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Large Signal RF Measurement Systems and Implementation of a Tuned Receiver SystemAzhar, Ahsan January 2008 (has links)
<p><p>This report shows a survey of sate of the art different large signal RF measurement systems. Such measurement systems are discussed in detail with respect to their architecture, method of measurement, calibration, accuracy, dynamic range and bandwidth. Finally, a RF measurement system for large signal was designed and implemented. This measurement system was based on a tuned receiver. Harmonic distortion type measurements were taken by this system and time domain waveforms were reconstructed using external software.</p></p>
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Receiver Function Analysis and Acoustic Waveform Modeling for Imaging Earth’s Crust: New Techniques and Their ApplicationsLiu, Huafeng 16 September 2013 (has links)
The crust is the outer-most layer of the earth with thickness up to 80 km. Massive seismic waveform data have enabled imaging fine crustal structures with the aid of new imaging techniques. In this thesis, I develop seismic imaging techniques to take full advantage of the expanding dataset as well as apply the imaging techniques to understand crustal seismic structures. First, I apply receiver function techniques to image the crustal thickness and average Vp/Vs in Northeast China. I found an uplifted Moho in eastern flank of the Songliao Basin and the Changbaishan region and suggest that dynamic mantle upwelling might be the cause of the observed uplift. With accumulated waveform data available, it becomes possible to extract more subtle structural information from receiver function. Second, I develop a new technique to robustly estimate seismic azimuthal anisotropy with radial and transverse receiver functions. I apply this technique to estimate the crustal anisotropy in Southeast Yunnan region and found that the significant crustal anisotropy may be caused by lower crust flow in this region. Full-wave based imaging techniques such as reverse time migration and full-wave inversion does not assume flat interfaces or infinite frequency rays as that the receiver function techniques do and are desirable in imaging more complex crustal structures. However, their high computational cost is one of the issues that prevent their practical applications. In the last part, I developed an effective waveform modeling technique to efficiently simulate wave propagation in acoustic media. With this novel modeling technique, the full-wave based imaging techniques are accelerated by a factor up to 400%.
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Large Signal RF Measurement Systems and Implementation of a Tuned Receiver SystemAzhar, Ahsan January 2008 (has links)
This report shows a survey of sate of the art different large signal RF measurement systems. Such measurement systems are discussed in detail with respect to their architecture, method of measurement, calibration, accuracy, dynamic range and bandwidth. Finally, a RF measurement system for large signal was designed and implemented. This measurement system was based on a tuned receiver. Harmonic distortion type measurements were taken by this system and time domain waveforms were reconstructed using external software.
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Digitally Assisted Multi-Channel ReceiversPentakota, Krishna Anand Santosh Spikanth 2010 August 1900 (has links)
This work presents a data estimation scheme for wide band multi-channel charge
sampling receivers with sinc filter banks together with a complete system calibration and
synchronization algorithm for the receiver. A unified model has been defined for the
receiver containing all first order mismatches, offsets and imperfections and a technique
based on least mean squares algorithm is employed to track these errors. The performance
of this technique under noisy channel conditions has been verified. The sinc filter bank is
compared with the conventional analog filter banks and it is shown that the sinc filter banks
have very low computational complexity in data estimation
Nextly, analytical tools for the design of clock-jitter tolerant multi-channel filterbank
receivers have been developed. Clock-jitter is one of the most fundamental obstacles
for the future generation of wideband receivers. Additionally all the trade-offs and
specifications of a design example for a multi-channel receiver that can process a 5 GHz
baseband signal with 40 dB of signal-to-noise-ratio (SNR) using sampling clocks that can
tolerate up to 5 ps of clock-jitter standard deviation are presented. A novel bandwidth
optimization technique has been presented. As a part of it the bandwidth of the filters present in each path is optimized thereby improving the performance of the receiver further
in the presence of sampling clock jitter. The amount of bandwidth reduction possible
depends on the order of the filter and the noise amplification provided by the reconstruction
matrix. It has been shown that 3rd order filters of bandwidth 1 GHz can be replaced with 1st
order filters of bandwidth 100 MHz without any depreciation in the output resolution,
implying huge power savings.
