Готові списки джерел за темами / Non-stationary distribution

Добірка наукової літератури з теми "Non-stationary distribution"

Автор: Grafiati

Опубліковано: 14 березня 2023

Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями

Оберіть тип джерела:

Зміст

Статті в журналах
Дисертації
Книги
Частини книг
Тези доповідей конференцій
Звіти організацій

Ознайомтеся зі списками актуальних статей, книг, дисертацій, тез та інших наукових джерел на тему "Non-stationary distribution".

Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.

Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.

Статті в журналах з теми "Non-stationary distribution"

Kislitsyn, Alexey Alexeevich, Antonina Borisovna Kozlova, Marina Borisovna Korsakova, Evgeniy Leonidovich Masherov, and Yurii Nikolaevich Orlov. "Stationary point of significance level for non-stationary distribution functions." Keldysh Institute Preprints, no. 113 (2018): 1–20. http://dx.doi.org/10.20948/prepr-2018-113.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

TARASOV, VASILY E. "CLASSICAL CANONICAL DISTRIBUTION FOR DISSIPATIVE SYSTEMS." Modern Physics Letters B 17, no. 23 (October 10, 2003): 1219–26. http://dx.doi.org/10.1142/s0217984903006268.

Повний текст джерела

Анотація:

We derive the canonical distribution as a stationary solution of the Liouville equation for the classical dissipative system. Dissipative classical systems can have stationary states that look like canonical Gibbs distributions. The condition for non-potential forces which leads to this stationary solution is very simple: the power of the non-potential forces must be directly proportional to the velocity of the Gibbs phase (phase entropy density) change. The example of the canonical distribution for a linear oscillator with friction is considered.

Стилі APA, Harvard, Vancouver, ISO та ін.

Hesarkazzazi, Sina, Rezgar Arabzadeh, Mohsen Hajibabaei, Wolfgang Rauch, Thomas R. Kjeldsen, Ilaria Prosdocimi, Attilio Castellarin, and Robert Sitzenfrei. "Stationary vs non-stationary modelling of flood frequency distribution across northwest England." Hydrological Sciences Journal 66, no. 4 (March 12, 2021): 729–44. http://dx.doi.org/10.1080/02626667.2021.1884685.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Foley, Robert D. "Stationary Poisson departure processes from non-stationary queues." Journal of Applied Probability 23, no. 1 (March 1986): 256–60. http://dx.doi.org/10.2307/3214138.

Повний текст джерела

Анотація:

We present some non-stationary infinite-server queueing systems with stationary Poisson departure processes. In Foley (1982), it was shown that the departure process from the Mt/Gt/∞ queue was a Poisson process, possibly non-stationary. The Mt/Gt/∞ queue is an infinite-server queue with a stationary or non-stationary Poisson arrival process and a general server in which the service time of a customer may depend upon the customer's arrival time. Mirasol (1963) pointed out that the departure process from the M/G/∞ queue is a stationary Poisson process. The question arose whether there are any other Mt/Gt/∞ queueing systems with stationary Poisson departure processes. For example, if the arrival rate is periodic, is it possible to select the service-time distribution functions to fluctuate in order to compensate for the fluctuations of the arrival rate? In this situation and in more general situations, it is possible to select the server such that the system yields a stationary Poisson departure process.

Стилі APA, Harvard, Vancouver, ISO та ін.

Foley, Robert D. "Stationary Poisson departure processes from non-stationary queues." Journal of Applied Probability 23, no. 01 (March 1986): 256–60. http://dx.doi.org/10.1017/s0021900200106497.

Повний текст джерела

Анотація:

We present some non-stationary infinite-server queueing systems with stationary Poisson departure processes. In Foley (1982), it was shown that the departure process from the Mt/Gt/∞ queue was a Poisson process, possibly non-stationary. The Mt/Gt /∞ queue is an infinite-server queue with a stationary or non-stationary Poisson arrival process and a general server in which the service time of a customer may depend upon the customer's arrival time. Mirasol (1963) pointed out that the departure process from the M/G/∞ queue is a stationary Poisson process. The question arose whether there are any other Mt/Gt/∞ queueing systems with stationary Poisson departure processes. For example, if the arrival rate is periodic, is it possible to select the service-time distribution functions to fluctuate in order to compensate for the fluctuations of the arrival rate? In this situation and in more general situations, it is possible to select the server such that the system yields a stationary Poisson departure process.

Стилі APA, Harvard, Vancouver, ISO та ін.

Behzadi, Mostafa, Mohd Bakri Adam, and Anwar Fitrianto. "Univariate Generalized Additive Models for Simulated Stationary and Non-Stationary Generalized Pareto Distribution." Journal of Mathematics and Statistics 13, no. 2 (February 1, 2017): 169–76. http://dx.doi.org/10.3844/jmssp.2017.169.176.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Park, Namuk, and Songkuk Kim. "FlexSketch: Estimation of Probability Density for Stationary and Non-Stationary Data Streams." Sensors 21, no. 4 (February 4, 2021): 1080. http://dx.doi.org/10.3390/s21041080.

