Дисертації з теми "Frequency domain approach"
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Mui, Chi Seong. "Frequency domain approach to time series analysis." Thesis, University of Macau, 2000. http://umaclib3.umac.mo/record=b1446676.
Повний текст джерелаHo, C. "Nonlinear vibration control : a frequency domain approach." Thesis, University of Sheffield, 2014. http://etheses.whiterose.ac.uk/5157/.
Повний текст джерелаWarburton, Niels Jamie. "Frequency domain approach to self-force calculations." Thesis, University of Southampton, 2012. https://eprints.soton.ac.uk/167481/.
Повний текст джерелаChao, Chi-Shun. "A frequency domain based approach to on-line system identification." Thesis, Monterey, California. Naval Postgraduate School, 1991. http://hdl.handle.net/10945/28237.
Повний текст джерелаVaudrey, Michael A. "A novel approach to multiple reference frequency domain adaptive control." Thesis, This resource online, 1996. http://scholar.lib.vt.edu/theses/available/etd-08292008-063731/.
Повний текст джерелаSchamel, Andreas. "A frequency domain approach to the analysis and optimization of valve spring dynamics." Thesis, Loughborough University, 1993. https://dspace.lboro.ac.uk/2134/14724.
Повний текст джерелаJun, Jonathan Ho. "An abductive approach to Design Structure Matrix (DSM) partitioning using frequency domain scoring." Thesis, Massachusetts Institute of Technology, 2018. http://hdl.handle.net/1721.1/118547.
Повний текст джерелаCataloged from PDF version of thesis.
Includes bibliographical references (pages 65-66).
A key benefit of the DSM representation is that it gives a visual interpretation of relationships between its elements. The array format allows us to sort the elements using clustering algorithms which try to group the relationships into modules which are as independent as possible. There are a number of clustering algorithms available which may each end up sorting the DSMs differently using different objectives, for example, activities in a time-based DSM can be sequenced to reduce iterations or to improve concurrency. However, most of these algorithms take a deductive approach which results in only one 'optimal' output. If an abductive approach is used instead, multiple solutions can be generated for the user to evaluate, some which may provide insight on useful configurations that he or she may have overlooked. In electrical engineering, we often make use of transforms to convert time domain signals into frequency domain signals in order to glean additional information which may not have been initially apparent. In this respect, using a frequency domain transform on a DSM matrix gives us additional insights into the relationships represented. An example of one such insight would be into the sorted-ness of a DSM to which module cuts can be defined. By applying a frequency transform to a pixel representation of the DSM and examining the transform coefficients, we gain an understanding of what image patterns exist in the DSM. Rules pertaining to these coefficients could then be defined which would classify a DSM as well sorted (with the dependencies being grouped up) or being unsorted (with the dependencies being scattered). This thesis demonstrates the above technique to rank each permutation of an 8x8 matrix on their conformance to certain rules or behaviors in order to filter out useful configurations in an abductive approach. When comparing the highest-ranking hypotheses against the optimal result from other clustering and sequencing algorithms, this algorithm performed on par with them to reduce external dependencies and iterations respectively. The frequency based scoring was also shown to be a useful metric when determining the optimal module cut of a system.
by Jonathan Ho Jun.
S.M. in Engineering and Management
MacKay, Cameron. "An optimisation approach to the frequency-domain inverse problem for a nonuniform transmission line." Thesis, University of Strathclyde, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.410242.
Повний текст джерелаThein, Christoph Oliver [Verfasser]. "A frequency domain approach to synchronization of filterbank multicarrier systems in practice / Christoph Oliver Thein." Hannover : Technische Informationsbibliothek und Universitätsbibliothek Hannover (TIB), 2015. http://d-nb.info/106892425X/34.
Повний текст джерелаFLADUNG, JR WILLIAM A. "A GENERALIZED RESIDUALS MODEL FOR THE UNIFIED MATRIX POLYNOMIAL APPROACH TO FREQUENCY DOMAIN MODAL PARAMETER ESTIMATION." University of Cincinnati / OhioLINK, 2001. http://rave.ohiolink.edu/etdc/view?acc_num=ucin990800667.
