Bibliografie tematiche / Random observations

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Letteratura scientifica selezionata sul tema "Random observations"

Autore: Grafiati
Pubblicato: 5 ottobre 2024

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Articoli di riviste sul tema "Random observations"

1

Jaynes, E. T. "Some random observations". Synthese 63, n. 1 (aprile 1985): 115–38. http://dx.doi.org/10.1007/bf00485957.

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Andrea, Montanari. "Estimating random variables from random sparse observations". European Transactions on Telecommunications 19, n. 4 (2008): 385–403. http://dx.doi.org/10.1002/ett.1289.

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Sanandaji, Borhan M., Michael B. Wakin e Tyrone L. Vincent. "Observability With Random Observations". IEEE Transactions on Automatic Control 59, n. 11 (novembre 2014): 3002–7. http://dx.doi.org/10.1109/tac.2014.2351693.

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O’Neill, Cecily. "Seal Wife – random observations". NJ 41, n. 1 (2 gennaio 2017): 27–29. http://dx.doi.org/10.1080/14452294.2017.1329687.

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5

Schmidt, Marius, e Rainer Schwabe. "Optimal cutpoints for random observations". Statistics 49, n. 6 (17 febbraio 2015): 1366–81. http://dx.doi.org/10.1080/02331888.2015.1006225.

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WILLIAMS, J. "Random observations on reading research". Issues in Education 5, n. 1 (1999): 161–64. http://dx.doi.org/10.1016/s1080-9724(99)00013-0.

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Zirbel, Craig L. "Lagrangian observations of homogeneous random environments". Advances in Applied Probability 33, n. 4 (dicembre 2001): 810–35. http://dx.doi.org/10.1239/aap/1011994031.

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This article deals with the distribution of the view of a random environment as seen by an observer whose location at each moment is determined by the environment. The main application is in statistical fluid mechanics, where the environment consists of a random velocity field and the observer is a particle moving in the velocity field, possibly subject to molecular diffusion. Several results on such Lagrangian observations of the environment have appeared in the literature, beginning with the 1957 dissertation of J. L. Lumley. This article unites these results into a simple unified framework and rounds out the theory with new results in several directions. When the environment is homogeneous, the problem can be re-cast in terms of certain random mappings on the physical space that are based on the random location of the observer. If these mappings preserve the invariant measure on the physical space, then the view from the random location has the same distribution as the view from the origin. If these mappings satisfy the flow property and the environment is stationary, then the succession of Lagrangian observations over time forms a strictly stationary process. In particular, for motion in a homogeneous, stationary, and nondivergent velocity field, the Lagrangian velocity (the velocity of the particle) is strictly stationary, which was first observed by Lumley. In the compressible case, the distribution of a Lagrangian observation has a density with respect to the distribution of the view from the origin, and in some cases convergence in distribution of the Lagrangian observations as time tends to infinity can be shown.
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Zirbel, Craig L. "Lagrangian observations of homogeneous random environments". Advances in Applied Probability 33, n. 04 (dicembre 2001): 810–35. http://dx.doi.org/10.1017/s0001867800011216.

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This article deals with the distribution of the view of a random environment as seen by an observer whose location at each moment is determined by the environment. The main application is in statistical fluid mechanics, where the environment consists of a random velocity field and the observer is a particle moving in the velocity field, possibly subject to molecular diffusion. Several results on such Lagrangian observations of the environment have appeared in the literature, beginning with the 1957 dissertation of J. L. Lumley. This article unites these results into a simple unified framework and rounds out the theory with new results in several directions. When the environment is homogeneous, the problem can be re-cast in terms of certain random mappings on the physical space that are based on the random location of the observer. If these mappings preserve the invariant measure on the physical space, then the view from the random location has the same distribution as the view from the origin. If these mappings satisfy the flow property and the environment is stationary, then the succession of Lagrangian observations over time forms a strictly stationary process. In particular, for motion in a homogeneous, stationary, and nondivergent velocity field, the Lagrangian velocity (the velocity of the particle) is strictly stationary, which was first observed by Lumley. In the compressible case, the distribution of a Lagrangian observation has a density with respect to the distribution of the view from the origin, and in some cases convergence in distribution of the Lagrangian observations as time tends to infinity can be shown.
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Cohen, Joel E., e Thomas M. Liggett. "Random arithmetic-geometric means and random pi: observations and conjectures". Stochastic Processes and their Applications 41, n. 2 (giugno 1992): 261–71. http://dx.doi.org/10.1016/0304-4149(92)90126-b.

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Eather, Wolfgang, e Matthias Albbecht. "Linear Eegression with Random Fuzzy Observations". Statistics 21, n. 4 (gennaio 1990): 521–31. http://dx.doi.org/10.1080/02331889008802262.

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Tesi sul tema "Random observations"

1

Brophy, Edmond M. "Prophet Inequalities for Multivariate Random Variables with Cost for Observations". Thesis, University of North Texas, 2019. https://digital.library.unt.edu/ark:/67531/metadc1538720/.

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In prophet problems, two players with different levels of information make decisions to optimize their return from an underlying optimal stopping problem. The player with more information is called the "prophet" while the player with less information is known as the "gambler." In this thesis, as in the majority of the literature on such problems, we assume that the prophet is omniscient, and the gambler does not know future outcomes when making his decisions. Certainly, the prophet will get a better return than the gambler. But how much better? The goal of a prophet problem is to find the least upper bound on the difference (or ratio) between the prophet's return, M, and the gambler's return, V. In this thesis, we present new prophet problems where we seek the least upper bound on M-V when there is a fixed cost per observations. Most prophet problems in the literature compare M and V when prophet and gambler buy (or sell) one asset. The new prophet problems presented in Chapters 3 and 4 treat a scenario where prophet and gambler optimize their return from selling two assets, when there is a fixed cost per observation. Sharp bounds for the problems on small time horizons are given; for the n-day problem, rough bounds and a description of the distributions for the random variables that maximize M-V are presented.
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2

Mohammed, Hussein Syed. "Random feature subspace ensemble based approaches for the analysis of data with missing features /". Full text available online, 2006. http://www.lib.rowan.edu/find/theses.

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3

Rochet, Jean. "Isolated eigenvalues of non Hermitian random matrices". Thesis, Sorbonne Paris Cité, 2016. http://www.theses.fr/2016USPCB030/document.