Повний текст джерела

Анотація:

Efficient and accurate estimation of the probability distribution of a data stream is an important problem in many sensor systems. It is especially challenging when the data stream is non-stationary, i.e., its probability distribution changes over time. Statistical models for non-stationary data streams demand agile adaptation for concept drift while tolerating temporal fluctuations. To this end, a statistical model needs to forget old data samples and to detect concept drift swiftly. In this paper, we propose FlexSketch, an online probability density estimation algorithm for data streams. Our algorithm uses an ensemble of histograms, each of which represents a different length of data history. FlexSketch updates each histogram for a new data sample and generates probability distribution by combining the ensemble of histograms while monitoring discrepancy between recent data and existing models periodically. When it detects concept drift, a new histogram is added to the ensemble and the oldest histogram is removed. This allows us to estimate the probability density function with high update speed and high accuracy using only limited memory. Experimental results demonstrate that our algorithm shows improved speed and accuracy compared to existing methods for both stationary and non-stationary data streams.

Стилі APA, Harvard, Vancouver, ISO та ін.

Scala, Pietro, Giuseppe Cipolla, Dario Treppiedi, and Leonardo Valerio Noto. "The Use of GAMLSS Framework for a Non-Stationary Frequency Analysis of Annual Runoff Data over a Mediterranean Area." Water 14, no. 18 (September 13, 2022): 2848. http://dx.doi.org/10.3390/w14182848.

Повний текст джерела

Анотація:

Climate change affects all the components of the hydrological cycle. Starting from precipitation distribution, climate alterations have direct effects on both surface water and groundwater in terms of their quantity and quality. These effects lead to modifications in water availability for agriculture, ecology and other social uses. Change in rainfall patterns also affects the runoff of natural rivers. For this reason, studying runoff data according to classical hydrological approaches, i.e., statistical inference methods that exploit stationary probability distributions, might result in missing important information relevant to climate change. From this point of view, a new approach has to be found in the study of this type of data that allows for non-stationary analysis. In this study, the statistical framework known as Generalized Additive Models for Location, Scale and Shape (GAMLSS), which can be used to carry out non-stationary statistical analyses, was applied in a non-stationary frequency analysis of runoff data collected by four gauges widely distributed across Sicily (Italy) in the period 1916–1998. A classical stationary frequency analysis of these runoff data was followed by a different non-stationary frequency analysis; while the first was made using annual rainfall as a covariate, with the aim of understanding how certain statistical parameters of runoff distribution vary with changes in rainfall, the second derived information about the temporal variability of runoff frequencies by considering time as a covariate. A comparison between stationary and non-stationary approaches was carried out using the Akaike information criterion as a performance metric. After analyzing four different probability distributions, the non-stationary model with annual rainfall as a covariate was found to be the best among all those examined, and the three-parameter lognormal the most frequently preferred distribution.

Стилі APA, Harvard, Vancouver, ISO та ін.

Crisci, Carolina, and Gonzalo Perera. "Asymptotic Extremal Distribution for Non-Stationary, Strongly-Dependent Data." Advances in Pure Mathematics 12, no. 08 (2022): 479–89. http://dx.doi.org/10.4236/apm.2022.128036.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Ghosh, Ashish, and Heinz Muehlenbein. "Univariate marginal distribution algorithms for non-stationary optimization problems." International Journal of Knowledge-based and Intelligent Engineering Systems 8, no. 3 (January 10, 2005): 129–38. http://dx.doi.org/10.3233/kes-2004-8301.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Більше джерел

Дисертації з теми "Non-stationary distribution"

Hesarkazzazi, Sina. "Stationary vs. non-stationary modeling of flood frequency distribution across North West England (UK)." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2018.

Знайти повний текст джерела

Анотація:

As environmental change is happening at an unprecedented pace, a comprehensive and holistic approach is needed in order to mitigate the increasing negative effect of extreme natural events occurring based on the natural and anthropogenic variations. Of all the geophysical phenomena, flooding is one of the most catastrophic events, leading to quite a few losses and damages across the World. Recent extraordinary flood events happened in north – western England, precisely sequences of the severe floods in the county of Cumbria, Lancashire and Manchester in 2004, 2009 and 2015, have brought many concerns not only for the residents but also for the community of hydrologists in UK. These extreme events in these areas comparing with their typical river discharge values have raised an important question of whether any significant changes in the magnitude of river flows can be detected as a result of natural/human - induced clime change. If so, whether they can be attributed to any meteorological predictors such as rainfall frequency analysis. The results, performed for 39 river gauging stations based on annual maxima (AM) approach, indicate that around 92% of the river gauging stations show non – stationary behaviour; whereas only in 8%, stationarity is dominant. More importantly, annual rainfall is deemed as the best explanatory variable to express the variability of our data much better than other covariates for a vast majority of stations (around 60%).

Стилі APA, Harvard, Vancouver, ISO та ін.

Rajagopalan, Satish. "Detection of Rotor and Load Faults in BLDC Motors Operating Under Stationary and Non-Stationary Conditions." Diss., Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/11524.