Повний текст джерелаSelander, Keith N. "A function space approach to the generalized nonlinear model with applications to frequency domain spectral estimation." Diss., This resource online, 1992. http://scholar.lib.vt.edu/theses/available/etd-06062008-172034/.
Повний текст джерелаTatossian, Charles A. "Aerodynamic shape optimization via control theory of helicopter rotor blades using a non-linear frequency domain approach." Thesis, McGill University, 2008. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=112586.
Повний текст джерелаWilzeck, Andreas. "A software defined radio approach for high data rate multi-antenna wireless communications with frequency domain processing." Aachen Shaker, 2009. http://d-nb.info/997951338/04.
Повний текст джерелаSALAM, ABDUL. "Model-based and data-based frequency domain design of fixed structure robust controller: a polynomial optimization approach." Doctoral thesis, Politecnico di Torino, 2022. https://hdl.handle.net/11583/2972836.
Повний текст джерелаFERNANDEZ, BARRERO DIEGO. "Dynamic Soil-Structure Interactionof Soil-Steel Composite Bridges : A Frequency Domain Approach Using PML Elements and Model Updating." Thesis, KTH, Bro- och stålbyggnad, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-256033.
Повний текст джерелаLjung, Jonathan. "Parametric Studies of Soil-Steel Composite Bridges for Dynamic Loads, a Frequency Domain Approach using 3D Finite Element Modelling." Thesis, KTH, Bro- och stålbyggnad, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-254343.
Повний текст джерелаLui, Man Leung. "A new 2-dimensional full-wave frequency-domain approach for direct dispersion analysis of arbitrarily shaped wave-guiding structures." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0020/MQ48279.pdf.
Повний текст джерелаWilzeck, Andreas [Verfasser]. "A Software Defined Radio Approach for High Data-Rate Multi-Antenna Wireless Communications with Frequency Domain Processing / Andreas Wilzeck." Aachen : Shaker, 2009. http://d-nb.info/1159836337/34.
Повний текст джерелаDizemen, Ilke Evrim. "Assessment Of An Iterative Approach For Solution Of Frequency Domain Linearized Euler Equations For Noise Propagation Through Turbofan Jet Flows." Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/12609095/index.pdf.
Повний текст джерелаSmith, Austin Gregory. "Characterization and Quantification of Early Stages for Organic Coatings Applied on AA2024/AA7075 by Correlating Frequency Domain Approach in Real Time." University of Akron / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=akron1399125698.
Повний текст джерелаBaby, Arun Paul. "Comparison of Modal Parameter Estimation using State Space Methods (N4SID) and the Unified Matrix Polynomial Approach." University of Cincinnati / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1613731964598438.
Повний текст джерелаBzikha, Ihssane. "Comparison and development of advanced wiring fault detection methods on coaxial cables." Thesis, Limoges, 2019. http://www.theses.fr/2019LIMO0119.
Повний текст джерелаIn this thesis, we present new approaches of soft fault detection and location in simple andcomplex wire networks. The idea is to find a new approach to overcome the difficulties withstandard reflectometry techniques. We prove that before applying post-treatment methods,denoising techniques should be applied, such as empirical mode decomposition (EMD), localmean decomposition (LMD), or the discrete wavelet transform (DWT). These three methodsdecompose a signal into multiple levels to threshold them before signal reconstruction.Testing several applications shows that EMD is the most efficient method, although it hassome limitations as side effects. After the denoising step, the wiring faults can be detected.Time–frequency analysis is employed at this step. This approach, based on the FourierTransform, is able to detect wiring faults only if the noise level is low. To overcome thisdifficulty, the Bayesian approach is beneficial when system complexity increases. Its responseis based on estimation of prior parameters and prior distributions. In this work, the Bayesianapproach is applied via a formal mathematical study followed by simulation results validatingthe proposed approach, with analysis of the parameters that affect the method’s performance.In the domain of soft fault location, we derive a chaos time domain reflectometry approachbased on chaotic signal properties. Our simulation and experimental results prove that thismethod can synthesize signals and localize the soft fault position without the need forsupplemental methods
Trad, Farah. "Stability of some hyperbolic systems with different types of controls under weak geometric conditions." Electronic Thesis or Diss., Valenciennes, Université Polytechnique Hauts-de-France, 2024. http://www.theses.fr/2024UPHF0015.