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Dans cette thèse, il est question de spiked models pour des matrices aléatoires nonhermitiennes. Plus précisément, on considère des matrices de type A+P, tel que le rang de P reste borné indépendamment de la taille de la matrice qui tend vers l’infini, et tel que A est une matrice aléatoire non-hermitienne. Tout d’abord, on prouve que dans le cas où la matrice P possède des valeurs propres hors du bulk, quelques valeurs propres de A+P (appelées outliers) apparaissent loin de celui-ci. Ensuite, on regarde les fluctuations des outliers de A autour de leurs limites et on montre que celles-ci ont la même distribution que les valeurs propres d’une certaine matrice aléatoire de taille finie. Ce genre de phénomène avait déjà été observé pour des modèles hermitiens. De manière inattendue, on montre que les vitesses de convergence des outliers varient (en fonction de la Réduite de Jordan de P) et que des corrélations peuvent apparaître entre des outliers situés à une distance macroscopique l’un de l’autre. Le premier modèle de matrices non-hermitiennes que l’on considère provient du théorème du Single Ring que l’on doit à Guionnet, Krishnapur et Zeitouni. Un autre modèle étudié est celui des matrices dites “presque” hermitiennes : c’est-à-dire lorsque A est hermitienne mais P ne l’est pas. Enfin, on regarde aussi les outliers pour des matrices Elliptiques Gaussiennes. Cette thèse traite aussi de la convergence en loi de variables aléatoires du type Tr( f (A)M) où A est une matrice du théorème du Single Ring et f est une fonction holomorphe sur un voisinage du bulk et la norme de Frobenius de M est de l’ordre de √N. En corollaire de ce résultat, on obtient des théorèmes type “Centrale Limite” pour les statistiques linéaires de A (pour des fonctions tests holomorphes) et des projections de rang finies de la matrice A (comme par exemple les entrées de la matrice)
This thesis is about spiked models of non Hermitian random matrices. More specifically, we consider matrices of the type A+P, where the rank of P stays bounded as the dimension goes to infinity and where the matrix A is a non Hermitian random matrix. We first prove that if P has some eigenvalues outside the bulk, then A+P has some eigenvalues (called outliers) away from the bulk. Then, we study the fluctuations of the outliers of A around their limit and prove that they are distributed as the eigenvalues of some finite dimensional random matrices. Such facts had already been noticed for Hermitian models. More surprising facts are that outliers can here have very various rates of convergence to their limits (depending on the Jordan Canonical Form of P) and that some correlations can appear between outliers at a macroscopic distance from each other. The first non Hermitian model studied comes from the Single Ring Theorem due to Guionnet, Krishnapur and Zeitouni. Then we investigated spiked models for nearly Hermitian random matrices : where A is Hermitian but P isn’t. At last, we studied the outliers of Gaussian Elliptic random matrices. This thesis also investigates the convergence in distribution of random variables of the type Tr( f (A)M) where A is a matrix from the Single Ring Theorem and f is analytic on a neighborhood of the bulk and the Frobenius norm of M has order √N. As corollaries, we obtain central limit theorems for linear spectral statistics of A (for analytic test functions) and for finite rank projections of f (A) (like matrix entries)
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4

Alemdar, Meltem. "A Monte Carlo study the impact of missing data in cross-classification random effects models /". Atlanta, Ga. : Georgia State University, 2008. http://digitalarchive.gsu.edu/eps_diss/34/.

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Thesis (Ph. D.)--Georgia State University, 2008.
Title from title page (Digital Archive@GSU, viewed July 20, 2010) Carolyn F. Furlow, committee chair; Philo A. Hutcheson, Phillip E. Gagne, Sheryl A. Gowen, committee members. Includes bibliographical references (p. 96-100).
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5

Iufereva, Olga. "Algorithmes de filtrage avec les observations distribuées par Poisson". Electronic Thesis or Diss., Université de Toulouse (2023-....), 2024. https://theses.hal.science/tel-04720020.

