Relevant bibliographies by topics / Gaussian grid

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  1. Journal articles
  2. Dissertations / Theses
  3. Book chapters
  4. Conference papers

Academic literature on the topic 'Gaussian grid'

Author: Grafiati
Published: 19 February 2023

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Journal articles on the topic "Gaussian grid"

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Ritchie, Harold. "Semi-Lagrangian Advection on a Gaussian Grid." Monthly Weather Review 115, no. 2 (February 1987): 608–19. http://dx.doi.org/10.1175/1520-0493(1987)115<0608:slaoag>2.0.co;2.

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Sanna, N., T. Castrignano, P. D’Onorio De Meo, D. Carrabino, A. Grandi, G. Morelli, P. Caruso, and V. Barone. "Gaussian grid: a computational chemistry experiment over a web service-oriented grid." Theoretical Chemistry Accounts 117, no. 5-6 (December 15, 2006): 1145–52. http://dx.doi.org/10.1007/s00214-006-0227-9.

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Zhou, Bing, Mark Greenhalgh, and Stewart Greenhalgh. "DC resistivity modelling with a Gaussian quadrature grid." ASEG Extended Abstracts 2006, no. 1 (December 2006): 1–4. http://dx.doi.org/10.1071/aseg2006ab205.

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Courtier, P., and M. Naughton. "A pole problem in the reduced Gaussian grid." Quarterly Journal of the Royal Meteorological Society 120, no. 519 (July 1994): 1389–407. http://dx.doi.org/10.1002/qj.49712051913.

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Li, Tanda, Guy R. Davies, Alexander J. Lyttle, Warrick H. Ball, Lindsey M. Carboneau, and Rafael A. García. "Modelling stars with Gaussian Process Regression: augmenting stellar model grid." Monthly Notices of the Royal Astronomical Society 511, no. 4 (February 21, 2022): 5597–610. http://dx.doi.org/10.1093/mnras/stac467.

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ABSTRACT Grid-based modelling is widely used for estimating stellar parameters. However, stellar model grid is sparse because of the computational cost. This paper demonstrates an application of a machine-learning algorithm using the Gaussian Process (GP) Regression that turns a sparse model grid on to a continuous function. We train GP models to map five fundamental inputs (mass, equivalent evolutionary phase, initial metallicity, initial helium fraction, and the mixing-length parameter) to observable outputs (effective temperature, surface gravity, radius, surface metallicity, and stellar age). We test the GP predictions for the five outputs using off-grid stellar models and find no obvious systematic offsets, indicating good accuracy in predictions. As a further validation, we apply these GP models to characterize 1000 fake stars. Inferred masses and ages determined with GP models well recover true values within one standard deviation. An important consequence of using GP-based interpolation is that stellar ages are more precise than those estimated with the original sparse grid because of the full sampling of fundamental inputs.
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Marasović, Ivan, Željka Milanović, and Tihomir Betti. "Resistance Fluctuations in GaAs Nanowire Grids." Journal of Nanomaterials 2014 (2014): 1–9. http://dx.doi.org/10.1155/2014/428390.

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We present a numerical study on resistance fluctuations in a series of nanowire-based grids. Each grid is made of GaAs nanowires arranged in parallel with metallic contacts crossing all nanowires perpendicularly. Electrical properties of GaAs nanowires known from previous experimental research are used as input parameters in the simulation procedure. Due to the nonhomogeneous doping, the resistivity changes along nanowire. Allowing two possible nanowire orientations (“upwards” or “downwards”), the resulting grid is partially disordered in vertical direction which causes resistance fluctuations. The system is modeled using a two-dimensional random resistor network. Transfer-matrix computation algorithm is used to calculate the total network resistance. It is found that probability density function (PDF) of resistance fluctuations for a series of nanowire grids changes from Gaussian behavior towards the Bramwell-Holdsworth-Pinton distribution when both nanowire orientations are equally represented in the grid.
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AGISHTEIN, M. E., R. BENAV, A. A. MIGDAL, and S. SOLOMON. "NUMERICAL STUDY OF A TWO-POINT CORRELATION FUNCTION AND LIOUVILLE FIELD PROPERTIES IN TWO-DIMENSIONAL QUANTUM GRAVITY." Modern Physics Letters A 06, no. 12 (April 20, 1991): 1115–31. http://dx.doi.org/10.1142/s0217732391001172.

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Two-point Green’s function is measured on the manifolds of a 2-dimensional quantum gravity. The recursive sampling technique is used to generate the triangulations, lattice sizes being up to hundred thousand triangles. The grid Laplacian was inverted by means of the algebraic multi-grid solver. The free field model of the Quantum Gravity assumes the Gaussian behavior of Liouville field and curvature. We measured histograms as well as six momenta of these fields. Our results support the Gaussian assumption.
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Chung, Wonil. "Grid-based Gaussian process models for longitudinal genetic data." Communications for Statistical Applications and Methods 29, no. 1 (January 31, 2022): 745–63. http://dx.doi.org/10.29220/csam.2022.29.1.745.

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Chung, Wonil. "Grid-based Gaussian process models for longitudinal genetic data." Communications for Statistical Applications and Methods 29, no. 1 (January 31, 2022): 65–83. http://dx.doi.org/10.29220/csam.2022.29.1.065.

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Rochas, Michel. "Comments on “Semi-Lagrangian Advection on a Gaussian Grid”." Monthly Weather Review 116, no. 4 (April 1988): 969–70. http://dx.doi.org/10.1175/1520-0493(1988)116<0969:colaoa>2.0.co;2.

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Dissertations / Theses on the topic "Gaussian grid"

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Briant, Régis. "Modélisation multi échelles de l'impact du trafic routier sur la qualité de l'air." Thesis, Paris Est, 2012. http://www.theses.fr/2012PEST1115/document.