Повний текст джерелаThe purpose of this thesis is to investigate the stabilization of certain second order evolution equations. First, we focus on studying the stabilization of locally weakly coupled second order evolution equations of hyperbolic type, characterized by direct damping in only one of the two equations. As such systems are not exponentially stable , we are interested in determining polynomial energy decay rates. Our main contributions concern abstract strong and polynomial stability properties, which are derived from the stability properties of two auxiliary problems: the sole damped equation and the equation with a damping related to the coupling operator. The main novelty is thatthe polynomial energy decay rates are obtained in several important situations previously unaddressed, including the case where the coupling operator is neither partially coercive nor necessarily bounded. The main tools used in our study are the frequency domain approach combined with new multipliers technique based on the solutions of the resolvent equations of the aforementioned auxiliary problems. The abstract framework developed is then illustrated by several concrete examples not treated before. Next, the stabilization of a two-dimensional Kirchhoff plate equation with generalized acoustic boundary conditions is examined. Employing a spectrum approach combined with a general criteria of Arendt-Batty, we first establish the strong stability of our model. We then prove that the system doesn't decay exponentially. However, provided that the coefficients of the acoustic boundary conditions satisfy certain assumptions we prove that the energy satisfies varying polynomial energy decay rates depending on the behavior of our auxiliary system. We also investigate the decay rate on domains satisfying multiplier boundary conditions. Further, we present some appropriate examples and show that our assumptions have been set correctly. Finally, we consider a wave wave transmission problem with generalized acoustic boundary conditions in one dimensional space, where we investigate the stability theoretically and numerically. In the theoretical part we prove that our system is strongly stable. We then present diverse polynomial energy decay rates provided that the coefficients of the acoustic boundary conditions satisfy some assumptions. we give relevant examples to show that our assumptions are correct. In the numerical part, we study a numerical approximation of our system using finite volume discretization in a spatial variable and finite difference scheme in time
Giuliani, Corrado. "Automatic analysis of electrocardiographic repolarization: innovative approaches in the time and frequency domains." Doctoral thesis, Università Politecnica delle Marche, 2015. http://hdl.handle.net/11566/242935.
Повний текст джерелаSudden cardiac death (SCD) is one of the leading causes of death in developed countries. Consequently, several noninvasive predictors of SCD based on the T-wave, that is the cardiac repolarization on electrocardiogram (ECG) tracings, have been proposed in the literature, such as the QT-interval and the T-wave alternans. However, none of these indexes has proven sufficient sensitivity and specificity to justify preventive treatments. Abnormalities in the repolarization morphology are reflected, in the frequency domain, in a variation of the T-wave frequency content. Thus, aims of the present thesis are: (i) to propose innovative frequency-based repolarization index (Toff) and (ii) to improve QT-interval reliability introducing a new procedure to help identify T-wave offsets (Toff). To aim (i), 4 new indexes are proposed, termed AUNE2-5, AUNE10-35, TCE10 and f99, and their ability to discriminate clinical to pathological condition or to assess cardiovascular risk is evaluated. As a result, the f99 is the most promising frequency-based repolarization index among all proposed, being able to assess cardiovascular risk, even though each of these indexes is able to discriminate clinical to pathological condition. To aim (ii), the dominant T-wave (DTW), which is a global repolarization waveform, is used to improve QT-interval reliability by identifying Toff on DTWs computed over all the clinical available 15 ECG leads and then over smaller, yet linear independent, leads' groups, to test if data redundancy could bias the analysis. As a result, Toff identification by two automatic methods is equivalent when performed on DTWs computed over 15 leads and results are not affected by data redundancy, being statistically comparable and strongly correlated when Toffs are identified on DTWs computed over 8 or more leads. In conclusion, the proposed innovative f99 index and the use of DTW to improve QT-interval reliability represent a step further in the ECG repolarization analysis.
Lee, Kyungmi. "Effective Approaches to Extract Features and Classify Echoes in Long Ultrasound Signals from Metal shafts." Thesis, Griffith University, 2007. http://hdl.handle.net/10072/366794.