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La théorie du filtrage concerne essentiellement l’estimation optimale de l’état dans les systèmes stochastiques, surtout avec des mesures partielles et bruitées. Ce domaine, fortement lié à la théorie du contrôle, se concentre sur la synthèse d'estimateurs effectuant des calculs en temps réel pour minimiser l'erreur quadratique moyenne. La nécessité de telles estimations devient de plus en plus critique avec la prolifération de systèmes contrôlés par réseau, tels que les véhicules autonomes et les processus industriels complexes, où les processus d'observations sont soumis au caractère aléatoire de la transmission, ce qui donne lieu à des modèles d'information variables pour résoudre le problème d'estimation.Cette thèse aborde la tâche importante de l'estimation d'état dans les systèmes dynamiques stochastiques en temps continu lorsque les mesures sont disponible aux certains instants discrets defini par un processus aléatoire. En adaptant les méthodes d'estimation classiques, nous développons des équations pour un estimateur optimal d'état, explorons leurs propriétés et les aspect pratiques, et proposons et analysons des alternatives sous-optimales, présentant des parallèles avec les techniques existantes dans le domaine d'estimation classique lorsqu'elles sont appliquées aux processus d'observation Poisson-distribués.L'étude couvre trois classes de modèles mathématiques pour le système dynamique en temps continu et le processus d'observation discret. Tout d’abord, nous considérons des équations différentielles Ito-stochastiques avec le champ de vecteur Lipschitz et un coefficient de diffusion constant, alors que le processus d’observation discrète de dimension inférieure comprend la fonction nonlinéaire de l’état et un bruit Gaussien additif. Nous proposons des estimateurs d’état sous-optimaux continus-discrets, qui sont faciles à implémenter pour cette classe de systèmes. En supposant qu'un compteur de Poisson décrit les instants discrets auxquels les observations sont disponibles, nous calculons le processus de covariance d’erreur d’estimation. L'analyse est effectuée pour fournir les conditions de limitation du processus de covariance d'erreur, ainsi que la dépendance au taux d'échantillonnage moyen.Deuxièmement, nous considérons les systèmes dynamiques décrits par des chaînes de Markov en temps continu avec un espace d'état fini, et le processus d'observation est obtenu en discrétisant un processus stochastique conventionnel piloté par un processus de Wiener. Dans ce cas, nous montrons la convergence $L_1$ de l'estimateur optimal vers l'estimateur optimal classique (purement continu) (filtre de Wonham) quand l'intensité des processus de Poisson augmente.Enfin, nous étudions les filtres à particules continus-discrets pour les processus d'Ornstein-Uhlenbeck avec des observations discrètes décrites par des fonctions d'état linéaires et un bruit Gaussien additif. Les filtres à particules ont gagné beaucoup d'intérêt pour l'estimation d'état dans les modèles à grande échelle avec des mesures bruitées où le calcul du gain optimal est soit coûteux en calcul, soit pas entièrement réalisable en raison de la complexité de la dynamique. Dans cette thèse, nous proposons des processus de diffusion de type McKean–Vlasov continus-discrets, qui servent de modèle de champ moyen pour décrire la dynamique des particules. Nous étudions plusieurs types de processus de champ moyen en fonction de la manière dont les termes de bruit sont inclus pour l'imitation du processus d'état et du modèle d'observation. Les particules résultantes sont couplées via des covariances empiriques qui sont mises à jour en temps discrets avec l'arrivée de nouvelles observations. Avec une analyse appropriée des premier et deuxième instants, nous montrons que sous certaines conditions sur les paramètres du système, les performances des filtres à particules se rapprochent du filtre optimal quand le nombre de particules augmente
Filtering theory basically relates to optimal state estimation in stochastic dynamical systems, particularly when faced with partial and noisy data. This field, closely intertwined with control theory, focuses on designing estimators doing real-time computation while maintaining an acceptable level of accuracy as measured by the mean square error. The necessity for such estimates becomes increasingly critical with the proliferation of network-controlled systems, such as autonomous vehicles and complex industrial processes, where the observation processes are subject to randomness in transmission and this gives rise to varying information patterns under which the estimation must be carried out.This thesis addresses the important task of state estimation in continuous-time stochastic dynamical systems when the observation process is available only at some discrete time instants governed by a random process. By adapting classical estimation methods, we derive equations for optimal state estimator, explore their properties and practicality, and propose and evaluates sub-optimal alternatives, showcasing parallels to the existing techniques within the classical estimation domain when applied to Poisson-distributed observation processes.The study covers three classes of mathematical models for the continuous-time dynamical system and the discrete observation process. First, we consider Ito-stochastic differential equations with Lipschitz drift terms and constant diffusion coefficient, whereas the lower-dimensional discrete observation process comprises the nonlinear mapping of the state and additive Gaussian noise. We propose easy-to-implement continuous-discrete suboptimal state estimators for this system class. Assuming that a Poisson counter governs discrete times at which the observations are available, we compute the expectation or error covariance process. Analysis is carried out to provide conditions for boundedness of the error covariance process, as well as, the dependence on the mean sampling rate.Secondly, we consider the dynamical systems described by continuous-time Markov chains with finite state space, and the observation process is obtained by discretizing a conventional stochastic process driven by a Wiener process. For this case, the $L_1$-convergence of the derived optimal estimator to the classical (purely continuous) optimal estimator (Wonham filter) is shown with respect to increasing intensity of Poisson processes.Lastly, we study continuous-discrete particle filters for Ornstein-Uhlenbeck processes with discrete observations described by linear functions of state and additive Gaussian noise. Particle filters have gained a lot of interest for state estimation in large-scale models with noisy measurements where the computation of optimal gain is either computationally expensive or not entirely feasible due to complexity of the dynamics. In this thesis, we propose continuous-discrete McKean–Vlasov type diffusion processes, which serve as the mean-field model for describing the particle dynamics. We study several kinds of mean-field processes depending on how the noise terms are included in mimicking the state process and the observation model. The resulting particles are coupled through empirical covariances which are updated at discrete times with the arrival of new observations. With appropriate analysis of the first and second moments, we show that under certain conditions on system parameters, the performance of the particle filters approaches the optimal filter as the number of particles gets larger
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Johansson, Åsa M. "Methodology for Handling Missing Data in Nonlinear Mixed Effects Modelling". Doctoral thesis, Uppsala universitet, Institutionen för farmaceutisk biovetenskap, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-224098.

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To obtain a better understanding of the pharmacokinetic and/or pharmacodynamic characteristics of an investigated treatment, clinical data is often analysed with nonlinear mixed effects modelling. The developed models can be used to design future clinical trials or to guide individualised drug treatment. Missing data is a frequently encountered problem in analyses of clinical data, and to not venture the predictability of the developed model, it is of great importance that the method chosen to handle the missing data is adequate for its purpose. The overall aim of this thesis was to develop methods for handling missing data in the context of nonlinear mixed effects models and to compare strategies for handling missing data in order to provide guidance for efficient handling and consequences of inappropriate handling of missing data. In accordance with missing data theory, all missing data can be divided into three categories; missing completely at random (MCAR), missing at random (MAR) and missing not at random (MNAR). When data are MCAR, the underlying missing data mechanism does not depend on any observed or unobserved data; when data are MAR, the underlying missing data mechanism depends on observed data but not on unobserved data; when data are MNAR, the underlying missing data mechanism depends on the unobserved data itself. Strategies and methods for handling missing observation data and missing covariate data were evaluated. These evaluations showed that the most frequently used estimation algorithm in nonlinear mixed effects modelling (first-order conditional estimation), resulted in biased parameter estimates independent on missing data mechanism. However, expectation maximization (EM) algorithms (e.g. importance sampling) resulted in unbiased and precise parameter estimates as long as data were MCAR or MAR. When the observation data are MNAR, a proper method for handling the missing data has to be applied to obtain unbiased and precise parameter estimates, independent on estimation algorithm. The evaluation of different methods for handling missing covariate data showed that a correctly implemented multiple imputations method and full maximum likelihood modelling methods resulted in unbiased and precise parameter estimates when covariate data were MCAR or MAR. When the covariate data were MNAR, the only method resulting in unbiased and precise parameter estimates was a full maximum likelihood modelling method where an extra parameter was estimated, correcting for the unknown missing data mechanism's dependence on the missing data. This thesis presents new insight to the dynamics of missing data in nonlinear mixed effects modelling. Strategies for handling different types of missing data have been developed and compared in order to provide guidance for efficient handling and consequences of inappropriate handling of missing data.
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Bourmani, Sabrina. "Binary decision for observations with unknown distribution : an optimal and invariance-based framework". Thesis, Ecole nationale supérieure Mines-Télécom Atlantique Bretagne Pays de la Loire, 2020. http://www.theses.fr/2020IMTA0173.