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Le trafic routier contribue à la pollution atmosphérique aussi bien à proximité des voies avec des polluants tels que le dioxyde d'azote (NO2), les particules (PM) et certains composés organiques volatils (COV) qu'à des échelles spatiales plus grandes (pollution de fond urbaine et régionale) avec des polluants formés dans l'atmosphère tels que l'ozone (O3) et la fraction secondaire des particules. Étant donné les interactions entre pollution de proximité et pollution de fond, il est souhaitable de combiner en un seul outil de calcul des modèles à échelles locale et régionale. Cette méthode de modélisation multi-échelles a été largement utilisée pour simuler l'impact des émissions de cheminées (sources ponctuelles) avec des modèles de panache traités en sous-maille d'un modèle eulérien tri-dimensionnel. Cependant, une telle méthode n'est pas applicable à un réseau routier en raison des temps de calcul prohibitifs associés à la discrétisation d'une source linéique en un ensemble de sources ponctuelles. Par conséquent, une nouvelle méthode de modélisation multi-échelles a été développée, qui traite les panaches émis par des sources linéiques en sous-maille d'un modèle eulérien. Tout d'abord, une formulation améliorée d'un modèle gaussien de panache linéique a été développée. Ce nouveau modèle à ensuite fait l'objet d'une évaluation détaillée avec des mesures en proximité de routes ainsi qu'avec d'autres modèles gaussiens. La combinaison de ce modèle gaussien et d'un modèle eulérien (Polair3D) a été implémentée dans la plate-forme de modélisation Polyphemus. Les performances (temps de calcul et précision) du nouveau modèle de panache en sous-maille ont été évaluées et comparées aux performances des modèles gaussien et eulérien seuls. Ce modèle multi-échelles traite la chimie des oxydes d'azote (NOx) et des principaux COV. Le traitement multi-échelles a un effet important sur les concentrations de certains polluants en termes de pollutions de proximité et de fond urbain
Roadway traffic contributes to atmospheric pollution near roads, with pollutants such as nitrogen dioxide (NO2), particles (PM) along with some volatile organic compounds (VOC), as well as at larger spatial scales (urban and regional background pollution) with pollutants formed in the atmosphere such as ozone (O3) and the secondary fraction of PM. Because of interactions between local and background pollutants, it is desirable to combine into a single computational tool, regional and local scale models. This multi-scale modeling method has been widely used to simulate the impact of chimney emissions (point sources) with a sub-grid treatment of plume or puff models instead within a 3-dimensional Eulerian model. However, such a method is not applicable to a road network because of the prohibitive computations associated with the line source discretization into a set of point sources. Thus, a new multi-scale modeling method was developed, which treats the plumes emitted from line sources as sub-grid components of an Eulerian model. First, an improved formulation of a Gaussian plume model for line sources was developed. This new model was then subject to a detailed evaluation with near roadway measurements along with other Gaussian models. The incorporation of the Gaussian plume model into an Eulerian model (Polair3D) was implemented as part of the modeling platform Polyphemus. The performance (computational effectiveness and precision) of the new multi-scale model (Plume-in-Grid) was evaluated and compared to those of a stand-alone Gaussian and Eulerian models. The multi-scale model treats nitrogen oxide (NOx) chemistry along with major VOC. The multi-scale treatment has an important effect on the concentration of some pollutants in terms of local and urban background pollution
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Elfarra, Monier Ali. "Two-dimensional Finite Volume Weighted Essentially Non-oscillatory Euler Schemes With Uniform And Non-uniform Grid Coefficients." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/2/12605898/index.pdf.

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In this thesis, Finite Volume Weighted Essentially Non-Oscillatory (FV-WENO) codes for one and two-dimensional discretised Euler equations are developed. The construction and application of the FV-WENO scheme and codes will be described. Also the effects of the grid coefficients as well as the effect of the Gaussian Quadrature on the solution have been tested and discussed. WENO schemes are high order accurate schemes designed for problems with piecewise smooth solutions containing discontinuities. The key idea lies at the high approximation level, where a convex combination of all the candidate stencils is used with certain weights. Those weights are used to eliminate the stencils, which contain discontinuity. WENO schemes have been quite successful in applications, especially for problems containing both shocks and complicated smooth solution structures. The applications tested in this thesis are the Diverging Nozzle, Shock Vortex Interaction, Supersonic Channel Flow, Flow over Bump, and supersonic Staggered Wedge Cascade. The numerical solutions for the diverging nozzle and the supersonic channel flow are compared with the analytical solutions. The results for the shock vortex interaction are compared with the Roe scheme results. The results for the bump flow and the supersonic staggered cascade are compared with results from literature.
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Nguyen, Vu Minh. "Off-Line Signature Verification using Novel Feature Extraction Techniques and Trajectory Recovery." Thesis, Griffith University, 2012. http://hdl.handle.net/10072/368127.

