Dissertations / Theses on the topic 'Time correlation functions'
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Alavi, Saman. "Density corrections to transport coefficients from time correlation functions." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape7/PQDD_0019/NQ46308.pdf.
Full textJou, Wen Chi. "The theoretical studies of time-correlation functions with the first principle molecular dynamics simulations on surfaces /." Tamsui : Tamkang University, Department of Chemistry, 2007. http://etds.lib.tku.edu.tw/etdservice/view_metadata?etdun=U0002-0207200714531200.
Full textFreire, Márcio de Melo. "Funções de Green em Mecânica Estatística." reponame:Repositório Institucional da UFC, 2014. http://www.repositorio.ufc.br/handle/riufc/9059.
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Neste trabalho estabeleceremos as definições das funções de Green em mecânica estatística e suas propriedades básicas. Estas funções dependem duplamente do tempo e da temperatura. Isto pode ser observado por meio de suas definições, onde aparecem os valores médios dos produtos de operadores. Neste caso a média é feita sobre o ensemble grão-canônico. Os operadores envolvidos nestas funções satisfazem a equação de movimento de Heisenberg, o que nos permite descrever as equações de evolução para as funções de Green. Por meio da representação espectral das funções de correlação temporal, que é feita através da introdução de uma transformada de Fourier para mudar o sistema do espaço dos tempos para o espaço das frequências, podemos obter as representações espectrais para as funções de Green retardada, avançada e causal. Por último, faremos o uso da função de Green retardada para descrever a condutividade elétrica de um sistema de elétrons submetido a um campo elétrico externo dependente de tempo, em outras palavras, descreveremos o tensor de condutividade elétrica em termos da função de Green retardada e, por último, calcularemos a condutividade elétrica de um sistema de elétrons e fônons.
Brookes, Sarah. "Fluids in Nanopores." Thesis, Griffith University, 2016. http://hdl.handle.net/10072/365467.
Full textThesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Natural Sciences
Science, Environment, Engineering and Technology
Full Text
DeVane, Russell H. "Molecular dynamics and time correlation function theories." [Tampa, Fla.] : University of South Florida, 2005. http://purl.fcla.edu/fcla/etd/SFE0001309.
Full textDe, Silva Weeraddana Manjula Kumara. "Correlation Imaging for Real-time Cardiac MRI." University of Cincinnati / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1471346206.
Full textKasprzyk, Christina Ridley. "Practical applications of molecular dynamics techniques and time correlation function theories." [Tampa, Fla] : University of South Florida, 2006. http://purl.fcla.edu/usf/dc/et/SFE0001644.
Full textRyderfors, Linus. "Two-Photon Excited Fluorescence Depolarisation : Experimental and Theoretical Development." Doctoral thesis, Uppsala University, Department of Photochemistry and Molecular Science, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-9285.
Full textWe have studied fundamental aspects of time-resolved two-photon excited fluorescence depolarisation. The thesis presents experimental as well as theoretical progress. We show that a multi-photon induced instrumental response function obtained from a suspension of gold nanoparticles is appropriate for the analysis of two-photon excited fluorescence decays obtained using time-correlated single photon counting detection. Theoretical expressions have been derived for the fluorescence anisotropy decay obtained upon two-photon excitation of various molecular systems in liquid solutions: a) an anisotropic rigid rotor that undergoes rotational diffusion in the presence of ultrafast unresolved restricted reorientations, e.g. librations. b) a molecular group covalently attached to a stationary macromolecule, and undergoing local reorientation in a uniaxial ordering potential. A new approach to the analysis of two-photon excited fluorescence depolarisation experiments was developed, which combines data obtained by using linearly and circularly polarised excitation light, in a global manner. In the analysis, knowledge about unresolved reorientations was obtained from one-photon excitation studies of the corresponding systems. By means of this procedure it has been possible to obtain quantitative information about the molecular two-photon absorption tensor for perylene and two of its derivatives. Thereby the symmetry of the final excited and intermediate vibronic states could be assigned. The analysis reveals that the two-photon transition studied with the 800 nm laser exhibits mixed character. An important finding from the experiments was that the two-photon absorption tensor appears to be solvent dependent. Furthermore, the thesis presents the first theoretical treatment of two-photon excited donor-donor energy migration in the presence of molecular reorientation and which applies the extended Förster theory. Explicit expressions for molecules that belong to the point groups D2h, D2 and C2v are given. Preliminary experiments are finally also reported on a two-photon excited donor-donor energy migration system consisting of a bisanthryl-bisteroid.