Повний текст джерелаThesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Information and Communication Technology
Full Text
El, Hellani Doha. "Approche LMI pour l'analyse et la synthèse de filtres H∞ dans un domaine fréquentiel fini." Electronic Thesis or Diss., Amiens, 2018. http://www.theses.fr/2018AMIE0021.
Повний текст джерелаThis work is concerned with the H∞ filtering problem in a finite frequency domain for different types of dynamic systems, such that uncertain systems, nonlinear systems via TS fuzzy model, time delay systems and systems with communication constraints. The main contribution is the development of new H∞ filter analysis and design approaches which reduce the conservatism of results found in the literature. The filter stability and design problems, for different classes of dynamic systems, are formulated as optimization problems with Linear Matrix Inequality (LMI). Simulation examples are presented to demonstrate the effectiveness and the less conservatism of the proposed approaches in comparison with other solutions that appear in the literature
Lamara, Abderrahim. "Approche CRONE multivariable : développement et application à la régulation de bancs d'essais moteur haute dynamique." Thesis, Bordeaux, 2015. http://www.theses.fr/2015BORD0069/document.
Повний текст джерелаThe work presented in this Thesis is part of the CRONE (robust control with fractional integration order) multivariable methodology development. It deals with the simplification of the robust multivariable control system implementation with application to the control of high dynamic engine test-benches, including those developed by the D2T company. The first chapter introduces different kind of test-benches and gives a general idea about how those systems work while explaining their problems. While the first part of chapter II presents a simple method for test-benches modeling which then allows their simulation, the second part is dedicated to their frequency-domain system identification. The defined identification procedure is applied to a test-bench equipped with a Diesel engine. The third chapter presents the CRONE multivariable methodology and different developments to simplify its use. Reflecting these developments, the developed CRONE multivariable toolbox is used to design a control system for a test-bench consists of two asynchronous motors. The fourth chapter is dedicated to validate the presented work by applying these developments to a high dynamic test-bench with a spark ignition engine. This chapter presents the various software tools developed to simplify the implementation to D2T products of the CRONE full MIMO methodology
Zarudniev, Mykhailo. "Synthèse de fréquence par couplage d'oscillateurs spintroniques." Phd thesis, Ecole Centrale de Lyon, 2013. http://tel.archives-ouvertes.fr/tel-00804561.
Повний текст джерелаYang, Li Tung, and 李東陽. "Nonlinear System Identification: Time-Frequency Domain Approach." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/93307553240433948283.
Повний текст джерела國立臺灣大學
土木工程學研究所
91
This dissertation presents the development of structural identification procedures for a nonlinear SDOF system. It consists of three parts: i) Test of the system nonlinearity using input/output data or only using output data, ii) Reconstruct the nonlinear system restoring force mathmatical model, iii) Reconstruct system NARX model. The tests of nonlinearity conclude HTD test and bispectrum test. The restoring force mathematical model is established by chebyshev polynomials. And the system NARX model is solved by orthogonal least square method. Finally, a numerical simulation of inelastic SDOF system with Bouc-Wen model and an experimental study of 3-Story RCS frame were used to test the applicability of the proposed methods.
LIAO, WEI-LIANG, and 廖威量. "Flutter analysis of an oscillating airfoil by frequency domain approach." Thesis, 1989. http://ndltd.ncl.edu.tw/handle/71646600072201712337.
Повний текст джерелаSha, Shaoshu. "A frequency domain approach for time-reversal of microwave impulses." 2009. http://hdl.handle.net/10106/1787.
Повний текст джерелаChen, Chi-Hsiao, and 陳基孝. "Frequency Domain Approach for Multiple Narrowband Interference Cancellation in GPS Receivers." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/80206365751356834513.