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Feature extraction is an important process in automatic off-line signature verification systems. In this process, only the information that helps to identify the authenticity of questioned signatures is extracted and retained. Amongst the numerous feature extraction techniques investigated by researchers, grid segmentation schemes have been employed more favourably due to their encouraging results. The research presented in this dissertation focuses on improving the performance of Support Vector Machines (SVMs) based off-line signature verification systems using novel feature extraction techniques. The research began with an in-depth investigation and comparative performance analysis of the Modified Direction Feature (MDF), a structural feature extraction technique. Since the MDF is known for its relatively high accuracies in the cursive character recognition problem, it has been suggested that the performance of the MDF would be as encouraging in verifying Western (English) signatures due to the “cursive appearance” of the signatures. The other features employed for comparative studies were the two grid-based features proposed by Francesco Camastra and Wakabayashi et al. (Gradient feature). The former feature captures the information about the distribution of the foreground pixels in each grid cell whilst the latter utilises the directional information available. The comparisons of these state-of-the-art techniques set the foundation for the development of the novel feature extraction techniques proposed. In total, three novel local features and four global features were proposed and investigated. The local features include Gaussian Grid, Curvature Map, Variance and the local features are New Ratio, Energy, Trajectory Length, Moment. Amongst the local features proposed, the Gaussian Grid feature significantly outperformed all the state-of-the-art features mentioned above. Nevertheless, the combination of another particularly small-dimensional local feature, the Variance feature, with the global features also outperformed the MDF and the Camastra features, and closely approximates the performance of the Gradient feature. The total dimension of this feature set was only 33 compared to 120 of the MDF. This finding emphasizes the capability of small-dimensional global features.
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Information and Communication Technology
Science, Environment, Engineering and Technology
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Usta, Fuat. "Sparse grid approximation with Gaussians." Thesis, University of Leicester, 2015. http://hdl.handle.net/2381/33295.

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Motivated by the recent multilevel sparse kernel-based interpolation (MuSIK) algorithm proposed in [Georgoulis, Levesley and Subhan, SIAM J. Sci. Comput., 35(2), pp. A815-A831, 2013], we introduce the new quasi-multilevel sparse interpolation with kernels (Q-MuSIK) via the combination technique. The Q-MuSIK scheme achieves better convergence and run time in comparison with classical quasi-interpolation; namely, the Q-MuSIK algorithm is generally superior to the MuSIK methods in terms of run time in particular in high-dimensional interpolation problems, since there is no need to solve large algebraic systems. We subsequently propose a fast, low complexity, high-dimensional quadrature formula based on Q-MuSIK interpolation of the integrand. We present the results of numerical experimentation for both interpolation and quadrature in Rd, for d = 2, d = 3 and d = 4. In this work we also consider the convergence rates for multilevel quasiinterpolation of periodic functions using Gaussians on a grid. Initially, we have given the single level quasi-interpolation error by using the shifting properties of Gaussian kernel, and have then found an estimate for the multilevel error using the multilevel algorithm for unit function.
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Hata, Alberto Yukinobu. "Road features detection and sparse map-based vehicle localization in urban environments." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/55/55134/tde-08062017-090428/.

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Localization is one of the fundamental components of autonomous vehicles by enabling tasks as overtaking, lane keeping and self-navigation. Urban canyons and bad weather interfere with the reception of GPS satellite signal which prohibits the exclusive use of such technology for vehicle localization in urban places. Alternatively, map-aided localization methods have been employed to enable position estimation without the dependence on GPS devices. In this solution, the vehicle position is given as the place that best matches the sensor measurement to the environment map. Before building the maps, feature sof the environment must be extracted from sensor measurements. In vehicle localization, curbs and road markings have been extensively employed as mapping features. However, most of the urban mapping methods rely on a street free of obstacles or require repetitive measurements of the same place to avoid occlusions. The construction of an accurate representation of the environment is necessary for a proper match of sensor measurements to the map during localization. To prevent the necessity of a manual process to remove occluding obstacles and unobserved areas, a vehicle localization method that supports maps built from partial observations of the environment is proposed. In this localization system,maps are formed by curb and road markings extracted from multilayer laser sensor measurements. Curb structures are detected even in the presence of vehicles that occlude the roadsides, thanks to the use of robust regression. Road markings detector employs Otsu thresholding to analyze infrared remittance data which makes the method insensitive to illumination. Detected road features are stored in two map representations: occupancy grid map (OGM) and Gaussian process occupancy map (GPOM). The first approach is a popular map structure that represents the environment through fine-grained grids. The second approach is a continuous representation that can estimate the occupancy of unseen areas. The Monte Carlo localization (MCL) method was adapted to support the obtained maps of the urban environment. In this sense, vehicle localization was tested in an MCL that supports OGM and an MCL that supports GPOM. Precisely, for MCL based on GPOM, a new measurement likelihood based on multivariate normal probability density function is formulated. Experiments were performed in real urban environments. Maps were built using sparse laser data to verify there ronstruction of non-observed areas. The localization system was evaluated by comparing the results with a high precision GPS device. Results were also compared with localization based on OGM.
No contexto de veículos autônomos, a localização é um dos componentes fundamentais, pois possibilita tarefas como ultrapassagem, direção assistida e navegação autônoma. A presença de edifícios e o mau tempo interferem na recepção do sinal de GPS que consequentemente dificulta o uso de tal tecnologia para a localização de veículos dentro das cidades. Alternativamente, a localização com suporte aos mapas vem sendo empregada para estimar a posição sem a dependência do GPS. Nesta solução, a posição do veículo é dada pela região em que ocorre a melhor correspondência entre o mapa do ambiente e a leitura do sensor. Antes da criação dos mapas, características dos ambientes devem ser extraídas a partir das leituras dos sensores. Dessa forma, guias e sinalizações horizontais têm sido largamente utilizados para o mapeamento. Entretanto, métodos de mapeamento urbano geralmente necessitam de repetidas leituras do mesmo lugar para compensar as oclusões. A construção de representações precisas dos ambientes é essencial para uma adequada associação dos dados dos sensores como mapa durante a localização. De forma a evitar a necessidade de um processo manual para remover obstáculos que causam oclusão e áreas não observadas, propõe-se um método de localização de veículos com suporte aos mapas construídos a partir de observações parciais do ambiente. No sistema de localização proposto, os mapas são construídos a partir de guias e sinalizações horizontais extraídas a partir de leituras de um sensor multicamadas. As guias podem ser detectadas mesmo na presença de veículos que obstruem a percepção das ruas, por meio do uso de regressão robusta. Na detecção de sinalizações horizontais é empregado o método de limiarização por Otsu que analisa dados de reflexão infravermelho, o que torna o método insensível à variação de luminosidade. Dois tipos de mapas são empregados para a representação das guias e das sinalizações horizontais: mapa de grade de ocupação (OGM) e mapa de ocupação por processo Gaussiano (GPOM). O OGM é uma estrutura que representa o ambiente por meio de uma grade reticulada. OGPOM é uma representação contínua que possibilita a estimação de áreas não observadas. O método de localização por Monte Carlo (MCL) foi adaptado para suportar os mapas construídos. Dessa forma, a localização de veículos foi testada em MCL com suporte ao OGM e MCL com suporte ao GPOM. No caso do MCL baseado em GPOM, um novo modelo de verossimilhança baseado em função densidade probabilidade de distribuição multi-normal é proposto. Experimentos foram realizados em ambientes urbanos reais. Mapas do ambiente foram gerados a partir de dados de laser esparsos de forma a verificar a reconstrução de áreas não observadas. O sistema de localização foi avaliado por meio da comparação das posições estimadas comum GPS de alta precisão. Comparou-se também o MCL baseado em OGM com o MCL baseado em GPOM, de forma a verificar qual abordagem apresenta melhores resultados.
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Zaytsev, Victor. "Méthodes stochastiques pour la modélisation d'incertitudes sur les maillages non structurés." Thesis, Paris Sciences et Lettres (ComUE), 2016. http://www.theses.fr/2016PSLEM094/document.