Повний текст джерела

Анотація:

Brushless Direct Current (BLDC) motors are one of the motor types rapidly gaining popularity. BLDC motors are being increasingly used in critical high performance industries such as appliances, automotive, aerospace, consumer, medical, industrial automation equipment and instrumentation. Fault detection and condition monitoring of BLDC machines is therefore assuming a new importance. The objective of this research is to advance the field of rotor and load fault diagnosis in BLDC machines operating in a variety of operating conditions ranging from constant speed to continuous transient operation. This objective is addressed as three parts in this research. The first part experimentally characterizes the effects of rotor faults in the stator current and voltage of the BLDC motor. This helps in better understanding the behavior of rotor defects in BLDC motors. The second part develops methods to detect faults in loads coupled to BLDC motors by monitoring the stator current. As most BLDC applications involve non-stationary operating conditions, the diagnosis of rotor faults in non-stationary conditions forms the third and most important part of this research. Several signal processing techniques are reviewed to analyze non-stationary signals. Three new algorithms are proposed that can track and detect rotor faults in non-stationary or transient current signals.

Стилі APA, Harvard, Vancouver, ISO та ін.

Muševič, Sašo. "Non-stationary sinusoidal analysis." Doctoral thesis, Universitat Pompeu Fabra, 2013. http://hdl.handle.net/10803/123809.

Повний текст джерела

Анотація:

Muchos tipos de señales que encontramos a diario pertenecen a la categoría de sinusoides no estacionarias. Una gran parte de esas señales son sonidos que presentan una gran variedad de características: acústicos/electrónicos, sonidos instrumentales harmónicos/impulsivos, habla/canto, y la mezcla de todos ellos que podemos encontrar en la música. Durante décadas la comunidad científica ha estudiado y analizado ese tipo de señales. El motivo principal es la gran utilidad de los avances científicos en una gran variedad de áreas, desde aplicaciones médicas, financiera y ópticas, a procesado de radares o sonar, y también a análisis de sistemas. La estimación precisa de los parámetros de sinusoides no estacionarias es una de las tareas más comunes en procesado digital de señales, y por lo tanto un elemento fundamental e indispensable para una gran variedad de aplicaciones. Las transformaciones de tiempo y frecuencia clásicas son solamente apropiadas para señales con variación lenta de amplitud y frecuencia. Esta suposición no suele cumplirse en la práctica, lo que conlleva una degradación de calidad y la aparición de artefactos. Además, la resolución temporal y frecuencial no se puede incrementar arbitrariamente debido al conocido principio de incertidumbre de Heisenberg. \\ El principal objetivo de esta tesis es revisar y mejorar los métodos existentes para el análisis de sinusoides no estacionarias, y también proponer nuevas estrategias y aproximaciones. Esta disertación contribuye sustancialmente a los análisis sinusoidales existentes: a) realiza una evaluación crítica del estado del arte y describe con gran detalle los métodos de análisis existentes, b) aporta mejoras sustanciales a algunos de los métodos existentes más prometedores, c) propone varias aproximaciones nuevas para el análisis de los modelos sinusoidales existentes i d) propone un modelo sinusoidal muy general y flexible con un algoritmo de análisis directo y rápido.
Many types of everyday signals fall into the non-stationary sinusoids category. A large family of such signals represent audio, including acoustic/electronic, pitched/transient instrument sounds, human speech/singing voice, and a mixture of all: music. Analysis of such signals has been in the focus of the research community for decades. The main reason for such intense focus is the wide applicability of the research achievements to medical, financial and optical applications, as well as radar/sonar signal processing and system analysis. Accurate estimation of sinusoidal parameters is one of the most common digital signal processing tasks and thus represents an indispensable building block of a wide variety of applications. Classic time-frequency transformations are appropriate only for signals with slowly varying amplitude and frequency content - an assumption often violated in practice. In such cases, reduced readability and the presence of artefacts represent a significant problem. Time and frequency resolu

Стилі APA, Harvard, Vancouver, ISO та ін.

Mamikonyan, Arsen. "Variational inference for non-stationary distributions." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/113125.

Повний текст джерела

Анотація:

Thesis: M. Eng., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2017.
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (page 49).
In this thesis, I look at multiple Variational Inference algorithm, transform Kalman Variational Bayes and Stochastic Variational Inference into streaming algorithms and try to identify if any of them work with non-stationary distributions. I conclude that Kalman Variational Bayes can do as good as any other algorithm for stationary distributions, and tracks non-stationary distributions better than any other algorithm in question.
by Arsen Mamikonyan.
M. Eng.

Стилі APA, Harvard, Vancouver, ISO та ін.

Jalbert, Jonathan. "Développement d'un modèle statistique non stationnaire et régional pour les précipitations extrêmes simulées par un modèle numérique de climat." Thesis, Université Grenoble Alpes (ComUE), 2015. http://www.theses.fr/2015GREAU032/document.