Martins, Marcio Marques. "Influência de parâmetros moleculares em funções de correlação temporal na dinâmica de solvatação mecânica." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2004. http://hdl.handle.net/10183/6896.
Full textIn the present work, we describe our results concerning our molecular dynamics investigation of the mechanical solvation dynamics within the linear response regime in model systems composed by liquid argon with a monoatomic or diatomic solute. The effect of molecular parameters (size, polarizability) and density has been elucidated for various solvation models. Time Correlation Functions for the solvation energy were calculated and separated into n-body (n = 2; 3) contributions distinguishing repulsive and attractive interactions in both liquid systems. In addition, we computed second time derivatives of these functions in order to describe translational, rotational, and roto-translational portions in the solutions containing the diatomics. We found that collective time correlation functions are well described by binary correlations at low liquid densities and, at high densities, ternary correlations become more important producing faster decaying collective time correlation functions due to partial cancellation effects. The repulsive and attractive time correlation functions exhibit a dynamic behavior that is independent on the solvation model due to linear scaling factors that only affect the absolute amplitudes of these functions. In general, the systems involving a rotational degree of freedom furnish smaller correlation times for the collective solvation dynamics, but stronger correlated two-body and three-body terms. Finally, this study shows that the solvation dynamics for the solution containing the diatomics relaxes predominatly by binary translational mechanisms when solvation models involving changes only in the polarizability parameter are considered. Binary attractive rotational mechanism become important in models with changes in the bond length.
Rouhvand, Bahar. "Vesicle-Protein Diffusion and Interaction Study Using Time Resolved Fluorescence Correlation Spectroscopy." University of Akron / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=akron1503261462042903.
Full textBalasubramaniyan, Rajarajeswari. "Gene expression data analysis using novel methods predicting time delayed correlations and evolutionarily conserved functional modules /." [S.l.] : [s.n.], 2005. http://archiv.ub.uni-marburg.de/diss/z2005/0134/.
Full textFransson, Jonas. "Non-Orthogonality and Electron Correlations in Nanotransport : Spin- and Time-Dependent Currents." Doctoral thesis, Uppsala University, Department of Physics, 2002. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-2687.
Full textThe concept of the transfer Hamiltonian formalism has been reconsidered and generalized to include the non-orthogonality between the electron states in an interacting region, e.g. quantum dot (QD), and the states in the conduction bands in the attached contacts. The electron correlations in the QD are described by means of a diagram technique for Hubbard operator Green functions for non-equilibrium states.
It is shown that the non-orthogonality between the electrons states in the contacts and the QD is reflected in the anti-commutation relations for the field operators of the subsystems. The derived forumla for the current contains corrections from the overlap of the same order as the widely used conventional tunneling coefficients.
It is also shown that kinematic interactions between the QD states and the electrons in the contacts, renormalizes the QD energies in a spin-dependent fashion. The structure of the renormalization provides an opportunity to include a spin splitting of the QD levels by polarizing the conduction bands in the contacts and/or imposing different hybridizations between the states in the contacts and the QD for the two spin channels. This leads to a substantial amplification of the spin polarization in the current, suggesting applications in magnetic sensors and spin-filters.
Eklund, Anders. "Computational Medical Image Analysis : With a Focus on Real-Time fMRI and Non-Parametric Statistics." Doctoral thesis, Linköpings universitet, Medicinsk informatik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-76120.
Full textMancini, Lorenzo. "Adiabatic and local approximations for the kohn-sham potential in the hubbard model." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amslaurea.unibo.it/5935/.
Full textHofmanová, Aneta. "Posouzení vybraných ukazatelů společnosti pomocí statistických metod." Master's thesis, Vysoké učení technické v Brně. Fakulta podnikatelská, 2018. http://www.nusl.cz/ntk/nusl-377969.
Full textHuston, Steven Paul. "Structural health monitoring of a high speed naval vessel using ambient vibrations." Thesis, Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/33848.
Full textBukhari, Syed Kalim Hyder. "Heterogeneity, marginal cost and New Keynesian Phillips Curve." Thesis, University of Leicester, 2015. http://hdl.handle.net/2381/35930.