Повний текст джерела國立臺灣大學
電子工程學研究所
101
Nowadays, GPS (Global Positioning System) has been widely integrated into consumer electronics products. The harmonic frequencies caused by other components may interfere with the GPS receivers. Therefore, GPS receivers need to implement an interference excision mechanism to deal with the issue. In this thesis, we propose using the consecutive mean excision (CME) algorithm, which is a frequency-domain-based digital signal processing (DSP) approach, to implement an anti-jamming filter. The CME algorithm leverages the fact that the magnitude spectrum of the un-jammed GPS signal should have a Rayleigh distribution to adaptively adjust an excision threshold. By excising all the frequency bins whose magnitudes are above the threshold, the resulting magnitude spectrum ideally becomes Rayleigh distribution again. Therefore, the narrow band jamming signals can be eliminated. Moreover, the impaction of the proposed anti-jamming filter on the acquisition and tracking loops in the GPS receiver is analyzed. Finally, we compare the approach in this thesis with one related previous work. Our method can handle more than two times the number of interference and at most eight jamming signals with jamming-to-signal ratio (JSR) of 25 dB. In this case, the anti-jamming filter does not affect the acquisition of C/A code phase and the resulting detection probability is over 90%; the resulting tracking errors are 10-3 chips, 0.5 Hz, and 0.20, with respect to the code phase, carrier frequency, and carrier phase.
Huang, Kuen-Yu, and 黃堃宇. "A Time Domain Approach to High-Frequency Circuit Simulation of Semiconductor Devices." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/16133979209925385508.
Повний текст джерела國立交通大學
電子工程系所
94
In order to solve the radio-frequency (RF) steady-state, that is ,high-frequency periodic circuit problem, such as intermodulation distortion, we develop a new numerical solution technique in this dissertation to simulate circuits in time-domain. Traditional transient analysis in SPICE-like time-domain solver is not suitable for RF steady-state solution. The tough criteria for solving steady-state problem in time- domain drive us to build our own time-domain circuit solver. This solver should be stable, efficient, and able to handle strongly nonlinear circuits, for instance, the large-signal models for semiconductor devices. Combining the waveform relaxation (WR) method, monotone iterative (MI) method, and Runge-Kutta (RK) method, we succeeded in solving the circuit ordinary differential equations (ODEs) in time domain that satisfies the criteria of the RF steady-state analysis. The convergence of our developed algorithms has been proved and demonstrated in this dissertation. We also perform subsequent analysis, such as the discrete Fourier transform (DFT), to extract the frequency-domain information from simulated time-domain data. In this dissertation, we use our numerical solution techniques to simulate the characteristics of heterojunction bipolar transistors (HBTs) with the Gummel-Poon (GP) model. The results of DC circuit calculation, time-domain simulation, frequency-domain analysis and intermodulation distortion characterization are presented. Furthermore, we compare the results of various simulators (our solver, HSPICE and ADS) with measured data to show the accuracy and efficiency of the developed method. For HBTs under high bias and high power operation, the thermal effects dominate the behavior of the device. Therefore, we include the electrical-thermal interactive equations in our numerical solution technique to further improve the reality of the simulation. The difference between the simulations with and without thermal effects is well discussed in the context of this dissertation. In additional, we describe the thermal coupling effects of an multi-finger HBT and its influence on DC, RF power and intermodulation distortion characteristics. In the appendixes, the EPFL-EKV compact model of the metal-oxide semiconductor field-effect transistors (MOSFETs) is discussed and the related circuits are simulated by the proposed method and HSPICE. The convergence properties of the utilized algorithms are presented in these appendixes. According to the discussion in this dissertation, the developed approach is not only an alternative computational technique for the time-domain solution of nonlinear circuit ODEs but also can be generalized for high-frequency circuits simulation including more and variant kind of semiconductor devices.
Chevallier, Arnaud Michel. "A probabilisitc approach to the frequency domain analysis of drill-string lateral vibrations." Thesis, 1998. http://hdl.handle.net/1911/17161.
Повний текст джерелаMoghadam, Amin. "A signal-processing-based approach for damage detection of steel structures." Thesis, 2019. http://hdl.handle.net/2097/39465.
