To see the other types of publications on this topic, follow the link: Discrete Fourier transforms (DFTs).

Dissertations / Theses on the topic 'Discrete Fourier transforms (DFTs)'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 32 dissertations / theses for your research on the topic 'Discrete Fourier transforms (DFTs).'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.

1

Heiskanen, Andreas, and Erik Johansson. "Analysing Memory Performance when computing DFTs using FFTW." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-230225.

Full text
Abstract:
Discrete Fourier Transforms (DFTs) are used in a wide variety of dif-ferent scientific areas. In addition, there is an ever increasing demand on fast and effective ways of computing DFT problems with large data sets. The FFTW library is one of the most common used libraries when computing DFTs. It adapts to the system architecture and predicts the most effective way of solving the input problem. Previous studies have proved the FFTW library to be superior to other DFT solving libraries. However, not many have specifically examined the cache memory performance, which is a key factor for overall
APA, Harvard, Vancouver, ISO, and other styles
2

Akhtar, Mahmood Electrical Engineering &amp Telecommunications Faculty of Engineering UNSW. "Genomic sequence processing: gene finding in eukaryotes." Publisher:University of New South Wales. Electrical Engineering & Telecommunications, 2008. http://handle.unsw.edu.au/1959.4/40912.

Full text
Abstract:
Of the many existing eukaryotic gene finding software programs, none are able to guarantee accurate identification of genomic protein coding regions and other biological signals central to pathway from DNA to the protein. Eukaryotic gene finding is difficult mainly due to noncontiguous and non-continuous nature of genes. Existing approaches are heavily dependent on the compositional statistics of the sequences they learn from and are not equally suitable for all types of sequences. This thesis firstly develops efficient digital signal processing-based methods for the identification of genomic
APA, Harvard, Vancouver, ISO, and other styles
3

Khan, Aman Ullah. "Parallel computation of fast Fourier transforms." Thesis, Cardiff University, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.340239.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Al-Harbi, Hamad F. "Crystal plasticity finite element simulations using discrete Fourier transforms." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/51788.

Full text
Abstract:
Crystallographic texture and its evolution are known to be major sources of anisotropy in polycrystalline metals. Highly simplified phenomenological models cannot usually provide reliable predictions of the materials anisotropy under complex deformation paths, and lack the fidelity needed to optimize the microstructure and mechanical properties during the production process. On the other hand, physics-based models such as crystal plasticity theories have demonstrated remarkable success in predicting the anisotropic mechanical response in polycrystalline metals and the evolution of underlying t
APA, Harvard, Vancouver, ISO, and other styles
5

Arof, H. "Texture classification and segmentation using one dimensional discrete Fourier transforms." Thesis, Swansea University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.635797.

Full text
Abstract:
This thesis introduces a texture descriptor that is invariant to rotation. The new texture descriptor utilizes the property of the magnitudes of Fourier transform coefficients that do not change with spatial shift of input elements. Since rotating an image by an arbitrary angle does not change pixel intensities in an image but shifts them in circular motion, the notion of producing texture features invariant to rotation using 1-D Fourier transform coefficients can be realized if the relationship between circular motion and spatial shift can be established. By analyzing individual circular neig
APA, Harvard, Vancouver, ISO, and other styles
6

Barrera, David. "Quenched Asymptotics for the Discrete Fourier Transforms of a Stationary Process." University of Cincinnati / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1460652609.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Sayyah, Jahromi Mohammad Reza Information Technology &amp Electrical Engineering Australian Defence Force Academy UNSW. "Efficient broadband antenna array processing using the discrete fourier form transform." Awarded by:University of New South Wales - Australian Defence Force Academy. School of Information Technology and Electrical Engineering, 2005. http://handle.unsw.edu.au/1959.4/38690.

Full text
Abstract:
Processing of broadband signals induced on an antenna array using a tapped delay line filter and a set of steering delays has two problems. Firstly one needs to manipulate large matrices to estimate the filter coefficients. Secondly the use of steering delays is not only cumbersome but implementation errors cause loss of system performance. This thesis looks at both of these problems and presents elegant solutions by developing and studying a design method referred to as the DFT method, which does not require steering delays and is computationally less demanding compared to existing methods.
APA, Harvard, Vancouver, ISO, and other styles
8

Ganesh, Murthy C. N. S. "A Study On Bandpassed Speech From The Point Of Intelligibility." Thesis, Indian Institute of Science, 1989. http://hdl.handle.net/2005/93.

