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Patterson, Brett Alexander. "Maximum entropy data analysis." Thesis, University of Cambridge, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.240969.
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Purahoo, K. "Maximum entropy data analysis." Thesis, Cranfield University, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.260038.
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Karamanos, Konstantinos. "Entropy analysis of nonequilibrium systems." Doctoral thesis, Universite Libre de Bruxelles, 2002. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/211390.
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Schwill, Stephan. "Entropy analysis of financial time series." Thesis, University of Manchester, 2016. https://www.research.manchester.ac.uk/portal/en/theses/entropy-analysis-of-financial-time-series(7e0c84fe-5d0b-41bc-96c6-5e41ffa5b8fe).html.
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This thesis applies entropy as a model independent measure to address research questions concerning the dynamics of various financial time series. The thesis consists of three main studies as presented in chapters 3, 4 and 5. Chapters 3 and 4 apply an entropy measure to conduct a bivariate analysis of drawdowns and drawups in foreign exchange rates. Chapter 5 investigates the dynamics of investment strategies of hedge funds using entropy of realised volatility in a conditioning model. In all three studies, methods from information theory are applied in novel ways to financial time series. As Information Theory and its central concept of entropy are not widely used in the economic sciences, a methodology chapter was therefore included in chapter 2 that gives an overview on the theoretical background and statistical features of the entropy measures used in the three main studies. In the first two studies the focus is on mutual information and transfer entropy. Both measures are used to identify dependencies between two exchange rates. The chosen measures generalise, in a well defined manner, correlation and Granger causality. A different entropy measure, the approximate entropy, is used in the third study to analyse the serial structure of S&P realised volatility. The study of drawdowns and drawups has so far been concentrated on their uni- variate characteristics. Encoding the drawdown information of a time series into a time series of discrete values, Chapter 3 uses entropy measures to analyse the correlation and cross correlations of drawdowns and drawups. The method to encode the drawdown information is explained and applied to daily and hourly EUR/USD and GBP/USD exchange rates from 2001 to 2012. For the daily series, we find evidence of dependence among the largest draws (i.e. 5% and 95% quantiles), but it is not as strong as the correlation between the daily returns of the same pair of FX rates. There is also dependence between lead/lagged values of these draws. Similar and stronger findings were found among the hourly data. We further use transfer entropy to examine the spill over and lead-lag information flow between drawup/drawdown of the two exchange rates. Such information flow is indeed detectable in both daily and hourly data. The amount of information transferred is considerably higher for the hourly than the daily data. Both daily and hourly series show clear evidence of information flowing from EUR/USD to GBP/USD and, slightly stronger, in the reverse direction. Robustness tests, using effective transfer entropy, show that the information measured is not due to noise. Chapter 4 uses state space models of volatility to investigate volatility spill overs between exchange rates. Our use of entropy related measures in the investigation of dependencies of two state space series is novel. A set of five daily exchange rates from emerging and developed economies against the dollar over the period 1999 to 2012 is used. We find that among the currency pairs, the co-movement of EUR/USD and CHF/USD volatility states show the strongest observed relationship. With the use of transfer entropy, we find evidence for information flows between the volatility state series of AUD, CAD and BRL.Chapter 5 uses the entropy of S&P realised volatility in detecting changes of volatility regime in order to re-examine the theme of market volatility timing of hedge funds. A one-factor model is used, conditioned on information about the entropy of market volatility, to measure the dynamic of hedge funds equity exposure. On a cross section of around 2500 hedge funds with a focus on the US equity markets we find that, over the period from 2000 to 2014, hedge funds adjust their exposure dynamically in response to changes in volatility regime. This adds to the literature on the volatility timing behaviour of hedge fund manager, but using entropy as a model independent measure of volatility regime. Finally, chapter 6 summarises and concludes with some suggestions for future research.
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Krempa, Peter. "Analysis of Entropy Levels in the Entropy Pool of Random Number Generator." Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2013. http://www.nusl.cz/ntk/nusl-236179.
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V informatice je pojem entropie obvykle znám jako nahodný proud dat. Tato práce krátce shrnuje metody generovaní nahodných dat a popisuje generátor náhodnych čísel, jež je obsažen v jádře operačního systému Linux. Dále se práce zabývá určením bitové rychlosti generování nahodných dat tímto generátorem ve virtualizovaném prosředí, které poskytují různé hypervizory. Práce popíše problémy nízkého výkonu generátory nahodných dat ve virtualním prostředí a navrhne postup pro jejich řešení. Poté je nastíňena implementace navržených postupů, které je podrobena testům a její vysledky jsou porovnány s původním systémem. Systém pro distribuci entropie může dále vylepšit množství entropie v sytémovém jádře o několik řádu, pokud je připojen k vykonému generátoru nahodných dat.
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Robinson, David Richard Terence. "Developments in maximum entropy data analysis." Thesis, University of Cambridge, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.307063.
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McLean, Andrew Lister. "Applications of maximum entropy data analysis." Thesis, University of Southampton, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.319161.
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Garvey, Jennie Hill. "Independent component analysis by entropy maximization (infomax)." Thesis, Monterey, Calif. : Naval Postgraduate School, 2007. http://bosun.nps.edu/uhtbin/hyperion-image.exe/07Jun%5FGarvey.pdf.
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Thesis (M.S. in Electrical Engineering)--Naval Postgraduate School, June 2007.Thesis Advisor(s): Frank E. Kragh. "June 2007." Includes bibliographical references (p. 103). Also available in print.
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Gärtner, Joel. "Analysis of Entropy Usage in Random Number Generators." Thesis, KTH, Skolan för datavetenskap och kommunikation (CSC), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-214567.
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Cryptographically secure random number generators usually require an outside seed to be initialized. Other solutions instead use a continuous entropy stream to ensure that the internal state of the generator always remains unpredictable. This thesis analyses four such generators with entropy inputs. Furthermore, different ways to estimate entropy is presented and a new method useful for the generator analysis is developed. The developed entropy estimator performs well in tests and is used to analyse entropy gathered from the different generators. Furthermore, all the analysed generators exhibit some seemingly unintentional behaviour, but most should still be safe for use.Kryptografiskt säkra slumptalsgeneratorer behöver ofta initialiseras med ett oförutsägbart frö. En annan lösning är att istället konstant ge slumptalsgeneratorer entropi. Detta gör det möjligt att garantera att det interna tillståndet i generatorn hålls oförutsägbart. I den här rapporten analyseras fyra sådana generatorer som matas med entropi. Dessutom presenteras olika sätt att skatta entropi och en ny skattningsmetod utvecklas för att användas till analysen av generatorerna. Den framtagna metoden för entropiskattning lyckas bra i tester och används för att analysera entropin i de olika generatorerna. Alla analyserade generatorer uppvisar beteenden som inte verkar optimala för generatorns funktionalitet. De flesta av de analyserade generatorerna verkar dock oftast säkra att använda.
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Mujumdar, Anusha Pradeep. "Cross entropy-based analysis of spacecraft control systems." Thesis, University of Exeter, 2016. http://hdl.handle.net/10871/28006.