Full textNayyar, Iffat. "Prediction of Optical Properties of Pi-Conjugated Organic Materials for Technological Innovations." Doctoral diss., University of Central Florida, 2013. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/5993.
Full textPh.D.
Doctorate
Physics
Sciences
Physics
Fischer, Michael. "Non-adiabatic quantum molecular dynamics: - Benchmark systems in strong laser fields - Approximate electron-nuclear correlations." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-148848.
Full textMartinho, Carla Alexandra Lopes. "Modelos vectoriais ARMA : estudo e potencialidades." Master's thesis, Instituto Superior de Economia e Gestão, 1997. http://hdl.handle.net/10400.5/21745.
Full textNeste trabalho vai-se proceder ao estudo e à aplicação prática sobre sucessões cronológicas reais dos modelos vectoriais ARMA. Estes modelos generalizam os modelos univariados ARMA e os modelos multivariados de função transferência, tendo vantagem sobre estes últimos porque permitem a análise conjunta de sucessões cronológicas que apresentam efeito de feedback. E de esperar que a modelação conjunta de sucessões potencie a capacidade de as descrever, obtendo-se ganhos significativos em termos previsionais. Deste modo, procerder-se-á ao estudo, com base na análise de dois exemplos concretos, do comportamento dos modelos vectoriais ARMA, conffontando-os com os resultados obtidos pelos modelos univariados e pelos modelos de função transferência.
The aim of this work is to present the methodology of the vectorial ARMA models applied to real time series. These models are generalisations of the univariate ARMA models and of the multivariate transfer function models. The advantage of the vectorial ARMA modelling is to allow the joint analysis of the time series which exhibit feedback effects. It is our intention to show that this joint modelization increases the capacity of describing and forecasting. The application was made with the use of two real examples comparing the results ffom the vectorial ARMA, the univariate and the transfer function modelling.
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Freire, MÃrcio de Melo. "FunÃÃes de Green em mecÃnica estatÃstica." Universidade Federal do CearÃ, 2014. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=12311.
Full textNeste trabalho estabeleceremos as definiÃÃes das funÃÃes de Green em mecÃnica estatÃstica e suas propriedades bÃsicas. Estas funÃÃes dependem duplamente do tempo e da temperatura. Isto pode ser observado por meio de suas definiÃÃes, onde aparecem os valores mÃdios dos produtos de operadores. Neste caso a mÃdia à feita sobre o ensemble grÃo-canÃnico. Os operadores envolvidos nestas funÃÃes satisfazem a equaÃÃo de movimento de Heisenberg, o que nos permite descrever as equaÃÃes de evoluÃÃo para as funÃÃes de Green. Por meio da representaÃÃo espectral das funÃÃes de correlaÃÃo temporal, que à feita atravÃs da introduÃÃo de uma transformada de Fourier para mudar o sistema do espaÃo dos tempos para o espaÃo das frequÃncias, podemos obter as representaÃÃes espectrais para as funÃÃes de Green retardada, avanÃada e causal. Por Ãltimo, faremos o uso da funÃÃo de Green retardada para descrever a condutividade elÃtrica de um sistema de elÃtrons submetido a um campo elÃtrico externo dependente de tempo, em outras palavras, descreveremos o tensor de condutividade elÃtrica em termos da funÃÃo de Green retardada e, por Ãltimo, calcularemos a condutividade elÃtrica de um sistema de elÃtrons e fÃnons.
Shalaginova, Daria. "Posouzení vybraných ukazatelů společnosti pomocí statistických metod." Master's thesis, Vysoké učení technické v Brně. Fakulta podnikatelská, 2020. http://www.nusl.cz/ntk/nusl-414494.
Full textTurisová, Alena. "Posouzení vybraných ukazatelů pomocí analýzy časových řad." Master's thesis, Vysoké učení technické v Brně. Fakulta podnikatelská, 2017. http://www.nusl.cz/ntk/nusl-317063.
Full textHourany, Karl. "Contribution à l'exploitation du bruit ambiant pour le contrôle santé intégré passif des barres et des tubes." Thesis, Valenciennes, 2015. http://www.theses.fr/2015VALE0039/document.