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La simulation des phénomènes physiques exige souvent l’utilisation d’une discrétisation du milieu sous forme de maillage. Un exemple de ce type de situation est la simulation d’écoulement de fluides et la simulation du stress géomécanique pour les gisements pétroliers. Dans ces cas, le milieu étudié n’est pas homogène et l'hypothèse sur l’homogénéité de ce milieu peut mener à des résultats incorrects. C’est pourquoi la simulation des hétérogénéités est très importante pour ce genre de problèmes.Cette thèse est consacrée à la simulation géostatistique des hétérogénéités sur les maillages non-structurés par les méthodes géostatistiques non-linéaires. Le but de cette thèse est la création d’algorithmes de simulation des hétérogénéités directement sur les maillages non-structurés, sans utiliser les maillages fins réguliers intermédiaires et de l’upscaling. On présente deux modèles théoriques pour les simulations des variables continues sur les maillages non-structurés qui sont les deux versions différentes du modèle Gaussien discret (DGM) - DGM 1 et DGM 2. Le modèle théorique utilisé dans cette thèse permet de convertir le problème de simulation sur un maillage non-structuré en un problème de simulation d’un vecteur Gaussien multivarié et l’application de fonctions de transformation adaptées pour chaque élément du vecteur. La simulation de faciès est aussi envisagée en utilisant une généralisation des modèles pluri-Gaussiens et Gaussien tronqués pour les maillages non-structurés.L’application des méthodes développées est illustrée sur un gisement pétrolier - le cas d’étude X (gisement du gaz offshore)
Simulations of physical phenomenon often require discretizing the medium with a mesh. An example of this type of simulation is the simulation of fluid flow through a porous medium and the evaluation of the geomechanical stress in the petroleum reservoir. The studied medium is often not homogeneous and applying a homogeneity hypothesis can lead to incorrect simulation results. That makes simulation of heterogeneities important for this kind of problems.This thesis is devoted to geostatistical simulations of heterogeneities on unstructured grids using methods of non-linear geostatistics. The objective of this work is the development of algorithms for simulating heterogeneities directly on unstructured grids without using intermediate fine scale regular grids and upscaling. We present two theoretical models for geostatistical simulations of continuous parameters on unstructured grids which are different generalizations of the Discrete Gaussian model (DGM) – DGM 1 and DGM 2. The proposed theoretical models enable converting the problem of geostatistical simulation on an unstructured grid into the well-studied problem of simulating multivariate Gaussian random vectors followed by application of block-dependent transformation functions. The problem of simulating facies is also addressed in this work, for which generalizations of pluri-Gaussian and truncated Gaussian simulation models for unstructured grids are proposed.An application of the proposed methods is demonstrated on a case study X, which is an offshore gas reservoir with a tartan-meshed grid
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Jones, Michael William. "Propagation of low power low divergence Gaussian fields in unbiased self-defocusing photorefractive media and their interactions." Thesis, Queensland University of Technology, 2011. https://eprints.qut.edu.au/45618/1/Michael_Jones_Thesis.pdf.