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A travers ma thèse, nous nous sommes intéressés à la décision binaire quand lesignal d’intérêt est supposé aléatoire de distribution inconnue. Dans la littérature classique, cegenre de scénario de détection n’offre pas beaucoup de possibilités de résolution qui garantissent une certaine optimalité. À notre connaissance, seule l’approche RDT traite de ce genre de problèmes en assurant une certaine optimalité. C’est ainsi que, durant ma thèse, nous avons tout d’abord étendu l’approche RDT dans le cadre d’une configuration distribuée, toujours en considérant le signal aléatoire de distribution inconnue. Ensuite, nous avons généralisé le RDT pour le cas d’un bruit non-Gaussien (GRDT). Enfin nous nous sommes orienté vers le cadre asymptotique dans l’espoir de dépasser les limites du GRDT. Pour ce faire, nous avons considéré un model simple de signaux déterministes et nous avons démontré une formulation asymptotique du théorème de Karlin-Rubin. Tous nos travaux se sont basés sur la notion clé d’invariance que nous avons redéfinie pour convenir à une classe de problèmes de décision plus générale, i.e. quand la distribution du signal d’intérêt n’est pas connue. Outre la notion d’invariance, l’optimalité a aussi eu une place importante dans les directions que nous avons considérées étant donné l’esprit de nos travaux
During my thesis, we took interest in decision problems where signals are assumed to be stochastic with unknown distributions. In standard literature, such an assumption does not allow to seek solutions that guarantees a certain optimality. At least, aside from the RDT framework developed a few years ago in our laboratory. Hence, we took interest in the philosophy behind the RDT framework, and we follow the same guidelines concerning the unknown distribution of the signal. Apart from our optimality purposes, we also have an invariance based perspective in how we intend to solve this type of decision problems. Indeed, when there are uncertainties about the signal of interest, we can try to derive solutions that are invariant towards them. These are the two key notions we consider throughout our investigations. In this manuscript, first, we apply the RDT framework for a distributed decision to test its suitability to such decision scenarios where the signal of interest is random of unknown distribution and where the observations are collected by a network of sensors instead of just one sensor. Then, we generalise the theoretical material of the RDT framework to when the noise is not necessary Gaussian while still considering the signal of interest random of unknown distribution. Finally, we adopt an asymptotic outlook to circumvent the limitations of the RDT and the developed GRDT approach. Although the considered decision scenarios concern unconditional models in the simple case of deterministic signals, it allows to think ahead of the eventual upcoming generalisations in the asymptotic scope
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Martinez, Garcia Alba Maria. "Study of the Resistive Switching Mechanism in Novel Ultra-thin Organic-inorganic Dielectric-based RRAM through Electrical Observations". Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-299358.

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The promising role resistive random-access memory (RRAM) plays in the imminent reality of wearable electronics calls for a new, updated physical model of their operating mechanism. Their high applicability as the next-generation flexible non-volatile memory (NVM) devices has promoted the recent emergence of a novel ultra-thin (< 5nm) organic/inorganic hybrid dielectric RRAM. A deep understanding of their resistive switching (RS) behavior is required to unlock their suitability in future electronics applications. However, the extremely reduced thicknesses bring about new challenges in terms of material characterization sample processing, while the RS observations through electrical characterization techniques lack uniformity in the key switching parameters, thus hindering the identification of any clear trends.  This work studies the RS mechanism in ultra-thin Al/Hf-hybrid/Ni RRAM devices through uniformity-improved electrical observations. First, the focus is to implement a ramped-pulse train method during the reset process to reduce the dispersion of the voltage and resistance fluctuations at different starting voltage amplitudes and pulse widths. After finding the optimal electrical programming conditions for reduced parameter dispersions, a temperature test was performed to study the contributions of the metal ions and oxygen vacancies (V2+) in the switching layer. Finally, a physical model describing the operating mechanism in flexible RRAM is proposed after the close observation and study of the processed devices. The model is based on the coexistence of a hetero-metallic portion composed of Al and Hf3Al2, and a V2+ portion connected to form the hybrid conducting filament (CF) and turning the device on. The CF forming processes emphasize the strong presence of these vacancies partaking in RS, as the temperature dependence results suggest the majority of their concentration to be generated during this step. Also, the different electrical potential, temperature, and concentration gradients influencing the V2+ migration during RS may explain some of the failure mechanisms in the rupture and the re-forming of the filament. Additionally, the possible presence of a thin Al-oxide layer in the Al/Hf-hybrid interface may give a reason for leaky on-states. A detailed physical model of the RS mechanism in next-generation flexible RRAMs is key to learn to unlock a range of emerging technologies fitted to today’s needs.
Den senaste introduktionen av ultratunn (<5 nm) organisk-oorganisk hybrid dielektrisk RRAM som nästa generations icke-flyktiga minnesenheter kräver en djup förståelse för hybridskiktresistiv växling (RS). Den extremt reducerade tjockleken hindrar emellertid deras bearbetbarhet för materialkarakteriseringstekniker. Dessutom hindrar den dåliga enhetligheten i viktiga omkopplingsparametrar fortfarande i RRAM att alla trender kan definieras tydligt genom elektrisk karakterisering. Detta arbete använder elektrisk manipulation genom en RPS-metod (ramped-pulse series) för att förbättra spännings- och motståndsfluktuationerna i återställningsprocessen för ultratunna Al/Hf-hybrid/Ni-enheter vid olika spänningsamplitud, pulsbredd och temperaturförhållanden. Från de erhållna RPS-optimerade resultaten föreslås en ny och detaljerad fysisk modell som beskriver driftsmekanismen. Samexistensen i den ledande filamenten (CF) av en hybridmetalldel, sammansatt av Al och Hf3Al2, och en syrevakansdel bekräftas. Vår modell betonar vakansbidraget i RS, där majoriteten genereras under CF-formningsprocessen och deltar i olika grad i filamentbrottet för RPS och ingen RPS-bearbetade enheter via Joule-uppvärmning, drift och Fick-krafter. Dessutom förklaras kopplingsfelhändelser baserat på närvaron av ett Al2O3-lager i Al/Hf-hybridgränssnittet.
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Wabiri, Njeri. "Variable modeling of spatially distributed random interval observation". Doctoral thesis, University of Cape Town, 2007. http://hdl.handle.net/11427/4365.

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Arrowood, Jon A. "Using observation uncertainty for robust speech recognition". Diss., Available online, Georgia Institute of Technology, 2004:, 2003. http://etd.gatech.edu/theses/available/etd-04082004-180005/unrestricted/arrowood%5Fjon%5Fa%5F200312%5Fphd.pdf.

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Libri sul tema "Random observations"

1

University, Emory, a cura di. I have never tasted any bad ice cream and other random observations. Decatur, G.A: Looking Glass Books, 1997.