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Design and Implementation of Multi-function Monitoring Control SystemChung, Hung-Rung 30 July 2001 (has links)
This paper designs and implements a DSP based Multi-function Monitoring Control System, operate for induction motor, intelligent battery charger and residual capacity estimator and Uninterrupt Power System to develop effectively and complete well. This paper that Multi-function Monitoring Control System set up RS-232 standard, to use Asynchronous Receiver Transmitter Communication, to use DSP software refinement, to solve using ¡§8250¡¨ that Communication IC complete PC and DSP Communication generally. And DSP software monitor and control that induction motor, intelligent battery charger and residual capacity estimator and Uninterrupt Power System well. Monitoring control system utilize DSP operate very fast¡Aso DSP software function to supply hardware work¡Ato reduce prime cost.
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Evaluation of intelligent medical systemsTilbury, Julian Bernard January 2002 (has links)
This thesis presents novel, robust, analytic and algorithmic methods for calculating Bayesian posterior intervals of receiver operating characteristic (ROC) curves and confusion matrices used for the evaluation of intelligent medical systems tested with small amounts of data. Intelligent medical systems are potentially important in encapsulating rare and valuable medical expertise and making it more widely available. The evaluation of intelligent medical systems must make sure that such systems are safe and cost effective. To ensure systems are safe and perform at expert level they must be tested against human experts. Human experts are rare and busy which often severely restricts the number of test cases that may be used for comparison. The performance of expert human or machine can be represented objectively by ROC curves or confusion matrices. ROC curves and confusion matrices are complex representations and it is sometimes convenient to summarise them as a single value. In the case of ROC curves, this is given as the Area Under the Curve (AUC), and for confusion matrices by kappa, or weighted kappa statistics. While there is extensive literature on the statistics of ROC curves and confusion matrices they are not applicable to the measurement of intelligent systems when tested with small data samples, particularly when the AUC or kappa statistic is high. A fundamental Bayesian study has been carried out, and new methods devised, to provide better statistical measures for ROC curves and confusion matrices at low sample sizes. They enable exact Bayesian posterior intervals to be produced for: (1) the individual points on a ROC curve; (2) comparison between matching points on two uncorrelated curves; . (3) the AUC of a ROC curve, using both parametric and nonparametric assumptions; (4) the parameters of a parametric ROC curve; and (5) the weight of a weighted confusion matrix. These new methods have been implemented in software to provide a powerful and accurate tool for developers and evaluators of intelligent medical systems in particular, and to a much wider audience using ROC curves and confusion matrices in general. This should enhance the ability to prove intelligent medical systems safe and effective and should lead to their widespread deployment. The mathematical and computational methods developed in this thesis should also provide the basis for future research into determination of posterior intervals for other statistics at small sample sizes.
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Improvement of MR Images Using a Wireless Axial Pair ResonatorTOYOOKA, Nobuo, ANDO, Yoko, MAEDA, Hisatoshi 10 1900 (has links)
No description available.
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Design and Evaluation of a Discrete Wavelet Transform Based Multi-Signal ReceiverChiang, Tony 11 July 2006 (has links)
No description available.
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Circuit design for low voltage wireless receiver with improved image rejectionYounus, Md Iqbal 12 October 2004 (has links)
No description available.
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Design of Ultrawideband Digitizing Receivers for the VHF Low BandTaylor, David Wyatt 24 July 2006 (has links)
The next generation of receivers for applications such as radio astronomy, spectrum surveillance, and frequency-adaptive cognitive radio will require the capability to digitize very large bandwidths in the VHF low band (30 to 100 MHz). However, methodology for designing such a receiver is not well established. The difficulties of this design are numerous. There are various man-made interferers occupying this spectrum which can block desired signals or spectrum, either directly or through intermodulation. The receivers will typically use simple (i.e., narrowband) antennas, so the efficiency of power transfer to the preamplifier needs to be carefully considered. This thesis takes these design challenges into account and produces a seven step design methodology for direct sampling wideband digitizing receivers. The methodology is then demonstrated by example for three representative receivers. Finally, improvements to the analysis are suggested. / Master of Science
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