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Space missions increasingly require sophisticated guidance, navigation and control algorithms, the development of which is reliant on verification and validation (V&V) techniques to ensure mission safety and success. A crucial element of V&V is the assessment of control system robust performance in the presence of uncertainty. In addition to estimating average performance under uncertainty, it is critical to determine the worst case performance. Industrial V&V approaches typically employ mu-analysis in the early control design stages, and Monte Carlo simulations on high-fidelity full engineering simulators at advanced stages of the design cycle. While highly capable, such techniques present a critical gap between pessimistic worst case estimates found using analytical methods, and the optimistic outlook often presented by Monte Carlo runs. Conservative worst case estimates are problematic because they can demand a controller redesign procedure, which is not justified if the poor performance is unlikely to occur. Gaining insight into the probability associated with the worst case performance is valuable in bridging this gap. It should be noted that due to the complexity of industrial-scale systems, V&V techniques are required to be capable of efficiently analysing non-linear models in the presence of significant uncertainty. As well, they must be computationally tractable. It is desirable that such techniques demand little engineering effort before each analysis, to be applied widely in industrial systems. Motivated by these factors, this thesis proposes and develops an efficient algorithm, based on the cross entropy simulation method. The proposed algorithm efficiently estimates the probabilities associated with various performance levels, from nominal performance up to degraded performance values, resulting in a curve of probabilities associated with various performance values. Such a curve is termed the probability profile of performance (PPoP), and is introduced as a tool that offers insight into a control system's performance, principally the probability associated with the worst case performance. The cross entropy-based robust performance analysis is implemented here on various industrial systems in European Space Agency-funded research projects. The implementation on autonomous rendezvous and docking models for the Mars Sample Return mission constitutes the core of the thesis. The proposed technique is implemented on high-fidelity models of the Vega launcher, as well as on a generic long coasting launcher upper stage. In summary, this thesis (a) develops an algorithm based on the cross entropy simulation method to estimate the probability associated with the worst case, (b) proposes the cross entropy-based PPoP tool to gain insight into system performance, (c) presents results of the robust performance analysis of three space industry systems using the proposed technique in conjunction with existing methods, and (d) proposes an integrated template for conducting robust performance analysis of linearised aerospace systems.
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Maia, Maria de Lourdes Oliveira. "Sintese e otimização de sistemas de destilação utilizando a analise exergetica." [s.n.], 2001. http://repositorio.unicamp.br/jspui/handle/REPOSIP/267503.
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Orientador: Roger Josef ZemTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica
Made available in DSpace on 2018-07-29T01:55:29Z (GMT). No. of bitstreams: 1 Maia_MariadeLourdesOliveira_D.pdf: 6396882 bytes, checksum: b0a06b7f265dff67b45f506f542329d9 (MD5) Previous issue date: 2001
Resumo: Sistemas de destilação são amplamente utilizados em indústrias químicas e petroquímicas. Uma desvantagem desses sistemas, no entanto, é o fato dos mesmos apresentarem um grande consumo de energia. Dessa forma, a identificação de parâmetros como: refluxo mínimo, condição térmica da alimentação, posição do estágio da alimentação, etc., são extremamente importantes tanto para o projeto de colunas de destilação isoladas, como também para o seqüenciamento de colunas de destilação com reduzido consumo de energia. Visando a redução do consumo de energia de processos, a análise exergética tem sido amplamente utilizada. Por meio do cálculo do conteúdo de exergia das correntes do processo, é possível ter-se uma idéia da degradação da energia ao longo do mesmo. A medida da qualidade da energia é a exergia. O objetivo da análise exergética de processos é identificar as fontes de irreversibilidade, ou perda de exergia, e também identificar as modificações no processo que podem levar à redução dessa perda. Como resultado tem-se um menor consumo de energia. Somente recentemente, no entanto, a análise exergética tem sido aplicada a processos químicos. Como exemplo tem-se a metodologia proposta por Zemp (1994) na qual a seqüência ótima de colunas de destilação é a identificada como sendo a que apresenta menor perda de exergia. Uma desvantagem dessa metodologia, no entanto, é que a condição térmica da alimentação é fixada em líquido saturado. Neste trabalho, a análise exergética é utilizada na síntese e otimização de sistemas de destilação. Numa primeira etapa, o conceito de perfil quase-reversível para a separação de misturas multicomponentes em colunas de destilação isoladas foi utilizado, juntamente com a análise exergética, para a otimização da condição térmica da alimentação. Os bons resultados obtidos para vários sistemas motivaram a continuação do estudo em direção ao sequenciamento de colunas de destilação. O objetivo foi o de investigar se a otimização da condição térmica pode reduzir ainda mais o consumo de energia da seqüência previamente identificada como ótima. Modificação na pressão de operação das colunas da seqüência, assim como a influência da composição da alimentação, também foram consideradas. V ários sistemas com diferentes número de componentes foram utilizados para testar a metodologia. No caso dos sistemas temários, ambas as opções de seqüência foram estudadas. Os resultados provaram que a otimização das colunas não modifica a seqüência identificada como ótima. De uma maneira geral, foi possível propor uma metodologia para a síntese e otimização de sistema de destilação sem a necessidade da simulação rigorosa das colunas. Como vantagem tem-se o fato de que problemas de convergência não aparecem e não há a necessidade de se determinar o estágio da alimentação à priori
Abstract: Distillation systems are widely used in chemical and petrochemical industries. The main drawback of these systems, however, is the fact that they are energy intensive processes. Therefore, there is a need of a methodology that allows for the synthesis of distillation systems that present low energy consumption. In this sense, the correct identification of parameters such as: minimum reflux, feed stage location, etc plays an important role. In order to reduce the energy consumption of processes, the exergy analysis has appeared as an efficient too1. By computing the exergy content of the process streams the design engineer can understand how the energy degrades throughout the processo Exergy is a measurement of the quality of the energy. The goal of the exergy analysis is to identify sources of exergy losses, and the most appropriate modifications that will 1ead to the decrease of process irreversibility. As a result, the energy requirement of the process is reduced. Only recently, however, exergy analysis has been applied to chemical processo The optimum distillation column sequence, for example, was identified as the one that presents the lowest value of the minimum exergy loss (Zemp, 1994). However, the feed thermal condition is fixed as saturated liquido. In this work, exergy analysis is applied to the synthesis and optimisation of distillation columns sequences. Firstly, the concept of near-reversible column profile, together with the exergy analysis, were used to optimise the feed thermal condition of the feed. Secondly, it was investigated if different feed thermal condition can further reduce the overall energy consumption of a sequence. Not only were considered changes in the feed condition but it was also analysed other modifications in the operational conditions of each column of the sequence. The influence of the composition of the feed was tested as well. Several systems with different number of components were used to test the methodology. For the temary systems both direct and indirect separation were analysed. Results have shown that the optimisation of the columns do not change the selected optimum sequence. Overall, the exergy analysis applied to distillation systems has shown to be a useful tool to the synthesis and optimisation of such separation systems. By using the proposed methodology there is no need to resort to the rigorous simulation of each column of the sequence. Therefore, convergence problems as well as the tedious trial-and-error procedure for the determination of the optimal feed tray location are avoided.
Doutorado
Sistemas de Processos Quimicos e Informatica
Doutor em Engenharia Química
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Kobo, Nomkwezane Sanny. "Entropy analysis of a reactive variable viscosity channel flow." Thesis, [S.l. : s.n.], 2009. http://dk.cput.ac.za/cgi/viewcontent.cgi?article=1058&context=td_cput.