Full textThe works presented in this manuscript are based on previous studies conducted at the Institute of Electronics Microelectronics and Nanotechnology of the University of Valenciennes and Hainaut Cambrésis. They concern the development of an embedded monitoring system for the control of materials and structures used in different transport domains (pipeline, aerospace, railway ...). This is the Structural Health-Monitoring principle. The idea is to integrate sensors into the surfaces of the controlled structures in order to achieve a non-destructive control system for the control of the latter during their entire lifetime. First the work done at the laboratory in this domain, are illustrated, some definitions such as ultrasonic waves, the Non Destructive Testing and the Structural Health Monitoring are recalled, to switch later to the explanation of the passage from an active control to a passive control. In a second step, an images comparison algorithm based on the local minima present in these images has been proposed and tested on simple images of sixteen pixels and was used to test the degree of resemblance between them. The explanation of the developed algorithm is divided into two parts. In the first one, we explain how to extract the local minima of an image. The second part describes the procedure for determining the rate of resemblance between the images. The simulation of the propagation of a signal in a reverberant plate and the obtaining of the frequency time images corresponding to filtered correlation (autocorrelation) has been described. The algorithm was validated on those images allowing the localization of an unknown source position
Ricci, Lorenzo. "Essays on tail risk in macroeconomics and finance: measurement and forecasting." Doctoral thesis, Universite Libre de Bruxelles, 2017. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/242122.
Full textDoctorat en Sciences économiques et de gestion
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Allam, Lévi. "Etude de la diffusion unidimensionnelle dans les chaines finies : application au tmmc-cd." Toulouse 3, 1987. http://www.theses.fr/1987TOU30063.
Full textDejean, de La Batie Rémi. "Etude des mouvements moléculaires dans les polymères en masse par résonance magnétique nucléaire du 13c et simulation de Monte-Carlo." Paris 6, 1986. http://www.theses.fr/1986PA066284.
Full textHunter, Brandon. "Channel Probing for an Indoor Wireless Communications Channel." BYU ScholarsArchive, 2003. https://scholarsarchive.byu.edu/etd/64.
Full textSmith, Kyle Kurt Gabriel. "Approximate quantum dynamics methods for time correlation functions." Thesis, 2014. http://hdl.handle.net/2152/24986.
Full texttext
(10712730), Zizhuang Wu. "Non-Fully Symmetric Space-Time Matern-Cauchy Correlation Functions." Thesis, 2021.
Find full textKegerreis, Jeb Stuart. "Quantum mechanical calculations of time correlation functions for neat fluids /." 2009. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3362936.
Full textSource: Dissertation Abstracts International, Volume: 70-06, Section: B, page: 3526. Adviser: Nancy Makri. Includes bibliographical references. Available on microfilm from Pro Quest Information and Learning.
Tsai, Yu-An, and 蔡宇安. "Non-Markovain Two-Time correlation functions: Exact Result v.s Perturbation Approach." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/22443886533994020497.
Full text國立臺灣大學
物理研究所
99
A two-level system which decays spontaneously into field vacuum is studied through the Jaynes-Cummings model in the rotating wave approximation (RWA).When at most one excitation is considered, this model is exactly solvable. Here we evaluate the non-Markovian two-time correlation functions (CF''s) of system operators for this model in two ways: one by directly solving the system-environment evolution,and the other by using the perturbative time-convolutionless non-Markovian master equation approach. We derive valid to fourth order in system-bath coupling strength a non-Markovain evolution equation for the two-time CF''s of system operators. We use the derived evolution equation to calculate a two-time CF for the two-level model and compare it with the exact result obtained by direct evaluation. Another numerical series acceleration method is applied to the calculation of the perturbation decay, and this method is found to improve the accuracy of the evolution equation. The result obtained by the derived perturbative two-time evolution equation is much better than those by the perturbative Markovian Quantum regression theorem(QRT), the non-Markovian QRT and exact QRT as it agrees more closely with the exact result even when the model is in the regime where the bath correlation time is comparable to the system relaxation time.This demonstrates the validity and usefulness of our derived non-Markovain two-time evolution equation. The exact spontaneous emission spectrum is also calcukated, and it has very different behaviours in the strong coupling an the weak coupling regions.
Wang, Yu-Jen, and 王佑仁. "Quantum Correction on Bath Time-Correlation Functions: Applications on Excitation Energy Transfer Dynamics." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/x3k6pc.