Full text
Abstract:
Speech has been the subject of interest for a very long time. Even with so much advancement in the processing techniques and in the understanding of the source of speech, it is, even today, rather difficult to generate speech in the laboratory in all its aspects. A simple aspect like how the speech can retain its intelligibility even if it is distorted or band passed is not really understood. This thesis deals with one small feature of speech viz., the intelligibility of speech is retained even when it is bandpassed with a minimum bandwidth of around 1 KHz located any where on the speech spect
APA, Harvard, Vancouver, ISO, and other styles
9

Bleiler, Sarah K. "Orthogonal filters and the implications of wrapping on discrete wavelet transforms." [Tampa, Fla] : University of South Florida, 2008. http://purl.fcla.edu/usf/dc/et/SFE0002676.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Lo, King Chuen. "Theory and realization of novel algorithms for random sampling in digital signal processing." Thesis, Durham University, 1996. http://etheses.dur.ac.uk/5239/.

Full text
Abstract:
Random sampling is a technique which overcomes the alias problem in regular sampling. The randomization, however, destroys the symmetry property of the transform kernel of the discrete Fourier transform. Hence, when transforming a randomly sampled sequence to its frequency spectrum, the Fast Fourier transform cannot be applied and the computational complexity is N(^2). The objectives of this research project are (1) To devise sampling methods for random sampling such that computation may be reduced while the anti-alias property of random sampling is maintained : Two methods of inserting limite
APA, Harvard, Vancouver, ISO, and other styles
11

Hickman, Jonathan Edward. "Topics in affine and discrete harmonic analysis." Thesis, University of Edinburgh, 2015. http://hdl.handle.net/1842/10559.

Full text
Abstract:
In this thesis a number of problems in harmonic analysis of a geometric flavour are discussed and, in particular, the Lebesgue space mapping properties of certain averaging and Fourier restriction operators are studied. The first three chapters focus on the perspective afforded by affine-geometrical considerations whilst the remaining chapter considers some discrete variants of these problems. In Chapter 1 there is an overview of the basic affine theory of the aforementioned operators and, in particular, the affine arc-length and surface measures are introduced. Chapter 2 presents work of the
APA, Harvard, Vancouver, ISO, and other styles
12

Miar, Yasin. "Improved Wideband Spectrum Sensing Methods for Cognitive Radio." Thèse, Université d'Ottawa / University of Ottawa, 2012. http://hdl.handle.net/10393/23333.

Full text
Abstract:
Abstract Cognitive Radio (CR) improves the efficiency of spectrum utilization by allowing non- licensed users to utilize bands when not occupied by licensed users. In this thesis, we address several challenges currently limiting the wide use of cognitive radios. These challenges include identification of unoccupied bands, energy consumption and other technical challenges. Improved accuracy edge detection techniques are developed for CR to mitigate both noise and estimation error variance effects. Next, a reduced complexity Simplified DFT (SDFT) is proposed for use in CR. Then, a sub-Nyquist ra
APA, Harvard, Vancouver, ISO, and other styles
13

baktir, selcuk. "Frequency Domain Finite Field Arithmetic for Elliptic Curve Cryptography." Digital WPI, 2008. https://digitalcommons.wpi.edu/etd-dissertations/272.

Full text
Abstract:
Efficient implementation of the number theoretic transform(NTT), also known as the discrete Fourier transform(DFT) over a finite field, has been studied actively for decades and found many applications in digital signal processing. In 1971 Schonhage and Strassen proposed an NTT based asymptotically fast multiplication method with the asymptotic complexity O(m log m log log m) for multiplication of $m$-bit integers or (m-1)st degree polynomials. Schonhage and Strassen's algorithm was known to be the asymptotically fastest multiplication algorithm until Furer improved upon it in 2007. However, u
APA, Harvard, Vancouver, ISO, and other styles
14

Martins, Carlos Henrique Nascimento. "Estudo e implementação de um analisador de harmônicos variantes no tempo." Universidade Federal de Juiz de Fora (UFJF), 2015. https://repositorio.ufjf.br/jspui/handle/ufjf/4176.