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2

Weinberg, Israel Louis. Settings at random: Observations, experiences, ideas : Brick Lane, London E1, 1915-1987. [Wembley] (]28, Blenheim Gardens, East Lane, Wembley, HA9 7NP]): [I.L. Weinberg], 1987.

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Hyde, Henry J. Catch the burning flag: Speeches and random observations of Henry Hyde ; [foreword by Robert Novak]. New York: National Review Books, 2008.

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Näther, Wolfgang. Effective observation of random fields. Leipzig: Teubner, 1985.

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Davies, Merton E. Rand's role in the evolution of balloon and satellite observation systems and related U.S. space technology. Santa Monica, CA: Rand Corp., 1988.

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Short, Nevil. Random Observations. Unknown Publisher, 2021.

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Richard, Smith. Random Observations. Certainty Perspectives, 2020.

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Maready, Kenan. Random Thoughts and Observations. Independently Published, 2019.

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McWhorter, Jenn. Random Rants and Other Observations. Lulu Press, Inc., 2008.

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Single Exposures (Random Observations on Photography, Art & Creativity). LensWork Publishing, 2005.

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Più fonti

Capitoli di libri sul tema "Random observations"

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Azencott, Robert, e Didier Dacunha-Castelle. "Discrete Time Random Processes". In Series of Irregular Observations, 3–9. New York, NY: Springer New York, 1986. http://dx.doi.org/10.1007/978-1-4612-4912-2_2.

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Azencott, Robert, e Didier Dacunha-Castelle. "Random Fields and Stochastic Integrals". In Series of Irregular Observations, 37–45. New York, NY: Springer New York, 1986. http://dx.doi.org/10.1007/978-1-4612-4912-2_6.

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Näther, Wolfgang, e Ralf Körner. "Linear regression with random fuzzy observations". In Statistical Modeling, Analysis and Management of Fuzzy Data, 282–305. Heidelberg: Physica-Verlag HD, 2002. http://dx.doi.org/10.1007/978-3-7908-1800-0_18.

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Morales, Domingo, Leandro Pardo e Igor Vajda. "Digitalization of Observations Permits Efficient Estimation in Continuous Models". In Soft Methodology and Random Information Systems, 315–22. Berlin, Heidelberg: Springer Berlin Heidelberg, 2004. http://dx.doi.org/10.1007/978-3-540-44465-7_38.

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Sabre, Rachid. "Evolutionary Spectrum for Random Field and Missing Observations". In Lecture Notes in Computer Science, 209–16. Berlin, Heidelberg: Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-642-31254-0_24.

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Gouet, Raúl, Miguel Lafuente, F. Javier López e Gerardo Sanz. "$$\delta $$ δ -Records Observations in Models with Random Trend". In Studies in Systems, Decision and Control, 209–17. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-73848-2_20.

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Chazelle, Bernard. "Some Observations on Dynamic Random Walks and Network Renormalization". In Fundamentals of Computation Theory, 18–28. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-25027-0_2.

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Walrand, Jean. "Tracking—A". In Probability in Electrical Engineering and Computer Science, 163–92. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-49995-2_9.

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AbstractThis chapter explains how to estimate an unobserved random variable or vector from available observations. This problem arises in many examples, as illustrated in Sect. 9.1. The basic problem is defined in Sect. 9.2. One commonly used approach is the linear least squares estimate explained in Sect. 9.3. A related notion is the linear regression covered in Sect. 9.4. Section 9.5 comments on the problem of overfitting. Sections 9.6 and 9.7 explain the minimum means squares estimate that may be a nonlinear function of the observations and the remarkable fact that it is linear for jointly Gaussian random variables. Section 9.8 is devoted to the Kalman filter, which is a recursive algorithm for calculating the linear least squares estimate of the state of a system given previous observations.
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Badings, Thom, Matthias Volk, Sebastian Junges, Marielle Stoelinga e Nils Jansen. "CTMCs with Imprecisely Timed Observations". In Tools and Algorithms for the Construction and Analysis of Systems, 258–78. Cham: Springer Nature Switzerland, 2024. http://dx.doi.org/10.1007/978-3-031-57249-4_13.

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AbstractLabeled continuous-time Markov chains (CTMCs) describe processes subject to random timing and partial observability. In applications such as runtime monitoring, we must incorporate past observations. The timing of these observations matters but may be uncertain. Thus, we consider a setting in which we are given a sequence of imprecisely timed labels called the evidence. The problem is to compute reachability probabilities, which we condition on this evidence. Our key contribution is a method that solves this problem by unfolding the CTMC states over all possible timings for the evidence. We formalize this unfolding as a Markov decision process (MDP) in which each timing for the evidence is reflected by a scheduler. This MDP has infinitely many states and actions in general, making a direct analysis infeasible. Thus, we abstract the continuous MDP into a finite interval MDP (iMDP) and develop an iterative refinement scheme to upper-bound conditional probabilities in the CTMC. We show the feasibility of our method on several numerical benchmarks and discuss key challenges to further enhance the performance.
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Wei, Zheng, Tonghui Wang e Baokun Li. "On Consistency of Estimators Based on Random Set Vector Observations". In Causal Inference in Econometrics, 185–98. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-27284-9_11.

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Atti di convegni sul tema "Random observations"

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Prasad, J. V. R., Vinodhini Comandur, Robert Walters e David Guerrero. "Model Predictive Path Integral Approach for Trajectory Guidance of Rotorcraft Shipboard Landing". In Vertical Flight Society 80th Annual Forum & Technology Display, 1–16. The Vertical Flight Society, 2024. http://dx.doi.org/10.4050/f-0074-2018-12780.

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Rotorcraft shipboard landing continues to be challenging due to increased pilot workload in dealing with effects of ship air wake turbulence on vehicle motion and random ship motion. Some of the recent work has proposed a pilot assist function for reduced pilot workload using model predictive control methods. This paper explores the use of a recently developed Model Predictive Path Integral (MPPI) method based on a stochastic optimal control framework for trajectory guidance solution to the shipboard landing problem. First, a proof-of-concept study is presented by applying the MPPI method to a simple point mass approximation of helicopter dynamics represented in the form of a first-order command acceleration model, representative of helicopter trajectory motion in the vertical plane. Next, the MPPI method is used in conjunction with a six degrees-of-freedom linear model of a helicopter in order to gain further insight into the applicability of the MPPI framework to the rotorcraft shipboard landing problem. The paper concludes with key observations and inferences gained in this study.
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Jie, Zhang, Lu Huiguo e Luo Yangyi. "Spatial Consistency Test Method for Meteorological Data Based On Random Forest". In 2019 International Conference on Meteorology Observations (ICMO). IEEE, 2019. http://dx.doi.org/10.1109/icmo49322.2019.9026034.

