NASA Astrophysics Data System (ADS)

    Rostami, Mehdi; Angeja, Joao; Tavares, Joao; Navarro, Antonio

    2003-07-01

    The recent rapid growth of multimedia communications has efficiently allowed delivering different services, formats and contents over an enormous variety of digital networks with IP acting as an integration protocol. The main objective of this research work is to evaluate the performance of an high frequency (HF) wireless network for transporting multimedia services according to UDP/IP protocol stack. Besides, allowing civil/amateur communications, HF bands are also used for long distance wireless military communications. Therefore, our work is based on NATO Link and Physical layer standards, STANAG 5066 and STANAG 4539, respectively. A typical transmission bandwidth is about 3 kHz resulting in a varying bit rate in the range between 75 and 12800 bps. This very low bit rate by itself imposes serious challenges for reliable real time multimedia communications. This paper discusses optimal combinations of channel coders, modulators and packet sizes in order to achieve the greatest throughput in function of the signal-to-noise ratio and HF channel conditions.

  14. Real-time Responsiveness for Ethics Oversight During Disaster Research.

    PubMed

    Eckenwiler, Lisa; Pringle, John; Boulanger, Renaud; Hunt, Matthew

    2015-11-01

    Disaster research has grown in scope and frequency. Research in the wake of disasters and during humanitarian crises--particularly in resource-poor settings--is likely to raise profound and unique ethical challenges for local communities, crisis responders, researchers, and research ethics committees (RECs). Given the ethical challenges, many have questioned how best to provide research ethics review and oversight. We contribute to the conversation concerning how best to ensure appropriate ethical oversight in disaster research and argue that ethical disaster research requires of researchers and RECs a particular sort of ongoing, critical engagement which may not be warranted in less exceptional research. We present two cases that typify the concerns disaster researchers and RECs may confront, and elaborate upon what this ongoing engagement might look like--how it might be conceptualized and utilized--using the concept of real-time responsiveness (RTR). The central aim of RTR, understood here as both an ethical ideal and practice, is to lessen the potential for research conducted in the wake of disasters to create, perpetuate, or exacerbate vulnerabilities and contribute to injustices suffered by disaster-affected populations. Well cultivated and deployed, we believe that RTR may enhance the moral capacities of researchers and REC members, and RECs as institutions where moral agency is nurtured and sustained. PMID:26481207

  15. A Scheduling Algorithm for Replicated Real-Time Tasks

    NASA Technical Reports Server (NTRS)

    Yu, Albert C.; Lin, Kwei-Jay

    1991-01-01

    We present an algorithm for scheduling real-time periodic tasks on a multiprocessor system under fault-tolerant requirement. Our approach incorporates both the redundancy and masking technique and the imprecise computation model. Since the tasks in hard real-time systems have stringent timing constraints, the redundancy and masking technique are more appropriate than the rollback techniques which usually require extra time for error recovery. The imprecise computation model provides flexible functionality by trading off the quality of the result produced by a task with the amount of processing time required to produce it. It therefore permits the performance of a real-time system to degrade gracefully. We evaluate the algorithm by stochastic analysis and Monte Carlo simulations. The results show that the algorithm is resilient under hardware failures.

  16. Explaining How to Play Real-Time Strategy Games

    NASA Astrophysics Data System (ADS)

    Metoyer, Ronald; Stumpf, Simone; Neumann, Christoph; Dodge, Jonathan; Cao, Jill; Schnabel, Aaron

    Real-time strategy games share many aspects with real situations in domains such as battle planning, air traffic control, and emergency response team management which makes them appealing test-beds for Artificial Intelligence (AI) and machine learning. End user annotations could help to provide supplemental information for learning algorithms, especially when training data is sparse. This paper presents a formative study to uncover how experienced users explain game play in real-time strategy games. We report the results of our analysis of explanations and discuss their characteristics that could support the design of systems for use by experienced real-time strategy game users in specifying or annotating strategy-oriented behavior.