Full text
Abstract:
Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-04-25T17:30:25Z No. of bitstreams: 1 carloshenriquenascimentomartins.pdf: 10221613 bytes, checksum: 0d6eef0f715fc0f9f68bf12a390dcd55 (MD5)<br>Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-04-26T12:22:24Z (GMT) No. of bitstreams: 1 carloshenriquenascimentomartins.pdf: 10221613 bytes, checksum: 0d6eef0f715fc0f9f68bf12a390dcd55 (MD5)<br>Made available in DSpace on 2017-04-26T12:22:24Z (GMT). No. of bitstreams: 1 carloshenriquenascimentomartins.pdf: 10221613 bytes, checksum: 0d6eef0f715fc0f9f
APA, Harvard, Vancouver, ISO, and other styles
15

Barnhart, Samuel. "Design and Development of a Coherent Detection Rayleigh Doppler Lidar System for Use as an Alternative Velocimetry Technique in Wind Tunnels." University of Dayton / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1595276402371536.

Full text
APA, Harvard, Vancouver, ISO, and other styles
16

Madishetty, Suresh. "Design of Multi-Beam Hybrid Digital Beamforming Receivers." University of Akron / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=akron1545178805415923.

Full text
APA, Harvard, Vancouver, ISO, and other styles
17

Sarathy, Vivek. "High Spurious-Free Dynamic Range Digital Wideband Receiver for Multiple Signal Detection and Tracking." Wright State University / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=wright1197910677.

Full text
APA, Harvard, Vancouver, ISO, and other styles
18

Lingenbrink, David Alan Jr. "A New Subgroup Chain for the Finite Affine Group." Scholarship @ Claremont, 2014. http://scholarship.claremont.edu/hmc_theses/55.

Full text
Abstract:
The finite affine group is a matrix group whose entries come from a finite field. A natural subgroup consists of those matrices whose entries all come from a subfield instead. In this paper, I will introduce intermediate sub- groups with entries from both the field and a subfield. I will also examine the representations of these intermediate subgroups as well as the branch- ing diagram for the resulting subgroup chain. This will allow us to create a fast Fourier transform for the group that uses asymptotically fewer opera- tions than the brute force algorithm.
APA, Harvard, Vancouver, ISO, and other styles
19

Logette, Patrice. "Etude et réalisation d'un processeur acousto-optique numérique de traitement des signaux." Valenciennes, 1997. https://ged.uphf.fr/nuxeo/site/esupversions/bbfd31df-2499-46a6-843d-52f346b1db41.

Full text
Abstract:
Un système hybride acousto-optique/numérique axe principalement sur le filtrage F. I. R. A été développé au laboratoire dans le cadre d'une thèse antérieure. L'objet du présent travail est, d'une part, d'améliorer le système existant et, d'autre part, de tester les aptitudes du système ainsi modifié à effectuer d'autres types de calcul. Nous commençons par un résumé des travaux relatifs à l'ancien système, afin de bien positionner le problème. Nous exposons ensuite la conception du nouveau système. Une première partie décrit les modifications des circuits électroniques, avec l'utilisation de c
APA, Harvard, Vancouver, ISO, and other styles
20

Dvořák, Vojtěch. "Implementace výpočtu FFT v obvodech FPGA a ASIC." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2013. http://www.nusl.cz/ntk/nusl-220087.

Full text
Abstract:
The aim of this thesis is to design the implementation of fast Fourier transform algorithm, which can be used in FPGA or ASIC circuits. Implementation will be done in Matlab and then this form of implementation will be used as a reference model for implementation of fast Fourier transform algorithm in VHDL. To verify the correctness ofdesign verification enviroment will be created and verification process wil be done. Program that will generate source code for various parameters of the module performing a fast Fourier transform will be created in the last part of this thesis.
APA, Harvard, Vancouver, ISO, and other styles
21

Rodesten, Stephan. "Program för frekvensanalys." Thesis, Örebro universitet, Institutionen för naturvetenskap och teknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-58157.