Повний текст джерелаDepartment of Civil Engineering
Hani G. Melhem
This study reports the results of an analytical, experimental and a numerical study (proof of concept study) on a proposed method for extracting the pseudo-free-vibration response of a structure using ambient vibration, usually of a random nature, as a source of excitation to detect any change in the dynamic properties of a structure that may be caused by damage. The structural response contains not only a random component but also a component reflecting the dynamic properties of the structure, comparable to the free vibration for a given initial condition. Structural response to the arbitrary excitation is recorded by one or several accelerometers with a desired data-collection frequency and resolution. The free-vibration response of the structure is then extracted from this data by removing the random component of the response by the method proposed in this study. The features of the free-vibration response of the structure extracted by a suitable method, namely Fast Fourier Transform (FFT) in this study, can be used for change detection. Possible change of the pattern of these features is dominantly linked to the change in dynamic properties of the system, caused by possible damage. To show the applicability of the concept, besides an analytical verification using Newmark’s linear acceleration method, two steel portal frames with different flexural stiffness were made in the steel workshop of the structural laboratory for an experimental study. These structures were also numerically modeled using a finite element software. A wireless accelerometer with a sampling frequency rate of 2046 Hz was affixed on the top of the physical structure, at the same location where the acceleration was recorded for the corresponding numerical model. The physical structure was excited manually by an arbitrary hit and the response of the structure to this excitation, in terms of the acceleration on the top of the structure, was recorded. The pseudo-free-vibration response was extracted and transferred into frequency domain using FFT. The frequency with the largest magnitude which is the fundamental frequency of the structure was traced. This was repeated for several independent excitations and the fundamental frequencies were observed to be the same, showing that the process can correctly identify the natural frequencies of the structure. Similarly, the numerical model was excited and for several base excitation cases, the fundamental frequencies were found to be the same. Considering the acceptable accuracy of the results from the two numerical models in simulating the response of their corresponding physical models, additional numerical models were analyzed to show the consistency and applicability of the proposed method for a range of flexural stiffness and damping ratio. The results confirm that the proposed method can precisely extract the pseudo-free-vibration response of the structures and detect the structural frequencies regardless of the excitation. The fundamental frequency is tied to the stiffness and a larger stiffness leads to a higher frequency, as expected, regardless of the simulated ambient excitation.
Wu, Chang-Yen, and 吳昌晏. "Applying Causality Frequency-Domain Approach to Test Housing Bubble-The Case of Japan and America." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/26850939197044872734.
Повний текст джерела逢甲大學
財務金融學系碩士班
101
This paper uses OECD and AMECO annual databases to investigate frequency domain causality between personal disposable income and house price index from 1970 to 2011 to determine whether there is housing bubble in Japan and USA. We find that the personal disposable income in long-term and short-term has no Granger causality with house price index in USA, but house price index has Granger causality with personal disposable income in USA. After adding stock price index as control variable, we find that both personal disposable income to house price and house price to personal income have no long-term relationship, After adding interest rate as control variable, we find that personal disposable income to house price index has middle-term Granger causality , but house price to personal disposable income has no Granger causality Before adding stock or interest rate as control variable, Japanese personal disposable income to house price has middle and short-term Granger causality and house price index to personal disposable income exists Granger causality. After adding stock price index as control variable, we find that personal disposable income to house price index has more power of Granger causality in short-term, but house price to personal disposable income has no Granger causality, After adding interest rate as control variable, both personal disposable income to house price and house price to personal income have no long-term relationship.
Wang, Chih-liang, and 王志良. "A Frequency-Domain Approach to the Design of 2-D Quadratic Filters and its Application to Image Processing." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/75167769426155470073.