  17. Robust Blind Frequency and Transition Time Estimation for Frequency Hopping Systems

    NASA Astrophysics Data System (ADS)

    Fu, Kuo-Ching; Chen, Yung-Fang

    2010-12-01

    In frequency hopping spread spectrum (FHSS) systems, two major problems are timing synchronization and frequency estimation. A blind estimation scheme is presented for estimating frequency and transition time without using reference signals. The scheme is robust in the sense that it can avoid the unbalanced sampling block problem that occurs in existing maximum likelihood-based schemes, which causes large errors in one of the estimates of frequency. The proposed scheme has a lower computational cost than the maximum likelihood-based greedy search method. The estimated parameters are also used for the subsequent time and frequency tracking. The simulation results demonstrate the efficacy of the proposed approach.

  18. Real-time drought forecasting system for irrigation management

    NASA Astrophysics Data System (ADS)

    Ceppi, A.; Ravazzani, G.; Corbari, C.; Salerno, R.; Meucci, S.; Mancini, M.

    2014-09-01

    In recent years frequent periods of water scarcity have enhanced the need to use water more carefully, even in European areas which traditionally have an abundant supply of water, such as the Po Valley in northern Italy. In dry periods, water shortage problems can be enhanced by conflicting uses of water, such as irrigation, industry and power production (hydroelectric and thermoelectric). Furthermore, in the last decade the social perspective in relation to this issue has been increasing due to the possible impact of climate change and global warming scenarios which emerge from the IPCC Fifth Assessment Report (IPCC, 2013). Hence, the increased frequency of drought periods has stimulated the improvement of irrigation and water management. In this study we show the development and implementation of the PREGI real-time drought forecasting system; PREGI is an Italian acronym that means "hydro-meteorological forecast for irrigation management". The system, planned as a tool for irrigation optimization, is based on meteorological ensemble forecasts (20 members) at medium range (30 days) coupled with hydrological simulations of water balance to forecast the soil water content on a maize field in the Muzza Bassa Lodigiana (MBL) consortium in northern Italy. The hydrological model was validated against measurements of latent heat flux acquired by an eddy-covariance station, and soil moisture measured by TDR (time domain reflectivity) probes; the reliability of this forecasting system and its benefits were assessed in the 2012 growing season. The results obtained show how the proposed drought forecasting system is able to have a high reliability of forecast at least for 7-10 days ahead of time.

  19. Real-Time Data Use for Operational Space Weather Products

    NASA Astrophysics Data System (ADS)

    Quigley, S.; Nobis, T. E.

    2010-12-01

    The Space Vehicles Directorate of the Air Force Research Laboratory (AFRL/RVBX) and the Space Environment Division of the Space and Missile Systems Center (AFSPC SYAG/WMLE) have combined efforts to design, develop, test, implement, and validate numerical and graphical products for Air Force Space Command’s (AFSPC) Space Environmental Effects Fusion System (SEEFS). These products were developed to analyze, specify, and forecast the effects of the near-earth space environment on Department of Defense weapons, navigation, communications, and surveillance systems in real/near-real time. This real-time attribute is the primary factor in allowing for actual operational product output, but it’s also responsible for a variety of detrimental effects that need to be considered, researched, mitigated, or otherwise eliminated in future/upgrade product applications. This presentation will provide brief overviews of the SEEFS products, along with information and recommendations concerned with their near/real-time data acquisition and use, to include: input data requirements, inputs/outputs ownership, observation cadence, transmission/receipt links and cadence, data latency, quality control, error propagation and associated confidence level applications, and ensemble model run potentials. Validation issues related to real-time data will also be addressed, along with recommendations for new real-time data archiving that should prove operationally beneficial.

  20. Distributing Frequency And Time Signals On Optical Fibers

    NASA Technical Reports Server (NTRS)

    Lutes, George F.

    1993-01-01

    Paper reports progress in distribution of frequency and time reference signals over optical fibers. Describes current performance at frequencies of 100 MHz, 1 GHz, and 8.4 GHz. Also describes transmitting and receiving equipment and discusses tradeoff between cost and performance. Concludes with discussion of likely future development and effects of developments on systems using distributed frequency reference signals.