Full text國立臺灣大學
化學研究所
106
Quantum correction is necessary when calculating dissipative quantum dynamics based on results from classical molecular dynamics simulation in which quantum effects are ignored. Quantum correction has been used in many fields to make use of classical trajectories in quantum simulations, such as calculation of infrared spectra. However, in the context of excitation energy transfer in molecular system, the need of applications of quantum corrections is less discussed. In this study, we examine four quantum correction methods, including the Harmonic method and the Standard method proposed by other groups previously, and the Fitting method and the Prony method proposed by us. We aim to elucidate the performance of the correction by the four correc- tion methods in order to properly apply them to simulating excitation energy transfer dynamics. We focus on a model that describes a two-level system linearly coupled to a harmonic bath to explore the applicability of quantum correction methods in various parameter conditions. Our results reveal the necessity of applying quantum correction when studying excitation energy transfer dynamics based on results of classical molecular dynamics simula- tion. Our calculations also conclude that the Harmonic method performs the best among the four approaches and that the Prony method has serious draw- backs. The Fitting method provides similar results as the Standard method, and both methods perform well at a higher temperature or in the condition where relaxation is driven by coherent evolution.
Chou, Wen-Chi, and 周文祺. "The theoretical studies of time-correlation functions with the first principle molecular dynamics simulations on surfaces." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/98002793656230998703.
Full text淡江大學
化學學系博士班
95
We successfully developed a series of IR spectrum simulation and corresponding spectrum analysis methods for studying the vibrational dynamics and the reaction dynamics of both molecular and surface systems. The time-correlation function theories were thoroughly studied to build 1) the Fourier trnsformed dipole-moment AutoCorrelation Function(dpACF) for IR spectrum simulation, 2) the Partial Dipole-moment AutoCorrelatoin Function(PaDAF) and the Structural Coordinate AutoCorrelation Function(SCAF) schemes for spectrum analysis, and 3) the Fourier transformed anisotropic dpACF for the IR spectrum simulations on surface systems. By utilizing Density Functional Theory in connection with accurate LCAO basis sets and norm-conserving pseudopotentials, efficient Born-Oppenheimer molecular dynamics(BOMD) simulations would thereby be performed to study the reaction dynamics of adsorbed molecules on surfaes at microscopic level. First of all, our IR spectrum simulation methods were validated by calculating the IR spectra of a series of organic molecules. Based on the success of IR spectrum simulations on gas-phase molecules, furthermore, we employed this IR spectrum simulation and analysis scheme to Si(100) clean surface, monohydride saturated Si(100) surface, i.e. H-Si(100)-2x1 surface, adsorbed styrenes on Si(100) surfaces, and adsorbed one dimensional(1-D) styrene molecular wire on Si(100) surface. Spectrum simulation results for these surface systems are also qualitatively consistent with experimental measurements. In addition, we also successfully studied the reaction dynamics, Partial Density of States(PDOS) evolutions, and the vibrational dynamics within several picoseconds for two kinds of surface reactions of adsorbed styrene on Si(100) surface, say, (1) the [2+2] cycloaddition of styrene on Si(100), and (2) the self-directed growth of 1-D styrene molecular wire on Si(100) via the H-abstraction reaction. On the other hand, we also calculated the transition state structures and their corresponding PDOS variations, however, our results show that the one dimensionality of styrene molecular wire is due to two possible lower energy barrier pathways of H-abstraction along dimer row direction. Finally, we also studied the effects on both IR spectrum of H-Si(100) and the charge dynamics of styrene-Si(100)-H under external electric field. The results show that the H-Si vibrational frequency could be red-shifted or blue-shifted under the presence of external electric field along surface normal, depending on the direction of the electric field. Charge redistribution dynamics of styrene-Si(100)-H accompanying the structure relaxation within 250 femtoseconds were also observed after turning on the external electric field.
Kuo, Hua-Cheng, and 郭華丞. "The Time Correlation Function in Single Electron Tunneling." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/14938511834529623079.
Full text廖婉婷. "Correlation between functional MRI signal and reaction time." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/89359377332770651949.