Повний текст джерела

Анотація:

Les inondations constituent le risque naturel prédominant dans le monde et les dégâts qu'elles causent sont les plus importants parmi les catastrophes naturelles. Un des principaux facteurs expliquant les inondations sont les précipitations extrêmes. En raison des changements climatiques, l'occurrence et l'intensité de ces dernières risquent fort probablement de s'accroître. Par conséquent, le risque d'inondation pourrait vraisemblablement s'intensifier. Les impacts de l'évolution des précipitations extrêmes sont désormais un enjeu important pour la sécurité du public et pour la pérennité des infrastructures. Les stratégies de gestion du risque d'inondation dans le climat futur sont essentiellement basées sur les simulations provenant des modèles numériques de climat. Un modèle numérique de climat procure notamment une série chronologique des précipitations pour chacun des points de grille composant son domaine spatial de simulation. Les séries chronologiques simulées peuvent être journalières ou infra-journalières et elles s'étendent sur toute la période de simulation, typiquement entre 1961 et 2100. La continuité spatiale des processus physiques simulés induit une cohérence spatiale parmi les séries chronologiques. Autrement dit, les séries chronologiques provenant de points de grille avoisinants partagent souvent des caractéristiques semblables. De façon générale, la théorie des valeurs extrêmes est appliquée à ces séries chronologiques simulées pour estimer les quantiles correspondants à un certain niveau de risque. La plupart du temps, la variance d'estimation est considérable en raison du nombre limité de précipitations extrêmes disponibles et celle-ci peut jouer un rôle déterminant dans l'élaboration des stratégies de gestion du risque. Par conséquent, un modèle statistique permettant d'estimer de façon précise les quantiles de précipitations extrêmes simulées par un modèle numérique de climat a été développé dans cette thèse. Le modèle développé est spécialement adapté aux données générées par un modèle de climat. En particulier, il exploite l'information contenue dans les séries journalières continues pour améliorer l'estimation des quantiles non stationnaires et ce, sans effectuer d'hypothèse contraignante sur la nature de la non-stationnarité. Le modèle exploite également l'information contenue dans la cohérence spatiale des précipitations extrêmes. Celle-ci est modélisée par un modèle hiérarchique bayésien où les lois a priori des paramètres sont des processus spatiaux, en l'occurrence des champs de Markov gaussiens. L'application du modèle développé à une simulation générée par le Modèle régional canadien du climat a permis de réduire considérablement la variance d'estimation des quantiles en Amérique du Nord
Precipitation extremes plays a major role in flooding events and their occurrence as well as their intensity are expected to increase. It is therefore important to anticipate the impacts of such an increase to ensure the public safety and the infrastructure sustainability. Since climate models are the only tools for providing quantitative projections of precipitation, flood risk management for the future climate may be based on their simulations. Most of the time, the Extreme value theory is used to estimate the extreme precipitations from a climate simulation, such as the T-year return levels. The variance of the estimations are generally large notably because the sample size of the maxima series are short. Such variance could have a significant impact for flood risk management. It is therefore relevant to reduce the estimation variance of simulated return levels. For this purpose, the aim of this paper is to develop a non-stationary and regional statistical model especially suited for climate models that estimates precipitation extremes. At first, the non-stationarity is removed by a preprocessing approach. Thereafter, the spatial correlation is modeled by a Bayesian hierarchical model including an intrinsic Gaussian Markov random field. The model has been used to estimate the 100-year return levels over North America from a simulation by the Canadian Regional Climate Model. The results show a large estimation variance reduction when using the regional model

Стилі APA, Harvard, Vancouver, ISO та ін.

Hili, Ouagnina. "Contribution à l'estimation des modèles de séries temporelles non linéaires." Université Louis Pasteur (Strasbourg) (1971-2008), 1995. http://www.theses.fr/1995STR13169.

Повний текст джерела

Анотація:

Le but de la these est d'effectuer l'inference statistique d'une classe generale de modeles de series temporelles non lineaires. Notre contribution consiste d'abord a determiner des conditions assurant l'existence d'une loi stationnaire, l'existence des moments de cette loi stationnaire et la forte melangeance de tels modeles. Nous etablissons ensuite les proprietes asymptotiques de l'estimateur du minimum de distance d'hellinger du parametre d'interet. La robustesse de cet estimateur est egalement envisagee. Nous examinons aussi, via la methode des moindres carres, les proprietes asymptotiques des estimateurs des coefficients des modeles autoregressifs a seuils

Стилі APA, Harvard, Vancouver, ISO та ін.

Nguyen, Yen Thi Hong. "Time-frequency distributions : approaches for incomplete non-stationary signals." Thesis, University of Leeds, 2018. http://etheses.whiterose.ac.uk/19681/.

Повний текст джерела

Анотація:

There are many sources of waveforms or signals existing around us. They can be natural phenomena such as sound, light and invisible like electromagnetic fields, voltage, etc. Getting an insight into these waveforms helps explain the mysteries surrounding our world and the signal spectral analysis (i.e. the Fourier transform) is one of the most significant approaches to analyze a signal. Nevertheless, Fourier analysis cannot provide a time-dependent spectrum description for spectrum-varying signals-non-stationary signal. In these cases, time-frequency distribu- tions are employed instead of the traditional Fourier transform. There have been a variety of methods proposed to obtain the time-frequency representations (TFRs) such as the spectrogram or the Wigner-Ville distribution. The time-frequency distributions (TFDs), indeed, offer us a better signal interpretation in a two-dimensional time-frequency plane, which the Fourier transform fails to give. Nevertheless, in the case of incomplete data, the time-frequency displays are obscured by artifacts, and become highly noisy. Therefore, signal time-frequency features are hardly extracted, and cannot be used for further data processing. In this thesis, we propose two methods to deal with compressed observations. The first one applies compressive sensing with a novel chirp dictionary. This method assumes any windowed signal can be approximated by a sum of chirps, and then performs sparse reconstruction from windowed data in the time domain. A few improvements in computational complexity are also included. In the second method, fixed kernel as well as adaptive optimal kernels are used. This work is also based on the assumption that any windowed signal can be approximately represented by a sum of chirps. Since any chirp's auto-terms only occupy a certain area in the ambiguity domain, the kernel can be designed in a way to remove the other regions where auto-terms do not reside. In this manner, not only cross-terms but also missing samples’ artifact are mitigated significantly. The two proposed approaches bring about a better performance in the time-frequency signature estimations of the signals, which are sim- ulated with both synthetic and real signals. Notice that in this thesis, we only consider the non-stationary signals with frequency changing slowly with time. It is because the signals with rapidly varying frequency are not sparse in time-frequency domain and then the compressive sensing techniques or sparse reconstructions could not be applied. Also, the data with random missing samples are obtained by randomly choosing the samples’ positions and replacing these samples with zeros.