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Jamasebi, Reza. "COMPUTATIONAL PHENOTYPE DERIVED FROM PHYSIOLOGICAL TIME SERIES: APPLICATION TO SLEEP DATA ANALYSIS." Case Western Reserve University School of Graduate Studies / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=case1220467153.
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Uchimoto, Kiyotaka. "Maximum Entropy Models for Japanese Text Analysis and Generation." 京都大学 (Kyoto University), 2004. http://hdl.handle.net/2433/147595.
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Orange, Nicholas Brian. "Transfer Entropy Analysis of the Interactions of Flying Bats." Thesis, Virginia Tech, 2015. http://hdl.handle.net/10919/53955.
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In this document, a low-cost, portable, non-invasive method of collecting the 3D trajectories of flying bats is first presented. An array of commercially available camera and light components is used alongside a number of well-established calibration and triangulation techniques to resolve the motion of agents through a 3D volume. It is shown that this system is capable of accurately capturing the bats' flight paths in a field experiment. The use of non-visible illumination ensures that a natural cave environment is disturbed as little as possible for behavioral experiments.
Following is a transfer entropy analysis approach applied to the 3D paths of bats flying in pairs. The 3D trajectories are one-dimensionally characterized as inverse curvature time series to allow for entropy calculations. In addition to a traditional formulation of information flow between pair members, a path coupling hypothesis is pursued with time-delay modifications implemented in such a way as to not change the Markovianity of the process. With this modification, trends are found that suggest a leader-follower interaction between the front bat and the rear bat, although statistical significance is not reached due to the small number of pairs considered.Master of Science
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Woodcock, Dan. "A novel entropy measure for analysis of the electrocardiogram." Thesis, Aston University, 2007. http://publications.aston.ac.uk/10681/.
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There has been much recent research into extracting useful diagnostic features from the electrocardiogram with numerous studies claiming impressive results. However, the robustness and consistency of the methods employed in these studies is rarely, if ever, mentioned. Hence, we propose two new methods; a biologically motivated time series derived from consecutive P-wave durations, and a mathematically motivated regularity measure. We investigate the robustness of these two methods when compared with current corresponding methods. We find that the new time series performs admirably as a compliment to the current method and the new regularity measure consistently outperforms the current measure in numerous tests on real and synthetic data.
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Yi, Ju Y. "Definition and Construction of Entropy Satisfying Multiresolution Analysis (MRA)." DigitalCommons@USU, 2016. https://digitalcommons.usu.edu/etd/5057.
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This paper considers some numerical schemes for the approximate solution of conservation laws and various wavelet methods are reviewed. This is followed by the construction of wavelet spaces based on a polynomial framework for the approximate solution of conservation laws. Construction of a representation of the approximate solution in terms of an entropy satisfying Multiresolution Analysis (MRA) is defined. Finally, a proof of convergence of the approximate solution of conservation laws using the characterization provided by the basis functions in the MRA will be given.
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Armstrong, Nicholas. "Application of the maximum entropy method to x-ray profile analysis /." Electronic version, 1999. http://adt.lib.uts.edu.au/public/adt-NTSM20031204.135221/index.html.
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Okafor, Anthony. "Entropy based techniques with applications in data mining." [Gainesville, Fla.] : University of Florida, 2005. http://purl.fcla.edu/fcla/etd/UFE0013113.
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Sevil, Hakkı Erhan Özdemir Semahat. "On the predictabiliyt of time series by metric entropy/." [s.l.]: [s.n.], 2006. http://library.iyte.edu.tr/tezler/master/makinamuh/T000543.pdf.
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Thesis (Master)--İzmir Institute of Technology, İzmir, 2006.Keywords: Time series analysis, Nonlinear analysis, condition monitoring, fault prognosis, machine health. Includes bibliographical references (leaves 48-49).
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Scafetta, Nicola. "An entropic approach to the analysis of time series." Thesis, University of North Texas, 2001. https://digital.library.unt.edu/ark:/67531/metadc3033/.
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Statistical analysis of time series. With compelling arguments we show that the Diffusion Entropy Analysis (DEA) is the only method of the literature of the Science of Complexity that correctly determines the scaling hidden within a time series reflecting a Complex Process. The time series is thought of as a source of fluctuations, and the DEA is based on the Shannon entropy of the diffusion process generated by these fluctuations. All traditional methods of scaling analysis, instead, are based on the variance of this diffusion process. The variance methods detect the real scaling only if the Gaussian assumption holds true. We call H the scaling exponent detected by the variance methods and d the real scaling exponent. If the time series is characterized by Fractional Brownian Motion, we have H¹d and the scaling can be safely determined, in this case, by using the variance methods. If, on the contrary, the time series is characterized, for example, by Lévy statistics, H ¹ d and the variance methods cannot be used to detect the true scaling. Lévy walk yields the relation d=1/(3-2H). In the case of Lévy flights, the variance diverges and the exponent H cannot be determined, whereas the scaling d exists and can be established by using the DEA. Therefore, only the joint use of two different scaling analysis methods, the variance scaling analysis and the DEA, can assess the real nature, Gauss or Lévy or something else, of a time series. Moreover, the DEA determines the information content, under the form of Shannon entropy, or of any other convenient entopic indicator, at each time step of the process that, given a sufficiently large number of data, is expected to become diffusion with scaling. This makes it possible to study the regime of transition from dynamics to thermodynamics, non-stationary regimes, and the saturation regime as well. First of all, the efficiency of the DEA is proved with theoretical arguments and with numerical work on artificial sequences. Then we apply the DEA to three different sets of real data, Genome sequences, hard x-ray solar flare waiting times and sequences of sociological interest. In all these cases the DEA makes new properties, overlooked by the standard method of analysis, emerge.
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Ndaba, Cynthia Reitumetse. "Entropy analysis in a channel flow with temperature dependent viscosity." Thesis, University of Limpopo (Turfloop Campus), 2007. http://hdl.handle.net/10386/956.
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Thesis (M.Sc. (Applied Mathematics)) --University of Limpopo, 2007The thermodynamic irreversibility in any fluid flow process can be quantified through entropy analysis. The first law of thermodynamics is simply an expression of the conservation of energy principle. The second law of thermodynamics states that all real processes are irreversible. Entropy generation is a measure of the account of irreversibility associated with the real processes. As entropy generation takes place, the quality of energy (i.e. exergy) decreases. In order to preserve the quality of energy in a fluid flow process or at least to reduce the entropy generation, it is important to study the distribution of the entropy generation within the fluid volume. In this dissertation, the inherent irreversibility in the flow of a variable viscosity fluid in both a closed channel and an open channel is investigated. The channel is assumed to be narrow, so that the lubrication approximation may be applied and the fluid viscosity is assumed to vary linearly with temperature. Both the lower and the upper surfaces of the channel are maintained at different temperature. The simplified form of governing equations is obtained and solved analytically using a perturbation technique. Expressions for fluid velocity and temperature are derived which essentially expedite to obtain expressions for volumetric entropy generation numbers, irreversibility distribution ratio and the Bejan number in the flow field. In chapter 1, a historic background of the study is highlighted. Both closed and open channels problem are investigated in chapters 2 and 3. In chapter 4, generally discussion on the overall results obtained from the investigation is displayed together with possible areas of future research work.
