41 |
The design and implementation of a microprocessor controlled adaptive filterAhmed, Kadrya Mohammed January 1986 (has links)
This thesis describes the construction and implementation of a microprocessor controlled recursive adaptive filter applied as a noise canceller. It describes the concept of the adaptive noise canceller, a method of estimating the received signal corrupted with additive interference (noise). This canceller has two inputs, the primary input containing the corrupted signal and the reference input consisting of the additive noise correlated in some unknown way to the primary noise. The reference input is filtered and subtracted from the primary input without degrading the desired components of the signal. This filtering process is adaptive and based on Widrow-Hoff Least-Mean-Square algorithm. Adaptive filters are programmable and have the capability to adjust their own parameters in situations where minimum piori knowledge is available about the inputs. For recursive filters, these parameters include feed-forward (non-recursive) as well as feedback (recursive) coefficients. A new design and implementation of the adaptive filter is suggested which uses a high speed 68000 microprocessor to accomplish the coefficients updating operation. Many practical problems arising in the hardware implementation are investigated. Simulation results illustrate the ability of the adaptive noise canceller to have an acceptable performance when the coefficients updating operation is carried out once every N sampling periods. Both simulation and hardware experimental results are in agreement.
|
42 |
Process and Analysis of Voice Signal by MATLABWu, Nan, Wang, Bofei January 2014 (has links)
Deliver message by voice is the most important, effective and common method of exchange information for mankind. Language is human specific features and human voice is commonly used tool which is also the important way to pass information to each other. The voice has large information capacity. So we can use modern method to study voice processing technology, so that people can easily transmit, store, access and apply the voice. In this thesis, we designed a collection system that can collect voice and use different filters to filter the noise. After filtering the noise, the voice will be more quality in mobile communication, radio, TV and so on. In this thesis we use Microsoft recorder to collect a voice, and then analyze its time-domain, the frequency spectrum and the characteristics of the voice signal. We use MATLAB‟s function to remove the noise which has been added to the voice, further use bilinear transformation method to design a filter which is based on Butterworth simulation and window function and then filter the voice signal which has been added noise. After that we compare the time-domain and frequency-domain of the original voice and noised voice, then playback the noised voice and de-noising voice and then compare the application of signal processing in FIR filter and IIR filter, especially in the perspectives of the signal filtering de-noising characteristics and applications. According to the comparison, we can determine which filter is the best.
|
43 |
Digital signal processing architectures for speech recognitionWells, Ian January 1995 (has links)
No description available.
|
44 |
Identification of Streptomyces Species Using Fluorescent Antibody-Membrane Filter TechniquesSingleton, Jackson David 08 1900 (has links)
It is the purpose of this investigation to modify existing methods in an attempt to provide a rapid identification of members of the genus Streptomyces.
|
45 |
Membrane fouling during domestic water recyclingLodge, Benjamin Nicholas January 2003 (has links)
The performance of a combined biological aerated filter (BAF) and an ultrafiltration (UF) system for the treatment of real and synthetic greywater, settled sewage, rainwater and borehole water has been assessed at both full-scale (at the Millennium Dome Water Recycling plant) and bench-scale. Irreversible membrane fouling was explained at bench-scale in terms of a simple but novel model whereby a proportion of the membrane area is progressively blocked, in proportion to the square root of the transmembrane pressure. This model provides a link between irreversible fouling and reversible cake filtration theory, as the predicted reduction in effective filtration area leads to increased solids loading on the unblocked area. In addition, the bulk properties (specific cake resistance and compressibility) of the filter cakes formed from biologically-treated real grey water and sewage were found to be indistinguishable. A statistical analysis of the results of longer term irreversible fouling trials at bench- scale led to numerical relationships between fouling rate and process conditions. These relationships facilitated the development of a process optimisation model, with the dual-aim of maximising output and minimising chemical consumption. At full-scale, a statistical technique was developed for calculating the relative fouling propensity of three water sources (real grey water, rainwater and borehole water) that were combined in the feed to a UP membrane. The technique was based on the relative volumes of the three sources and the mean operating trans membrane pressure. In addition, the impact of mechanical reliability on the financial viability of the full- scale plant was investigated. A Net Present Value analysis revealed that the break- even price (BEP) of the recycled water was reduced from £ 1.611m3 to £ 1.40/m 3 through increasing availability from 73.8% to 91.2%, and this can be achieved by investing in a targeted critical spares facility.
|
46 |
Malware Recognition by Properties of ExecutablesRedfern, Cory 20 December 2009 (has links)
This thesis explores what patterns, if any, exist to differentiate non-malware from malware, given only a sequence of raw bytes composing either a received file or a fixed-length initial segment of a received file. If any such patterns are found, their effectiveness as filtering criteria is investigated.