Стилі APA, Harvard, Vancouver, ISO та ін.

Kinnally, Michael Sean. "Stationary distributions for stochastic delay differential equations with non-negativity constraints." Diss., [La Jolla] : University of California, San Diego, 2009. http://wwwlib.umi.com/cr/ucsd/fullcit?p3355747.

Повний текст джерела

Анотація:

Thesis (Ph. D.)--University of California, San Diego, 2009.
Title from first page of PDF file (viewed June 23, 2009). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references (p. 114-116).

Стилі APA, Harvard, Vancouver, ISO та ін.

Fossi, Fotsi Yannick. "Dynamique morpho-sédimentaire de l’estuaire du Wouri, Cameroun." Thesis, La Rochelle, 2022. http://www.theses.fr/2022LAROS012.

Повний текст джерела

Анотація:

L’estuaire du Wouri, situé au coeur du Golfe de Guinée et ouvert sur l’océan Atlantique est soumis à un large éventail d’influence atmosphérique, océanique, continentale et anthropique à différentes échelles de temps (court et long-terme) contrôlant son évolution. La première partie de cette thèse, axée sur des archives remontant au 20ème siècle, a permis de reconstituer l’histoire de l’évolution du littoral estuarien du Wouri. Parallèlement, pour déterminer les tendances d’évolution des hauteurs d’eau, quantifier et qualifier la cinématique du trait de côte et des fonds dans l’estuaire, un travail d’inventaire, de numérisation et d’analyse des documents historiques a été réalisé. Ceci a permis d’enregistrer une évolution du niveau moyen à un rythme d’environ 25mm/an en 17 ans (2002 – 2019). Les résultats ont révélé une prédominance des variations dominées par l’érosion en aval et inversement par l’accrétion en amont, sur la période de 64 ans (1948-2012). Ces tendances sont accentuées par la présence de facteurs amplificateurs (pression anthropique et changement climatique). Afin d’étudier les processus hydrodynamiques et sédimentaires à court terme, une modélisation numérique de la propagation de la marée et la distribution des salinités et des sédiments fins a été réalisée à l’aide de TELEMAC 3D (calibré et validé grâce aux mesures in-situ acquises au cours de l’année 2019). La marée a montré une asymétrie dominée par le jusant dans sa partie inférieure et inversement par le flot dans sa partie supérieure. La distribution de la salinité a permis de caractériser l’estuaire de bien mélangé en vive-eau, particulièrement en étiage à stratifié en morte eau, particulièrement en période de crue. Les variations saisonnières, du régime fluvial ont montré une migration longitudinale de la position de la zone de turbidité maximale : déplacement en amont pendant les étiages et en aval pendant les crues avec pour conséquence une exportation massive de sédiments dans la partie intermédiaire et aval de l’estuaire. Dans un contexte actuel du changement climatique associé aux forts impacts anthropiques, cette étude souligne la nécessité de l’utilisation des archives historiques, de données in-situ couplées à un modèle numérique pour mieux comprendre l’évolution passée et actuelle de l’hydrodynamique et de la dynamique sédimentaire
The Wouri estuary, located in the heart of the Gulf of Guinea and open to the Atlantic Ocean, is subject to a wide range of atmospheric, oceanic, continental and anthropic influences at different time scales (short and long term) controlling its evolution. The first part of this thesis, based on archives dating back to the 20th century, allows us to reconstruct the history of the evolution of the Wouri estuary coastline. At the same time, in order to determine the evolution trends of the water levels, to quantify and qualify the kinematics of the coastline and the bottoms in the estuary, an inventory, digitization and analysis of historical documents was carried out. This allowed to record an evolution of the average level at a rate of about 25mm/year in 17 years (2002 - 2019). The results revealed a predominance of variations dominated by erosion downstream and conversely by accretion upstream, over the 64-year period (1948-2012). These trends are accentuated by the presence of amplifying factors (anthropogenic pressure and climate change). In order to study the hydrodynamic and sedimentary processes in the short term, a numerical modeling of the tidal propagation and the distribution of salinities and fine sediments was performed using TELEMAC 3D (calibrated and validated thanks to in-situ measurements acquired during 2019). The tide showed an asymmetry dominated by the ebb in its lower part and inversely by the flood in its upper part. The distribution of salinity allowed to characterize the estuary from well mixed in spring tide, particularly in low water to stratified in neap tide, particularly in flood period. Seasonal variations of the river regime have shown a longitudinal migration of the position of the maximum turbidity zone : upstream during low water and downstream during high water with a massive export of sediments in the intermediate and downstream part of the estuary. In a current context of climate change associated with strong anthropogenic impacts, this study highlights the need to use historical archives, in-situ data coupled with a numerical model to better understand the past and present evolution of hydrodynamics and sediment dynamics

Стилі APA, Harvard, Vancouver, ISO та ін.

