Bibliography: leaves 287-294. This thesis addresses preprocessing issues for radar target classification from high resolution radar imagery. High resolution radar imagery of real aircraft in flight and of a MIRAGE aircraft on a turntable is examined. An algorithm to coherently average high resolution range profile is proposed.

<p>Today, a high noise level is considered a problem in many working environments. The main reason is that it contributes to stress and fatigue. Traditional methods using passive noise control is only practicable for high frequencies. As a complement to passive noise control, active noise control (ANC) can be used to reduce low frequency noise. The main idea of ANC is to use destructive interference of waves to cancel disturbing noises.</p><p>The purpose of this thesis is to design and implement an ANC system in the driver's cabin of a Valmet 890 forest</p><p>machine. The engine boom is one of the most disturbing noises and therefore the main subjective for the ANC system to suppress.</p><p>The ANC system is implemented on a Texas Instrument DSP development starter kit. Different FxLMS algorithms are evaluated with feedback and feedforward configurations.</p><p>The results indicate that an ANC system significantly reduces the sound pressure level (SPL) in the cabin. Best performance of the evaluated systems is achieved for the feedforward FxLMS system. For a commonly used engine speed of 1500 rpm, the SPL is reduced with 17 dB. The results show fast enough convergence and global suppression of low frequency noise.</p>

<p>This thesis presents a study of alternative speech feature extraction methods aimed at increasing robustness of automatic speech recognition (ASR) against additive background noise. </p><p>Spectral peak positions of speech signals remain practically unchanged in presence of additive background noise. Thus, it was expected that emphasizing spectral peak positions in speech feature extraction would result in improved noise robustness of ASR systems. If frequency subbands are properly chosen, dominant subband frequencies can serve as reasonable estimates of spectral peak positions. Thus, different methods for incorporating dominant subband frequencies into speech feature vectors were investigated in this study.</p><p>To begin with, two earlier proposed feature extraction methods that utilize dominant subband frequency information were examined. The first one uses zero-crossing statistics of the subband signals to estimate dominant subband frequencies, while the second one uses subband spectral centroids. The methods were compared with the standard MFCC feature extraction method on two different recognition tasks in various background conditions. The first method was shown to improve ASR performance on both recognition tasks at sufficiently high noise levels. The improvement was, however, smaller on the more complex recognition task. The second method, on the other hand, led to some reduction in ASR performance in all testing conditions.</p><p>Next, a new method for incorporating subband spectral centroids into speech feature vectors was proposed, and was shown to be considerably more robust than the standard MFCC method on both ASR tasks. The main difference between the proposed method and the zero-crossing based method is in the way they utilize dominant subband frequency information. It was shown that the performance improvement due to the use of dominant subband frequency information was considerably larger for the proposed method than for the ZCPA method, especially on the more complex recognition task. Finally, the computational complexity of the proposed method is two orders of magnitude lower than that of the zero-crossing based method, and of the same order of magnitude as the standard MFCC method.</p>

Rethinking the Dualism: Don DeLillo's White Noise and the Ecocritical Possibilities of the Nature/Culture Mix questions current applications of ecocriticism and offers that these applications are inadequate in dealing with the perceived nature/culture dualism. This thesis suggests that ecocritics need to stop thinking in dualistic terms, but instead must consider that the separation between nature and culture is an illusion created by the postmodern culture. Don DeLillo's White Noise, then, is used to illustrate the possibilities of rethinking the relationship between nature and culture. DeLillo exposes the illusion of the dualism by constantly implicating humans in the alteration of nature and, despite humans' attempts to live within the illusory dualism by controlling nature through tecimology, by revealing that man's efforts will always fail through unintended consequences. This thesis culminates by proposing that considering nature and culture as connected entities that constantly reshape each other will absorb dualistic thinking and provide opportunities for ecocritics to expose truths that are vital to fueling the desire to alter destructive relationships between nature and culture. / Graduation date: 2004

Graduation date: 2001

This thesis presents a systematic top-down methodology for simulating a phase-locked loop using a macro model in Verilog-A. The macromodel has been used to evaluate the jitter due to supply noise, thermal noise, and ground bounce. The noise simulation with the behavioral model is roughly 310 times faster (best case) and 125 times faster (worst case). The accuracy of the model depends on the accurate evaluation of the non-linear transfer function from the various noisy nodes to the output. By modeling the noise transfer function of the circuit as closely as possible, 100% accuracy for the behavioral noise simulations compared with the HSPICE noise simulations is obtained. The macro model is written for a charge-pump phase-locked loop, but can be easily extended to other architectures. The simulations are completed using SpectreS in Cadence. The designer can use the model to estimate the jitter at the output of the PLL in a top-down design methodology or cross verify the performance of an existing chip in a bottom-up approach. / Graduation date: 2001

Alfred Zacharias, Louis D. Smullin. / Based on a thesis, M.I.T. Dept. of Electrical Engineering, May 25, 1959. / Bibliography: p. 23. / Army Signal Corps Contract DA36-039-sc-78108. Dept. of the Army Task 3-99-20-001 and Project 3-99-00-000.

E. Folke Bolinder. / 3668370 Archives / "June 14, 1958." / Bibliography: p. 25-27. / Army Signal Corps Contract DA36-039-sc-64637. Dept. of the Army Task 3-99-06-108 Project 3-99-00-100.

Shigebumi Saito. / "August 22, 1957. " / Bibliography: p. 50. / Army Signal Corps Contract DA36-039-sc-64637 Dept. of the Army Task 3-99-06-108 Project 3-99-00-100

H.A. Haus. / "August 18, 1955." / Bibliography: p. 62-64. / Army Signal Corps Contract DA36-039 SC-64637 Project 102B Dept. of the Army Project 3-99-10-022