|
47 |
Validation ciel d'une commande haute performance en optique adaptative classique et multi-objet sur le démonstrateur CANARY / On-sky validation of high performance control in classical and multi-object adaptive optics on CANARY pathfinderSivo, Gaetano 10 December 2013 (has links)
L'optique adaptative (OA), qui permet de corriger en temps-réel les déformations du front d'onde induites par la turbulence atmosphérique, connaît une limitation fondamentale : l'anisoplanétisme. Pour y remédier, le concept d'OA grand champ (OAGC) a été proposé. La turbulence est mesurée dans plusieurs directions du champ de vue à l'aide d'étoiles guide naturelles et laser, et son impact corrigé sur les images par une commande basée sur une reconstruction tomographique. L'approche linéaire quadratique gaussienne (LQG) est bien adaptée à la conception de lois de commande en OAGC comme en OA classique. Elle permet d'estimer et de prédire la phase à l'aide d'un filtre de Kalman basé sur des a priori spatiaux et temporels. Les modèles d'état et commandes associées sont détaillés. On présente la première mise en oeuvre sur le ciel d'une commande LQG sur tous les modes, en OA classique et multi-objet, à l'aide du démonstrateur CANARY. Ces résultats sont obtenus avec identification du modèle de tip-tilt et filtrage des vibrations, ce qui constitue la première mise en oeuvre ciel de cette stratégie. Les a priori spatiaux de la phase en volume sont identifiés par la méthode LEARN. Des données issues du profilomètre stereoSCIDAR ont aussi été utilisées. Des comparaisons sont proposées avec une commande intégrateur en OA classique, avec un gain significatif en performances pour le LQG. Les comparaisons avec le reconstructeur statique APPLY (moindres carrés régularisés) en OA multi-objet mettent en évidence un gain du LQG dans certains cas (fort bruit en particulier). L'ensemble des résultats confirme la faisabilité et l'intérêt d'une commande LQG pour un instrument d'OA ou d'OAGC. / Adaptive Optics (AO), which enables to correct in real time wavefront deformation induced by atmospheric turbulence, faces a fundamental limitation: anisoplanatism. To counter it, the concept of Wide-Field AO (WFAO) has been proposed. Turbulence is measured in several directions of the field of view, using natural and laser guide stars, and its impact on images is mitigated by a control based on tomographic reconstruction. The Linear Quadratic Gaussian (LQG) approach is well-suited to AO control design in both WFAO and classical AO. LQG enables to estimate and predict the phase with a Kalman filter based on spatial and temporal priors. State-space models and associated controls are laid out. The first on-sky implementation of LQG control on all modes, in classical and multi-object AO, is presented on the CANARY pathfinder. These results have been obtained with identification of tip-tilt models and vibration filtering, which constitutes the first on-sky implementation of this strategy. Spatial priors on the phase in the volume are identified using the LEARN algorithm. Data from the stereoSCIDAR profilometer were also used. Comparisons are provided with integral AO control in standard AO, showing significant gain in performance with LQG. Comparisons with the static reconstructor APPLY (regularized least-squares) in multi-object AO show a gain in performance with LQG in some cases (especially in high-noise conditions). Results confirm feasibility and relevance of LQG control for AO or WFAO instruments.
|
48 |
Data Smoothing: Research 2002Strang, Gilbert 01 1900 (has links)
My research is concentrated on applications of linear algebra in engineering, including wavelet analysis and structured matrices. This paper will appear in the book Mathematical Systems Theory (J. Rosenthal and D. Gilliam, editors) IMA Volumes in Mathematics, Springer 2002. / Singapore-MIT Alliance (SMA)
|
49 |
Acid placement and coverage in the acid jetting processMikhailov, Miroslav I. 15 May 2009 (has links)
Many open-hole acid treatments are being conducted by pumping acid through jetting ports placed at the end of coiled tubing or drill pipe. The filter-cake on the bore-hole is broken by the jet; the acid-soluble material is dissolved, creating wormholes in the formation. This combination of two acting factors creates more stimulation beyond the jetting action area. Existing papers have mentioned the advantages of using jetting both for damage removal and as the preliminary stage before further acidizing. Many papers discuss theory and practical implementation of wormholing during acid jobs and the resulting injectivity enhancement, too. However, there is no complete research regarding jetting efficiency with regards to permeability restoration due to filter-cake disruption, and therefore, no data exists for efficient filter-cake removal by acid jetting just prior to wormholing. My project objective is to conduct experiments of acid jetting, defining the parameters that aid to restore injectivity. Based on the parameters obtained from the experiments, I developed a set of recommendations for acid jetting design and optimization.
|
50 |
Modeling of a Tunable Film Bulk Acoustic Resonator and Bandpass Filter Design by using Ferroelectric FilmJavaid, Usman January 2011 (has links)
Filters having smallest size, high power handling capability, high Q factor, operating frequency up to several gigahertz’s (GHz) and low cost are the demand of the market to use in front end wireless/radio communication systems. In this regard several filter technologies have been introduced and utilized commercially. The increasing demand of such type of filters has opened a new challenge for filter designers. The purpose of this thesis is to design of a Tunable Bandpass Filter based on Barium Strontium Titanate (BSTO) Ferroelectric Film. A single Film bulk acoustic resonator (FBAR) is measured. MASON and Butterworth Van-Dyke (BVD) model are studied and implemented to reproduce the measurements. Simulations are performed by using the Advance Design System (ADS) by Agilent technologies. Simulations and measured data are used to exactly extract the physical and electrical parameters of a single FBAR. FBAR filter topologies are being studied and implemented. Ladder filter topology is selected to design the bandpass filter. The extracted physical and electrical parameters are used to investigate the performance of the filter. The area and the top electrode thickness of the series and shunt resonators are optimized to achieve the bandpass response with maximum out of band rejection, minimum insertion loss and sharper roll off near the pass band. A 3rd order T-type bandpass filter for 5GHz applications is designed. The insertion loss of -2.925 dB is achieved. The filter exhibits the 3dB bandwidth of 176 MHz and out of band rejection of -10 dB. DC bias of 0-25 V is used to analyze the tuning behavior of the filter. The electromagnetic co-simulation is also done in momentum to analyze the parasitic effects between the resonators. The results show the good agreement between the schematic and momentum simulation. Layout and masks are also designed on a 10*10 mm wafer that will be used later to fabricate the filter and further investigations.
|
Page generated in 0.0328 seconds