RANDAZZO, VINCENZO. "Novel neural approaches to data topology analysis and telemedicine." Doctoral thesis, Politecnico di Torino, 2020. http://hdl.handle.net/11583/2850610.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Більше джерел

Книги з теми "Non-stationary distribution"

Coolen, A. C. C., A. Annibale, and E. S. Roberts. Introduction. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780198709893.003.0001.

Повний текст джерела

Анотація:

This introductory chapter sets the scene for the material which follows by briefly introducing the study of networks and describing their wide scope of application. It discusses the role of well-specified random graphs in setting network science onto a firm scientific footing, emphasizing the importance of well-defined null models. Non-trivial aspects of graph generation are introduced. An important distinction is made between approaches that begin with a desired probability distribution on the final graph ensembles and approaches where the graph generation process is the main object of interest and the challenge is to analyze the expected topological properties of the generated networks. At the core of the graph generation process is the need to establish a mathematical connection between the stochastic graph generation process and the stationary probability distribution to which these processes evolve.

Стилі APA, Harvard, Vancouver, ISO та ін.

Tibaldi, Stefano, and Franco Molteni. Atmospheric Blocking in Observation and Models. Oxford University Press, 2018. http://dx.doi.org/10.1093/acrefore/9780190228620.013.611.

Повний текст джерела

Анотація:

The atmospheric circulation in the mid-latitudes of both hemispheres is usually dominated by westerly winds and by planetary-scale and shorter-scale synoptic waves, moving mostly from west to east. A remarkable and frequent exception to this “usual” behavior is atmospheric blocking. Blocking occurs when the usual zonal flow is hindered by the establishment of a large-amplitude, quasi-stationary, high-pressure meridional circulation structure which “blocks” the flow of the westerlies and the progression of the atmospheric waves and disturbances embedded in them. Such blocking structures can have lifetimes varying from a few days to several weeks in the most extreme cases. Their presence can strongly affect the weather of large portions of the mid-latitudes, leading to the establishment of anomalous meteorological conditions. These can take the form of strong precipitation episodes or persistent anticyclonic regimes, leading in turn to floods, extreme cold spells, heat waves, or short-lived droughts. Even air quality can be strongly influenced by the establishment of atmospheric blocking, with episodes of high concentrations of low-level ozone in summer and of particulate matter and other air pollutants in winter, particularly in highly populated urban areas.Atmospheric blocking has the tendency to occur more often in winter and in certain longitudinal quadrants, notably the Euro-Atlantic and the Pacific sectors of the Northern Hemisphere. In the Southern Hemisphere, blocking episodes are generally less frequent, and the longitudinal localization is less pronounced than in the Northern Hemisphere.Blocking has aroused the interest of atmospheric scientists since the middle of the last century, with the pioneering observational works of Berggren, Bolin, Rossby, and Rex, and has become the subject of innumerable observational and theoretical studies. The purpose of such studies was originally to find a commonly accepted structural and phenomenological definition of atmospheric blocking. The investigations went on to study blocking climatology in terms of the geographical distribution of its frequency of occurrence and the associated seasonal and inter-annual variability. Well into the second half of the 20th century, a large number of theoretical dynamic works on blocking formation and maintenance started appearing in the literature. Such theoretical studies explored a wide range of possible dynamic mechanisms, including large-amplitude planetary-scale wave dynamics, including Rossby wave breaking, multiple equilibria circulation regimes, large-scale forcing of anticyclones by synoptic-scale eddies, finite-amplitude non-linear instability theory, and influence of sea surface temperature anomalies, to name but a few. However, to date no unique theoretical model of atmospheric blocking has been formulated that can account for all of its observational characteristics.When numerical, global short- and medium-range weather predictions started being produced operationally, and with the establishment, in the late 1970s and early 1980s, of the European Centre for Medium-Range Weather Forecasts, it quickly became of relevance to assess the capability of numerical models to predict blocking with the correct space-time characteristics (e.g., location, time of onset, life span, and decay). Early studies showed that models had difficulties in correctly representing blocking as well as in connection with their large systematic (mean) errors.Despite enormous improvements in the ability of numerical models to represent atmospheric dynamics, blocking remains a challenge for global weather prediction and climate simulation models. Such modeling deficiencies have negative consequences not only for our ability to represent the observed climate but also for the possibility of producing high-quality seasonal-to-decadal predictions. For such predictions, representing the correct space-time statistics of blocking occurrence is, especially for certain geographical areas, extremely important.

Стилі APA, Harvard, Vancouver, ISO та ін.