Full text國立清華大學
原子科學系
90
Functional magnetic resonance imaging (fMRI) detects hemodynamic responses with high spatial and temporal resolution. Capabilities of correlating psychophysical parameters with fMRI allow a better understanding of the neuronal processes. The objective of this study is to examine how fMRI BOLD response parameters vary with behavioral outcome measures (e.g. reaction time). We utilized a lexical decision task with two character-frequency levels and pseudocharaters. In the left inferior frontal lobe, the activation volumes were smaller to high-frequency characters than to low-frequency characters and pseudocharacters (587±261 vs. 3280±822 mm3, 587±261 vs. 2025±548 mm3 ), which is correlated well with the reaction times (417±9 vs. 631±22 ms, 417±9 vs. 658±15 ms ). The linear correlation between the measured reaction times and FWHM (full width half maximum) of the fMRI responses was also observed in the left inferior frontal lobe (p<0.001). There was no significant correlation between reaction time and onset time of the hemodynamic response. These findings imply left inferior frontal lobe is active during the entire reaction time when executing the lexical decision task. Conversely, the FWHM of fMRI responses in the left primary motor cortex (M1) related to pressing a button for responding at the end of task is not correlated to reaction time. Our results are also coherent with respect to a functional model of lexical decision task. Thus, the different patterns of neuronal activity during the cognitive process could be detected and distinguished through the fMRI hemodynamic responses. In this study, we have demonstrated that the time-resolved fMRI technique has the capacity to exploit the cognitive events by tracing in the temporal responses of fMRI, even if the reaction time is at the time scale of hundred milliseconds.
Sebatjane, Phuti. "Understanding patterns of aggregation in count data." Diss., 2016. http://hdl.handle.net/10500/22067.
Full textStatistics
M.Sc. (Statistics)
Hsu, Chih-Chi, and 許植棋. "Orientational time correlation function of liquid water : fourth cumulant." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/7deptd.
Full text國立交通大學
物理研究所
102
In this thesis, with the SPC/E model of liquid water, I extent the calculations for the orientational correlation function (OCF) up to the fourth cumulant expansion. By the instantaneous normal mode (INM) theory or the power spectra of the angular velocity autocorrelation function (AVAF), we predict the behavior of the OCFs in the short and long time regimes and estimate the time scales for different regimes by using the asymptotic functions of the cumulant expansion. Besides, by Voronoi polyhedra (VP) analysis for liquids generated with classical MD simulations, we study the local-structure effects on the OCFs of this water model. In the short-time regime, the OCFs is a Gaussian decay, no matter what kind of rotational spectrum is used for calculation. In the long-time regime, the behavior of the OCFs predicted by the second cumulant expansion is a single exponential decay calculated with the AVAF spectrum and a logarithmic divergence calculated with the stable-INM spectrum. Up to the fourth cumulant expansion, the long-rime behavior of the OCFs calculated with the stable-INM spectrum agrees well with the results of MD simulation.
CHEN, YUEH-FU, and 陳岳甫. "Examining the Correlation Between Accommodative Function and Time Duration of Smartphone Usage." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/k39dh7.
Full text中臺科技大學
生物科技暨醫學工程研究所
106
Introduction In recent years, the smartphone has become increasingly popular over traditional desktop PC or laptop due to its convenience of use and portability. However, as with traditional video display screens, which can cause a variety of visual symptoms when used in prolonged period of time, the greater frequency of mobile device usage in today’s digital savvy world also prompted an array of visual symptoms and much more. Digital eye strain related to electronic displays affect visual functions that include accommodation and vergence. However, investigation into the accommodative effect of smartphone use with time has not been thoroughly studied before. In this work, we set out to perform a better controlled experiment to examine the correlation between duration of smartphone use and accommodative functions. Method A total of 31 normal subjects were enrolled in this prospective study to test for accommodative amplitude, response, and facility using a specially designed chin apparatus to minimize inaccuracies in the measurements. Accommodative functions were tested with minus lens to blur, monocular estimation method (MEM), and monocular flipper test after 10, 20, and 30 minutes of smartphone use on separate occasions. Subjective data were collected in form of visual discomfort survey before and after each testing period. Results and Discussion The monocular accommodative amplitude was significantly decreased while visual discomfort increased after smartphone use for 10, 20 and 30 minutes. The accommodative lag after smartphone work was also significantly greater after 20 and 30 minutes of smartphone use. Accommodative facility did not changed significantly after smartphone use for each time period tested. Visual discomfort was not found to be correlated to a decrease in accommodative functions, but may be related to dry eye or binocular vision function. Conclusion After 10 minutes of smartphone use, accommodative function and visual comfort were affected, which means that the 20/20/20 rule may not be a suitable health tip to alleviate the health burden caused by smartphone usage. Therefore, a new health recommendation should be tailored to the smartphone, which exerts more stress and requires greater demands on the visual system than the traditional digital monitors or displays.