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Kaffashi, Farhad. "Variability analysis & its applications to physiological time series data." online version, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=case1181072302.
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Zvolinschi, Anita. "On exergy analysis and entropy production minimisation in industrial ecology." Doctoral thesis, Norwegian University of Science and Technology, Department of Chemistry, 2006. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-1591.
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The objective of this thesis is to improve the basis for applying industrial ecology to the evaluation of material and energy resource use and transformation in industrial systems. The underlying hypothesis was that when the second law of thermodynamics is applied it improves the basis for using industrial ecology for the evaluation of the use and transformation of resources in industrial systems. Exergy analysis and entropy production calculation and minimisation of industrial processes are used as methods for analysis.
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El-Ladan, Sulaim. "Human entropy (HENT) - a new approach to human reliability analysis." Thesis, University of Strathclyde, 2013. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=18990.
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Kirsch, Matthew Robert. "Signal Processing Algorithms for Analysis of Categorical and Numerical Time Series: Application to Sleep Study Data." Case Western Reserve University School of Graduate Studies / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=case1278606480.
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Zhang, Zheng. "A study of sample entropy towards process capability." Thesis, Kansas State University, 2015. http://hdl.handle.net/2097/20480.
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Master of ScienceIndustrial & Manufacturing Systems Engineering
Shing I. Chang
The process capability is a measurable property of a process related to the specification of a product. Traditionally, process capability analysis (PCA) measurements are expressed by a process capability ratio (PCR). When using a typical PCR to measure process capability, there are certain assumptions, and critics have been made towards PCR, that some the assumptions are violated. Much research has been conducted to ratify the situations when some of the assumptions are violated. This thesis, is going to demonstrate a research towards process capability using Sample Entropy method. The desirable outcome would be that this method can avoid violating the assumptions.
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Failla, Roberto. "Random growth of interfaces: Statistical analysis of single columns and detection of critical events." Thesis, University of North Texas, 2004. https://digital.library.unt.edu/ark:/67531/metadc4550/.
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The dynamics of growth and formation of surfaces and interfaces is becoming very important for the understanding of the origin and the behavior of a wide range of natural and industrial dynamical processes. The first part of the paper is focused on the interesting field of the random growth of surfaces and interfaces, which finds application in physics, geology, biology, economics, and engineering among others. In this part it is studied the random growth of surfaces from within the perspective of a single column, namely, the fluctuation of the column height around the mean value, which is depicted as being subordinated to a standard fluctuation-dissipation process with friction g. It is argued that the main properties of Kardar-Parisi-Zhang theory are derived by identifying the distribution of return times to y(0) = 0, which is a truncated inverse power law, with the distribution of subordination times. The agreement of the theoretical prediction with the numerical treatment of the model of ballistic deposition is remarkably good, in spite of the finite size effects affecting this model. The second part of the paper deals with the efficiency of the diffusion entropy analysis (DEA) when applied to the studies of stromatolites. In this case it is shown that this tool can be confidently used for the detection of complexity. The connection between the two studies is established by the use of the DEA itself. In fact, in both analyses, that is, the random growth of interfaces and the study of stromatolites, the method of diffusion entropy is able to detect the real scaling of the system, namely, the scaling of the process is determined by genuinely random events, also called critical events.
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Rybokas, Mindaugas. "The information analysis and the research on entropy for measurement data." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2006. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2006~D_20060928_151951-20485.
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Information entropy parameter has been applied for an expression of the result of data assessment and it is supplemented by an index of sample of data that was evaluated out of set of information. A modelling system and software have been developed that can be used and are used for practical processing of measurement data for circular raster scales.Duomenų įverčiui išreikšti pritaikytas informacinės entropijos parametras pateiktoje rezultato išraiškoje yra papildytas rodikliu apie duomenų imtį, kuri buvo įvertinta iš visos šį objektą charakterizuojančių duomenų aibės. Sukurta modeliavimo sistema ir programinė įranga gali būti naudojama didelio skaičiaus nežinomųjų lygtims spręsti, o praktikoje naudojama rastrinių skalių matavimo duomenims apdoroti.
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Samiei, Kasra. "Entropy analysis as a tool for optimal sustainable use of biorefineries." Thesis, Högskolan i Borås, Institutionen Ingenjörshögskolan, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-18679.
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The biorefinery concept is attractive. Increasing international concerns over issuessuch as climate change have led to political as well as social pressures for a shift fromfossil fuels to renewable resources and biomass is one abundant renewable resource.Biomass has the potential of supplying many of the fuels and chemicals which arecurrently dependent on petroleum. Much development is still needed in the field ofbiorefineries and a systematic approach to evaluate and compare process technologiesand to suggest optimizations seems necessary.The objective of this thesis is to develop entropy analysis as a possible evaluation toolfor optimization of biorefinery processes. This is a new application of entropyanalysis which is rarely discussed in the literature. The scientific basis of the entropyanalysis is described and the proposed methodology is explained. The position ofentropy analysis among other system analysis tools such as exergy analysis and lifecycle assessment is discussed along with entropy analysis earlier applications.A case study is introduced which is the IBUS (Integrated Biomass Utilization System)project in Denmark. The idea in IBUS is to integrate the biomass plant with a powerplant to utilize the surplus steam from the power plant for the internal use of thebiorefinery. The suggested method of entropy analysis is applied to this case study tocompare different processes for production of ethanol along with solid biofuel andanimal feed from Danish wheat straw. The evaluation is a gate to gate analysis inwhich production of energy carriers are also included in addition to biorefining ofwheat straw. A parallel life cycle assessment study with equivalent system boundariesis also carried out to compare the results with a conventional environmental systemsanalysis method.The results from the entropy analysis of the IBUS case study show that fermentationof C5 and C6 sugars by yeast is the most efficient process thermodynamically whilefermentation of only C6 sugars by yeast is the least efficient among the three casesstudied. Integration of the biorefinery with a coal fired CHP plant is identified as awise choice by the results of the entropy analysis method.For the IBUS process alternatives investigated in this study, the entropy results andthe LCA results (aggregated environmental load) are in correlation; entropy results areconsistent with weighting results based on two different weighting methods namelyEco indicator 99 and EPS 2000. Entropy generation is also in correlation withproduction cost for the processes analyzed in this evaluation. Another observation isthat cooling in the biorefining process contributes highly in the generation of entropy.This potential improvement option is not surfaced by the LCA conducted.The potential for further investigation and development of the tool is recognizedreflecting on some interesting observations in the results. Improvement of the tool ishighly possible for example by supplementing other implications of entropy inprocess design such as "waste potential entropy" concept which is developed as aneco-toxicity measure.Uppsatsnivå: D
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Eegunjobi, Adetatayo Samuel. "Analysis laminar flow, thermal stability, and entropy generation in porous channel." Thesis, Cape Peninsula University of Technology, 2013. http://hdl.handle.net/20.500.11838/1303.