Частини книг з теми "Non-stationary distribution"

Cocconcelli, Marco, Radoslaw Zimroz, Riccardo Rubini, and Walter Bartelmus. "Kurtosis over Energy Distribution Approach for STFT Enhancement in Ball Bearing Diagnostics." In Condition Monitoring of Machinery in Non-Stationary Operations, 51–59. Berlin, Heidelberg: Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-642-28768-8_6.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Urbanek, Jacek, Tomasz Barszcz, and Jerome Antoni. "Integrated Modulation Intensity Distribution as a Practical Tool for Condition Monitoring – Part 1: Theoretical Investigation." In Condition Monitoring of Machinery in Non-Stationary Operations, 357–64. Berlin, Heidelberg: Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-642-28768-8_38.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Iribarren, Marcelo, Cesar San Martin, and Pedro Saavedra. "Processing of Non-Stationary Vibrations Using the Affine Wigner Distribution." In Signal Analysis and Prediction, 89–101. Boston, MA: Birkhäuser Boston, 1998. http://dx.doi.org/10.1007/978-1-4612-1768-8_6.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Urbanek, Jacek, Tomasz Barszcz, and Jerome Antoni. "Integrated Modulation Intensity Distribution as a Practical Tool for Condition Monitoring – Part 2: Case Study of the Wind Turbine." In Condition Monitoring of Machinery in Non-Stationary Operations, 365–73. Berlin, Heidelberg: Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-642-28768-8_39.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Zhang, Xiangliang, and Wei Wang. "Self-adaptive Change Detection in Streaming Data with Non-stationary Distribution." In Advanced Data Mining and Applications, 334–45. Berlin, Heidelberg: Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/978-3-642-17316-5_33.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Kayabol, Koray, and Ercan E. Kuruoglu. "Non-stationary t-Distribution Prior for Image Source Separation from Blurred Observations." In Latent Variable Analysis and Signal Separation, 506–13. Berlin, Heidelberg: Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/978-3-642-15995-4_63.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Bojarovich, Julia, and Yuliya Dudovskaya. "Stationary Distribution Insensitivity of a Closed Queueing Network with Non-active Customers." In Communications in Computer and Information Science, 50–58. Cham: Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-13671-4_7.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Bojarovich, Julia, and Yury Malinkovsky. "Stationary Distribution Invariance of an Open Queueing Network with Temporarily Non-active Customers." In Communications in Computer and Information Science, 26–32. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-35980-4_4.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Rouillard, Vincent. "On the Statistical Distribution of Segment Lengths of Road Vehicles Non-Stationary Vibrations." In Experimental Analysis of Nano and Engineering Materials and Structures, 549–50. Dordrecht: Springer Netherlands, 2007. http://dx.doi.org/10.1007/978-1-4020-6239-1_272.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Zhang, Yu, Xiaodong Wang, Zhixiang Min, Shiqiang Wu, Xiufeng Wu, Jiangyu Dai, Fangfang Wang, and Ang Gao. "Adaptive Regulation of Cascade Reservoirs System Under Non-stationary Runoff." In Lecture Notes in Civil Engineering, 985–1000. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-19-6138-0_88.

Повний текст джерела

Анотація:

AbstractUnder the influence of climate change and human activities, the spatial and temporal distribution of river runoff has changed. The statistical characteristics of runoff such as mean, variance and extreme values have changed significantly. Hydrological stationarity has been broken, deepening the uncertainty of water resources and their utilization. Hydrological stationarity is a fundamental assumption of traditional water resources planning and management. The occurrence of non-stationarity will undoubtedly have an impact on the operation and overall benefits of reservoirs, and may even threaten the safety of reservoirs and water resources. There is uncertainty as to whether reservoirs can operate safely and still achieve their design benefits under the new runoff conditions. Therefore, it is important to carry out adaptive regulation of reservoirs in response to non-stationary runoff. Based on the multi-objective theory of large system, a multi-objective joint scheduling model of the terrace reservoir group is constructed for adaptive regulation simulation. A set of combination schemes based on optimal scheduling, flood resource utilization, water saving is constructed. The adaptive regulation is validated using a real-world example of the Xiluodu cascade and Three Gorges cascade reservoirs system in Yangtze River, China. The adaptive regulation processes are analyzed by simulation and the adaptive regulation effects are evaluated. The results show that the non-stationary runoff in upper Yangtze River has had an impact on the comprehensive benefits of large hydropower projects. The use of non-engineering measures to improve flood resource utilization, adjust upstream water use behavior and optimize reservoir scheduling are effective means to reduce the negative impact of non-stationary runoff on cascade reservoirs system.

Стилі APA, Harvard, Vancouver, ISO та ін.