Pai, Yu-Fan, and 白馭帆. "The time series analysis of human heart rate — the application of partial auto-correlation function and intervention models." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/21403947985615865228.
Full text東海大學
統計學系
97
This research applied the time series analysis to the data of human heartbeat. The main purpose of this research was to investigate the auto-correlation of heartbeat under steady conditions and the level of increase in heartbeat under external stimuli. The heartbeat data of patients with autonomic neuropathy and normal people were used. Partial autocorrelation function and intervention model were used to estimate the autocorrelation of heartbeat and the level of increase in heartbeat under stimuli, and the results served to distinguish between patients with autonomic neuropathy and normal people. According to the analysis, the values of the second order partial autocorrelation function of normal people were mostly significantly negative and those of patients were not. The heartbeat time series data of normal people were best described by mixed autoregressive moving average processes while those of patients were modeled as autoregressive processes. The magnitude of increase in heartbeat in normal people when external stimuli were applied was significantly larger than that of patients. The above results may provide an alternative way for determining whether subjects suffer from autonomic neuropathy.
Kudela, Maria Aleksandra. "Statistical methods for high-dimensional data with complex correlation structure applied to the brain dynamic functional connectivity studyDY." Diss., 2017. http://hdl.handle.net/1805/12835.
Full textA popular non-invasive brain activity measurement method is based on the functional magnetic resonance imaging (fMRI). Such data are frequently used to study functional connectivity (FC) defined as statistical association among two or more anatomically distinct fMRI signals (Friston, 1994). FC has emerged in recent years as a valuable tool for providing a deeper understanding of neurodegenerative diseases and neuropsychiatric disorders, such as Alzheimer's disease and autism. Information about complex association structure in high-dimensional fMRI data is often discarded by a calculating an average across complex spatiotemporal processes without providing an uncertainty measure around it. First, we propose a non-parametric approach to estimate the uncertainty of dynamic FC (dFC) estimates. Our method is based on three components: an extension of a boot strapping method for multivariate time series, recently introduced by Jentsch and Politis (2015); sliding window correlation estimation; and kernel smoothing. Second, we propose a two-step approach to analyze and summarize dFC estimates from a task-based fMRI study of social-to-heavy alcohol drinkers during stimulation with avors. In the first step, we apply our method from the first paper to estimate dFC for each region subject combination. In the second step, we use semiparametric additive mixed models to account for complex correlation structure and model dFC on a population level following the study's experimental design. Third, we propose to utilize the estimated dFC to study the system's modularity defined as the mutually exclusive division of brain regions into blocks with intra-connectivity greater than the one obtained by chance. As a result, we obtain brain partition suggesting the existence of common functionally-based brain organization. The main contribution of our work stems from the combination of the methods from the fields of statistics, machine learning and network theory to provide statistical tools for studying brain connectivity from a holistic, multi-disciplinary perspective.
Fleig, Timo [Verfasser]. "Wave function based relativistic multi-reference electron correlation methods : development and application to atomic and molecular properties / Timo Fleig." 2007. http://d-nb.info/984672672/34.
Full textBalasubramaniyan, Rajarajeswari [Verfasser]. "Gene expression data analysis using novel methods : predicting time delayed correlations and evolutionarily conserved functional modules / vorgelegt von Rajarajeswari Balasubramaniyan." 2005. http://d-nb.info/976420724/34.
Full textFischer, Michael. "Non-adiabatic quantum molecular dynamics: - Benchmark systems in strong laser fields - Approximate electron-nuclear correlations: Non-adiabatic quantum molecular dynamics: - Benchmark systems in strong laser fields - Approximate electron-nuclear correlations." Doctoral thesis, 2013. https://tud.qucosa.de/id/qucosa%3A28198.
Full textKoubek, Antonín. "Bodové procesy v čase a prostoru." Master's thesis, 2013. http://www.nusl.cz/ntk/nusl-320988.
Full textGhosh, Siddharth. "Nanoscale Photonics." Doctoral thesis, 2016. http://hdl.handle.net/11858/00-1735-0000-0023-3ED4-2.
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