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Thesis submitted in fulfillment of the requirements for the degree
Doctor of Technology: Mechanical Engineering
Cape Peninsula University of Technology, 2013Fluid flow through a porous channel and cylindrical pipe walls are important area of research due to its wide applications in transpiration cooling, gaseous diffusion technology, cooling of rocket, mechanized irrigation and filtration processes. It is therefore necessary to examine the effect of Navier slip, combined effects of buoyancy forces and variable viscosity on the entire flow structure. Analyzing the magneto- hydrodynamics (MHD) of unsteady flow with buoyancy effect and also investigate numerically the entropy generation in an unsteady flow through porous pipe. We have also examined the thermal stability and entropy generation in the system. The problems were investigated theoretically using appropriate mathematical models for both transient and steady state scenario. Both analytical techniques and numerical methods are employed to tackle the model nonlinear equations derived from the law of conservation of mass, momentum and energy balance. Some definitions of terms to come across and introduction to fluid flow are given in chapter 1, together with literature reviews, statement of problem and objectives of the study. Chapter 2 lays the foundation for basic fundamental equations governing fluid flow. In chapter 3, the combined effect of suction/injection and asymmetric Navier slip on the entropy generation rate for steady flow of an incompressible viscous fluid through a porous channel subjected to different temperature at the walls are investigated. Chapter 4 analyze combined effects of buoyancy forces together with Navier slip on the entropy generation in a vertical porous channel wall with suction/injection wall. Analysis of MHD unsteady flow through a porous pipe with buoyancy effects are carried out in chapter 5, while chapter 6 investigates numerically entropy generation of unsteady flow through a porous pipe with suction and chapter 7 gives concluding remarks.
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Chatterjee, Shiladitya. "Applications of Pattern Recognition Entropy (PRE) and Informatics to Data Analysis." BYU ScholarsArchive, 2019. https://scholarsarchive.byu.edu/etd/8826.
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The primary focus of my work is the application of informatics methods to the fields of materials science and analytical chemistry. The statistical analysis of data has become increasingly important in understanding the properties of materials and analytes. Statistical methods like principal component analysis (PCA) and multivariate curve resolution (MCR) are widely used for analysis in chemistry and other fields given their ability to categorize spectra in an unsupervised way. PCA is relatively easy to apply and has appealing mathematical properties. However, the results can be challenging to interpret, even for experienced users. In contrast, MCR results can be more interpretable, because the factors resemble real spectra and do not have negative scores or loadings. Nevertheless, the useful orthogonality properties of the scores and loadings in PCA are sacrificed in doing so. Other statistical analysis methods like cluster analysis and partial least squares regression (PLS-R) present their own challenges. Pattern recognition entropy (PRE) is a novel application of Shannon’s information theory for understanding the underlying complexity in spectra. Unlike PCA and MCR, PRE is a summary statistic that adopts the mathematical quantification of information and applies it for chemometric analysis. PRE values reflect the shape and complexity of spectra. Chapter 1 contains a description of the analytical methods/instruments that provided the data I analyzed by PRE and other informatics tools, including (i) X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) and (ii) liquid chromatography-mass spectrometry (LC-MS) and capillary electrophoresis (CE), (iii) a discussion of some of the commonly used statistical analysis tools like PCA, MCR, cluster analysis and PLS-R, and (iv) a description of PRE. Chapter 2 describes in much greater detail the theory associated with the statistical tools I used and PRE. Chapter 3 describes the PRE and informatics analysis of depth profiles through thin films by XPS and ToF-SIMS. Chapter 4 introduces the concept of the ‘reordered spectrum’ as an intuitive, visual representation of spectra to address the abstraction associated with PRE result. Total ion current chromatograms (TICCs) generated using LC-MS are often extremely complex and ‘noisy’. Chapter 5 describes the application of PRE as a variable reduction method for producing higher quality TICCs. Chapter 6 discusses the limitations associated with the application of PRE to TICCs and presents a new method using cross-correlation (CC) in conjunction with a PRE analysis. Chapter 7 discusses a new methodology that uses CE and PRE to detect autologous blood doping (ABD). Chapter 8 presents my conclusions of this present work and discusses the scope of future work on PRE. The thesis also contains several appendices. Appendix 1 introduces polyallylamine (PAAm) as a simple, easy-to-apply adhesion promoter for the widely used photoresist SU-8. Appendices 2, 3 and 4 contain articles I wrote that relate to trends in modern XPS instrumentation and 5-8 contain supplemental information relating to Chapters 3, 4, 5, and 7 respectively.
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Amano, Kenichi. "Roles of Water Entropy in Functioning of ATP-Driven Proteins:Theoretical Analysis." Kyoto University, 2011. http://hdl.handle.net/2433/151906.
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Jessop, Alan Thomas. "Multiattribute models for engineering evaluation." Thesis, Heriot-Watt University, 1999. http://hdl.handle.net/10399/1226.
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Joret, Gwenaël. "Entropy and stability in graphs." Doctoral thesis, Universite Libre de Bruxelles, 2007. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210605.
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Un stable (ou ensemble indépendant) est un ensemble de sommets qui sont deux à deux non adjacents. De nombreux résultats classiques en optimisation combinatoire portent sur le nombre de stabilité (défini comme la plus grande taille d'un stable), et les stables se classent certainement parmi les structures les plus simples et fondamentales en théorie des graphes.La thèse est divisée en deux parties, toutes deux liées à la notion de stables dans un graphe. Dans la première partie, nous étudions un problème de coloration de graphes, c'est à dire de partition en stables, où le but est de minimiser l'entropie de la partition. C'est une variante du problème classique de minimiser le nombre de couleurs utilisées. Nous considérons aussi une généralisation du problème aux couvertures d'ensembles. Ces deux problèmes sont appelés respectivement minimum entropy coloring et minimum entropy set cover, et sont motivés par diverses applications en théorie de l'information et en bioinformatique. Nous obtenons entre autres une caractérisation précise de la complexité de minimum entropy set cover :le problème peut être approximé à une constante lg e (environ 1.44) près, et il est NP-difficile de faire strictement mieux. Des résultats analogues sont prouvés concernant la complexité de minimum entropy coloring.
Dans la deuxième partie de la thèse, nous considérons les graphes dont le nombre de stabilité augmente dès qu'une arête est enlevée. Ces graphes sont dit être "alpha-critiques", et jouent un rôle important dans de nombreux domaines, comme la théorie extrémale des graphes ou la combinatoire polyédrique. Nous revisitons d'une part la théorie des graphes alpha-critiques, donnant à cette occasion de nouvelles démonstrations plus simples pour certains théorèmes centraux. D'autre part, nous étudions certaines facettes du polytope des ordres totaux qui peuvent être vues comme une généralisation de la notion de graphe alpha-critique. Nous étendons de nombreux résultats de la théorie des graphes alpha-critiques à cette famille de facettes.
Doctorat en Sciences
info:eu-repo/semantics/nonPublished
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Winter, Tyler Forrest. "Analysis of access-to-space missions utilizing on-board energy management and entropic analysis." Diss., Rolla, Mo. : Missouri University of Science and Technology, 2008. http://scholarsmine.mst.edu/thesis/pdf/Winter_09007dcc804d07b4.pdf.
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Thesis (M.S.)--Missouri University of Science and Technology, 2008.Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed April 18, 2008) Includes bibliographical references (p. 127-129).
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Azami, Hamed. "Entropy-based nonlinear analysis for electrophysiological recordings of brain activity in Alzheimer's disease." Thesis, University of Edinburgh, 2018. http://hdl.handle.net/1842/31106.