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Zafarani, Reza, e Ali A. Ghorbani. "Oracle Clustering: Dynamic Partitioning Based on Random Observations". In 2008 20th IEEE International Conference on Tools with Artificial Intelligence (ICTAI). IEEE, 2008. http://dx.doi.org/10.1109/ictai.2008.128.

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Huang, Wubin, Yingsha Jiang, Xinwei Liu, Yongjie Pan, Xia Li, Runxia Guo, Yuxia Huang e Bolong Duan. "Classified Early-warning and Nowcasting of Hail Weather Based on Radar Products and Random Forest Algorithm". In 2019 International Conference on Meteorology Observations (ICMO). IEEE, 2019. http://dx.doi.org/10.1109/icmo49322.2019.9026039.

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Xu, Kaiqin, Zhijian Cai e Jianhong Wu. "Random pixelated grating computational spectrometer based on deep learning". In Conference on Novel Technologies and Instruments for Astronomical Multi-Band Observations, a cura di Suijian Xue e Yongtian Zhu. SPIE, 2021. http://dx.doi.org/10.1117/12.2607021.

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Boldyrikhin, Nikolay V., Olga A. Safaryan e Alexey A. Svizhenko. "Optimization of Observations for a Limited Flow of Random Processes". In 2021 Radiation and Scattering of Electromagnetic Waves (RSEMW). IEEE, 2021. http://dx.doi.org/10.1109/rsemw52378.2021.9494057.

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Jiang, Fan, Yu Ge, Meifang Zhu, Henk Wymeersch e Fredrik Tufvesson. "Low-Complexity Channel Estimation and Localization with Random Beamspace Observations". In ICC 2023 - IEEE International Conference on Communications. IEEE, 2023. http://dx.doi.org/10.1109/icc45041.2023.10278994.

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Reiffers-Masson, Alexandre, Thierry Chonavel e Yezekael Hayel. "Estimating Fiedler Value on Large Networks Based on Random Walk Observations". In ICASSP 2021 - 2021 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP). IEEE, 2021. http://dx.doi.org/10.1109/icassp39728.2021.9413713.

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Soucie, John E. San, Heidi M. Sosik e Yogesh Girdhar. "Gaussian-Dirichlet Random Fields for Inference over High Dimensional Categorical Observations". In 2020 IEEE International Conference on Robotics and Automation (ICRA). IEEE, 2020. http://dx.doi.org/10.1109/icra40945.2020.9196713.

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Palafox, Leon, Laszlo A. Jeni e Hideki Hashimoto. "Using conditional random fields to validate observations in a 4W1H paradigm". In 2011 4th International Conference on Human System Interactions (HSI). IEEE, 2011. http://dx.doi.org/10.1109/hsi.2011.5937347.

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Rapporti di organizzazioni sul tema "Random observations"

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Bucklew, James A., e Stamatis Cambanis. Estimating Random Integrals from Noisy Observations: Sampling Designs and Their Performance. Fort Belvoir, VA: Defense Technical Information Center, dicembre 1985. http://dx.doi.org/10.21236/ada170330.

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Blake, J. B., e R. Mandel. On-Orbit Observations of Single-Event Upset in Harris HM-6508 RAMSs (Random Access Memories): An Update. Fort Belvoir, VA: Defense Technical Information Center, febbraio 1989. http://dx.doi.org/10.21236/ada206266.

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Shiller, Robert, e Pierre Perron. Testing the Random Walk Hypothesis: Power versus Frequency of Observation. Cambridge, MA: National Bureau of Economic Research, aprile 1985. http://dx.doi.org/10.3386/t0045.

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Araujo, María Caridad, Yyannu Cruz-Aguayo, Pedro Carneiro e Norbert Schady. Teacher Quality and Learning Outcomes in Kindergarten. Inter-American Development Bank, dicembre 2016. http://dx.doi.org/10.18235/0011718.

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We assigned two cohorts of kindergarten students, totaling more than 24,000 children, to teachers within schools with a rule that is as-good-as-random. We collected data on children at the beginning of the school year, and applied 12 tests of math, language and executive function (EF) at the end of the year. All teachers were filmed teaching for a full day, and the videos were coded using a well-known classroom observation tool, the Classroom Assessment Scoring System (or CLASS). We find substantial classroom effects: A one-standard deviation increase in classroom quality results in 0.11, 0.11, and 0.07 standard deviation higher test scores in language, math, and EF, respectively. Teacher behaviors, as measured by the CLASS, are associated with higher test scores. Parents recognize better teachers, but do not change their behaviors appreciably to take account of differences in teacher quality .
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Asenath-Smith, Emily, Ross Lieblappen, Susan Taylor, Reed Winter, Terry Melendy, Robert Moser e Robert Haehnel. Observation of crack arrest in ice by high aspect ratio particles during uniaxial compression. Engineer Research and Development Center (U.S.), febbraio 2022. http://dx.doi.org/10.21079/11681/43145.

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In nature, ice frequently contains dissolved solutes or entrapped particles, which modify the microstructure and mechanical properties of ice. Seeking to understand the effect of particle shape and geometry on the mechanical properties of ice, we performed experiments on ice containing 15 wt% silica spheres or rods. Unique to this work was the use of 3-D microstructural imaging in a -10ºC cold room during compressive loading of the sample. The silica particles were present in the ice microstructure as randomly dispersed aggregates within grains and at grain boundaries. While cracks originated in particle-free regions in both sphere- and rod-containing samples, the propagation of cracks was quite different in each type of sample. Cracks propagated uninhibited through aggregates of spherical particles but were observed to arrest at and propagate around aggregates of rods. These results imply that spherical particles do not inhibit grain boundary sliding or increase viscous drag. On the other hand, silica rods were found to span grains, thereby pinning together the microstructure of ice during loading. These results provide insights into mechanisms that can be leveraged to strengthen ice.
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Bäumler, Maximilian, Günther Prokop, Matthias Lehmann e Linda Dziuba-Kaiser. Use Information You Have Never Observed Together: Data Fusion as a Major Step Towards Realistic Test Scenarios. TU Dresden, 2020. http://dx.doi.org/10.26128/2024.3.