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Many optical networks are limited in speed and processing capability due to the necessity for the optical signal to be converted to an electrical signal and back again. In addition, electronically manipulated interconnects in an otherwise optical network lead to overly complicated systems. Optical spatial solitons are optical beams that propagate without spatial divergence. They are capable of phase dependent interactions, and have therefore been extensively researched as suitable all optical interconnects for over 20 years. However, they require additional external components, initially high voltage power sources were required, several years later, high power background illumination had replaced the high voltage. However, these additional components have always remained as the greatest hurdle in realising the applications of the interactions of spatial optical solitons as all optical interconnects. Recently however, self-focusing was observed in an otherwise self-defocusing photorefractive crystal. This observation raises the possibility of the formation of soliton-like fields in unbiased self-defocusing media, without the need for an applied electrical field or background illumination. This thesis will present an examination of the possibility of the formation of soliton-like low divergence fields in unbiased self-defocusing photorefractive media. The optimal incident beam and photorefractive media parameters for the formation of these fields will be presented, together with an analytical and numerical study of the effect of these parameters. In addition, preliminary examination of the interactions of two of these fields will be presented. In order to complete an analytical examination of the field propagating through the photorefractive medium, the spatial profile of the beam after propagation through the medium was determined. For a low power solution, it was found that an incident Gaussian field maintains its Gaussian profile as it propagates. This allowed the beam at all times to be described by an individual complex beam parameter, while also allowing simple analytical solutions to the appropriate wave equation. An analytical model was developed to describe the effect of the photorefractive medium on the Gaussian beam. Using this model, expressions for the required intensity dependent change in both the real and imaginary components of the refractive index were found. Numerical investigation showed that under certain conditions, a low powered Gaussian field could propagate in self-defocusing photorefractive media with divergence of approximately 0.1 % per metre. An investigation into the parameters of a Ce:BaTiO3 crystal showed that the intensity dependent absorption is wavelength dependent, and can in fact transition to intensity dependent transparency. Thus, with careful wavelength selection, the required intensity dependent change in both the real and imaginary components of the refractive index for the formation of a low divergence Gaussian field are physically realisable. A theoretical model incorporating the dependence of the change in real and imaginary components of the refractive index on propagation distance was developed. Analytical and numerical results from this model are congruent with the results from the previous model, showing low divergence fields with divergence less than 0.003 % over the propagation length of the photorefractive medium. In addition, this approach also confirmed the previously mentioned self-focusing effect of the self-defocusing media, and provided an analogy to a negative index GRIN lens with an intensity dependent focal length. Experimental results supported the findings of the numerical analysis. Two low divergence fields were found to possess the ability to interact in a Ce:BaTiO3 crystal in a soliton-like fashion. The strength of these interactions was found to be dependent on the degree of divergence of the individual beams. This research found that low-divergence fields are possible in unbiased self-defocusing photorefractive media, and that soliton-like interactions between two of these fields are possible. However, in order for these types of fields to be used in future all optical interconnects, the manipulation of these interactions, together with the ability for these fields to guide a second beam at a different wavelength, must be investigated.
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Ciaroni, Riccardo. "Stima dello stato nelle reti di distribuzione." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2018. http://amslaurea.unibo.it/17249/.

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La stima dello stato di un sistema elettrico rappresenta un processo di stima di un gruppo di variabili di stato, in un preciso istante di tempo, che lo descrivano in modo univoco partendo da un certo numero di misure tenendo conto delle incertezze ad esse correlate. Conoscere lo stato di un sistema è fondamentale per una gestione efficiente, in sicurezza e nel rispetto dei vincoli tecnici, delle reti elettriche. La tesi ha come obiettivo la procedura di stima dello stato mediante il metodo dei minimi quadrati ed in particolare alla sua applicazione a reti di distribuzione dell’energia elettrica. La stima dello stato di reti di distribuzione pone problemi particolari essenzialmente legati al gran numero di carichi, e quindi di nodi, in genere non monitorati in tempo reale, e alla lunghezza limitata delle linee, specie in reti urbane. Il gran numero di nodi e l’assenza di misure in numero sufficiente a rendere la rete osservabile e La tesi analizza tali aspetti mediante applicazione di un algoritmo di stima dello stato, disponibile nella libreria Matpower di Matlab, a due reti test di diverse caratteristiche. La prima è una rete test IEEE disponibile in letteratura, caratterizzata da lunghi feeder rurali a tensione nominale 4,16 kV, ed una porzione della rete di distribuzione AMAIE di Sanremo, caratterizzata da feeder urbani in cavo, a tensione nominale 15 kV. Le principali difficoltà riscontrate nell’esecuzione di calcoli di lod flow e stima dello stato della rete reale sono risultati legati alla complessità della topologia della rete, al gran numero di nodi utenti finali e alla presenza di misure distribuite solo in un determinato porzione della rete, dalla presenza di un gran numero di misure in bassa tensione ed alla necessità di identificare la rete a partire dalla sua descrizione contenuta in un file avente un formato particolare (hdc).
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Ospald, Felix. "Contributions to the Simulation and Optimization of the Manufacturing Process and the Mechanical Properties of Short Fiber-Reinforced Plastic Parts." 2019. https://monarch.qucosa.de/id/qucosa%3A36522.