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Alzheimer’s disease (AD) is a neurodegenerative disorder in which the death of brain cells causes memory loss and cognitive decline. As AD progresses, changes in the electrophysiological brain activity take place. Such changes can be recorded by the electroencephalography (EEG) and magnetoencephalography (MEG) techniques. These are the only two neurophysiologic approaches able to directly measure the activity of the brain cortex. Since EEGs and MEGs are considered as the outputs of a nonlinear system (i.e., brain), there has been an interest in nonlinear methods for the analysis of EEGs and MEGs. One of the most powerful nonlinear metrics used to assess the dynamical characteristics of signals is that of entropy. The aim of this thesis is to develop entropy-based approaches for characterization of EEGs and MEGs paying close attention to AD. Recent developments in the field of entropy for the characterization of physiological signals have tried: 1) to improve the stability and reliability of entropy-based results for short and long signals; and 2) to extend the univariate entropy methods to their multivariate cases to be able to reveal the patterns across channels. To enhance the stability of entropy-based values for short univariate signals, refined composite multiscale fuzzy entropy (MFE - RCMFE) is developed. To decrease the running time and increase the stability of the existing multivariate MFE (mvMFE) while keeping its benefits, the refined composite mvMFE (RCmvMFE) with a new fuzzy membership function is developed here as well. In spite of the interesting results obtained by these improvements, fuzzy entropy (FuzEn), RCMFE, and RCmvMFE may still lead to unreliable results for short signals and are not fast enough for real-time applications. To address these shortcomings, dispersion entropy (DispEn) and frequency-based DispEn (FDispEn), which are based on our introduced dispersion patterns and the Shannon’s definition of entropy, are developed. The computational cost of DispEn and FDispEn is O(N) – where N is the signal length –, compared with the O(N2) for popular sample entropy (SampEn) and FuzEn. DispEn and FDispEn also overcome the problem of equal values for embedded vectors and discarding some information with regard to the signal amplitudes encountered in permutation entropy (PerEn). Moreover, unlike PerEn, DispEn and FDispEn are relatively insensitive to noise. As extensions of our developed DispEn, multiscale DispEn (MDE) and multivariate MDE (mvMDE) are introduced to quantify the complexity of univariate and multivariate signals, respectively. MDE and mvMDE have the following advantages over the existing univariate and multivariate multiscale methods: 1) they are noticeably faster; 2) MDE and mvMDE result in smaller coefficient of variations for synthetic and real signals showing more stable profiles; 3) they better distinguish various states of biomedical signals; 4) MDE and mvMDE do not result in undefined values for short time series; and 5) mvMDE, compared with multivariate multiscale SampEn (mvMSE) and mvMFE, needs to store a considerably smaller number of elements. In this Thesis, two restating-state electrophysiological datasets related to AD are analyzed: 1) 148-channel MEGs recorded from 62 subjects (36 AD patients vs. 26 age-matched controls); and 2) 16-channel EEGs recorded from 22 subjects (11 AD patients vs. 11 age-matched controls). The results obtained by MDE and mvMDE suggest that the controls’ signals are more and less complex at respectively short (scales between 1 to 4) and longer (scales between 5 to 12) scale factors than AD patients’ recordings for both the EEG and MEG datasets. The p-values based on Mann-Whitney U-test for AD patients vs. controls show that the MDE and mvMDE, compared with the existing complexity techniques, significantly discriminate the controls from subjects with AD at a larger number of scale factors for both the EEG and MEG datasets. Moreover, the smallest p-values are achieved by MDE (e.g., 0.0010 and 0.0181 for respectively MDE and MFE using EEG dataset) and mvMDE (e.g., 0.0086 and 0.2372 for respectively mvMDE and mvMFE using EEG dataset) for both the EEG and MEG datasets, illustrating the superiority of these developed entropy-based techniques over the state-of-the-art univariate and multivariate entropy approaches. Overall, the introduced FDispEn, DispEn, MDE, and mvMDE methods are expected to be useful for the analysis of physiological signals due to their ability to distinguish different types of time series with a low computation time.
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XAVIER, JÚNIOR Sílvio Fernando Alves. "Study of trend analysis and sample entropy of precipitation in Paraíba, Brazil." Universidade Federal Rural de Pernambuco, 2016. http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/4505.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
No presente trabalho duas metodologias diferentes foram investigadas a fim de obter uma melhor compreensão dos fenômenos de chuva e suas consequências sobre uma região particular que sofre escassez de recursos hídricos. Em primeiro lugar, foram selecionados modelos de semivariogramas para determinar as tendências de precipitação mensal no Estado da Paraíba usando krigagem ordinária. A metodologia envolve a aplicação de interpolação geoestatística de registros de precipitação de 51 anos de 69 estações pluviométricas em todo o Estado. As análises de semivariogramas mostraram que a ocorrência da anisotropia durante meses específicos teve uma forte dependência espacial (Índice de Dependência Espacial - IDE < 25 %). As tendências foram submetidas aos seguintes modelos: Gaussian, rational quadratic, circular, esférico, pentaspherical, exponencial, KBessel e tetraspherical. Os modelos com o melhor ajuste foram selecionados pela validação cruzada e Índice de Comparação de Erros (ICE). Cada conjunto de dados apresentou uma estrutura de dependência espacial particular, o que tornou necessário definir modelos específicos de semivariogramas, a fim de melhorar o ajuste do semivariograma experimental. Além disso, o mapa de previsão de erro padronizado e Hot Spots foram obtidos com o objetivo de justificar os modelos escolhidos. Um sistema climático é um sistema nãolinear bastante complexo. Para descrever as características de complexidade das séries de precipitação na Paraíba, propomos o uso do Sample Entropy, um algoritmo baseado na entropia de Shannon, para medir a complexidade da série de precipitação. Quatro macro-regiões da Paraíba foram analisadas: Mata, Agreste, Borborema e Sertão. Os resultados das análises mostraram que as complexidades de precipitação mensal média têm diferenças nas macro-regiões. Sample Entropy pode refletir a mudança dinâmica da série de precipitação proporcionando uma nova maneira de investigar a complexidade das séries hidrológicas. A complexidade apresenta uma variação regional do sistema de recursos hídricos locais que podem influenciar a base para a utilização e desenvolvimento de recursos em áreas secas.
The objective of this work was to present two different methodologies in order to obtain a better comprehension of rainfall phenomena and its consequences over a particular region which suffers from water scarcity. Firstly, semivariogram models were selected to estimate trends in monthly precipitation in Paraíba State-Brazil using ordinary kriging. The methodology involves the application of geostatistical interpolation of precipitation records of 51 years from 69 rainfall stations across the state. Analysis of semivariograms showed that anisotropy for specific months had a strong spatial dependence (Index of Spatial Dependence - IDE <25%). The trends were subjected to the following models: circular, spherical, pentaspherical, exponential, Gaussian, rational quadratic, K-Bessel and tetraspherical. The models with the best fit were selected by cross-validation and Error Comparison Index (ECI). Each data set month had a particular spatial dependence structure, which made it necessary to define specific models of semivariograms in order to enhance the adjustment of the experimental semivariogram. Besides, the standardized error prediction map and hot spot analysis were obtained with the aim of justifying the chosen models. Furthermore, one can see that a climate system is a complex nonlinear system. To describe the complexity characteristics of precipitation series in Paraíba, we propose the use of sample entropy, a kind of entropy-based algorithm, to measure the complexity of precipitation series. The Paraíba’s four macro-regions: Mata, Agreste, Borborema, and Sertão were analyzed. Results of analysis show that complexities of monthly average precipitation have differences in the macro-regions. Sample entropy can reflect the dynamic change of precipitation series providing a new way to investigate the complexity of hydrological series. The complexity exhibits an areal variation of local water resources system which can influence the basis for utilizing and developing resources in dry areas.