Тези доповідей конференцій з теми "Non-stationary distribution"

Teyssedre, Gilbert, Thi Thu Nga Vu, and Severine Le Roy. "Electric Field Distribution in HVDC Cable Joint in Non-Stationary Conditions." In 2021 IEEE International Conference on the Properties and Applications of Dielectric Materials (ICPADM). IEEE, 2021. http://dx.doi.org/10.1109/icpadm49635.2021.9493863.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Raux, Guillaume, Don R. Halverson, and Hyeon-Cheol Lee. "Empirical Distribution Approach to the Robustness Measure for Non-stationary Data." In 2007 4th International Symposium on Wireless Communication Systems. IEEE, 2007. http://dx.doi.org/10.1109/iswcs.2007.4392337.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Fedorov, Sergey, Yurii Orlov, Andrey Samuylov, Dmitri Moltchanov, Yuliya Gaidamaka, Konstantin Samouylov, and Sergey Shorgin. "SIR Distribution In D2D Environment With Non-Stationary Mobility Of Users." In 31st Conference on Modelling and Simulation. ECMS, 2017. http://dx.doi.org/10.7148/2017-0720.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Karafotis, P. A., and P. S. Georgilakis. "Unbalance and Distortion Evaluation in Three-phase Systems under Non-stationary Conditions." In Mediterranean Conference on Power Generation, Transmission, Distribution and Energy Conversion (MEDPOWER 2018). Institution of Engineering and Technology, 2018. http://dx.doi.org/10.1049/cp.2018.1840.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Nguyen, Yen Thi Hong, Des McLernon, Mounir Ghogho, and Ali Zaidi. "Time-Frequency Distribution for Undersampled Non-stationary Signals using Chirp-based Kernel." In 2018 5th NAFOSTED Conference on Information and Computer Science (NICS). IEEE, 2018. http://dx.doi.org/10.1109/nics.2018.8606839.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Iqbal, Rauf, Thushara Abhayapala, Javed Ahmed, and Tharaka Lamahewa. "Wigner-Ville distribution of a type of non-stationary mobile Rayleigh fading channels." In 2009 IEEE 13th International Multitopic Conference (INMIC). IEEE, 2009. http://dx.doi.org/10.1109/inmic.2009.5383132.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Condron, J. "Comparison of time-frequency distribution techniques using multi-component non-stationary test signals." In IEE Irish Signals and Systems Conference 2005. IEE, 2005. http://dx.doi.org/10.1049/cp:20050322.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

"AN INVESTIGATION INTO THE DISTRIBUTION OF MEMBERSHIP GRADES FOR NON-STATIONARY FUZZY SETS." In International Conference on Fuzzy Computation. SciTePress - Science and and Technology Publications, 2009. http://dx.doi.org/10.5220/0002321400790084.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Lua, James, and E. Thomas Mover. "First-Excursion Probability and Response Peak Distribution of a Nonlinear Structure Under Non-Gaussian Non-Stationary Loadings." In ASME 1998 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 1998. http://dx.doi.org/10.1115/imece1998-0392.

Повний текст джерела

Анотація:

Abstract Probabilistic methods have been used recently for the reliability assessment and design of ship structures because of the presence of various uncertainties in structural configuration, material properties, and environmental and operating conditions. Among these uncertainties, random dynamic loads induced by either sea waves or slamming play a significant role in reliability-based ship structural design. The present state-of-the-art probabilistic method for ship design is based on a linear structural response model subjected to stationary Gaussian random processes. However, under extreme operating conditions, the ship structural response may not be linear due to the initiation and evolution of multiple local damage, such as local plastic deformation, stiffener tripping, panel buckling, or fracture. In addition, the complexity of fluid-structure interaction phenomena may render the assumptions on the loading process (stationary and Gaussian) invalid. Under this study, we developed a simulation based probabilistic analysis framework for a nonlinear dynamic structural system under non-Gaussian non-stationary loadings. The general simulation based probabilistic analysis framework (SIMLAB) is formulated by integrating 1) random variable generating modules; 2) random process generation modules; and 3) user selected deterministic solver and limit state function. The developed random process simulation module is able to generate a Gaussian, non-Gaussian, stationary, or non-stationary process. To demonstrate the applicability of the developed tool for a structural dynamic system with random variables and random processes, a free-free beam subjected to a sea wave induced random process is solved by integrating a structural dynamics code, DYNA3D, with the developed probabilistic analysis framework. The limit state function is formulated based on the first crossing of a beam Von Mises stress at an integration point above a safe threshold. In order to validate the accuracy of SIMLAB, a linear beam structure subjected to a stationary Gaussian process is considered first and the simulated statistical distributions of peak and extreme response variables are compared with analytical predictions. The effect of material nonlinearity on probability of failure and peak statistics is explored by using an elastoplastic beam model subjected to a random excitation. Results on probability of failure and peak statistics are compared with the corresponding statistical models for a linear structure. The great versatility of the simulation based probabilistic analysis framework provides us a solid foundation for the development of more advanced probabilistic analysis tools for reliability-based ship design.

Стилі APA, Harvard, Vancouver, ISO та ін.

De Luca, Davide Luciano, Benedetta Moccia, Fabio Russo, and Francesco Napolitano. "Stationary/Non-Stationary Modelling for Extreme Value Distribution: Analysis of Rainfall Annual Maxima in Italy in a Climate Change Context." In EWaS5. Basel Switzerland: MDPI, 2022. http://dx.doi.org/10.3390/environsciproc2022021065.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Звіти організацій з теми "Non-stationary distribution"

Ho, Hwai-Chung, and Tze-Chien Sun. Limiting Distributions of Non-Linear Vector Functions of Stationary Gaussian Processes. Fort Belvoir, VA: Defense Technical Information Center, March 1988. http://dx.doi.org/10.21236/ada194569.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Ми пропонуємо знижки на всі преміум-плани для авторів, чиї праці увійшли до тематичних добірок літератури. Зв'яжіться з нами, щоб отримати унікальний промокод!