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Scenario-based testing is a major pillar in the development and effectiveness assessment of automated driving systems. Thereby, test scenarios address different information layers and situations (normal driving, critical situations and accidents) by using different databases. However, the systematic combination of accident and / or normal driving databases into new synthetic databases can help to obtain scenarios that are as realistic as possible. This paper shows how statistical matching (SM) can be applied to fuse different categorical accident and traffic observation databases. Hereby, the fusion is demonstrated in two use cases, each featuring several fusion methods. In use case 1, a synthetic database was generated out of two accident data samples, whereby 78.7% of the original values could be estimated correctly by a random forest classifier. The same fusion using distance-hot-deck reproduced only 67% of the original values, but better preserved the marginal distributions. A real-world application is illustrated in use case 2, where accident data was fused with over 23,000 car trajectories at one intersection in Germany. We could show that SM is applicable to fuse categorical traffic databases. In future research, the combination of hotdeck- methods and machine learning classifiers needs to be further investigated.
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Gupta, Tejpal, Riddhijyoti Talukdar, Sadhana Kannan, Archya Dasgupta, Abhishek Chatterjee e Vijay Patil. Meta-Analysis of Standard Temozolomide versus Extended Adjuvant Temozolomide following concurrent Radiochemotherapy in newly-diagnosed Glioblastoma (MASTER-G). INPLASY - International Platform of Registered Systematic Review and Meta-analysis Protocols, dicembre 2021. http://dx.doi.org/10.37766/inplasy2021.12.0114.

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Review question / Objective: To assess the safety and efficacy of extended adjuvant temozolomide compared to standard adjuvant temozolomide after concurrent radiochemotherapy in patients with newly-diagnosed glioblastoma. Condition being studied: Newly-diagnosed glioblastoma. Eligibility criteria: Prospective clinical trials randomly assigning patients to extended (>6-cycles) adjuvant TMZ (experimental arm) or standard (6-cycles) adjuvant TMZ will be included. Randomization in an individual study may have been done upfront before concurrent phase (RT/TMZ), after completion of concurrent RT/TMZ and before starting adjuvant phase, or after completion of standard adjuvant TMZ (6-cycles). Emulated RCTs, quasi-randomized trials, propensity matched analyses, non-randomized comparative studies, or observational studies will not be considered in this review.
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Eldar, Avigdor, e Donald L. Evans. Streptococcus iniae Infections in Trout and Tilapia: Host-Pathogen Interactions, the Immune Response Toward the Pathogen and Vaccine Formulation. United States Department of Agriculture, dicembre 2000. http://dx.doi.org/10.32747/2000.7575286.bard.

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In Israel and in the U.S., Streptococcus iniae is responsible for considerable losses in various fish species. Poor understanding of its virulence factors and limited know-how-to of vaccine formulation and administration are the main reasons for the limited efficacy of vaccines. Our strategy was that in order to Improve control measures, both aspects should be equally addressed. Our proposal included the following objectives: (i) construction of host-pathogen interaction models; (ii) characterization of virulence factors and immunodominant antigens, with assessment of their relative importance in terms of protection and (iii) genetic identification of virulence factors and genes, with evaluation of the protective effect of recombinant proteins. We have shown that two different serotypes are involved. Their capsular polysaccharides (CPS) were characterized, and proved to play an important role in immune evasion and in other consequences of the infection. This is an innovative finding in fish bacteriology and resembles what, in other fields, has become apparent in the recent years: S. iniae alters surface antigens. By so doing, the pathogen escapes immune destruction. Immunological assays (agar-gel immunodiffusion and antibody titers) confirmed that only limited cross recognition between the two types occurs and that capsular polysaccharides are immunodominant. Vaccination with purified CPS (as an acellular vaccine) results in protection. In vitro and ex-vivo models have allowed us to unravel additional insights of the host-pathogen interactions. S. iniae 173 (type II) produced DNA fragmentation of TMB-8 cells characteristic of cellular necrosis; the same isolate also prevented the development of apoptosis in NCC. This was determined by finding reduced expression of phosphotidylserine (PS) on the outer membrane leaflet of NCC. NCC treated with this isolate had very high levels of cellular necrosis compared to all other isolates. This cellular pathology was confirmed by observing reduced DNA laddering in these same treated cells. Transmission EM also showed characteristic necrotic cellular changes in treated cells. To determine if the (in vitro) PCD/apoptosis protective effects of #173 correlated with any in vivo activity, tilapia were injected IV with #173 and #164 (an Israeli type I strain). Following injection, purified NCC were tested (in vitro) for cytotoxicity against HL-60 target cells. Four significant observations were made : (i) fish injected with #173 had 100-400% increased cytotoxicity compared to #164 (ii) in vivo activation occurred within 5 minutes of injection; (iii) activation occurred only within the peripheral blood compartment; and (iv) the isolate that protected NCC from apoptosis in vitro caused in vivo activation of cytotoxicity. The levels of in vivo cytotoxicity responses are associated with certain pathogens (pathogen associated molecular patterns/PAMP) and with the tissue of origin of NCC. NCC from different tissue (i.e. PBL, anterior kidney, spleen) exist in different states of differentiation. Random amplified polymorphic DNA (RAPD) analysis revealed the "adaptation" of the bacterium to the vaccinated environment, suggesting a "Darwinian-like" evolution of any bacterium. Due to the selective pressure which has occurred in the vaccinated environment, type II strains, able to evade the protective response elicited by the vaccine, have evolved from type I strains. The increased virulence through the appropriation of a novel antigenic composition conforms with pathogenic mechanisms described for other streptococci. Vaccine efficacy was improved: water-in-oil formulations were found effective in inducing protection that lasted for a period of (at least) 6 months. Protection was evaluated by functional tests - the protective effect, and immunological parameters - elicitation of T- and B-cells proliferation. Vaccinated fish were found to be resistant to the disease for (at least) six months; protection was accompanied by activation of the cellular and the humoral branches.
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Sprague, Joshua, David Kushner, James Grunden, Jamie McClain, Benjamin Grime e Cullen Molitor. Channel Islands National Park Kelp Forest Monitoring Program: Annual report 2014. National Park Service, agosto 2022. http://dx.doi.org/10.36967/2293855.