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Bhattacharjee, Abhishek. "Measuring Influence Across Social Media Platforms: Empirical Analysis Using Symbolic Transfer Entropy." Scholar Commons, 2019. https://scholarcommons.usf.edu/etd/7745.
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Social media platforms are interconnected environments that influence each other. Information from one social media platform spreads to another. This thesis proposes a platform-independent framework to analyze information transfer across social media platforms. This thesis uses Symbolic Transfer Entropy and Statistical Significance Test to measure influence and optimize the time window of influence between different platforms. To validate the framework, the thesis analyses the temporal activity dynamics and the information transfer across three different platforms, Reddit, Twitter and GitHub.
Two data driven studies are described in this thesis. The first study finds the optimum time windows of influence between the three platforms during two different cyber attack events on cryptocurrency exchanges. It finds that specific types of activities are more influential than others, and optimum time interval changes with pre, during, and post event days. The second study applies information revealed in the first study and specifically the optimal time window to link cross-platform information cascades from Twitter and Reddit. The case-study is a heuristic that, we show, can reduce the search space for connecting information cascades across different platforms.
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Assirati, Lucas. "Entropia aplicada ao reconhecimento de padrões em imagens." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/76/76132/tde-24092014-104641/.
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Este trabalho faz um estudo do uso da entropia como ferramenta para o reconhecimento de padrões em imagens. A entropia é um conceito utilizado em termodinâmica para medir o grau de organização de um meio. Entretanto, este conceito pode ser ampliado para outras áreas do conhecimento. A adoção do conceito em Teoria da Informação e, por consequência, em reconhecimento de padrões foi introduzida por Shannon no trabalho intitulado \"A Mathematical Theory of Communication\", publicado no ano de 1948. Neste mestrado, além da entropia clássica de Boltzman-Gibbs-Shannon, são investigadas a entropia generalizada de Tsallis e suas variantes (análise multi-escala, múltiplo índice q e seleção de atributos), aplicadas ao reconhecimento de padrões em imagens. Utilizando bases de dados bem conhecidas na literatura, realizou-se estudos comparativos entre as técnicas. Os resultados mostram que a entropia de Tsallis, através de análise multi-escala e múltiplo índice q, tem grande vantagem sobre a entropia de Boltzman-Gibbs-Shannon. Aplicações práticas deste estudo são propostas com o intuito de demonstrar o potencial do método.This work studies the use of entropy as a tool for pattern recognition in images. Entropy is a concept used in thermodynamics to measure the degree of organization of a system. However, this concept can be extended to other areas of knowledge. The adoption of the concept in information theory and, consequently, in pattern recognition was introduced by Shannon in the paper entitled \"A Mathematical Theory of Communication\", published in 1948. In this master thesis, the classical Boltzmann-Gibbs-Shannon entropy, the generalized Tsallis entropy and its variants (multi-scale analysis, multiple q index, and feature selection) are studied, applied to pattern recognition in images. Using well known databases, we performed comparative studies between the techniques. The results show that the Tsallis entropy, through multiscale analysis and multiple q index has a great advantage over the classical Boltzmann-Gibbs- Shannon entropy. Practical applications of this study are proposed in order to demonstrate the potential of the method.
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Dourado, Jonas Rossi. "Delayed Transfer Entropy applied to Big Data." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/18/18153/tde-19022019-134228/.
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Recent popularization of technologies such as Smartphones, Wearables, Internet of Things, Social Networks and Video streaming increased data creation. Dealing with extensive data sets led the creation of term big data, often defined as when data volume, acquisition rate or representation demands nontraditional approaches to data analysis or requires horizontal scaling for data processing. Analysis is the most important Big Data phase, where it has the objective of extracting meaningful and often hidden information. One example of Big Data hidden information is causality, which can be inferred with Delayed Transfer Entropy (DTE). Despite DTE wide applicability, it has a high demanding processing power which is aggravated with large datasets as those found in big data. This research optimized DTE performance and modified existing code to enable DTE execution on a computer cluster. With big data trend in sight, this results may enable bigger datasets analysis or better statistical evidence.A recente popularização de tecnologias como Smartphones, Wearables, Internet das Coisas, Redes Sociais e streaming de Video aumentou a criação de dados. A manipulação de grande quantidade de dados levou a criação do termo Big Data, muitas vezes definido como quando o volume, a taxa de aquisição ou a representação dos dados demanda abordagens não tradicionais para analisar ou requer uma escala horizontal para o processamento de dados. A análise é a etapa de Big Data mais importante, tendo como objetivo extrair informações relevantes e às vezes escondidas. Um exemplo de informação escondida é a causalidade, que pode ser inferida utilizando Delayed Transfer Entropy (DTE). Apesar do DTE ter uma grande aplicabilidade, ele possui uma grande demanda computacional, esta última, é agravada devido a grandes bases de dados como as encontradas em Big Data. Essa pesquisa otimizou e modificou o código existente para permitir a execução de DTE em um cluster de computadores. Com a tendência de Big Data em vista, esse resultado pode permitir bancos de dados maiores ou melhores evidências estatísticas.
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Hagemann, Johannes Franz. "Computer aided process design : the design of a distillation train and its control system." Thesis, University of South Wales, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.284891.
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Galletti, Michele. "Fully Polarimetric Analysis of Weather Radar Signatures." Doctoral thesis, Universitätsbibliothek Chemnitz, 2010. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-201000174.
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Diese (Doktor)arbeit beschäftigt sich mit Radar-Polarimetrie, insbesondere mit der Untersuchung der Eigenschaften von polarimetrischen Variablen, die potenziellen Nutzen für die Radar-Meteorologie haben. Für den Einsatz in Dual-Polarisations-Radargeräten wird der Polarisationsgrad analysiert. Diese Variable wird in künftigen operationellen Radargeräten verfügbar sein. Der Polarisationsgrad hängt vom transmittierten Polarisationszustand und in weiterer Folge auch vom Betriebsmodus des Radargeräts ab. Der Hauptbetriebsmodus von operationellen Radargeräten sendet und empfängt gleichzeitig sowohl die horizontale als auch die vertikale Komponente. Der sekundäre Betriebsmodus sendet und empfängt simultan die horizontal polarisierte Komponente. In dieser Arbeit werden beide Polarisationsgrade untersucht. Da operationelle Systeme derzeit auf den Dual-Polarisationsmodus aufgerüstet werden, sollte künftig die Anwendungsmöglichkeiten von vollpolarimetrischen Wetterradarsystemen untersucht werden. Aus allen Variablen, die in diesem Betriebsmodus zur Verfügung stehen, wurde die Entropie (des gemessen Objektes) ausgewählt und wegen seiner engen Beziehung zum Polarisationsgrad näher untersuchtThe present doctoral thesis deals with radar polarimetry, namely with the investigation of properties of polarimetric variables potentially useful in radar meteorology. For use with dual-polarization radars, the degree of polarization is analyzed. This variable is available to planned operational radars. The degree of polarization is dependent on transmit polarization state and, consequently, it is dependent on the radar system operating mode. The primary operating mode of operational radars consists in simultaneous transmission and simultaneous receive of both horizontal and vertical components. The secondary operating mode consists of horizontal transmission and simultaneous receive. Both degrees of polarization are investigated in this thesis. Also, as operational systems are being updated to dual-polarization, research should start investigating the capabilities of fully polarimetric weather radar systems. Among the numerous variables available from this operating mode, the target entropy was chosen for investigation, also because of its close relation to the degree of polarization
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Li, Chang. "Complexity Analysis of Physiological Time Series with Applications to Neonatal Sleep Electroencephalogram Signals." Case Western Reserve University School of Graduate Studies / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=case1345657829.