Full text
Abstract:
Denna rapport täcker arbetsprocessen bakom att skapa en spektrumanalysator. Läsaren kommer att få läsa om den valda metoden men även alternativa metoder. Utöver detta kommer även de teoretiska delarna bakom varje moment att undersökas samt jämföras med potentiella alternativa lösningar. Projektet har utförts på uppdrag av KA Automation. Syftet med projektet var att skapa en basplattform för analys av ljudfrekvenser. Målet med detta var att kunna identifiera ljudegenskaper i form av frekvenserna hos exempelvis servomotorer i vattenpumpar. Tanken var att i ett senare utvecklingsskede kunna ident
APA, Harvard, Vancouver, ISO, and other styles
22

Chung, Ming-Shen, and 鐘明聲. "FPGA Implementation of the Discrete Fourier Transform (DFT) and the Discrete Cosine Transform (DCT)." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/01456280849939764692.

Full text
Abstract:
碩士<br>國立高雄第一科技大學<br>電腦與通訊工程所<br>90<br>The Discrete Fourier Transform(DFT)has been widely applied in communcation, speech processing, image processing, radar and sonar systems, etc. The architecture of DFT implement can be classified into two fields:(1)one is a pipelined systolic architecture,(2)the other is a memory-based architecture. Discrete Cosine Transform(DCT)has been commonly adopted in the various atandardsfor image compression while FPGA has become a new trend of ASIC design, so we will apply FPGA techinque to implement the DFT and the DCT. This thesis deals with how to use FPGA tech
APA, Harvard, Vancouver, ISO, and other styles
23

Tsai, Fong-Mao, and 蔡豐懋. "Image watermarking based on discrete fractional Fourier transforms." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/08912139702596715078.

Full text
Abstract:
碩士<br>中原大學<br>通訊工程碩士學位學程<br>102<br>In this thesis, to find robust watermarking schemes, we use discrete fractional Fourier transform (DFRFT) and its other four generalized transforms to embed watermarks. They are methods of embedding watermarks in transform domains. In [1], discrete Fractional random transform (DFRNT) was used to embed watermarks. We extend that method and use five transforms to replace DFRNT for watermark embedding and extracting. Then, we attack the watermarked images. The attacks include cropping, salt-and-pepper noise and Gaussian low pass filter. After attacks, we extract
APA, Harvard, Vancouver, ISO, and other styles
24

WU, JIA-LIN, and 吳家麟. "Fast algorithms and architectures for discrete fourier transforms and digital convolutions." Thesis, 1986. http://ndltd.ncl.edu.tw/handle/37367192987084224568.

Full text
APA, Harvard, Vancouver, ISO, and other styles
25

Hsu, Fang-Chii, and 許芳綺. "Efficient Memory Arrangement Methods and VLSI Implementations for Discrete Fourier and Cosine Transforms." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/61599713560978766382.

Full text
Abstract:
碩士<br>國立中山大學<br>資訊工程學系研究所<br>89<br>The thesis proposes using the efficient memory arrangement methods for the implementation of radix-r multi-dimensional Discrete Fourier Transform (DFT) and Discrete Cosine Transform (DCT). By using the memory instead of the registers to buffer and reorder data, hardware complexity is significantly reduced. We use the recursive architecture that requires only one arithmetic-processing element to compute the entire DFT/DCT operation. The algorithm is based on efficient coefficient matrix factorization and data allocation. By exploiting the features of Kronecker
APA, Harvard, Vancouver, ISO, and other styles
26

Bittens, Sina Vanessa. "Sparse Fast Trigonometric Transforms." Doctoral thesis, 2019. http://hdl.handle.net/21.11130/00-1735-0000-0003-C16D-9.

Full text
APA, Harvard, Vancouver, ISO, and other styles
27

Zaeim, Ramin. "Direction of arrival estimation technique for narrow-band signals based on spatial Discrete Fourier Transform." Thesis, 2018. https://dspace.library.uvic.ca//handle/1828/9948.

Full text
Abstract:
This work deals with the further development of a method for Direction of Arrival (DOA) estimation based on the Discrete Fourier Transform (DFT) of the sensor array output. In the existing DFT-based algorithm, relatively high SNR is considered, and it is assumed that a large number of sensors are available. In this study an overview of some of the most commonly used DOA estimation techniques will be presented. Then the performance of the DFT method will be analyzed and compared with the performance of existing techniques. Two main objectives will be studied, firstly the reduction of the numbe
APA, Harvard, Vancouver, ISO, and other styles
28

Chiu, Wei-Ting, and 邱偉庭. "Digital Image Security Applications Based on Discrete Fractional Fourier Transforms and Random Phase Encoding." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/ps58d5.