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This thesis addresses issues related to the simulation and optimization of the injection molding of short fiber-reinforced plastics (SFRPs). The injection molding process is modeled by a two phase flow problem. The simulation of the two phase flow is accompanied by the solution of the Folgar-Tucker equation (FTE) for the simulation of the moments of fiber orientation densities. The FTE requires the solution of the so called 'closure problem'', i.e. the representation of the 4th order moments in terms of the 2nd order moments. In the absence of fiber-fiber interactions and isotropic initial fiber density, the FTE admits an analytical solution in terms of elliptic integrals. From these elliptic integrals, the closure problem can be solved by a simple numerical inversion. Part of this work derives approximate inverses and analytical inverses for special cases of fiber orientation densities. Furthermore a method is presented to generate rational functions for the computation of arbitrary moments in terms of the 2nd order closure parameters. Another part of this work treats the determination of effective material properties for SFRPs by the use of FFT-based homogenization methods. For these methods a novel discretization scheme, the 'staggered grid'' method, was developed and successfully tested. Furthermore the so called 'composite voxel'' approach was extended to nonlinear elasticity, which improves the approximation of material properties at the interfaces and allows the reduction of the model order by several magnitudes compared to classical approaches. Related the homogenization we investigate optimal experimental designs to robustly determine effective elastic properties of SFRPs with the least number of computer simulations. Finally we deal with the topology optimization of injection molded parts, by extending classical SIMP-based topology optimization with an approximate model for the fiber orientations. Along with the compliance minimization by topology optimization we also present a simple shape optimization method for compensation of part warpage for an black-box production process.:Acknowledgments v Abstract vii Chapter 1. Introduction 1 1.1 Motivation 1 1.2 Nomenclature 3 Chapter 2. Numerical simulation of SFRP injection molding 5 2.1 Introduction 5 2.2 Injection molding technology 5 2.3 Process simulation 6 2.4 Governing equations 8 2.5 Numerical implementation 18 2.6 Numerical examples 25 2.7 Conclusions and outlook 27 Chapter 3. Numerical and analytical methods for the exact closure of the Folgar-Tucker equation 35 3.1 Introduction 35 3.2 The ACG as solution of Jeffery's equation 35 3.3 The exact closure 36 3.4 Carlson-type elliptic integrals 37 3.5 Inversion of R_D-system 40 3.6 Moment tensors of the angular central Gaussian distribution on the n-sphere 49 3.7 Experimental evidence for ACG distribution hypothesis 54 3.8 Conclusions and outlook 60 Chapter 4. Homogenization of SFRP materials 63 4.1 Introduction 63 4.2 Microscopic and macroscopic model of SFRP materials 63 4.3 Effective linear elastic properties 65 4.4 The staggered grid method 68 4.5 Model order reduction by composite voxels 80 4.6 Optimal experimental design for parameter identification 93 Chapter 5. Optimization of parts produced by SFRP injection molding 103 5.1 Topology optimization 103 5.2 Warpage compensation 110 Chapter 6. Conclusions and perspectives 115 Appendix A. Appendix 117 A.1 Evaluation of R_D in Python 117 A.2 Approximate inverse for R_D in Python 117 A.3 Inversion of R_D using Newton's/Halley's method in Python 117 A.4 Inversion of R_D using fixed point method in Python 119 A.5 Moment computation using SymPy 120 A.6 Fiber collision test 122 A.7 OED calculation of the weighting matrix 123 A.8 OED Jacobian of objective and constraints 123 Appendix B. Theses 125 Bibliography 127
Diese Arbeit befasst sich mit Fragen der Simulation und Optimierung des Spritzgießens von kurzfaserverstärkten Kunststoffen (SFRPs). Der Spritzgussprozess wird durch ein Zweiphasen-Fließproblem modelliert. Die Simulation des Zweiphasenflusses wird von der Lösung der Folgar-Tucker-Gleichung (FTE) zur Simulation der Momente der Faserorientierungsdichten begleitet. Die FTE erfordert die Lösung des sogenannten 'Abschlussproblems'', d. h. die Darstellung der Momente 4. Ordnung in Form der Momente 2. Ordnung. In Abwesenheit von Faser-Faser-Wechselwirkungen und anfänglich isotroper Faserdichte lässt die FTE eine analytische Lösung durch elliptische Integrale zu. Aus diesen elliptischen Integralen kann das Abschlussproblem durch eine einfache numerische Inversion gelöst werden. Ein Teil dieser Arbeit leitet approximative Inverse und analytische Inverse für spezielle Fälle von Faserorientierungsdichten her. Weiterhin wird eine Methode vorgestellt, um rationale Funktionen für die Berechnung beliebiger Momente in Bezug auf die Abschlussparameter 2. Ordnung zu generieren. Ein weiterer Teil dieser Arbeit befasst sich mit der Bestimmung effektiver Materialeigenschaften für SFRPs durch FFT-basierte Homogenisierungsmethoden. Für diese Methoden wurde ein neuartiges Diskretisierungsschema 'staggerd grid'' entwickelt und erfolgreich getestet. Darüber hinaus wurde der sogenannte 'composite voxel''-Ansatz auf die nichtlineare Elastizität ausgedehnt, was die Approximation der Materialeigenschaften an den Grenzflächen verbessert und die Reduzierung der Modellordnung um mehrere Größenordnungen im Vergleich zu klassischen Ansätzen ermöglicht. Im Zusammenhang mit der Homogenisierung untersuchen wir optimale experimentelle Designs, um die effektiven elastischen Eigenschaften von SFRPs mit der geringsten Anzahl von Computersimulationen zuverlässig zu bestimmen. Schließlich beschäftigen wir uns mit der Topologieoptimierung von Spritzgussteilen, indem wir die klassische SIMP-basierte Topologieoptimierung um ein Näherungsmodell für die Faserorientierungen erweitern. Neben der Compliance-Minimierung durch Topologieoptimierung stellen wir eine einfache Formoptimierungsmethode zur Kompensation von Teileverzug für einen Black-Box-Produktionsprozess vor.:Acknowledgments v Abstract vii Chapter 1. Introduction 1 1.1 Motivation 1 1.2 Nomenclature 3 Chapter 2. Numerical simulation of SFRP injection molding 5 2.1 Introduction 5 2.2 Injection molding technology 5 2.3 Process simulation 6 2.4 Governing equations 8 2.5 Numerical implementation 18 2.6 Numerical examples 25 2.7 Conclusions and outlook 27 Chapter 3. Numerical and analytical methods for the exact closure of the Folgar-Tucker equation 35 3.1 Introduction 35 3.2 The ACG as solution of Jeffery's equation 35 3.3 The exact closure 36 3.4 Carlson-type elliptic integrals 37 3.5 Inversion of R_D-system 40 3.6 Moment tensors of the angular central Gaussian distribution on the n-sphere 49 3.7 Experimental evidence for ACG distribution hypothesis 54 3.8 Conclusions and outlook 60 Chapter 4. Homogenization of SFRP materials 63 4.1 Introduction 63 4.2 Microscopic and macroscopic model of SFRP materials 63 4.3 Effective linear elastic properties 65 4.4 The staggered grid method 68 4.5 Model order reduction by composite voxels 80 4.6 Optimal experimental design for parameter identification 93 Chapter 5. Optimization of parts produced by SFRP injection molding 103 5.1 Topology optimization 103 5.2 Warpage compensation 110 Chapter 6. Conclusions and perspectives 115 Appendix A. Appendix 117 A.1 Evaluation of R_D in Python 117 A.2 Approximate inverse for R_D in Python 117 A.3 Inversion of R_D using Newton's/Halley's method in Python 117 A.4 Inversion of R_D using fixed point method in Python 119 A.5 Moment computation using SymPy 120 A.6 Fiber collision test 122 A.7 OED calculation of the weighting matrix 123 A.8 OED Jacobian of objective and constraints 123 Appendix B. Theses 125 Bibliography 127
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Book chapters on the topic "Gaussian grid"