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Ames, Allison Jennifer. "Monte Carlo Experiments on Maximum entropy Constructive Ensembles for Time Series Analysis and Inference." Thesis, Virginia Tech, 2005. http://hdl.handle.net/10919/32571.
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In econometric analysis, the traditional bootstrap and related methods often require the assumption of stationarity. This assumption says that the distribution function of the process remains unchanged when shifted in time by an arbitrary value, imposing perfect time-homogeneity. In terms of the joint distribution, stationarity implies that the date of the first time index is not relevant. There are many problems with this assumption however for time series data. With time series, the order in which random realizations occur is crucial. This is why theorists work with stochastic processes, with two implicit arguments, w and t, where w represents the sample space and t represents the order. The question becomes, is there a bootstrap procedure that can preserve the ordering without assuming stationarity? The new method for maximum entropy ensembles proposed by Dr. H. D. Vinod might satisfy the Ergodic and Kolmogorov theorems, without assuming stationarity.Master of Science
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Herfert, Matthias [Verfasser]. "Nonparametric Inference of Utilites : Entropy Analysis with Applications to Consumer Theory / Matthias Herfert." Hamburg : Diplom.de, 2006. http://d-nb.info/1185646434/34.
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Padayachee, Jayanethie. "The application of Bayesian statistics and maximum entropy to Ion beam analysis techniques." Master's thesis, University of Cape Town, 1997. http://hdl.handle.net/11427/16143.
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Bibliography: pages 128-129.The elimination of some blurring property, such as the detector response function, from spectra has received a considerable amount of attention. The problem is usually complicated by the presence of noise in the data, and in general, there exists an infinite set of possible solutions which are consistent with the data within the bounds imposed by the noise. Such a problem is known, generally, as an ill-defined inverse problem. Many techniques have been developed in an attempt to solve inverse problems, for example the problem of deconvolution, but these techniques employ ad hoc modifications to solve different problems. Bayesian Statistics has been proved to be the only consistent method for solving inverse problems of the type where the information is expressed in terms of probability distributions. This dissertation presents results of applying the Bayesian formalism, together with the concepts of maximum information entropy and multiresolution pixons, to various inverse problems in ion beam analysis; The results of this method of deconvoluting Rutherford Backscattering Spectrometry (RBS) and Proton Induced X-ray Emission (PIXE) spectra are compared to the results from other deconvolution techniques, namely Fourier Transforms, Jansson's method and maximum entropy (MaxEnt) without pixons. All the deconvolution techniques show an improvement in the resolution of the RBS spectra but only the MaxEnt techniques show a significant improvement in the resolution of the PIXE spectra. The MaxEnt methods also produce physically acceptable results. The MaxEnt formalism was applied to the extraction of depth profiles from RBS and PIXE spectra and yielded good results. The technique was also used to deconvolute the beam profile from one-dimensional nuclear microprobe scans.
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Weissmann, Gerhard. "An entropy field controls economics and the environment : the application of the concept of increase in entropy (based on an inferred entropy field) to the analysis of human economic behaviour and its environmental impact /." Title page, table of contents and abstract only, 1992. http://web4.library.adelaide.edu.au/theses/09ENV/09envw433.pdf.
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Raele, Ricardo. "O sistema sócio-ecológico do rio Pinheiros: um modelo conceitual baseado na Teoria de Sistemas e Stakeholders Analysis." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/91/91131/tde-13022014-082511/.
Full textAbstract:
Esta pesquisa apresenta a construção de um modelo conceitual para a sustentabilidade do Rio Pinheiros na capital de São Paulo através da aplicação de um método de mapeamento e análise de variáveis em sistemas sócio-ecológicos. O método se baseia na Teoria Geral dos Sistemas e na Stakeholder Analysis e visa identificar variáveis relevantes por meio de uma abordagem hierárquica e transdisciplinar. Nesse sentido, especialistas de diversas áreas do conhecimento foram consultados para que as variáveis fossem identificadas e, ainda, a elas se atribuíssem níveis de importância. Além disso, uma matriz de adjacência foi elaborada a fim de identificar as conexões entre as variáveis. Duas hipóteses foram testadas. A primeira - referente à distribuição não aleatória dos pontos de importância atribuídos pelos diversos especialistas - foi corroborada. A segunda - que postulava a sobreposição das variáveis mais importantes e mais conectadas em um conjunto formado pelos quartis dos valores mais altos de importância e conectância - foi refutada. A verificação da primeira hipótese foi feita com o teste não paramétrico do sinal e distribuições binomiais. A verificação da segunda hipótese se deu com o cálculo da porcentagem de maioria simples. A partir dos resultados obtidos, construiu-se o modelo conceitual da sustentabilidade do Rio Pinheiros com a ajuda de um software de modelagem de redes complexas e hierárquicas.This research presents the construction of a conceptual model for the sustainability of the Pinheiros River in São Paulo City through the application of a method of mapping and analysis of variables in socio-ecological systems. The method is based both on the General Theory of Systems and on the Stakeholder Analysis and aims at the identification of relevant variables through a hierarchical and transdisciplinary approach. In this sense, specialists from different fields of expertise were consulted in order to identify the variables and to assign them importance levels. An adjacency matrix was developed so that connections amidst the variables could be identified. Two hypotheses were tested. The first - concerning the nonfortuitous distribution of the importance points assigned by the several specialists - was corroborated. The second - which postulated the superposition of the more important and more connected variables in a group formed by the quartile of the more important variables - was refuted. The first hypothesis was verified with the support of the non-parametric signal and binomial distribution test. The second hypothesis was verified through the simple majority calculation. Based on the results and with the help of a software able to model hierarchical and complex networks, a conceptual model of sustainability for the Pinheiros River was built.
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Bagci, Gokhan Baris. "The Nonadditive Generalization of Klimontovich's S-Theorem for Open Systems and Boltzmann's Orthodes." Thesis, University of North Texas, 2008. https://digital.library.unt.edu/ark:/67531/metadc9124/.
Full textAbstract:
We show that the nonadditive open systems can be studied in a consistent manner by using a generalized version of S-theorem. This new generalized S-theorem can further be considered as an indication of self-organization in nonadditive open systems as prescribed by Haken. The nonadditive S-theorem is then illustrated by using the modified Van der Pol oscillator. Finally, Tsallis entropy as an equilibrium entropy is studied by using Boltzmann's method of orthodes. This part of dissertation shows that Tsallis ensemble is on equal footing with the microcanonical, canonical and grand canonical ensembles. However, the associated entropy turns out to be Renyi entropy.