Full text
Abstract:
碩士<br>中原大學<br>通訊工程碩士學位學程<br>103<br>In this study, we propose an image watermarking algorithm based on discrete fractional Fourier transform (DFRFT) and its extended transforms with random phase encoding (RPE) base on Guo’s method [1]. We also use discrete fractional Fourier transform and its extended transforms with random phase encoding to encrypt double images using Tao’s technology [2].We use multiple-parameter discrete Fourier fractional (MPDFRFT), random discrete fractional Fourier transform (RDFRFT), and real discrete fractional Fourier transform (Real-DFRFT) to replace discrete fraction
APA, Harvard, Vancouver, ISO, and other styles
29

Tai, Yu, and 戴譽. "Applications of Multiple-Parameter Discrete Fractional Fourier Transforms on Digital Image Encryption and Watermarking." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/y84tq2.

Full text
Abstract:
碩士<br>中原大學<br>電機工程研究所<br>106<br>Multiple-parameter discrete fractional Fourier transforms have many free parameters and these parameters can be used as encryption keys that make cryptosystems become more secure. In this thesis, several multiple-parameter discrete fractional Fourier transforms are applied in digital image encryption and watermarking. There are two main topics of digital image encryption including asymmetric double random phase encoding and multiple-image encryption with asymmetric cryptosystem. Asymmetric double random phase encoding is the improved version of double random pha
APA, Harvard, Vancouver, ISO, and other styles
30

Suresh, K. "MDCT Domain Enhancements For Audio Processing." Thesis, 2010. http://etd.iisc.ernet.in/handle/2005/1184.

Full text
Abstract:
Modified discrete cosine transform (MDCT) derived from DCT IV has emerged as the most suitable choice for transform domain audio coding applications due to its time domain alias cancellation property and de-correlation capability. In the present research work, we focus on MDCT domain analysis of audio signals for compression and other applications. We have derived algorithms for linear filtering in DCT IV and DST IV domains for symmetric and non-symmetric filter impulse responses. These results are also extended to MDCT and MDST domains which have the special property of time domain alias canc
APA, Harvard, Vancouver, ISO, and other styles
31

Anoh, Kelvin O. O., N. T. Ali, Hassan S. O. Migdadi, Raed A. Abd-Alhameed, Tahereh S. Ghazaany, Steven M. R. Jones, James M. Noras, and Peter S. Excell. "Performance comparison of MIMO-DWT and MIMO-FrFT multicarrier systems." 2013. http://hdl.handle.net/10454/9607.

Full text
Abstract:
No<br>In this work, we discuss two new multicarrier modulating kernels that can be adopted for multicarrier signaling. These multicarrier transforms are the fractional Forurier transform (FrFT) and discrete wavelet transforms (DWT). At first, we relate the transforms in terms of mathematical relationships, and then using numerical and simulation comparisons we show their performances in terms of bit error ratio (BER) for Multiple Input Multiple Output (MIMO) applications. Numerical results using BPSK and QPSK support that both can be applied for multicarrier signaling, however, it can be resou
APA, Harvard, Vancouver, ISO, and other styles
32

Hulett, David Alexander. "De Fourier a wavelets : un breve recorrido por el análisis tiempo-frecuencia." Bachelor's thesis, 2020. http://hdl.handle.net/11086/15941.

Full text
Abstract:
Tesis (Lic. en Matemática)--Universidad Nacional de Córdoba, Facultad de Matemática, Astronomía, Física y Computación, 2020.<br>Un pequeño tour por el análisis de Fourier. Definimos a la transformada continua de Fourier, presentamos y estudiamos los resultados principales de la serie de Fourier y de la transformada de Fourier discreta. Analizamos cómo hacer la transición de serie a transformada continua y de transformada discreta a la serie. Para estudiar la estructura tiempo-frecuencia de una función presentamos a las transformadas atómicas y estudiamos dos ejemplos: la STFT y la transformada
APA, Harvard, Vancouver, ISO, and other styles
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!