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Jia, Bin, and Ming Xin. "Grid-based Gaussian Nonlinear Estimation." In Grid-based Nonlinear Estimation and Its Applications, 52–106. Boca Raton, FL : CRC Press, Taylor & Francis Group, 2019. | “A science publishers book.”: CRC Press, 2019. http://dx.doi.org/10.1201/9781315193212-4.

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Nishikawa, Takeshi, Umpei Nagashima, and Satoshi Sekiguchi. "Design and Implementation of Intelligent Scheduler for Gaussian Portal on Quantum Chemistry Grid." In Lecture Notes in Computer Science, 244–53. Berlin, Heidelberg: Springer Berlin Heidelberg, 2003. http://dx.doi.org/10.1007/3-540-44863-2_25.

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Eltamaly, Ali M., Ahmed A. Zaki Diab, and Ahmed G. Abo-Khalil. "Robust Control Based on H∞ and Linear Quadratic Gaussian of Load Frequency Control of Power Systems Integrated with Wind Energy System." In Control and Operation of Grid-Connected Wind Energy Systems, 73–86. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-64336-2_4.

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Prado, R. P., J. Braun, J. Krettek, F. Hoffmann, S. García-Galán, J. E. Muñoz Expósito, and T. Bertram. "Gaussian Mixture Models vs. Fuzzy Rule-Based Systems for Adaptive Meta-scheduling in Grid/Cloud Computing." In Advances in Intelligent Systems and Computing, 295–304. Berlin, Heidelberg: Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-642-30864-2_28.

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Gomez-Reino, Carlos, Maria Victoria Perez, and Carmen Bao. "GRIN Lenses for Gaussian Illumination." In Gradient-Index Optics, 87–107. Berlin, Heidelberg: Springer Berlin Heidelberg, 2002. http://dx.doi.org/10.1007/978-3-662-04741-5_4.

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Sedghi, Hanie, and Edmond Jonckheere. "On the Conditional Mutual Information in the Gaussian–Markov Structured Grids." In Information and Control in Networks, 277–97. Cham: Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-02150-8_9.

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Palomares-Salas, José Carlos, Juan José González de la Rosa, José María Sierra-Fernández, Agustín Agüera-Pérez, Álvaro Jiménez-Montero, and Rosa Piotrkowski. "Integration of Higher-Order Time-Frequency Statistics and Neural Networks." In Advances in Computational Intelligence and Robotics, 154–72. IGI Global, 2016. http://dx.doi.org/10.4018/978-1-5225-0063-6.ch006.

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Higher-order statistics demonstrate their innovative features to characterize power quality events, beyond the traditional and limited Gaussian perspective, integrating time-frequency features and within the frame of a Higher-Order Neural Network (HONN). With the massive advent of smart measurement equipment in the electrical grid (Smart Grid), and in the frame of high penetration scenarios of renewable energy resources, the necessity dynamic power quality monitoring is gaining even more importance in order to identify the suspicious sources of the perturbation, which are nonlinear and unpredictable in nature. This eventually would satisfy the demand of intelligent instruments, capable not only of detecting the type of perturbation, but also the source of its origin in a scenario of distributed energy resources.
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Xu, Junjun, Haiyong Luo, Fang Zhao, Rui Tao, Yiming Lin, and Hui Li. "The WiMap." In Global Applications of Pervasive and Ubiquitous Computing, 31–41. IGI Global, 2013. http://dx.doi.org/10.4018/978-1-4666-2645-4.ch004.

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As positioning technology is an important foundation of the Internet of Things, a dynamic indoor WLAN localization system is proposed in this paper. This paper mainly concentrates on the design and implementation of the WiMap-a dynamic indoor WLAN localization system, which employs grid-based localization method using RSS (received signal strength). To achieve high localization accuracy and low computational complexity, Gaussian mixture model is applied to approximate the signal distribution and a ROI (region of interest) is defined to limit the search region. The authors also discuss other techniques like AP selection and threshold control, which affects the localization accuracy. The experimental results indicate that an accuracy of 3m with 73.8% probability can be obtained in WiMap. Moreover, the running time is reduced greatly with limited ROI method.
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Zhan, Zhimin, Jie Xing, Ke Zhang, Xiao Li, and Bin Luo. "Face to Electricity Data Transmission of Composite Differential Private Recommend Method Research." In Advances in Transdisciplinary Engineering. IOS Press, 2022. http://dx.doi.org/10.3233/atde220096.