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Channel Islands National Park (CHIS) has conducted long-term ecological monitoring of the kelp forests around San Miguel, Santa Rosa, Santa Cruz, Anacapa and Santa Barbara Islands since 1982. The original permanent transects were established at 16 sites between 1981 and 1986 with the first sampling beginning in 1982, this being the 33rd year of monitoring. An additional site, Miracle Mile, was established at San Miguel Island in 2001 by a commercial fisherman with assistance from the park. Miracle Mile was partially monitored from 2002 to 2004, and then fully monitored (using all KFM protocols) since 2005. In 2005, 16 additional permanent sites were established to collect baseline data from inside and adjacent to four marine reserves that were established in 2003. Sampling results from all 33 sites mentioned above are included in this report. Funding for the Kelp Forest Monitoring Program (KFM) in 2014 was provided by the National Park Service (NPS). The 2014 monitoring efforts utilized 49 days of vessel time to conduct 1,040 dives for a total of 1,059 hours of bottom time. Population dynamics of a select list of 71 “indicator species” (consisting of taxa or categories of algae, fish, and invertebrates) were measured at the 33 permanent sites. In addition, population dynamics were measured for all additional species of fish observed at the sites during the roving diver fish count. Survey techniques follow the CHIS Kelp Forest Monitoring Protocol Handbook (Davis et al. 1997) and an update to the sampling protocol handbook currently being developed (Kushner and Sprague, in progress). The techniques utilize SCUBA and surface-supplied-air to conduct the following monitoring protocols: 1 m2 quadrats, 5 m2 quadrats, band transects, random point contacts, fish transects, roving diver fish counts, video transects, size frequency measurements, and artificial recruitment modules. Hourly temperature data were collected using remote temperature loggers at 32 sites, the exception being Miracle Mile where there is no temperature logger installed. This annual report contains a brief description of each site including any notable observations or anomalies, a summary of methods used, and monitoring results for 2014. All the data collected during 2014 can be found in the appendices and in an Excel workbook on the NPS Integrated Resource Management Applications (IRMA) portal. In the 2013 annual report (Sprague et al. 2020) several changes were made to the appendices. Previously, annual report density and percent cover data tables only included the current year’s data. Now, density and percent cover data are presented in graphical format and include all years of available monitoring data. Roving diver fish count (RDFC), fish size frequency, natural habitat size frequency, and Artificial Recruitment Module (ARM) size frequency data are now stored on IRMA at https://irma.nps.gov/DataStore/Reference/Profile/2259651. The temperature data graphs in Appendix L include the same graphs that were used in past reports, but include additional violin plot sections that compare monthly means from the current year to past years. In addition to the changes listed above, the layout of the discussion section was reordered by species instead of by site. The status of kelp forests differed among the five park islands. This is a result of a combination of factors including but not limited to, oceanography, biogeography and associated differences in species abundance and composition, as well as sport and commercial fishing pressure. All 33 permanent sites were established in areas that had or were historically known to have had kelp forests in the past. In 2014, 15 of the 33 sites monitored were characterized as developing kelp forest, kelp forest or mature kelp forest. In addition, three sites were in a state of transition. Two sites were part kelp forest and part dominated by Strongylocentrotus purpuratus...
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Weissinger, Rebecca. Evaluation of hanging-garden endemic-plant monitoring at Southeast Utah Group national parks, 2013–2020. A cura di Alice Wondrak Biel. National Park Service, ottobre 2022. http://dx.doi.org/10.36967/2294868.

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Hanging gardens are the most common type of spring at Arches National Park (NP) and Natural Bridges National Monument (NM). They are also present at Canyonlands National Park, but hanging gardens are rare off the Colorado Plateau. Their cliffside setting provides stable access to water without flood disturbance. This combination provides unique habitat that is rich in endemic plant species. The diffuse, seeping emergence of water makes measuring springflow impossible at most sites. Park managers have an interest in monitoring hanging gardens—especially as the climate warms and aridity and water demand both increase. The Northern Colorado Plateau Net-work (NCPN) proposed methods for monitoring seven perennial endemic-plant species at hanging gardens as indicators of spring health and proxies for water availability. Because hanging gardens occur on bedrock outcrops, systematic or random sampling was not possible due to safety concerns and potential resource damage on steep, wet slopes. Examining eight years (2013–2020) of data, this report evaluates the suitability of endemic-plant count data at hanging gardens as a monitoring indicator. It also provides our first evaluation of status and trends at NCPN hanging gardens. The seven species included in monitoring were Rydberg’s thistle (Cirsium rydbergii), Kachina daisy (Erigeron kachinensis), alcove death camas (Zigadenus vaginatus), alcove bog orchid (Habenaria zothecina), cave primrose (Primula specuicola), alcove columbine (Aquilegia micrantha), and Eastwood’s monkeyflower (Mimulus eastwoodiae). Six of the seven species were found at each park. Up to 500 individuals of each species were counted at 42 hanging gardens in Arches NP, 14 hanging gardens in Natural Bridges NM, and 3 hanging gardens in Canyonlands NP. Larger populations were divided into count classes of 501–1,000, 1,001–10,000, and more than 10,000 individuals. Counts from two independent observers and from back-to-back years of sampling were compared for repeatability. Repeatability in count classes was less than 50% for Kachina daisy and Eastwood’s monkeyflower, which both propagate vegetatively via ramets and/or stolons. Repeatability was greater than 90% for only one species, Rydberg’s thistle. The remaining species were categorized in different classes between 15–40% of the time. Independent-observer comparisons were only available for 6.6% of the dataset, but these observations suggested that (1) observer bias was present and (2) the observer with more experience working in hanging gardens generally had higher counts than the observer with less experience in this system. Although repeatability was variable, it was within the range reported by other studies for most species. The NCPN, in discussion with park staff, has elected to make some modifications to the protocol but will continue using endemic plant counts as an indicator of hanging-garden health to maintain a biological variable as a complement to our physical-response data. This is due to their high value to park biodiversity and the difficulty of developing a more robust approach to monitoring in these sites. Endemic-plant monitoring will continue for the five species with the highest repeatability during pilot monitoring and will focus on detecting changes in smaller populations. Most hanging gardens have more than one endemic species present, so several populations can be tracked at each site. Our period of record is relatively brief, and the distribution of endemic-plant populations in different count classes at these sites has not yet shown any statistical trends over time. Be-cause of the large count classes, our methods are more sensitive to showing change in smaller populations (fewer than 500 individuals). Small populations are also of greatest concern to park managers because of their vulnerability to declines or extirpation due to drought. Over-all, more sites had endemic-plant populations of fewer than 100 individuals at the end...
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