Повний текст джерела國立海洋大學
電機工程學系
85
Two-dimensional(2-D) quadratic filters have been found very effective in image processing problems such as edge preserving smoothing, edge extraction, texturediscrimination, prediction of image sequences and interpolatrion of image sequences.The relation between the input and output od 1 2-D quadratic filter can be describedby a 2-D second-order Volterra series. The advantage od a quadratic filter overa traditional linear filter is derived from its more elaborate modeling capabilityin describing nonlinear effects of engineering applications. However, there is a lackof guidelines on finding an appropriate 2-D quadratic filter for a certain task. Therefore, how to design 2-D quadrat, efficiently is a bottleneck to be broken through. A solution, which was suggested by previous researchers, to this problem is to use an optimization technique. More explicity, the optimum 2-Dquadratic filter is obtained by minimizing an objective function(for example, themean square error) subject to the required I/O relation. As recorded in the literatures, conventional methods, including the steepestdescent method, the Powell's direction method, and the simulated annealing, havebeen developed. All of these methods design 2-D quadratic filters in the space-domainand obtain acceptable results. However, sometimes these methods may not lead to satisfactory results because they may consume a lot of time just to reach a localoptimum---the repayment is far behind the investment. In this thesis, a novel design methodlogy is presented. By working in the frequency-domain,the proposed method is shown to be able to determine the optimum(in the sense of minimummean square error) filter coefficients of the 2-D quadratic filter. We show that, in the frequency-domain, the constrained optimization task in the conventional approach can beconverted to an unconventional problem with a quadratic objective function. Suchan objective function guarantees that the global optimum, instead of a local optimum, can be easily obtained. The feasibility of the novel technique will be verified by an applicationexample.
Chen, Ying Hao, and 陳英儫. "The link between expenditure for Police Service and Number of fraud or Number of theft--A frequency-domain approach." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/92132344544741569262.
Повний текст джерелаYing, Chen-Ling, and 應誠霖. "Design of Quantitative Robust Control Systems Using Frequency Domain Approaches." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/98601375305746057819.
Повний текст джерела元智大學
電機工程學系
90
In this dissertation, the equivalent disturbance rejection (EDR) design method is introduced to achieve quantitative robust control performance. Using this design method, the maximum variations of the uncertain plant can be transferred to an equivalent disturbance, and the maximum variations of the system tolerance can be transferred to a specified output response. The quantitative specification is then formulated in the inverse Nichols chart by calculating the values of bound functions at some specified frequencies using the sensitivity concept. Previous EDR design method is extended to handle stable and unstable systems plus both minimum and non-minimum phase multivariable systems in this dissertation. Finally, by loop shaping in the inverse Nichols chart, a robust controller can be designed to achieve quantitative robust performance. This dissertation also presents a design algorithm of involving robust decoupled control of uncertain multivariable feedback systems. For two-degree-of-freedom (2-DOF) system, quantitative feedback theory (QFT) is applied for feedback compensator design to achieve quantitative robustness. A decoupled model matching approach is employed for prefilter design to achieve input-output decoupling performance. On the other hand, the synthesis methodology of multivariable quantitative robust linear quadratic optimal control system is developed. Wiener-Hopf linear quadratic optimal control is introduced and is then incorporated with quantitative feedback theory robust control design technique to achieve the quantitative robust optimal control. Finally, an integrated control and diagnostic design method is proposed which uses the four-degree-of-freedom scheme. The robust controller presents a two-degree-of-freedom structure including the feedback controller and the prefilter. For failure diagnosis, the diagnostic filters are chosen to perform the fault detection. The adjoint technique is applied for threshold value determination to meet the diagnostic performance.
Ghosh, Rupak. "Effect of top tensioned risers (TTR) on the spar responses: Time domain and frequency domain approaches." Thesis, 2005. http://hdl.handle.net/1911/18766.
Повний текст джерелаWood, Sean. "Non-negative matrix decomposition approaches to frequency domain analysis of music audio signals." Thèse, 2009. http://hdl.handle.net/1866/3769.
Повний текст джерелаWe study the application of unsupervised matrix decomposition algorithms such as Non-negative Matrix Factorization (NMF) to frequency domain representations of music audio signals. These algorithms, driven by a given reconstruction error function, learn a set of basis functions and a set of corresponding coefficients that approximate the input signal. We compare the use of three reconstruction error functions when NMF is applied to monophonic and harmonized musical scales: least squares, Kullback-Leibler divergence, and a recently introduced “phase-aware” divergence measure. Novel supervised methods for interpreting the resulting decompositions are presented and compared to previously used methods that rely on domain knowledge. Finally, the ability of the learned basis functions to generalize across musical parameter values including note amplitude, note duration and instrument type, are analyzed. To do so, we introduce two basis function labeling algorithms that outperform the previous labeling approach in the majority of our tests, instrument type with monophonic audio being the only notable exception.