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With the construction and development of China’s smart power grid, it has realized the power information interconnection, but also realized the collection of electricity user information fine, to bring convenience to users, but also led to the risk of privacy leakage. The traditional method of privacy protection has certain limitations to the protection of users’ privacy data: only to a certain extent to protect the privacy of users. With the advent of advanced technologies such as machine learning, the ability of attackers to speculate on privacy has improved significantly, and traditional methods of privacy protection have been difficult to work with. This paper summarizes and analyzes the centralized differential privacy method and the localized differential privacy method in smart grid data transmission. The characteristics and advantages of The Laplace mechanism, Gaussian mechanism, and index mechanism are analyzed and compared on the addition of noise disturbance mechanism in differential privacy method. In addition, this paper introduces the current researchers on the local differential privacy methods and noise-making mechanism improvement methods. Finally, a K-Means user clustering method based on K-Means is proposed, the main method is to do K-Means clustering analysis based on the sensitivity of different user groups, and then use different differential privacy methods according to different group categories.
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Prakash Yadav, Saty, and Amit Kumar Singh. "Performance Analysis of CCS on Inclined Plane using Fuzzy-PID Controller." In Artificial Intelligence and Natural Algorithms, 320–50. BENTHAM SCIENCE PUBLISHERS, 2022. http://dx.doi.org/10.2174/9789815036091122010020.

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Nowadays, in the automation industries, the Cruise Control System (CCS) is one of the essential aspects, and it is necessary to have a well-designed controller that can suit a new improvement in innovation. The CCS is a very famous and important model in control system engineering. The fundamental objective of CCS is to regulate vehicle speed depending upon the chosen speed. The CCS is an example of a close loop control system. Speedometer is utilized in the feedback path for measurement of the speed. This is a simple model used to solve the many problems of drivers like road accidents, weariness, etc. In this paper, we analyze the performance of different controllers such as Proportional-Integral-Derivative (PID) controller, the fuzzy logic controller (FLC) and the fuzzy-PID (F-PID) controller in the different situations on the road, such as friction, road grad, or angle of inclination to attain the chosen speed of the vehicles. The tuning of PID parameters is done using the method of Ziegler-Nichols, and FLC uses the gaussian Membership Function (MF) in this paper. The MF is a graph that lies between zero and one. It indicates the mapping of every point in the input state and the values of MF. The mathematical model of this system is considers the road grad and the friction. Finally, in this paper, we see the response of models with and without a controller in different situations on the road.
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Conference papers on the topic "Gaussian grid"

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Endo, T., and K. Taura. "Highly latency tolerant Gaussian elimination." In The 6th IEEE/ACM International Workshop on Grid Computing, 2005. IEEE, 2005. http://dx.doi.org/10.1109/grid.2005.1542729.

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Schafer, Benjamin, Dirk Witthaut, and Marc Timme. "How Decentral Smart Grid Control Limits Non-Gaussian Power Grid Frequency Fluctuations." In 2018 IEEE Conference on Control Technology and Applications (CCTA). IEEE, 2018. http://dx.doi.org/10.1109/ccta.2018.8511400.

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Son, Kyuho, and Dongsoo Han. "Grid-based Gaussian Modeling for Cellular Positioning (poster)." In MobiSys '19: The 17th Annual International Conference on Mobile Systems, Applications, and Services. New York, NY, USA: ACM, 2019. http://dx.doi.org/10.1145/3307334.3328718.

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Mori, Hiroyuki, and Kaoru Nakano. "LMP forecasting with prefiltered Gaussian process." In 2014 IEEE Symposium on Computational Intelligence Applications in Smart Grid (CIASG). IEEE, 2014. http://dx.doi.org/10.1109/ciasg.2014.7011555.

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Zhou, Cheng, Yi-hua Tan, Jin-wen Tian, and Wen-po Ma. "Gaussian kernel-based variable-grid image super-resolution reconstruction." In Sixth International Symposium on Multispectral Image Processing and Pattern Recognition, edited by Henri Maître, Hong Sun, Bangjun Lei, and Jufu Feng. SPIE, 2009. http://dx.doi.org/10.1117/12.831331.

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Huang, Xu, Yujiu Yang, and Xianyu Bao. "Grid-based Gaussian Processes Factorization Machine for Recommender Systems." In ICMLC 2017: 2017 the 9th International Conference on Machine Learning and Computing. New York, NY, USA: ACM, 2017. http://dx.doi.org/10.1145/3055635.3056633.

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Wei, Tongming, Ruisheng Zhang, Xianrong Su, Shilin Chen, and Lian Li. "GaussianScriptEditor: An Editor for Gaussian Scripting Language for Grid Environment." In 2009 Eighth International Conference on Grid and Cooperative Computing (GCC). IEEE, 2009. http://dx.doi.org/10.1109/gcc.2009.49.

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Rittenhouse, Benjamin, and Alok Sinha. "Optimal Sliding Mode Gaussian Controller for Hydropower Plant With Grid Dynamics." In ASME 2013 Dynamic Systems and Control Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/dscc2013-3926.

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This paper examines the performance of an optimal sliding mode Gaussian (OSG) controller for the regulation of a hydropower plant implemented in the modeling program SIMSEN. The controller is designed to regulate grid frequency and includes the dynamics of the wicket gate servo system, turbine, and grid. Simulation results for OSG control are compared to those of more traditional LQG and PI controllers. Simulation shows that OSG control provides superior performance for the nominal system and for the system with parametric uncertainties.
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Zhang, Qingyun, Rui Shi, Haiyang Geng, Jiaoli Liu, Xin Jin, Hairui Xing, and Dongxia Bai. "Power Grid Inspection Image Denoising for Mixed Poisson-Gaussian Noise." In 2022 IEEE 5th International Conference on Information Systems and Computer Aided Education (ICISCAE). IEEE, 2022. http://dx.doi.org/10.1109/iciscae55891.2022.9927530.

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Singh, Sumeet, and Harpreet Kaur. "Energy aware Internet of Things using Gaussian membership function." In 2016 Fourth International Conference on Parallel, Distributed and Grid Computing (PDGC). IEEE, 2016. http://dx.doi.org/10.1109/pdgc.2016.7913138.

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